Review of current progress in nanometrology with the helium ion microscope

NASA Astrophysics Data System (ADS)

Postek, Michael T.; Vladár, András; Archie, Charles; Ming, Bin

2011-02-01

Scanning electron microscopy has been employed as an imaging and measurement tool for more than 50 years and it continues as a primary tool in many research and manufacturing facilities across the world. A new challenger to this work is the helium ion microscope (HIM). The HIM is a new imaging and metrology technology. Essentially, substitution of the electron source with a helium ion source yields a tool visually similar in function to the scanning electron microscope, but very different in the fundamental imaging and measurement process. The imaged and measured signal originates differently than in the scanning electron microscope and that fact and its single atom source diameter may be able to push the obtainable resolution lower, provide greater depth-of-field and ultimately improve the metrology. Successful imaging and metrology with this instrument entails understanding and modeling of new ion beam/specimen interaction physics. As a new methodology, HIM is beginning to show promise and the abundance of potentially advantageous applications for nanometrology has yet to be fully exploited. This paper discusses some of the progress made at NIST in collaboration with IBM to understand the science behind this new technology.

Alternative Approach to Teaching Veterinary Anatomy: A Progress Report

ERIC Educational Resources Information Center

Hullinger, Ronald; Render, Gary F.

1975-01-01

Students in microscopic anatomy at Purdue University School of Veterinary Medicine selected a self-directed or teacher-directed approach to the course. Adoption of the experimental approach described here increased faculty time for evaluating student progress but was supportive of student development particularly in cognitive skills and affective…

Using Long-Term Time-Lapse Imaging of Mammalian Cell Cycle Progression for Laboratory Instruction and Analysis

ERIC Educational Resources Information Center

Hinchcliffe, Edward H.

2005-01-01

Cinemicrography--the capture of moving cellular sequences through the microscope--has been influential in revealing the dynamic nature of cellular behavior. One of the more dramatic cellular events is mitosis, the division of sister chromatids into two daughter cells. Mitosis has been extensively studied in a variety of organisms, both…

The epidemiology of malaria in adults in a rural area of southern Mozambique.

PubMed

Mayor, Alfredo; Aponte, John J; Fogg, Carole; Saúte, Francisco; Greenwood, Brian; Dgedge, Martinho; Menendez, Clara; Alonso, Pedro L

2007-01-17

Epidemiological studies of malaria in adults who live in malaria endemic areas are scarce. More attention to the natural history of malaria affecting adults is needed to understand the dynamics of malaria infection and its interaction with the immune system. The present study was undertaken to investigate the clinical, parasitological and haematological status of adults exposed to malaria, and to characterize parasites in these individuals who progressively acquire protective immunity. A cross-sectional survey of 249 adults was conducted in a malaria endemic area of Mozambique. Clinical, parasitological and haematological status of the study population was recorded. Sub-microscopic infections and multiplicity of infections were investigated using polymerase chain reaction (PCR) and restriction fragment length polymorphism of Plasmodium falciparum merozoite surface protein 2 (msp2). Prevalence of P. falciparum infection by microscopy (14%) and PCR (42%) decreased progressively during adulthood, in parallel with an increase in the prevalence of sub-microscopic infections. Anaemia was only related to parasitaemia as detected by PCR. Multiplicity of infection decreased with age and was higher in subjects with high P. falciparum densities, highlighting density-dependent constraints upon the PCR technique. Adults of Manhiça progressively develop non-sterile, protective immunity against P. falciparum malaria. The method of parasite detection has a significant effect on the observed natural history of malaria infections. A more sensitive definition of malaria in adults should be formulated, considering symptoms such as diarrhoea, shivering and headache, combined with the presence of parasitaemia.

Joint Services Electronics Program Annual Progress Report.

DTIC Science & Technology

1987-10-15

polarizability of free carriers in the semiconductor perturb the index of refraction which can be detected in a Nomarski -type optical interferometer. For...interferomters. However, the charge probe relies on a different physical effect and operates by interferometrically detecting the phase change induced in an... Nomarski microscope systems. These techniques will be applied, eventually, in our real-time V.. scanning optical microscope described below. Recently

Scanning probe microscopy of biomedical interfaces

NASA Astrophysics Data System (ADS)

Vansteenkiste, S. O.; Davies, M. C.; Roberts, C. J.; Tendler, S. J. B.; Williams, P. M.

1998-02-01

The development of the scanning probe microscopes over the past decade has provided a number of exciting new surface analytical techniques making a significant progress in the characterisation of biomedical interfaces. In this review, several examples are presented to illustrate that SPM is a powerful and promising tool for surface investigations including biomolecules, cell membranes, polymers and even living cells. The ability of the SPM instrument to monitor adhesion phenomena and provide quantitative information about intermolecular interactions is also described. Moreover, the huge potential of the scanning probe microscopes to study dynamic processes at interfaces under nearly physiological conditions is highlighted. Novel applications in the field of biochemistry, microbiology, biomaterial engineering, drug delivery and even medicine are discussed.

Microscopic investigation of cavitation erosion damage in metals

NASA Technical Reports Server (NTRS)

Hackworh, J. V.; Adler, W. F.

1974-01-01

The results of research to identify the cavitation erosion damage mechanisms at the microscopic level for three metals (aluminum, stainless steel, and titanium) representing a range of properties and microstructure are presented. The metals were exposed to cavitation generated in distilled water by a 20-kHz ultrasonic facility operating at a vibration amplitude of 2 mils. Representative properties of the metals and experimental details are summarized. Replicas of the eroded surfaces of the specimens obtained periodically during exposure were examined with a transmission electron microscope to follow progression of the erosion damage and identify dominant erosion mechanisms as a function of exposure time. Eroded surfaces of selected specimens were also examined with a scanning electron microscope to assist in the interpretation.

Five years of experience teaching pathology to dental students using the WebMicroscope

PubMed Central

2011-01-01

Background We describe development and evaluation of the user-friendly web based virtual microscopy - WebMicroscope for teaching and learning dental students basic and oral pathology. Traditional students microscopes were replaced by computer workstations. Methods The transition of the basic and oral pathology courses from light to virtual microscopy has been completed gradually over a five-year period. A pilot study was conducted in academic year 2005/2006 to estimate the feasibility of integrating virtual microscopy into a traditional light microscopy-based pathology course. The entire training set of glass slides was subsequently converted to virtual slides and placed on the WebMicroscope server. Giving access to fully digitized slides on the web with a browser and a viewer plug-in, the computer has become a perfect companion of the student. Results The study material consists now of over 400 fully digitized slides which covering 15 entities in basic and systemic pathology and 15 entities in oral pathology. Digitized slides are linked with still macro- and microscopic images, organized with clinical information into virtual cases and supplemented with text files, syllabus, PowerPoint presentations and animations on the web, serving additionally as material for individual studies. After their examinations, the students rated the use of the software, quality of the images, the ease of handling the images, and the effective use of virtual slides during the laboratory practicals. Responses were evaluated on a standardized scale. Because of the positive opinions and support from the students, the satisfaction surveys had shown a progressive improvement over the past 5 years. The WebMicroscope as a didactic tool for laboratory practicals was rated over 8 on a 1-10 scale for basic and systemic pathology and 9/10 for oral pathology especially as various students’ suggestions were implemented. Overall, the quality of the images was rated as very good. Conclusions An overwhelming majority of our students regarded a possibility of using virtual slides at their convenience as highly desirable. Our students and faculty consider the use of the virtual microscope for the study of basic as well as oral pathology as a significant improvement over the light microscope. PMID:21489183

Pulp tissue in sex determination: A fluorescent microscopic study

PubMed Central

Nayar, Amit; Singh, Harkanwal Preet; Leekha, Swati

2014-01-01

Aims: To determine and compare the reliability of pulp tissue in determination of sex and to analyze whether caries have any effect on fluorescent body test. Materials and Methods: This study was carried on 50 maxillary and mandibular teeth (25 male teeth and 25 female teeth), which were indicated for extraction. The teeth are categorized into 5 groups, 10 each (5 from males and 5 from females) on the basis of caries progression. The pulp cells are stained with quinacrine hydrochloride and observed with fluorescent microscope for fluorescent body. Gender is determined by identification of Y chromosome fluorescence in dental pulp. Results: Fluorescent bodies were found to be more in sound teeth in males as the caries increase the mean percentage of fluorescent bodies observed decreases in males. We also observed the fluorescent spots in females, and the value of the spot increases in female as the caries progresses, thereby giving false positive results in females. Conclusion: Sex determination by fluorescent staining of the Y chromosome is a reliable technique in teeth with healthy pulps or caries with enamel or up to half way of dentin. Teeth with caries involving pulp cannot be used for sex determination. PMID:25125912

Optical-sectioning microscopy of protoporphyrin IX fluorescence in human gliomas: standardization and quantitative comparison with histology

NASA Astrophysics Data System (ADS)

Wei, Linpeng; Chen, Ye; Yin, Chengbo; Borwege, Sabine; Sanai, Nader; Liu, Jonathan T. C.

2017-04-01

Systemic delivery of 5-aminolevulinic acid leads to enhanced fluorescence image contrast in many tumors due to the increased accumulation of protoporphyrin IX (PpIX), a fluorescent porphyrin that is associated with tumor burden and proliferation. The value of PpIX-guided resection of malignant gliomas has been demonstrated in prospective randomized clinical studies in which a twofold greater extent of resection and improved progression-free survival have been observed. In low-grade gliomas and at the diffuse infiltrative margins of all gliomas, PpIX fluorescence is often too weak to be detected with current low-resolution surgical microscopes that are used in operating rooms. However, it has been demonstrated that high-resolution optical-sectioning microscopes are capable of detecting the sparse and punctate accumulations of PpIX that are undetectable via conventional low-power surgical fluorescence microscopes. To standardize the performance of high-resolution optical-sectioning devices for future clinical use, we have developed an imaging phantom and methods to ensure that the imaging of PpIX-expressing brain tissues can be performed reproducibly. Ex vivo imaging studies with a dual-axis confocal microscope demonstrate that these methods enable the acquisition of images from unsectioned human brain tissues that quantitatively and consistently correlate with images of histologically processed tissue sections.

Fundamental Physics with Electroweak Probes of Nuclei

NASA Astrophysics Data System (ADS)

Pastore, Saori

2018-02-01

The past decade has witnessed tremendous progress in the theoretical and computational tools that produce our understanding of nuclei. A number of microscopic calculations of nuclear electroweak structure and reactions have successfully explained the available experimental data, yielding a complex picture of the way nuclei interact with electroweak probes. This achievement is of great interest from the pure nuclear-physics point of view. But it is of much broader interest too, because the level of accuracy and confidence reached by these calculations opens up the concrete possibility of using nuclei to address open questions in other sub-fields of physics, such as, understanding the fundamental properties of neutrinos, or the particle nature of dark matter. In this talk, I will review recent progress in microscopic calculations of electroweak properties of light nuclei, including electromagnetic moments, form factors and transitions in between lowlying nuclear states along with preliminary studies for single- and double-beta decay rates. I will illustrate the key dynamical features required to explain the available experimental data, and, if time permits, present a novel framework to calculate neutrino-nucleus cross sections for A > 12 nuclei.

Twisted ribbon structure of paired helical filaments revealed by atomic force microscopy.

PubMed Central

Pollanen, M. S.; Markiewicz, P.; Bergeron, C.; Goh, M. C.

1994-01-01

Progressive deposition of phosphorylated tau into the paired helical filaments (PHF) that compose neurofibrillary tangles, dystrophic neurites, and neuropil threads is an obligate feature of Alzheimer's disease. The standard model of PHF structure, derived from electron microscopic studies, suggests that two 8- to 10-nm filaments each composed of three to four protofilaments are wound into a helix with a maximal diameter of -20 nm and a half period of 65 to 80 nm. However, recent vertical platinum-carbon replicas of PHF more closely resemble a thin helical ribbon without constitutive protofilaments. Here we report that native PHF imaged with an atomic force microscope appear as twisted ribbons rather than the generally accepted structure derived from electron microscopic studies. These data imply that the assembly of PHF is not due to the twisting of pair-wise filaments but rather the helical winding of self-associated tau molecules arranged into a flattened structure. Future structural models of PHF should be based on quantitative data obtained from imaging techniques, such as scanning probe microscopy, which do not require harsh specimen preparation procedures. Images Figure 1 PMID:8178938

Twisted ribbon structure of paired helical filaments revealed by atomic force microscopy.

PubMed

Pollanen, M S; Markiewicz, P; Bergeron, C; Goh, M C

1994-05-01

Progressive deposition of phosphorylated tau into the paired helical filaments (PHF) that compose neurofibrillary tangles, dystrophic neurites, and neuropil threads is an obligate feature of Alzheimer's disease. The standard model of PHF structure, derived from electron microscopic studies, suggests that two 8- to 10-nm filaments each composed of three to four protofilaments are wound into a helix with a maximal diameter of -20 nm and a half period of 65 to 80 nm. However, recent vertical platinum-carbon replicas of PHF more closely resemble a thin helical ribbon without constitutive protofilaments. Here we report that native PHF imaged with an atomic force microscope appear as twisted ribbons rather than the generally accepted structure derived from electron microscopic studies. These data imply that the assembly of PHF is not due to the twisting of pair-wise filaments but rather the helical winding of self-associated tau molecules arranged into a flattened structure. Future structural models of PHF should be based on quantitative data obtained from imaging techniques, such as scanning probe microscopy, which do not require harsh specimen preparation procedures.

Structural studies of chromatin and chromosomes. Progress report, March 15--September 15, 1997

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bradbury, E.M.

This study focused on the following: (1) the structure of chromatin and chromosomes by neutron and x-ray scatter and atomic force microscope; (2) the architecture of human sperm and the structure of sperm by atomic force microscopy (AFM); (3) genome-architecture and higher-order structures in human sperm nuclei; and (4) the effects of histone modifications on the structure of nucleosomes by protein DNA crosslinking method.

Predicting Structure-Function Relations and Survival following Surgical and Bronchoscopic Lung Volume Reduction Treatment of Emphysema.

PubMed

Mondoñedo, Jarred R; Suki, Béla

2017-02-01

Lung volume reduction surgery (LVRS) and bronchoscopic lung volume reduction (bLVR) are palliative treatments aimed at reducing hyperinflation in advanced emphysema. Previous work has evaluated functional improvements and survival advantage for these techniques, although their effects on the micromechanical environment in the lung have yet to be determined. Here, we introduce a computational model to simulate a force-based destruction of elastic networks representing emphysema progression, which we use to track the response to lung volume reduction via LVRS and bLVR. We find that (1) LVRS efficacy can be predicted based on pre-surgical network structure; (2) macroscopic functional improvements following bLVR are related to microscopic changes in mechanical force heterogeneity; and (3) both techniques improve aspects of survival and quality of life influenced by lung compliance, albeit while accelerating disease progression. Our model predictions yield unique insights into the microscopic origins underlying emphysema progression before and after lung volume reduction.

Multiparametric, Longitudinal Optical Coherence Tomography Imaging Reveals Acute Injury and Chronic Recovery in Experimental Ischemic Stroke

PubMed Central

Srinivasan, Vivek J.; Mandeville, Emiri T.; Can, Anil; Blasi, Francesco; Climov, Mihail; Daneshmand, Ali; Lee, Jeong Hyun; Yu, Esther; Radhakrishnan, Harsha; Lo, Eng H.; Sakadžić, Sava; Eikermann-Haerter, Katharina; Ayata, Cenk

2013-01-01

Progress in experimental stroke and translational medicine could be accelerated by high-resolution in vivo imaging of disease progression in the mouse cortex. Here, we introduce optical microscopic methods that monitor brain injury progression using intrinsic optical scattering properties of cortical tissue. A multi-parametric Optical Coherence Tomography (OCT) platform for longitudinal imaging of ischemic stroke in mice, through thinned-skull, reinforced cranial window surgical preparations, is described. In the acute stages, the spatiotemporal interplay between hemodynamics and cell viability, a key determinant of pathogenesis, was imaged. In acute stroke, microscopic biomarkers for eventual infarction, including capillary non-perfusion, cerebral blood flow deficiency, altered cellular scattering, and impaired autoregulation of cerebral blood flow, were quantified and correlated with histology. Additionally, longitudinal microscopy revealed remodeling and flow recovery after one week of chronic stroke. Intrinsic scattering properties serve as reporters of acute cellular and vascular injury and recovery in experimental stroke. Multi-parametric OCT represents a robust in vivo imaging platform to comprehensively investigate these properties. PMID:23940761

Predicting Structure-Function Relations and Survival following Surgical and Bronchoscopic Lung Volume Reduction Treatment of Emphysema

PubMed Central

Mondoñedo, Jarred R.

2017-01-01

Lung volume reduction surgery (LVRS) and bronchoscopic lung volume reduction (bLVR) are palliative treatments aimed at reducing hyperinflation in advanced emphysema. Previous work has evaluated functional improvements and survival advantage for these techniques, although their effects on the micromechanical environment in the lung have yet to be determined. Here, we introduce a computational model to simulate a force-based destruction of elastic networks representing emphysema progression, which we use to track the response to lung volume reduction via LVRS and bLVR. We find that (1) LVRS efficacy can be predicted based on pre-surgical network structure; (2) macroscopic functional improvements following bLVR are related to microscopic changes in mechanical force heterogeneity; and (3) both techniques improve aspects of survival and quality of life influenced by lung compliance, albeit while accelerating disease progression. Our model predictions yield unique insights into the microscopic origins underlying emphysema progression before and after lung volume reduction. PMID:28182686

Interactions of Small-Scale Physical Mixing Processes with the Structure, Morphology and Bloom Dynamics and Optics of Non-Spheroid Phytoplankton

DTIC Science & Technology

2001-09-30

microscopic imaging techniques, and microscopic video- cinematography protocols for both phytoplankton and zooplankton for use in current laboratory...phytoplankton, zooplankton and bioluminescence papers, and examined data/figures for layered structures. Imaging and Cinematography : Off-the-shelf...to preview it as a work-in-progress, email me (jrines@gso.uri.edu), and I will provide you with a temporary URL. Imaging and Cinematography

In situ measurements of human articular cartilage stiffness by means of a scanning force microscope

NASA Astrophysics Data System (ADS)

Imer, Raphaël; Akiyama, Terunobu; de Rooij, Nico F.; Stolz, Martin; Aebi, Ueli; Kilger, Robert; Friederich, Niklaus F.; Wirz, Dieter; Daniels, A. U.; Staufer, Urs

2007-03-01

Osteoarthritis is a painful and disabling progressive joint disease, characterized by degradation of articular cartilage. In order to study this disease at early stages, we have miniaturized and integrated a complete scanning force microscope into a standard arthroscopic device fitting through a standard orthopedic canula. This instrument will allow orthopedic surgeons to measure the mechanical properties of articular cartilage at the nanometer and micrometer scale in-vivo during a standard arthroscopy. An orthopedic surgeon assessed the handling of the instrument. First measurements of the elasticity-modulus of human cartilage were recorded in a cadaver knee non minimal invasive. Second, minimally invasive experiments were performed using arthroscopic instruments. Load-displacement curves were successfully recorded.

In-situ deformation studies of an aluminum metal-matrix composite in a scanning electron microscope

NASA Technical Reports Server (NTRS)

Manoharan, M.; Lewandowski, J. J.

1989-01-01

Tensile specimens made of a metal-matrix composite (cast and extruded aluminum alloy-based matrix reinforced with Al2O3 particulate) were tested in situ in a scanning electron microscope equipped with a deformation stage, to directly monitor the crack propagation phenomenon. The in situ SEM observations revealed the presence of microcracks both ahead of and near the crack-tip region. The microcracks were primarily associated with cracks in the alumina particles. The results suggest that a region of intense deformation exists ahead of the crack and corresponds to the region of microcracking. As the crack progresses, a region of plastically deformed material and associated microcracks remains in the wake of the crack.

Natural history of experimental intestinal atresia: morphologic and ultrastructural study.

PubMed

Baglaj, S M; Czernik, J; Kuryszko, J; Kuropka, P

2001-09-01

The aim of this study was to evaluate a natural history of congenital intestinal atresia (IA) in the chick embryo and to assess the type and nature of changes in the intestine at various developmental stages. Chick embryos underwent operative induction of IA on the 12th day of incubation. The procedure consisted of electrocoagulation of the mesenteric vessels supplying a 7- to 8-mm intestinal segment. The embryos were subjected to macroscopic examination, histologic and ultrastructural studies of the preatretic and postatretic bowel using the light microscope, scanning, and transmission electron microscopes. All investigations were performed in an experimental group (operated embryos), in a control group, and in a sham-operated group on the 15th, 17th, 19th, and 21st day of incubation. The original technique of an iatrogenic "vascular event" proved to be effective because IA developed in 96% of embryos surviving the procedure. The affected portion of the bowel underwent progressive necrosis, and signs of bowel obstruction could be observed 48 hours after operation. Cord atresia (type II) developed in 81% of embryos. Histologic investigations showed progressive thinning of mucosa, flattening of mucosal folds, and epithelial detachment within the intestine proximal to atresia. There was only mild hypertrophy of the muscular layers. All these pathomorphologic changes were of rapidly progressive nature until the 17th day of incubation. Later, the rate of distension of preatretic bowel and histologic changes were less. Ultrastructural investigation of the proximal bowel showed progressive flattening of the enterocytes associated with their apical bulging, widening of the intercellular spaces, and microvilli atrophy. Surprisingly, at days 19 and 21 of incubation, signs of induction of adaptive mechanisms with partial restoration of near-normal microvilli pattern were observed. Study of natural history of experimental IA indicates that histologic and ultrastructural lesions of the bowel are of dynamic nature and are not only the effect of pathologic intraluminal pressure. Copyright 2001 by W.B. Saunders Company.

Recent progress in understanding the imaging and metrology using the helium ion microscope

NASA Astrophysics Data System (ADS)

Postek, Michael T.; Vladar, Andras E.; Ming, Bin

2009-05-01

Nanotechnology is pushing imaging and measurement instrument technology to high levels of required performance. As this continues, new barriers confronting innovation in this field are encountered. Particle beam instrument resolution remains one of these barriers. A new tool for imaging and metrology for nanotechnology is the scanning Helium Ion Microscope (HIM). The HIM is a new approach to imaging and metrology for nanotechnology which may be able to push this barrier lower. As a new methodology, it is just beginning to show promise and the number of potentially advantageous applications for nanotechnology and nanometrology has yet to be fully exploited. This presentation will discuss some of the progress made at NIST in collaboration with the manufacturing community in understanding the imaging and metrology for this new technology.

Metallurgical Research Relating to the Development of Metals and Alloys for Use in the High-Temperature Components of Jet-Engines, Gas Turbines and Other Aircraft Propulsion Systems

NASA Technical Reports Server (NTRS)

1948-01-01

Considerable work has been done on report preparation. All items listed in the March program report will be reported during July. Fundamental studies are in progress to establish the fundamental processes by which treatments and composition control properties of commercial alloys at high temperatures. As yet work has been confined to Low-Carbon N155 alloy and progress has been reported twice previously. The work is divided into two sections: studies of solution treated and aged material and studies of rolled structures. Electron microscopic work has been started as an additional technique for the studies. Brief descriptions of experimental techniques used, results, and interpretation of the data obtained since the last report covering this field are summarized below. Since the work outlined is to a large extent still in progress, the discussion given is to be considered tentative and subject to further modification as additional data becomes available.

The Behavior of Matter under Nonequilibrium Conditions: Fundamental Aspects and Applications in Energy-oriented Problems: Progress Report for Period September 1984--November 1987

DOE R&D Accomplishments Database

Prigogine, I.

1987-10-07

This report briefly discusses progress on the following topics: state selection dynamics; polymerization under nonequilibrium conditions; inhomogeneous fluctuations in hydrodynamics and in completely mixed reactors; homoclinic bifurcations and mixed-mode oscillations; intrinsic randomness and spontaneous symmetry breaking in explosive systems; and microscopic means of irreversibility.

Progressive fracture of fiber composites

NASA Technical Reports Server (NTRS)

Irvin, T. B.; Ginty, C. A.

1983-01-01

Refined models and procedures are described for determining progressive composite fracture in graphite/epoxy angleplied laminates. Lewis Research Center capabilities are utilized including the Real Time Ultrasonic C Scan (RUSCAN) experimental facility and the Composite Durability Structural Analysis (CODSTRAN) computer code. The CODSTRAN computer code is used to predict the fracture progression based on composite mechanics, finite element stress analysis, and fracture criteria modules. The RUSCAN facility, CODSTRAN computer code, and scanning electron microscope are used to determine durability and identify failure mechanisms in graphite/epoxy composites.

Cell motility under the microscope: Vorsprung durch Technik.

PubMed

Dunn, Graham A; Jones, Gareth E

2004-08-01

The fashion today is to disparage technology-led research but our view is that cell biologists, in particular, should be proud of their 'progress through technology'. The 'cell theory' itself, arguably the oldest cornerstone in the theoretical foundations of biology, emerged because Hooke, van Leeuwenhoek and others had, more than a century earlier, pioneered the enabling technology--the microscope. We develop this theme with reference to our own field of research: the locomotion of cultured tissue cells.

Recent developments in dimensional nanometrology using AFMs

NASA Astrophysics Data System (ADS)

Yacoot, Andrew; Koenders, Ludger

2011-12-01

Scanning probe microscopes, in particular the atomic force microscope (AFM), have developed into sophisticated instruments that, throughout the world, are no longer used just for imaging, but for quantitative measurements. A role of the national measurement institutes has been to provide traceable metrology for these instruments. This paper presents a brief overview as to how this has been achieved, highlights the future requirements for metrology to support developments in AFM technology and describes work in progress to meet this need.

Quantitatively characterizing the microstructural features of breast ductal carcinoma tissues in different progression stages by Mueller matrix microscope.

PubMed

Dong, Yang; Qi, Ji; He, Honghui; He, Chao; Liu, Shaoxiong; Wu, Jian; Elson, Daniel S; Ma, Hui

2017-08-01

Polarization imaging has been recognized as a potentially powerful technique for probing the microstructural information and optical properties of complex biological specimens. Recently, we have reported a Mueller matrix microscope by adding the polarization state generator and analyzer (PSG and PSA) to a commercial transmission-light microscope, and applied it to differentiate human liver and cervical cancerous tissues with fibrosis. In this paper, we apply the Mueller matrix microscope for quantitative detection of human breast ductal carcinoma samples at different stages. The Mueller matrix polar decomposition and transformation parameters of the breast ductal tissues in different regions and at different stages are calculated and analyzed. For more quantitative comparisons, several widely-used image texture feature parameters are also calculated to characterize the difference in the polarimetric images. The experimental results indicate that the Mueller matrix microscope and the polarization parameters can facilitate the quantitative detection of breast ductal carcinoma tissues at different stages.

Synthesis and characterization of binary titania-silica mixed oxides

NASA Astrophysics Data System (ADS)

Budhi, Sridhar

A series of binary titania-silica mixed oxides were synthesized by the sol-gel method at room temperature. The mixed oxides were prepared that involved the hydrolysis of titanium isopropoxide and tetraethylorthosilicate (TEOS) by co-solvent induced gelation usually in acidic media. The resulting gels were dried, calcined and then characterized by powder X-ray diffractometric studies, nitrogen sorption studies (at 77K), diffuse reflectance spectroscopy, Raman microscopy and transmission electron microscopic studies. The nitrogen sorption studies indicate that the specific surface areas, pore volume, pore diameter and pore size distribution of the mixed oxides were substantially enhanced when non-polar solvents such as toluene, p-xylene or mesitylene were added as co-solvents to the synthesis gel. Transmission electron microscopic (TEM) studies confirm the results obtained from the nitrogen sorption studies. Our results indicate that we can obtain binary metal oxides possessing high surface area and large pore volumes with tunable pore size distribution at room temperature. Photocatalytic evaluation of the mixed oxides is currently in progress.

Surgical Tooth Implants, Combat and Field.

DTIC Science & Technology

1984-07-15

and identify by block number) --- This Annual Report summarizes progress to date on a long-term implant study of a serrated ceramic dental implant...upper two parts of the implant, post and core and crown, are conventional metaT materials. A series of graded dental implants have been produced to...throughout the experimental period. Periodic radio- graphic analyses of dental implants verify this observation. Gross and microscopic patho- logic analyses

Progress towards measurement of entanglement entropy dynamics in one-dimensional interacting systems in the presence of disorder

NASA Astrophysics Data System (ADS)

Lukin, Alexander; Tai, M. Eric; Rispoli, Matthew; Schittko, Robert; Menke, Tim; Kaufman, Adam; Greiner, Markus

2017-04-01

Many-body localized states appear at odds with thermalization as they preserve the memory of their initial state. This behavior has drawn significant theoretical and experimental attention in recent years. Real space localization has been observed on various platforms and under a number of experimental conditions, both with and without interactions. However, the characteristic logarithmic growth of entanglement entropy, which distinguishes the many-body localized state from the non-interacting Anderson localized state, has only been studied in numerics and has yet to be investigated experimentally. We are working towards the phenomenon of localization in one dimensional, interacting Bose-Hubbard system using a quantum gas microscope. With site-resolved addressing and readout, our microscope provides full control over the studied system, in particular it allows us to add disorder into our system using a Fourier plane hologram. This gives us access to both local observables, such as the occupation of individual lattice sites, as well as the entanglement entropy. I will present our progress towards measuring the dependence of the entanglement entropy grows on the disorder strength and interactions in our system. National Science Foundation, Gordon and Betty Moore Foundation's EPiQS Initiative, Air Force Office of Scientific Research MURI program, NSF Graduate Research Fellowship Program (MNR).

Microscopic Scale Simulation of the Ablation of Fibrous Materials

NASA Technical Reports Server (NTRS)

Lachaud, Jean Romain; Mansour, Nagi N.

2010-01-01

Ablation by oxidation of carbon-fiber preforms impregnated in carbonized phenolic matrix is modeled at microscopic scale. Direct numerical simulations show that the carbonized phenolic matrix ablates in volume leaving the carbon fibers exposed. This is due to the fact that the reactivity of carbonized phenolic is higher than the reactivity of carbon fibers. After the matrix is depleted, the fibers ablate showing progressive reduction of their diameter. The overall material recession occurs when the fibers are consumed. Two materials with the same carbon-fiber preform, density and chemical composition, but with different matrix distributions are studied. These studies show that at moderate temperatures (< 1000 K) the microstructure of the material influences its recession rate; a fact that is not captured by current models that are based on chemical composition only. Surprisingly, the response of these impregnated-fiber materials is weakly dependent on the microstructure at very high temperatures (e.g., Stardust peak heating conditions: 3360K).

Special section introduction on MicroMars to MegaMars

USGS Publications Warehouse

Bridges, Nathan T.; Dundas, Colin M.; Edgar, Lauren

2016-01-01

The study of Earth's surface and atmosphere evolved from local investigations to the incorporation of remote sensing on a global scale. The study of Mars has followed the opposite progression, beginning with telescopic observations, followed by flyby and orbital missions, landers, and finally rover missions in the last ∼20 years. This varied fleet of spacecraft (seven of which are currently operating as of this writing) provides a rich variety of datasets at spatial scales ranging from microscopic images to synoptic orbital remote sensing.

Microscopic progression in the free radical addition reaction: modeling, geometry, energy, and kinetics.

PubMed

Zhang, Yun; Huang, Hong; Liang, Zhiling; Liu, Houhe; Yi, Ling; Zhang, Jinhong; Zhang, Zhiqiang; Zhong, Cheng; Huang, Yugang; Ye, Guodong

2017-03-01

The free radical addition reaction is very important in UV curing. The benzoyl radical is the most commonly observed radical. In the addition process, the benzoyl radical adds to an acrylate monomer, forming a primary radical that has great value for subsequent research. In this article, a quantum chemical method was used to study the microscopic progression from the reactive complex to the saddle point. The reactions of three monomers (amylene, allyl methyl ether and methyl acrylate) with a benzoyl radical were evaluated in terms of geometry and energy. The results were also interpreted with an expanded version of the Polanyi rules and the interaction/deformation theory. The deformation energy of methyl acrylate was found to be the smallest, and the bond formation index showed that the transition state in the methyl acrylate system forms early, and can easily reach the saddle point. The activity of the monomer was ascertained by charge analysis and was further confirmed by the reaction rate. Mayer bond order curves depicted the constantly changing chemical bonds during formation and dissociation. Reduced density gradient analysis showed a weak interaction between the monomer and the benzoyl radical.

Evanescent-Wave Filtering in Images Using Remote Terahertz Structured Illumination

NASA Astrophysics Data System (ADS)

Flammini, M.; Pontecorvo, E.; Giliberti, V.; Rizza, C.; Ciattoni, A.; Ortolani, M.; DelRe, E.

2017-11-01

Imaging with structured illumination allows for the retrieval of subwavelength features of an object by conversion of evanescent waves into propagating waves. In conditions in which the object plane and the structured-illumination plane do not coincide, this conversion process is subject to progressive filtering of the components with high spatial frequency when the distance between the two planes increases, until the diffraction-limited lateral resolution is restored when the distance exceeds the extension of evanescent waves. We study the progressive filtering of evanescent waves by developing a remote super-resolution terahertz imaging system operating at a wavelength λ =1.00 mm , based on a freestanding knife edge and a reflective confocal terahertz microscope. In the images recorded with increasing knife-edge-to-object-plane distance, we observe the transition from a super-resolution of λ /17 ≃60 μ m to the diffraction-limited lateral resolution of Δ x ≃λ expected for our confocal microscope. The extreme nonparaxial conditions are analyzed in detail, exploiting the fact that, in the terahertz frequency range, the knife edge can be positioned at a variable subwavelength distance from the object plane. Electromagnetic simulations of radiation scattering by the knife edge reproduce the experimental super-resolution achieved.

Paget's disease of the vulva: a clinicopathologic institutional review.

PubMed

Mendivil, Alberto A; Abaid, Lisa; Epstein, Howard D; Rettenmaier, Mark A; Brown, John V; Micha, John P; Wabe, Marie A; Goldstein, Bram H

2012-12-01

The aim of this study was to assess the clinicopathologic characteristics of patients with Paget's disease of the vulva who were treated by our gynecologic oncology service between 1985 and 2010. Vulvar Paget's disease patient demographics, pathologic diagnosis, treatment and follow-up data were reviewed over a 25-year period. The vulvar Paget's disease patients were primarily (62.5%) treated with a partial simple vulvectomy. Three patients had a history of malignancy, although none of them was intercurrent. Eleven patients had microscopically positive margins, 5 of whom developed progressive disease. Conversely, 5 patients had negative margins, of whom 4 had recurrent disease. There was a significant relationship between the presence of invasive disease and patient progression-free interval (PFI) (p = 0.007), but margin status and lesion size did not correlate with PFI (p > 0.05). Median patient PFI and follow-up was 30 and 53 months, respectively. We found a significant relationship between the presence of invasive disease and patient PFI in vulvar Paget's disease although the presence of microscopic positive margins and lesion size were not prognostic indicators. In patients with high risk factors, prolonged surveillance should be considered an essential component of optimal patient management.

Design of a normal incidence multilayer imaging x-ray microscope.

PubMed

Shealy, D L; Gabardi, D R; Hoover, R B; Walker, A B; Lindblom, J F; Barbee, T W

1989-01-01

Normal incidence multilayer Cassegrain x-ray telescopes were flown on the Stanford/MSFC Rocket X-Ray Spectroheliograph. These instruments produced high spatial resolution images of the Sun and conclusively demonstrated that doubly reflecting multilayer x-ray optical systems are feasible. The images indicated that aplanatic imaging soft x-ray /EUV microscopes should be achievable using multilayer optics technology. We have designed a doubly reflecting normal incidence multilayer imaging x-ray microscope based on the Schwarzschild configuration. The Schwarzschild microscope utilizes two spherical mirrors with concentric radii of curvature which are chosen such that the third-order spherical aberration and coma are minimized. We discuss the design of the microscope and the results of the optical system ray trace analysis which indicates that diffraction-limited performance with 600 Å spatial resolution should be obtainable over a 1 mm field of view at a wavelength of 100 Å. Fabrication of several imaging soft x-ray microscopes based upon these designs, for use in conjunction with x-ray telescopes and laser fusion research, is now in progress. High resolution aplanatic imaging x-ray microscopes using normal incidence multilayer x-ray mirrors should have many important applications in advanced x-ray astronomical instrumentation, x-ray lithography, biological, biomedical, metallurgical, and laser fusion research.

Ceroid-lipofuscinosis in border collie dogs.

PubMed

Taylor, R M; Farrow, B R

1988-01-01

Five Border Collie dogs with ceroid-lipofuscinosis developed progressive neurological disease between 18 and 22 months of age. These dogs had behavioural abnormalities, gait and visual deficits and became progressively demented. All dogs examined had common ancestors. Light microscopic examination of tissues demonstrated extensive accumulation of granular, sudan black-staining autofluorescent material in the cytoplasm of neurones, retinal ganglion cells and some visceral cells. At ultrastructural examination inclusions of variable morphology were observed.

Recent progress in the imaging of soil processes at the microscopic scale, and a look ahead

NASA Astrophysics Data System (ADS)

Garnier, Patricia; Baveye, Philippe C.; Pot, Valérie; Monga, Olivier; Portell, Xavier

2016-04-01

Over the last few years, tremendous progress has been achieved in the visualization of soil structures at the microscopic scale. Computed tomography, based on synchrotron X-ray beams or table-top equipment, allows the visualization of pore geometry at micrometric resolution. Chemical and microbiological information obtainable in 2D cuts through soils can now be interpolated, with the support of CT-data, to produce 3-dimensional maps. In parallel with these analytical advances, significant progress has also been achieved in the computer simulation and visualization of a range of physical, chemical, and microbiological processes taking place in soil pores. In terms of water distribution and transport in soils, for example, the use of Lattice-Boltzmann models as well as models based on geometric primitives has been shown recently to reproduce very faithfully observations made with synchrotron X-ray tomography. Coupling of these models with fungal and bacterial growth models allows the description of a range of microbiologically-mediated processes of great importance at the moment, for example in terms of carbon sequestration. In this talk, we shall review progress achieved to date in this field, indicate where questions remain unanswered, and point out areas where further advances are expected in the next few years.

Sodium Fluorescein-Guided Resection under the YELLOW 560 nm Surgical Microscope Filter in Malignant Gliomas: Our First 38 Cases Experience.

PubMed

Zhang, Ningning; Tian, Hailong; Huang, Dezhang; Meng, Xianbing; Guo, Wenqiang; Wang, Chaochao; Yin, Xin; Zhang, Hongying; Jiang, Bin; He, Zheng; Wang, Zhigang

2017-01-01

Sodium fluorescein (FL) had been safely used in fluorescence-guided microsurgery for imaging various brain tumors. Under the YELLOW 560 nm surgical microscope filter, low-dose FL as a fluorescent dye helps in visualization. Our study investigated the safety and efficacy of this innovative technique in malignant glioma (MG) patients. 38 patients suffering from MGs confirmed by pathology underwent FL-guided resection under YELLOW 560 nm surgical microscope filter. We retrospectively analyzed the clinical characters, microsurgery procedure, extent of resection, pathology of MGs, progression-free survival (PFS), and overall survival (OS). Thirty-eight patients had MGs (10 WHO grade III, 28 WHO grade IV). With YELLOW 560 nm surgical microscope filter combined with neuronavigation, sodium fluorescein-guided gross total resection (GTR) was achieved in 35 (92.1%) patients and subtotal resection in 3 (7.69%). The sensitivity and specificity of FL were 94.4% and 88.6% regardless of radiographic localization. Intraoperatively, 10 biopsies (10/28 FL[+]) showed "low" or "high" fluorescence in non-contrast-enhancement region and are also confirmed by pathology. Our data showed 6-month PFS of 92.3% and median survival of 11 months. FL-guided resection of MGs under the YELLOW 560 nm surgical microscope filter combined with neuronavigation was safe and effective, especially in non-contrast-MRI regions. It is feasible for improving the extent of resection in MGs especially during emergency cases.

Vibrational spectroscopy in the electron microscope.

PubMed

Krivanek, Ondrej L; Lovejoy, Tracy C; Dellby, Niklas; Aoki, Toshihiro; Carpenter, R W; Rez, Peter; Soignard, Emmanuel; Zhu, Jiangtao; Batson, Philip E; Lagos, Maureen J; Egerton, Ray F; Crozier, Peter A

2014-10-09

Vibrational spectroscopies using infrared radiation, Raman scattering, neutrons, low-energy electrons and inelastic electron tunnelling are powerful techniques that can analyse bonding arrangements, identify chemical compounds and probe many other important properties of materials. The spatial resolution of these spectroscopies is typically one micrometre or more, although it can reach a few tens of nanometres or even a few ångströms when enhanced by the presence of a sharp metallic tip. If vibrational spectroscopy could be combined with the spatial resolution and flexibility of the transmission electron microscope, it would open up the study of vibrational modes in many different types of nanostructures. Unfortunately, the energy resolution of electron energy loss spectroscopy performed in the electron microscope has until now been too poor to allow such a combination. Recent developments that have improved the attainable energy resolution of electron energy loss spectroscopy in a scanning transmission electron microscope to around ten millielectronvolts now allow vibrational spectroscopy to be carried out in the electron microscope. Here we describe the innovations responsible for the progress, and present examples of applications in inorganic and organic materials, including the detection of hydrogen. We also demonstrate that the vibrational signal has both high- and low-spatial-resolution components, that the first component can be used to map vibrational features at nanometre-level resolution, and that the second component can be used for analysis carried out with the beam positioned just outside the sample--that is, for 'aloof' spectroscopy that largely avoids radiation damage.

Understanding Imaging and Metrology with the Helium Ion Microscope

NASA Astrophysics Data System (ADS)

Postek, Michael T.; Vladár, András E.; Ming, Bin

2009-09-01

One barrier to innovation confronting all phases of nanotechnology is the lack of accurate metrology for the characterization of nanomaterials. Ultra-high resolution microscopy is a key technology needed to achieve this goal. But, current microscope technology is being pushed to its limits. The scanning and transmission electron microscopes have incrementally improved in performance and other scanned probe technologies such as atomic force microscopy, scanning tunneling microscopy and focused ion beam microscopes have all been applied to nanotechnology with various levels of success. A relatively new tool for nanotechnology is the scanning helium ion microscope (HIM). The HIM is a new complementary imaging and metrology technology for nanotechnology which may be able to push the current resolution barrier lower. But, successful imaging and metrology with this instrument entails new ion beam/specimen interaction physics which must be fully understood. As a new methodology, HIM is beginning to show promise and the abundance of potentially advantageous applications for nanotechnology have yet to be fully exploited. This presentation will discuss some of the progress made at NIST in understanding the science behind this new technique.

User-independent EBSD parameters to study the progress of recovery and recrystallization in Cu-Zn alloy during in situ heating.

PubMed

Sharma, N K; Shekhar, S

2016-12-01

Microstructural evolution of cold-rolled Cu-5%Zn alloy during in situ heating inside field-emission scanning electron microscope was utilized to obtain user-independent parameters in order to trace the progress of static recovery and recrystallization. Electron back-scattered diffraction (EBSD)-based orientation imaging microscopy was used to obtain micrographs at various stages of in situ heating. It is shown that unlike the pre-existing methods, additional EBSD-based parameter can be used to trace the progress of recovery and recrystallization, which is not dependent on user input and hence less prone to error. True strain of 0.3 was imposed during cold rolling of alloy sample. Rolled sample was subjected to in situ heating from room temperature to 500°C (∼0.58 Tm) with soaking time of 10 min, at each of the intermediate temperatures viz. 100, 200, 300, 400 and 450°C. After reaching 500°C, the sample was kept at this temperature for a maximum duration of around 15 h. The sample showed clear signs of recovery for temperature up to 450°C, and at 500°C, recrystallization started to take place. Recrystallization kinetics was moderate, and full recrystallization was achieved in approximately 120 min. We found that EBSD parameter, namely, band contrast intensity can be used as an extra handle to map out the progress of recrystallization occurring in the sample. By contrast, mean angular deviation can be used to understand the evolution of recovery in samples. The parameters mentioned in the current study, unlike other pre-existing methods, can also be used for mapping local microstructural transformations due to recovery and recrystallization. We discuss the benefits and limitations in using these additional handles in understanding the changes taking place in the material during in situ heating. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

Obtaining macroscopic quantities for the contact line problem from Density Functional Theory using asymptotic methods

NASA Astrophysics Data System (ADS)

Sibley, David; Nold, Andreas; Kalliadasis, Serafim

2015-11-01

Density Functional Theory (DFT), a statistical mechanics of fluids approach, captures microscopic details of the fluid density structure in the vicinity of contact lines, as seen in computations in our recent study. Contact lines describe the location where interfaces between two fluids meet solid substrates, and have stimulated a wealth of research due to both their ubiquity in nature and technological applications and also due to their rich multiscale behaviour. Whilst progress can be made computationally to capture the microscopic to mesoscopic structure from DFT, complete analytical results to fully bridge to the macroscale are lacking. In this work, we describe our efforts to bring asymptotic methods to DFT to obtain results for contact angles and other macroscopic quantities in various parameter regimes. We acknowledge financial support from European Research Council via Advanced Grant No. 247031.

Software for imaging phase-shift interference microscope

NASA Astrophysics Data System (ADS)

Malinovski, I.; França, R. S.; Couceiro, I. B.

2018-03-01

In recent years absolute interference microscope was created at National Metrology Institute of Brazil (INMETRO). The instrument by principle of operation is imaging phase-shifting interferometer (PSI) equipped with two stabilized lasers of different colour as traceable reference wavelength sources. We report here some progress in development of the software for this instrument. The status of undergoing internal validation and verification of the software is also reported. In contrast with standard PSI method, different methodology of phase evaluation is applied. Therefore, instrument specific procedures for software validation and verification are adapted and discussed.

Isolated benign cerebral vasculitis or migrainous vasospasm?

PubMed Central

Serdaru, M; Chiras, J; Cujas, M; Lhermitte, F

1984-01-01

A 39-year-old woman experienced severe headache, epilepsy and rapidly progressive aphasia and hemianopia. Carotid angiograms displayed segmentary narrowing of intracranial arteries as previously described in benign cerebral vasculitis. Her superficial temporal artery was also involved, allowing a biopsy of the abnormal part of the vessel. Microscopical study of this artery was normal. A second carotid angiogram, 14 days later, showed normal intracranial arteries. These findings suggest arterial spasm rather than distal arteritis. Images PMID:6693916

Characterizing Fibrosis in Mouse Kidney using Label Free Fluorescence Lifetime and Second Harmonic Generation Imaging Microscopy in Unilateral Ureteral Obstruction Model

PubMed Central

Ranjit, Suman; Dobrinskikh, Evgenia; Montford, John; Dvornikov, Alexander; Lehman, Allison; Orlicky, David J.; Nemenoff, Raphael; Gratton, Enrico; Levi, Moshe; Furgeson, Seth

2017-01-01

All forms of progressive renal diseases develop a final pathway of tubulointerstitial fibrosis and glomerulosclerosis. Renal fibrosis is usually quantified using histological staining, a process that is time-consuming and pathologist dependent. The work described here shows the development of a fast and operator-independent method to measure fibrosis. To study renal fibrosis, the unilateral ureteral obstruction (UUO) model was chosen. Mice develop a time-dependent increase in obstructed kidneys; contralateral kidneys are used as controls. After UUO, kidneys were analyzed at three time points: 7 days, 14 days, and 21 days. Fibrosis was investigated using FLIM (Fluorescence Lifetime Imaging) and SHG (Second Harmonic Generation) in the deep tissue imaging microscope called DIVER (Deep Imaging via Enhanced photon Recovery). This microscope was developed for deep tissue and SHG and THG (Third Harmonic Generation) imaging and has extraordinary sensitivity towards harmonic generation. SHG data suggests the presence of more fibrillar collagen in the diseased kidneys. The combinations of short wavelength FLIM and SHG analysis results in a robust analysis procedure independent of observer interpretation and let us create a criterion to quantify the extent of fibrosis directly from the image. The progression of fibrosis in UUO model has been studied using this new FLIM-SHG technique and it shows remarkable improvement in quantification of fibrosis compared to standard histological techniques. PMID:27555119

Biophysics of cancer progression and high-throughput mechanical characterization of biomaterials

NASA Astrophysics Data System (ADS)

Osborne, Lukas Dylan

Cancer metastasis involves a series of events known as the metastatic cascade. In this complex progression, cancer cells detach from the primary tumor, invade the surrounding stromal space, transmigrate the vascular system, and establish secondary tumors at distal sites. Specific mechanical phenotypes are likely adopted to enable cells to successfully navigate the mechanical environments encountered during metastasis. To examine the role of cell mechanics in cancer progression, I employed force-consistent biophysical and biochemical assays to characterize the mechanistic links between stiffness, stiffness response and cell invasion during the epithelial to mesenchymal transition (EMT). EMT is an essential physiological process, whose abnormal reactivation has been implicated in the detachment of cancer cells from epithelial tissue and their subsequent invasion into stromal tissue. I demonstrate that epithelial-state cells respond to force by evoking a stiffening response, and that after EMT, mesenchymal-state cells have reduced stiffness but also lose the ability to increase their stiffness in response to force. Using loss and gain of function studies, two proteins are established as functional connections between attenuated stiffness and stiffness response and the increased invasion capacity acquired after EMT. To enable larger scale assays to more fully explore the connection between biomechanics and cancer, I discuss the development of an automated array high throughput (AHT) microscope. The AHT system is shown to implement passive microbead rheology to accurately characterize the mechanical properties of biomaterials. Compared to manually performed mechanical characterizations, the AHT system executes experiments in two orders of magnitude less time. Finally, I use the AHT microscope to study the effect of gain of function oncogenic molecules on cell stiffness. I find evidence that our assay can identify alterations in cell stiffness due to constitutive activation of cancer pathways.

From microscopic to astronomic, the legacy of Carl Zeiss.

PubMed

Louw, Deon F; Sutherland, Garnette R; Schulder, Michael

2003-03-01

IN 1846, CARL ZEISS established a workshop to make lenses for microscopes, cameras, binoculars, and astronomical observatories. He was a master craftsman and was intolerant of any flaw, destroying microscopes with only minor inaccuracies. His relentless pursuit of perfection brought him into contact with a brilliant physicist, Ernst Abbe. Zeiss combined Abbe's new optical laws with his own technical skills; together, they created a colossus. Their company came to be known not only for exquisite technical standards but also for labor relations that were and remain progressive. The development of microneurosurgery was aided by the active participation of Carl Zeiss, Inc. The history of this company provides a lesson in the power of entrepreneurship and the benefits to humanity that can accrue from a fruitful partnership between medical science and industry.

Imaging tumor microscopic viscosity in vivo using molecular rotors

PubMed Central

Shimolina, Lyubov’ E.; Izquierdo, Maria Angeles; López-Duarte, Ismael; Bull, James A.; Shirmanova, Marina V.; Klapshina, Larisa G.; Zagaynova, Elena V.; Kuimova, Marina K.

2017-01-01

The microscopic viscosity plays an essential role in cellular biophysics by controlling the rates of diffusion and bimolecular reactions within the cell interior. While several approaches have emerged that have allowed the measurement of viscosity and diffusion on a single cell level in vitro, the in vivo viscosity monitoring has not yet been realized. Here we report the use of fluorescent molecular rotors in combination with Fluorescence Lifetime Imaging Microscopy (FLIM) to image microscopic viscosity in vivo, both on a single cell level and in connecting tissues of subcutaneous tumors in mice. We find that viscosities recorded from single tumor cells in vivo correlate well with the in vitro values from the same cancer cell line. Importantly, our new method allows both imaging and dynamic monitoring of viscosity changes in real time in live animals and thus it is particularly suitable for diagnostics and monitoring of the progress of treatments that might be accompanied by changes in microscopic viscosity. PMID:28134273

EDITORIAL: Nature's building blocks Nature's building blocks

NASA Astrophysics Data System (ADS)

Engel, Andreas

2009-10-01

The scanning tunnelling microscope (STM), invented by Gerd Binnig and Heinrich Rohrer in the early 1980s in the IBM Laboratory in Zurich, and the atomic force microscope (AFM) that followed shortly afterwards, were key developments that initiated a new era in scientific research: nanotechnology. These and related scanning probe microscopes have become fruitful tools in the study of cells, supramolecular assemblies and single biomolecules, as well as other nanoscale structures. In particular, the ability to investigate living matter in native environments made possible by atomic force microscopy, has allowed pronounced progress in biological research. The journal Nanotechnology was the first to serve as a publication platform for this rapidly developing field of science. The journal celebrates its 20th volume with this special issue, which presents a collection of original research articles in various fields of science, but all with the common feature that the structures, processes and functions all take place at the nanometre scale. Scanning probe microscopes are constantly being devised with increasingly sophisticated sensing and actuating features that optimize their performance. However, while these tools continue to provide impressive and informative images of nanoscale systems and allow single molecules to be manipulated with increasing dexterity, a wider field of research activity stimulated either by or for biology has emerged. The unique properties of matter at the nanoscale, such as localized surface plasmons supported by nanostructures, have been exploited in sensors with unprecedented sensitivity. Nanostructures have also found a profitable role in the encapsulation of molecules for 'smart' drug delivery. The potential application of DNA in the self-assembly of nanostructures guided by molecular recognition is another rapidly advancing area of research. In this issue a group of researchers in Germany report how the addition of copper ions can promote the stability of modified double-stranded DNA. They use scanning force microscope observations to provide insights into the energy landscape as DNA complexes form. This research provides just one example of how developments on biological systems are being applied to research across the spectrum of disciplines. This 20th volume special issue provides a snapshot of current state-of-the-art research activity in various areas of nanotechnology, and highlights the breadth and range of research progressing in this field. The developments reported here highlight the continued prominence of biology-related research and promise a bright future for nanotechnology.

Sodium Fluorescein-Guided Resection under the YELLOW 560 nm Surgical Microscope Filter in Malignant Gliomas: Our First 38 Cases Experience

PubMed Central

Tian, Hailong; Huang, Dezhang; Meng, Xianbing; Guo, Wenqiang; Wang, Chaochao; Yin, Xin; Zhang, Hongying; Jiang, Bin; He, Zheng

2017-01-01

Objective Sodium fluorescein (FL) had been safely used in fluorescence-guided microsurgery for imaging various brain tumors. Under the YELLOW 560 nm surgical microscope filter, low-dose FL as a fluorescent dye helps in visualization. Our study investigated the safety and efficacy of this innovative technique in malignant glioma (MG) patients. Patients and Method 38 patients suffering from MGs confirmed by pathology underwent FL-guided resection under YELLOW 560 nm surgical microscope filter. We retrospectively analyzed the clinical characters, microsurgery procedure, extent of resection, pathology of MGs, progression-free survival (PFS), and overall survival (OS). Results Thirty-eight patients had MGs (10 WHO grade III, 28 WHO grade IV). With YELLOW 560 nm surgical microscope filter combined with neuronavigation, sodium fluorescein-guided gross total resection (GTR) was achieved in 35 (92.1%) patients and subtotal resection in 3 (7.69%). The sensitivity and specificity of FL were 94.4% and 88.6% regardless of radiographic localization. Intraoperatively, 10 biopsies (10/28 FL[+]) showed “low” or “high” fluorescence in non-contrast-enhancement region and are also confirmed by pathology. Our data showed 6-month PFS of 92.3% and median survival of 11 months. Conclusion FL-guided resection of MGs under the YELLOW 560 nm surgical microscope filter combined with neuronavigation was safe and effective, especially in non-contrast-MRI regions. It is feasible for improving the extent of resection in MGs especially during emergency cases. PMID:29124069

Time-dependent entropy evolution in microscopic and macroscopic electromagnetic relaxation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker-Jarvis, James

This paper is a study of entropy and its evolution in the time and frequency domains upon application of electromagnetic fields to materials. An understanding of entropy and its evolution in electromagnetic interactions bridges the boundaries between electromagnetism and thermodynamics. The approach used here is a Liouville-based statistical-mechanical theory. I show that the microscopic entropy is reversible and the macroscopic entropy satisfies an H theorem. The spectral entropy development can be very useful for studying the frequency response of materials. Using a projection-operator based nonequilibrium entropy, different equations are derived for the entropy and entropy production and are applied tomore » the polarization, magnetization, and macroscopic fields. I begin by proving an exact H theorem for the entropy, progress to application of time-dependent entropy in electromagnetics, and then apply the theory to relevant applications in electromagnetics. The paper concludes with a discussion of the relationship of the frequency-domain form of the entropy to the permittivity, permeability, and impedance.« less

In vitro characterizations of mesoporous hydroxyapatite as a controlled release delivery device for VEGF in orthopedic applications.

PubMed

Poh, Chye Khoon; Ng, Suxiu; Lim, Tee Yong; Tan, Hark Chuan; Loo, Joachim; Wang, Wilson

2012-11-01

Following bone implant surgery, prolonged ischemic conditions at the implant site often result in postsurgical complications like failure of osseointegration at the bone-implant interface which can lead to implant failure. Thus, restoration of the vascular supply is paramount to the proper development of the bone. High surface area mesostructured materials have been shown to be attractive candidates for bone regeneration to enhance cell adhesion and cell proliferation. This study uses hydroxyapatite, a naturally occurring mineral in the bone, fabricated to a range of suitable pore sizes, infused with vascular endothelial growth factor (VEGF), to be progressively released to stimulate revascularization. In this study, several characterizations including nitrogen adsorption analysis, Fourier-transformed infrared spectroscopy, X-ray diffraction, field emission scanning electron microscope, and transmission electron microscope were used to evaluate the synthesized mesoporous hydroxyapatite (MHA). The results showed that MHA can gradually release VEGF for enhancing revascularization, which is beneficial for orthopedic applications. Copyright © 2012 Wiley Periodicals, Inc.

Biological Effects of Laser Radiation. Volume I. Review of the Literature on Biological Effects of Laser Radiation-to 1965.

DTIC Science & Technology

1978-10-17

because of the rapid progress made in laser technology to date. The use of the Laser Microprobe in spectrochemical analysis of the elements is based on...spectroscopy to vaporize microscopic amounts of samples for elemental analysis . On the other hand, the intense, highly monochromatic laser beam is being...employed as a light source for Raman spectroscopy to study molecular structure. These two uses of lasers in spectroscopic analysis have been sucessful

GENOA-PFA: Progressive Fracture in Composites Simulated Computationally

NASA Technical Reports Server (NTRS)

Murthy, Pappu L. N.

2000-01-01

GENOA-PFA is a commercial version of the Composite Durability Structural Analysis (CODSTRAN) computer program that simulates the progression of damage ultimately leading to fracture in polymer-matrix-composite (PMC) material structures under various loading and environmental conditions. GENOA-PFA offers several capabilities not available in other programs developed for this purpose, making it preferable for use in analyzing the durability and damage tolerance of complex PMC structures in which the fiber reinforcements occur in two- and three-dimensional weaves and braids. GENOA-PFA implements a progressive-fracture methodology based on the idea that a structure fails when flaws that may initially be small (even microscopic) grow and/or coalesce to a critical dimension where the structure no longer has an adequate safety margin to avoid catastrophic global fracture. Damage is considered to progress through five stages: (1) initiation, (2) growth, (3) accumulation (coalescence of propagating flaws), (4) stable propagation (up to the critical dimension), and (5) unstable or very rapid propagation (beyond the critical dimension) to catastrophic failure. The computational simulation of progressive failure involves formal procedures for identifying the five different stages of damage and for relating the amount of damage at each stage to the overall behavior of the deteriorating structure. In GENOA-PFA, mathematical modeling of the composite physical behavior involves an integration of simulations at multiple, hierarchical scales ranging from the macroscopic (lamina, laminate, and structure) to the microscopic (fiber, matrix, and fiber/matrix interface), as shown in the figure. The code includes algorithms to simulate the progression of damage from various source defects, including (1) through-the-thickness cracks and (2) voids with edge, pocket, internal, or mixed-mode delaminations.

Wear effects on microscopic morphology and hyaluronan uptake in siloxane-hydrogel contact lenses.

PubMed

Tavazzi, Silvia; Tonveronachi, Martina; Fagnola, Matteo; Cozza, Federica; Ferraro, Lorenzo; Borghesi, Alessandro; Ascagni, Miriam; Farris, Stefano

2015-07-01

The purpose of this study was a comparison between new and worn siloxane-hydrogel contact lenses in terms of microscopic structure, surface morphology, and loading of hyaluronan. The analyses were performed by scanning electron microscopy, with the support of the freeze-drying technique, and by fluorescence confocal microscopy. Along the depth profile of new lenses, a thin porous top layer was observed, which corresponds to the region of hyaluronan penetration inside well-defined channels. The time evolution was followed from one day to two weeks of daily wear, when a completely different scenario was found. Clear experimental evidence of a buggy surface was observed with several crests and regions of swelling, which could be filled by the hyaluronan solution. The modifications are attributed to the progressive relaxation of the structure of the polymeric network. © 2014 Wiley Periodicals, Inc.

Potential Engineering of Fermi-Hubbard Systems using a Quantum Gas Microscope

NASA Astrophysics Data System (ADS)

Ji, Geoffrey; Mazurenko, Anton; Chiu, Christie; Parsons, Maxwell; Kanász-Nagy, Márton; Schmidt, Richard; Grusdt, Fabian; Demler, Eugene; Greif, Daniel; Greiner, Markus

2017-04-01

Arbitrary control of optical potentials has emerged as an important tool in manipulating ultracold atomic systems, especially when combined with the single-site addressing afforded by quantum gas microscopy. Already, experiments have used digital micromirror devices (DMDs) to initialize and control ultracold atomic systems in the context of studying quantum walks, quantum thermalization, and many-body localization. Here, we report on progress in using a DMD located in the image plane of a quantum gas microscope to explore static and dynamic properties of a 2D Fermi-Hubbard system. By projecting a large, ring-shaped anti-confining potential, we demonstrate entropy redistribution and controlled doping of the system. Moreover, we use the DMD to prepare localized holes, which upon release interact with and disrupt the surrounding spin environment. These techniques pave the way for controlled investigations of dynamics in the low-temperature phases of the Hubbard model.

Molecular Imaging of Apoptosis: From Micro to Macro

PubMed Central

Zeng, Wenbin; Wang, Xiaobo; Xu, Pengfei; Liu, Gang; Eden, Henry S.; Chen, Xiaoyuan

2015-01-01

Apoptosis, or programmed cell death, is involved in numerous human conditions including neurodegenerative diseases, ischemic damage, autoimmune disorders and many types of cancer, and is often confused with other types of cell death. Therefore strategies that enable visualized detection of apoptosis would be of enormous benefit in the clinic for diagnosis, patient management, and development of new therapies. In recent years, improved understanding of the apoptotic machinery and progress in imaging modalities have provided opportunities for researchers to formulate microscopic and macroscopic imaging strategies based on well-defined molecular markers and/or physiological features. Correspondingly, a large collection of apoptosis imaging probes and approaches have been documented in preclinical and clinical studies. In this review, we mainly discuss microscopic imaging assays and macroscopic imaging probes, ranging in complexity from simple attachments of reporter moieties to proteins that interact with apoptotic biomarkers, to rationally designed probes that target biochemical changes. Their clinical translation will also be our focus. PMID:25825597

Multisite two-photon imaging of neurons on multielectrode arrays

NASA Astrophysics Data System (ADS)

Potter, Steve M.; Lukina, Natalia; Longmuir, Kenneth J.; Wu, Yan

2001-04-01

We wish to understand how neural systems store, recall, and process information. We are using cultured networks of cortical neurons grown on microelectrode arrays as a model system for studying the emergent properties of ensembles of living neurons. We have developed a 2-way communication interface between the cultured network and a computer- generated animal, the Neurally Controlled Animat. Neural activity is used to control the behavior of the Animat, and 2- photon time-lapse imaging is carried out in order to observe the morphological changes that might underlie changes in neural processing. The 2-photon microscope is ideal for repeated imaging over hours or days, with submicron resolution and little photodamage. We have designed a computer-controlled microscope stage that allows imaging several locations in sequence, in order to collect more image data. For the latest progress, see: http://www.caltech.edu/~pinelab/PotterGroup.htm.

IMAGING SOIL BACTERIA IN AN ENVIRONMENTAL SCANNING ELECTRON MICROSCOPE. (R827133)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Naulleau, Patrick; Mochi, Iacopo; Goldberg, Kenneth A.

Defect free masks remain one of the most significant challenges facing the commercialization of extreme ultraviolet (EUV) lithography. Progress on this front requires high-performance wavelength-specific metrology of EUV masks, including high-resolution and aerial-image microscopy performed near the 13.5 nm wavelength. Arguably the most cost-effective and rapid path to proliferating this capability is through the development of Fresnel zoneplate-based microscopes. Given the relative obscurity of such systems, however, modeling tools are not necessarily optimized to deal with them and their imaging properties are poorly understood. Here we present a modeling methodology to analyze zoneplate microscopes based on commercially available optical modelingmore » software and use the technique to investigate the imaging performance of an off-axis EUV microscope design. The modeling predicts that superior performance can be achieved by tilting the zoneplate, making it perpendicular to the chief ray at the center of the field, while designing the zoneplate to explicitly work in that tilted plane. Although the examples presented here are in the realm of EUV mask inspection, the methods described and analysis results are broadly applicable to zoneplate microscopes in general, including full-field soft-x-ray microscopes rou tinely used in the synchrotron community.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Naulleau, Patrick P.; Mochi, Iacopo; Goldberg, Kenneth A.

Defect free masks remain one of the most significant challenges facing the commercialization of extreme ultraviolet (EUV) lithography. Progress on this front requires high-performance wavelength-specific metrology of EUV masks, including high-resolution and aerial-image microscopy performed near the 13.5 nm wavelength. Arguably the most cost-effective and rapid path to proliferating this capability is through the development of Fresnel zoneplate-based microscopes. Given the relative obscurity of such systems, however, modeling tools are not necessarily optimized to deal with them and their imaging properties are poorly understood. Here we present a modeling methodology to analyze zoneplate microscopes based on commercially available optical modelingmore » software and use the technique to investigate the imaging performance of an off-axis EUV microscope design. The modeling predicts that superior performance can be achieved by tilting the zoneplate, making it perpendicular to the chief ray at the center of the field, while designing the zoneplate to explicitly work in that tilted plane. Although the examples presented here are in the realm of EUV mask inspection, the methods described and analysis results are broadly applicable to zoneplate microscopes in general, including full-field soft-x-ray microscopes routinely used in the synchrotron community.« less

The research progress of metrological 248nm deep ultraviolent microscope inspection device

NASA Astrophysics Data System (ADS)

Wang, Zhi-xin; Li, Qi; Gao, Si-tian; Shi, Yu-shu; Li, Wei; Li, Shi

2016-01-01

In lithography process, the precision of wafer pattern to a large extent depends on the geometric dimensioning and tolerance of photomasks when accuracy of lithography aligner is certain. Since the minimum linewidth (Critical Dimension) of the aligner exposing shrinks to a few tens of nanometers in size, one-tenth of tolerance errors in fabrication may lead to microchip function failure, so it is very important to calibrate these errors of photomasks. Among different error measurement instruments, deep ultraviolent (DUV) microscope because of its high resolution, as well as its advantages compared to scanning probe microscope restrained by measuring range and scanning electron microscope restrained by vacuum environment, makes itself the most suitable apparatus. But currently there is very few DUV microscope adopting 248nm optical system, means it can attain 80nm resolution; furthermore, there is almost no DUV microscope possessing traceable calibration capability. For these reason, the National Institute of Metrology, China is developing a metrological 248nm DUV microscope mainly consists of DUV microscopic components, PZT and air supporting stages as well as interferometer calibration framework. In DUV microscopic component, the Köhler high aperture transmit condenser, DUV splitting optical elements and PMT pinhole scanning elements are built. In PZT and air supporting stages, a novel PZT actuating flexural hinge stage nested separate X, Y direction kinematics and a friction wheel driving long range air supporting stage are researched. In interferometer framework, a heterodyne multi-pass interferometer measures XY axis translation and Z axis rotation through Zerodur mirror mounted on stage. It is expected the apparatus has the capability to calibrate one dimensional linewidths and two dimensional pitches ranging from 200nm to 50μm with expanded uncertainty below 20nm.

Scanning Electron Microscopic Features of Nasolacrimal Silastic Stents Retained for Prolong Durations Following Dacryocystorhinostomy.

PubMed

Ali, Mohammad Javed; Baig, Farhana; Lakshman, Mekala; Naik, Milind N

2016-01-01

The aims of this study were to examine the scanning electron microscopic features of silastic nasolacrimal duct stents retained for long durations following a dacryocystorhinostomy. A prospective interventional study was performed on stents retrieved from patients who were lost to follow up after a dacryocystorhinostomy with Crawford stent insertion. Long duration was defined as stents retrieved at a minimum of 1 year following a dacryocystorhinostomy. None of the patients had any evidence of postoperative infection. After removal, the stent segments were subjected to biofilm and physical deposit analysis using standard protocols of scanning electron microscopy. These stent segments were compared against sterile stents which acted as controls. A total of 7 stents were studied. Five were consecutive patient samples, and 2 were sterile stents. All the 5 stents were retrieved from patients who were lost to follow up for a minimum of 12 months following surgery. The mean duration of intubation at retrieval was 21 months. All the stents demonstrated evidence of biofilm formation and physical deposits. However, as the duration of retention increased, the deposits and biofilms were noted to be progressively denser, multilayered and extensive. Certain areas demonstrated thick biofilm integration with the deposits. Polymicrobial communities were noted within the exopolysaccharide matrix. This is the first study to exclusively report on scanning electron microscopic features of lacrimal stents retained for long durations. Further studies on physical elements within the deposits and protein analysis would provide more insights into stent-tissue interactions.

[Clinical pathology on the verge of virtual microscopy].

PubMed

Tolonen, Teemu; Näpänkangas, Juha; Isola, Jorma

2015-01-01

For more than 100 years, examinations of pathology specimens have relied on the use of the light microscope. The technological progress of the last few years is enabling the digitizing of histologic specimen slides and application of the virtual microscope in diagnostics. Virtual microscopy will facilitate consultation possibilities, and digital image analysis serves to enhance the level of diagnostics. Organizing and monitoring clinicopathological meetings will become easier. Digital archive of histologic specimens and the virtual microscopy network are expected to benefit training and research as well, particularly what applies to the Finnish biobank network which is currently being established.

Transmission environmental scanning electron microscope with scintillation gaseous detection device.

PubMed

Danilatos, Gerasimos; Kollia, Mary; Dracopoulos, Vassileios

2015-03-01

A transmission environmental scanning electron microscope with use of a scintillation gaseous detection device has been implemented. This corresponds to a transmission scanning electron microscope but with addition of a gaseous environment acting both as environmental and detection medium. A commercial type of low vacuum machine has been employed together with appropriate modifications to the detection configuration. This involves controlled screening of various emitted signals in conjunction with a scintillation gaseous detection device already provided with the machine for regular surface imaging. Dark field and bright field imaging has been obtained along with other detection conditions. With a progressive series of modifications and tests, the theory and practice of a novel type of microscopy is briefly shown now ushering further significant improvements and developments in electron microscopy as a whole. Copyright © 2014 Elsevier B.V. All rights reserved.

Photorefractive keratectomy (PRK) at 193 nm using an erodible mask: new developments and clinical progress

NASA Astrophysics Data System (ADS)

Gordon, Michael; Seiler, Theo; Carey, Joseph P.; Friedman, Marc D.; Johnsson, N. M. F.; King, Michael C.; Muller, David F.

1993-06-01

This paper reports on our progress using an erodible mask to perform photorefractive keratectomy (PRK) for the correction of myopic astigmatism. We describe modifications to the mask, the mask eye cup and the surgical microscope aimed at simplifying the procedure and improving the ergonomics of the hardware. We report the clinical results of the post-op exam for 20 patients who have undergone PRK for myopic astigmatism under a Phase IIA study. The results compare favorably with an earlier Phase IIA study for performing PRK with a computer-controlled iris. Most important, the clinical data show the absence of any significant corneal haze and no significant decrease in spectacle corrected visual acuity. Although more long term follow-up is needed, the preliminary results support the safety and effectiveness of using an erodible mask to perform PRK for myopic astigmatism.

Chemistry, microscopy and smell: bloodstains and nineteenth-century legal medicine.

PubMed

Bertomeu-Sánchez, José Ramón

2015-01-01

This paper analyses the development of three methods for detecting bloodstains during the first half of the nineteenth-century in France. After dealing with the main problems in detecting bloodstains, the paper describes the chemical tests introduced in the mid-1820s. Then the first uses of the microscope in the detection of bloodstains around 1827 are discussed. The most controversial method is then examined, the smell test introduced by Jean-Pierre Barruel in 1829, and the debates which took place in French academies and learned societies during ensuing years are surveyed. Moving to the courtrooms a review is conducted of how the different methods were employed in criminal trials. By reviewing these cases, the main arguments against Barruel's test during the 1830s are explored as well as the changes making possible the return of the microscope to legal medicine around 1840. By reconstructing the history of these three methods, the paper reveals how the senses of smell and vision (colours and microscopic images) were employed in order to produce convincing evidence in both academies and courts. The paper questions two linear master narratives that are organized in terms of progress and decline: the development of forensic science as a result of continued technological progress; and the supposed decline of smell in the history of the senses, particularly in the realm of chemistry and medicine.

Seeing What We Can't See

ERIC Educational Resources Information Center

Ohana, Chris

2005-01-01

While observation is critical to science, sometimes things cannot be observed directly. Sometimes things happened long ago (in paleontology, for example) or are too small to observe (like atoms). Many students believe that science progresses only through direct observation. Students may also believe that giant microscopes provide insight into…

QUANTITATIVE FLUORESCENCE IN SITU HYBRIDIZATION OF AUREOBASIDIUM PULLULANS ON MICROSCOPE SLIDES AND LEAF SURFACES. (R823845)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Microscopic Car Modeling for Intelligent Traffic and Scenario Generation in the UCF Driving Simulator : Year 2

DOT National Transportation Integrated Search

2000-01-01

A multi-year project was initiated to introduce autonomous vehicles in the University of Central Florida (UCF) Driving Simulator for real-time interaction with the simulator vehicle. This report describes the progress during the second year. In the f...

The Study of Glioma by Xenotransplantation in Zebrafish Early Life Stages

PubMed Central

Motaln, Helena; Turnšek, Tamara Lah

2015-01-01

Zebrafish (Danio rerio) and their transparent embryos are becoming an increasingly popular tool for studying processes involved in tumor progression and in the search for novel tumor treatment approaches. The xenotransplantation of fluorescently labeled mammalian cancer cells into zebrafish embryos is an approach enabling relatively high-throughput in vivo analyses. The small size of the embryos as well as the relative simplicity of their manipulation and maintenance allow for large numbers of embryos to be processed efficiently in a short time and at low cost. Furthermore, the possibility of fluorescence microscopic imaging of tumor progression within zebrafish embryos and larvae holds unprecedented potential for the real-time visualization of these processes in vivo. This review presents the methodologies of xenotransplantation studies on zebrafish involving research on tumor invasion, proliferation, tumor-induced angiogenesis and screening for antitumor therapeutics. We further focus on the application of these zebrafish to the study of glioma; in particular, its most common and malignant form, glioblastoma. PMID:26109632

Recent progress in the microscopic description of small and large amplitude collective motion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lacroix, D., E-mail: lacroix@ipno.in2p3.fr; Tanimura, Y.; Ayik, S.

2015-10-15

Dynamical mean-field theory has recently attracted much interests to provide a unified framework for the description of many aspects of nuclear dynamics [1, 2, 3, 4, 5] (for recent reviews see [6, 7]). In particular, the inclusion of pairing correlation has opened new perspectives [8, 9, 10, 11, 12]. A summary of recent applications including giant resonances and transfer reactions will be made in this talk [13, 14, 15, 16]. While new progresses have been made with the use of sophisticated effective interactions and the development of symmetry unrestricted applications, mean-field dynamics suffer from the poor treatment of quantum fluctuationsmore » in collective space. As a consequence, these theories are successful in describing average properties of many different experimental observations but generally fail to account realistically for the width of experimental distribution. The increase of predictive power of dynamical mean-field theory is facing the difficulty of going beyond the independent particle or quasi-particle picture. Nevertheless, in the last decade, novel methods have been proposed to prepare the next generation of microscopic mean-field codes able to account for both average properties and fluctuations around the average. A review of recent progresses in this direction as well as recent applications to heavy-ion collisions will be given [17, 18].« less

A Review of Adaptive Optics Optical Coherence Tomography: Technical Advances, Scientific Applications, and the Future.

PubMed

Jonnal, Ravi S; Kocaoglu, Omer P; Zawadzki, Robert J; Liu, Zhuolin; Miller, Donald T; Werner, John S

2016-07-01

Optical coherence tomography (OCT) has enabled "virtual biopsy" of the living human retina, revolutionizing both basic retina research and clinical practice over the past 25 years. For most of those years, in parallel, adaptive optics (AO) has been used to improve the transverse resolution of ophthalmoscopes to foster in vivo study of the retina at the microscopic level. Here, we review work done over the last 15 years to combine the microscopic transverse resolution of AO with the microscopic axial resolution of OCT, building AO-OCT systems with the highest three-dimensional resolution of any existing retinal imaging modality. We surveyed the literature to identify the most influential antecedent work, important milestones in the development of AO-OCT technology, its applications that have yielded new knowledge, research areas into which it may productively expand, and nascent applications that have the potential to grow. Initial efforts focused on demonstrating three-dimensional resolution. Since then, many improvements have been made in resolution and speed, as well as other enhancements of acquisition and postprocessing techniques. Progress on these fronts has produced numerous discoveries about the anatomy, function, and optical properties of the retina. Adaptive optics OCT continues to evolve technically and to contribute to our basic and clinical knowledge of the retina. Due to its capacity to reveal cellular and microscopic detail invisible to clinical OCT systems, it is an ideal companion to those instruments and has the demonstrable potential to produce images that can guide the interpretation of clinical findings.

Elastically driven intermittent microscopic dynamics in soft solids

NASA Astrophysics Data System (ADS)

Bouzid, Mehdi; Colombo, Jader; Barbosa, Lucas Vieira; Del Gado, Emanuela

2017-06-01

Soft solids with tunable mechanical response are at the core of new material technologies, but a crucial limit for applications is their progressive aging over time, which dramatically affects their functionalities. The generally accepted paradigm is that such aging is gradual and its origin is in slower than exponential microscopic dynamics, akin to the ones in supercooled liquids or glasses. Nevertheless, time- and space-resolved measurements have provided contrasting evidence: dynamics faster than exponential, intermittency and abrupt structural changes. Here we use 3D computer simulations of a microscopic model to reveal that the timescales governing stress relaxation, respectively, through thermal fluctuations and elastic recovery are key for the aging dynamics. When thermal fluctuations are too weak, stress heterogeneities frozen-in upon solidification can still partially relax through elastically driven fluctuations. Such fluctuations are intermittent, because of strong correlations that persist over the timescale of experiments or simulations, leading to faster than exponential dynamics.

Generation-3 programmable array microscope (PAM) with digital micro-mirror device (DMD)

NASA Astrophysics Data System (ADS)

De Beule, Pieter A. A.; de Vries, Anthony H. B.; Arndt-Jovin, Donna J.; Jovin, Thomas M.

2011-03-01

We report progress on the construction of an optical sectioning programmable array microscope (PAM) implemented with a digital micro-mirror device (DMD) spatial light modulator (SLM) utilized for both fluorescence illumination and detection. The introduction of binary intensity modulation at the focal plane of a microscope objective in a computer controlled pixilated mode allows the recovery of an optically sectioned image. Illumination patterns can be changed very quickly, in contrast to static Nipkow disk or aperture correlation implementations, thereby creating an optical system that can be optimized to the optical specimen in a convenient manner, e.g. for patterned photobleaching, photobleaching reduction, or spatial superresolution. We present a third generation (Gen-3) dual path PAM module incorporating the 25 kHz binary frame rate TI 1080p DMD and a newly developed optical system that offers diffraction limited imaging with compensation of tilt angle distortion.

Recent Evolution of Endoscopic Endonasal Surgery for Treatment of Pituitary Adenomas

PubMed Central

NISHIOKA, Hiroshi

2017-01-01

For the treatment of pituitary tumors, microscopic transsphenoidal surgery has been considered the “gold standard” since the late 1960s. Over the last two decades, however, a worldwide shift towards endoscopic endonasal surgery is in progress for many reasons. These include a wide panoramic view, improved illumination, an ability to look around anatomical corners using angled tip and, in addition, application to the extended approaches for parasellar tumors. Both endoscopic and microscopic approaches appear equally effective for nonfunctioning adenomas without significant suprasellar or lateral extensions, whereas the endoscopic approach may improve outcomes associated with the extent of resection and postoperative complications for larger tumors. Despite many theoretical benefits in the endoscopic surgery, remission rates of functioning adenomas do not substantially differ between the approaches in experienced hands. The endoscopic approach is a valid alternative to the microscopic approach for adenomas. The benefits will be more appreciated in the extended surgery for parasellar tumors. PMID:28239067

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yashchuk, Valeriy V; Conley, Raymond; Anderson, Erik H.

We discuss the results of SEM and TEM measurements with the BPRML test samples fabricated from a BPRML (WSi2/Si with fundamental layer thickness of 3 nm) with a Dual Beam FIB (focused ion beam)/SEM technique. In particular, we demonstrate that significant information about the metrological reliability of the TEM measurements can be extracted even when the fundamental frequency of the BPRML sample is smaller than the Nyquist frequency of the measurements. The measurements demonstrate a number of problems related to the interpretation of the SEM and TEM data. Note that similar BPRML test samples can be used to characterize x-raymore » microscopes. Corresponding work with x-ray microscopes is in progress.« less

Arachnoid Cyst in the Middle Cranial Fossa Presenting with Pulsatile Exophthalmos: Case Report and Literature Review

PubMed Central

SAITO, Atsushi; KON, Hiroyuki; HARYU, Shinya; MINO, Masaki; SASAKI, Tatsuya; NISHIJIMA, Michiharu

2014-01-01

A 20-year-old woman suffered gradual progression of right pulsatile exophthalmos and slight headache. Computed tomography (CT) demonstrated outward and downward displacement of the right globe and an arachnoid cyst in the right middle cranial fossa associated with thinned and anterior protrusion of a bony orbit. Microscopic cystocisternotomy was performed and the cerebrospinal fluid (CSF) inside of the cyst communicated into the carotid cistern and cistern in the posterior cranial fossa. Pulsatile exophthalmos improved immediately after surgery. Arachnoid cyst in the middle cranial fossa presenting with exophthalmos is rare. Microscopic cystocisternotomy might successfully improve CSF flow and relieve exophthalmos. PMID:24305013

MACROSCOPIC AND MICROSCOPIC OBSERVATIONS OF PARTICLE-FACILITATED MERCURY TRANSPORT FROM NEW IDRIA AND SULPHUR BANK MERCURY MINE TAILINGS (R827634)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

PARTICLE-FACILITATED MERCURY TRANSPORT FROM NEW IDRIA AND SULPHUR BANK MERCURY MINE TAILINGS. 2. MICROSCOPIC AND SPECTROSCOPIC ANALYSIS. (R827634)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

The Behavior of Matter Under Nonequilibrium Conditions: Fundamental Aspects and Applications: Progress Report for Period April 15,1990 - April 14, 1991

DOE R&D Accomplishments Database

Prigogine, I.

1990-12-01

Our report contains a brief summary of what has been achieved over the period of the contract. We have studied the behavior of matter under nonequilibrium conditions on three levels: (1) on the microscopic level in the frame of classical mechanics or of quantum theory; (2) on the stochastic level, which includes fluctuations; and (3) on the phenomenological, macroscopic level described by nonlinear equations. We first report on the level (1), then report on the levels (2) and (3).

Electron beam dynamics in an ultrafast transmission electron microscope with Wehnelt electrode.

PubMed

Bücker, K; Picher, M; Crégut, O; LaGrange, T; Reed, B W; Park, S T; Masiel, D J; Banhart, F

2016-12-01

High temporal resolution transmission electron microscopy techniques have shown significant progress in recent years. Using photoelectron pulses induced by ultrashort laser pulses on the cathode, these methods can probe ultrafast materials processes and have revealed numerous dynamic phenomena at the nanoscale. Most recently, the technique has been implemented in standard thermionic electron microscopes that provide a flexible platform for studying material's dynamics over a wide range of spatial and temporal scales. In this study, the electron pulses in such an ultrafast transmission electron microscope are characterized in detail. The microscope is based on a thermionic gun with a Wehnelt electrode and is operated in a stroboscopic photoelectron mode. It is shown that the Wehnelt bias has a decisive influence on the temporal and energy spread of the picosecond electron pulses. Depending on the shape of the cathode and the cathode-Wehnelt distance, different emission patterns with different pulse parameters are obtained. The energy spread of the pulses is determined by space charge and Boersch effects, given by the number of electrons in a pulse. However, filtering effects due to the chromatic aberrations of the Wehnelt electrode allow the extraction of pulses with narrow energy spreads. The temporal spread is governed by electron trajectories of different length and in different electrostatic potentials. High temporal resolution is obtained by excluding shank emission from the cathode and aberration-induced halos in the emission pattern. By varying the cathode-Wehnelt gap, the Wehnelt bias, and the number of photoelectrons in a pulse, tradeoffs between energy and temporal resolution as well as beam intensity can be made as needed for experiments. Based on the characterization of the electron pulses, the optimal conditions for the operation of ultrafast TEMs with thermionic gun assembly are elaborated. Copyright © 2016 Elsevier B.V. All rights reserved.

UHV-TEM-REM Studies of Si(111) Surfaces

NASA Astrophysics Data System (ADS)

Yagi, K.; Yamanaka, A.; Sato, H.; Shima, M.; Ohse, H.; Ozawa, S.; Tanishiro, Y.

Recent progresses of ultra-high vacuum transmission and reflection electron microscope studies of clean Si(111) surfaces are described. Anisotropy of surface atomic steps such as step energy, bunching of steps, are studied. Out of phase boundaries are observed in transmission mode and its energy relative to the step energy is studied. The phase transition between the 1 × 1 and the 7 × 7 structures around 830°C, studied previously is re-examined under various conditions. Contraction strains of the 7 × 7 structure and adatom density on terraces play important role during the transition. Diffuse scattering observed by LEED and RHEED above the transition temperature is not observed in teh TED pattern from a thin film.

A STED-FLIM microscope applied to imaging the natural killer cell immune synapse

NASA Astrophysics Data System (ADS)

Lenz, M. O.; Brown, A. C. N.; Auksorius, E.; Davis, D. M.; Dunsby, C.; Neil, M. A. A.; French, P. M. W.

2011-03-01

We present a stimulated emission depletion (STED) fluorescence lifetime imaging (FLIM) microscope, excited by a microstructured optical fibre supercontinuum source that is pumped by a femtosecond Ti:Sapphire-laser, which is also used for depletion. Implemented using a piezo-scanning stage on a laser scanning confocal fluorescence microscope system with FLIM realised using time correlated single photon counting (TCSPC), this provides convenient switching between confocal and STED-FLIM with spatial resolution down to below 60 nm. We will present our design considerations to make a robust instrument for biological applications including a comparison between fixed phase plate and spatial light modulator (SLM) approaches to shape the STED beam and the correlation of STED and confocal FLIM microscopy. Following our previous application of FLIM-FRET to study intercellular signalling at the immunological synapse (IS), we are employing STED microscopy to characterize the spatial distribution of cellular molecules with subdiffraction resolution at the IS. In particular, we are imaging cytoskeletal structure at the Natural Killer cell activated immune synapse. We will also present our progress towards multilabel STED microscopy to determine how relative spatial molecular organization, previously undetectable by conventional microscopy techniques, is important for NK cell cytotoxic function. Keywords: STED, Stimulated Emission Depletion Microscopy, Natural Killer (NK) cell, Fluorescence lifetime imaging, FLIM, Super resolution microscopy.

NONIDEAL TRANSPORT OF REACTIVE SOLUTES IN HETEROGENEOUS POROUS MEDIA 6. MICROSCOPIC AND MACROSCOPIC APPROACHES FOR INCORPORATING HETEROGENEOUS RATE-LIMITED MASS TRANSFER. (R825407)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Quantum Monte Carlo Methods for First Principles Simulation of Liquid Water

ERIC Educational Resources Information Center

Gergely, John Robert

2009-01-01

Obtaining an accurate microscopic description of water structure and dynamics is of great interest to molecular biology researchers and in the physics and quantum chemistry simulation communities. This dissertation describes efforts to apply quantum Monte Carlo methods to this problem with the goal of making progress toward a fully "ab initio"…

White grain mycetoma caused by Scedosporium apiospermum in North India: a case report.

PubMed

Gupta, Munesh Kumar; Banerjee, Tuhina; Kumar, Dhirendra; Rastogi, Amit; Tilak, Ragini

2013-12-01

Mycetoma is chronic granulomatous infection of skin and subcutaneous tissue caused by both bacteria and fungi. We report a case of mycetoma caused by Scedosporium apiospermum in the right foot of a 45-year-old farmer in north India. The patient had a history of trauma in the sole of the right foot followed by discharge of white granules along with proximal progression. Scedosporium apiospermum was identified based on colony characteristics and microscopic features on slide culture. Mycetoma is a progressive disease. Foot is commonly affected in persons who walk barefoot, especially in south India. Untreated mycetoma progress and involve the underlying fasciae and tissues along with bones often resulting in loss of limb. By prompt and reliable diagnosis with corresponding antimicrobial administration, we can prevent further progression and limb disability.

Effects of electrocautery to provoke endovascular thermal injury.

PubMed

Rossi, Fabio Henrique; Izukawa, Nilo Mitsuru; Silva, Domingos Guerino; Chen, Juliana; Prakasan, Akash Kuzhiparambil; Zamorano, Mabel Moura Barros; Silva, Lílian Mary

2011-10-01

To investigate the effects of a new electrocautery device to provoke endovascular venous thermal injury. An experimental endovascular electrocautery was placed inside eight ex-vivo bovine saphenous veins models. Each one was divided in eight segments and progressive intensities of electric energy liberated. The macroscopic and microscopic effects were analyzed. Forty bovine saphenous veins segments were studied. The higher the electric energy applied the greater the nuclear picnosis and more intense the cytoplasmatic shrinkage and electrocoagulation effects. The experimental endovascular electrocautery device demonstrated to be both capable of inducing the destruction of the intimal layers of the studied vein model and provoke endovascular thermal injury.

The fragile elderly hip: Mechanisms associated with age-related loss of strength and toughness☆

PubMed Central

Reeve, Jonathan; Loveridge, Nigel

2014-01-01

Every hip fracture begins with a microscopic crack, which enlarges explosively over microseconds. Most hip fractures in the elderly occur on falling from standing height, usually sideways or backwards. The typically moderate level of trauma very rarely causes fracture in younger people. Here, this paradox is traced to the decline of multiple protective mechanisms at many length scales from nanometres to that of the whole femur. With normal ageing, the femoral neck asymmetrically and progressively loses bone tissue precisely where the cortex is already thinnest and is also compressed in a sideways fall. At the microscopic scale of the basic remodelling unit (BMU) that renews bone tissue, increased numbers of actively remodelling BMUs associated with the reduced mechanical loading in a typically inactive old age augments the numbers of mechanical flaws in the structure potentially capable of initiating cracking. Menopause and over-deep osteoclastic resorption are associated with incomplete BMU refilling leading to excessive porosity, cortical thinning and disconnection of trabeculae. In the femoral cortex, replacement of damaged bone or bone containing dead osteocytes is inefficient, impeding the homeostatic mechanisms that match strength to habitual mechanical usage. In consequence the participation of healthy osteocytes in crack-impeding mechanisms is impaired. Observational studies demonstrate that protective crack deflection in the elderly is reduced. At the most microscopic levels attention now centres on the role of tissue ageing, which may alter the relationship between mineral and matrix that optimises the inhibition of crack progression and on the role of osteocyte ageing and death that impedes tissue maintenance and repair. This review examines recent developments in the understanding of why the elderly hip becomes fragile. This growing understanding is suggesting novel testable approaches for reducing risk of hip fracture that might translate into control of the growing worldwide impact of hip fractures on our ageing populations. PMID:24412288

Adenoid cystic carcinoma of the skull base: results with an aggressive multidisciplinary approach.

PubMed

Ramakrishna, Rohan; Raza, Shaan M; Kupferman, Michael; Hanna, Ehab; DeMonte, Franco

2016-01-01

OBJECT Adenoid cystic carcinoma (ACC) is a locally aggressive tumor of salivary gland origin. Little data exist to guide treatment when this tumor extends to involve the structures of the skull base. METHODS Fifty-one patients with a diagnosis of ACC affecting the skull base were identified from a prospective database at MD Anderson Cancer Center (from 1992 to 2010). RESULTS Median follow-up for study patients was 6.75 years. The 5- and 10-year overall survival (OS) rates were 78% and 50%, respectively. Sixty-six percent of patients had progression of their disease. The 5- and 10-year progression-free survival (PFS) rates were 46.7% and 21.0%, respectively. Gross-total resection was achieved in 75% of patients, with 49% having microscopically negative margins at the time of first operation. On univariate analysis, resections with microscopically negative margins were associated with a significant OS advantage (20.1 ± 3.3 years) compared with resections that left residual disease, even if microscopic (10.3 ± 1.6 years, p = 0.035). In patients who underwent reoperation, the effect persisted, with improved OS in those with negative margins (21.4 ± 0.0 vs 16.7 ± 4.0 years, p = 0.06). The use of adjuvant radiotherapy was associated with an OS advantage (16.2 ± 2.5 vs 5.5 ± 2.2 years, p = 0.03) at initial diagnosis and improved PFS (7.8 ± 1.0 vs 2.1 ± 0.62 years, p = 0.005), whereas repeat irradiation provided no benefit. The use of adjuvant chemotherapy at diagnosis or at recurrence was not associated with any significant advantage. Multivariate analysis revealed margin-negative resection at initial operation and at recurrence retained OS significance, even after controlling for age, radiation therapy, and T stage. CONCLUSIONS ACC of the skull base is best treated with a multidisciplinary approach aimed at maximal, safe resection. Adjuvant radiotherapy should be offered, whereas chemotherapy does not confer benefit.

Multiscale modelling and analysis of collective decision making in swarm robotics.

PubMed

Vigelius, Matthias; Meyer, Bernd; Pascoe, Geoffrey

2014-01-01

We present a unified approach to describing certain types of collective decision making in swarm robotics that bridges from a microscopic individual-based description to aggregate properties. Our approach encompasses robot swarm experiments, microscopic and probabilistic macroscopic-discrete simulations as well as an analytic mathematical model. Following up on previous work, we identify the symmetry parameter, a measure of the progress of the swarm towards a decision, as a fundamental integrated swarm property and formulate its time evolution as a continuous-time Markov process. Contrary to previous work, which justified this approach only empirically and a posteriori, we justify it from first principles and derive hard limits on the parameter regime in which it is applicable.

Wetting Hysteresis at the Molecular Scale

NASA Technical Reports Server (NTRS)

Jin, Wei; Koplik, Joel; Banavar, Jayanth R.

1996-01-01

The motion of a fluid-fluid-solid contact line on a rough surface is well known to display hysteresis in the contact angle vs. velocity relationship. In order to understand the phenomenon at a fundamental microscopic level, we have conducted molecular dynamics computer simulations of a Wilhelmy plate experiment in which a solid surface is dipped into a liquid bath, and the force-velocity characteristics are measured. We directly observe a systematic variation of force and contact angle with velocity, which is single-valued for the case of an atomically smooth solid surface. In the microscopically rough case, however, we find (as intuitively expected) an open hysteresis loop. Further characterization of the interface dynamics is in progress.

[Progress of researches on mechanism of acupuncture therapy underlying improvement of acute cerebral hemorrhage].

PubMed

Wang, Fan; Wang, Hai-qiao; Dong, Gui-rong

2011-04-01

In the present paper, the authors review the progress of researches on the mechanism of acupuncture therapy underlying improvement of acute cerebral hemorrhage from experimental studies and research methods. The effects of acupuncture intervention mainly involve (1) lessening inflammatory reactions, (2) reducing impairment of free radicals and excitatory amino acids on cerebral neurons, (3) balancing release of vascular bioactive substances to increase regional cerebral blood flow, and (4) promoting repair and regeneration of the neural tissue, etc. In regard to the research methods, many new biological techniques such as biological molecular approaches, neuro-cellular chemical methods, reverse transcription-polymerase chain reaction (RT-PCR) or quantitative real time-PCR, situ hybridization, western blotting, electron microscope, etc., have been extensively applied to researches on the underlying mechanism of acupuncture therapy for cerebral infarction. In addition, the authors also pointed out that in spite of achieving some bigger progresses in experimental studies, most of the results basically reflect static, isolated and regional changes rather than dynamic and whole body changes. For this reason, more vivo research techniques and noninvasive research methods are highly recommended to be used in the future research on the underlying mechanisms of acupuncture therapy for acute cerebral ischemia.

A Review of Adaptive Optics Optical Coherence Tomography: Technical Advances, Scientific Applications, and the Future

PubMed Central

Jonnal, Ravi S.; Kocaoglu, Omer P.; Zawadzki, Robert J.; Liu, Zhuolin; Miller, Donald T.; Werner, John S.

2016-01-01

Purpose Optical coherence tomography (OCT) has enabled “virtual biopsy” of the living human retina, revolutionizing both basic retina research and clinical practice over the past 25 years. For most of those years, in parallel, adaptive optics (AO) has been used to improve the transverse resolution of ophthalmoscopes to foster in vivo study of the retina at the microscopic level. Here, we review work done over the last 15 years to combine the microscopic transverse resolution of AO with the microscopic axial resolution of OCT, building AO-OCT systems with the highest three-dimensional resolution of any existing retinal imaging modality. Methods We surveyed the literature to identify the most influential antecedent work, important milestones in the development of AO-OCT technology, its applications that have yielded new knowledge, research areas into which it may productively expand, and nascent applications that have the potential to grow. Results Initial efforts focused on demonstrating three-dimensional resolution. Since then, many improvements have been made in resolution and speed, as well as other enhancements of acquisition and postprocessing techniques. Progress on these fronts has produced numerous discoveries about the anatomy, function, and optical properties of the retina. Conclusions Adaptive optics OCT continues to evolve technically and to contribute to our basic and clinical knowledge of the retina. Due to its capacity to reveal cellular and microscopic detail invisible to clinical OCT systems, it is an ideal companion to those instruments and has the demonstrable potential to produce images that can guide the interpretation of clinical findings. PMID:27409507

A versatile LabVIEW and field-programmable gate array-based scanning probe microscope for in operando electronic device characterization.

PubMed

Berger, Andrew J; Page, Michael R; Jacob, Jan; Young, Justin R; Lewis, Jim; Wenzel, Lothar; Bhallamudi, Vidya P; Johnston-Halperin, Ezekiel; Pelekhov, Denis V; Hammel, P Chris

2014-12-01

Understanding the complex properties of electronic and spintronic devices at the micro- and nano-scale is a topic of intense current interest as it becomes increasingly important for scientific progress and technological applications. In operando characterization of such devices by scanning probe techniques is particularly well-suited for the microscopic study of these properties. We have developed a scanning probe microscope (SPM) which is capable of both standard force imaging (atomic, magnetic, electrostatic) and simultaneous electrical transport measurements. We utilize flexible and inexpensive FPGA (field-programmable gate array) hardware and a custom software framework developed in National Instrument's LabVIEW environment to perform the various aspects of microscope operation and device measurement. The FPGA-based approach enables sensitive, real-time cantilever frequency-shift detection. Using this system, we demonstrate electrostatic force microscopy of an electrically biased graphene field-effect transistor device. The combination of SPM and electrical transport also enables imaging of the transport response to a localized perturbation provided by the scanned cantilever tip. Facilitated by the broad presence of LabVIEW in the experimental sciences and the openness of our software solution, our system permits a wide variety of combined scanning and transport measurements by providing standardized interfaces and flexible access to all aspects of a measurement (input and output signals, and processed data). Our system also enables precise control of timing (synchronization of scanning and transport operations) and implementation of sophisticated feedback protocols, and thus should be broadly interesting and useful to practitioners in the field.

A versatile LabVIEW and field-programmable gate array-based scanning probe microscope for in operando electronic device characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berger, Andrew J., E-mail: berger.156@osu.edu; Page, Michael R.; Young, Justin R.

Understanding the complex properties of electronic and spintronic devices at the micro- and nano-scale is a topic of intense current interest as it becomes increasingly important for scientific progress and technological applications. In operando characterization of such devices by scanning probe techniques is particularly well-suited for the microscopic study of these properties. We have developed a scanning probe microscope (SPM) which is capable of both standard force imaging (atomic, magnetic, electrostatic) and simultaneous electrical transport measurements. We utilize flexible and inexpensive FPGA (field-programmable gate array) hardware and a custom software framework developed in National Instrument's LabVIEW environment to perform themore » various aspects of microscope operation and device measurement. The FPGA-based approach enables sensitive, real-time cantilever frequency-shift detection. Using this system, we demonstrate electrostatic force microscopy of an electrically biased graphene field-effect transistor device. The combination of SPM and electrical transport also enables imaging of the transport response to a localized perturbation provided by the scanned cantilever tip. Facilitated by the broad presence of LabVIEW in the experimental sciences and the openness of our software solution, our system permits a wide variety of combined scanning and transport measurements by providing standardized interfaces and flexible access to all aspects of a measurement (input and output signals, and processed data). Our system also enables precise control of timing (synchronization of scanning and transport operations) and implementation of sophisticated feedback protocols, and thus should be broadly interesting and useful to practitioners in the field.« less

Evaluation of the human hair root for DNA typing subsequent to microscopic comparison.

PubMed

Linch, C A; Smith, S L; Prahlow, J A

1998-03-01

Telogen human hairs are one of the most common useful evidence findings at crime scenes and/or on homicide victims. Occasionally, the microscopic characterization of the found telogen hair is the only physical evidence association to a victim or suspect. Recently efforts to characterize these hairs by mitochondrial DNA (mtDNA) methods have progressed. The nature of the telogen hair root morphology and ultrastructure has, however, been largely ignored. Examiners have recognized these hairs are unlikely to be typable by nuclear DNA (nuDNA) methods. Most forensic biologists have little knowledge of the complex cellular composition of anagen, catagen, and telogen hair roots or their morphogenesis. This paper reviews ex situ human hair root morphology as it relates to the likelihood of successful nuclear DNA typing. Dermatology texts of hair root morphology always demonstrate their microscopic appearance in the skin. This study investigates the use of fluorescence in situ hybridization (FISH) methods to sex type telogen head hairs, and it further investigates hair root morphology as it relates to the potential nuclear DNA content of evidence hairs. There is a need for the use of appropriate, consensus terminology for describing hair root morphology. There is also a need for standardized laboratory light microscopic methods in evaluating a hair root for DNA typing. FISH was found to be an unsuitable technique for sex determination of telogen hair clubs. It was determined that anagen/catagen hair roots without translucent sheath material are excellent candidates for nuDNA PCR-based typing and that hairs with telogen club root material only should not be submitted for nuDNA typing attempts.

Optical Coherence Tomography for Retinal Surgery: Perioperative Analysis to Real-Time Four-Dimensional Image-Guided Surgery.

PubMed

Carrasco-Zevallos, Oscar M; Keller, Brenton; Viehland, Christian; Shen, Liangbo; Seider, Michael I; Izatt, Joseph A; Toth, Cynthia A

2016-07-01

Magnification of the surgical field using the operating microscope facilitated profound innovations in retinal surgery in the 1970s, such as pars plana vitrectomy. Although surgical instrumentation and illumination techniques are continually developing, the operating microscope for vitreoretinal procedures has remained essentially unchanged and currently limits the surgeon's depth perception and assessment of subtle microanatomy. Optical coherence tomography (OCT) has revolutionized clinical management of retinal pathology, and its introduction into the operating suite may have a similar impact on surgical visualization and treatment. In this article, we review the evolution of OCT for retinal surgery, from perioperative analysis to live volumetric (four-dimensional, 4D) image-guided surgery. We begin by briefly addressing the benefits and limitations of the operating microscope, the progression of OCT technology, and OCT applications in clinical/perioperative retinal imaging. Next, we review intraoperative OCT (iOCT) applications using handheld probes during surgical pauses, two-dimensional (2D) microscope-integrated OCT (MIOCT) of live surgery, and volumetric MIOCT of live surgery. The iOCT discussion focuses on technological advancements, applications during human retinal surgery, translational difficulties and limitations, and future directions.

Telepathology. Long-distance diagnosis.

PubMed

Weinstein, R S; Bloom, K J; Rozek, L S

1989-04-01

Telepathology is defined as the practice of pathology at a distance, by visualizing an image on a video monitor rather than viewing a specimen directly through a microscope. Components of a telepathology system include the following: (1) a workstation equipped with a high-resolution video camera attached to a remote-controlled light microscope; (2) a pathologist workstation incorporating controls for manipulating the robotic microscope as well as a high-resolution video monitor; and (3) a telecommunications link. Progress has been made in designing and constructing telepathology workstations and fully motorized, computer-controlled light microscopes suitable for telepathology. In addition, components such as video signal digital encoders and decoders that produce remarkably stable, high-color fidelity, and high-resolution images have been incorporated into the workstations. Resolution requirements for the video microscopy component of telepathology have been formally examined in receiver operator characteristic (ROC) curve analyses. Test-of-concept demonstrations have been completed with the use of geostationary satellites as the broadband communication linkages for 750-line resolution video. Potential benefits of telepathology include providing a means of conveniently delivering pathology services in real-time to remote sites or underserviced areas, time-sharing of pathologists' services by multiple institutions, and increasing accessibility to specialty pathologists.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yashchuk, V.V.; Conley, R.; Anderson, E.H.

Verification of the reliability of metrology data from high quality X-ray optics requires that adequate methods for test and calibration of the instruments be developed. For such verification for optical surface profilometers in the spatial frequency domain, a modulation transfer function (MTF) calibration method based on binarypseudo-random (BPR) gratings and arrays has been suggested and and proven to be an effective calibration method for a number of interferometric microscopes, a phase shifting Fizeau interferometer, and a scatterometer. Here we describe the details of development of binarypseudo-random multilayer (BPRML) test samples suitable for characterization of scanning (SEM) and transmission (TEM) electronmore » microscopes. We discuss the results of TEM measurements with the BPRML test samples fabricated from a WiSi{sub 2}/Si multilayer coating with pseudo-randomly distributed layers. In particular, we demonstrate that significant information about the metrological reliability of the TEM measurements can be extracted even when the fundamental frequency of the BPRML sample is smaller than the Nyquist frequency of the measurements. The measurements demonstrate a number of problems related to the interpretation of the SEM and TEM data. Note that similar BPRML testsamples can be used to characterize X-ray microscopes. Corresponding work with X-ray microscopes is in progress.« less

Optical Coherence Tomography for Retinal Surgery: Perioperative Analysis to Real-Time Four-Dimensional Image-Guided Surgery

PubMed Central

Carrasco-Zevallos, Oscar M.; Keller, Brenton; Viehland, Christian; Shen, Liangbo; Seider, Michael I.; Izatt, Joseph A.; Toth, Cynthia A.

2016-01-01

Magnification of the surgical field using the operating microscope facilitated profound innovations in retinal surgery in the 1970s, such as pars plana vitrectomy. Although surgical instrumentation and illumination techniques are continually developing, the operating microscope for vitreoretinal procedures has remained essentially unchanged and currently limits the surgeon's depth perception and assessment of subtle microanatomy. Optical coherence tomography (OCT) has revolutionized clinical management of retinal pathology, and its introduction into the operating suite may have a similar impact on surgical visualization and treatment. In this article, we review the evolution of OCT for retinal surgery, from perioperative analysis to live volumetric (four-dimensional, 4D) image-guided surgery. We begin by briefly addressing the benefits and limitations of the operating microscope, the progression of OCT technology, and OCT applications in clinical/perioperative retinal imaging. Next, we review intraoperative OCT (iOCT) applications using handheld probes during surgical pauses, two-dimensional (2D) microscope-integrated OCT (MIOCT) of live surgery, and volumetric MIOCT of live surgery. The iOCT discussion focuses on technological advancements, applications during human retinal surgery, translational difficulties and limitations, and future directions. PMID:27409495

Dynamics of hot rotating nuclei

NASA Astrophysics Data System (ADS)

Garcias, F.; de La Mota, V.; Remaud, B.; Royer, G.; Sébille, F.

1991-02-01

The deexcitation of hot rotating nuclei is studied within a microscopic semiclassical transport formalism. This framework allows the study of the competition between the fission and evaporation channels of deexcitation, including the mean-field and two-body interactions, without shape constraint for the fission channel. As a function of initial angular momenta and excitation energies, the transitions between three regimes is analyzed [particle evaporation, binary (ternary) fussion and multifragmentation], which correspond to well-defined symmetry breakings in the inertia tensor of the system. The competition between evaporation and binary fission is studied, showing the progressive disappearance of the fission process with increasing excitation energies, up to a critical point where nuclei pass directly from evaporation to multifragmentation channels.

O5.05FLUORESCEIN-GUIDED REMOVAL OF HIGH-GRADE GLIOMAS WITH A DEDICATED FILTER ON THE SURGICAL MICROSCOPE: PRELIMINARY RESULTS OF THE FLUOGLIO STUDY

PubMed Central

Acerbi, F.; Broggi, M.; Cavallo, C.; Anghileri, E.; Eoli, M.; Schiariti, M.; Corte, E. La; Pollo, B.; Boffano, C.; Ferroli, P.

2014-01-01

BACKGROUND: Fluorescein is a fluorescent tracer that can be used for many applications. It is able to accumulate in brain areas with blood-brain barrier disruption, and thus it can be considered an ideal dye for intraoperative visualization of high-grade gliomas (HGG). We report the preliminary results of a phase II trail (FLUOGLIO) on a new fluorescein-guided technique to remove HHG with a dedicated filter on the surgical microscope. METHODS: In September 2011 we started a prospective phase II-trial (FLUOGLIO) to evaluated safety and obtain initial indications about efficacy of fluorescein-guided surgery for HGG. Patients with suspected HGG amenable to complete resection of contrast-enhancing area were eligible to participate in this study. This report is based on the analysis of the short- and long-term results in 28 consecutive patients with HGG (age range 45-74 years), enrolled since September 2011. Fluorescein was intravenous (i.v.) injected after intubation (5-10 mg/Kg). Tumor was removed with microsurgical technique and fluorescence visualization by BLU400 or YELLOW560 filters on Pentero microscope (Carl Zeiss, Germany). The study was approved by our Ethical Committee and registered on the European Regulatory Authorities website (EudraCT No. 2011-002527-18). RESULTS: Median pre-operative tumor volume was 33.1 cm3 (2.4-87.8 cm3). We found no adverse reaction to fluorescein administration. Tumor was completely removed in 80% of the patients. Median follow-up was 10 months. 6 months Progression-free Survival (PFS) and median survival were respectively 71.4 % and 11 months. CONCLUSION: Our analysis suggested that fluorescein-guided technique with a dedicated filter on the surgical microscope is safe and allows high-rate of complete resection of contrast-enhanced tumor at the early post-operative MRI.

Comparison of fluorescence microscopy and solid-phase cytometry methods for counting bacteria in water

USGS Publications Warehouse

Lisle, John T.; Hamilton, Martin A.; Willse, Alan R.; McFeters, Gordon A.

2004-01-01

Total direct counts of bacterial abundance are central in assessing the biomass and bacteriological quality of water in ecological and industrial applications. Several factors have been identified that contribute to the variability in bacterial abundance counts when using fluorescent microscopy, the most significant of which is retaining an adequate number of cells per filter to ensure an acceptable level of statistical confidence in the resulting data. Previous studies that have assessed the components of total-direct-count methods that contribute to this variance have attempted to maintain a bacterial cell abundance value per filter of approximately 106 cells filter-1. In this study we have established the lower limit for the number of bacterial cells per filter at which the statistical reliability of the abundance estimate is no longer acceptable. Our results indicate that when the numbers of bacterial cells per filter were progressively reduced below 105, the microscopic methods increasingly overestimated the true bacterial abundance (range, 15.0 to 99.3%). The solid-phase cytometer only slightly overestimated the true bacterial abundances and was more consistent over the same range of bacterial abundances per filter (range, 8.9 to 12.5%). The solid-phase cytometer method for conducting total direct counts of bacteria was less biased and performed significantly better than any of the microscope methods. It was also found that microscopic count data from counting 5 fields on three separate filters were statistically equivalent to data from counting 20 fields on a single filter.

Imaging C. elegans embryos using an epifluorescent microscope and open source software.

PubMed

Verbrugghe, Koen J C; Chan, Raymond C

2011-03-24

Cellular processes, such as chromosome assembly, segregation and cytokinesis,are inherently dynamic. Time-lapse imaging of living cells, using fluorescent-labeled reporter proteins or differential interference contrast (DIC) microscopy, allows for the examination of the temporal progression of these dynamic events which is otherwise inferred from analysis of fixed samples(1,2). Moreover, the study of the developmental regulations of cellular processes necessitates conducting time-lapse experiments on an intact organism during development. The Caenorhabiditis elegans embryo is light-transparent and has a rapid, invariant developmental program with a known cell lineage(3), thus providing an ideal experiment model for studying questions in cell biology(4,5)and development(6-9). C. elegans is amendable to genetic manipulation by forward genetics (based on random mutagenesis(10,11)) and reverse genetics to target specific genes (based on RNAi-mediated interference and targeted mutagenesis(12-15)). In addition, transgenic animals can be readily created to express fluorescently tagged proteins or reporters(16,17). These traits combine to make it easy to identify the genetic pathways regulating fundamental cellular and developmental processes in vivo(18-21). In this protocol we present methods for live imaging of C. elegans embryos using DIC optics or GFP fluorescence on a compound epifluorescent microscope. We demonstrate the ease with which readily available microscopes, typically used for fixed sample imaging, can also be applied for time-lapse analysis using open-source software to automate the imaging process.

Early axonal damage and progressive myelin pathology define the kinetics of CNS histopathology in a mouse model of multiple sclerosis.

PubMed

Recks, Mascha S; Stormanns, Eva R; Bader, Jonas; Arnhold, Stefan; Addicks, Klaus; Kuerten, Stefanie

2013-10-01

Studies of MS histopathology are largely dependent on suitable animal models. While light microscopic analysis gives an overview of tissue pathology, it falls short in evaluating detailed changes in nerve fiber morphology. The ultrastructural data presented here and obtained from studies of myelin oligodendrocyte glycoprotein (MOG):35-55-induced experimental autoimmune encephalomyelitis (EAE) in C57BL/6 mice delineate that axonal damage and myelin pathology follow different kinetics in the disease course. While myelin pathology accumulated with disease progression, axonal damage coincided with the initial clinical disease symptoms and remained stable over time. This pattern applied both to irreversible axolysis and early axonal pathology. Notably, these histopathological patterns were reflected by the normal-appearing white matter (NAWM), suggesting that the NAWM is also in an active neurodegenerative state. The data underline the need for neuroprotection in MS and suggest the MOG model as a highly valuable tool for the assessment of different therapeutic strategies. Copyright © 2013 Elsevier Inc. All rights reserved.

Electron microscopy of hydrocarbon production in parthenium argentatum (guayule)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bauer, Thomas E.

1977-11-01

The electron microscope was used to study the biological processes involved in hydrocarbon production. The little desert shrub Guayule (Parthenium argentatum) was selected for study. This shrub can produce hydrocarbons (rubber) in concentrations up to 1/4 of its dry weight. It grows on semi-arid land and has been extensively studied. The potential of Guayule is described in detail. Results of an investigation into the morphology of Guayule at the electron microscope level are given. Experiments, which would allow the biosynthesis of hydrocarbon in Guayule to be followed, were designed. In order to do this, knowledge of the biochemistry of rubbermore » formation was used to select a tracer, mevalonic acid. Mevalonic acid is the precursor of all the terpenoids, a large class of hydrocarbons which includes rubber. It was found that when high enough concentrations of mevalonic acid are administered to seedling Guayule plants, build-ups of metabolized products are found within the chloroplasts of the seedlings. Also, tritium labeled mevalonic acid was used as a precursor, and its metabolic progress was followed by using the technique of electron microscope autoradiography. The results of these experiments also implicated chloroplasts of the Guayule plant in hydrocarbon production. The final task was the development of a system to produce three-dimensional stereo reconstructions of organelles suspected of involvement in hydrocarbon biosynthesis in Guayule. The techniques are designed to reconstruct an object from serial sections of that object. The techniques use stereo imaging both to abstract information for computer processing, and also in the computer produced reconstruction.« less

Severe tracheal stenosis with tracheopathia osteoplastica-like changes due to traumatic blunt injury.

PubMed

Kakinuma, Kazutaka; Morikawa, Kei; Miyamoto, Yasuhiro; Saji, Hisashi; Mineshita, Masamichi; Miyazawa, Teruomi

2014-12-01

A 17-year-old man was injured in a motorcycle accident, leading to a complex cerebral contusion and hepatic injury. Approximately one month after being discharged from the hospital, the patient experienced gradually progressive dyspnea on exertion. Chest computed tomography revealed severe upper tracheal stenosis; thus, emergency tracheotomy and subsequent tracheoplasty were performed. Microscopically, the deformation of tracheal cartilage and extensive interstitial ossification/fibro-elastic changes were observed. To our knowledge, this is the first report documenting the ossification of the trachea that rapidly progressed after injury, which was confirmed by surgical resection of the upper trachea.

Progressive outer retinal necrosis after rituximab and cyclophosphamide therapy.

PubMed

Dogra, Mohit; Bajgai, Priya; Kumar, Ashok; Sharma, Aman

2018-04-01

We report a case of progressive outer retinal necrosis (PORN) in a patient of microscopic polyangitis (MPA), being treated with immunosuppressive drugs such as cyclophosphamide and rituximab. Her aqueous tap was positive for Varicella Zoster virus and she was treated with oral and intravitreal antivirals, along with discontinuation of one of the immunosuppressive agents, i.e. rituximab, which might have led to reactivation of the virus causing necrotizing retinitis lesions. Rituximab and cyclophosphamide are extremely potent drugs, which are necessary to manage immunological disorders such as MPA. However, they may predispose the patient to serious complications like viral infections, including PORN.

Progressive trichodysplasia spinulosa in a patient with chronic lymphocytic leukaemia in remission.

PubMed

Lee, Joyce S-S; Frederiksen, Peter; Kossard, Steven

2008-02-01

A 70-year old Caucasian man with chronic lymphocytic leukaemia developed trichodysplasia spinulosa 2 months after ceasing chemotherapy. Histological features characteristic to this condition include dilated and enlarged hair follicles, hyperplastic hair bulbs, hyperplasia of inner root sheath cells with numerous large, eosinophilic, trichohyaline granules, and hypercornification. Although he was in remission for chronic lymphocytic leukaemia, lesions were slowly progressive 15 months after cessation of chemotherapy. We also describe a painless pull-test where spicules can be easily plucked and assessed microscopically for inner root sheath keratinization, or observed with surface microscopy in a clinic setting.

Definitive diagnosis of early enamel and dentin cracks based on microscopic evaluation.

PubMed

Clark, David J; Sheets, Cherilyn G; Paquette, Jacinthe M

2003-01-01

The diagnoses of cracked teeth and incomplete coronal fracture have historically been symptom based. The dental operating microscope at 16x magnification can fundamentally change a clinician's ability to diagnose such conditions. Clinicians have been observing cracks under extreme magnification for nearly a decade. Patterns have become clear that can lead to appropriate treatment prior to symptoms or to devastation to tooth structure. Conversely, many cracks are not structural and can lead to misdiagnosis and overtreatment. Methodic microscopic examination, an understanding of crack progression, and an appreciation of the types of cracks will guide a doctor to make appropriate decisions. Teeth can have structural cracks in various stages. To date, diagnosis and treatment are very often at end stage of crack development. This article gives new guidelines for recognition, visualization, classification, and treatment of cracked teeth based on the routine use of 16x magnification. The significance of enamel cracks as they relate to dentinal cracks is detailed.

Advances in Light Microscopy for Neuroscience

PubMed Central

Wilt, Brian A.; Burns, Laurie D.; Ho, Eric Tatt Wei; Ghosh, Kunal K.; Mukamel, Eran A.

2010-01-01

Since the work of Golgi and Cajal, light microscopy has remained a key tool for neuroscientists to observe cellular properties. Ongoing advances have enabled new experimental capabilities using light to inspect the nervous system across multiple spatial scales, including ultrastructural scales finer than the optical diffraction limit. Other progress permits functional imaging at faster speeds, at greater depths in brain tissue, and over larger tissue volumes than previously possible. Portable, miniaturized fluorescence microscopes now allow brain imaging in freely behaving mice. Complementary progress on animal preparations has enabled imaging in head-restrained behaving animals, as well as time-lapse microscopy studies in the brains of live subjects. Mouse genetic approaches permit mosaic and inducible fluorescence-labeling strategies, whereas intrinsic contrast mechanisms allow in vivo imaging of animals and humans without use of exogenous markers. This review surveys such advances and highlights emerging capabilities of particular interest to neuroscientists. PMID:19555292

Monitoring of biofilm aging in a Sphingomonas sp. strain from public drinking water sites through changes in capacitance.

PubMed

Gulati, Parul; Singh, Pawandeep; Chatterjee, Arun Kumar; Ghosh, Moushumi

2017-09-01

This study reports the applicability of a capacitance-based technique for evaluating the biofilm progression of Sphingomonas sp. One hundred and forty isolates of Sphingomonas were screened from public drinking water sites, and one potential strain with biofilm-forming ability was used for the study. The biofilm production by this strain was established in microtiter plates and aluminum coupons. The standard biofilm-forming strain Sphingomonas terrae MTCC 7766 was used for comparison. Changes in biofilm were analyzed by energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscope (SEM). Capacitance values were measured at 1, 100 and 200 kHz frequency; however, 1 kHz was selected since resulted in reproducible values, which could be correlated to biofilm age measured as dry weight over a time of 96 h (4 days) depicting the biofilm growth/progression over time. The EDX, SEM and capacitance values obtained in parallel indicated the related physiological profile usually displayed by biofilms upon growth, suggesting authenticity to the observed capacitance profile. The results of this study demonstrated the feasibility of a capacitance-based method for analyzing biofilm development/progression by Sphingomonas sp. and suggested a simple approach for developing an online system to detect biofilms by this opportunistic pathogen of concern in drinking water.

The oxygen isotopes

NASA Astrophysics Data System (ADS)

Alex Brown, B.

The properties of the oxygen isotopes provide diverse examples of progress made in experiments and theory. This chain of isotopes has been studied from beyond the proton drip line in 12O to beyond the neutron drip line in 25,26O. This short survey starts with the microscopic G matrix approach for 18O of Kuo and Brown in the 1960's and shows how theory has evolved. The nuclear structure around the doubly-magic nucleus 24O is particularly simple in terms of the nuclear shell model. The nuclear structure around the doubly-magic nucleus 16O exhibits the coexistence of single-particle and collective structure.

Optical coherence tomography (OCT) of a murine model of chronic kidney disease

NASA Astrophysics Data System (ADS)

Wang, Hsing-Wen; Guo, Hengchang; Andrews, Peter M.; Anderson, Erik; Chen, Y.

2015-03-01

Chronic Kidney Disease (CKD) is characterized by a progressive loss in renal function over time. Pathology can provide valuable insights into the progression of CKD by analyzing the status of glomeruli and the uriniferous tubules over time. Optical coherence tomography (OCT) is a new procedure that can analyze the microscopic structure of the kidney in a non-invasive manner. This is especially important because there are significant artifacts associated with excision biopsies and immersion fixation procedures. Recently, we have shown that OCT can provide real time images of kidney microstructure and Doppler OCT (DOCT) can image glomerular renal blood flow in vivo without administrating exogenous contrast agents. In this study, we used OCT to evaluate CKD in a model induced by intravenous Adriamycin injection into Munich-Wistar rats. We evaluated tubular density and tubular diameter from OCT images at several post- Adriamycin induction time points and compared them with conventional light microscopic histological imaging. Proteinurea and serum creatinine were used as physiological markers of the extent of CKD. Preliminary OCT results revealed changes in tubular density due to tubular necrosis and interstitial fibrosis within the first 4 weeks following Adriamycin injection. From week 4 to 8 after Adriamycin induction, changes in tubular density and diameter occurred due to both tubular loss and tubular dilation. The results suggest OCT can provide additional information about kidney histopathology in CKD. DOCT revealed reduced blood flow in some glomeruli probably as a consequence of focal glomerularsclerosis.

Physics of Neutron Star Crusts.

PubMed

Chamel, Nicolas; Haensel, Pawel

2008-01-01

The physics of neutron star crusts is vast, involving many different research fields, from nuclear and condensed matter physics to general relativity. This review summarizes the progress, which has been achieved over the last few years, in modeling neutron star crusts, both at the microscopic and macroscopic levels. The confrontation of these theoretical models with observations is also briefly discussed.

Changes in wood microstructure through progressive stages of decay

Treesearch

W. Wayne Wilcox

1968-01-01

Successive stages of decay in the sapwood of sweetgum (Liquidambar styraciflua L.), a hardwood, and of southern pine (Pinus sp.), a softwood, were observed microscopically. The white-rot fungus. Polyporus versicolor L., and the brown-rot fungus, Poria monticola Murr., were the fungi used or the observations, light microscopy, plus the techniques of polarization and...

Synchrotron-based X-ray microscopic studies for bioeffects of nanomaterials.

PubMed

Zhu, Ying; Cai, Xiaoqing; Li, Jiang; Zhong, Zengtao; Huang, Qing; Fan, Chunhai

2014-04-01

There have been increasing interests in studying biological effects of nanomaterials, which are nevertheless faced up with many challenges due to the nanoscale dimensions and unique chemical properties of nanomaterials. Synchrotron-based X-ray microscopy, an advanced imaging technology with high spatial resolution and excellent elemental specificity, provides a new platform for studying interactions between nanomaterials and living systems. In this article, we review the recent progress of X-ray microscopic studies on bioeffects of nanomaterials in several living systems including cells, model organisms, animals and plants. We aim to provide an overview of the state of the art, and the advantages of using synchrotron-based X-ray microscopy for characterizing in vitro and in vivo behaviors and biodistribution of nanomaterials. We also expect that the use of a combination of new synchrotron techniques should offer unprecedented opportunities for better understanding complex interactions at the nano-biological interface and accounting for unique bioeffects of nanomaterials. Synchrotron-based X-ray microscopy is a non-destructive imaging technique that enables high resolution spatial mapping of metals with elemental level detection methods. This review summarizes the current use and perspectives of this novel technique in studying the biology and tissue interactions of nanomaterials. Copyright © 2014 Elsevier Inc. All rights reserved.

Gliogenesis: historical perspectives, 1839-1985.

PubMed

Webster, Henry deF; Aström, Karl E

2009-01-01

This historical review of gliogenesis begins with Schwann's introduction of the cell doctrine in 1839. Subsequent microscopic studies revealed the cellular structure of many organs and tissues, but the CNS was thought to be different. In 1864, Virchow created the concept that nerve cells are held together by a "Nervenkitte" which he called"glia" (for glue). He and his contemporaries thought that "glia" was an unstructured, connective tissue-like ground substance that separated nerve cells from each other and from blood vessels. Dieters, a pupil of Virchow, discovered that this ground substance contained cells, which he described and illustrated. Improvements in microscopes and discovery of metallic impregnation methods finally showed convincingly that the "glia" was not a binding substance. Instead, it was composed of cells, each separate and distinct from neighboring cells and each with its own characteristic array of processes. Light microscopic studies of developing and mature nervous tissue led to the discovery of different types of glial cells-astroglia, oligodendroglia, microglia, and ependymal cells in the CNS, and Schwann cells in the peripheral nervous system (PNS). Subsequent studies characterized the origins and development of each type of glial cell. A new era began with the introduction of electron microscopy, immunostaining, and in vitro maintenance of both central and peripheral nervous tissue. Other methods and models greatly expanded our understanding of how glia multiply, migrate, and differentiate. In 1985, almost a century and a half of study had produced substantial progress in our understanding of glial cells, including their origins and development. Major advances were associated with the discovery of new methods. These are summarized first. Then the origins and development of astroglia, oligodendroglia, microglia, ependymal cells, and Schwann cells are described and discussed. In general, morphology is emphasized. Findings related to cytodifferentiation, cellular interactions, functions, and regulation of developing glia have also been included.

[An alternative to the usual operating microscope and loupe magnification for free microvascular tissue transfer. Varioscope AF3-A].

PubMed

Chiummariello, S; Alfano, C; Fioramonti, P; Scuderi, N

2005-12-01

Free microvascular tissue transfers have become today a key instrument for the surgical treatment of wide loss of tissue, but their employment implies mandatory use of the right visual magnification means. Until now these instruments were mainly loupes and operating microscopes. Our study is focusing on the use of a new visual system--Varioscope AF3-A--in the reconstructive microsurgery field. Varioscope AF3-A (Life Optics, Vienna, Austria) has been employed in our Institute in 10 microvascular reconstructions, where different free flaps were used in head and neck reconstruction. All the flaps took and only one developed a partial necrosis. We have also noticed, by using this new instrument, a learning curve with a progressive contraction of the operating time. In all cases we have operated on 2 mm caliber vessels or more and on tissues that didn't previously undergo radiation therapy. The employment of a visual magnification mean, as Varioscope AF3-A, allows autofocus (from 3.6X to 7.2X) and a wide vision. It can be easily used with substantial advantages for the surgeon in performing microvascular anastomosis. Partial drawbacks are the equipment high cost and weight, compared to the loupes and a stronger ocular stress due to the continuous autofocus compared to the static operating microscopes.

Assessing idiopathic pulmonary fibrosis (IPF) with bronchoscopic OCT (Conference Presentation)

NASA Astrophysics Data System (ADS)

Hariri, Lida P.; Adams, David C.; Colby, Thomas V.; Tager, Andrew M.; Suter, Melissa J.

2016-03-01

Idiopathic pulmonary fibrosis (IPF) is a progressive, fatal form of fibrotic lung disease, with a 3 year survival rate of 50%. Diagnostic certainty of IPF is essential to determine the most effective therapy for patients, but often requires surgery to resect lung tissue and look for microscopic honeycombing not seen on chest computed tomography (CT). Unfortunately, surgical lung resection has high risks of associated morbidity and mortality in this patient population. We aim to determine whether bronchoscopic optical coherence tomography (OCT) can serve as a novel, low-risk paradigm for in vivo IPF diagnosis without surgery or tissue removal. OCT provides rapid 3D visualization of large tissue volumes with microscopic resolutions well beyond the capabilities of CT. We have designed bronchoscopic OCT catheters to effectively and safely access the peripheral lung, and conducted in vivo peripheral lung imaging in patients, including those with pulmonary fibrosis. We utilized these OCT catheters to perform bronchoscopic imaging in lung tissue from patients with pulmonary fibrosis to determine if bronchoscopic OCT could successfully visualize features of IPF through the peripheral airways. OCT was able to visualize characteristic features of IPF through the airway, including microscopic honeycombing (< 1 mm diameter) not visible by CT, dense peripheral fibrosis, and spatial disease heterogeneity. These findings support the potential of bronchoscopic OCT as a minimally-invasive method for in vivo IPF diagnosis. However, future clinical studies are needed to validate these findings.

Multiscale Modelling and Analysis of Collective Decision Making in Swarm Robotics

PubMed Central

Vigelius, Matthias; Meyer, Bernd; Pascoe, Geoffrey

2014-01-01

We present a unified approach to describing certain types of collective decision making in swarm robotics that bridges from a microscopic individual-based description to aggregate properties. Our approach encompasses robot swarm experiments, microscopic and probabilistic macroscopic-discrete simulations as well as an analytic mathematical model. Following up on previous work, we identify the symmetry parameter, a measure of the progress of the swarm towards a decision, as a fundamental integrated swarm property and formulate its time evolution as a continuous-time Markov process. Contrary to previous work, which justified this approach only empirically and a posteriori, we justify it from first principles and derive hard limits on the parameter regime in which it is applicable. PMID:25369026

[Quantitative data analysis for live imaging of bone.

PubMed

Seno, Shigeto

Bone tissue is a hard tissue, it was difficult to observe the interior of the bone tissue alive. With the progress of microscopic technology and fluorescent probe technology in recent years, it becomes possible to observe various activities of various cells forming bone society. On the other hand, the quantitative increase in data and the diversification and complexity of the images makes it difficult to perform quantitative analysis by visual inspection. It has been expected to develop a methodology for processing microscopic images and data analysis. In this article, we introduce the research field of bioimage informatics which is the boundary area of biology and information science, and then outline the basic image processing technology for quantitative analysis of live imaging data of bone.

What transmission electron microscopes can visualize now and in the future.

PubMed

Müller, Shirley A; Aebi, Ueli; Engel, Andreas

2008-09-01

Our review concentrates on the progress made in high-resolution transmission electron microscopy (TEM) in the past decade. This includes significant improvements in sample preparation by quick-freezing aimed at preserving the specimen in a close-to-native state in the high vacuum of the microscope. Following advances in cold stage and TEM vacuum technology systems, the observation of native, frozen hydrated specimens has become a widely used approach. It fostered the development of computer guided, fully automated low-dose data acquisition systems allowing matched pairs of images and diffraction patterns to be recorded for electron crystallography, and the collection of entire tilt-series for electron tomography. To achieve optimal information transfer to atomic resolution, field emission electron guns combined with acceleration voltages of 200-300 kV are now routinely used. The outcome of these advances is illustrated by the atomic structure of mammalian aquaporin-O and by the pore-forming bacterial cytotoxin ClyA resolved to 12 A. Further, the Yersinia injectisome needle, a bacterial pseudopilus and the binding of phalloidin to muscle actin filaments were chosen to document the advantage of the high contrast offered by dedicated scanning transmission electron microscopy (STEM) and/or the STEM's ability to measure the mass of protein complexes and directly link this to their shape. Continued progress emerging from leading research laboratories and microscope manufacturers will eventually enable us to determine the proteome of a single cell by electron tomography, and to more routinely solve the atomic structure of membrane proteins by electron crystallography.

The dendritic spine story: an intriguing process of discovery.

PubMed

DeFelipe, Javier

2015-01-01

Dendritic spines are key components of a variety of microcircuits and they represent the majority of postsynaptic targets of glutamatergic axon terminals in the brain. The present article will focus on the discovery of dendritic spines, which was possible thanks to the application of the Golgi technique to the study of the nervous system, and will also explore the early interpretation of these elements. This discovery represents an interesting chapter in the history of neuroscience as it shows us that progress in the study of the structure of the nervous system is based not only on the emergence of new techniques but also on our ability to exploit the methods already available and correctly interpret their microscopic images.

Expansion Mini-Microscopy: An Enabling Alternative in Point-of-Care Diagnostics

PubMed Central

Zhang, Yu Shrike; Santiago, Grissel Trujillo-de; Alvarez, Mario Moisés; Schiff, Steven J.; Boyden, Edward S.; Khademhosseini, Ali

2017-01-01

Diagnostics play a significant role in health care. In the developing world and low-resource regions the utility for point-of-care (POC) diagnostics becomes even greater. This need has long been recognized, and diagnostic technology has seen tremendous progress with the development of portable instrumentation such as miniature imagers featuring low complexity and cost. However, such inexpensive devices have not been able to achieve a resolution sufficient for POC detection of pathogens at very small scales, such as single-cell parasites, bacteria, fungi, and viruses. To this end, expansion microscopy (ExM) is a recently developed technique that, by physically expanding preserved biological specimens through a chemical process, enables super-resolution imaging on conventional microscopes and improves imaging resolution of a given microscope without the need to modify the existing microscope hardware. Here we review recent advances in ExM and portable imagers, respectively, and discuss the rational combination of the two technologies, that we term expansion mini-microscopy (ExMM). In ExMM, the physical expansion of a biological sample followed by imaging on a mini-microscope achieves a resolution as high as that attainable by conventional high-end microscopes imaging non-expanded samples, at significant reduction in cost. We believe that this newly developed ExMM technique is likely to find widespread applications in POC diagnostics in resource-limited and remote regions by expanded-scale imaging of biological specimens that are otherwise not resolvable using low-cost imagers. PMID:29062977

Inquiry based learning with a virtual microscope

NASA Astrophysics Data System (ADS)

Kelley, S. P.; Sharples, M.; Tindle, A.; Villasclaras-Fernández, E.

2012-12-01

As part of newly funded initiative, the Wolfson OpenScience Laboratory, we are linking a tool for inquiry based learning, nQuire (http://www.nquire.org.uk) with the virtual microscope for Earth science (http://www.virtualmicroscope.co.uk) to allow students to undertake projects and gain from inquiry based study thin sections of rocks without the need for a laboratory with expensive petrological microscopes. The Virtual Microscope (VM) was developed for undergraduate teaching of petrology and geoscience, allowing students to explore rock hand specimens and thin sections in a browser window. The system is based on HTML5 application and allows students to scan and zoom the rocks in a browser window, view in ppl and xpl conditions, and rotate specific areas to view birefringence and pleochroism. Importantly the VM allows students to gain access to rare specimens such as Moon rocks that might be too precious to suffer loss or damage. Experimentation with such specimens can inspire the learners' interest in science and allows them to investigate relevant science questions. Yet it is challenging for learners to engage in scientific processes, as they may lack scientific investigation skills or have problems in planning their activities; for teachers, managing inquiry activities is a demanding task (Quintana et al., 2004). To facilitate the realization of inquiry activities, the VM is being integrated with the nQuire tool. nQuire is a web tool that guides and supports students through the inquiry process (Mulholland et al., 2011). Learners are encouraged to construct their own personally relevant hypothesis, pose scientific questions, and plan the method to answer them. Then, the system enables users to collect and analyze data, and share their conclusions. Teachers can monitor their students' progress through inquiries, and give them access to new parts of inquiries as they advance. By means of the integration of nQuire and the VM, inquiries that involve collecting data through a microscope can be created and supported. To illustrate the possibilities of these tools, we have designed two inquiries that engage learners in the study of Moon rock samples under the microscope, starting from general questions such as comparison of Moon rocks or determining the origin of meteorites. One is aimed at undergraduate Geology students; the second has been conceived for the general public. Science teachers can reuse these inquiries, adapt them as they need, or create completely new inquiries using nQuire's authoring tool. We will report progress and demonstrate the combination of these two on-line tools to create an open educational resource allowing educators to design and run science inquiries for Earth and planetary science in a range of settings from schools to universities. Quintana, C., Reiser, B. J., Davis, E. A., Krajcik, J., Fretz, E., Duncan, R. G., Kyza, E., et al. (2004). A scaffolding design framework for software to support science inquiry. Journal of the Learning Sciences, 13(3), 337-386. Mulholland, P., Anastopoulou, S., Collins, T., FeiBt, M., Gaved, M., Kerawalla, L., Paxton, M., et al. (2011). nQuire: Technological support for personal inquiry learning. IEEE Transactions on Learning Technologies. First published online, December 5, 2011, http://doi.ieeecomputersociety.org/10.1109/TLT.2011.32.

DOE Office of Scientific and Technical Information (OSTI.GOV)

V Yashchuk; R Conley; E Anderson

Verification of the reliability of metrology data from high quality X-ray optics requires that adequate methods for test and calibration of the instruments be developed. For such verification for optical surface profilometers in the spatial frequency domain, a modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) gratings and arrays has been suggested [1] and [2] and proven to be an effective calibration method for a number of interferometric microscopes, a phase shifting Fizeau interferometer, and a scatterometer [5]. Here we describe the details of development of binary pseudo-random multilayer (BPRML) test samples suitable for characterization of scanningmore » (SEM) and transmission (TEM) electron microscopes. We discuss the results of TEM measurements with the BPRML test samples fabricated from a WiSi2/Si multilayer coating with pseudo-randomly distributed layers. In particular, we demonstrate that significant information about the metrological reliability of the TEM measurements can be extracted even when the fundamental frequency of the BPRML sample is smaller than the Nyquist frequency of the measurements. The measurements demonstrate a number of problems related to the interpretation of the SEM and TEM data. Note that similar BPRML test samples can be used to characterize X-ray microscopes. Corresponding work with X-ray microscopes is in progress.« less

Photoemission perspective on pseudogap, superconducting fluctuations, and charge order in cuprates: a review of recent progress

NASA Astrophysics Data System (ADS)

Vishik, I. M.

2018-06-01

In the course of seeking the microscopic mechanism of superconductivity in cuprate high temperature superconductors, the pseudogap phase— the very abnormal ‘normal’ state on the hole-doped side— has proven to be as big of a quandary as superconductivity itself. Angle-resolved photoemission spectroscopy (ARPES) is a powerful tool for assessing the momentum-dependent phenomenology of the pseudogap, and recent technological developments have permitted a more detailed understanding. This report reviews recent progress in understanding the relationship between superconductivity and the pseudogap, the Fermi arc phenomena, and the relationship between charge order and pseudogap from the perspective of ARPES measurements.

Delayed diagnosis of Alport syndrome without hematuria.

PubMed

Yin-Yin, Chen; You-Ming, Peng; Yu-Mei, Liang

2014-05-01

Alport syndrome is a progressive hereditary disease caused by mutations in the genes encoding type IV collagen. Persistent microscopic hematuria is the hallmark of Alport syndrome, occurring in almost all boys according to previous reports. We report the case of a 20-year-old man presented with proteinuria but no hematuria that was initially misdiagnosed with refractory nephrotic syndrome and was eventually diagnosed with Alport syndrome following kidney and skin biopsy. During the follow-up period, he experienced a rapid progression to end-stage renal disease. Timely diagnosis of Alport syndrome is important, because patients may benefit from early intervention and avoid suffering from unnecessary nephrotoxic drug use.

Progressive outer retinal necrosis after rituximab and cyclophosphamide therapy

PubMed Central

Dogra, Mohit; Bajgai, Priya; Kumar, Ashok; Sharma, Aman

2018-01-01

We report a case of progressive outer retinal necrosis (PORN) in a patient of microscopic polyangitis (MPA), being treated with immunosuppressive drugs such as cyclophosphamide and rituximab. Her aqueous tap was positive for Varicella Zoster virus and she was treated with oral and intravitreal antivirals, along with discontinuation of one of the immunosuppressive agents, i.e. rituximab, which might have led to reactivation of the virus causing necrotizing retinitis lesions. Rituximab and cyclophosphamide are extremely potent drugs, which are necessary to manage immunological disorders such as MPA. However, they may predispose the patient to serious complications like viral infections, including PORN. PMID:29582832

Characterization of a Cardiorenal-like Syndrome in Aged Chimpanzees (Pan troglodytes).

PubMed

Chilton, J; Wilcox, A; Lammey, M; Meyer, D

2016-03-01

Cardiorenal syndrome involves disease and dysfunction of the heart that leads to progressive renal dysfunction. This study investigated the relationship between cardiac and renal disease in 91 aged chimpanzees at the Alamogordo Primate Facility by evaluation of the medical histories, metabolic parameters, functional measurements of the cardiovascular system, clinical pathology, and histopathology focused on the heart and kidney. Cardiac fibrosis was the most frequent microscopic finding in 82 of 91 animals (90%), followed by glomerulosclerosis with tubulointerstitial fibrosis in 63 of 91 (69%). Cardiac fibrosis with attendant glomerulosclerosis and tubulointerstitial fibrosis was observed in 58 of 91 animals (63%); there was a statistically significant association between the 2 conditions. As the severity of cardiac fibrosis increased, there was corresponding increase in severity of glomerulosclerosis with tubulointerstitial fibrosis. Altered metabolic, cardiovascular, and clinical pathology parameters indicative of heart and kidney failure were commonly associated with the moderate to severe microscopic changes, and concurrent heart and kidney failure were considered the cause of death. The constellation of findings in the chimpanzees were similar to cardiorenal syndrome in humans. © The Author(s) 2016.

Mushy zone modeling

NASA Astrophysics Data System (ADS)

Glicksman, Martin E.; Smith, Richard N.; Marsh, Steven P.; Kuklinski, Robert

A key element of mushy zone modeling is the description of the microscopic evolution of the lengthscales within the mushy zone and the influence of macroscopic transport processes. This paper describes some recent progress in developing a mean-field statistical theory of phase coarsening in adiabatic mushy zones. The main theoretical predictions are temporal scaling laws that indicate that average lengthscale increases as time 1/3, a self-similar distribution of mushy zone lengthscales based on spherical solid particle shapes, and kinetic rate constants which provide the dependences of the coarsening process on material parameters and the volume fraction of the solid phase. High precision thermal decay experiments are described which verify aspects of the theory in pure material mushy zones held under adiabatic conditions. The microscopic coarsening theory is then integrated within a macroscopic heat transfer model of one-dimensional alloy solidification, using the Double Integral Method. The method demonstrates an ability to predict the influence of macroscopic heat transfer on the evolution of primary and secondary dendrite arm spacings in Al-Cu alloys. Finally, some suggestions are made for future experimental and theoretical studies required in developing comprehensive solidification processing models.

Development of a reactive burn model based on an explicit viscoplastic pore collapse model

NASA Astrophysics Data System (ADS)

Bouton, E.; Lefrançois, A.; Belmas, R.

2017-01-01

The aim of this study is to develop a reactive burn model based upon a microscopic hot spot model to compute the shock-initiation of pressed TATB high explosives. Such a model has been implemented in a lagrangian hydrodynamic code. In our calculations, 8 pore radii, ranging from 40 nm to 0.63 μm, have been taken into account and the porosity fraction associated to each void radius has been deduced from the Ultra-Small-Angle X-ray Scattering measurements (USAXS) for PBX-9502. The last parameter of our model is a burn rate that depends on three variables. The first two are the reaction progress variable and the lead shock pressure, the last one is the chemical reaction site number produced in the flow and calculated by the microscopic model. This burn rate has been calibrated by fitting pressure, velocity profiles and run distances to detonation. As the computed results are in close agreement with the measured ones, this model is able to perform a wide variety of numerical simulations including single, double shock waves and the desensitization phenomenon.

Detection of erythrocytes influenced by aging and type 2 diabetes using atomic force microscope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin, Hua; Xing, Xiaobo; Zhao, Hongxia

2010-01-22

The pathophysiological changes of erythrocytes are detected at the molecular scale, which is important to reveal the onset of diseases. Type 2 diabetes is an age-related metabolic disorder with high prevalence in elderly (or old) people. Up to now, there are no treatments to cure diabetes. Therefore, early detection and the ability to monitor the progression of type 2 diabetes are very important for developing effective therapies. Type 2 diabetes is associated with high blood glucose in the context of insulin resistance and relative insulin deficiency. These abnormalities may disturb the architecture and functions of erythrocytes at molecular scale. Inmore » this study, the aging- and diabetes-induced changes in morphological and biomechanical properties of erythrocytes are clearly characterized at nanometer scale using atomic force microscope (AFM). The structural information and mechanical properties of the cell surface membranes of erythrocytes are very important indicators for determining the healthy, diseased or aging status. So, AFM may potentially be developed into a powerful tool in diagnosing diseases.« less

Characterizing absolute piezoelectric microelectromechanical system displacement using an atomic force microscope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evans, J., E-mail: radiant@ferrodevices.com; Chapman, S., E-mail: radiant@ferrodevices.com

Piezoresponse Force Microscopy (PFM) is a popular tool for the study of ferroelectric and piezoelectric materials at the nanometer level. Progress in the development of piezoelectric MEMS fabrication is highlighting the need to characterize absolute displacement at the nanometer and Ångstrom scales, something Atomic Force Microscopy (AFM) might do but PFM cannot. Absolute displacement is measured by executing a polarization measurement of the ferroelectric or piezoelectric capacitor in question while monitoring the absolute vertical position of the sample surface with a stationary AFM cantilever. Two issues dominate the execution and precision of such a measurement: (1) the small amplitude ofmore » the electrical signal from the AFM at the Ångstrom level and (2) calibration of the AFM. The authors have developed a calibration routine and test technique for mitigating the two issues, making it possible to use an atomic force microscope to measure both the movement of a capacitor surface as well as the motion of a micro-machine structure actuated by that capacitor. The theory, procedures, pitfalls, and results of using an AFM for absolute piezoelectric measurement are provided.« less

Ultrastructural characteristics of tau filaments in tauopathies: immuno-electron microscopic demonstration of tau filaments in tauopathies.

PubMed

Arima, Kunimasa

2006-10-01

The microtubule-associated protein tau aggregates into filaments in the form of neurofibrillary tangles, neuropil threads and argyrophilic grains in neurons, in the form of variable astrocytic tangles in astrocytes and in the form of coiled bodies and argyrophilic threads in oligodendrocytes. These tau filaments may be classified into two types, straight filaments or tubules with 9-18 nm diameters and "twisted ribbons" composed of two parallel aligned components. In the same disease, the fine structure of tau filaments in glial cells roughly resembles that in neurons. In sporadic tauopathies, individual tau filaments show characteristic sizes, shapes and arrangements, and therefore contribute to neuropathologic differential diagnosis. In frontotemporal dementias caused by tau gene mutations, variable filamentous profiles were observed in association with mutation sites and insoluble tau isoforms, including straight filaments or tubules, paired helical filament-like filaments, and twisted ribbons. Pre-embedding immunoelectron microscopic studies were carried out using anti-3-repeat tau and anti-4-repeat tau specific antibodies, RD3 and RD4. Straight tubules in neuronal and astrocytic Pick bodies were immunolabeled by the anti-3-repeat tau antibody. The anti-4-repeat tau antibody recognized abnormal tubules comprising neurofibrillary tangles, coiled bodies and argyrophilic threads in progressive supranuclear palsy (PSP) and corticobasal degeneration. In the pre-embedding immunoelectron microscopic study using the phosphorylated tau AT8 antibody, tuft-shaped astrocytes of PSP were found to be composed of bundles of abnormal tubules in processes and perikarya of protoplasmic astrocytes. In this study, the 3-repeat tau or 4-repeat tau epitope was detected in situ at the ultrastructural level in abnormal tubules in representative pathological lesions in Pick's disease, PSP and corticobasal degeneration.

Study on mechanical properties and damage behaviors of Kevlar fiber reinforced epoxy composites by digital image correlation technique under optical microscope

NASA Astrophysics Data System (ADS)

Gao, Xiang; Shao, Wenquan; Ji, Hongwei

2010-10-01

Kevlar fiber-reinforced epoxy (KFRE) composites are widely used in the fields of aerospace, weapon, shipping, and civil industry, due to their outstanding capabilities. In this paper, mechanical properties and damage behaviors of KFRE laminate (02/902) were tested and studied under tension condition. To precisely measure the tensile mechanical properties of the material and investigate its micro-scale damage evolution, a micro-image measuring system with in-situ tensile device was designed. The measuring system, by which the in-situ tensile test can be carried out and surface morphology evolution of the tensile specimen can be visually monitored and recorded during the process of loading, includes an ultra-long working distance zoom microscope and a in-situ tensile loading device. In this study, a digital image correlation method (DICM) was used to calculate the deformation of the tensile specimen under different load levels according to the temporal series images captured by an optical microscope and CCD camera. Then, the elastic modulus and Poisson's ratio of the KFRE was obtained accordingly. The damage progresses of the KFRE laminates were analyzed. Experimental results indicated that: (1) the KFRE laminate (02/902) is almost elastic, its failure mode is brittle tensile fracture.(2) Mechanical properties parameters of the material are as follows: elastic modulus is 14- 16GPa, and tensile ultimate stress is 450-480 Mpa respectively. (3) The damage evolution of the material is that cracks appear in epoxy matrix firstly, then, with the increasing of the tensile loading, matrix cracks add up and extend along a 45° angle direction with tensile load. Furthermore, decohesion between matrix and fibers as well as delamination occurs. Eventually, fibers break and the material is damaged.

Premature detonation of an NH₄NO₃ emulsion in reactive ground.

PubMed

Priyananda, Pramith; Djerdjev, Alex M; Gore, Jeff; Neto, Chiara; Beattie, James K; Hawkett, Brian S

2015-01-01

When NH4NO3 emulsions are used in blast holes containing pyrite, they can exothermally react with pyrite, causing the emulsion to intensively heat and detonate prematurely. Such premature detonations can inflict fatal and very costly damages. The mechanism of heating of the emulsions is not well understood though such an understanding is essential for designing safe blasting. In this study the heating of an emulsion in model blast holes was simulated by solving the heat equation. The physical factors contributing to the heating phenomenon were studied using microscopic and calorimetric methods. Microscopic studies revealed the continuous formation of a large number of gas bubbles as the reaction progressed at the emulsion-pyrite interface, which made the reacting emulsion porous. Calculations show that the increase in porosity causes the thermal conductivity of a reacting region of an emulsion column in a blast hole to decrease exponentially. This large reduction in the thermal conductivity retards heat dissipation from the reacting region causing its temperature to rise. The rise in temperature accelerates the exothermic reaction producing more heat. Simulations predict a migration of the hottest spot of the emulsion column, which could dangerously heat the primers and boosters located in the blast hole. Copyright © 2014 Elsevier B.V. All rights reserved.

Building cell models and simulations from microscope images.

PubMed

Murphy, Robert F

2016-03-01

The use of fluorescence microscopy has undergone a major revolution over the past twenty years, both with the development of dramatic new technologies and with the widespread adoption of image analysis and machine learning methods. Many open source software tools provide the ability to use these methods in a wide range of studies, and many molecular and cellular phenotypes can now be automatically distinguished. This article presents the next major challenge in microscopy automation, the creation of accurate models of cell organization directly from images, and reviews the progress that has been made towards this challenge. Copyright © 2015 Elsevier Inc. All rights reserved.

The oxygen isotopes

NASA Astrophysics Data System (ADS)

Brown, B. Alex

The properties of the oxygen isotopes provide diverse examples of progress made in experiments and theory. This chain of isotopes has been studied from beyond the proton drip line in 12O to beyond the neutron drip line in 25,26O. This short survey starts with the microscopic G matrix approach for 18O of Kuo and Brown in the 1960’s and shows how theory has evolved. The nuclear structure around the doubly-magic nucleus 24O is particularly simple in terms of the nuclear shell model. The nuclear structure around the doubly-magic nucleus 16O exhibits the coexistence of single-particle and collective structure.

Ultra-structural hair alterations in Friedreich's ataxia: A scanning electron microscopic investigation.

PubMed

Turkmenoglu, F Pinar; Kasirga, U Baran; Celik, H Hamdi

2015-08-01

Friedreich's ataxia (FRDA) is an autosomal recessive inherited disorder involving progressive damage to the central and peripheral nervous systems and cardiomyopathy. FRDA is caused by the silencing of the FXN gene and reduced levels of the encoded protein, frataxin. Frataxin is a mitochondrial protein that functions primarily in iron-sulfur cluster synthesis. Skin disorders including hair abnormalities have previously been reported in patients with mitochondrial disorders. However, to our knowledge, ultra-structural hair alterations in FRDA were not demonstrated. The purpose of this study was to determine ultra-structural alterations in the hairs of FRDA patients as well as carriers. Hair specimen from four patients, who are in different stages of the disease, and two carriers were examined by scanning electron microscope. Thin and weak hair follicles with absence of homogeneities on the cuticular surface, local damages of the cuticular layer, cuticular fractures were detected in both carriers and patients, but these alterations were much more prominent in the hair follicles of patients. In addition, erosions on the surface of the cuticle and local deep cavities just under the cuticular level were observed only in patients. Indistinct cuticular pattern, pores on the cuticular surface, and presence of concavities on the hair follicle were also detected in patients in later stages of the disease. According to our results, progression of the disease increased the alterations on hair structure. We suggest that ultra-structural alterations observed in hair samples might be due to oxidative stress caused by deficient frataxin expression in mitochondria. © 2015 Wiley Periodicals, Inc.

Mechanisms underlying progressive polyuria in familial neurohypophysial diabetes insipidus.

PubMed

Arima, H; Oiso, Y

2010-07-01

Familial neurohypophysial diabetes insipidus (FNDI), an autosomal dominant disorder, is mostly caused by mutations in the gene of neurophysin II (NPII), the carrier protein of arginine vasopressin (AVP). The analyses of knock-in mice expressing a mutant NPII that causes FNDI in humans demonstrated that polyuria progressed substantially in the absence of loss of AVP neurones. Morphological analyses revealed that inclusion bodies were present in the AVP neurones in the supraoptic nucleus and that the size and numbers of inclusion bodies gradually increased in parallel with the increases in urine volume. Electron microscopic analyses showed that aggregates existed in the endoplasmic reticulum (ER) of AVP neurones. These data suggest that cell death is not the primary cause of polyuria in FNDI, and that the aggregate formation in the ER is likely to be related to the pathogenesis of the progressive polyuria.

Characterizing lamina propria of human gastric mucosa by multiphoton microscopy

NASA Astrophysics Data System (ADS)

Liu, Y. C.; Yang, H. Q.; Chen, G.; Zhuo, S. M.; Chen, J. X.; Yan, J.

2011-01-01

Lamina propria (LP) of gastric mucosa plays an important role in progression of gastric cancer because of the site at where inflammatory reactions occur. Multiphoton imaging has been recently employed for microscopic examination of intact tissue. In this paper, using multiphoton microscopy (MPM) based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG), high resolution multiphoton microscopic images of lamina propria (LP) are obtained in normal human gastric mucosa at excitation wavelength λex = 800 nm. The main source of tissue TPEF originated from the cells of gastric glands, and loose connective tissue, collagen, produced SHG signals. Our results demonstrated that MPM can be effective for characterizing the microstructure of LP in human gastric mucosa. The findings will be helpful for diagnosing and staging early gastric cancer in the clinics.

Laser based imaging of time depending microscopic scenes with strong light emission

NASA Astrophysics Data System (ADS)

Hahlweg, Cornelius; Wilhelm, Eugen; Rothe, Hendrik

2011-10-01

Investigating volume scatterometry methods based on short range LIDAR devices for non-static objects we achieved interesting results aside the intended micro-LIDAR: the high speed camera recording of the illuminated scene of an exploding wire -intended for Doppler LIDAR tests - delivered a very effective method of observing details of objects with extremely strong light emission. As a side effect a schlieren movie is gathered without any special effort. The fact that microscopic features of short time processes with high emission and material flow might be imaged without endangering valuable equipment makes this technique at least as interesting as the intended one. So we decided to present our results - including latest video and photo material - instead of a more theoretical paper on our progress concerning the primary goal.

Division of Biological and Medical Research annual report, 1979. [Lead abstract

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosenthal, M.W.

1979-01-01

Separate abstracts were prepared for 14 of the 20 sections included in this progress report. The other 6 sections include: introductory statements by the division director; descriptions of the animal, computer, electron microscope, and radiation support facilities; a listing of the educational activities, divisional seminars, and oral presentations by staff members; and divisional staff publications. An author index to the report is included. (ERB)

Hard probes of short-range nucleon-nucleon correlations

DOE Office of Scientific and Technical Information (OSTI.GOV)

J. Arrington, D. W. Higinbotham, G. Rosner, M. Sargsian

2012-10-01

The strong interaction of nucleons at short distances leads to a high-momentum component to the nuclear wave function, associated with short-range correlations between nucleons. These short-range, high-momentum structures in nuclei are one of the least well understood aspects of nuclear matter, relating to strength outside of the typical mean-field approaches to calculating the structure of nuclei. While it is difficult to study these short-range components, significant progress has been made over the last decade in determining how to cleanly isolate short-range correlations in nuclei. We have moved from asking if such structures exist, to mapping out their strength in nucleimore » and studying their microscopic structure. A combination of several different measurements, made possible by high-luminosity and high-energy accelerators, coupled with an improved understanding of the reaction mechanism issues involved in studying these structures, has led to significant progress, and provided significant new information on the nature of these small, highly-excited structures in nuclei. We review the general issues related to short-range correlations, survey recent experiments aimed at probing these short-range structures, and lay out future possibilities to further these studies.« less

Health and Safety Research Division: Progress report, October 1, 1985-March 31, 1987

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walsh, P.J.

1987-09-01

This report summarizes the progress in our programs for the period October 1, 1985, through March 31, 1987. The division's presentations and publications represented important contributions on the forefronts of many fields. Eleven invention disclosures were filed, two patent applications submitted, and one patent issued. The company's transfers new technologies to the private sector more efficiently than in the past. The division's responsibilities to DOE under the Uranium Mill Tailings Remedial Action (UMTRA) program includes inclusion recommendations for 3100 properties. The nuclear medicine program developed new radiopharmaceuticals and radionuclide generators through clinical trials with some of our medical cooperatives. Twomore » major collaborative indoor air quality studies and a large epidemiological study of drinking water quality and human health were completed. ORNL's first scanning tunneling microscope (STM) has achieved single atom resolution and has produced some of the world's best images of single atoms on the surface of a silicon crystal. The Biological and Radiation Physics Section, designed and constructed a soft x-ray spectrometer which has exhibited a measuring efficiency that is 10,000 times higher than other equipment. 1164 refs.« less

Towards automated early cancer detection: Non-invasive, fluorescence-based approaches for quantitative assessment of cells and tissue to identify pre-cancers

NASA Astrophysics Data System (ADS)

Levitt, Jonathan Michael

Cancer is the second leading cause of death globally, second only to heart disease. As in many diseases, patient survival is directly related to how early lesions are detected. Using conventional screening methods, the early changes associated with cancer, which occur on the microscopic scale, can easily go overlooked. Due to the inherent drawbacks of conventional techniques we present non-invasive, optically based methods to acquire high resolution images from live samples and assess cellular function associated with the onset of disease. Specifically, we acquired fluorescence images from NADH and FAD to quantify morphology and metabolic activity. We first conducted studies to monitor monolayers of keratinocytes in response to apoptosis which has been shown to be disrupted during cancer progression. We found that as keratinocytes undergo apoptosis there are populations of mitochondria that exhibit a higher metabolic activity that become progressively confined to a gradually smaller perinuclear region. To further assess the changes associated with early cancer growth we developed automated methods to rapidly quantify fluorescence images and extract morphological and metabolic information from life tissue. In this study, we simultaneously quantified mitochondrial organization, metabolic activity, nuclear size distribution, and the localization of the structural protein keratin, to differentiate between normal and pre-cancerous engineered tissues. We found the degree mitochondrial organization, as determined from the fractal derived Hurst parameter, was well correlated to level of cellular differentiation. We also found that the metabolic activity in the pre-cancerous cells was greater and more consistent throughout tissue depths in comparison to normal tissue. Keratin localization, also quantified from the fluorescence images, we found it to be confined to the uppermost layers of normal tissue while it was more evenly distributed in the precancerous tissues. To allow for evaluation of the early cancerous changes in vivo, we developed video-rate confocal reflectance/multi-photon fluorescence microscope as a clinical prototype. This device was specifically designed to rapidly acquire and assess non-invasively acquire fluorescence images using the automated methods we have developed. We have demonstrated the ability of this microscope to simultaneously acquire fluorescence, confocal reflectance, and second-harmonic generation images as well as assess blood flow in vivo.

Compact, light-weight and cost-effective microscope based on lensless incoherent holography for telemedicine applications.

PubMed

Mudanyali, Onur; Tseng, Derek; Oh, Chulwoo; Isikman, Serhan O; Sencan, Ikbal; Bishara, Waheb; Oztoprak, Cetin; Seo, Sungkyu; Khademhosseini, Bahar; Ozcan, Aydogan

2010-06-07

Despite the rapid progress in optical imaging, most of the advanced microscopy modalities still require complex and costly set-ups that unfortunately limit their use beyond well equipped laboratories. In the meantime, microscopy in resource-limited settings has requirements significantly different from those encountered in advanced laboratories, and such imaging devices should be cost-effective, compact, light-weight and appropriately accurate and simple to be usable by minimally trained personnel. Furthermore, these portable microscopes should ideally be digitally integrated as part of a telemedicine network that connects various mobile health-care providers to a central laboratory or hospital. Toward this end, here we demonstrate a lensless on-chip microscope weighing approximately 46 grams with dimensions smaller than 4.2 cm x 4.2 cm x 5.8 cm that achieves sub-cellular resolution over a large field of view of approximately 24 mm(2). This compact and light-weight microscope is based on digital in-line holography and does not need any lenses, bulky optical/mechanical components or coherent sources such as lasers. Instead, it utilizes a simple light-emitting-diode (LED) and a compact opto-electronic sensor-array to record lensless holograms of the objects, which then permits rapid digital reconstruction of regular transmission or differential interference contrast (DIC) images of the objects. Because this lensless incoherent holographic microscope has orders-of-magnitude improved light collection efficiency and is very robust to mechanical misalignments it may offer a cost-effective tool especially for telemedicine applications involving various global health problems in resource limited settings.

The dendritic spine story: an intriguing process of discovery

PubMed Central

DeFelipe, Javier

2015-01-01

Dendritic spines are key components of a variety of microcircuits and they represent the majority of postsynaptic targets of glutamatergic axon terminals in the brain. The present article will focus on the discovery of dendritic spines, which was possible thanks to the application of the Golgi technique to the study of the nervous system, and will also explore the early interpretation of these elements. This discovery represents an interesting chapter in the history of neuroscience as it shows us that progress in the study of the structure of the nervous system is based not only on the emergence of new techniques but also on our ability to exploit the methods already available and correctly interpret their microscopic images. PMID:25798090

Microencapsulation of Flavors in Carnauba Wax

PubMed Central

Milanovic, Jelena; Manojlovic, Verica; Levic, Steva; Rajic, Nevenka; Nedovic, Viktor; Bugarski, Branko

2010-01-01

The subject of this study is the development of flavor wax formulations aimed for food and feed products. The melt dispersion technique was applied for the encapsulation of ethyl vanillin in wax microcapsules. The surface morphology of microparticles was investigated using scanning electron microscope (SEM), while the loading content was determined by HPLC measurements. This study shows that the decomposition process under heating proceeds in several steps: vanilla evaporation occurs at around 200 °C, while matrix degradation starts at 250 °C and progresses with maxima at around 360, 440 and 520 °C. The results indicate that carnauba wax is an attractive material for use as a matrix for encapsulation of flavours in order to improve their functionality and stability in products. PMID:22315575

Microencapsulation of flavors in carnauba wax.

PubMed

Milanovic, Jelena; Manojlovic, Verica; Levic, Steva; Rajic, Nevenka; Nedovic, Viktor; Bugarski, Branko

2010-01-01

The subject of this study is the development of flavor wax formulations aimed for food and feed products. The melt dispersion technique was applied for the encapsulation of ethyl vanillin in wax microcapsules. The surface morphology of microparticles was investigated using scanning electron microscope (SEM), while the loading content was determined by HPLC measurements. This study shows that the decomposition process under heating proceeds in several steps: vanilla evaporation occurs at around 200 °C, while matrix degradation starts at 250 °C and progresses with maxima at around 360, 440 and 520 °C. The results indicate that carnauba wax is an attractive material for use as a matrix for encapsulation of flavours in order to improve their functionality and stability in products.

Electrochemical Study of Cobalt in Urea and Choline Chloride

NASA Astrophysics Data System (ADS)

Li, Min; Shi, Zhongning; Wang, Zhaowen; Reddy, Ramana G.

The nucleation mechanism of Co(II) in urea-choline chloride-CoCl2 melt at 373 K was studied using chronoamperometry. Chronoamperometry experiments confirm that the electrodeposition of cobalt on tungsten electrode is governed by three-dimensional (3D) progressive nucleation and diffusion-controlled growth mechanisms. The average diffusion coefficient of Co(II) in the melt at 373 K is 1.1 × 10-6 cm2 s-1, which is in good agreement with the estimated value obtained from cyclic voltammetry data. Characterization of the Co electrodeposit using scanning electron microscope (SEM), energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD) techniques indicate that the electrodeposit obtained at -0.75 V and 373 K contain dense and compact surface formed from pure cobalt metal.

Squared ligament of the elbow: anatomy and contribution to forearm stability.

PubMed

Otayek, Salma; Tayeb, Abd-el-Kader Ait; Assabah, Bouchra; Viard, Brice; Dayan, Romain; Lazure, Thierry; Soubeyrand, Marc

2016-03-01

The present study describes the macroscopic and microscopic features of the squared ligament of the elbow (SLE). In addition, the SLE biomechanical behavior and contribution to the forearm stability were also examined. Ten forearms from freshly frozen cadavers were used for this work. Each forearm was mounted in an experimental frame for quantification of longitudinal and transverse stability. Macroscopic features and biomechanical behavior were analyzed on dynamic videos obtained during forearm rotation. Then, the SLE was harvested from the 10 forearms for microscopic analysis on histological slices stained with hematoxylin-eosin-saffron. Two main SLE configurations were identified. One in which the SLE had three distinct bundles (anterior, middle, posterior) and another in which it was homogeneous. The anterior part of the SLE had a mean length of 11.2 mm (±2.4 mm) and a mean width of 1.2 mm (±0.2 mm) while the posterior part had a mean length of 9.9 mm (±2.2 mm) and a mean width of 1 mm (±0.2 mm). Microscopic examination showed that the SLE is composed of a thin layer of arranged collagen fibers. During forearm rotation, the SLE progressively tightens upon pronation and supination by wrapping around the radial neck. Tightening of the SLE during forearm rotation provides transverse and longitudinal stability to the forearm, mainly in maximal pronation and supination. The SLE is a true ligament and provides forearm stability when it is stretched in pronation and supination.

Principles of Chemical Bonding and Band Gap Engineering in Hybrid Organic-Inorganic Halide Perovskites.

PubMed

Walsh, Aron

2015-03-19

The performance of solar cells based on hybrid halide perovskites has seen an unparalleled rate of progress, while our understanding of the underlying physical chemistry of these materials trails behind. Superficially, CH 3 NH 3 PbI 3 is similar to other thin-film photovoltaic materials: a semiconductor with an optical band gap in the optimal region of the electromagnetic spectrum. Microscopically, the material is more unconventional. Progress in our understanding of the local and long-range chemical bonding of hybrid perovskites is discussed here, drawing from a series of computational studies involving electronic structure, molecular dynamics, and Monte Carlo simulation techniques. The orientational freedom of the dipolar methylammonium ion gives rise to temperature-dependent dielectric screening and the possibility for the formation of polar (ferroelectric) domains. The ability to independently substitute on the A, B, and X lattice sites provides the means to tune the optoelectronic properties. Finally, ten critical challenges and opportunities for physical chemists are highlighted.

Principles of Chemical Bonding and Band Gap Engineering in Hybrid Organic–Inorganic Halide Perovskites

PubMed Central

2015-01-01

The performance of solar cells based on hybrid halide perovskites has seen an unparalleled rate of progress, while our understanding of the underlying physical chemistry of these materials trails behind. Superficially, CH3NH3PbI3 is similar to other thin-film photovoltaic materials: a semiconductor with an optical band gap in the optimal region of the electromagnetic spectrum. Microscopically, the material is more unconventional. Progress in our understanding of the local and long-range chemical bonding of hybrid perovskites is discussed here, drawing from a series of computational studies involving electronic structure, molecular dynamics, and Monte Carlo simulation techniques. The orientational freedom of the dipolar methylammonium ion gives rise to temperature-dependent dielectric screening and the possibility for the formation of polar (ferroelectric) domains. The ability to independently substitute on the A, B, and X lattice sites provides the means to tune the optoelectronic properties. Finally, ten critical challenges and opportunities for physical chemists are highlighted. PMID:25838846

Microscopic and macroscopic models for the onset and progression of Alzheimer's disease

NASA Astrophysics Data System (ADS)

Bertsch, Michiel; Franchi, Bruno; Carla Tesi, Maria; Tosin, Andrea

2017-10-01

In the first part of this paper we review a mathematical model for the onset and progression of Alzheimer’s disease (AD) that was developed in subsequent steps over several years. The model is meant to describe the evolution of AD in vivo. In Achdou et al (2013 J. Math. Biol. 67 1369-92) we treated the problem at a microscopic scale, where the typical length scale is a multiple of the size of the soma of a single neuron. Subsequently, in Bertsch et al (2017 Math. Med. Biol. 34 193-214) we concentrated on the macroscopic scale, where brain neurons are regarded as a continuous medium, structured by their degree of malfunctioning. In the second part of the paper we consider the relation between the microscopic and the macroscopic models. In particular we show under which assumptions the kinetic transport equation, which in the macroscopic model governs the evolution of the probability measure for the degree of malfunctioning of neurons, can be derived from a particle-based setting. The models are based on aggregation and diffusion equations for β-Amyloid (Aβ from now on), a protein fragment that healthy brains regularly produce and eliminate. In case of dementia Aβ monomers are no longer properly washed out and begin to coalesce forming eventually plaques. Two different mechanisms are assumed to be relevant for the temporal evolution of the disease: (i) diffusion and agglomeration of soluble polymers of amyloid, produced by damaged neurons; (ii) neuron-to-neuron prion-like transmission. In the microscopic model we consider mechanism (i), modelling it by a system of Smoluchowski equations for the amyloid concentration (describing the agglomeration phenomenon), with the addition of a diffusion term as well as of a source term on the neuronal membrane. At the macroscopic level instead we model processes (i) and (ii) by a system of Smoluchowski equations for the amyloid concentration, coupled to a kinetic-type transport equation for the distribution function of the degree of malfunctioning of the neurons. The transport equation contains an integral term describing the random onset of the disease as a jump process localized in particularly sensitive areas of the brain.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yashchuk, Valeriy V; Conley, Raymond; Anderson, Erik H

Verification of the reliability of metrology data from high quality x-ray optics requires that adequate methods for test and calibration of the instruments be developed. For such verification for optical surface profilometers in the spatial frequency domain, a modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) gratings and arrays has been suggested [Proc. SPIE 7077-7 (2007), Opt. Eng. 47(7), 073602-1-5 (2008)} and proven to be an effective calibration method for a number of interferometric microscopes, a phase shifting Fizeau interferometer, and a scatterometer [Nucl. Instr. and Meth. A 616, 172-82 (2010)]. Here we describe the details ofmore » development of binary pseudo-random multilayer (BPRML) test samples suitable for characterization of scanning (SEM) and transmission (TEM) electron microscopes. We discuss the results of TEM measurements with the BPRML test samples fabricated from a WiSi2/Si multilayer coating with pseudo randomly distributed layers. In particular, we demonstrate that significant information about the metrological reliability of the TEM measurements can be extracted even when the fundamental frequency of the BPRML sample is smaller than the Nyquist frequency of the measurements. The measurements demonstrate a number of problems related to the interpretation of the SEM and TEM data. Note that similar BPRML test samples can be used to characterize x-ray microscopes. Corresponding work with x-ray microscopes is in progress.« less

A high performance, cost-effective, open-source microscope for scanning two-photon microscopy that is modular and readily adaptable.

PubMed

Rosenegger, David G; Tran, Cam Ha T; LeDue, Jeffery; Zhou, Ning; Gordon, Grant R

2014-01-01

Two-photon laser scanning microscopy has revolutionized the ability to delineate cellular and physiological function in acutely isolated tissue and in vivo. However, there exist barriers for many laboratories to acquire two-photon microscopes. Additionally, if owned, typical systems are difficult to modify to rapidly evolving methodologies. A potential solution to these problems is to enable scientists to build their own high-performance and adaptable system by overcoming a resource insufficiency. Here we present a detailed hardware resource and protocol for building an upright, highly modular and adaptable two-photon laser scanning fluorescence microscope that can be used for in vitro or in vivo applications. The microscope is comprised of high-end componentry on a skeleton of off-the-shelf compatible opto-mechanical parts. The dedicated design enabled imaging depths close to 1 mm into mouse brain tissue and a signal-to-noise ratio that exceeded all commercial two-photon systems tested. In addition to a detailed parts list, instructions for assembly, testing and troubleshooting, our plan includes complete three dimensional computer models that greatly reduce the knowledge base required for the non-expert user. This open-source resource lowers barriers in order to equip more laboratories with high-performance two-photon imaging and to help progress our understanding of the cellular and physiological function of living systems.

A High Performance, Cost-Effective, Open-Source Microscope for Scanning Two-Photon Microscopy that Is Modular and Readily Adaptable

PubMed Central

Rosenegger, David G.; Tran, Cam Ha T.; LeDue, Jeffery; Zhou, Ning; Gordon, Grant R.

2014-01-01

Two-photon laser scanning microscopy has revolutionized the ability to delineate cellular and physiological function in acutely isolated tissue and in vivo. However, there exist barriers for many laboratories to acquire two-photon microscopes. Additionally, if owned, typical systems are difficult to modify to rapidly evolving methodologies. A potential solution to these problems is to enable scientists to build their own high-performance and adaptable system by overcoming a resource insufficiency. Here we present a detailed hardware resource and protocol for building an upright, highly modular and adaptable two-photon laser scanning fluorescence microscope that can be used for in vitro or in vivo applications. The microscope is comprised of high-end componentry on a skeleton of off-the-shelf compatible opto-mechanical parts. The dedicated design enabled imaging depths close to 1 mm into mouse brain tissue and a signal-to-noise ratio that exceeded all commercial two-photon systems tested. In addition to a detailed parts list, instructions for assembly, testing and troubleshooting, our plan includes complete three dimensional computer models that greatly reduce the knowledge base required for the non-expert user. This open-source resource lowers barriers in order to equip more laboratories with high-performance two-photon imaging and to help progress our understanding of the cellular and physiological function of living systems. PMID:25333934

Severe hypokinesis caused by paraneoplastic anti-Ma2 encephalitis associated with bilateral intratubular germ-cell neoplasm of the testes.

PubMed

Matsumoto, Lumine; Yamamoto, Tomotaka; Higashihara, Mana; Sugimoto, Izumi; Kowa, Hisatomo; Shibahara, Junji; Nakamura, Koichiro; Shimizu, Jun; Ugawa, Yoshikazu; Goto, Jun; Dalmau, Josep; Tsuji, Shoji

2007-04-15

We report a 40-year-old man with severe hypokinesis as paraneoplastic manifestation of a microscopic "carcinoma in situ" of the testis. The young age of the patient, along with progressive neurologic deterioration, detection of anti-Ma2 antibodies, and ultrasound findings of bilateral microcalcifications, led to bilateral orchiectomy, revealing the tumor in both testes. After orchiectomy, neurological symptoms stabilized, but the patient eventually died of systemic complications caused by his severe neurological deficits. Anti-Ma2 paraneoplastic encephalitis should be considered in patients with severe hypokinesis, and intensive investigation and aggressive approach to treatment is encouraged to prevent progression of the neurological deficits.

Severe Hypokinesis Caused by Paraneoplastic Anti-Ma2 Encephalitis Associated with Bilateral Intratubular Germ-Cell Neoplasm of the Testes

PubMed Central

Matsumoto, Lumine; Yamamoto, Tomotaka; Higashihara, Mana; Sugimoto, Izumi; Kowa, Hisatomo; Shibahara, Junji; Nakamura, Koichiro; Shimizu, Jun; Ugawa, Yoshikazu; Goto, Jun; Dalmau, Josep; Tsuji, Shoji

2007-01-01

We report a 40-year-old man with severe hypokinesis as paraneoplastic manifestation of a microscopic “carcinoma in situ” of the testis. The young age of the patient, along with progressive neurologic deterioration, detection of anti-Ma2 antibodies, and ultrasound findings of bilateral microcalcifications, led to bilateral orchiectomy, revealing the tumor in both testes. After orchiectomy, neurological symptoms stabilized, but the patient eventually died of systemic complications caused by his severe neurological deficits. Anti-Ma2 paraneoplastic encephalitis should be considered in patients with severe hypokinesis, and intensive investigation and aggressive approach to treatment is encouraged to prevent progression of the neurological deficits. PMID:17269131

An automated image processing routine for segmentation of cell cytoplasms in high-resolution autofluorescence images

NASA Astrophysics Data System (ADS)

Walsh, Alex J.; Skala, Melissa C.

2014-02-01

The heterogeneity of genotypes and phenotypes within cancers is correlated with disease progression and drug-resistant cellular sub-populations. Therefore, robust techniques capable of probing majority and minority cell populations are important both for cancer diagnostics and therapy monitoring. Herein, we present a modified CellProfiler routine to isolate cytoplasmic fluorescence signal on a single cell level from high resolution auto-fluorescence microscopic images.

Connexin composition in apposed gap junction hemiplaques revealed by matched double-replica freeze-fracture replica immunogold labeling.

PubMed

Rash, John E; Kamasawa, Naomi; Davidson, Kimberly G V; Yasumura, Thomas; Pereda, Alberto E; Nagy, James I

2012-06-01

Despite the combination of light-microscopic immunocytochemistry, histochemical mRNA detection techniques and protein reporter systems, progress in identifying the protein composition of neuronal versus glial gap junctions, determination of the differential localization of their constituent connexin proteins in two apposing membranes and understanding human neurological diseases caused by connexin mutations has been problematic due to ambiguities introduced in the cellular and subcellular assignment of connexins. Misassignments occurred primarily because membranes and their constituent proteins are below the limit of resolution of light microscopic imaging techniques. Currently, only serial thin-section transmission electron microscopy and freeze-fracture replica immunogold labeling have sufficient resolution to assign connexin proteins to either or both sides of gap junction plaques. However, freeze-fracture replica immunogold labeling has been limited because conventional freeze fracturing allows retrieval of only one of the two membrane fracture faces within a gap junction, making it difficult to identify connexin coupling partners in hemiplaques removed by fracturing. We now summarize progress in ascertaining the connexin composition of two coupled hemiplaques using matched double-replicas that are labeled simultaneously for multiple connexins. This approach allows unambiguous identification of connexins and determination of the membrane "sidedness" and the identities of connexin coupling partners in homotypic and heterotypic gap junctions of vertebrate neurons.

Electron microscopic studies of mitosis in amebae. I. Amoeba proteus.

PubMed

ROTH, L E; OBETZ, S W; DANIELS, E W

1960-09-01

Individual organisms of Amoeba proteus have been fixed in buffered osmium tetroxide in either 0.9 per cent NaCl or 0.01 per cent CaCl(2), sectioned, and studied in the electron microscope in interphase and in several stages of mitosis. The helices typical of interphase nuclei do not coexist with condensed chromatin and thus either represent a DNA configuration unique to interphase or are not DNA at all. The membranes of the complex nuclear envelope are present in all stages observed but are discontinuous in metaphase. The inner, thick, honeycomb layer of the nuclear envelope disappears during prophase, reappearing after telophase when nuclear reconstruction is in progress. Nucleoli decrease in size and number during prophase and re-form during telophase in association with the chromatin network. In the early reconstruction nucleus, the nucleolar material forms into thin, sheet-like configurations which are closely associated with small amounts of chromatin and are closely applied to the inner, partially formed layer of the nuclear envelope. It is proposed that nucleolar material is implicated in the formation of the inner layer of the envelope and that there is a configuration of nucleolar material peculiar to this time. The plasmalemma is partially denuded of its fringe-like material during division.

ELECTRON MICROSCOPIC STUDIES OF MITOSIS IN AMEBAE

PubMed Central

Roth, L. E.; Obetz, S. W.; Daniels, E. W.

1960-01-01

Individual organisms of Amoeba proteus have been fixed in buffered osmium tetroxide in either 0.9 per cent NaCl or 0.01 per cent CaCl2, sectioned, and studied in the electron microscope in interphase and in several stages of mitosis. The helices typical of interphase nuclei do not coexist with condensed chromatin and thus either represent a DNA configuration unique to interphase or are not DNA at all. The membranes of the complex nuclear envelope are present in all stages observed but are discontinuous in metaphase. The inner, thick, honeycomb layer of the nuclear envelope disappears during prophase, reappearing after telophase when nuclear reconstruction is in progress. Nucleoli decrease in size and number during prophase and re-form during telophase in association with the chromatin network. In the early reconstruction nucleus, the nucleolar material forms into thin, sheet-like configurations which are closely associated with small amounts of chromatin and are closely applied to the inner, partially formed layer of the nuclear envelope. It is proposed that nucleolar material is implicated in the formation of the inner layer of the envelope and that there is a configuration of nucleolar material peculiar to this time. The plasmalemma is partially denuded of its fringe-like material during division. PMID:13743845

Breathing new life into old collections - revitalising Geoscience Australia Microscope Slide Based collections through the use of Citizen Science

NASA Astrophysics Data System (ADS)

Bastrakova, I.; Pring, J.; Blewett, R.; Champion, D. C.; Poignand, B.; Raymond, O.; Evans, N.; Stewart, A.; Butler, P.

2017-12-01

Since soon after the federation of Australia in 1901 Geoscience Australia, and its predecessors organisations, have gathered a significant collection of microscope slide based items (including: thin sections of rock, micro and nano fossils) from across Australia, Antarctica, Papua New Guinea, the Asia Pacific region and beyond. The samples from which the microscope slides were produced have been gathered via extensive geological mapping programs, work conducted for major Commonwealth building initiatives such as the Snowy Mountain Scheme and science expeditions. The cost of recreating this collection, if at all possible, would be measured in the $100Ms (AUS) even assuming that it was still possible to source the relevant samples. While access to these microscope slides is open to industry, educational institutions and the public it has not been easy to locate specific slides due to the management system. The management of this collection was based largely on an aged card catalogue and ledger system. The fragmented nature of the management system with the increasing potential for the deterioration of physical media and the loss of access to even some of the original contributors meant that rescue work was (and still is) needed urgently. Achieving progress on making the microscope slides discoverable and accessible in the current fiscally constrained environment dictated a departure from what might be considered a traditional approach to the project and saw the extensive use of a citizen science approach. Through the use of a citizen science approach the proof of concept project has seen the transcription of some 35,000 sample metadata and data records (2.5 times our current electronic holdings) from a variety of hardcopy sources by a diverse group of volunteers. The availability of this data has allowed for the electronic discovery of both the microscope slides and their parent samples, and will hopefully lead to a greater utilisation of this valuable resource and enable new geoscientific insights from old resources.

3D image restoration for confocal microscopy: toward a wavelet deconvolution for the study of complex biological structures

NASA Astrophysics Data System (ADS)

Boutet de Monvel, Jacques; Le Calvez, Sophie; Ulfendahl, Mats

2000-05-01

Image restoration algorithms provide efficient tools for recovering part of the information lost in the imaging process of a microscope. We describe recent progress in the application of deconvolution to confocal microscopy. The point spread function of a Biorad-MRC1024 confocal microscope was measured under various imaging conditions, and used to process 3D-confocal images acquired in an intact preparation of the inner ear developed at Karolinska Institutet. Using these experiments we investigate the application of denoising methods based on wavelet analysis as a natural regularization of the deconvolution process. Within the Bayesian approach to image restoration, we compare wavelet denoising with the use of a maximum entropy constraint as another natural regularization method. Numerical experiments performed with test images show a clear advantage of the wavelet denoising approach, allowing to `cool down' the image with respect to the signal, while suppressing much of the fine-scale artifacts appearing during deconvolution due to the presence of noise, incomplete knowledge of the point spread function, or undersampling problems. We further describe a natural development of this approach, which consists of performing the Bayesian inference directly in the wavelet domain.

On the Antiquity of Cancer: Evidence for Metastatic Carcinoma in a Young Man from Ancient Nubia (c. 1200BC)

PubMed Central

Binder, Michaela; Roberts, Charlotte; Spencer, Neal; Antoine, Daniel; Cartwright, Caroline

2014-01-01

Cancer, one of the world’s leading causes of death today, remains almost absent relative to other pathological conditions, in the archaeological record, giving rise to the conclusion that the disease is mainly a product of modern living and increased longevity. This paper presents a male, young-adult individual from the archaeological site of Amara West in northern Sudan (c. 1200BC) displaying multiple, mainly osteolytic, lesions on the vertebrae, ribs, sternum, clavicles, scapulae, pelvis, and humeral and femoral heads. Following radiographic, microscopic and scanning electron microscopic (SEM) imaging of the lesions, and a consideration of differential diagnoses, a diagnosis of metastatic carcinoma secondary to an unknown soft tissue cancer is suggested. This represents the earliest complete example in the world of a human who suffered metastatic cancer to date. The study further draws its strength from modern analytical techniques applied to differential diagnoses and the fact that it is firmly rooted within a well-documented archaeological and historical context, thus providing new insights into the history and antiquity of the disease as well as its underlying causes and progression. PMID:24637948

A high throughput array microscope for the mechanical characterization of biomaterials

NASA Astrophysics Data System (ADS)

Cribb, Jeremy; Osborne, Lukas D.; Hsiao, Joe Ping-Lin; Vicci, Leandra; Meshram, Alok; O'Brien, E. Tim; Spero, Richard Chasen; Taylor, Russell; Superfine, Richard

2015-02-01

In the last decade, the emergence of high throughput screening has enabled the development of novel drug therapies and elucidated many complex cellular processes. Concurrently, the mechanobiology community has developed tools and methods to show that the dysregulation of biophysical properties and the biochemical mechanisms controlling those properties contribute significantly to many human diseases. Despite these advances, a complete understanding of the connection between biomechanics and disease will require advances in instrumentation that enable parallelized, high throughput assays capable of probing complex signaling pathways, studying biology in physiologically relevant conditions, and capturing specimen and mechanical heterogeneity. Traditional biophysical instruments are unable to meet this need. To address the challenge of large-scale, parallelized biophysical measurements, we have developed an automated array high-throughput microscope system that utilizes passive microbead diffusion to characterize mechanical properties of biomaterials. The instrument is capable of acquiring data on twelve-channels simultaneously, where each channel in the system can independently drive two-channel fluorescence imaging at up to 50 frames per second. We employ this system to measure the concentration-dependent apparent viscosity of hyaluronan, an essential polymer found in connective tissue and whose expression has been implicated in cancer progression.

Confocal laser scanning microscopy in study of bone calcification

NASA Astrophysics Data System (ADS)

Nishikawa, Tetsunari; Kokubu, Mayu; Kato, Hirohito; Imai, Koichi; Tanaka, Akio

2012-12-01

Bone regeneration in mandible and maxillae after extraction of teeth or tumor resection and the use of rough surface implants in bone induction must be investigated to elucidate the mechanism of calcification. The calcified tissues are subjected to chemical decalcification or physical grinding to observe their microscopic features with light microscopy and transmission electron microscopy where the microscopic tissue morphology is significantly altered. We investigated the usefulness of confocal laser scanning microscopy (CLSM) for this purpose. After staggering the time of administration of calcein and alizarin red to experimental rats and dogs, rat alveolar bone and dog femur grafted with coral as scaffold or dental implants were observed with CLSM. In rat alveolar bone, the calcification of newly-formed bone and net-like canaliculi was observed at the mesial bone from the roots progressed at the rate of 15 μm/day. In dog femur grafted with coral, newly-formed bones along the space of coral were observed in an orderly manner. In dog femur with dental implants, after 8 weeks, newly-formed bone proceeded along the rough surface of the implants. CLSM produced high-magnification images of newly-formed bone and thin sections were not needed.

Fibrin gel as a scaffold for skin substitute – production and clinical experience.

PubMed

Kljenak, Antun; Tominac Trcin, Mirna; Bujić, Marina; Dolenec, Tamara; Jevak, Martina; Mršić, Gordan; Zmiš, Gordana; Barčot, Zoran; Muljačić, Ante; Popović, Maja

2016-06-01

The purpose of this study was to create a fibrin-based human skin substitute in vitro with epidermal and dermal component and to assess its healing potential in deep partial and full thickness burns. Fibrin scaffolds were prepared from commercial fibrin glue kits. Human fibroblasts were cultured in fibrin gel. Human keratinocytes were seeded on the top of the gel. Viability of cells was determined fluorimetrically. Scanning electron microscope and immunocytochemistry analysis of cultured cells were performed. After hydrosurgical preparation of deep burn necrotic tissue, wound bed was prepared for skin substitutes. Progress of healing was documented using visual estimation and photos. Scanning electron microscope images showed good cell attachment and colony spreading of keratinocytes and fibroblasts on fibrin scaff old. Immunofluorescent staining of cell cultures on fibrin scaffold showed expression of vimentin, a marker of fibroblast cells, cytokeratin 19, a marker of epithelial stem cells, as well as involucrin, a marker of differentiated keratinocytes. Clinical results clearly showed that appearance of the skin did not differ significantly from the areas of transplanted skin using split-thickness skin graft techniques. In conclusion, using these fibrin-cultured autografts on massive full-thickness burn resulted in good healing.

Introduction to magnification in endodontics.

PubMed

Arens, Donald E

2003-01-01

Dentistry has recently recognized the practicality and benefits of treating damaged and diseased oral tissues under high magnification levels. Initially, enhanced vision was more-or-less restricted to the use of prescription bifocals, awkward magnifying loops, and heavy cumbersome telephoto glasses; the microscope drew little interest and was quickly viewed as another useless and expensive dental gadget. However, owing to the very nature and demands of the therapy, endodontists were quick to accept and adopt this technology, and the manufacturers were quick to adapt and market their surgical microscopes to the endodontic office. Since acceptance leads to progression, we are currently witnessing manufacturers adapting the microscopic and other magnifying lenses to other areas of dentistry. However, choosing and purchasing a microscope involves a great number of issues, including the adequacy of one's present vision, the type of practice conducted, the demands one places on the quality of his or her dentistry, and the amount of time and expense one wishes to devote to becoming competent in using magnification. In addition, one must become familiar with what the different levels of magnification offer, what different depths and widths of field meet their normal practice needs, the amount of space required for the equipment, and whether the investment is cost effective. This article details all of the benefits as well as the difficulties encountered when embarking on a magnification journey. The art of dentistry is based on precision. The human naked eye is capable of distinguishing fine detail, but it is no match for what can be accomplished when an image is sharpened and enlarged. The microscope and other forms of magnification fill that need, especially for accomplishing endodontic procedures.

A deep learning framework to discern and count microscopic nematode eggs.

PubMed

Akintayo, Adedotun; Tylka, Gregory L; Singh, Asheesh K; Ganapathysubramanian, Baskar; Singh, Arti; Sarkar, Soumik

2018-06-14

In order to identify and control the menace of destructive pests via microscopic image-based identification state-of-the art deep learning architecture is demonstrated on the parasitic worm, the soybean cyst nematode (SCN), Heterodera glycines. Soybean yield loss is negatively correlated with the density of SCN eggs that are present in the soil. While there has been progress in automating extraction of egg-filled cysts and eggs from soil samples counting SCN eggs obtained from soil samples using computer vision techniques has proven to be an extremely difficult challenge. Here we show that a deep learning architecture developed for rare object identification in clutter-filled images can identify and count the SCN eggs. The architecture is trained with expert-labeled data to effectively build a machine learning model for quantifying SCN eggs via microscopic image analysis. We show dramatic improvements in the quantification time of eggs while maintaining human-level accuracy and avoiding inter-rater and intra-rater variabilities. The nematode eggs are correctly identified even in complex, debris-filled images that are often difficult for experts to identify quickly. Our results illustrate the remarkable promise of applying deep learning approaches to phenotyping for pest assessment and management.

Oral paracoccidioidomycosis or squamous cell carcinoma?

PubMed

Kaminagakura, Estela; Graner, Edgard; de Almeida, Oslei Paes; Di Hipolito Júnior, Osvaldo; Lopes, Marcio Ajudarte

2004-01-01

Paracoccidioidomycosis is a deep, systemic, and progressive mycosis caused by Paracoccidioides brasiliensis. Oral lesions normally are multiples with a mulberry-like appearance. This article reviews an unusual case involving a chronic, solitary, and ulcerated lesion whose clinical aspects were similar to squamous cell carcinoma. Viewed microscopically, the lesion showed pseudoepitheliomatous hyperplasia and non-necrotizing granulomas. The patient was treated with systemic ketoconazole. Over the next 11 years, follow-up examinations were performed but no recurrence was observed.

Angular particle impingement studies of thermoplastic materials at normal incidence

NASA Technical Reports Server (NTRS)

Rao, P. V.; Buckley, D. H.

1985-01-01

Scanning electron microscope studies were conducted to characterize the erosion resistance of polymethyl methacrylate (PMMA), polycarbonate (PC), polytetrafluorethylene (PTFE), and ultra-high-molecular-weight polyethylene (UHMWPE). Erosion was caused by a jet of angular microparticles of crushed glass at normal incidence. Material built up above the original surface on all of the materials. As erosion progressed, this buildup disappeared. UHMWPE was the most resistant material and PMMA the least. The most favorable properties for high erosion resistance were high values of ultimate elongation, maximum service temperature, and strain energy and a low value of the modulus of elasticity. Erosion-rate-versus-time curves of PC and PTFE exhibited incubation, acceleration, and steady-state periods. PMMA also exhibited a deceleration period, and an incubation period with deposition was observed for UHMWPE.

Nd:YAG laser ablation and acid resistance of enamel.

PubMed

Kwon, Yong Hoon; Kwon, Oh-Won; Kim, Hyung-Il; Kim, Kyo-Han

2003-09-01

The acid resistance of Nd:YAG laser-ablated enamel surfaces was studied by evaluating crystal structure, mineral distribution, and fluorescence radiance and image in the present study. For comparison, 37% phosphoric acid etching was performed. The formation of beta-tricalcium phosphate (beta-TCP) was confirmed in the laser-ablated surface. The Ca/P ratio increased after ablation due to mineral re-distribution. In contrast, the Ca/P ratio decreased after acid etching due to mineral loss. The laser-ablated enamels showed a smaller increase of fluorescence radiances and less clear laser confocal scanning microscope images than those observed in the acid-etched enamels. The former suggests a minimized mineral loss. The Nd:YAG laser irradiation will enhance the acid resistance and retard the carious progression in enamel.

Stochastic Processes in Physics: Deterministic Origins and Control

NASA Astrophysics Data System (ADS)

Demers, Jeffery

Stochastic processes are ubiquitous in the physical sciences and engineering. While often used to model imperfections and experimental uncertainties in the macroscopic world, stochastic processes can attain deeper physical significance when used to model the seemingly random and chaotic nature of the underlying microscopic world. Nowhere more prevalent is this notion than in the field of stochastic thermodynamics - a modern systematic framework used describe mesoscale systems in strongly fluctuating thermal environments which has revolutionized our understanding of, for example, molecular motors, DNA replication, far-from equilibrium systems, and the laws of macroscopic thermodynamics as they apply to the mesoscopic world. With progress, however, come further challenges and deeper questions, most notably in the thermodynamics of information processing and feedback control. Here it is becoming increasingly apparent that, due to divergences and subtleties of interpretation, the deterministic foundations of the stochastic processes themselves must be explored and understood. This thesis presents a survey of stochastic processes in physical systems, the deterministic origins of their emergence, and the subtleties associated with controlling them. First, we study time-dependent billiards in the quivering limit - a limit where a billiard system is indistinguishable from a stochastic system, and where the simplified stochastic system allows us to view issues associated with deterministic time-dependent billiards in a new light and address some long-standing problems. Then, we embark on an exploration of the deterministic microscopic Hamiltonian foundations of non-equilibrium thermodynamics, and we find that important results from mesoscopic stochastic thermodynamics have simple microscopic origins which would not be apparent without the benefit of both the micro and meso perspectives. Finally, we study the problem of stabilizing a stochastic Brownian particle with feedback control, and we find that in order to avoid paradoxes involving the first law of thermodynamics, we need a model for the fine details of the thermal driving noise. The underlying theme of this thesis is the argument that the deterministic microscopic perspective and stochastic mesoscopic perspective are both important and useful, and when used together, we can more deeply and satisfyingly understand the physics occurring over either scale.

In vivo multiphoton kinetic imaging of the toxic effect of carbon tetrachloride on hepatobiliary metabolism.

PubMed

Lin, Chih-Ju; Lee, Sheng-Lin; Lee, Hsuan-Shu; Dong, Chen-Yuan

2018-06-01

We used intravital multiphoton microscopy to study the recovery of hepatobiliary metabolism following carbon tetrachloride (CCl4) induced hepatotoxicity in mice. The acquired images were processed by a first order kinetic model to generate rate constant resolved images of the mouse liver. We found that with progression of hepatotoxicity, the spatial gradient of hepatic function disappeared. A CCl4-induced damage mechanism involves the compromise of membrane functions, resulting in accumulation of processed 6-carboxyfluorescein molecules. At day 14 following induction, a restoration of the mouse hepatobiliary function was found. Our approach allows the study of the response of hepatic functions to chemical agents in real time and is useful for studying pharmacokinetics of drug molecules through optical microscopic imaging. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

An experimental model of ectropion uveae and iris neovascularization in the cat.

PubMed

Hjelmeland, L M; Stewart, M W; Li, J; Toth, C A; Burns, M S; Landers, M B

1992-04-01

Neovascularization of the iris (NVI) is one of the most frequently studied intraocular vascular proliferations in animal models. Ectropion uveae has not been a consistent finding in these studies. In this study, a surgical model of ectropion uveae and iris neovascularization was developed that involved lensectomy, vitrectomy, bipolar cautery and transection of all three principal branch veins in the cat eye. Twelve of 14 eyes that received this procedure developed postoperative retinal detachments with a clinical picture of hemorrhagic retinopathy. These eyes progressed to a clinical picture of NVI within 1-7 wk. Eight eyes developed ectropion uveae for as much as 300 degrees. At the light microscopic level, a fibrovascular membrane was apparent on the anterior iris stroma in 9 of 14 eyes and further involved the angle in six eyes.

Re-recognition of Age-dependent Reference Range for the Serum Creatinine Level in Teenagers - A Case of Slowly Progressive Tubulointerstitial Nephritis which Occurred in an Adolescent.

PubMed

Ono, Hiroyuki; Nagai, Kojiro; Shibata, Eriko; Matsuura, Motokazu; Kishi, Seiji; Inagaki, Taizo; Minato, Masanori; Yoshimoto, Sakiya; Ueda, Sayo; Obata, Fumiaki; Nishimura, Kenji; Tamaki, Masanori; Kishi, Fumi; Murakami, Taichi; Abe, Hideharu; Kinoshita, Yukiko; Urushihara, Maki; Kagami, Shoji; Doi, Toshio

2017-08-15

For the first time, a 15-year-old boy was found to have a slight degree of proteinuria and microscopic hematuria during annual school urinalysis screening. His kidney function had already severely deteriorated. A kidney biopsy revealed tubulointerstitial nephritis (TIN) with diffuse inflammatory cell infiltration. His medical records showed his serum creatinine level to be 0.98 mg/dL two years ago, which was abnormally high considering his age. Although the etiology of slowly progressive TIN was unclear, glucocorticoid and immunosuppressant therapy improved his kidney function. This case report suggests that all doctors should recognize the reference range for the serum creatinine level in teenagers.

Re-recognition of Age-dependent Reference Range for the Serum Creatinine Level in Teenagers - A Case of Slowly Progressive Tubulointerstitial Nephritis which Occurred in an Adolescent -

PubMed Central

Ono, Hiroyuki; Nagai, Kojiro; Shibata, Eriko; Matsuura, Motokazu; Kishi, Seiji; Inagaki, Taizo; Minato, Masanori; Yoshimoto, Sakiya; Ueda, Sayo; Obata, Fumiaki; Nishimura, Kenji; Tamaki, Masanori; Kishi, Fumi; Murakami, Taichi; Abe, Hideharu; Kinoshita, Yukiko; Urushihara, Maki; Kagami, Shoji; Doi, Toshio

2017-01-01

For the first time, a 15-year-old boy was found to have a slight degree of proteinuria and microscopic hematuria during annual school urinalysis screening. His kidney function had already severely deteriorated. A kidney biopsy revealed tubulointerstitial nephritis (TIN) with diffuse inflammatory cell infiltration. His medical records showed his serum creatinine level to be 0.98 mg/dL two years ago, which was abnormally high considering his age. Although the etiology of slowly progressive TIN was unclear, glucocorticoid and immunosuppressant therapy improved his kidney function. This case report suggests that all doctors should recognize the reference range for the serum creatinine level in teenagers. PMID:28781321

Assessing idiopathic pulmonary fibrosis (IPF) with bronchoscopic OCT (Conference Presentation)

NASA Astrophysics Data System (ADS)

Hariri, Lida P.; Adams, David C.; Colby, Thomas V.; Tager, Andrew M.; Suter, Melissa J.

2016-03-01

Idiopathic pulmonary fibrosis (IPF) is a progressive, fatal form of fibrotic lung disease, with a significantly worse prognosis than other forms of pulmonary fibrosis (3-year survival rate of 50%). Distinguishing IPF from other fibrotic diseases is essential to patient care because it stratifies prognosis and therapeutic decision-making. However, making the diagnosis often requires invasive, high-risk surgical procedures to look for microscopic features not seen on chest CT, such as characteristic cystic honeycombing in the peripheral lung. Optical coherence tomography (OCT) provides rapid 3D visualization of large tissue volumes with microscopic resolutions well beyond the capabilities of CT. We aim to determine whether bronchoscopic OCT can provide a low-risk, non-surgical method for IPF diagnosis. We have developed bronchoscopic OCT catheters that access the peripheral lung and conducted in vivo peripheral lung imaging in patients, including those with pulmonary fibrosis. We also conducted bronchoscopic OCT in ex vivo lung from pulmonary fibrosis patients, including IPF, to determine if OCT could successfully visualize features of IPF through the peripheral airways. Our results demonstrate that OCT is able to visualize characteristic features of IPF through the airway, including microscopic honeycombing (< 1 mm diameter) not visible by CT, dense peripheral fibrosis, and spatial disease heterogeneity. We also found that OCT has potential to distinguish mimickers of IPF honeycombing, such as traction bronchiectasis and emphysema, from true honeycombing. These findings support the potential of bronchoscopic OCT as a minimally-invasive method for in vivo IPF diagnosis. However, future clinical studies are needed to validate these findings.

Forgotten research from 19th century: science should not follow fashion.

PubMed

Galler, Stefan

2015-02-01

The fine structure of cross-striated muscle and its changes during contraction were known already in considerable detail in the 19th century. This knowledge was the result of studying birefringence properties of muscle fibres under the polarization microscope, a method mainly established by Brücke (Denk Kais Akad Wiss Math Naturwiss Cl 15:69-84, 1858) in Vienna, Austria. The knowledge was seemingly forgotten in the first half of the 20th century before it was rediscovered in 1954. This rediscovery was essential for the formulation of the sliding filament theory which represents the commonly accepted concept of muscle contraction (A.F. Huxley and Niedergerke, Nature 173:971-973, 1954; H.E. Huxley and Hanson, Nature 173:973-976, 1954). The loss of knowledge was the result of prevailing views within the scientific community which could be attributed to "fashion": it was thought that the changes of cross-striations, which were observed under the microscope, were inconsequential for contraction since other types of movements like cell crawling and smooth muscle contraction were not associated with similar changes of the fine structure. The basis for this assumption was the view that all types of movements associated with life must be caused by the same mechanisms. Furthermore, it was assumed that the light microscopy was of little use, because the individual molecules that carry out life functions cannot be seen under the light microscope. This unfortunate episode of science history teaches us that the progress of science can severely be retarded by fashion.

[Autopsy case of Lissauer's general paresis with rapidly progressive left hemiparesis].

PubMed

Kato, Hiroko; Yoshida, Mari; Ando, Tetsuo; Sugiura, Makoto; Hashizume, Yoshio

2009-06-01

A 48-years-old man presented with slowly progressive bradykinesia, personality change and rapidly progressive left hemiparesis. On admission, he presented dementia, poor judgment, left hemiparesis. MRI revealed a widespread high intensity area in right hemisphere and MRA was almost normal. Serological tests of serum and CSF demonstrated high titers of antibodies to Treponema pallidum. He was treated for syphilis with daily penicillin injections without improvement. He died of sepsis eight months after admission. At autopsy, the brain weighed 1,100 g and the right cerebral hemisphere was atrophic, especially in frontal base, temporal, parietal, angular, and posterior regions covered by thickened, fibrotic leptomeninges. Microscopically, chronic meningoencephalitis was observed. Severe neuronal loss with gliosis was seen in the right cerebral cortices. Scattered rod-shaped microglia and inflammatory cell infiltration were visible in the cerebral parenchyma. The dorsal column of the spinal cord was not involved and meningovascular syphilis was unclear. The distribution of the encephalitic lesions was well correlated with the clinical and neuroradiological findings. This was a rare autopsy case presenting Lissauer's general paresis, clinically manifesting as rapidly progressive stroke-like episode.

Energy density functional on a microscopic basis

NASA Astrophysics Data System (ADS)

Baldo, M.; Robledo, L.; Schuck, P.; Viñas, X.

2010-06-01

In recent years impressive progress has been made in the development of highly accurate energy density functionals, which allow us to treat medium-heavy nuclei. In this approach one tries to describe not only the ground state but also the first relevant excited states. In general, higher accuracy requires a larger set of parameters, which must be carefully chosen to avoid redundancy. Following this line of development, it is unavoidable that the connection of the functional with the bare nucleon-nucleon interaction becomes more and more elusive. In principle, the construction of a density functional from a density matrix expansion based on the effective nucleon-nucleon interaction is possible, and indeed the approach has been followed by few authors. However, to what extent a density functional based on such a microscopic approach can reach the accuracy of the fully phenomenological ones remains an open question. A related question is to establish which part of a functional can be actually derived by a microscopic approach and which part, in contrast, must be left as purely phenomenological. In this paper we discuss the main problems that are encountered when the microscopic approach is followed. To this purpose we will use the method we have recently introduced to illustrate the different aspects of these problems. In particular we will discuss the possible connection of the density functional with the nuclear matter equation of state and the distinct features of finite-size effect typical of nuclei.

To understand coral disease, look at coral cells

USGS Publications Warehouse

Work, Thierry M.; Meteyer, Carol U.

2014-01-01

Diseases threaten corals globally, but 40 years on their causes remain mostly unknown. We hypothesize that inconsistent application of a complete diagnostic approach to coral disease has contributed to this slow progress. We quantified methods used to investigate coral disease in 492 papers published between 1965 and 2013. Field surveys were used in 65% of the papers, followed by biodetection (43%), laboratory trials (20%), microscopic pathology (21%), and field trials (9%). Of the microscopic pathology efforts, 57% involved standard histopathology at the light microscopic level (12% of the total investigations), with the remainder dedicated to electron or fluorescence microscopy. Most (74%) biodetection efforts focused on culture or molecular characterization of bacteria or fungi from corals. Molecular and immunological tools have been used to incriminate infectious agents (mainly bacteria) as the cause of coral diseases without relating the agent to specific changes in cell and tissue pathology. Of 19 papers that declared an infectious agent as a cause of disease in corals, only one (5%) used microscopic pathology, and none fulfilled all of the criteria required to satisfy Koch’s postulates as applied to animal diseases currently. Vertebrate diseases of skin and mucosal surfaces present challenges similar to corals when trying to identify a pathogen from a vast array of environmental microbes, and diagnostic approaches regularly used in these cases might provide a model for investigating coral diseases. We hope this review will encourage specialists of disease in domestic animals, wildlife, fish, shellfish, and humans to contribute to the emerging field of coral disease.

Fano Description of Single-Hydrocarbon Fluorescence Excited by a Scanning Tunneling Microscope.

PubMed

Kröger, Jörg; Doppagne, Benjamin; Scheurer, Fabrice; Schull, Guillaume

2018-06-13

The detection of fluorescence with submolecular resolution enables the exploration of spatially varying photon yields and vibronic properties at the single-molecule level. By placing individual polycyclic aromatic hydrocarbon molecules into the plasmon cavity formed by the tip of a scanning tunneling microscope and a NaCl-covered Ag(111) surface, molecular light emission spectra are obtained that unravel vibrational progression. In addition, light spectra unveil a signature of the molecule even when the tunneling current is injected well separated from the molecular emitter. This signature exhibits a distance-dependent Fano profile that reflects the subtle interplay between inelastic tunneling electrons, the molecular exciton and localized plasmons in at-distance as well as on-molecule fluorescence. The presented findings open the path to luminescence of a different class of molecules than investigated before and contribute to the understanding of single-molecule luminescence at surfaces in a unified picture.

Observation of three-dimensional internal structure of steel materials by means of serial sectioning with ultrasonic elliptical vibration cutting.

PubMed

Fujisaki, K; Yokota, H; Nakatsuchi, H; Yamagata, Y; Nishikawa, T; Udagawa, T; Makinouchi, A

2010-01-01

A three-dimensional (3D) internal structure observation system based on serial sectioning was developed from an ultrasonic elliptical vibration cutting device and an optical microscope combined with a high-precision positioning device. For bearing steel samples, the cutting device created mirrored surfaces suitable for optical metallography, even for long-cutting distances during serial sectioning of these ferrous materials. Serial sectioning progressed automatically by means of numerical control. The system was used to observe inclusions in steel materials on a scale of several tens of micrometers. Three specimens containing inclusions were prepared from bearing steels. These inclusions could be detected as two-dimensional (2D) sectional images with resolution better than 1 mum. A three-dimensional (3D) model of each inclusion was reconstructed from the 2D serial images. The microscopic 3D models had sharp edges and complicated surfaces.

ECUT: Energy Conversion and Utilization Technologies program. Heterogeneous catalysis modeling program concept

NASA Technical Reports Server (NTRS)

Voecks, G. E.

1983-01-01

Insufficient theoretical definition of heterogeneous catalysts is the major difficulty confronting industrial suppliers who seek catalyst systems which are more active, selective, and stable than those currently available. In contrast, progress was made in tailoring homogeneous catalysts to specific reactions because more is known about the reaction intermediates promoted and/or stabilized by these catalysts during the course of reaction. However, modeling heterogeneous catalysts on a microscopic scale requires compiling and verifying complex information on reaction intermediates and pathways. This can be achieved by adapting homogeneous catalyzed reaction intermediate species, applying theoretical quantum chemistry and computer technology, and developing a better understanding of heterogeneous catalyst system environments. Research in microscopic reaction modeling is now at a stage where computer modeling, supported by physical experimental verification, could provide information about the dynamics of the reactions that will lead to designing supported catalysts with improved selectivity and stability.

Current Approach to the Evaluation and Management of Microscopic Colitis.

PubMed

Cotter, Thomas G; Pardi, Darrell S

2017-02-01

Microscopic colitis is a common cause of chronic watery diarrhea, particularly in the elderly. The accompanying symptoms, which include abdominal pain and fatigue, can markedly impair patients' quality of life. Diagnosis is based upon characteristic histologic findings of the colonic mucosa. This review focuses on the current approach to evaluation and management of patients with microscopic colitis. Although the incidence of microscopic colitis has been increasing over time, recent epidemiological studies show stabilization at 21.0-24.7 cases per 100,000 person-years. Recent research has further expanded our knowledge of the underlying pathophysiology and emphasized the entity of drug-induced microscopic colitis and the association with celiac disease. Two recent randomized studies have confirmed the effectiveness of oral budesonide for both induction and maintenance treatment of microscopic colitis and is now endorsed by the American Gastroenterological Association as first-line treatment. The incidence of microscopic colitis has stabilized at just over 20 cases per 100,000 person-years. Celiac disease and drug-induced microscopic colitis should be considered in all patients diagnosed with microscopic colitis. There are a number of treatments available for patients with microscopic colitis; however, budesonide is the only option well studied in controlled trials and is effective for both induction and maintenance treatment.

Physics Division annual review, 1 April 1980-31 March 1981

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1982-06-01

Progress in nuclear physics research is reported in the following areas: medium-energy physics (pion reaction mechanisms, high-resolution studies and nuclear structure, and two-nucleon physics with pions and electrons); heavy-ion research at the tandem and superconducting linear accelerator (resonant structure in heavy-ion reactions, fusion cross sections, high angular momentum states in nuclei, and reaction mechanisms and distributions of reaction strengths); charged-particle research; neutron and photonuclear physics; theoretical physics (heavy-ion direct-reaction theory, nuclear shell theory and nuclear structure, nuclear matter and nuclear forces, intermediate-energy physics, microscopic calculations of high-energy collisions of heavy ions, and light ion direct reactions); the superconducting linac; acceleratormore » operations; and GeV electron linac. Progress in atomic and molecular physics research is reported in the following areas: dissociation and other interactions of energetic molecular ions in solid and gaseous targets, beam-foil research and collision dynamics of heavy ions, photoionization- photoelectron research, high-resolution laser rf spectroscopy with atomic and molecular beams, moessbauer effect research, and theoretical atomic physics. Studies on interactions of energetic particles with solids are also described. Publications are listed. (WHK)« less

ICAM-1-Targeted Liposomes Loaded with Liver X Receptor Agonists Suppress PDGF-Induced Proliferation of Vascular Smooth Muscle Cells

NASA Astrophysics Data System (ADS)

Huang, Xu; Xu, Meng-Qi; Zhang, Wei; Ma, Sai; Guo, Weisheng; Wang, Yabin; Zhang, Yan; Gou, Tiantian; Chen, Yundai; Liang, Xing-Jie; Cao, Feng

2017-05-01

The proliferation of vascular smooth muscle cells (VSMCs) is one of the key events during the progress of atherosclerosis. The activated liver X receptor (LXR) signalling pathway is demonstrated to inhibit platelet-derived growth factor BB (PDGF-BB)-induced VSMC proliferation. Notably, following PDGF-BB stimulation, the expression of intercellular adhesion molecule-1 (ICAM-1) by VSMCs increases significantly. In this study, anti-ICAM-1 antibody-conjugated liposomes were fabricated for targeted delivery of a water-insoluble LXR agonist (T0901317) to inhibit VSMC proliferation. The liposomes were prepared by filming-rehydration method with uniform size distribution and considerable drug entrapment efficiency. The targeting effect of the anti-ICAM-T0901317 liposomes was evaluated by confocal laser scanning microscope (CLSM) and flow cytometry. Anti-ICAM-T0901317 liposomes showed significantly higher inhibition effect of VSMC proliferation than free T0901317 by CCk8 proliferation assays and BrdU staining. Western blot assay further confirmed that anti-ICAM-T0901317 liposomes inhibited retinoblastoma (Rb) phosphorylation and MCM6 expression. In conclusion, this study identified anti-ICAM-T0901317 liposomes as a promising nanotherapeutic approach to overcome VSMC proliferation during atherosclerosis progression.

A Comparative Study of Microscopic Images Captured by a Box Type Digital Camera Versus a Standard Microscopic Photography Camera Unit

PubMed Central

Desai, Nandini J.; Gupta, B. D.; Patel, Pratik Narendrabhai

2014-01-01

Introduction: Obtaining images of slides viewed by a microscope can be invaluable for both diagnosis and teaching.They can be transferred among technologically-advanced hospitals for further consultation and evaluation. But a standard microscopic photography camera unit (MPCU)(MIPS-Microscopic Image projection System) is costly and not available in resource poor settings. The aim of our endeavour was to find a comparable and cheaper alternative method for photomicrography. Materials and Methods: We used a NIKON Coolpix S6150 camera (box type digital camera) with Olympus CH20i microscope and a fluorescent microscope for the purpose of this study. Results: We got comparable results for capturing images of light microscopy, but the results were not as satisfactory for fluorescent microscopy. Conclusion: A box type digital camera is a comparable, less expensive and convenient alternative to microscopic photography camera unit. PMID:25478350

Recent developments in metabolic bone diseases: a gnathic perspective.

PubMed

Raubenheimer, Erich J; Noffke, Claudia E; Hendrik, Hilde D

2014-12-01

Metabolic bone diseases often are asymptomatic and progress sub clinically. Many patients present at a late stage with catastrophic skeletal and extra skeletal complications. In this article, we provide an overview of normal bone remodeling and a synopsis of recent developments in the following conditions: osteoporosis, rickets/osteomalacia, endocrine-induced bone disease, chronic kidney disease-mineral bone disorder and Paget's disease of bone. Our discussion will emphasize the clinical and microscopic manifestations of these diseases in the jaws.

Primary intraosseous squamous cell carcinoma of the mandible arising de novo.

PubMed

Shamim, Thorakkal

2009-07-01

Primary intraosseous squamous cell carcinoma is an odontogenic tumour with aggressive behaviour usually noticed in 6th to 7th decades of life. The tumour is characterized by progressive swelling of the jaw, pain and loosening of teeth. Microscopically, the lesion is showing foci of keratinising cells separated by collagenous connective tissue stroma. A case of primary intraosseous squamous cell carcinoma of mandible arising de novo in a 40-year-old man is reported.

[Morphology, biology and life-cycle of Plasmodium parasites].

PubMed

Hommel, Marcel

2007-10-01

Laveran first discovered that an infectious agent was responsible for malaria by using a simple microscope, without the assistance of specific stains. Our knowledge of the Plasmodium life cycle and cellular biology has progressed with each technological advance, from Romanovsky staining and histology to electron microscopy, immunocytochemistry, molecular methods and modern imaging techniques. The use of bird, primate and rodent models also made a major contribution, notably in the development of antimalarial drugs that are still in use today.

Targeted DNA Sequencing Reveals Patterns of Local Progression in the Pancreatic Remnant Following Resection of Intraductal Papillary Mucinous Neoplasm (IPMN) of the Pancreas

PubMed Central

Pea, Antonio; Yu, Jun; Rezaee, Neda; Luchini, Claudio; He, Jin; Molin, Marco Dal; Griffin, James F.; Fedor, Helen; Fesharakizadeh, Shahriar; Salvia, Roberto; Weiss, Matthew J.; Bassi, Claudio; Cameron, John L.; Zheng, Lei; Scarpa, Aldo; Hruban, Ralph H.; Lennon, Anne Marie; Goggins, Michael

2016-01-01

Objective The aim of this study was to characterize patterns of local progression following resection for pancreatic intraductal papillary mucinous neoplasms (IPMN) using targeted next-generation sequencing (NGS). Background Progression of neoplastic disease in the remnant pancreas following resection of IPMN may include development of a new IPMN or ductal adenocarcinoma (PDAC). However, it is not clear whether this progression represents recurrence of the same neoplasm or an independent second neoplasm. Methods Targeted-NGS on genes commonly mutated in IPMN and PDAC was performed on tumors from (1) 13 patients who developed disease progression in the remnant pancreas following resection of IPMN; and (2) 10 patients who underwent a resection for PDAC and had a concomitant IPMN. Mutations in the tumors were compared in order to determine the relationship between neoplasms. In parallel, clinical and pathological characteristics of 260 patients who underwent resection of noninvasive IPMN were reviewed to identify risk factors associated with local progression. Results We identified 3 mechanisms underlying local progression in the remnant pancreas: (1) residual microscopic disease at the resection margin, (2) intraparenchymal spread of neoplastic cells, leading to an anatomically separate but genetically related recurrence, and (3) multifocal disease with genetically distinct lesions. Analysis of the 260 patients with noninvasive IPMNs showed that family history of pancreatic cancer (P = 0.027) and high-grade dysplasia (HGD) (P = 0.003) were independent risk factors for the development of an IPMN with HGD or an invasive carcinoma in the remnant pancreas. Conclusions Using NGS, we identify distinct mechanisms for development of metachronous or synchronous neoplasms in patients with IPMN. Patients with a primary IPMN with HGD or with positive family history are at an increased risk to develop subsequent high-risk neoplasms in the remnant pancreas. PMID:27433916

Single molecule microscopy in 3D cell cultures and tissues.

PubMed

Lauer, Florian M; Kaemmerer, Elke; Meckel, Tobias

2014-12-15

From the onset of the first microscopic visualization of single fluorescent molecules in living cells at the beginning of this century, to the present, almost routine application of single molecule microscopy, the method has well-proven its ability to contribute unmatched detailed insight into the heterogeneous and dynamic molecular world life is composed of. Except for investigations on bacteria and yeast, almost the entire story of success is based on studies on adherent mammalian 2D cell cultures. However, despite this continuous progress, the technique was not able to keep pace with the move of the cell biology community to adapt 3D cell culture models for basic research, regenerative medicine, or drug development and screening. In this review, we will summarize the progress, which only recently allowed for the application of single molecule microscopy to 3D cell systems and give an overview of the technical advances that led to it. While initially posing a challenge, we finally conclude that relevant 3D cell models will become an integral part of the on-going success of single molecule microscopy. Copyright © 2014 Elsevier B.V. All rights reserved.

Solitonic Excitations in Fermionic Superfluids and Progress towards Fermi Gas in Uniform Potential

NASA Astrophysics Data System (ADS)

Ku, Mark; Mukherjee, Biswaroop; Guardado-Sanchez, Elmer; Yan, Zhenjie; Patel, Parth; Yefsah, Tarik; Struck, Julian; Zwierlein, Martin

2015-05-01

We follow the evolution of a superfluid Fermi gas of 6Li atoms following a one-sided π phase imprint. Via tomographic imaging, we observe the formation of a planar dark soliton, and its subsequent snaking and decay into a vortex ring. The latter eventually breaks at the boundary of the superfluid, finally leaving behind a single, remnant solitonic vortex. The nodal surface is directly imaged and reveals its decay into a vortex ring via a puncture of the initial soliton plane. At intermediate stages we find evidence for more exotic structures resembling Φ-solitons. The observed evolution of the nodal surface represents dynamics that occurs at the length scale of the interparticle spacing, thus providing new experimental input for microscopic theories of strongly correlated fermions. We also report on the trapping of fermionic atoms of 6Li in a quasi-homogenous all-optical potential, and discuss progress towards directly observing the momentum distribution of the fermions in a box. This new tool offers the possibility to quantitatively study Fermi gases at finite temperature and in the presence of spin-imbalance, with unprecedented accuracy.

[Morphometrical analyze of the middle cerebral artery system at the 13-15 weeks fetuses].

PubMed

Macovei, Georgeta Nataşa; Varlam, H; St Antohe, D

2002-01-01

Tele-encephalization process is accompanied by the appearance and progressive complication of the middle cerebral artery system. The aim of our study is to analyze the morphometrical parameters of the middle cerebral artery branches in the beginning of the edification of its system. We used 162 cerebral hemispheres from 88 fetuses aged of 13-15 weeks. Middle cerebral artery system was injected with a gelatin-China ink mixture and images recorded by means of a Zeiss surgical microscope. Parameters evaluation (length, proximal and distal diameters, external surface, volume, angles of bifurcation) was realized with KS-300 program. At this early age middle cerebral artery system has only 4-5 generations of branches usually resulting from acute angle bifurcations.

Comparison of surgical outcomes after anterior cervical discectomy and fusion: does the intra-operative use of a microscope improve surgical outcomes.

PubMed

Adogwa, Owoicho; Elsamadicy, Aladine; Reiser, Elizabeth; Ziegler, Cole; Freischlag, Kyle; Cheng, Joseph; Bagley, Carlos A

2016-03-01

The primary aim of this study was to assess and compare the complications profile as well as long-term clinical outcomes between patients undergoing an Anterior Cervical Discectomy and Fusion (ACDF) procedure with and without the use of an intra-operative microscope. One hundred and forty adult patients (non-microscope cohort: 81; microscope cohort: 59) undergoing ACDF at a major academic medical center were included in this study. Enrollment criteria included available demographic, surgical and clinical outcome data. All patients had prospectively collected patient-reported outcomes measures and a minimum 2-year follow-up. Patients completed the neck disability index (NDI), short-form 12 (SF-12) and visual analog pain scale (VAS) before surgery, then at 3, 6, 12, and 24 months after surgery. Clinical outcomes and complication rates were compared between both patient cohorts. Baseline characteristics were similar between both cohorts. The mean ± standard deviation duration of surgery was longer in the microscope cohort (microscope: 169±34 minutes vs. non-microscope: 98±42 minutes, P<0.001). There was no significant difference between cohorts in the incidence of nerve root injury (P=0.99) or incidental durotomy (P=0.32). At 3 months post-operatively, both cohorts demonstrated similar improvement in VAS-neck pain (P=0.69), NDI (P=0.86), SF-12 PCS (P=0.84) and SF-12 MCS (P=0.75). At 2-year post-operatively, both the microscope and non-microscope cohorts demonstrated similar improvement from base line in NDI (microscope: 13.52±25.77 vs. non-microscope: 19.51±27.47, P<0.18), SF-12 PCS (microscope: 4.15±26.39 vs. non-microscope: 11.98±22.96, P<0.07), SF-12 MCS (microscope: 9.47±32.38 vs. non-microscope: 16.19±30.44, P<0.21). Interestingly at 2 years, the change in VAS neck pain score was significantly different between cohorts (microscope: 2.22±4.00 vs. non-microscope: 3.69±3.61, P<0.02). Our study demonstrates that the intra-operative use of a microscope does not improve overall surgery-related outcomes, nor does it lead to superior long-term outcomes in pain and functional disability, 2 years after index surgery.

Comparison of surgical outcomes after anterior cervical discectomy and fusion: does the intra-operative use of a microscope improve surgical outcomes

PubMed Central

Elsamadicy, Aladine; Reiser, Elizabeth; Ziegler, Cole; Freischlag, Kyle; Cheng, Joseph; Bagley, Carlos A.

2016-01-01

Background The primary aim of this study was to assess and compare the complications profile as well as long-term clinical outcomes between patients undergoing an Anterior Cervical Discectomy and Fusion (ACDF) procedure with and without the use of an intra-operative microscope. Methods One hundred and forty adult patients (non-microscope cohort: 81; microscope cohort: 59) undergoing ACDF at a major academic medical center were included in this study. Enrollment criteria included available demographic, surgical and clinical outcome data. All patients had prospectively collected patient-reported outcomes measures and a minimum 2-year follow-up. Patients completed the neck disability index (NDI), short-form 12 (SF-12) and visual analog pain scale (VAS) before surgery, then at 3, 6, 12, and 24 months after surgery. Clinical outcomes and complication rates were compared between both patient cohorts. Results Baseline characteristics were similar between both cohorts. The mean ± standard deviation duration of surgery was longer in the microscope cohort (microscope: 169±34 minutes vs. non-microscope: 98±42 minutes, P<0.001). There was no significant difference between cohorts in the incidence of nerve root injury (P=0.99) or incidental durotomy (P=0.32). At 3 months post-operatively, both cohorts demonstrated similar improvement in VAS-neck pain (P=0.69), NDI (P=0.86), SF-12 PCS (P=0.84) and SF-12 MCS (P=0.75). At 2-year post-operatively, both the microscope and non-microscope cohorts demonstrated similar improvement from base line in NDI (microscope: 13.52±25.77 vs. non-microscope: 19.51±27.47, P<0.18), SF-12 PCS (microscope: 4.15±26.39 vs. non-microscope: 11.98±22.96, P<0.07), SF-12 MCS (microscope: 9.47±32.38 vs. non-microscope: 16.19±30.44, P<0.21). Interestingly at 2 years, the change in VAS neck pain score was significantly different between cohorts (microscope: 2.22±4.00 vs. non-microscope: 3.69±3.61, P<0.02). Conclusions Our study demonstrates that the intra-operative use of a microscope does not improve overall surgery-related outcomes, nor does it lead to superior long-term outcomes in pain and functional disability, 2 years after index surgery. PMID:27683692

A preliminary study on using autologous and heterologous boar sperm supernatant from freezing processes as post-thawing solution: its effect on sperm motility.

PubMed

Kaeoket, Kampon; Chanapiwat, Panida; Tummaruk, Padet; Techakumphu, Mongkol; Kunavongkrit, Annop

2011-06-01

The aim of this study was to evaluate the effect of post-thawing dilution with autologous and heterologous sperm supernatant on motility of frozen-thawed boar spermatozoa. During the cryopreservation, sperm supernatant (a combination of seminal plasma and semen extender, 50% v/v) or seminal plasma from nine boars (Duroc, Large White, and Landrace; three in each) was collected by centrifugation and stored frozen until use as post-thawing solution. Sperm pellets were further processed and cryopreserved using control-rate freezer and was thawed at 50°C for 12 s. After thawing, frozen thawed semen samples were diluted with seminal plasma (group A), supernatant from Landrace (group B), supernatant from Large White (group C), supernatant from Duroc (group D), and Modena™ semen extender (group E). Post-thawing motility was evaluated using a phase-contrast microscope after thawing at 1, 10, 20, and 30 min. The present results show that at 1 min, a significantly higher percentage (P ≤ 0.001) of progressive motility was found in groups B (53.3%) and C (53.9%) than the other groups. At 10 min, the highest (P ≤ 0.001) progressive motility was found in groups B (65%) and C (61%). At 20 and 30 min, a significantly higher percentage (P ≤ 0.001) of progressive motility was found in groups B (58.9%), C (53.5%), and D (45.6%) than groups A (3.9%) and E (20.6%). It can be stated that supernatant from the freezing processes (consisting of seminal plasma and Modena™, 50% v/v) had a beneficial effect on post-thawing progressive motility of frozen boar semen.

Comparative study of image contrast in scanning electron microscope and helium ion microscope.

PubMed

O'Connell, R; Chen, Y; Zhang, H; Zhou, Y; Fox, D; Maguire, P; Wang, J J; Rodenburg, C

2017-12-01

Images of Ga + -implanted amorphous silicon layers in a 110 n-type silicon substrate have been collected by a range of detectors in a scanning electron microscope and a helium ion microscope. The effects of the implantation dose and imaging parameters (beam energy, dwell time, etc.) on the image contrast were investigated. We demonstrate a similar relationship for both the helium ion microscope Everhart-Thornley and scanning electron microscope Inlens detectors between the contrast of the images and the Ga + density and imaging parameters. These results also show that dynamic charging effects have a significant impact on the quantification of the helium ion microscope and scanning electron microscope contrast. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

Assessment of nerve ultrastructure by fibre-optic confocal microscopy.

PubMed

Cushway, T R; Lanzetta, M; Cox, G; Trickett, R; Owen, E R

1996-01-01

Fibre-optic technology combined with confocality produces a microscope capable of optical thin sectioning. In this original study, tibial nerves have been stained in a rat model with a vital dye, 4-(4-diethylaminostyryl)-N-methylpyridinium iodide, and analysed by fibre-optic confocal microscopy to produce detailed images of nerve ultrastructure. Schwann cells, nodes of Ranvier and longitudinal myelinated sheaths enclosing axons were clearly visible. Single axons appeared as brightly staining longitudinal structures. This allowed easy tracing of multiple signal axons within the nerve tissue. An accurate measurement of internodal lengths was easily accomplished. This technique is comparable to current histological techniques, but does not require biopsy, thin sectioning or tissue fixing. This study offers a standard for further in vivo microscopy, including the possibility of monitoring the progression of nerve regeneration following microsurgical neurorraphy.

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

Progress is reported on fundamental research in: crystal physics, reactions at metal surfaces, spectroscopy of ionic media, structure of metals, theory of alloying, physical properties, sintering, deformation of crystalline solids, x ray diffraction, metallurgy of superconducting materials, and electron microscope studies. Long-randge applied research studies were conducted for: zirconium metallurgy, materials compatibility, solid reactions, fuel element development, mechanical properties, non-destructive testing, and high-temperature materials. Reactor development support work was carried out for: gas-cooled reactor program, molten-salt reactor, high-flux isotope reactor, space-power program, thorium-utilization program, advanced-test reactor, Army Package Power Reactor, Enrico Fermi fast-breeder reactor, and water desalination program. Other programmore » activities, for which research was conducted, included: thermonuclear project, transuraniunn program, and post-irradiation examination laboratory. Separate abstracts were prepared for 30 sections of the report. (B.O.G.)« less

Solid spherical glass particle impingement studies of plastic materials

NASA Technical Reports Server (NTRS)

Rao, P. V.; Young, S. G.; Buckley, D. H.

1983-01-01

Erosion experiments on polymethyl methacrylate (PMMA), polycarbonate, and polytetrafluoroethylene (PTFE) were conducted with spherical glass beads impacting at normal incidence. Optical and scanning electron microscopic studies and surface profile measurements were made on specimens at predetermined test intervals. During the initial stage of damage to PMMA and polycarbonate, material expands or builds up above the original surface. However, this buildup disappears as testing progresses. Little or no buildup was observed on PTFE. PTFE is observed to be the most resistant material to erosion and PMMA the least. At low impact pressures, material removal mechanisms are believed to be similar to those for metallic materials. However, at higher pressures, surface melting is indicated at the center of impact. Deformation and fatigue appear to play major roles in the material removal process with possible melting or softening.

Treatment of Vascular Soft Tissue Sarcomas With Razoxane, Vindesine, and Radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rhomberg, Walter; Wink, Anna; Pokrajac, Boris

2009-05-01

Purpose: In previous studies, razoxane and vindesine together with radiotherapy was proved to be effective in soft tissue sarcomas (STS). Because razoxane leads to a redifferentiation of pathological tumor blood vessels, it was of particular interest to study the influence of this drug combination in vascular soft tissue sarcomas. Methods and Materials: This open multicenter Phase II study was performed by the Austrian Society of Radiooncology. Among 13 evaluable patients (10 angiosarcomas and 3 hemangio-pericytomas), 9 had unresectable measurable disease, 3 showed microscopic residuals, and 1 had a resection with clear margins. They received a basic treatment with razoxane andmore » vindesine supported by radiation therapy. Outcome measures were objective response rates, survival time, and the incidence of distant metastases. Results: In nine patients with measurable vascular soft tissue sarcomas (eight angiosarcomas and one hemangiopericytoma), 6 complete remissions, 2 partial remissions, and 1 minor remission were achieved, corresponding to a major response rate of 89%. A maintenance therapy with razoxane and vindesine of 1 year or longer led to a suppression of distant metastases. The median survival time from the start of the treatment is 23+ months (range, 3-120+) for 12 patients with macroscopic and microscopic residual disease. The progression-free survival at 6 months was 75%. The combined treatment was associated with a low general toxicity, but attention must be given to increased normal tissue reactions. Conclusions: This trimodal treatment leads to excellent response rates, and it suppresses distant metastases when given as maintenance therapy.« less

Sub-Lethal Dose of Shiga Toxin 2 from Enterohemorrhagic Escherichia coli Affects Balance and Cerebellar Cytoarchitecture

PubMed Central

Pinto, Alipio; Cangelosi, Adriana; Geoghegan, Patricia A.; Tironi-Farinati, Carla; Brener, Gabriela J.; Goldstein, Jorge

2016-01-01

Shiga toxin producing Escherichia coli may damage the central nervous system before or concomitantly to manifested hemolytic–uremic syndrome symptoms. The cerebellum is frequently damaged during this syndrome, however, the deleterious effects of Shiga toxin 2 has never been integrally reported by ultrastructural, physiological and behavioral means. The aim of this study was to determine the cerebellar compromise after intravenous administration of a sub-lethal dose of Shiga toxin 2 by measuring the cerebellar blood–brain barrier permeability, behavioral task of cerebellar functionality (inclined plane test), and ultrastructural analysis (transmission electron microscope). Intravenous administration of vehicle (control group), sub-lethal dose of 0.5 and 1 ηg of Stx2 per mouse were tested for behavioral and ultrastructural studies. A set of three independent experiments were performed for each study (n = 6). Blood–brain barrier resulted damaged and consequently its permeability was significantly increased. Lower scores obtained in the inclined plane task denoted poor cerebellar functionality in comparison to their controls. The most significant lower score was obtained after 5 days of 1 ηg of toxin administration. Transmission electron microscope micrographs from the Stx2-treated groups showed neurons with a progressive neurodegenerative condition in a dose dependent manner. As sub-lethal intravenous Shiga toxin 2 altered the blood brain barrier permeability in the cerebellum the toxin penetrated the cerebellar parenchyma and produced cell damaged with significant functional implications in the test balance. PMID:26904009

Microscopic description of fission dynamics: Toward a 3D computation of the time dependent GCM equation

NASA Astrophysics Data System (ADS)

Regnier, D.; Dubray, N.; Schunck, N.; Verrière, M.

2017-09-01

Accurate knowledge of fission fragment yields is an essential ingredient of numerous applications ranging from the formation of elements in the r-process to fuel cycle optimization in nuclear energy. The need for a predictive theory applicable where no data is available, together with the variety of potential applications, is an incentive to develop a fully microscopic approach to fission dynamics. One of the most promising theoretical frameworks is the time dependent generator coordinate method (TDGCM) applied under the Gaussian overlap approximation (GOA). However, the computational cost of this method makes it difficult to perform calculations with more than two collective degree of freedom. Meanwhile, it is well-known from both semi-phenomenological and fully microscopic approaches that at least four or five dimensions may play a role in the dynamics of fission. To overcome this limitation, we develop the code FELIX aiming to solve the TDGCM+GOA equation for an arbitrary number of collective variables. In this talk, we report the recent progress toward this enriched description of fission dynamics. We will briefly present the numerical methods adopted as well as the status of the latest version of FELIX. Finally, we will discuss fragments yields obtained within this approach for the low energy fission of major actinides.

Novel Coatings for Enhancement of Light-Emitting Diodes (LEDs)

DTIC Science & Technology

2006-10-28

quantum efficiency of LEDs. SAIC’s strength is this area is a proprietary nonimaging optics code. In consultation with Lumileds, SAIC developed designs for...five different optical ele- ments that collect and project light from a LED. The simulations showed that the designs achieve a significant improvement... optical microscope at 100x power the coating is not visible. Fire sample 6DecO4P1 in tube furnace As a first test, sample 6Dec04P1 was progressively

Utilization of nuclear structural proteins for targeted therapy and detection of proliferative and differentiation disorders

DOEpatents

Lelievre, Sophie; Bissell, Mina

2001-01-01

The localization of nuclear apparatus proteins (NUMA) is used to identify tumor cells and different stages in the tumor progression and differentiation processes. There is a characteristic organization of NuMA in tumor cells and in phenotypically normal cells. NuMA distribution patterns are significantly less diffuse in proliferating non-malignant cells compared to malignant cells. The technique encompasses cell immunostaining using a NuMA specific antibody, and microscopic analysis of NuMA distribution within each nucleus.

Central amaurosis induced by an intraocular, posttraumatic fibrosarcoma in a cat.

PubMed

Barrett, P M; Merideth, R E; Alarcon, F L

1995-01-01

A 12-year-old, castrated male, domestic shorthair cat with a previous penetrating trauma to the left globe which progressed to a phthisical eye presented for acute blindness. Ophthalmic examination and electroretinography of the right eye were found to be normal. Following euthanasia, gross and microscopic examinations were completed. A left intraocular, posttraumatic fibrosarcoma with extension to the optic nerve and chiasm and induced right optic nerve fiber degeneration at the optic chiasm with necrosis leading to central amaurosis were diagnosed.

A baiting system for the oral rabies vaccination of wild foxes and skunks.

PubMed

Johnston, D H; Voigt, D R

1982-01-01

A bait delivery system has been developed for red foxes and skunks in Ontario, Canada. A biomarker (Tetracycline HCl) is incorporated into a meatball in a plastic bag. Deposits of tetracycline in teeth are detected microscopically with ultra-violet illumination of undecalcified sections. Baits were dropped from aircraft at the rate of 35 per km2 and accepted by 70% of foxes and 60% of skunks in the test area. Trials of various strains of inactivated vaccines are in progress.

Aplanatic and quasi-aplanatic diffraction gratings

DOEpatents

Hettrick, M.C.

1987-09-14

A reflection diffraction grating having a series of transverse minute grooves of progressively varying spacing along a concave surface enables use of such gratings for x-ray or longer wavelength imaging of objects. The variable groove spacing establishes aplanatism or substantially uniform magnetification across the optical aperture. The grating may be sued, for example, in x-ray microscopes or telescopes of the imaging type and in x-ray microprobed. Increased spatial resolution and field of view may be realized in x-ray imaging. 5 figs.

Pupil engineering for a confocal reflectance line-scanning microscope

NASA Astrophysics Data System (ADS)

Patel, Yogesh G.; Rajadhyaksha, Milind; DiMarzio, Charles A.

2011-03-01

Confocal reflectance microscopy may enable screening and diagnosis of skin cancers noninvasively and in real-time, as an adjunct to biopsy and pathology. Current confocal point-scanning systems are large, complex, and expensive. A confocal line-scanning microscope, utilizing a of linear array detector can be simpler, smaller, less expensive, and may accelerate the translation of confocal microscopy in clinical and surgical dermatology. A line scanner may be implemented with a divided-pupil, half used for transmission and half for detection, or with a full-pupil using a beamsplitter. The premise is that a confocal line-scanner with either a divided-pupil or a full-pupil will provide high resolution and optical sectioning that would be competitive to that of the standard confocal point-scanner. We have developed a confocal line-scanner that combines both divided-pupil and full-pupil configurations. This combined-pupil prototype is being evaluated to determine the advantages and limitations of each configuration for imaging skin, and comparison of performance to that of commercially available standard confocal point-scanning microscopes. With the combined configuration, experimental evaluation of line spread functions (LSFs), contrast, signal-to-noise ratio, and imaging performance is in progress under identical optical and skin conditions. Experimental comparisons between divided-pupil and full-pupil LSFs will be used to determine imaging performance. Both results will be compared to theoretical calculations using our previously reported Fourier analysis model and to the confocal point spread function (PSF). These results may lead to a simpler class of confocal reflectance scanning microscopes for clinical and surgical dermatology.

Microscope use in clinical veterinary practice and potential implications for veterinary school curricula.

PubMed

Stewart, Sherry M; Dowers, Kristy L; Cerda, Jacey R; Schoenfeld-Tacher, Regina M; Kogan, Lori R

2014-01-01

Microscopy (skill of using a microscope) and the concepts of cytology (study of cells) and histology (study of tissues) are most often taught in professional veterinary medicine programs through the traditional method of glass slides and light microscopes. Several limiting factors in veterinary training programs are encouraging educators to explore innovative options for teaching microscopy skills and the concepts of cytology and histology. An anonymous online survey was administered through the Colorado Veterinary Medical Association to Colorado veterinarians working in private practice. It was designed to assess their current usage of microscopes for cytological and histological evaluation of specimens and their perceptions of microscope use in their veterinary education. The first part of the survey was answered by 183 veterinarians, with 104 indicating they had an onsite diagnostic lab. Analysis pertaining to the use of the microscope in practice and in veterinary programs was conducted on this subset. Most respondents felt the amount of time spent in the curriculum using a microscope was just right for basic microscope use and using the microscope for viewing and learning about normal and abnormal histological sections and clinical cytology. Participants felt more emphasis could be placed on clinical and diagnostic cytology. Study results suggest that practicing veterinarians frequently use microscopes for a wide variety of cytological diagnostics. However, only two respondents indicated they prepared samples for histological evaluation. Veterinary schools should consider these results against the backdrop of pressure to implement innovative teaching techniques to meet the changing needs of the profession.

Acute glomerulonephritis: a 7 years follow up of children in center of Iran.

PubMed

Sepahi, Mohsen Akhavan; Shajari, Ahmad; Shakiba, Mehrdad; Shooshtary, Fatemeh Khalife; Salimi, Mohammad Hossein

2011-01-01

Acute glomerulonephritis (AGN) is a type of renal disease which indicates the inflammation of glomerulus and nephrons. This study was carried on 94 children, <15 years old with the diagnosis of AGN who were admitted to Qom and Yazd's hospitals between 2000 and 2006. Data were collected using hospital records on admission, progression notes and outpatient follow up. Among 94 patients, 55.3% were male and 44.6% were female. Mean age of patients was 8.2±2.7 years old. Acute post streptococcal glomerulonephritis (APSGN) was reported in 92.5%, membranoproliferative glomerulonephritis in 4.2%, hemolytic uremic syndrome in 2.1% and IgA nephropathy in 1.06%. There was no significant differences between GN types and gender (P=0.54). Clinical manifestation included edema in 68.8%, oliguria in 36.3%, gross hematuria in 69.1%, HTN in 61.7% and anuria in 1.06%. Microscopic hematuria was detected in all patients. In the time of follow up none of patients had hypertension, 3.1% had proteinuria and 6.3% had microscopic hematuria. APSGN is the most common causes of AGN in Qom and Yazd's children. Early diagnosis and treatment of APSGN may protect children from long term morbidity and mortality and improve quality of life.

Bidimensional and Doppler ultrasonographic evaluation of postpartum uterine involution in the queen.

PubMed

Blanco, P G; Rodríguez, R; Batista, P R; Barrena, J P; Arias, D O; Gobello, C

2015-07-01

The aim of this study was to describe bidimensional and Doppler ultrasonographic changes of uterine involution during normal feline puerperium. Secondary, the postpartum vaginal discharge was described. Twelve pregnant female cats were included in this study. After queening, vulvar discharge was grossly and microscopically examined daily. Bidimensional and Doppler ultrasonographic examinations of the uterus were performed on Days -4 to -2, 4, 11, 18, and 25 from parturition. Total uterine diameter, uterine wall thickness, uterine lumen contents, peak systolic velocity, end diastolic velocity, and resistance index of uterine arteries were measured. The cats presented serosanguineous vulvar discharge for a mean of 3 ± 1 days after parturition, and the cytology revealed 70% to 80% of erythrocytes, which progressively decreased up to Day 13. Immediately after parturition, there were less than 20% neutrophils, and this percentage gradually diminished to 0% to 1% at the end of the study. Uterine total diameter diminished up to Day 25 (P < 0.01), when ultrasonographic uterine dimensions were similar to that of anestrus. A progressive decrease of uterine wall thickness (P < 0.05), uterine lumen contents (P < 0.01), peak systolic velocity (P < 0.01), and end diastolic velocity (P < 0.01) was found throughout the study period. Conversely, resistance index increased during the first week after parturition (P < 0.01). It is concluded that the uterine artery blood flow progressively decreased during the first 25 days after parturition, which was associated with the bidimensional ultrasonographic regression of the organ. Although lochial discharge disappeared far before ultrasonographic involution, cytologic findings further corroborated the duration of this regression process. Copyright © 2015 Elsevier Inc. All rights reserved.

Fossil diatoms and neogene paleolimnology

USGS Publications Warehouse

Platt, Bradbury J.

1988-01-01

Diatoms have played an important role in the development of Neogene continental biostratigraphy and paleolimnology since the mid-19th Century. The history of progress in Quaternary diatom biostratigraphy has developed as a result of improved coring techniques that enable sampling sediments beneath existing lakes coupled with improved chronological control (including radiometric dating and varve enumeration), improved statistical treatment of fossil diatom assemblages (from qualitative description to influx calculations of diatom numbers or volumes), and improved ecological information about analogous living diatom associations. The last factor, diatom ecology, is the most critical in many ways, but progresses slowly. Fortunately, statistical comparison of modern diatom assemblages and insightful studies of the nutrient requirements of some common freshwater species are enabling diatom paleolimnologists to make more detailed interpretations of the Quaternary record than had been possible earlier, and progress in the field of diatom biology and ecology will continue to refine paleolimnological studies. The greater age and geologic setting of Tertiary diatomaceous deposits has prompted their study in the contexts of geologic history, biochronology and evolution. The distribution of diatoms of marine affinities in continental deposits has given geologists insights about tectonism and sea-level change, and the distribution of distinctive (extinct?) diatoms has found utilization both in making stratigraphic correlations between outcrops of diatomaceous deposits and in various types of biochronological studies that involve dating deposits in different areas. A continental diatom biochronologic scheme will rely upon evolution, such as the appearance of new genera within a family, in combination with regional environmental changes that are responsible for the wide distribution of distinctive diatom species. The increased use of the scanning electron microscope for the detailed descriptions of fossil diatoms will provide the basis for making more accurate correlations and identifications, and the micromorphological detail for speculations about evolutionary relationships. ?? 1988.

Is fluorescein-guided technique able to help in resection of high-grade gliomas?

PubMed

Acerbi, Francesco; Broggi, Morgan; Eoli, Marica; Anghileri, Elena; Cavallo, Claudio; Boffano, Carlo; Cordella, Roberto; Cuppini, Lucia; Pollo, Bianca; Schiariti, Marco; Visintini, Sergio; Orsi, Chiara; La Corte, Emanuele; Broggi, Giovanni; Ferroli, Paolo

2014-02-01

Fluorescein, a dye that is widely used as a fluorescent tracer, accumulates in cerebral areas where the blood-brain barrier is damaged. This quality makes it an ideal dye for the intraoperative visualization of high-grade gliomas (HGGs). The authors report their experience with a new fluorescein-guided technique for the resection of HGGs using a dedicated filter on the surgical microscope. The authors initiated a prospective Phase II trial (FLUOGLIO) in September 2011 with the objective of evaluating the safety of fluorescein-guided surgery for HGGs and obtaining preliminary evidence regarding its efficacy for this purpose. To be eligible for participation in the study, a patient had to have suspected HGG amenable to complete resection of the contrast-enhancing area. The present report is based on the analysis of the short- and long-term results in 20 consecutive patients with HGGs (age range 45-74 years), enrolled in the study since September 2011. In all cases fluorescein (5-10 mg/kg) was injected intravenously after intubation. Tumor resection was performed with microsurgical technique and fluorescence visualization by means of BLUE 400 or YELLOW 560 filters on a Pentero microscope. The median preoperative tumor volume was 30.3 cm(3) (range 2.4-87.8 cm(3)). There were no adverse reactions related to fluorescein administration. Complete removal of contrast-enhanced tumor was achieved in 80% of the patients. The median duration of follow-up was 10 months. The 6-months progression-free survival rate was 71.4% and the median survival was 11 months. Analysis of these 20 cases suggested that fluorescein-guided technique with a dedicated filter on the surgical microscope is safe and allows a high rate of complete resection of contrast-enhanced tumor as determined on early postoperative MRI. Clinical trial registration no.: 2011-002527-18 (EudraCT).

Progressive polyuria without vasopressin neuron loss in a mouse model for familial neurohypophysial diabetes insipidus.

PubMed

Hayashi, Masayuki; Arima, Hiroshi; Ozaki, Noriyuki; Morishita, Yoshiaki; Hiroi, Maiko; Ozaki, Nobuaki; Nagasaki, Hiroshi; Kinoshita, Noriaki; Ueda, Masatsugu; Shiota, Akira; Oiso, Yutaka

2009-05-01

Familial neurohypophysial diabetes insipidus (FNDI), an autosomal dominant disorder, is mostly caused by mutations in the gene of neurophysin II (NPII), the carrier protein of arginine vasopressin (AVP). Previous studies suggest that loss of AVP neurons might be the cause of polyuria in FNDI. Here we analyzed knockin mice expressing mutant NPII that causes FNDI in humans. The heterozygous mice manifested progressive polyuria as do patients with FNDI. Immunohistochemical analyses revealed that inclusion bodies that were not immunostained with antibodies for mutant NPII, normal NPII, or AVP were present in the AVP cells in the supraoptic nucleus (SON), and that the size of inclusion bodies gradually increased in parallel with the increases in urine volume. Electron microscopic analyses showed that aggregates existed in the endoplasmic reticulum (ER) as well as in the nucleus of AVP neurons in 1-mo-old heterozygous mice. At 12 mo, dilated ER filled with aggregates occupied the cytoplasm of AVP cells, while few aggregates were found in the nucleus. Analyses with in situ hybridization revealed that expression of AVP mRNA was significantly decreased in the SON in the heterozygous mice compared with that in wild-type mice. Counting cells expressing AVP mRNA in the SON indicated that polyuria had progressed substantially in the absence of neuronal loss. These data suggest that cell death is not the primary cause of polyuria in FNDI, and that the aggregates accumulated in the ER might be involved in the dysfunction of AVP neurons that lead to the progressive polyuria.

Whey-hydrolyzed peptide-enriched immunomodulating diet prevents progression of liver cirrhosis in rats.

PubMed

Jobara, Kanta; Kaido, Toshimi; Hori, Tomohide; Iwaisako, Keiko; Endo, Kosuke; Uchida, Yoichiro; Uemoto, Shinji

2014-10-01

Liver fibrosis and subsequent cirrhosis is a major cause of death worldwide, but few effective antifibrotic therapies are reported. Whey-hydrolyzed peptide (WHP), a major peptide component of bovine milk, exerts anti-inflammatory effects in experimental models. A WHP-enriched diet is widely used for immunomodulating diets (IMD) in clinical fields. However, the effects of WHP on liver fibrosis remain unknown. The aim of this study was to investigate the antifibrotic effects of WHP in a rat cirrhosis model. Progressive liver fibrosis was induced by repeated intraperitoneal administration of dimethylnitrosamine (DMN) for 3 wk. Rats were fed either a WHP-enriched IMD (WHP group) or a control enteral diet (control group). The degree of liver fibrosis was compared between groups. Hepatocyte-protective effects were examined using hepatocytes isolated from rats fed a WHP diet. Reactive oxygen species and glutathione in liver tissue were investigated in the DMN cirrhosis model. Macroscopic and microscopic progression of liver fibrosis was remarkably suppressed in the WHP group. Elevated serum levels of liver enzymes and hyaluronic acid, and liver tissue hydroxyproline content were significantly attenuated in the WHP group. Necrotic hepatocyte rates with DMN challenge, isolated from rats fed a WHP-enriched IMD, were significantly lower. In the DMN cirrhosis model, reactive oxygen species were significantly lower, and glutathione was significantly higher in the WHP group's whole liver tissue. A WHP-enriched IMD effectively prevented progression of DMN-induced liver fibrosis in rats via a direct hepatocyte-protective effect and an antioxidant effect through glutathione synthesis. Copyright © 2014 Elsevier Inc. All rights reserved.

Cell Size Clues for the Allee Effect in Vegetative Amoeba Suspension Culture

NASA Astrophysics Data System (ADS)

Franck, Carl; Rappazzo, Brendan; Wang, Xiaoning; Segota, Igor

That cells proliferate at higher rates with increasing density helps us appreciate and understand the development of multicellular behavior through the study of dilute cell systems. However, arduous cell counting with a microscope reveals that in the model eukaryote, Dictyostelium discoideum this transition is difficult to ascertain and thereby further explore despite our earlier progress (Phys. Rev. E 77, 041905, (2008)). Here we report preliminary evidence that the slow proliferation phase is well characterized by reduced cell size compared to the wide distribution of cell sizes in the familiar exponential proliferation phase of moderate densities. This observation is enabled by a new system for characterizing cells in stirred suspension cultures. Our technique relies on quickly acquiring magnitude distributions of detected flashes of laser light scattered in situ by cell targets.

Effects of Simulated Weightlessness on Mammalian Development. Part 2: Meiotic Maturation of Mouse Oocytes During Clinostat Rotation

NASA Technical Reports Server (NTRS)

Wolgemuth, D. J.; Grills, G. S.

1985-01-01

In order to understand the role of gravity in basic cellular processes that are important during development, the effects of a simulated microgravity environment on mammalian gametes and early embryos cultured in vitro are examined. A microgravity environment is simulated by use of a clinostat, which essentially reorients cells relative to the gravity vector. Initial studies have focused on assessing the effects of clinostat rotation on the meiotic progression of mouse oocytes. Modifications centered on providing the unique in vitro culture of the clinostat requirements of mammalian oocytes and embryos: 37 C temperature, constant humidity, and a 5% CO2 in air environment. The oocytes are observed under the dissecting microscope for polar body formation and gross morphological appearance. They are then processed for cytogenetic analysis.

Quantitative high-resolution genomic analysis of single cancer cells.

PubMed

Hannemann, Juliane; Meyer-Staeckling, Sönke; Kemming, Dirk; Alpers, Iris; Joosse, Simon A; Pospisil, Heike; Kurtz, Stefan; Görndt, Jennifer; Püschel, Klaus; Riethdorf, Sabine; Pantel, Klaus; Brandt, Burkhard

2011-01-01

During cancer progression, specific genomic aberrations arise that can determine the scope of the disease and can be used as predictive or prognostic markers. The detection of specific gene amplifications or deletions in single blood-borne or disseminated tumour cells that may give rise to the development of metastases is of great clinical interest but technically challenging. In this study, we present a method for quantitative high-resolution genomic analysis of single cells. Cells were isolated under permanent microscopic control followed by high-fidelity whole genome amplification and subsequent analyses by fine tiling array-CGH and qPCR. The assay was applied to single breast cancer cells to analyze the chromosomal region centred by the therapeutical relevant EGFR gene. This method allows precise quantitative analysis of copy number variations in single cell diagnostics.

Early spinal cord and brainstem involvement in infantile Leigh syndrome possibly caused by a novel variant.

PubMed

Tenney, Jeffrey R; Prada, Carlos E; Hopkin, Robert J; Hallinan, Barbara E

2013-12-01

Leigh syndrome, due to a dysfunction of mitochondrial energy metabolism, is a genetically heterogeneous and progressive neurologic disorder that usually occurs in infancy and childhood. Its clinical presentation and neuroimaging findings can be variable, especially early in the course of the disease. This report presents a patient with infantile Leigh syndrome who had atypical radiologic findings on serial neuroimaging studies with early and severe involvement of the cervical spinal cord and brainstem and injury to the thalami and basal ganglia occurring only late in the clinical course. Postmortem microscopic examination supported this timing of injury within the central nervous system. In addition, mitochondrial deoxyribonucleic acid sequencing showed a novel homoplasmic variant that could be responsible for this unique lethal form of Leigh syndrome.

The effect of progressive hearing loss on the morphology of endbulbs of Held and bushy cells.

PubMed

Connelly, Catherine J; Ryugo, David K; Muniak, Michael A

2017-01-01

Studies of congenital and early-onset deafness have demonstrated that an absence of peripheral sound-evoked activity in the auditory nerve causes pathological changes in central auditory structures. The aim of this study was to establish whether progressive acquired hearing loss could lead to similar brain changes that would degrade the precision of signal transmission. We used complementary physiologic hearing tests and microscopic techniques to study the combined effect of both magnitude and duration of hearing loss on one of the first auditory synapses in the brain, the endbulb of Held (EB), along with its bushy cell (BC) target in the anteroventral cochlear nucleus. We compared two hearing mouse strains (CBA/Ca and heterozygous shaker-2 +/- ) against a model of early-onset progressive hearing loss (DBA/2) and a model of congenital deafness (homozygous shaker-2 -/- ), examining each strain at 1, 3, and 6 months of age. Furthermore, we employed a frequency model of the mouse cochlear nucleus to constrain our analyses to regions most likely to exhibit graded changes in hearing function with time. No significant differences in the gross morphology of EB or BC structure were observed in 1-month-old animals, indicating uninterrupted development. However, in animals with hearing loss, both EBs and BCs exhibited a graded reduction in size that paralleled the hearing loss, with the most severe pathology seen in deaf 6-month-old shaker-2 -/- mice. Ultrastructural pathologies associated with hearing loss were less dramatic: minor changes were observed in terminal size but mitochondrial fraction and postsynaptic densities remained relatively stable. These results indicate that acquired progressive hearing loss can have consequences on auditory brain structure, with prolonged loss leading to greater pathologies. Our findings suggest a role for early intervention with assistive devices in order to mitigate long-term pathology and loss of function. Copyright © 2016 Elsevier B.V. All rights reserved.

Urinary Tract Infection (UTI) Caused by Fusarium proliferatum in an Agranulocytosis Patient and a Review of Published Reports.

PubMed

Su, Huilin; Zhang, Qiangqiang; Li, Li; Zhao, Ying; Zhu, Junhao; Zhu, Min

2016-02-01

Infections caused by Fusarium species are increasing in frequency among immunocompromised hosts, but urinary tract infection (UTI) due to Fusarium proliferatum has not been reported in the literature so far. We describe a case of UTI caused by F. proliferatum in a 47-year-old man who was diagnosed with rectal cancer and metastasis. He underwent radical resection of rectal carcinoma and local resection of hepatic metastases. After the first adjuvant chemotherapy, the patient presented the obvious high fever, severely diarrhea and progressive decline of the white blood cell count. The direct microscopic examination of fungi in urine was positive, and the fungal cultures showed white, cotton-like colony. After the DNA sequencing, it was identified as F. proliferatum. We gave the patient itraconazole and other antibiotics to fight the infection. A month later, the temperature dropped to normal and the results of the direct microscopic examination and culture of fungi in urine turn negative. The itraconazole is effective against F. proliferatum.

The Composition and Organization of Cytoplasm in Prebiotic Cells

PubMed Central

Trevors, Jack T.

2011-01-01

This article discusses the hypothesized composition and organization of cytoplasm in prebiotic cells from a theoretical perspective and also based upon what is currently known about bacterial cytoplasm. It is unknown if the first prebiotic, microscopic scale, cytoplasm was initially contained within a primitive, continuous, semipermeable membrane, or was an uncontained gel substance, that later became enclosed by a continuous membrane. Another possibility is that the first cytoplasm in prebiotic cells and a primitive membrane organized at the same time, permitting a rapid transition to the first cell(s) capable of growth and division, thus assisting with the emergence of life on Earth less than a billion years after the formation of the Earth. It is hypothesized that the organization and composition of cytoplasm progressed initially from an unstructured, microscopic hydrogel to a more complex cytoplasm, that may have been in the volume magnitude of about 0.1–0.2 μm3 (possibly less if a nanocell) prior to the first cell division. PMID:21673913

Embryonic hematopoiesis under microscopic observation.

PubMed

Klaus, Anna; Robin, Catherine

2017-08-15

Hematopoietic stem cells (HSCs) are at the origin of adult hematopoiesis, providing an organism with all blood cell types needed throughout life. During embryonic development a first wave of hematopoiesis (independent of HSCs) allows the survival and growth of the embryo until birth. A second wave of hematopoiesis that will last into adulthood depends on the production of HSCs that begins at mid-gestation in large arteries such as the aorta. HSC production occurs through a hemogenic endothelial to hematopoietic transition (EHT) process and the formation of hematopoietic clusters in most vertebrate species. Advances in understanding EHT, cluster formation and HSC production were triggered by combined progresses made in the development of in vivo assays, microscopy, imaging and fluorescence tools. Here, we review the current knowledge on developmental hematopoiesis with a focus on the first step of HSC production in the aorta and how microscopic approaches have contributed to a better understanding of the vital process of blood cell formation. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

An Automated High-throughput Array Microscope for Cancer Cell Mechanics

NASA Astrophysics Data System (ADS)

Cribb, Jeremy A.; Osborne, Lukas D.; Beicker, Kellie; Psioda, Matthew; Chen, Jian; O'Brien, E. Timothy; Taylor, Russell M., II; Vicci, Leandra; Hsiao, Joe Ping-Lin; Shao, Chong; Falvo, Michael; Ibrahim, Joseph G.; Wood, Kris C.; Blobe, Gerard C.; Superfine, Richard

2016-06-01

Changes in cellular mechanical properties correlate with the progression of metastatic cancer along the epithelial-to-mesenchymal transition (EMT). Few high-throughput methodologies exist that measure cell compliance, which can be used to understand the impact of genetic alterations or to screen the efficacy of chemotherapeutic agents. We have developed a novel array high-throughput microscope (AHTM) system that combines the convenience of the standard 96-well plate with the ability to image cultured cells and membrane-bound microbeads in twelve independently-focusing channels simultaneously, visiting all wells in eight steps. We use the AHTM and passive bead rheology techniques to determine the relative compliance of human pancreatic ductal epithelial (HPDE) cells, h-TERT transformed HPDE cells (HPNE), and four gain-of-function constructs related to EMT. The AHTM found HPNE, H-ras, Myr-AKT, and Bcl2 transfected cells more compliant relative to controls, consistent with parallel tests using atomic force microscopy and invasion assays, proving the AHTM capable of screening for changes in mechanical phenotype.

Experimental demonstration of a single-molecule electric motor.

PubMed

Tierney, Heather L; Murphy, Colin J; Jewell, April D; Baber, Ashleigh E; Iski, Erin V; Khodaverdian, Harout Y; McGuire, Allister F; Klebanov, Nikolai; Sykes, E Charles H

2011-09-04

For molecules to be used as components in molecular machines, methods that couple individual molecules to external energy sources and that selectively excite motion in a given direction are required. Significant progress has been made in the construction of molecular motors powered by light and by chemical reactions, but electrically driven motors have not yet been built, despite several theoretical proposals for such motors. Here we report that a butyl methyl sulphide molecule adsorbed on a copper surface can be operated as a single-molecule electric motor. Electrons from a scanning tunnelling microscope are used to drive the directional motion of the molecule in a two-terminal setup. Moreover, the temperature and electron flux can be adjusted to allow each rotational event to be monitored at the molecular scale in real time. The direction and rate of the rotation are related to the chiralities of both the molecule and the tip of the microscope (which serves as the electrode), illustrating the importance of the symmetry of the metal contacts in atomic-scale electrical devices.

G12V Kras mutations in cervical cancer under virtual microscope of molecular dynamics simulations.

PubMed

Chen, X P; Xu, W H; Xu, D F; Fu, S M; Ma, Z C

2016-01-01

Kras mutations and cancers are common and their role in the progression of cancer is well known and elucidated. The present work is searching for the most deleterious mutation of the four found at codon 12 and 13 of Kras in cervical cancers using prediction servers; different servers were used to look into different factors that govern the protein function. The in silico results predicted G12V to be the most devastating; this particular mutation was then subjected to molecular dynamics simulation (MDS) for further analysis. The authors' approach of MDSs helped them to place the native and mutant structure under virtual microscope and observe their dynamics over time. The results generated are enlightening the effect of G12V variation on the dynamics of Kras. The structural variation between the native and mutant Kras over 50 nanoseconds (ns) run varied at every parameter checked and the results are in excellent agreement with the available experimental data.

Towards more accurate and reliable predictions for nuclear applications

NASA Astrophysics Data System (ADS)

Goriely, Stephane; Hilaire, Stephane; Dubray, Noel; Lemaître, Jean-François

2017-09-01

The need for nuclear data far from the valley of stability, for applications such as nuclear astrophysics or future nuclear facilities, challenges the robustness as well as the predictive power of present nuclear models. Most of the nuclear data evaluation and prediction are still performed on the basis of phenomenological nuclear models. For the last decades, important progress has been achieved in fundamental nuclear physics, making it now feasible to use more reliable, but also more complex microscopic or semi-microscopic models in the evaluation and prediction of nuclear data for practical applications. Nowadays mean-field models can be tuned at the same level of accuracy as the phenomenological models, renormalized on experimental data if needed, and therefore can replace the phenomenological inputs in the evaluation of nuclear data. The latest achievements to determine nuclear masses within the non-relativistic HFB approach, including the related uncertainties in the model predictions, are discussed. Similarly, recent efforts to determine fission observables within the mean-field approach are described and compared with more traditional existing models.

Structural Fingerprinting of Nanocrystals in the Transmission Electron Microscope

NASA Astrophysics Data System (ADS)

Rouvimov, Sergei; Plachinda, Pavel; Moeck, Peter

2010-03-01

Three novel strategies for the structurally identification of nanocrystals in a transmission electron microscope are presented. Either a single high-resolution transmission electron microscopy image [1] or a single precession electron diffractogram (PED) [2] may be employed. PEDs from fine-grained crystal powders may also be utilized. Automation of the former two strategies is in progress and shall lead to statistically significant results on ensembles of nanocrystals. Open-access databases such as the Crystallography Open Database which provides more than 81,500 crystal structure data sets [3] or its mainly inorganic and educational subsets [4] may be utilized. [1] http://www.scientificjournals.org/journals 2007/j/of/dissertation.htm [2] P. Moeck and S. Rouvimov, in: {Drugs and the Pharmaceutical Sciences}, Vol. 191, 2009, 270-313 [3] http://cod.ibt.lt, http://www.crystallography.net, http://cod.ensicaen.fr, http://nanocrystallography.org, http://nanocrystallography.net, http://journals.iucr.org/j/issues/2009/04/00/kk5039/kk5039.pdf [4] http://nanocrystallography.research.pdx.edu/CIF-searchable

Microscopy of semiconducting materials

NASA Astrophysics Data System (ADS)

Pennycook, S. J.

1991-04-01

The purpose of the trip was to present an invited talk at the 7th Oxford Conference on Microscopy of Semiconducting Materials entitled, High-Resolution Z-Contrast Imaging of Heterostructures and Superlattices, (Oxford, United Kingdom) and to visit VG Microscopes, East Grinstead, for discussions on the progress of the Oak Ridge National Laboratory (ORNL) 300-kV high-resolution scanning transmission electron microscope (STEM), which is currently on order. The traveler also visited three other institutions with 100-kV STEMs that either have or intend to purchase the necessary modifications to provide Z-contrast capability similar to that of the existing ORNL machine. Specifically, Max-Planck Institut fuer Metallforschung (Stuttgart, Germany); Cambridge University, Department of Materials Science and Metallurgy (Cambridge, United Kingdom); and Cavendish Laboratory, Cambridge University (Cambridge, United Kingdom) were visited. In addition, discussions were held with C. Humphreys on the possibility of obtaining joint funding for collaborative research involving electron beam writing and Z-contrast imaging in the Cambridge and Oak Ridge STEMs, respectively.

Full-field x-ray nano-imaging at SSRF

NASA Astrophysics Data System (ADS)

Deng, Biao; Ren, Yuqi; Wang, Yudan; Du, Guohao; Xie, Honglan; Xiao, Tiqiao

2013-09-01

Full field X-ray nano-imaging focusing on material science is under developing at SSRF. A dedicated full field X-ray nano-imaging beamline based on bending magnet will be built in the SSRF phase-II project. The beamline aims at the 3D imaging of the nano-scale inner structures. The photon energy range is of 5-14keV. The design goals with the field of view (FOV) of 20μm and a spatial resolution of 20nm are proposed at 8 keV, taking a Fresnel zone plate (FZP) with outermost zone width of 25 nm. Futhermore, an X-ray nano-imaging microscope is under developing at the SSRF BL13W beamline, in which a larger FOV will be emphasized. This microscope is based on a beam shaper and a zone plate using both absorption contrast and Zernike phase contrast, with the optimized energy set to 10keV. The detailed design and the progress of the project will be introduced.

Morphology and Morphometry of the Lung in Corn Snakes (Pantherophis guttatus) Infected with Three Different Strains of Ferlavirus.

PubMed

Starck, J M; Neul, A; Schmidt, V; Kolb, T; Franz-Guess, S; Balcecean, D; Pees, M

2017-05-01

Ophidian paramyxovirus (ferlavirus) is a global threat to reptilian sauropsids in herpetological collections, with occasional but fatal effects. This study characterizes the effects of three different genetic strains of ferlavirus on the dynamic changes of histology and morphometry of the lung of corn snakes (Pantherophis guttatus). Lungs from 42 corn snakes were either sham-infected or infected experimentally under standardized conditions. From 4 to 49 days after intratracheal inoculation, the lungs were examined qualitatively and quantitatively. Progressive microscopical changes were seen in the lung. Initially, increased numbers of heterophils were observed in the interstitium followed by proliferation and vacuolation of epithelial cells lining faveoli. Electron microscopy revealed loss of type-I pneumocytes, hyperplasia of type-II pneumocytes, and interstitial infiltrates of heterophils and mononuclear cells. With progression of disease the respiratory epithelium was initially overgrown by transformed type-II pneumocytes and later became multilayered. The results of the study suggest that the respiratory capacity of the lungs declines with disease development. The dynamics of disease development and histopathology differed in snakes infected with different ferlavirus genogroups. Animals infected with virus genogroup B developed histopathological changes and morphometric changes more rapidly and of greater intensity than snakes infected with viruses from genogroups A or C. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Diagnostic Approach for Rodent Progressive Cardiomyopathy and Like Lesions in Toxicology Studies up to 28 Days in the Sprague Dawley Rat (Part 2 of 2).

PubMed

Hailey, James R; Maleeff, Beverly E; Thomas, Heath C; Pearse, Gail; Klapwijk, Jan C; Cristofori, Patrizia G; Berridge, Brian; Kimbrough, Carie L; Parker, George A; Morton, Daniel; Elmore, Susan; Hardisty, Jerry F; Dybdal, Noel O; Rehagen, David A; Fikes, James D; Lamb, Martin; Biddle, Kathleen; Buetow, Bernard S; Carreira, Vinicius; Nyska, Abraham; Tripathi, Niraj K; Workman, Heather C; Bienvenu, Jean-Guy; Brees, Ingrid; Turk, James R; Adler, Rick R

2017-12-01

To test the diagnostic approach described in part 1 of this article, 2 exercises were completed by pathologists from multiple companies/agencies. Pathologist's examination of whole slide image (WSI) heart sections from rats using personal diagnostic approaches (exercise #1) corroborated conclusions from study #1. Using the diagnostic approach described in part 1, these pathologists examined the same WSI heart sections (exercise #2) to determine whether that approach increased consistency of diagnosis of rodent progressive cardiomyopathy (PCM) lesions. In exercise #2, there was improved consistency of categorization of small borderline morphologies and mild lesions, but a decrement in consistency of categorizing minimal lesions. Exercises 1 and 2 suggest the described diagnostic approach is representative of that in use by the majority of toxicologic pathologists across companies/agencies and that application by all may improve diagnostic consistency of PCM/like lesions. Additionally, a criterion of approximately 5% heart section involvement is suggested for separating mild from moderate or greater severity. While evidence is not absolute, until further investigation shows otherwise, microscopic changes resembling PCM, but located in the epicardial and subepicardial region of the right ventricle, may be considered as part of the spectrum of PCM.

Intrinsic and environmental effects on the interference properties of a high-performance quantum dot single-photon source

NASA Astrophysics Data System (ADS)

Gerhardt, Stefan; Iles-Smith, Jake; McCutcheon, Dara P. S.; He, Yu-Ming; Unsleber, Sebastian; Betzold, Simon; Gregersen, Niels; Mørk, Jesper; Höfling, Sven; Schneider, Christian

2018-05-01

We report a joint experimental and theoretical study of the interference properties of a single-photon source based on a In(Ga)As quantum dot embedded in a quasiplanar GaAs microcavity. Using resonant laser excitation with a pulse separation of 2 ns, we find near-perfect interference of the emitted photons, and a corresponding indistinguishability of I =(99.6 -1.4+0.4)% . For larger pulse separations, quasiresonant excitation conditions, increasing pump power, or with increasing temperature, the interference contrast is progressively and notably reduced. We present a systematic study of the relevant dephasing mechanisms and explain our results in the framework of a microscopic model of our system. For strictly resonant excitation, we show that photon indistinguishability is independent of pump power, but strongly influenced by virtual phonon-assisted processes which are not evident in excitonic Rabi oscillations.

Design and analysis of multilayer x ray/XUV microscope

NASA Technical Reports Server (NTRS)

Shealy, David L.

1990-01-01

The design and analysis of a large number of normal incidence multilayer x ray microscopes based on the spherical mirror Schwarzschild configuration is examined. Design equations for the spherical mirror Schwarzschild microscopes are summarized and used to evaluate mirror parameters for microscopes with magnifications ranging from 2 to 50x. Ray tracing and diffraction analyses are carried out for many microscope configurations to determine image resolution as a function of system parameters. The results are summarized in three publication included herein. A preliminary study of advanced reflecting microscope configurations, where aspherics are used in place of the spherical microscope mirror elements, has indicated that the aspherical elements will improve off-axis image resolution and increase the effective field of view.

Delayed progression of diabetic cataractogenesis and retinopathy by Litchi chinensis in STZ-induced diabetic rats.

PubMed

Kilari, Eswar Kumar; Putta, Swathi

2017-03-01

The study was carried out to evaluate the effect of the aqueous fruit pericarp extract of Litchi chinensis (APLC) on parameters which leads to diabetic cataractogenesis and retinopathy in the streptozotocin-induced diabetic rats. The objective of the study is to evaluate the APLC for in vivo antioxidant activity and its role in inhibiting the polyol pathway and formation of advanced glycation end products (AGEs). The diabetic animals were treated with L. chinensis for a period of 12 weeks. At the end of 12 weeks, the animals were killed and the biochemical pathways involved in the pathogenesis of cataract such as oxidative stress by protein content, superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), and polyolpathway by aldose reductase (AR) in lens homogenates, alterations in protein carbonyl content (PCO) and AGEs in both serum and lens the APLC-treated diabetic rats were compared against diabetic control rats. Cataract progression due to hyperglycemia was monitored by slit lamp bio microscope and classified into four stages. Fundoscope test and retinal histopathology were done for assessing retinopathy. Statistically significant reduction in glucose, and elevation of protein content, SOD, CAT, and GSH levels and decreased levels of AR and PCO in lens homogenate and significant reduction in AGEs serum and lens homogenate were observed. Slit lamp examination, fundoscope, and histopathology showed improvement in retinal changes in APLC-treated rats compared to diabetic control animals. The treatment with APLC found to delay the progression of diabetic cataractogenesis and retinopathy, which might be due to its antioxidant activity, because of the presence of active phytochemicals in APLC.

Geraniol modulates tongue and hepatic phase I and phase II conjugation activities and may contribute directly to the chemopreventive activity against experimental oral carcinogenesis.

PubMed

Madankumar, Arumugam; Jayakumar, Subramaniyan; Gokuladhas, Krishnan; Rajan, Balan; Raghunandhakumar, Subramanian; Asokkumar, Selvamani; Devaki, Thiruvengadam

2013-04-05

Xenobiotic metabolizing enzymes are chief determinants in both the susceptibility to mutagenic effect of chemical carcinogens and in the response of tumors to chemotherapy. The present study was aimed to analyze the effect of geraniol administration on the activity of phase I and phase II carcinogen metabolizing enzymes through the nuclear factor erythroid 2-related factor-2 (Nrf2) activation against 4-niroquinoline-1-oxide (4NQO) induced oral carcinogenesis. The well-known chemical carcinogen 4NQO (50 ppm) was used to induce oral carcinogenesis through drinking water for 4, 12, and 20 weeks. The degree of cancer progression at each stage was confirmed by histological examination. At the end of the experimental period, 100% tumor formation was observed in the oral cavity of 4NQO induced animals with significant (P<0.05) alteration in the status of tumor markers, tongue and liver phase I and phase II drug metabolizing enzymes indicating progression of disease. Oral administration of geraniol at the dose of 200 mg/kg b.wt., thrice a week to 4NQO induced animals was able to inhibit tumor formation and thereby delayed the progression of oral carcinogenesis by modulating tongue and liver phase I and phase II drug metabolizing enzymes, as substantiated further by the histological and transmission electron microscopic studies. Our results demonstrate that geraniol exerts its chemopreventive potential by altering activities of phases I and II drug metabolizing enzymes to achieve minimum bioactivation of carcinogen and maximum detoxification. Copyright © 2013 Elsevier B.V. All rights reserved.

Prostate cancer characterization by optical contrast enhanced photoacoustics

NASA Astrophysics Data System (ADS)

Xu, Guan; Qin, Ming; Mukundan, Ananya; Siddiqui, Javed; Takada, Marilia; Vilar-Saavedra, Paulo; Tomlins, Scott A.; Kopelman, Raoul; Wang, Xueding

2016-03-01

During the past decades, prostate cancer (PCa), with an annual incident rate much higher than any other cancer, is the most commonly diagnosed cancer in American men. PCa has a relatively low progression rate yet the survival percentage decreases dramatically once the cancer has metastasized. Identifying aggressive from indolent PCa to prevent metastasis and death is critical to improving outcomes for patients with PCa. Standard procedure for assessing the aggressiveness of PCa involves the removal of tumor tissues by transrectal (TR) ultrasound (US) guided needle biopsy. The microscopic architecture of the biopsied tissue is visualized by histological or immunohistochemical staining procedures. The heterogeneity of the microscopic architecture is characterized by a Gleason score, a quantitative description of the aggressiveness of PCa. Due to the inability to identify the cancer cells, most noninvasive imaging modalities can only provide diagnosis of PCa at limited accuracy. This study investigates the feasibility of identifying PCa tumors and characterizing the aggressiveness of PCa by photoacoustic imaging assisted by cancer targeting polyacrylamide (PAA) nanoparticles (NPs). PAA is a biocompatible material used in clinics for the past 20 years. PAA NPs can protect capsulated optical contrast agents from interference by enzymes and enable prolonged systematic circulation in the living biological environment. The cancer targeting mechanism is achieved by conjugating the NPs to F3 peptides, which trace nucleolin overexpressed on the surface of cancer cells. Preliminary studies have shown that the NPs are capable of staining the PCa cells in vivo.

Micromorphological Aspects of Forensic Geopedology II: Ultramicroscopic vs Microscopic Characterization of Phosphatic Impregnations on Soil Particles in Experimental Burials

NASA Astrophysics Data System (ADS)

Ern, S. I. E.; Trombino, L.; Cattaneo, C.

2012-04-01

Grows up the importance of the role played by soil scientists in the modern forensic sciences, in particular when buried human remains strongly decomposed or skeletonized are found in different environment situations. Among the different techniques normally used in geopedology, it is usefull to apply in such forensic cases, soil micromorphology (including optical microscopy and ultramicroscopy) that has been underused up today, for various kind of reasons. An interdisciplinary Italian-team, formed by earth scientists and legal medicine, is working on several sets of experimental burial of pigs and piglets in different soil types and for different times of burial, in order to get new evidences on environmental behaviour related to the burial, focalising on geopedological and micropedological aspects. The present work is focused on: - ultramicroscopic (SEM-EDS) characterization of the phosphatic impregnation (by body fluids) on soils sampled under the dead bodies of five couples of pigs, buried respectively for one month, six month, one year, two years and two years and half in two different areas; - microscopic (petrographic microscope) and ultramicroscopic (SEM-EDS) cross characterization of the phosphatic impregnation (by body fluids) on soils sampled under the dead bodies of several piglets, buried for twenty months. The first results show trends of persistency of such phosphatic features, mainly related to the grain size of the impregnated soil particles and weather conditions (or seasons) of exhumation, while apparently time since burial is only marginally effective for the investigated burial period. Further experiments are in progress in order to clarify the pathways of phosphorus precipitation and leaching for longer times of burial and different seasons of exhumation, both from the microscopic and the pedological/chemical point of view.

Investigating Students' Mental Models and Knowledge Construction of Microscopic Friction. I. Implications for Curriculum Design and Development

ERIC Educational Resources Information Center

Corpuz, Edgar D.; Rebello, N. Sanjay

2011-01-01

In this paper, we discuss the first phase of a multiphase study aimed at investigating the dynamics of students' knowledge construction in the context of unfamiliar physical phenomenon--microscopic friction. The first phase of this study involved the investigation of the variations in students' mental models of microscopic friction. Clinical…

A phase II study of intraperitoneal radioimmunotherapy with iodine-131-labeled monoclonal antibody OC-125 in patients with residual ovarian carcinoma.

PubMed

Mahé, M A; Fumoleau, P; Fabbro, M; Guastalla, J P; Faurous, P; Chauvot, P; Chetanoud, L; Classe, J M; Rouanet, P; Chatal, J F

1999-10-01

Standard treatment of advanced ovarian cancer is a combination of surgery and chemotherapy. Additional therapies using the i.p. route are considered as a potential means of improving the locoregional control rate. This Phase II study evaluated the efficacy of i.p. radioimmunotherapy (RIT) in patients with minimal residual ovarian adenocarcinoma after primary treatment with surgery and chemotherapy. Between February 1995 and March 1996, six patients with residual macroscopic (<5 mm) or microscopic disease as demonstrated by laparotomy and multiple biopsies received i.p. RIT. All had initial stage III epithelial carcinoma and were treated with debulking surgery and one line (four patients) or two lines (two patients) of chemotherapy. RIT was performed with 60 mg of OC 125 F(ab')2 monoclonal antibody labeled with 4.44 GBq (120 mCi) of 131I injected 5-10 days after the surgical procedure. Systematic laparoscopy or laparotomy with multiple biopsies performed 3 months after RIT in five patients (clinical progression was seen in one patient) showed no change in three patients and progression in two patients. Toxicity was mainly hematological, with grade III neutropenia and thrombocytopenia in two patients. Human antimouse antibody production was demonstrated in all six patients. This study showed little therapeutic benefit from i.p. RIT in patients with residual ovarian carcinoma.

Biophotonics and Bone Biology

NASA Technical Reports Server (NTRS)

Zimmerli, Gregory; Fischer, David; Asipauskas, Marius; Chauhan, Chirag; Compitello, Nicole; Burke, Jamie; Tate, Melissa Knothe

2004-01-01

One of the more serious side effects of extended space flight is an accelerated bone loss. Rates of bone loss are highest in the weight-bearing bones of the hip and spine regions, and the average rate of bone loss as measured by bone mineral density measurements is around 1.2% per month for persons in a microgravity environment. It is well known that bone remodeling responds to mechanical forces. We are developing two-photon microscopy techniques to study bone tissue and bone cell cultures to better understand the fundamental response mechanism in bone remodeling. Osteoblast and osteoclast cell cultures are being studied, and the goal is to use molecular biology techniques in conjunction with Fluorescence Lifetime Imaging Microscopy (FLIM) to study the physiology of in-vitro cell cultures in response to various stimuli, such as fluid flow induced shear stress and mechanical stress. We have constructed a two-photon fluorescence microscope for these studies, and are currently incorporating FLIM detection. Current progress will be reviewed. This work is supported by the NASA John Glenn Biomedical Engineering Consortium.

Live Imaging of Glial Cell Migration in the Drosophila Eye Imaginal Disc

PubMed Central

Cafferty, Patrick; Xie, Xiaojun; Browne, Kristen; Auld, Vanessa J.

2009-01-01

Glial cells of both vertebrate and invertebrate organisms must migrate to final target regions in order to ensheath and support associated neurons. While recent progress has been made to describe the live migration of glial cells in the developing pupal wing (1), studies of Drosophila glial cell migration have typically involved the examination of fixed tissue. Live microscopic analysis of motile cells offers the ability to examine cellular behavior throughout the migratory process, including determining the rate of and changes in direction of growth. Paired with use of genetic tools, live imaging can be used to determine more precise roles for specific genes in the process of development. Previous work by Silies et al. (2) has described the migration of glia originating from the optic stalk, a structure that connects the developing eye and brain, into the eye imaginal disc in fixed tissue. Here we outline a protocol for examining the live migration of glial cells into the Drosophila eye imaginal disc. We take advantage of a Drosophila line that expresses GFP in developing glia to follow glial cell progression in wild type and in mutant animals. PMID:19590493

Osteochondral lesions in developing rats intoxicated with thallium twenty four hours after birth.

PubMed

Barroso-Moguel, R; Villeda-Hernández, J; Méndez-Armenta, M; Ríos, C; Galván-Arzate, S

1992-01-01

An i.p. injection of a solution of thallium acetate in deionized water at a dose of 32 mg/kg, in 24-h-old rats, produces morphological and biochemical alterations in both cartilaginous and osseous tissues. From the beginning, there are alterations in the cartilaginous cell as well as in chrondrine, osteoblasts, osseous tissue and bone marrow. Rats were sacrificed at 24, 48, and 72 h and also at 7 days. Two animals survived for 50 days. One showed total irreversible alopecia while the other one had partial alopecia with discrete recovery. Both showed a low weight and a size of 8 cm. Microscopically, degenerative changes were produced consisting of alteration and death of many cartilaginous cells, uneven metachromasia and the chondrine and decrease of the growth cartilage, scanty bone trabeculae with few osteoblasts. The bone marrow showed few myeloblasts and megakaryocytes. Progressive cellular damage throughout the 50 days of survival represents a response of the thallium ionic accumulation and recycling in cellular mitochondria of all the body's cells. This appeared in our study as irreversible and progressive osteochondral alterations with atrophy of the skin and its adnexa, hyalinization of elastic and collagenous fibers with intense interstitial edema.

Neurotrophic factors and corneal nerve regeneration

PubMed Central

Sacchetti, Marta; Lambiase, Alessandro

2017-01-01

The cornea has unique features that make it a useful model for regenerative medicine studies. It is an avascular, transparent, densely innervated tissue and any pathological changes can be easily detected by slit lamp examination. Corneal sensitivity is provided by the ophthalmic branch of the trigeminal nerve that elicits protective reflexes such as blinking and tearing and exerts trophic support by releasing neuromediators and growth factors. Corneal nerves are easily evaluated for both function and morphology using standard instruments such as corneal esthesiometer and in vivo confocal microscope. All local and systemic conditions that are associated with damage of the trigeminal nerve cause the development of neurotrophic keratitis, a rare degenerative disease. Neurotrophic keratitis is characterized by impairment of corneal sensitivity associated with development of persistent epithelial defects that may progress to corneal ulcer, melting and perforation. Current neurotrophic keratitis treatments aim at supporting corneal healing and preventing progression of corneal damage. Novel compounds able to stimulate corneal nerve recovery are in advanced development stage. Among them, nerve growth factor eye drops showed to be safe and effective in stimulating corneal healing and improving corneal sensitivity in patients with neurotrophic keratitis. Neurotrophic keratitis represents an useful model to evaluate in clinical practice novel neuro-regenerative drugs. PMID:28966630

Programmed cell death progressively models the development of anther sporophytic tissues from the tapetum and is triggered in pollen grains during maturation.

PubMed

Varnier, Anne-Lise; Mazeyrat-Gourbeyre, Florence; Sangwan, Rajbir S; Clément, Christophe

2005-11-01

To characterize the spatial and temporal occurrence of programmed cell death (PCD) in Lilium anther tissues, we used both microscopical and molecular markers of apoptosis for developmental stages from meiosis to pollen release. The first hallmarks of PCD include cell condensation and shrinkage of the cytoplasm, separation of chromatin into delineated masses, and DNA fragmentation in the tapetum as early as the premeiosis stage. PCD then extended to other anther sporophytic tissues, leading to anther dehiscence. Although the PCD clearly affected the endothecium and the epidermis, these two cell layers remained alive until anther dehiscence. In pollen, no sign of PCD was found until pollen mitosis I, after what apoptotic features developed progressively in the vegetative cell. In addition, DNA ladders were detected in all sporophytic tissues and cell types throughout pollen development, whereas in the male gametophyte DNA ladders were only detected during pollen maturation. Our data suggest that PCD is a progressive and active process affecting all the anther tissues, first being triggered in the tapetum.

Progress of projection computed tomography by upgrading of the beamline 37XU of SPring-8

DOE Office of Scientific and Technical Information (OSTI.GOV)

Terada, Yasuko, E-mail: yterada@spring8.or.jp; Suzuki, Yoshio; Uesugi, Kentaro

2016-01-28

Beamline 37XU at SPring-8 has been upgraded for nano-focusing applications. The length of the beamline has been extended to 80 m. By utilizing this length, the beamline has advantages for experiments such as X-ray focusing, X-ray microscopic imaging and X-ray computed tomography. Projection computed tomography measurements were carried out at experimental hutch 3 located 80 m from the light source. CT images of a microcapsule have been successfully obtained with a wide X-ray energy range.

A hybrid scanning force and light microscope for surface imaging and three-dimensional optical sectioning in differential interference contrast.

PubMed

Stemmer, A

1995-04-01

The design of a scanned-cantilever-type force microscope is presented which is fully integrated into an inverted high-resolution video-enhanced light microscope. This set-up allows us to acquire thin optical sections in differential interference contrast (DIC) or polarization while the force microscope is in place. Such a hybrid microscope provides a unique platform to study how cell surface properties determine, or are affected by, the three-dimensional dynamic organization inside the living cell. The hybrid microscope presented in this paper has proven reliable and versatile for biological applications. It is the only instrument that can image a specimen by force microscopy and high-power DIC without having either to translate the specimen or to remove the force microscope. Adaptation of the design features could greatly enhance the suitability of other force microscopes for biological work.

A stereo-compound hybrid microscope for combined intracellular and optical recording of invertebrate neural network activity.

PubMed

Frost, William N; Wang, Jean; Brandon, Christopher J

2007-05-15

Optical recording studies of invertebrate neural networks with voltage-sensitive dyes seldom employ conventional intracellular electrodes. This may in part be due to the traditional reliance on compound microscopes for such work. While such microscopes have high light-gathering power, they do not provide depth of field, making working with sharp electrodes difficult. Here we describe a hybrid microscope design, with switchable compound and stereo objectives, that eases the use of conventional intracellular electrodes in optical recording experiments. We use it, in combination with a voltage-sensitive dye and photodiode array, to identify neurons participating in the swim motor program of the marine mollusk Tritonia. This microscope design should be applicable to optical recording studies in many preparations.

Micropaleontological studies of lunar and terrestrial precambrian materials

NASA Technical Reports Server (NTRS)

Schope, J. W.

1974-01-01

Optical microscopic and scanning electron microscopic studies of rock chips and dust returned by Apollo 14, 15, 16, and 17 are analyzed along with optical microscopic studies of petrographic thin sections of breccias and basalts returned by Apollo 14, 15, and 16. Results show no evidence of modern or fossil lunar organisms. The lunar surface is now, and apparently has been throughout the geologic past, inimical to known biologic systems.

Transmission electron microscopic study of pyrochlore to defect-fluorite transition in rare-earth pyrohafnates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karthik, Chinnathambi, E-mail: Karthikchinnathambi@boisestate.edu; Center for Advanced Energy Studies, 995 University Blvd, Idaho Falls, ID 83415; Anderson, Thomas J.

2012-10-15

A structural transition in rare earth pyrohafnates, Ln{sub 2}Hf{sub 2}O{sub 7} (Ln=Y, La, Pr, Nd, Tb, Dy, Yb and Lu), has been identified. Neutron diffraction showed that the structure transforms from well-ordered pyrochloric to fully fluoritic through the lanthanide series from La to Lu with a corresponding increase in the position parameter x of the 48f (Fd3{sup Macron }m) oxygen site from 0.330 to 0.375. As evidenced by the selected area electron diffraction, La{sub 2}Hf{sub 2}O{sub 7}, Pr{sub 2}Hf{sub 2}O{sub 7} and Nd{sub 2}Hf{sub 2}O{sub 7} exhibited a well-ordered pyrocholoric structure with the presence of intense superlattice spots, which becamemore » weak and diffuse (in Dy{sub 2}Hf{sub 2}O{sub 7} and Tb{sub 2}Hf{sub 2}O{sub 7}) before disappearing completely as the series progressed towards the Lu end. High resolution electron microscopic studies showed the breakdown of the pyrochlore ordering in the form of antiphase domains resulting in diffused smoke-like superlattice spots in the case of Dy{sub 2}Hf{sub 2}O{sub 7} and Tb{sub 2}Hf{sub 2}O{sub 7}. - Graphical abstract: Transmission electron microscopic studies showed the ordered pyrochlore to defect fluorite transition in rare-earth pyrohafnates to occur via the formation of anti-phase domains to start with. Highlights: Black-Right-Pointing-Pointer Pyrochlore to fluorite structural transition in rare earth pyrohafnates. Black-Right-Pointing-Pointer La{sub 2}Hf{sub 2}O{sub 7}, Pr{sub 2}Hf{sub 2}O{sub 7} and Nd{sub 2}Hf{sub 2}O{sub 7} showed well ordered pyrochlore structure. Black-Right-Pointing-Pointer Short range ordering in Dy{sub 2}Hf{sub 2}O{sub 7} and Tb{sub 2}Hf{sub 2}O{sub 7}. Black-Right-Pointing-Pointer Break down of pyrochlore ordering due to antiphase boundaries. Black-Right-Pointing-Pointer Rest of the series showed fluoritic structure.« less

AFM stiffness nanotomography of normal, metaplastic and dysplastic human esophageal cells

NASA Astrophysics Data System (ADS)

Fuhrmann, A.; Staunton, J. R.; Nandakumar, V.; Banyai, N.; Davies, P. C. W.; Ros, R.

2011-02-01

The mechanical stiffness of individual cells is important in tissue homeostasis, cell growth, division and motility, and the epithelial-mesenchymal transition in the initiation of cancer. In this work, a normal squamous cell line (EPC2) and metaplastic (CP-A) as well as dysplastic (CP-D) Barrett's Esophagus columnar cell lines are studied as a model of pre-neoplastic progression in the human esophagus. We used the combination of an atomic force microscope (AFM) with a scanning confocal fluorescence lifetime imaging microscope to study the mechanical properties of single adherent cells. Sixty four force indentation curves were taken over the nucleus of each cell in an 8 × 8 grid pattern. Analyzing the force indentation curves, indentation depth-dependent Young's moduli were found for all cell lines. Stiffness tomograms demonstrate distinct differences between the mechanical properties of the studied cell lines. Comparing the stiffness for indentation forces of 1 nN, most probable Young's moduli were calculated to 4.7 kPa for EPC2 (n = 18 cells), 3.1 kPa for CP-A (n = 10) and 2.6 kPa for CP-D (n = 19). We also tested the influence of nuclei and nucleoli staining organic dyes on the mechanical properties of the cells. For stained EPC2 cells (n = 5), significant stiffening was found (9.9 kPa), while CP-A cells (n = 5) showed no clear trend (2.9 kPa) and a slight softening was observed (2.1 kPa) in the case of CP-D cells (n = 16). Some force-indentation curves show non-monotonic discontinuities with segments of negative slope, resembling a sawtooth pattern. We found the incidence of these 'breakthrough events' to be highest in the dysplastic CP-D cells, intermediate in the metaplastic CP-A cells and lowest in the normal EPC2 cells. This observation suggests that the microscopic explanation for the increased compliance of cancerous and pre-cancerous cells may lie in their susceptibility to 'crumble and yield' rather than their ability to 'bend and flex'.

Histological transformations of the dental pulp as possible indicator of post mortem interval: a pilot study.

PubMed

Carrasco, Patricio A; Brizuela, Claudia I; Rodriguez, Ismael A; Muñoz, Samuel; Godoy, Marianela E; Inostroza, Carolina

2017-10-01

The correct estimation of the post mortem interval (PMI) can be crucial on the success of a forensic investigation. Diverse methods have been used to estimate PMI, considering physical changes that occur after death, such as mortis algor, livor mortis, among others. Degradation after death of dental pulp is a complex process that has not yet been studied thoroughly. It has been described that pulp RNA degradation could be an indicator of PMI, however this study is limited to 6 days. The tooth is the hardest organ of the human body, and within is confined dental pulp. The pulp morphology is defined as a lax conjunctive tissue with great sensory innervation, abundant microcirculation and great presence of groups of cell types. The aim of this study is to describe the potential use of pulp post mortem alterations to estimate PMI, using a new methodology that will allow obtainment of pulp tissue to be used for histomorphological analysis. The current study will identify potential histological indicators in dental pulp tissue to estimate PMI in time intervals of 24h, 1 month, 3 months and 6 months. This study used 26 teeth from individuals with known PMI of 24h, 1 month, 3 months or 6 months. All samples were manipulated with the new methodology (Carrasco, P. and Inostroza C. inventors; Universidad de los Andes, assignee. Forensic identification, post mortem interval estimation and cause of death determination by recovery of dental tissue. United State patent US 61/826,558 23.05.2013) to extract pulp tissue without the destruction of the tooth. The dental pulp tissues obtained were fixed in formalin for the subsequent generation of histological sections, stained with Hematoxylin Eosin and Masson's Trichrome. All sections were observed under an optical microscope using magnifications of 10× and 40×. The microscopic analysis of the samples showed a progressive transformation of the cellular components and fibers of dental pulp along PMI. These results allowed creating a chart of qualitative and quantitative parameters to be used on the estimation on PMI based on microscopic degradation of dental pulp. The histological transformations of dental pulp as a function of time can be used as PMI indicators. Copyright © 2017 Elsevier B.V. All rights reserved.

Recent Progress in Optical Biosensors Based on Smartphone Platforms

PubMed Central

Geng, Zhaoxin; Zhang, Xiong; Fan, Zhiyuan; Lv, Xiaoqing; Su, Yue; Chen, Hongda

2017-01-01

With a rapid improvement of smartphone hardware and software, especially complementary metal oxide semiconductor (CMOS) cameras, many optical biosensors based on smartphone platforms have been presented, which have pushed the development of the point-of-care testing (POCT). Imaging-based and spectrometry-based detection techniques have been widely explored via different approaches. Combined with the smartphone, imaging-based and spectrometry-based methods are currently used to investigate a wide range of molecular properties in chemical and biological science for biosensing and diagnostics. Imaging techniques based on smartphone-based microscopes are utilized to capture microscale analysts, while spectrometry-based techniques are used to probe reactions or changes of molecules. Here, we critically review the most recent progress in imaging-based and spectrometry-based smartphone-integrated platforms that have been developed for chemical experiments and biological diagnosis. We focus on the analytical performance and the complexity for implementation of the platforms. PMID:29068375

Time for a change: is idiopathic pulmonary fibrosis still idiopathic and only fibrotic?

PubMed Central

Wolters, Paul J; Blackwell, Timothy S; Eickelberg, Oliver; Loyd, James E; Kaminski, Naftali; Jenkins, Gisli; Maher, Toby M; Molina-Molina, Maria; Noble, Paul W; Raghu, Ganesh; Richeldi, Luca; Schwarz, Marvin I; Selman, Moises; Wuyts, Wim A; Schwartz, David A

2018-01-01

Idiopathic pulmonary fibrosis (IPF) is a progressive, irreversible, and typically fatal lung disease characterised by subpleural fibrosis, subepithelial fibroblast foci, and microscopic honeycombing. Although understanding of the pathogenic mechanisms continues to evolve, evidence indicates that distal airway and alveolar epithelial cells are central drivers of the disease. In this Viewpoint, we review the history of naming and classifications used to define the disease now referred to as IPF, in the context of understanding the clinical presentation, causes, and pathogenesis of the disease. We aim to generate discussion on whether, given the substantial progress made in understanding the clinical, genetic, cellular, and molecular mechanisms involved in the development of IPF, a change of name should be considered. To initiate this discussion, we offer new suggestions to update the name of this disease and new approaches to classify all forms of pulmonary fibrosis. PMID:29413083

Recent Progress in Optical Biosensors Based on Smartphone Platforms.

PubMed

Geng, Zhaoxin; Zhang, Xiong; Fan, Zhiyuan; Lv, Xiaoqing; Su, Yue; Chen, Hongda

2017-10-25

With a rapid improvement of smartphone hardware and software, especially complementary metal oxide semiconductor (CMOS) cameras, many optical biosensors based on smartphone platforms have been presented, which have pushed the development of the point-of-care testing (POCT). Imaging-based and spectrometry-based detection techniques have been widely explored via different approaches. Combined with the smartphone, imaging-based and spectrometry-based methods are currently used to investigate a wide range of molecular properties in chemical and biological science for biosensing and diagnostics. Imaging techniques based on smartphone-based microscopes are utilized to capture microscale analysts, while spectrometry-based techniques are used to probe reactions or changes of molecules. Here, we critically review the most recent progress in imaging-based and spectrometry-based smartphone-integrated platforms that have been developed for chemical experiments and biological diagnosis. We focus on the analytical performance and the complexity for implementation of the platforms.

Effect of operating microscope light on brain temperature during craniotomy.

PubMed

Gayatri, Parthasarathi; Menon, Girish G; Suneel, Puthuvassery R

2013-07-01

Operating microscopes used during neurosurgery are fitted with xenon light. Burn injuries have been reported because of xenon microscope lighting as the intensity of xenon light is 300 W. We designed this study to find out if the light of operating microscope causes an increase in temperature of the brain tissue, which is exposed underneath. Twenty-one adult patients scheduled for elective craniotomies were enrolled. Distal esophageal temperature (T Eso), brain temperature under the microscope light (T Brain), and brain temperature under dura mater (T Dura) were measured continuously at 15-minute intervals during microscope use. The irrigation fluid temperature, room temperature, intensity of the microscope light, and the distance of the microscope from the brain surface were kept constant. The average age of the patients was 44±15 years (18 males and 3 females). The mean duration of microscope use was 140±39 minutes. There were no significant changes in T Brain and T Dura and T Eso over time. T Dura was significantly lower than T Brain both at time 0 and 60 minutes but not at 90 minutes. T Brain was significantly lower than T Eso both at time 0 and 60 minutes but not at 90 minutes. The T Dura remained significantly lower than T Eso at 0, 60, and 90 minutes. Our study shows that there is no significant rise in brain temperature under xenon microscope light up to 120 minutes duration, at intensity of 60% to 70%, from a distance of 20 to 25 cm from the brain surface.

Scanning-electron-microscope used in real-time study of friction and wear

NASA Technical Reports Server (NTRS)

Brainard, W. A.; Buckley, D. H.

1975-01-01

Small friction and wear apparatus built directly into scanning-electron-microscope provides both dynamic observation and microscopic view of wear process. Friction and wear tests conducted using this system have indicated that considerable information can readily be gained.

Adaptive optics improves multiphoton super-resolution imaging

NASA Astrophysics Data System (ADS)

Zheng, Wei; Wu, Yicong; Winter, Peter; Shroff, Hari

2018-02-01

Three dimensional (3D) fluorescence microscopy has been essential for biological studies. It allows interrogation of structure and function at spatial scales spanning the macromolecular, cellular, and tissue levels. Critical factors to consider in 3D microscopy include spatial resolution, signal-to-noise (SNR), signal-to-background (SBR), and temporal resolution. Maintaining high quality imaging becomes progressively more difficult at increasing depth (where optical aberrations, induced by inhomogeneities of refractive index in the sample, degrade resolution and SNR), and in thick or densely labeled samples (where out-of-focus background can swamp the valuable, in-focus-signal from each plane). In this report, we introduce our new instrumentation to address these problems. A multiphoton structured illumination microscope was simply modified to integrate an adpative optics system for optical aberrations correction. Firstly, the optical aberrations are determined using direct wavefront sensing with a nonlinear guide star and subsequently corrected using a deformable mirror, restoring super-resolution information. We demonstrate the flexibility of our adaptive optics approach on a variety of semi-transparent samples, including bead phantoms, cultured cells in collagen gels and biological tissues. The performance of our super-resolution microscope is improved in all of these samples, as peak intensity is increased (up to 40-fold) and resolution recovered (up to 176+/-10 nm laterally and 729+/-39 nm axially) at depths up to 250 μm from the coverslip surface.

Contribution of collagen and elastin fibers to the mechanical behavior of an abdominal connective tissue.

PubMed

Levillain, A; Orhant, M; Turquier, F; Hoc, T

2016-08-01

The linea alba is a complex structure commonly involved in hernia formation. Knowledge of its mechanical behavior is essential to design suitable meshes and reduce the risk of recurrence. The aim of this study was to investigate the relationships between the mechanical properties of the linea alba and the organization of collagen and elastin fibers. For that purpose, longitudinal and transversal samples were removed from four porcine and three human linea alba, to perform tensile tests under a biphotonic confocal microscope, in each direction. Microscopic observation revealed a tissue composed of two layers, made of transversal collagen fibers in the dorsal side and oblique collagen fibers in the ventral side. This particular architecture led to an anisotropic mechanical behavior, with higher stress in the transversal direction. During loading, oblique fibers of the ventral layer reoriented toward the tensile axis in both directions, while fibers of the dorsal layer remained in the transversal direction. This rotation of oblique fibers progressively increased the stiffness of the tissue and induced a non-linear stress-stretch relation. Elastin fibers formed a layer covering the collagen fibers and followed their movement, suggesting that they ensure their elastic recoil. All of these results demonstrated the strong relationships between the microstructure and the mechanical behavior of the linea alba. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mathematical Modeling of Protein Misfolding Mechanisms in Neurological Diseases: A Historical Overview.

PubMed

Carbonell, Felix; Iturria-Medina, Yasser; Evans, Alan C

2018-01-01

Protein misfolding refers to a process where proteins become structurally abnormal and lose their specific 3-dimensional spatial configuration. The histopathological presence of misfolded protein (MP) aggregates has been associated as the primary evidence of multiple neurological diseases, including Prion diseases, Alzheimer's disease, Parkinson's disease, and Creutzfeldt-Jacob disease. However, the exact mechanisms of MP aggregation and propagation, as well as their impact in the long-term patient's clinical condition are still not well understood. With this aim, a variety of mathematical models has been proposed for a better insight into the kinetic rate laws that govern the microscopic processes of protein aggregation. Complementary, another class of large-scale models rely on modern molecular imaging techniques for describing the phenomenological effects of MP propagation over the whole brain. Unfortunately, those neuroimaging-based studies do not take full advantage of the tremendous capabilities offered by the chemical kinetics modeling approach. Actually, it has been barely acknowledged that the vast majority of large-scale models have foundations on previous mathematical approaches that describe the chemical kinetics of protein replication and propagation. The purpose of the current manuscript is to present a historical review about the development of mathematical models for describing both microscopic processes that occur during the MP aggregation and large-scale events that characterize the progression of neurodegenerative MP-mediated diseases.

Nanomechanical force transducers for biomolecular and intracellular measurements: is there room to shrink and why do it?

PubMed

Sirbuly, Donald J; Friddle, Raymond W; Villanueva, Joshua; Huang, Qian

2015-02-01

Over the past couple of decades there has been a tremendous amount of progress on the development of ultrasensitive nanomechanical instruments, which has enabled scientists to peer for the first time into the mechanical world of biomolecular systems. Currently, work-horse instruments such as the atomic force microscope and optical/magnetic tweezers have provided the resolution necessary to extract quantitative force data from various molecular systems down to the femtonewton range, but it remains difficult to access the intracellular environment with these analytical tools as they have fairly large sizes and complicated feedback systems. This review is focused on highlighting some of the major milestones and discoveries in the field of biomolecular mechanics that have been made possible by the development of advanced atomic force microscope and tweezer techniques as well as on introducing emerging state-of-the-art nanomechanical force transducers that are addressing the size limitations presented by these standard tools. We will first briefly cover the basic setup and operation of these instruments, and then focus heavily on summarizing advances in in vitro force studies at both the molecular and cellular level. The last part of this review will include strategies for shrinking down the size of force transducers and provide insight into why this may be important for gaining a more complete understanding of cellular activity and function.

The Impact of Preradiation Residual Disease Volume on Time to Locoregional Failure in Cutaneous Merkel Cell Carcinoma—A TROG Substudy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Finnigan, Renee; Hruby, George; Wratten, Chris

2013-05-01

Purpose: This study evaluated the impact of margin status and gross residual disease in patients treated with chemoradiation therapy for high-risk stage I and II Merkel cell cancer (MCC). Methods and Materials: Data were pooled from 3 prospective trials in which patients were treated with 50 Gy in 25 fractions to the primary lesion and draining lymph nodes and 2 schedules of carboplatin based chemotherapy. Time to locoregional failure was analyzed according to the burden of disease at the time of radiation therapy, comparing patients with negative margins, involved margins, or macroscopic disease. Results: Analysis was performed on 88 patients,more » of whom 9 had microscopically positive resection margins and 26 had macroscopic residual disease. The majority of gross disease was confined to nodal regions. The 5-year time to locoregional failure, time to distant failure, time to progression, and disease-specific survival rates for the whole group were 73%, 69%, 62%, and 66% respectively. The hazard ratio for macroscopic disease at the primary site or the nodes was 1.25 (95% confidence interval 0.57-2.77), P=.58. Conclusions: No statistically significant differences in time to locoregional failure were identified between patients with negative margins and those with microscopic or gross residual disease. These results must, however, be interpreted with caution because of the limited sample size.« less

Robotic autopositioning of the operating microscope.

PubMed

Oppenlander, Mark E; Chowdhry, Shakeel A; Merkl, Brandon; Hattendorf, Guido M; Nakaji, Peter; Spetzler, Robert F

2014-06-01

Use of the operating microscope has become pervasive since its introduction to the neurosurgical world. Neuronavigation fused with the operating microscope has allowed accurate correlation of the focal point of the microscope and its location on the downloaded imaging study. However, the robotic ability of the Pentero microscope has not been utilized to orient the angle of the microscope or to change its focal length to hone in on a predefined target. To report a novel technology that allows automatic positioning of the operating microscope onto a set target and utilization of a planned trajectory, either determined with the StealthStation S7 by using preoperative imaging or intraoperatively with the microscope. By utilizing the current motorized capabilities of the Zeiss OPMI Pentero microscope, a robotic autopositioning feature was developed in collaboration with Surgical Technologies, Medtronic, Inc. (StealthStation S7). The system is currently being tested at the Barrow Neurological Institute. Three options were developed for automatically positioning the microscope: AutoLock Current Point, Align Parallel to Plan, and Point to Plan Target. These options allow the microscope to pivot around the lesion, hover in a set plane parallel to the determined trajectory, or rotate and point to a set target point, respectively. Integration of automatic microscope positioning into the operative workflow has potential to increase operative efficacy and safety. This technology is best suited for precise trajectories and entry points into deep-seated lesions.

A stereo-compound hybrid microscope for combined intracellular and optical recording of invertebrate neural network activity

PubMed Central

Frost, William N.; Wang, Jean; Brandon, Christopher J.

2007-01-01

Optical recording studies of invertebrate neural networks with voltage-sensitive dyes seldom employ conventional intracellular electrodes. This may in part be due to the traditional reliance on compound microscopes for such work. While such microscopes have high light-gathering power, they do not provide depth of field, making working with sharp electrodes difficult. Here we describe a hybrid microscope design, with switchable compound and stereo objectives, that eases the use of conventional intracellular electrodes in optical recording experiments. We use it, in combination with a voltage-sensitive dye and photodiode array, to identify neurons participating in the swim motor program of the marine mollusk Tritonia. This microscope design should be applicable to optical recording studies in many preparations. PMID:17306887

[Ophthalmologic reading charts : Part 2: Current logarithmically scaled reading charts].

PubMed

Radner, W

2016-12-01

To analyze currently available reading charts regarding print size, logarithmic print size progression, and the background of test-item standardization. For the present study, the following logarithmically scaled reading charts were investigated using a measuring microscope (iNexis VMA 2520; Nikon, Tokyo): Eschenbach, Zeiss, OCULUS, MNREAD (Minnesota Near Reading Test), Colenbrander, and RADNER. Calculations were made according to EN-ISO 8596 and the International Research Council recommendations. Modern reading charts and cards exhibit a logarithmic progression of print sizes. The RADNER reading charts comprise four different cards with standardized test items (sentence optotypes), a well-defined stop criterion, accurate letter sizes, and a high print quality. Numbers and Landolt rings are also given in the booklet. The OCULUS cards have currently been reissued according to recent standards and also exhibit a high print quality. In addition to letters, numbers, Landolt rings, and examples taken from a timetable and the telephone book, sheet music is also offered. The Colenbrander cards use short sentences of 44 characters, including spaces, and exhibit inaccuracy at smaller letter sizes, as do the MNREAD cards. The MNREAD cards use sentences of 60 characters, including spaces, and have a high print quality. Modern reading charts show that international standards can be achieved with test items similar to optotypes, by using recent technology and developing new concepts of test-item standardization. Accurate print sizes, high print quality, and a logarithmic progression should become the minimum requirements for reading charts and reading cards in ophthalmology.

Experimental animal models of encapsulating peritoneal sclerosis.

PubMed

Hoff, Catherine M

2005-04-01

Encapsulating peritoneal sclerosis (EPS) is an infrequent, but extremely serious complication of long-term peritoneal dialysis. The cause of EPS is unclear, but the low incidence suggests that it is most likely multifactorial. The elucidation of developmental pathways and predictive markers of EPS would facilitate the identification and management of high-risk patients. Animal models are often used to define pathways of disease progression and to test strategies for treatment and prevention in the patient population. Ideally such models could help to define the cause of EPS and its developmental pathways, to facilitate the identification of contributing factors and predictive markers, and to provide a system to test therapeutic strategies. Researchers have studied several rodent models of EPS that rely on chronic chemical irritation (for example, bleach, low-pH solution, chlorhexidine gluconate) to induce peritoneal sclerosis and abdominal encapsulation. Development in all models is progressive, with inflammation giving way to peritoneal fibrosis or sclerosis with accumulating membrane damage, culminating in cocoon formation. Microscopic findings are similar to those proposed as diagnostic criteria for clinical EPS: an initial inflammatory infiltrate and submesothelial thickening, collagen deposition, and activation and proliferation of peritoneal fibroblasts. The potential to block progression of peritoneal sclerosis in these models by anti-inflammatory, antifibrotic, and anti-angiogenic agents, and by inhibitors of the renin-angiotensin system have been demonstrated. Animal models based on clinically relevant risk factors (for example, uremia, peritonitis, and long-term exposure to dialysis solutions) now represent the next step in model development.

Brillouin microspectroscopy of nanostructured biomaterials: photonics assisted tailoring mechanical properties

NASA Astrophysics Data System (ADS)

Meng, Zhaokai; Jaiswal, Manish K.; Chitrakar, Chandani; Thakur, Teena; Gaharwar, Akhilesh K.; Yakovlev, Vladislav V.

2016-03-01

Developing new biomaterials is essential for the next-generation of materials for bioenergy, bioelectronics, basic biology, medical diagnostics, cancer research, and regenerative medicine. Specifically, recent progress in nanotechnology has stimulated the development of multifunctional biomaterials for tissue engineering applications. The physical properties of nanocomposite biomaterials, including elasticity and viscosity, play key roles in controlling cell fate, which underlines therapeutic success. Conventional mechanical tests, including uniaxial compression and tension, dynamic mechanical analysis and shear rheology, require mechanical forces to be directly exerted onto the sample and therefore may not be suitable for in situ measurements or continuous monitoring of mechanical stiffness. In this study, we employ spontaneous Brillouin spectroscopy as a viscoelasticity-specific probing technique. We utilized a Brillouin spectrometer to characterize biomaterial's microscopic elasticity and correlated those with conventional mechanical tests (e.g., rheology).

Renal effects of renal x irradiation and induced autoallergic glomerulonephritis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rappaport, D.S.; Casarett, G.W.

1979-09-01

This study was conducted to determine what influence a single large x-ray exposure of kidney has on the development and course of an experimental autoallergic glomerulonephritis (EAG) in rats. EAG was induced in female Sprague-Dawley rats by immunization with Bordetella pertussis vaccine and homogenate of homologous kidney tissue and Freund's complete adjuvant. Progressive arteriolonephrosclerosis (ANS) was observed in right (irradiated) kidneys following unilateral renal irradiation (1500 rad). Rats were either immunized, sham-immunized, irradiated, sham-irradiated, or both immunized and irradiated. Light and immunofluorescent microscopic observation, urine protein content, and kidney weights were evaluated. In immunized-irradiated animals the effects of irradiation andmore » immunization were largely additive. Immunization did not considerably influence the development and course of ANS and irradiation did not considerably influence the development and course of EAG.« less

Investigation on the mechanical properties of palm-based flexible polyurethane foam

NASA Astrophysics Data System (ADS)

On, Ahmad Zuhdi Mohd; Badri, Khairiah Haji

2015-09-01

A series of modification polyurethane (PU) system was prepared by introducing palm kernel based polyol (PKO-p) to progressively replaced commercial polyether polyol from petrochemical based material. This paper describes the effect of PKO-p on the physical-mechanical properties of polyurethane foams. Stress-strain analysis in tensile mode was conducted with physicochemical analysis by performing Fourier transform infrared (FTIR). The morphological studies were observed by the optical microscope. The foam showed an increment on the modulus up to 458.3kPa as more incorporation of PKO-p introduced to the system. In contrast, tensile strength of PU foam depicted the highest up to 162 kPa at 60:40. The elongation at break showed decrement as the composition of the renewable polyol increased to a ratio 60/40 of PKO-p to petrochemical based polyol.

Thermogravimetric and microscopic analysis of SiC/SiC materials with advanced interfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Windisch, C.F. Jr.; Jones, R.H.; Snead, L.L.

1997-04-01

The chemical stability of SiC/SiC composites with fiber/matrix interfaces consisting of multilayers of SiC/SiC and porous SiC have been evaluated using a thermal gravimetric analyzer (TGA). Previous evaluations of SiC/SiC composites with carbon interfacial layers demonstrated the layers are not chemically stable at goal use temperatures of 800-1100{degrees}C and O{sub 2} concentrations greater than about 1 ppm. No measureable mass change was observed for multilayer and porous SiC interfaces at 800-1100{degrees}C and O{sub 2} concentrations of 100 ppm to air; however, the total amount of oxidizable carbon is on the order of the sensitivity of the TGA. Further studies aremore » in progress to evaluate the stability of these materials.« less

SEM analysis of ionizing radiation effects in an analog to digital converter /AD571/

NASA Technical Reports Server (NTRS)

Gauthier, M. K.; Perret, J.; Evans, K. C.

1981-01-01

The considered investigation is concerned with the study of the total-dose degradation mechanisms in an IIL analog to digital (A/D) converter. The A/D converter is a 10 digit device having nine separate functional units on the chip which encompass several hundred transistors and circuit elements. It was the objective of the described research to find the radiation sensitive elements by a systematic search of the devices on the LSI chip. The employed technique using a scanning electron microscope to determine the functional blocks of an integrated circuit which are sensitive to ionizing radiation and then progressively zeroing in on the soft components within those blocks, proved extremely successful on the AD571. Four functional blocks were found to be sensitive to radiation, including the Voltage Reference, DAC, IIL Clock, and IIL SAR.

Assessing the Contributions of Motor Enzymes and Microtubule Dynamics to Mitotic Chromosome Motions.

PubMed

McIntosh, J Richard

2017-10-06

During my graduate work with Keith Porter, I became fascinated by the mitotic spindle, an interest that has motivated much of my scientific work ever since. I began spindle studies by using electron microscopes, instruments that have made significant contributions to our understanding of spindle organization. Such instruments have helped to elucidate the distributions of spindle microtubules, the interactions among them, their molecular polarity, and their associations with both kinetochores and spindle poles. Our lab has also investigated some processes of spindle physiology: microtubule dynamics, the actions of microtubule-associated proteins (including motor enzymes), the character of forces generated by specific spindle components, and factors that control mitotic progression. Here, I give a personal perspective on some of this intellectual history and on what recent discoveries imply about the mechanisms of chromosome motion.

Quantitative High-Resolution Genomic Analysis of Single Cancer Cells

PubMed Central

Hannemann, Juliane; Meyer-Staeckling, Sönke; Kemming, Dirk; Alpers, Iris; Joosse, Simon A.; Pospisil, Heike; Kurtz, Stefan; Görndt, Jennifer; Püschel, Klaus; Riethdorf, Sabine; Pantel, Klaus; Brandt, Burkhard

2011-01-01

During cancer progression, specific genomic aberrations arise that can determine the scope of the disease and can be used as predictive or prognostic markers. The detection of specific gene amplifications or deletions in single blood-borne or disseminated tumour cells that may give rise to the development of metastases is of great clinical interest but technically challenging. In this study, we present a method for quantitative high-resolution genomic analysis of single cells. Cells were isolated under permanent microscopic control followed by high-fidelity whole genome amplification and subsequent analyses by fine tiling array-CGH and qPCR. The assay was applied to single breast cancer cells to analyze the chromosomal region centred by the therapeutical relevant EGFR gene. This method allows precise quantitative analysis of copy number variations in single cell diagnostics. PMID:22140428

Septic implantation syndrome in dogs and cats: a distinct pattern of endophthalmitis with lenticular abscess.

PubMed

Bell, Cynthia M; Pot, Simon A; Dubielzig, Richard R

2013-05-01

To summarize the clinical and pathologic findings in a group of dogs and cats with progressive clinical ocular disease, which were diagnosed with suppurative endophthalmitis and lens capsule rupture. Twenty cats and forty-six dogs that underwent unilateral enucleation or evisceration for intractable uveitis and/or glaucoma. Biopsy submission requests and microscopic case material were evaluated for clinical and histological features, including history of ocular trauma, duration of ocular disease, pattern of inflammation, and the presence of intralenticular microorganisms. The median duration for cats and dogs was 6 and 5 weeks, respectively. A history of trauma was reported for four (20%) cats and 18 (39%) dogs. All confirmed cases of trauma-three in cats and 14 in dogs-were caused by a cat scratch. Microscopically, all cases had suppurative endophthalmitis centered on the lens, lens capsule rupture, cataract, and lenticular abscess. Infectious organisms were identified by Gram stain within the lens of 14 (70%) cats and 30 (65%) dogs. Gram-positive cocci were seen most commonly. Male cats were overrepresented as compared to females. There were no apparent gender, age or breed predilections in dogs. A unique pattern of slowly progressive or delayed-onset endophthalmitis with lens capsule rupture, lenticular abscess, and frequently intralenticular microorganisms is associated with traumatic penetration of the globe and lens capsule. The term Septic Implantation Syndrome (SIS) is favored in lieu of 'phacoclastic uveitis' to avoid confusion with phacolytic uveitis and to clearly implicate the role of intralenticular microorganisms in the pathogenesis. © 2012 American College of Veterinary Ophthalmologists.

Improved cancer risk stratification and diagnosis via quantitative phase microscopy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Liu, Yang; Uttam, Shikhar; Pham, Hoa V.; Hartman, Douglas J.

2017-02-01

Pathology remains the gold standard for cancer diagnosis and in some cases prognosis, in which trained pathologists examine abnormality in tissue architecture and cell morphology characteristic of cancer cells with a bright-field microscope. The limited resolution of conventional microscope can result in intra-observer variation, missed early-stage cancers, and indeterminate cases that often result in unnecessary invasive procedures in the absence of cancer. Assessment of nanoscale structural characteristics via quantitative phase represents a promising strategy for identifying pre-cancerous or cancerous cells, due to its nanoscale sensitivity to optical path length, simple sample preparation (i.e., label-free) and low cost. I will present the development of quantitative phase microscopy system in transmission and reflection configuration to detect the structural changes in nuclear architecture, not be easily identifiable by conventional pathology. Specifically, we will present the use of transmission-mode quantitative phase imaging to improve diagnostic accuracy of urine cytology and the nuclear dry mass is progressively correlate with negative, atypical, suspicious and positive cytological diagnosis. In a second application, we will present the use of reflection-mode quantitative phase microscopy for depth-resolved nanoscale nuclear architecture mapping (nanoNAM) of clinically prepared formalin-fixed, paraffin-embedded tissue sections. We demonstrated that the quantitative phase microscopy system detects a gradual increase in the density alteration of nuclear architecture during malignant transformation in animal models of colon carcinogenesis and in human patients with ulcerative colitis, even in tissue that appears histologically normal according to pathologists. We evaluated the ability of nanoNAM to predict "future" cancer progression in patients with ulcerative colitis.

Concurrent chemotherapy and pelvic radiation therapy compared with pelvic radiation therapy alone as adjuvant therapy after radical surgery in high-risk early-stage cancer of the cervix.

PubMed

Peters, W A; Liu, P Y; Barrett, R J; Stock, R J; Monk, B J; Berek, J S; Souhami, L; Grigsby, P; Gordon, W; Alberts, D S

2000-04-01

To determine whether the addition of cisplatin-based chemotherapy (CT) to pelvic radiation therapy (RT) will improve the survival of early-stage, high-risk patients with cervical carcinoma. Patients with clinical stage IA(2), IB, and IIA carcinoma of the cervix, initially treated with radical hysterectomy and pelvic lymphadenectomy, and who had positive pelvic lymph nodes and/or positive margins and/or microscopic involvement of the parametrium were eligible for this study. Patients were randomized to receive RT or RT + CT. Patients in each group received 49.3 GY RT in 29 fractions to a standard pelvic field. Chemotherapy consisted of bolus cisplatin 70 mg/m(2) and a 96-hour infusion of fluorouracil 1,000 mg/m(2)/d every 3 weeks for four cycles, with the first and second cycles given concurrent to RT. Between 1991 and 1996, 268 patients were entered onto the study. Two hundred forty-three patients were assessable (127 RT + CT patients and 116 RT patients). Progression-free and overall survival are significantly improved in the patients receiving CT. The hazard ratios for progression-free survival and overall survival in the RT only arm versus the RT + CT arm are 2.01 (P =.003) and 1.96 (P =. 007), respectively. The projected progression-free survivals at 4 years is 63% with RT and 80% with RT + CT. The projected overall survival rate at 4 years is 71% with RT and 81% with RT + CT. Grades 3 and 4 hematologic and gastrointestinal toxicity were more frequent in the RT + CT group. The addition of concurrent cisplatin-based CT to RT significantly improves progression-free and overall survival for high-risk, early-stage patients who undergo radical hysterectomy and pelvic lymphadenectomy for carcinoma of the cervix.

Evaluation of a recently developed noncontact specular microscope in comparison with conventional pachymetry devices.

PubMed

Módis, László; Szalai, Eszter; Németh, Gábor; Berta, András

2010-01-01

The study was conducted to assess the central corneal thickness (CCT) of the healthy cornea with a recently developed noncontact specular microscope (EM-3000; Tomey) and compare the results with those measured with a contact specular microscope and an ultrasound pachymeter. Agreement between measurements taken by 2 investigators was also studied. The right eyes of 41 healthy individuals who had negative history of contact lens wear, ophthalmic disease, or ocular surgery were examined. The CCT was determined sequentially with a noncontact specular microscope, a contact specular microscope (EM-1000; Tomey), and an ultrasound pachymeter (AL-2000; Tomey). Each evaluation with the specular microscopes was performed by 2 independent operators. A significant difference was detected in pachymetry measurements among the 3 instruments (p=0.01; analysis of variance). The mean CCT values were lower measured with the ultrasound pachymeter (537+/-30 microm) than the contact endothelial microscope (543+/-37 microm, p=0.17, Student t-test) and the noncontact microscope (549+/-33 microm, p<0.0001) (operator 1). There was no statistically significant difference in CCT measurements between the 2 endothelial microscopes (p=0.19). We found significant correlations (p<0.0001) in thickness measurements between each pair of instruments (r=0.91, noncontact microscopy and ultrasound pachymetry; r=0.74, noncontact and contact microscopy; r=0.72, contact microscopy and ultrasound pachymetry; Spearman rank correlation). The strong correlations among the 3 pachymetry devices suggest that the tested instruments provide reliable measurements; however, they cannot be used interchangeably.

Ethnic Distribution of Microscopic Colitis in the United States.

PubMed

Turner, Kevin; Genta, Robert M; Sonnenberg, Amnon

2015-11-01

A large electronic database of histopathology reports was used to study the ethnic distribution of microscopic colitis in the United States. Miraca Life Sciences is a nation-wide pathology laboratory that receives biopsy specimens submitted by 1500 gastroenterologists distributed throughout the United States. In a case-control study, the prevalence of microscopic colitis in 4 ethnic groups (East Asians, Indians, Hispanics, and Jews) was compared with that of all other ethnic groups (composed of American Caucasians and African Americans), serving as reference group. A total of 11,706 patients with microscopic colitis were included in the analysis. In all ethnic groups alike, microscopic colitis was more common in women than men (78% versus 22%, odds ratio = 3.40, 95% confidence interval = 3.26-3.55). In all ethnic groups, the prevalence of microscopic colitis showed a continuous age-dependent rise. Hispanic patients with microscopic colitis were on average younger than the reference group (59.4 ± 16.2 years versus 64.2 ± 13.8 years, P < 0.001). Jewish patients with microscopic colitis were slightly older than the reference group (65.6 ± 13.4 years, P = 0.015). Compared with the reference group (prevalence = 1.20%), microscopic colitis was significantly less common among patients of Indian (prevalence = 0.28%, odds ratio = 0.32, 95% confidence interval = 0.13-0.65), East Asian (0.22%, 0.19, 0.14-0.26), or Hispanic decent (0.48%, 0.40, 0.36-0.45) and significantly more common among Jewish patients (1.30%, 1.10, 1.01-1.21). Microscopic colitis shows striking variations of its occurrence among different ethnic groups. Such variations could point at differences in the exposure to environmental risk factors.

Note: long-range scanning tunneling microscope for the study of nanostructures on insulating substrates.

PubMed

Molina-Mendoza, Aday J; Rodrigo, José G; Island, Joshua; Burzuri, Enrique; Rubio-Bollinger, Gabino; van der Zant, Herre S J; Agraït, Nicolás

2014-02-01

The scanning tunneling microscope (STM) is a powerful tool for studying the electronic properties at the atomic level, however, it is of relatively small scanning range and the fact that it can only operate on conducting samples prevents its application to study heterogeneous samples consisting of conducting and insulating regions. Here we present a long-range scanning tunneling microscope capable of detecting conducting micro and nanostructures on insulating substrates using a technique based on the capacitance between the tip and the sample and performing STM studies.

High extent of O-GlcNAcylation in breast cancer cells correlates with the levels of HAS enzymes, accumulation of hyaluronan, and poor outcome.

PubMed

Tiainen, Satu; Oikari, Sanna; Tammi, Markku; Rilla, Kirsi; Hämäläinen, Kirsi; Tammi, Raija; Kosma, Veli-Matti; Auvinen, Päivi

2016-11-01

Obesity and oversupply of glucose, e.g., due to nutritional factors may shape the tumor microenvironment favorable for tumor progression. O-GlcNAcylation, a reversible modification of intracellular proteins, influences on several cellular functions and is connected to many diseases including cancer. Glycosaminoglycan hyaluronan (HA) enhances tumor progression and in breast cancer HA accumulation associates strongly with poor outcome. In vitro studies have suggested that O-GlcNAcylation may enhance HA synthesis. The aim of this study was to investigate the correlations between O-GlcNAcylation, HA-related parameters, and disease outcome in a clinical breast cancer material consisting of 278 breast cancer cases. In microscopic analyses, O-GlcNAc staining of the breast carcinoma cells was evaluated in several randomly picked high-power fields of each section. The extent of cytoplasmic O-GlcNAc staining was graded as either low or high according to the intensity of the staining and the percentage of stained cells. The extent of nuclear O-GlcNAc staining was categorized as either low or high according to the percentage of stained nuclei. A high extent of both cytoplasmic and nuclear O-GlcNAcylation correlated with an increased relapse rate, development of distant metastases, and poor outcome. A high extent of cytoplasmic O-GlcNAcylation correlated also with the accumulation of all hyaluronan synthase (HAS1-3) proteins and with a large amount of HA in the tumor stroma. In addition, a high extent of nuclear O-GlcNAcylation associated with obesity. The results suggest a mechanistic association between increased O-GlcNAcylation and HA synthesis, leading to a HA-rich microenvironment favorable for breast cancer progression.

Mangiferin prevents diabetic nephropathy progression and protects podocyte function via autophagy in diabetic rat glomeruli.

PubMed

Wang, Xiaodan; Gao, Lihui; Lin, Hua; Song, Jingling; Wang, Jinwen; Yin, Yumin; Zhao, Jianghu; Xu, Xiangwei; Li, Zhenkun; Li, Ling

2018-04-05

Diabetic nephropathy (DN) is one of the most severe microangiopathies of diabetes mellitus and is a leading cause of end stage renal disease. Numerous studies suggest that podocyte injury contributes to progressive proteinuria. Podocytes are highly specialized, terminally differentiated cells that are unable to proliferate, autophagy plays a key role in maintaining the structure and function of podocytes. Autophagy impairment is involved in the pathogenesis of podocyte loss, which leads to massive proteinuria in DN. In the present study, we investigated the effects of mangiferin on nephropathy in streptozotocin (STZ)-induced diabetic rats; we focused on pathological factors related to autophagy in podocytes and the AMPK-mTOR-ULK1 pathway. The results showed that chronic treatment with mangiferin significantly decreased albuminuria, inhibited glomerular extracellular matrix expansion and restored the expression of nephrin, a podocyte marker, in diabetic rats; these results suggest that mangiferin delayed the process of DN and protected the podocytes. In addition, mangiferin induced autophagy, as shown by the up-regulation of LC3 II and the down-regulation of p62 in both DN rats and podocytes. Transmission electron microscope analyses showed that mangiferin increased the number of autophagosomes in the podocytes of DN rats. This underlying mechanism was associated with the up-regulation of AMPK phosphorylation, the down-regulation of mTOR phosphorylation and the up-regulation of p-ULK1. Taken together, mangiferin delayed the progression of DN and protected the podocytes by enhancing autophagy under diabetic conditions via the AMPK-mTOR-ULK1 pathway. These findings provide new insights into the molecular mechanisms underlying the renoprotective effects of mangiferin in DN. Copyright © 2018 Elsevier B.V. All rights reserved.

Role of histopathology as an aid to prognosis in rhino-orbito-cerebral zygomycosis.

PubMed

Goel, Ashina; Kini, Usha; Shetty, Subhaschandra

2010-01-01

Rhino-orbito-cerebral zygomycosis is a rapidly progressive opportunistic fungal infection characterized by a set of clinical and radiological findings that help in prognostication. The present study is aimed to evaluate its histopathologic features as an aid to prognosis in order to guide the physician at the stage of tissue diagnosis to optimize surgery, chemotherapy and immunosuppression. The study comprises of a microscopic analysis of specific histopathologic variables on 33 cases of zygomycosis that were diagnosed and treated in a seven-year period. Fungal load in the tissue (graded as mild, moderate and marked), mean diameter of fungus, degree of neutrophilic and granulomatous response, tissue invasion and necrosis were graded and assessed for their prognostic significance. Seasonal variation, signs and symptoms, extent of involvement and laboratory parameters were also analyzed to examine the trend of occurrence of the disease and to associate these with patient's outcome, which was categorized as either survived or expired. The follow-up ranged from 1 month to 7 years. Of all the histological variables, angioinvasion was directly related to the mortality rate. Diameter of the fungal hyphae and its intraorbital or intracranial invasion also proved to be significant indicators of poor prognosis. (P = 0.04 and 0.0037, respectively) though angioinvasion was directly related to the mortality rate. Thus, histopathology could assist the clinician in assessing patient's progress and thus optimize the treatment in such patients.

Influence of chamber type integrated with computer-assisted semen analysis (CASA) system on the results of boar semen evaluation.

PubMed

Gączarzewicz, D

2015-01-01

The objective of the study was to evaluate the effect of different types of chambers used in computer-assisted semen analysis (CASA) on boar sperm concentration and motility parameters. CASA measurements were performed on 45 ejaculates by comparing three commonly used chambers: Leja chamber (LJ), Makler chamber (MK) and microscopic slide-coverslip (SL). Concentration results obtained with CASA were verified by manual counting on a Bürker hemocytometer (BH). No significant differences were found between the concentrations determined with BH vs. LJ and SL, whereas higher (p<0.01) values of this parameter were obtained with MK. Compared to MK and SL, significantly higher values were recorded in LJ for velocity (VCL and VAP) as well as amplitude of the lateral head displacement (ALH) and beat cross frequency (BCF), which was associated with significantly higher percentages of motile, progressively motile and rapidly progressive motile spermatozoa. Higher values for the linearity (LIN) and straightness (STR) of sperm movement were obtained for the analysis performed in MK and SL. In both these chambers, the results of all the linearity and kinetic parameters of sperm were similar (p>0.05). The results obtained show that CASA assessment of boar semen should account for the effect of counting chamber on the results of sperm motility and concentration, which confirms the need for further study on standardizing the automatic analysis of boar semen.

Low cost label-free live cell imaging for biological samples

NASA Astrophysics Data System (ADS)

Seniya, C.; Towers, C. E.; Towers, D. P.

2017-02-01

This paper reports the progress to develop a practical phase measuring microscope offering new capabilities in terms of phase measurement accuracy and quantification of cell:cell interactions over the longer term. A novel, low cost phase interference microscope for imaging live cells (label-free) is described. The method combines the Zernike phase contrast approach with a dual mirror design to enable phase modulation between the scattered and un-scattered optical fields. Two designs are proposed and demonstrated, one of which retains the common path nature of Zernike's original microscopy concept. In both setups the phase shift is simple to control via a piezoelectric driven mirror in the back focal plane of the imaging system. The approach is significantly cheaper to implement than those based on spatial light modulators (SLM) at approximately 20% of the cost. A quantitative assessment of the performance of a set of phase shifting algorithms is also presented, specifically with regard to broad bandwidth illumination in phase contrast microscopy. The simulation results show that the phase measurement accuracy is strongly dependent on the algorithm selected and the optical path difference in the sample.

Community structure of free-floating filamentous cyanobacterial mats from the Wonder Lake geothermal springs in the Philippines.

PubMed

Lacap, Donnabella C; Smith, Gavin J D; Warren-Rhodes, Kimberley; Pointing, Stephen B

2005-07-01

Cyanobacterial mats were characterized from pools of 45-60 degrees C in near-neutral pH, low-sulphide geothermal springs in the Philippines. Mat structure did not vary with temperature. All mats possessed highly ordered layers of airspaces at both the macroscopic and microscopic level, and these appear to be an adaptation to a free-floating growth habit. Upper mat layers supported biomass with elevated carotenoid:chlorophyll a ratios and an as yet uncharacterized waxy layer on the dorsal surface. Microscopic examination revealed mats comprised a single Fischerella morphotype, with abundant heterocysts throughout mats at all temperatures. Molecular analysis of mat community structure only partly matched morphological identification. All samples supported greater 16S rDNA-defined diversity than morphology suggested, with a progressive loss in the number of genotypes with increasing temperature. Fischerella-like sequences were recovered from mats occurring at all temperatures, but some mats also yielded Oscillatoria-like sequences, although corresponding phenotypes were not observed. Phylogenetic analysis revealed that Fischerella-like sequences were most closely affiliated with Fischerella major and the Oscillatoria-like sequences with Oscillatoria amphigranulata.

Open-source image reconstruction of super-resolution structured illumination microscopy data in ImageJ

PubMed Central

Müller, Marcel; Mönkemöller, Viola; Hennig, Simon; Hübner, Wolfgang; Huser, Thomas

2016-01-01

Super-resolved structured illumination microscopy (SR-SIM) is an important tool for fluorescence microscopy. SR-SIM microscopes perform multiple image acquisitions with varying illumination patterns, and reconstruct them to a super-resolved image. In its most frequent, linear implementation, SR-SIM doubles the spatial resolution. The reconstruction is performed numerically on the acquired wide-field image data, and thus relies on a software implementation of specific SR-SIM image reconstruction algorithms. We present fairSIM, an easy-to-use plugin that provides SR-SIM reconstructions for a wide range of SR-SIM platforms directly within ImageJ. For research groups developing their own implementations of super-resolution structured illumination microscopy, fairSIM takes away the hurdle of generating yet another implementation of the reconstruction algorithm. For users of commercial microscopes, it offers an additional, in-depth analysis option for their data independent of specific operating systems. As a modular, open-source solution, fairSIM can easily be adapted, automated and extended as the field of SR-SIM progresses. PMID:26996201

Construction of a Quantum Matter Synthesizer

NASA Astrophysics Data System (ADS)

Trisnadi, Jonathan; McDonald, Mickey; Chin, Cheng

2017-04-01

We report progress on the construction of a new platform to manipulate ultracold atoms. The ``Quantum Matter Synthesizer (QMS)'' will have the capability of deterministically preparing large 2D arrays of atoms with single site addressability. Cesium atoms are first transferred into a science cell (specially textured to reduce reflectance to 0.1% across a wide range of wavelengths and incident angles) via a moving 1D lattice, where they are loaded into a magic-wavelength, far-detuned 2D optical lattice. Two NA=0.8 microscope objectives surround the science cell from above and below. The lower objective will be used to project an array of optical tweezers created via a digital micromirror device (DMD) onto the atom-trapping plane, which will be used to rearrange atoms into a desired configuration after first taking a site-resolved fluorescence image of the initial atomic distribution with the upper objective. We provide updates on our magnetic-optical trap and Raman-sideband cooling performance, characterization of the resolution of our microscope objectives, and stability tests for the objective mounting structure.

Looking for Changes in Soil over Time

NASA Technical Reports Server (NTRS)

2006-01-01

The grinding teeth have worn away on the rock abrasion tool of NASA's Mars Exploration Rover Spirit (after exposing interiors of five time more rock targets than its design goal of three rocks) but the tool still has useful wire bristles for brushing targets. In this image, a figure-eight-like imprint in the Martian soil marks the spot where Spirit has begun examining subsurface deposits layer by layer. The circular indentations resulted from brushing by the rock abrasion tool, one of several instruments on the rover's robotic arm. As an effective brushing tool it is now fulfilling a soil profiling experiment on a target called 'Progress.'

The experiment is a multi-step process of carefully brushing away fine layers of soil and then using the Moessbauer and alpha particle X-ray spectrometers, microscopic imager, and panoramic camera to examine the exposed surfaces during the long Martian winter.

This view is a mosaic of exposures taken by Spirit's microscopic imager during the rover's 830th Martian day (May 4, 2006). The total area shown is about 6 centimeters (2.4 inches) square.

Quantitative phase imaging of platelet: assessment of cell morphology and function

NASA Astrophysics Data System (ADS)

Vasilenko, Irina; Vlasova, Elizaveta; Metelin, Vladislav; Agadzhanjan, B.; Lyfenko, R.

2017-02-01

It is well known that platelets play a central role in hemostasis and thrombosis, they also mediate tumor cell growth, dissemination and angiogenesis. The purpose of the present experiment was to evaluate living platelet size, function and morphology simultaneously in unactivated and activated states using Phase-Interference Microscope "Cytoscan" (Moscow, Russia). We enrolled 30 healthy volunteers, who had no past history of aeteriosclerosis-related disorders, such as coronary heart disease, cerebrovascular disease, hypertention, diabetes or hyperlipidemia and 30 patients with oropharynx cancer. We observed the optic-geometrical parameters of each isolated living cell and the distribution of platelets by sizes have been analysed to detect the dynamics of cell population heterogeneity. Simultaneously we identified 4 platelet forms that have different morphological features and different parameters of size distribution. We noticed that morphological platelet types correlate with morphometric platelet parameters. The data of polymorphisms of platelet reactivity in tumor progression can be used to improve patient outcomes in the cancer prevention and treatment. Moreover morphometric and functional platelet parameters can serve criteria of the efficiency of the radio- and chemotherapy carried out. In conclusion the computer phase-interference microscope provides rapid and effective analysis of living platelet morphology and function at the same time. The use of the computer phase-interference microscope could be an easy and fast method to check the state of platelets in patients with changed platelet activation and to follow a possible pharmacological therapy to reduce this phenomenon.

Openstage: A Low-Cost Motorized Microscope Stage with Sub-Micron Positioning Accuracy

PubMed Central

Campbell, Robert A. A.; Eifert, Robert W.; Turner, Glenn C.

2014-01-01

Recent progress in intracellular calcium sensors and other fluorophores has promoted the widespread adoption of functional optical imaging in the life sciences. Home-built multiphoton microscopes are easy to build, highly customizable, and cost effective. For many imaging applications a 3-axis motorized stage is critical, but commercially available motorization hardware (motorized translators, controller boxes, etc) are often very expensive. Furthermore, the firmware on commercial motor controllers cannot easily be altered and is not usually designed with a microscope stage in mind. Here we describe an open-source motorization solution that is simple to construct, yet far cheaper and more customizable than commercial offerings. The cost of the controller and motorization hardware are under $1000. Hardware costs are kept low by replacing linear actuators with high quality stepper motors. Electronics are assembled from commonly available hobby components, which are easy to work with. Here we describe assembly of the system and quantify the positioning accuracy of all three axes. We obtain positioning repeatability of the order of in X/Y and in Z. A hand-held control-pad allows the user to direct stage motion precisely over a wide range of speeds ( to ), rapidly store and return to different locations, and execute “jumps” of a fixed size. In addition, the system can be controlled from a PC serial port. Our “OpenStage” controller is sufficiently flexible that it could be used to drive other devices, such as micro-manipulators, with minimal modifications. PMID:24586468

Thermal magnetic field noise limits resolution in transmission electron microscopy.

PubMed

Uhlemann, Stephan; Müller, Heiko; Hartel, Peter; Zach, Joachim; Haider, Max

2013-07-26

The resolving power of an electron microscope is determined by the optics and the stability of the instrument. Recently, progress has been obtained towards subångström resolution at beam energies of 80 kV and below but a discrepancy between the expected and achieved instrumental information limit has been observed. Here we show that magnetic field noise from thermally driven currents in the conductive parts of the instrument is the root cause for this hitherto unexplained decoherence phenomenon. We demonstrate that the deleterious effect depends on temperature and at least weakly on the type of material.

Understanding Core-Collapse Supernovae

NASA Astrophysics Data System (ADS)

Hix, W. R.; Lentz, E. J.; Baird, M.; Messer, O. E. B.; Mezzacappa, A.; Lee, C.-T.; Bruenn, S. W.; Blondin, J. M.; Marronetti, P.

2010-03-01

Our understanding of core-collapse supernovae continues to improve as better microphysics is included in increasingly realistic neutrino-radiationhydrodynamic simulations. Recent multi-dimensional models with spectral neutrino transport, which slowly develop successful explosions for a range of progenitors between 12 and 25 solar mass, have motivated changes in our understanding of the neutrino reheating mechanism. In a similar fashion, improvements in nuclear physics, most notably explorations of weak interactions on nuclei and the nuclear equation of state, continue to refine our understanding of how supernovae explode. Recent progresses on both the macroscopic and microscopic effects that affect core-collapse supernovae are discussed.

Postdoctoral Fellow | Center for Cancer Research

Cancer.gov

The lab is interested in understanding the regulation of RNA localization by cancer-associated proteins and the contribution of localized RNAs to tumor progression. The work relies on a variety of cell biological, microscopical and biochemical approaches in 2D and 3D cell culture systems. Some of the current projects aim to investigate the effect of the mechanical properties of the extracellular matrix on RNA localization, and the coupling between RNA localization and translation using single-molecule imaging approaches. This research program is funded by the NIH Intramural Research Program and is supported by state-of-the-art facilities on the NIH campus.

Developments in Scanning Hall Probe Microscopy

NASA Astrophysics Data System (ADS)

Chouinard, Taras; Chu, Ricky; David, Nigel; Broun, David

2009-05-01

Low temperature scanning Hall probe microscopy is a sensitive means of imaging magnetic structures with high spatial resolution and magnetic flux sensitivity approaching that of a Superconducting Quantum Interference Device. We have developed a scanning Hall probe microscope with novel features, including highly reliable coarse positioning, in situ optimization of sensor-sample alignment and capacitive transducers for linear, long range positioning measurement. This has been motivated by the need to reposition accurately above fabricated nanostructures such as small superconducting rings. Details of the design and performance will be presented as well as recent progress towards time-resolved measurements with sub nanosecond resolution.

Pearson disease in an infant presenting with severe hypoplastic anemia, normal pancreatic function, and progressive liver failure.

PubMed

Shapira, Adi; Konopnicki, Muriel; Hammad-Saied, Mohammed; Shabad, Evelyn

2014-07-01

Pearson disease is a rare, usually fatal, mitochondrial disorder affecting primarily the bone marrow and the exocrine pancreas. We report a previously healthy 10-week-old girl who presented with profound macrocytic anemia followed by pancytopenia, synthetic liver dysfunction with liver steatosis, and metabolic acidosis with high lactate levels. She had no pancreatic involvement. Multiple cytoplasmic vacuoles in myelocytes and monocytes were seen upon microscopic evaluation of the bone marrow. Genetic analysis of the mitochondrial genome revealed a 5 kbp deletion, thus establishing the diagnosis of Pearson disease.

Availability of a library of infrared (2.1-25.0 microns) mineral spectra

NASA Technical Reports Server (NTRS)

Salisbury, John W.; Vergo, Norma; Walter, Louis S.

1989-01-01

All previously published libraries of infrared mineral spectra are in the form of transmitance. Reflectance spectra are, however, more useful for remote sensing and some potential laboratory applications, such as the use of an infrared microscope for mineral identification on polished sections. This note points out that construction of a new library of infrared (2.1-25.0 microns) mineral spectra is in progress. Both transmittance and reflectance measurements of a selection of 63 different, well-characterized minerals have been published to date. These data are available in both hard copy and digital form.

Efficient coarse simulation of a growing avascular tumor

PubMed Central

Kavousanakis, Michail E.; Liu, Ping; Boudouvis, Andreas G.; Lowengrub, John; Kevrekidis, Ioannis G.

2013-01-01

The subject of this work is the development and implementation of algorithms which accelerate the simulation of early stage tumor growth models. Among the different computational approaches used for the simulation of tumor progression, discrete stochastic models (e.g., cellular automata) have been widely used to describe processes occurring at the cell and subcell scales (e.g., cell-cell interactions and signaling processes). To describe macroscopic characteristics (e.g., morphology) of growing tumors, large numbers of interacting cells must be simulated. However, the high computational demands of stochastic models make the simulation of large-scale systems impractical. Alternatively, continuum models, which can describe behavior at the tumor scale, often rely on phenomenological assumptions in place of rigorous upscaling of microscopic models. This limits their predictive power. In this work, we circumvent the derivation of closed macroscopic equations for the growing cancer cell populations; instead, we construct, based on the so-called “equation-free” framework, a computational superstructure, which wraps around the individual-based cell-level simulator and accelerates the computations required for the study of the long-time behavior of systems involving many interacting cells. The microscopic model, e.g., a cellular automaton, which simulates the evolution of cancer cell populations, is executed for relatively short time intervals, at the end of which coarse-scale information is obtained. These coarse variables evolve on slower time scales than each individual cell in the population, enabling the application of forward projection schemes, which extrapolate their values at later times. This technique is referred to as coarse projective integration. Increasing the ratio of projection times to microscopic simulator execution times enhances the computational savings. Crucial accuracy issues arising for growing tumors with radial symmetry are addressed by applying the coarse projective integration scheme in a cotraveling (cogrowing) frame. As a proof of principle, we demonstrate that the application of this scheme yields highly accurate solutions, while preserving the computational savings of coarse projective integration. PMID:22587128

Virtual reality microscope versus conventional microscope regarding time to diagnosis: an experimental study.

PubMed

Randell, Rebecca; Ruddle, Roy A; Mello-Thoms, Claudia; Thomas, Rhys G; Quirke, Phil; Treanor, Darren

2013-01-01

  To create and evaluate a virtual reality (VR) microscope that is as efficient as the conventional microscope, seeking to support the introduction of digital slides into routine practice.   A VR microscope was designed and implemented by combining ultra-high-resolution displays with VR technology, techniques for fast interaction, and high usability. It was evaluated using a mixed factorial experimental design with technology and task as within-participant variables and grade of histopathologist as a between-participant variable. Time to diagnosis was similar for the conventional and VR microscopes. However, there was a significant difference in the mean magnification used between the two technologies, with participants working at a higher level of magnification on the VR microscope.   The results suggest that, with the right technology, efficient use of digital pathology for routine practice is a realistic possibility. Further work is required to explore what magnification is required on the VR microscope for histopathologists to identify diagnostic features, and the effect on this of the digital slide production process. © 2012 Blackwell Publishing Limited.

Scanning electron microscope fine tuning using four-bar piezoelectric actuated mechanism

NASA Astrophysics Data System (ADS)

Hatamleh, Khaled S.; Khasawneh, Qais A.; Al-Ghasem, Adnan; Jaradat, Mohammad A.; Sawaqed, Laith; Al-Shabi, Mohammad

2018-01-01

Scanning Electron Microscopes are extensively used for accurate micro/nano images exploring. Several strategies have been proposed to fine tune those microscopes in the past few years. This work presents a new fine tuning strategy of a scanning electron microscope sample table using four bar piezoelectric actuated mechanisms. The introduced paper presents an algorithm to find all possible inverse kinematics solutions of the proposed mechanism. In addition, another algorithm is presented to search for the optimal inverse kinematic solution. Both algorithms are used simultaneously by means of a simulation study to fine tune a scanning electron microscope sample table through a pre-specified circular or linear path of motion. Results of the study shows that, proposed algorithms were able to minimize the power required to drive the piezoelectric actuated mechanism by a ratio of 97.5% for all simulated paths of motion when compared to general non-optimized solution.

Remote Histology Learning from Static versus Dynamic Microscopic Images

ERIC Educational Resources Information Center

Mione, Sylvia; Valcke, Martin; Cornelissen, Maria

2016-01-01

Histology is the study of microscopic structures in normal tissue sections. Curriculum redesign in medicine has led to a decrease in the use of optical microscopes during practical classes. Other imaging solutions have been implemented to facilitate remote learning. With advancements in imaging technologies, learning material can now be digitized.…

Electron Microscope Center Opens at Berkeley.

ERIC Educational Resources Information Center

Robinson, Arthur L.

1981-01-01

A 1.5-MeV High Voltage Electron Microscope has been installed at the Lawrence Berkeley Laboratory which will help materials scientists and biologists study samples in more true-to-life situations. A 1-MeV Atomic Resolution Microscope will be installed at the same location in two years which will allow scientists to distinguish atoms. (DS)

Automatic analysis for neuron by confocal laser scanning microscope

NASA Astrophysics Data System (ADS)

Satou, Kouhei; Aoki, Yoshimitsu; Mataga, Nobuko; Hensh, Takao K.; Taki, Katuhiko

2005-12-01

The aim of this study is to develop a system that recognizes both the macro- and microscopic configurations of nerve cells and automatically performs the necessary 3-D measurements and functional classification of spines. The acquisition of 3-D images of cranial nerves has been enabled by the use of a confocal laser scanning microscope, although the highly accurate 3-D measurements of the microscopic structures of cranial nerves and their classification based on their configurations have not yet been accomplished. In this study, in order to obtain highly accurate measurements of the microscopic structures of cranial nerves, existing positions of spines were predicted by the 2-D image processing of tomographic images. Next, based on the positions that were predicted on the 2-D images, the positions and configurations of the spines were determined more accurately by 3-D image processing of the volume data. We report the successful construction of an automatic analysis system that uses a coarse-to-fine technique to analyze the microscopic structures of cranial nerves with high speed and accuracy by combining 2-D and 3-D image analyses.

Imaging of Norway spruce early somatic embryos with the ESEM, Cryo-SEM and laser scanning microscope.

PubMed

Neděla, Vilém; Hřib, Jiří; Havel, Ladislav; Hudec, Jiří; Runštuk, Jiří

2016-05-01

This article describes the surface structure of Norway spruce early somatic embryos (ESEs) as a typical culture with asynchronous development. The microstructure of extracellular matrix covering ESEs were observed using the environmental scanning electron microscope as a primary tool and using the scanning electron microscope with cryo attachment and laser electron microscope as a complementary tool allowing our results to be proven independently. The fresh samples were observed in conditions of the air environment of the environmental scanning electron microscope (ESEM) with the pressure from 550Pa to 690Pa and the low temperature of the sample from -18°C to -22°C. The samples were studied using two different types of detector to allow studying either the thin surface structure or material composition. The scanning electron microscope with cryo attachment was used for imaging frozen extracellular matrix microstructure with higher resolution. The combination of both electron microscopy methods was suitable for observation of "native" plant samples, allowing correct evaluation of our results, free of error and artifacts. Copyright © 2016 Elsevier Ltd. All rights reserved.

Semen characteristics and selected biochemical markers of canine seminal plasma in various seasons of the year.

PubMed

Strzeżek, R; Szemplińska, K; Filipowicz, K; Kordan, W

2015-01-01

The aim of this study was to evaluate the influence of season on selected qualitative semen characteristics and biochemical markers of canine seminal plasma. Whole ejaculates were collected from 5 crossbred dogs aged 2-8 years. The study covered a period of one year divided into four seasons: spring (March, April, May), summer (June, July, August), autumn (September, October, November) and winter (December, January, February). Semen samples were subjected to macroscopic and microscopic analyses to determine semen volume, total sperm counts and sperm morphology parameters. The study also involved the determination of sperm motility parameters (CASA system), sperm plasma membrane integrity (SPMI, fluorescent staining SYBR-14/PI), sperm mitochondrial membrane potential (MMP, fluorescent staining JC-1/PI) and the ATP content of sperm cells. Total protein content (TPC) and the activity of alkaline phosphatase (AP) and acid phosphatase (AcP) were determined in biochemical analyses of seminal plasma. No significant differences in ejaculate volume, SMPI or ATP content of sperm cells were observed between seasons. The highest total sperm counts were reported in ejaculates acquired in summer and autumn. The lowest MMP values were determined in summer ejaculates. No significant differences in sperm motility (MOT) were observed throughout the experiment, but ejaculates collected in autumn and winter were characterized by the highest progressive motility (PMOT). AP activity and TPC were not significantly affected by season. However, AcP activity levels were significantly lower in autumn than in the remaining seasons. Seasonal variations in the analyzed macroscopic and microscopic parameters of ejaculates and biochemical markers of seminal plasma did not exert a clear negative effect on the quality of canine semen.

Function of oval cells in hepatocellular carcinoma in rats.

PubMed

Fang, Chi-Hua; Gong, Jia-Qing; Zhang, Wei

2004-09-01

To study oval cells' pathological characteristics and relationship with the occurrence of hepatocellular carcinoma (HCC); to observe the form and structural characteristics of oval cells; to explore the expression characteristics of C-kit, PCNA mRNA and c-myc gene during the occurrence and development of HCC and the effect of ulinastatin (UTI) on C-kit and PCNA expression. One hundred and twenty-five SD rats fed on 3,3'-diaminobenzidine (DAB) to construct HCC models were divided into control group, cancer-inducing group and UTI intervention group. In each group, rat liver samples were collected at weeks 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22 and 24 respectively to study pathological distribution characteristics of oval cells in the process of carcinogenesis under optical microscope. Oval cells were separated by the methods of improved density gradient centrifugation and their structural characteristics were observed under optical microscope and electronic microscope respectively; the oval cells expressing C-kit and PCNA in the collected samples were observed by the methods of immunohistochemistry and image analysis and the expression of c-myc mRNA was also detected by reverse transcription polymerase chain reaction (RT-PCR). Oval cells proliferated firstly in the portal area then gradually migrated into hepatic parenchyma in the inducing group and intervention group. The oval cells distributed inside and outside the carcinoma nodes. The oval cells presented the characteristics of undifferentiated cells: a high ratio of nucleolus and cellular plasm and obvious nucleoli, rare organelle in plasm. Only a few mitochondria and endoplasmic reticulum and some villus-like apophysis on surface of cells could be seen. Cells stained with C-kit and PCNA antibody were mainly oval cells distributed in the portal area. The expression of c-myc mRNA increased with the progression of HCC. However, in the intervention group, UTI could retard its increase. Oval cells work throughout the development of HCC, and might play important roles in this process. c-myc gene may be a kind of promoter gene of HCC, and play a key role in hepatic injury and development of HCC. UTI could retard the occurrence of HCC. Copyright 2004 The WJG Press ISSN

Function of oval cells in hepatocellular carcinoma in rats

PubMed Central

Fang, Chi-Hua; Gong, Jia-Qing; Zhang, Wei

2004-01-01

AIM: To study oval cells pathological characteristics and relationship with the occurrence of hepatocellular carcinoma (HCC); to observe the form and structural characteristics of oval cells; to explore the expression characteristics of C-kit, PCNA mRNA and c-myc gene during the occurrence and development of HCC and the effect of ulinastatin (UTI) on C-kit and PCNA expression. METHODS: One hundred and twenty-five SD rats fed on 3,3'-diaminobenzidine (DAB) to construct HCC models were divided into control group, cancer-inducing group and UTI intervention group. In each group, rat liver samples were collected at weeks 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22 and 24 respectively to study pathological distribution characteristics of oval cells in the process of carcinogenesis under optical microscope. Oval cells were separated by the methods of improved density gradient centrifugation and their structural characteristics were observed under optical microscope and electronic microscope respectively; the oval cells expressing C-kit and PCNA in the collected samples were observed by the methods of immunohistochemistry and image analysis and the expression of c-myc mRNA was also detected by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Oval cells proliferated firstly in the portal area then gradually migrated into hepatic parenchyma in the inducing group and intervention group. The oval cells distributed inside and outside the carcinoma nodes. The oval cells presented the characteristics of undifferentiated cells: a high ratio of nucleolus and cellular plasm and obvious nucleoli, rare organelle in plasm. Only a few mitochondria and endoplasmic reticulum and some villus-like apophysis on surface of cells could be seen. Cells stained with C-kit and PCNA antibody were mainly oval cells distributed in the portal area. The expression of c-myc mRNA increased with the progression of HCC. However, in the intervention group, UTI could retard its increase. CONCLUSION: Oval cells work throughout the development of HCC, and might play important roles in this process. c-myc gene may be a kind of promoter gene of HCC, and play a key role in hepatic injury and development of HCC. UTI could retard the occurrence of HCC. PMID:15300889

Mechanically adjustable single-molecule transistors and stencil mask nanofabrication of high-resolution scanning probes

NASA Astrophysics Data System (ADS)

Champagne, Alexandre

This dissertation presents the development of two original experimental techniques to probe nanoscale objects. The first one studies electronic transport in single organic molecule transistors in which the source-drain electrode spacing is mechanically adjustable. The second involves the fabrication of high-resolution scanning probe microscopy sensors using a stencil mask lithography technique. We describe the fabrication of transistors in which a single organic molecule can be incorporated. The source and drain leads of these transistors are freely suspended above a flexible substrate, and their spacing can be adjusted by bending the substrate. We detail the technology developed to carry out measurements on these samples. We study electronic transport in single C60 molecules at low temperature. We observe Coulomb blockaded transport and can resolve the discrete energy spectrum of the molecule. We are able to mechanically tune the spacing between the electrodes (over a range of 5 A) to modulate the lead-molecule coupling, and can electrostatically tune the energy levels on the molecule by up to 160 meV using a gate electrode. Initial progress in studying different transport regimes in other molecules is also discussed. We present a lithographic process that allows the deposition of metal nanostructures with a resolution down to 10 nm directly onto atomic force microscope (AFM) tips. We show that multiple layers of lithography can be deposited and aligned. We fabricate high-resolution magnetic force microscopy (MFM) probes using this method and discuss progress to fabricate other scanning probe microscopy (SPM) sensors.

Progressing single biomolecule force spectroscopy measurements for the screening of DNA binding agents

NASA Astrophysics Data System (ADS)

Zhang, Wenke; Barbagallo, Romina; Madden, Claire; Roberts, Clive J.; Woolford, Alison; Allen, Stephanie

2005-10-01

Recent studies have indicated that the force-extension properties of single molecules of double stranded (ds) DNA are sensitive to the presence of small molecule DNA binding agents, and also to their mode of binding. These observations raise the possibility of using this approach as a highly sensitive tool for the screening of such agents. However, particularly for studies employing the atomic force microscope (AFM), several non-trivial barriers hinder the progress of this approach to the non-specialist arena and hence also the full realization of this possibility. In this paper, we therefore address a series of key reproducibility and metrological issues associated with this type of measurement. Specifically, we present an improved immobilization method that covalently anchors one end (5' end) of a dual labelled (5'-thiol, 3'-biotin) p53 DNA molecule onto a gold substrate via gold-thiol chemistry, whilst the biotinylated 3' end is available for 'pick-up' using a streptavidin modified AFM tip. We also show that co-surface immobilization of DNA with 6-mercapto-1-hexanol (MCH) can also lead to a further increase the measured contour length. We demonstrate the impact of these improved protocols through the observation of the cooperative transition plateau in a DNA fragment of approximately 118 bp, a significantly smaller fragment than previously investigated. The results of a comparative study of the effects of a model minor groove binder (Hoechst 33258) and an intercalating drug (proflavine), alone, as a mixture and under different buffer conditions, are also presented.

Evaluating Red Reflex and Surgeon Preference Between Nearly-Collimated and Focused Beam Microscope Illumination Systems.

PubMed

Cionni, Robert J; Pei, Ron; Dimalanta, Ramon; Lubeck, David

2015-08-01

To evaluate the intensity and stability of the red reflex produced by ophthalmic surgical microscopes with nearly-collimated versus focused illumination systems and to assess surgeon preference in a simulated surgical setting. This two-part evaluation consisted of postproduction surgical video analysis of red reflex intensity and a microscope use and preference survey completed by 13 experienced cataract surgeons. Survey responses were based on bench testing and experience in a simulated surgical setting. A microscope with nearly-collimated beam illumination and two focused beam microscopes were assessed. Red reflex intensity and stability were greater with the nearly-collimated microscope illumination system. In the bench testing survey, surgeons reported that the red reflex was maintained over significantly greater distances away from pupillary center, and depth of focus was numerically greater with nearly-collimated illumination relative to focused illumination. Most participating surgeons (≥64%) reported a preference for the microscope with nearly-collimated illumination with regard to red reflex stability, depth of focus, visualization, surgical working distance, and perceived patient comfort. The microscope with nearly-collimated illumination produced a more intense and significantly more stable red reflex and was preferred overall by more surgeons. This is the first report of an attempt to quantify red reflex intensity and stability and to evaluate surgically-relevant parameters between microscope systems. The data and methods presented here may provide a basis for future studies attempting to quantify differences between surgical microscopes that may affect surgeon preference and microscope use in ophthalmic surgery.

An open source, wireless capable miniature microscope system

NASA Astrophysics Data System (ADS)

Liberti, William A., III; Perkins, L. Nathan; Leman, Daniel P.; Gardner, Timothy J.

2017-08-01

Objective. Fluorescence imaging through head-mounted microscopes in freely behaving animals is becoming a standard method to study neural circuit function. Flexible, open-source designs are needed to spur evolution of the method. Approach. We describe a miniature microscope for single-photon fluorescence imaging in freely behaving animals. The device is made from 3D printed parts and off-the-shelf components. These microscopes weigh less than 1.8 g, can be configured to image a variety of fluorophores, and can be used wirelessly or in conjunction with active commutators. Microscope control software, based in Swift for macOS, provides low-latency image processing capabilities for closed-loop, or BMI, experiments. Main results. Miniature microscopes were deployed in the songbird premotor region HVC (used as a proper name), in singing zebra finches. Individual neurons yield temporally precise patterns of calcium activity that are consistent over repeated renditions of song. Several cells were tracked over timescales of weeks and months, providing an opportunity to study learning related changes in HVC. Significance. 3D printed miniature microscopes, composed completely of consumer grade components, are a cost-effective, modular option for head-mounting imaging. These easily constructed and customizable tools provide access to cell-type specific neural ensembles over timescales of weeks.

Dynamics of gene expression during development and expansion of vegetative stem internodes of bioenergy sorghum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kebrom, Tesfamichael H.; McKinley, Brian; Mullet, John E.

Bioenergy sorghum accumulates 75% of shoot biomass in stem internodes. Grass stem internodes are formed during vegetative growth and elongate in response to developmental and environmental signals. To identify genes and molecular mechanisms that modulate the extent of internode growth, we conducted microscopic and transcriptomic analyses of four successive sub-apical vegetative internodes representing different stages of internode development of the bioenergy sorghum genotype R.07020. Stem internodes of sorghum genotype R.07020 are formed during the vegetative phase and their length is enhanced by environmental signals such as shade and floral induction in short days. During vegetative growth, the first visible andmore » youngest sub-apical internode was ~0.7 cm in length, whereas the fourth fully expanded internode was ~5 cm in length. Microscopic analyses revealed that all internode tissue types including pith parenchyma and vascular bundles are present in the four successive internodes. Growth in the first two sub-apical internodes occurred primarily through an increase in cell number consistent with expression of genes involved in the cell cycle and DNA replication. Growth of the 3rd internode was associated with an increase in cell length and growth cessation in the 4th internode was associated with up-regulation of genes involved in secondary cell wall deposition. The expression of genes involved in hormone metabolism and signaling indicates that GA, BR, and CK activity decreased while ethylene, ABA, and JA increased in the 3rd/4th internodes. While the level of auxin appears to be increasing as indicated by the up-regulation of ARFs, down-regulation of TIR during development indicates that auxin signaling is also modified. The expression patterns of transcription factors are closely associated with their role during the development of the vegetative internodes. Microscopic and transcriptome analyses of four successive sub-apical internodes characterized the developmental progression of vegetative stem internodes from initiation through full elongation in the sorghum genotype R.07020. Transcriptome profiling indicates that dynamic variation in the levels and action of GA, CK, IAA, BR, ethylene, ABA, and JA modulate gene expression and growth during internode growth and development. Thus, this study provides detailed microscopic and transcriptomic data useful for identifying genes and molecular pathways regulating internode elongation in response to various developmental and environmental signals.« less

Dynamics of gene expression during development and expansion of vegetative stem internodes of bioenergy sorghum

DOE PAGES

Kebrom, Tesfamichael H.; McKinley, Brian; Mullet, John E.

2017-06-21

Bioenergy sorghum accumulates 75% of shoot biomass in stem internodes. Grass stem internodes are formed during vegetative growth and elongate in response to developmental and environmental signals. To identify genes and molecular mechanisms that modulate the extent of internode growth, we conducted microscopic and transcriptomic analyses of four successive sub-apical vegetative internodes representing different stages of internode development of the bioenergy sorghum genotype R.07020. Stem internodes of sorghum genotype R.07020 are formed during the vegetative phase and their length is enhanced by environmental signals such as shade and floral induction in short days. During vegetative growth, the first visible andmore » youngest sub-apical internode was ~0.7 cm in length, whereas the fourth fully expanded internode was ~5 cm in length. Microscopic analyses revealed that all internode tissue types including pith parenchyma and vascular bundles are present in the four successive internodes. Growth in the first two sub-apical internodes occurred primarily through an increase in cell number consistent with expression of genes involved in the cell cycle and DNA replication. Growth of the 3rd internode was associated with an increase in cell length and growth cessation in the 4th internode was associated with up-regulation of genes involved in secondary cell wall deposition. The expression of genes involved in hormone metabolism and signaling indicates that GA, BR, and CK activity decreased while ethylene, ABA, and JA increased in the 3rd/4th internodes. While the level of auxin appears to be increasing as indicated by the up-regulation of ARFs, down-regulation of TIR during development indicates that auxin signaling is also modified. The expression patterns of transcription factors are closely associated with their role during the development of the vegetative internodes. Microscopic and transcriptome analyses of four successive sub-apical internodes characterized the developmental progression of vegetative stem internodes from initiation through full elongation in the sorghum genotype R.07020. Transcriptome profiling indicates that dynamic variation in the levels and action of GA, CK, IAA, BR, ethylene, ABA, and JA modulate gene expression and growth during internode growth and development. Thus, this study provides detailed microscopic and transcriptomic data useful for identifying genes and molecular pathways regulating internode elongation in response to various developmental and environmental signals.« less

Chronic Traumatic Encephalopathy in Athletes: Progressive Tauopathy following Repetitive Head Injury

PubMed Central

McKee, Ann C.; Cantu, Robert C.; Nowinski, Christopher J.; Hedley-Whyte, E. Tessa; Gavett, Brandon E.; Budson, Andrew E.; Santini, Veronica E.; Lee, Hyo-Soon; Kubilus, Caroline A.; Stern, Robert A.

2009-01-01

Since the 1920s, it has been known that the repetitive brain trauma associated with boxing may produce a progressive neurological deterioration, originally termed “dementia pugilistica” and more recently, chronic traumatic encephalopathy (CTE). We review the 47 cases of neuropathologically verified CTE recorded in the literature and document the detailed findings of CTE in 3 professional athletes: one football player and 2 boxers. Clinically, CTE is associated with memory disturbances, behavioral and personality changes, Parkinsonism, and speech and gait abnormalities. Neuropathologically, CTE is characterized by atrophy of the cerebral hemispheres, medial temporal lobe, thalamus, mammillary bodies, and brainstem, with ventricular dilatation and a fenestrated cavum septum pellucidum. Microscopically, there are extensive tau-immunoreactive neurofibrillary tangles, astrocytic tangles, and spindle-shaped and threadlike neurites throughout the brain. The neurofibrillary degeneration of CTE is distinguished from other tauopathies by preferential involvement of the superficial cortical layers, irregular, patchy distribution in the frontal and temporal cortices, propensity for sulcal depths, prominent perivascular, periventricular and subpial distribution, and marked accumulation of tau-immunoreactive astrocytes. Deposition of beta amyloid, most commonly as diffuse plaques, occurs in fewer than half the cases. CTE is a neuropathologically distinct, slowly progressive tauopathy with a clear environmental etiology. PMID:19535999

Development of an ultrasound microscope combined with optical microscope for multiparametric characterization of a single cell.

PubMed

Arakawa, Mototaka; Shikama, Joe; Yoshida, Koki; Nagaoka, Ryo; Kobayashi, Kazuto; Saijo, Yoshifumi

2015-09-01

Biomechanics of the cell has been gathering much attention because it affects the pathological status in atherosclerosis and cancer. In the present study, an ultrasound microscope system combined with optical microscope for characterization of a single cell with multiple ultrasound parameters was developed. The central frequency of the transducer was 375 MHz and the scan area was 80 × 80 μm with up to 200 × 200 sampling points. An inverted optical microscope was incorporated in the design of the system, allowing for simultaneous optical observations of cultured cells. Two-dimensional mapping of multiple ultrasound parameters, such as sound speed, attenuation, and acoustic impedance, as well as the thickness, density, and bulk modulus of specimen/cell under investigation, etc., was realized by the system. Sound speed and thickness of a 3T3-L1 fibroblast cell were successfully obtained by the system. The ultrasound microscope system combined with optical microscope further enhances our understanding of cellular biomechanics.

Correlated light and electron microscopy observations of the uterine epithelial cell actin cytoskeleton using fluorescently labeled resin-embedded sections.

PubMed

Moore, Chad L; Cheng, Delfine; Shami, Gerald J; Murphy, Christopher R

2016-05-01

In order to perform correlative light and electron microscopy (CLEM) more precisely, we have modified existing specimen preparation protocols allowing fluorescence retention within embedded and sectioned tissue, facilitating direct observation across length scales. We detail a protocol which provides a precise correlation accuracy using accessible techniques in biological specimen preparation. By combining a pre-embedding uranyl acetate staining step with the progressive lowering of temperature (PLT) technique, a methacrylate embedded tissue specimen is ultrathin sectioned and mounted onto a TEM finder grid for immediate viewing in the confocal and electron microscope. In this study, the protocol is applied to rat uterine epithelial cells in vivo during early pregnancy. Correlative overlay data was used to track changes in filamentous actin that occurs in these cells from fertilization (Day 1) to implantation on Day 6 as part of the plasma membrane transformation, a process essential in the development of uterine receptivity in the rat. CLEM confirmed that the actin cytoskeleton is disrupted as apical microvilli are progressively lost toward implantation, and revealed the thick and continuous terminal web is replaced by a thinner and irregular actin band, with individually distinguishable filaments connecting actin meshworks which correspond with remaining plasma membrane protrusions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Canine degenerative myelopathy: a model of human amyotrophic lateral sclerosis.

PubMed

Nardone, Raffaele; Höller, Yvonne; Taylor, Alexandra C; Lochner, Piergiorgio; Tezzon, Frediano; Golaszewski, Stefan; Brigo, Francesco; Trinka, Eugen

2016-02-01

Canine degenerative myelopathy (CDM) represents a unique naturally occurring animal model for human amyotrophic lateral sclerosis (ALS) because of similar clinical signs, neuropathologic findings, and involvement of the superoxide dismutase 1 (SOD1) mutation. A definitive diagnosis can only be made postmortem through microscopic detection of axonal degeneration, demyelination and astroglial proliferation, which is more severe in the dorsal columns of the thoracic spinal cord and in the dorsal portion of the lateral funiculus. Interestingly, the muscle acetylcholine receptor complexes are intact in CDM prior to functional impairment, thus suggesting that muscle atrophy in CDM does not result from physical denervation. Moreover, since sensory involvement seems to play an important role in CDM progression, a more careful investigation of the sensory pathology in ALS is also warranted. The importance of SOD1 expression remains unclear, while oxidative stress and denatured ubiquinated proteins appear to play a crucial role in the pathogenesis of CDM. In this updated narrative review we performed a systematic search of the published studies on CDM that may shed light on the pathophysiological mechanisms of human ALS. A better understanding of the factors that determine the disease progression in CDM may be beneficial for the development of effective treatments for ALS. Copyright © 2015 Elsevier GmbH. All rights reserved.

QLF monitoring of therapies for early secondary caries arrestment and remineralization

NASA Astrophysics Data System (ADS)

Fontana, Margherita; Gonzalez-Cabezas, Carlos; Stookey, George K.

2000-03-01

Secondary caries (SC) is the most common reason for restoration failure. The purpose of this study was to evaluate the Quantitative Light-Induced Fluorescence (QLF) method for monitoring therapies to inhibit SC progression. Forty-eight human teeth with resin restorations were demineralized for 4 days in a microbial caries model. Half of each specimen was then covered with an acid-resistant varnish to maintain the baseline lesion, and treated (group 1: non-treated control; group 2: chlorhexidine varnish for 24 h; group 3: fluoride varnish for 24 h; group 4: APF topical fluoride gel for 4 min), prior to being demineralized for 4 more days. Specimens were analyzed by QLF, sectioned, stained with Rhodamine B, and analyzed with a confocal microscope (CLSM) for lesion depth. The QLF results indicated that the control group was significantly (p less than 0.05) different (i.e., lesions progressed) from groups treated with fluoride (groups 3 and 4; lesions remineralized). All other group comparisons were not significantly different. Results obtained from CLSM analysis were similar to the ones obtained with QLF, except that lesions in group 2 were significantly deeper than the ones in the fluoride groups. Results suggest that the QLF method has a clear potential for monitoring remineralizing therapies for SC.

Power-Laws and Scaling in Finance: Empirical Evidence and Simple Models

NASA Astrophysics Data System (ADS)

Bouchaud, Jean-Philippe

We discuss several models that may explain the origin of power-law distributions and power-law correlations in financial time series. From an empirical point of view, the exponents describing the tails of the price increments distribution and the decay of the volatility correlations are rather robust and suggest universality. However, many of the models that appear naturally (for example, to account for the distribution of wealth) contain some multiplicative noise, which generically leads to non universal exponents. Recent progress in the empirical study of the volatility suggests that the volatility results from some sort of multiplicative cascade. A convincing `microscopic' (i.e. trader based) model that explains this observation is however not yet available. We discuss a rather generic mechanism for long-ranged volatility correlations based on the idea that agents constantly switch between active and inactive strategies depending on their relative performance.

A systematic optimization for graphene-based supercapacitors

NASA Astrophysics Data System (ADS)

Deuk Lee, Sung; Lee, Han Sung; Kim, Jin Young; Jeong, Jaesik; Kahng, Yung Ho

2017-08-01

Increasing the energy-storage density for supercapacitors is critical for their applications. Many researchers have attempted to identify optimal candidate component materials to achieve this goal, but investigations into systematically optimizing their mixing rate for maximizing the performance of each candidate material have been insufficient, which hinders the progress in their technology. In this study, we employ a statistically systematic method to determine the optimum mixing ratio of three components that constitute graphene-based supercapacitor electrodes: reduced graphene oxide (rGO), acetylene black (AB), and polyvinylidene fluoride (PVDF). By using the extreme-vertices design, the optimized proportion is determined to be (rGO: AB: PVDF  =  0.95: 0.00: 0.05). The corresponding energy-storage density increases by a factor of 2 compared with that of non-optimized electrodes. Electrochemical and microscopic analyses are performed to determine the reason for the performance improvements.

Rolling Shutter Effect aberration compensation in Digital Holographic Microscopy

NASA Astrophysics Data System (ADS)

Monaldi, Andrea C.; Romero, Gladis G.; Cabrera, Carlos M.; Blanc, Adriana V.; Alanís, Elvio E.

2016-05-01

Due to the sequential-readout nature of most CMOS sensors, each row of the sensor array is exposed at a different time, resulting in the so-called rolling shutter effect that induces geometric distortion to the image if the video camera or the object moves during image acquisition. Particularly in digital holograms recording, while the sensor captures progressively each row of the hologram, interferometric fringes can oscillate due to external vibrations and/or noises even when the object under study remains motionless. The sensor records each hologram row in different instants of these disturbances. As a final effect, phase information is corrupted, distorting the reconstructed holograms quality. We present a fast and simple method for compensating this effect based on image processing tools. The method is exemplified by holograms of microscopic biological static objects. Results encourage incorporating CMOS sensors over CCD in Digital Holographic Microscopy due to a better resolution and less expensive benefits.

Adaptive characterization of recrystallization kinetics in IF steel by electron backscatter diffraction.

PubMed

Kim, Dong-Kyu; Park, Won-Woong; Lee, Ho Won; Kang, Seong-Hoon; Im, Yong-Taek

2013-12-01

In this study, a rigorous methodology for quantifying recrystallization kinetics by electron backscatter diffraction is proposed in order to reduce errors associated with the operator's skill. An adaptive criterion to determine adjustable grain orientation spread depending on the recrystallization stage is proposed to better identify the recrystallized grains in the partially recrystallized microstructure. The proposed method was applied in characterizing the microstructure evolution during annealing of interstitial-free steel cold rolled to low and high true strain levels of 0.7 and 1.6, respectively. The recrystallization kinetics determined by the proposed method was found to be consistent with the standard method of Vickers microhardness. The application of the proposed method to the overall recrystallization stages showed that it can be used for the rigorous characterization of progressive microstructure evolution, especially for the severely deformed material. © 2013 The Authors Journal of Microscopy © 2013 Royal Microscopical Society.

Microautophagy in nutritive phagocytes of sea urchins.

PubMed

Kalachev, Alexander V; Yurchenko, Olga V

2017-01-01

Two types of cells were observed in germinative epithelium of male and female sea urchins: germ cells and somatic accessory cells; the latter referred to as nutritive phagocytes. At the onset of gametogenesis, nutritive phagocytes accumulate nutrients and greatly increase in their size. As gametogenesis progresses, the accumulated nutrients are transferred from nutritive phagocytes into developing gametes, and size of the nutritive phagocytes decreases. An electron microscopic study of nutritive phagocytes in sea urchins, Strongylocentrotus intermedius, at different stages of annual reproductive cycle showed for the first time that both macro- and microautophagy take place in nutritive phagocytes. Both processes occur simultaneously and regulate size and composition of nutritive phagocytes in male and female sea urchins. Nutritive phagocytes consume redundant cytoplasm via macroautophagy. Microautophagy is probably involved in consumption of redundant membranes that appear within nutritive phagocytes due to destruction of nutrient-storing globules, macroautophagy, and phagocytosis of germ cells or their remnants.

Supramolecular Systems and Chemical Reactions in Single-Molecule Break Junctions.

PubMed

Li, Xiaohui; Hu, Duan; Tan, Zhibing; Bai, Jie; Xiao, Zongyuan; Yang, Yang; Shi, Jia; Hong, Wenjing

2017-04-01

The major challenges of molecular electronics are the understanding and manipulation of the electron transport through the single-molecule junction. With the single-molecule break junction techniques, including scanning tunneling microscope break junction technique and mechanically controllable break junction technique, the charge transport through various single-molecule and supramolecular junctions has been studied during the dynamic fabrication and continuous characterization of molecular junctions. This review starts from the charge transport characterization of supramolecular junctions through a variety of noncovalent interactions, such as hydrogen bond, π-π interaction, and electrostatic force. We further review the recent progress in constructing highly conductive molecular junctions via chemical reactions, the response of molecular junctions to external stimuli, as well as the application of break junction techniques in controlling and monitoring chemical reactions in situ. We suggest that beyond the measurement of single molecular conductance, the single-molecule break junction techniques provide a promising access to study molecular assembly and chemical reactions at the single-molecule scale.

THREE-DIMENSIONAL RANDOM ACCESS MULTIPHOTON MICROSCOPY FOR FAST FUNCTIONAL IMAGING OF NEURONAL ACTIVITY

PubMed Central

Reddy, Gaddum Duemani; Kelleher, Keith; Fink, Rudy; Saggau, Peter

2009-01-01

The dynamic ability of neuronal dendrites to shape and integrate synaptic responses is the hallmark of information processing in the brain. Effectively studying this phenomenon requires concurrent measurements at multiple sites on live neurons. Significant progress has been made by optical imaging systems which combine confocal and multiphoton microscopy with inertia-free laser scanning. However, all systems developed to date restrict fast imaging to two dimensions. This severely limits the extent to which neurons can be studied, since they represent complex three-dimensional (3D) structures. Here we present a novel imaging system that utilizes a unique arrangement of acousto-optic deflectors to steer a focused ultra-fast laser beam to arbitrary locations in 3D space without moving the objective lens. As we demonstrate, this highly versatile random-access multiphoton microscope supports functional imaging of complex 3D cellular structures such as neuronal dendrites or neural populations at acquisition rates on the order of tens of kilohertz. PMID:18432198

Chemical compatibility of cartridge materials

NASA Technical Reports Server (NTRS)

Wilcox, Roy C.; Zee, R. H.

1991-01-01

This twelve month progress report deals with the chemical compatibility of semiconductor crystals grown in zero gravity. Specifically, it studies the chemical compatibility between TZM, a molybdenum alloy containing titanium and zirconium, and WC 103, a titanium alloy containing Niobium and Hafnium, and Gallium arsenide (GaAs) and Cadmium Zinc Tellurite (CdZnTe). Due to the health hazards involved, three approaches were used to study the chemical compatibility between the semiconductor and cartridge materials: reaction retort, thermogravimetric analysis, and bulk cylindrical cartridge containers. A scanning electron microscope with an energy dispersive X-ray analyzer was used to examine all samples after testing. The first conclusion drawn is that reaction rates with TZM were not nearly as great as they were with WC 103. Second, the total reaction between GaAs and WC 103 was almost twice that with TZM. Therefore, even though WC 103 is easier to fabricate, at least half of the cartridge thickness will be degraded if contact is made with one of the semiconductor materials leading to a loss of strength properties.

Size determination of Acipenser ruthenus spermatozoa in different types of electron microscopy.

PubMed

Psenicka, Martin; Tesarová, Martina; Tesitel, Jakub; Nebesárová, Jana

2010-07-01

In this study three types of scanning electron microscopes were used for the size determination of spermatozoa of sterlet Acipenser ruthenus - high vacuum scanning electron microscope (SEM, JEOL 6300), environmental scanning electron microscope (ESEM, Quanta 200 FEG), field emission scanning electron microscope (FESEM, JEOL 7401F) with cryoattachment Alto 2500 (Gatan) and transmission electron microscope (TEM, JEOL 1010). The use of particular microscopes was tied with different specimen preparation techniques. The aim of this study was to evaluate to what degree the type of used electron microscope can influence the size of different parts of spermatozoa. For high vacuum SEM the specimen was prepared using two slightly different procedures. After chemical fixation with 2.5% glutaraldehyde in 0.1M phosphate buffer and post-fixation by 1% osmium tetroxide, the specimen was dehydrated by acetone series and dried either by critical point method or by means of t-butylalcohol. For ESEM fresh, unfixed material was used, which was dropped on microscopic copper grids. In FESEM working in cryo-mode the specimen was observed in a frozen state. Ultrathin sections from chemically fixed and Epon embedded specimens were prepared for TEM observation. Distinct parts of sterlet spermatozoa were measured in each microscope and the data obtained was statistically processed. Results confirmed that the classical chemical procedure of specimen preparation for SEM including critical point drying method led to a significant contraction of all measured values, which could deviate up to 30% in comparison with values measured on the fresh chemically untreated specimen in ESEM. Surprisingly sperm dimensions determinated on ultrathin sections by TEM are comparable with values obtained in ESEM or FESEM. Copyright 2010 Elsevier Ltd. All rights reserved.

Diagenetic effects on magnetic minerals in a Holocene lacustrine sediment core from Huguangyan maar lake, southeast China

NASA Astrophysics Data System (ADS)

Wu, Xudong; Wang, Yong; Bian, Liu; Shen, Ji

2016-09-01

Post-depositional reductive diagenesis usually results in partial or entire cleansing of the pristine palaeomagnetic signal, therefore, its intensity is important to be assessed for sediments that are in the purpose of retrieving palaeomagnetic information. Grain size, rock magnetic and geochemical studies on the entire core, along with scanning electron microscope observations and X-ray diffraction analyses for representative samples were carried out on a Holocene sediment core retrieved from the deep water part of Huguangyan maar lake (HGY), southeast China. The pristine magnetic mineral assemblage of the studied core is domianted by superparamagnetic (SP) and stable single domain titanomagnetite, and high coercivity minerals are not detectable. Based on down-core variations of the average grain size (MZ), total organic carbon (TOC), detrital elements (Al, Ti, Fe and Mn) and the concentration and mineralogy of magnetic minerals, the studied core could be divided into three subsections. The uppermost subsection is the least affected by diagenesis, with detrital titanomagnetite as the dominant magnetic mineral. This is owing to low TOC contents, but high detrital input generated by weak Asian summer monsoon intensity during the late Holocene. The intermediate subsection shows down-core progressively enhanced dissolution of detrital titanomagnetite, and concomitant formation of authigenic pyrite and siderite, which indicates down-core progressively enhanced diagenesis generated by down-core progressive increasing TOC content, but decreasing detrital input as the result of down-core progressively strengthened Asian summer monsoon intensity. The pristine magnetic mineral assemblage has been profoundly modified in the lowermost subsection. At certain positions of the lowermost subsection, detrital titanomagnetite has been even completely dissolved via diagenesis, giving place to authigenic pyrite and siderite. High TOC content, but low detrital input generated from strong Asian summer monsoon intensity during the early Holocene are accountable for intensive diagenesis in the lowermost subsection. Complete erasing of detrital magnetic input signal at certain positions of the lowermost subsection, and considerable formation of authigenic siderite indicate that palaeomagnetic records of the studied core have been significantly compromised. The studied core has relatively higher TOC content, lower detrital matter content, calmer sedimentary environments, and less DO available at its water-sediment interface than the cores retrieved at relatively shallower water depths, which all contribute to its relatively stronger diagenesis. Progressive thickening of the upper two subsections with increasing water depth is owing to progressive increase in sedimentation rate with increasing water depth, which is the key factor in determining the thickness of each diagenetic subsection of cores from HGY. It would be better that lake sediments for palaeomagnetic investigations collected at a water depth shallower than the depth of its thermocline.

Progressive hearing loss and degeneration of hair cell stereocilia in taperin gene knockout mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Mo; Wang, Qin; Zhu, Gang-Hua

The TPRN gene encodes taperin, which is prominently present at the taper region of hair cell stereocilia. Mutations in TPRN have been reported to cause autosomal recessive nonsyndromic deafness 79(DFNB 79). To investigate the role of taperin in pathogenesis of hearing loss, we generated TPRN knockout mice using TALEN technique. Sanger sequencing confirmed an 11 bp deletion at nucleotide 177–187 in exon 1 of TPRN, which results in a truncated form of taperin protein. Heterozygous TPRN{sup +/−} mice showed apparently normal auditory phenotypes to their wide-type (WT) littermates. Homozygous TPRN{sup −/−} mice exhibited progressive sensorineural hearing loss as reflected bymore » auditory brainstem response to both click and tone burst stimuli at postnatal days 15 (P15), 30 (P30), and 60 (P60). Alex Fluor-594 phalloidin labeling showed no obvious difference in hair cell numbers in the cochlea between TPRN{sup −/−} mice and WT mice under light microscope. However, scanning electronic microscopy revealed progressive degeneration of inner hair cell stereocilia, from apparently normal at postnatal days 3 (P3) to scattered absence at P15 and further to substantial loss at P30. The outer hair cell stereocilia also showed progressive degeneration, though much less severe, Collectively, we conclude that taperin plays an important role in maintenance of hair cell stereocilia. Establishment of TPRN knockout mice enables further investigation into the function of this gene. - Highlights: • TPRN{sup −/−} mice were generated using TALEN technique. • TPRN{sup −/−} mice presented progressive hearing loss. • WT and TPRN{sup −/−} mice showed no difference in hair cell numbers. • TPRN{sup −/−} mice showed progressive degeneration of hair cell stereocilia.« less

Atomic force microscopic study of the influence of physical stresses on Saccharomyces cerevisiae and Schizosaccharomyces pombe.

PubMed

Adya, Ashok K; Canetta, Elisabetta; Walker, Graeme M

2006-01-01

Morphological changes in the cell surfaces of the budding yeast Saccharomyces cerevisiae (strain NCYC 1681), and the fission yeast Schizosaccharomyces pombe (strain DVPB 1354), in response to thermal and osmotic stresses, were investigated using an atomic force microscope. With this microscope imaging, together with measurements of culture viability and cell size, it was possible to relate topological changes of the cell surface at nanoscale with cellular stress physiology. As expected, when the yeasts were exposed to thermostress or osmostress, their viability together with the mean cell volume decreased in conjunction with the increase in thermal or osmotic shock. Nevertheless, the viability of cells stressed for up to 1 h remained relatively high. For example, viabilities were >50% and >90% for the thermostressed, and >60% and >70% for the osmostressed S. cerevisiae and Schiz. pombe, respectively. Mean cell volume measurements, and bearing and roughness analyses of atomic force microscope images of stressed yeasts indicate that Schiz. pombe may be more resistant to physical stresses than S. cerevisiae. Overall, this study has highlighted the usefulness of atomic force microscope in studies of yeast stress physiology.

Frequency of second mesiobuccal canal in permanent maxillary first molars using the operating microscope and selective dentin removal: A clinical study.

PubMed

Das, Suroopa; Warhadpande, Manjusha M; Redij, Saurabh A; Jibhkate, N G; Sabir, Husain

2015-01-01

The aim of this study was to investigate whether the combination of operating microscope and selective dentin removal increased the frequency of second mesiobuccal (MB2) canal detection in permanent maxillary first molar teeth. One hundred fifty permanent maxillary first molars indicated for root canal treatment were randomly selected from patients belonging to the age group of 18-45 years irrespective of gender. After access cavity preparation and location of main canals, the MB2 canal orifice was sought in all teeth with an endodontic explorer under direct vision (Stage I), then under magnification with the aid of operating microscope (Stage II) and finally with the combined use of operating microscope and selective dentin removal (Stage III). MB2 canals were detected in 36%, 54% and 72% of the teeth in Stages I-III, respectively. This study demonstrated that dental operating microscope when used along with adjunctive aids such as selective dentin removal/troughing and good clinical knowledge will increase the ability of dental clinician to locate MB2 canals.

Orchiectomy for suspected microscopic tumor in patients with anti-Ma2-associated encephalitis.

PubMed

Mathew, R M; Vandenberghe, R; Garcia-Merino, A; Yamamoto, T; Landolfi, J C; Rosenfeld, M R; Rossi, J E; Thiessen, B; Dropcho, E J; Dalmau, J

2007-03-20

To report the presence of microscopic neoplasms of the testis in men with anti-Ma2-associated encephalitis (Ma2-encephalitis) and to discuss the clinical implications. Orchiectomy specimens were examined using immunohistochemistry with Ma2 and Oct4 antibodies. Among 25 patients with Ma2-encephalitis younger than 50 years, 19 had germ-cell tumors, and 6 had no evidence of cancer. These 6 patients underwent orchiectomy because they fulfilled five criteria: 1) demonstration of anti-Ma2 antibodies in association with MRI or clinical features compatible with Ma2-encephalitis, 2) life-threatening or progressive neurologic deficits, 3) age < 50 years, 4) absence of other tumors, and 5) new testicular enlargement or risk factors for germ-cell tumors, mainly cryptorchidism or ultrasound evidence of testicular microcalcifications. All orchiectomy specimens showed intratubular-germ cell neoplasms unclassified type (IGCNU) and other abnormalities including microcalcifications, atrophy, fibrosis, inflammatory infiltrates, or hypospermatogenesis. Ma2 was expressed by neoplastic cells in three of three patients examined. Even though most patients had severe neurologic deficits at the time of orchiectomy (median progression of symptoms, 10 months), 4 had partial improvement and prolonged stabilization (8 to 84 months, median 22.5 months) and two did not improve after the procedure. In young men with Ma2-encephalitis, 1) the disorder should be attributed to a germ-cell neoplasm of the testis unless another Ma2-expressing tumor is found, 2) negative tumor markers, ultrasound, body CT, or PET do not exclude an intratubular germ-cell neoplasm of the testis, and 3) if no tumor is found, the presence of the five indicated criteria should prompt consideration of orchiectomy.

Orchiectomy for suspected microscopic tumor in patients with anti-Ma2-associated encephalitis

PubMed Central

Mathew, R.M.; Vandenberghe, R.; Garcia-Merino, A.; Yamamoto, T.; Landolfi, J.C.; Rosenfeld, M.R.; Rossi, J.E.; Thiessen, B.; Dropcho, E.J.; Dalmau, J.

2007-01-01

Objective: To report the presence of microscopic neoplasms of the testis in men with anti-Ma2-associated encephalitis (Ma2-encephalitis) and to discuss the clinical implications. Methods: Orchiectomy specimens were examined using immunohistochemistry with Ma2 and Oct4 antibodies. Results: Among 25 patients with Ma2-encephalitis younger than 50 years, 19 had germ-cell tumors, and 6 had no evidence of cancer. These 6 patients underwent orchiectomy because they fulfilled five criteria: 1) demonstration of anti-Ma2 antibodies in association with MRI or clinical features compatible with Ma2-encephalitis, 2) life-threatening or progressive neurologic deficits, 3) age < 50 years, 4) absence of other tumors, and 5) new testicular enlargement or risk factors for germ-cell tumors, mainly cryptorchidism or ultrasound evidence of testicular microcalcifications. All orchiectomy specimens showed intratubular-germ cell neoplasms unclassified type (IGCNU) and other abnormalities including microcalcifications, atrophy, fibrosis, inflammatory infiltrates, or hypospermatogenesis. Ma2 was expressed by neoplastic cells in three of three patients examined. Even though most patients had severe neurologic deficits at the time of orchiectomy (median progression of symptoms, 10 months), 4 had partial improvement and prolonged stabilization (8 to 84 months, median 22.5 months) and two did not improve after the procedure. Conclusions: In young men with Ma2-encephalitis, 1) the disorder should be attributed to a germ-cell neoplasm of the testis unless another Ma2-expressing tumor is found, 2) negative tumor markers, ultrasound, body CT, or PET do not exclude an intratubular germ-cell neoplasm of the testis, and 3) if no tumor is found, the presence of the five indicated criteria should prompt consideration of orchiectomy. PMID:17151337

Development of a novel pink-eyed dilution mouse model showing progressive darkening of the eyes and coat hair with aging

PubMed Central

ISHIKAWA, Akira; SUGIYAMA, Makoto; HONDO, Eiichi; KINOSHITA, Keiji; YAMAGISHI, Yuki

2015-01-01

Oca2p-cas (oculocutaneous albinism II; pink-eyed dilution castaneus) is a coat color mutant gene on mouse chromosome 7 that arose spontaneously in wild Mus musculus castaneus mice. Mice homozygous for Oca2p-cas usually exhibit pink eyes and gray coat hair on the non-agouti genetic background, and this ordinary phenotype remains unchanged throughout life. During breeding of a mixed strain carrying this gene on the C57BL/6J background, we discovered a novel spontaneous mutation that causes darkening of the eyes and coat hair with aging. In this study, we developed a novel mouse model showing this unique phenotype. Gross observations revealed that the pink eyes and gray coat hair of the novel mutant young mice became progressively darker in color by approximately 3 months after birth. Light and transmission-electron microscopic observations revealed a marked increase in melanin pigmentation of coat hair shafts and choroid of the eye in the novel mice compared to that in the ordinary mice. Sequence analysis of Oca2p-cas revealed a 4.1-kb deletion involving exons 15 and 16 of its wild-type gene. However, there was no sequence difference between the two types of mutant mice. Mating experiments suggested that the novel mutant phenotype was not inherited in a simple fashion, due to incomplete penetrance. The novel spontaneous mutant mouse is the first example of progressive hair darkening animals and is an essential animal model for understanding of the regulation mechanisms of melanin biosynthesis with aging. PMID:25739360

Development of a novel pink-eyed dilution mouse model showing progressive darkening of the eyes and coat hair with aging.

PubMed

Ishikawa, Akira; Sugiyama, Makoto; Hondo, Eiichi; Kinoshita, Keiji; Yamagishi, Yuki

2015-01-01

Oca2(p-cas) (oculocutaneous albinism II; pink-eyed dilution castaneus) is a coat color mutant gene on mouse chromosome 7 that arose spontaneously in wild Mus musculus castaneus mice. Mice homozygous for Oca2(p-cas) usually exhibit pink eyes and gray coat hair on the non-agouti genetic background, and this ordinary phenotype remains unchanged throughout life. During breeding of a mixed strain carrying this gene on the C57BL/6J background, we discovered a novel spontaneous mutation that causes darkening of the eyes and coat hair with aging. In this study, we developed a novel mouse model showing this unique phenotype. Gross observations revealed that the pink eyes and gray coat hair of the novel mutant young mice became progressively darker in color by approximately 3 months after birth. Light and transmission-electron microscopic observations revealed a marked increase in melanin pigmentation of coat hair shafts and choroid of the eye in the novel mice compared to that in the ordinary mice. Sequence analysis of Oca2(p-cas) revealed a 4.1-kb deletion involving exons 15 and 16 of its wild-type gene. However, there was no sequence difference between the two types of mutant mice. Mating experiments suggested that the novel mutant phenotype was not inherited in a simple fashion, due to incomplete penetrance. The novel spontaneous mutant mouse is the first example of progressive hair darkening animals and is an essential animal model for understanding of the regulation mechanisms of melanin biosynthesis with aging.

Evaluating Red Reflex and Surgeon Preference Between Nearly-Collimated and Focused Beam Microscope Illumination Systems

PubMed Central

Cionni, Robert J.; Pei, Ron; Dimalanta, Ramon; Lubeck, David

2015-01-01

Purpose To evaluate the intensity and stability of the red reflex produced by ophthalmic surgical microscopes with nearly-collimated versus focused illumination systems and to assess surgeon preference in a simulated surgical setting. Methods This two-part evaluation consisted of postproduction surgical video analysis of red reflex intensity and a microscope use and preference survey completed by 13 experienced cataract surgeons. Survey responses were based on bench testing and experience in a simulated surgical setting. A microscope with nearly-collimated beam illumination and two focused beam microscopes were assessed. Results Red reflex intensity and stability were greater with the nearly-collimated microscope illumination system. In the bench testing survey, surgeons reported that the red reflex was maintained over significantly greater distances away from pupillary center, and depth of focus was numerically greater with nearly-collimated illumination relative to focused illumination. Most participating surgeons (≥64%) reported a preference for the microscope with nearly-collimated illumination with regard to red reflex stability, depth of focus, visualization, surgical working distance, and perceived patient comfort. Conclusions The microscope with nearly-collimated illumination produced a more intense and significantly more stable red reflex and was preferred overall by more surgeons. Translational Relevance This is the first report of an attempt to quantify red reflex intensity and stability and to evaluate surgically-relevant parameters between microscope systems. The data and methods presented here may provide a basis for future studies attempting to quantify differences between surgical microscopes that may affect surgeon preference and microscope use in ophthalmic surgery. PMID:26290778

Panning artifacts in digital pathology images

NASA Astrophysics Data System (ADS)

Avanaki, Ali R. N.; Lanciault, Christian; Espig, Kathryn S.; Xthona, Albert; Kimpe, Tom R. L.

2017-03-01

In making a pathologic diagnosis, a pathologist uses cognitive processes: perception, attention, memory, and search (Pena and Andrade-Filho, 2009). Typically, this involves focus while panning from one region of a slide to another, using either a microscope in a traditional workflow or software program and display in a digital pathology workflow (DICOM Standard Committee, 2010). We theorize that during panning operation, the pathologist receives information important to diagnosis efficiency and/or correctness. As compared to an optical microscope, panning in a digital pathology image involves some visual artifacts due to the following: (i) the frame rate is finite; (ii) time varying visual signals are reconstructed using imperfect zero-order hold. Specifically, after pixel's digital drive is changed, it takes time for a pixel to emit the expected amount of light. Previous work suggests that 49% of navigation is conducted in low-power/overview with digital pathology (Molin et al., 2015), but the influence of display factors has not been measured. We conducted a reader study to establish a relationship between display frame rate, panel response time, and threshold panning speed (above which the artifacts become noticeable). Our results suggest visual tasks that involve tissue structure are more impacted by the simulated panning artifacts than those that only involve color (e.g., staining intensity estimation), and that the panning artifacts versus normalized panning speed has a peak behavior which is surprising and may change for a diagnostic task. This is work in progress and our final findings should be considered in designing future digital pathology systems.

Dynamic full-field infrared imaging with multiple synchrotron beams

PubMed Central

Stavitski, Eli; Smith, Randy J.; Bourassa, Megan W.; Acerbo, Alvin S.; Carr, G. L.; Miller, Lisa M.

2013-01-01

Microspectroscopic imaging in the infrared (IR) spectral region allows for the examination of spatially resolved chemical composition on the microscale. More than a decade ago, it was demonstrated that diffraction limited spatial resolution can be achieved when an apertured, single pixel IR microscope is coupled to the high brightness of a synchrotron light source. Nowadays, many IR microscopes are equipped with multi-pixel Focal Plane Array (FPA) detectors, which dramatically improve data acquisition times for imaging large areas. Recently, progress been made toward efficiently coupling synchrotron IR beamlines to multi-pixel detectors, but they utilize expensive and highly customized optical schemes. Here we demonstrate the development and application of a simple optical configuration that can be implemented on most existing synchrotron IR beamlines in order to achieve full-field IR imaging with diffraction-limited spatial resolution. Specifically, the synchrotron radiation fan is extracted from the bending magnet and split into four beams that are combined on the sample, allowing it to fill a large section of the FPA. With this optical configuration, we are able to oversample an image by more than a factor of two, even at the shortest wavelengths, making image restoration through deconvolution algorithms possible. High chemical sensitivity, rapid acquisition times, and superior signal-to-noise characteristics of the instrument are demonstrated. The unique characteristics of this setup enabled the real time study of heterogeneous chemical dynamics with diffraction-limited spatial resolution for the first time. PMID:23458231

Return-to-play outcomes after microscopic lumbar diskectomy in professional athletes.

PubMed

Watkins, Robert G; Hanna, Robert; Chang, David; Watkins, Robert G

2012-11-01

It has been shown a microscopic lumbar diskectomy (MLD) is effective in getting professional athletes back to their sport after a herniated nucleus pulposus (HNP). There is a need for more information on the time it takes professional athletes to return after surgery. To determine average time for return to play and success in returning to play for professional athletes undergoing MLD. Case series; Level of evidence, 4. Between 1996 and 2010, the senior authors treated 171 professional athletes for lumbar HNP. A retrospective review was performed using patient charts, operative reports, team medical records, and internet search. Eighty-five patients were treated with MLD, and 86 patients were treated nonoperatively. This study focused on the return to play of the operatively treated patients. Primary outcome measures were return rate and average return time, considering only patients whose sport is in season at specific postoperative time points. Of surgically treated patients, 89.3% returned to sport. The average time it took operative patients to return to their sport (return time) was 5.8 months. Progressive return data for surgically treated patients showed the percentage of athletes who returned increased from 50% at 3 months to 72% at 6 months to 77% at 9 months and 84% at 12 months. The chance a player returns to play after MLD is 50% at 3 months, 72% at 6 months, 77% at 9 months, and 84% at 12 months. The overall chance of returning to play at any point is 89%.

Proposal for an in vivo histopathologic scoring system for skin aging by means of confocal microscopy.

PubMed

Longo, Caterina; Casari, Alice; De Pace, Barbara; Simonazzi, Silvia; Mazzaglia, Giovanna; Pellacani, Giovanni

2013-02-01

Many instrumental devices have been testing in analysing and quantifying the skin aging signs. However, histopathology still remains the only methods that allow a microscopic assessment of the skin. However, a skin biopsy is not feasible in aesthetically critical areas such as the face. Recently, confocal microscopy has been discovered as a noninvasive tool with a nearly histologic resolution. Distinct morphologic confocal aspects on facial skin have been described and correlated with the histopathologic counterparts. In our study we aim to develop an easy to use confocal aging score to quantify the skin aging related signs. A sample of facial skin of fifty volunteers has been subjected to confocal imaging. Combining the previously identified confocal features, three different semi-quantitative scores were calculated: - epidermal disarray score (irregular honeycombed pattern + epidermal thickness + furrow pattern); - epidermal hyperplasia score (mottled pigmentation + extent of polycyclic papillary + epidermal thickness; - collagen score (curled fibers, 2 for huddles of collagen, 1 for coarse collagen structures, and 0 for thin reticulated collagen) The epidermal disarray score showed a stable trend up to 65 years and a dramatic increase in the elderly subjects epidermal. Hyperplasia score was characterized by an ascending trend from younger subjects to middle age. The total collagen score showed a progressive trend with age with a different proportion of distinct collagen type. RCM is a powerful, noninvasive technique that could permit to microscopically quantify the aging signs and to test cosmetic efficacy. © 2012 John Wiley & Sons A/S.

Development of a reactive burn model based upon an explicit visco-plastic pore collapse model

NASA Astrophysics Data System (ADS)

Bouton, Eric; Lefrançois, Alexandre; Belmas, Robert

2015-06-01

Our aim in this study is to develop a reactive burn model based upon a microscopic hot spot model to compute the initiation and shock to detonation of pressed TATB explosives. For the sake of simplicity, the hot spots are supposed to result from the viscoplastic collapse of spherical micro-voids inside the composition. Such a model has been incorporated in a lagrangian hydrodynamic code. In our calculations, 8 different pore diameters, ranging from 100 nm to 1.2 μm, have been taken into account and the porosity associated to each pore size has been deduced from the PBX-9502 void distribution derived from the SAXS. The last ingredient of our model is the burn rate that depends on two main variables. The first one is the shock pressure as proposed by the developers of the CREST model. The second one is the number of effective chemical reaction sites calculated by the microscopic model. Furthermore, the function of the reaction progress variable of the burn rate is similar to that in the SURF model proposed by Menikoff. Our burn rate has been calibrated by using pressure profile, material velocities wave forms obtained with embedded particle velocity gauges and run distance to detonation. The comparison between the numerical and experimental results is really good and sufficient to perform a wide variety of simulations including single, double shock waves and the desensitization phenomenon. In conclusion, future works are described.

Miniaturized integration of a fluorescence microscope

PubMed Central

Ghosh, Kunal K.; Burns, Laurie D.; Cocker, Eric D.; Nimmerjahn, Axel; Ziv, Yaniv; Gamal, Abbas El; Schnitzer, Mark J.

2013-01-01

The light microscope is traditionally an instrument of substantial size and expense. Its miniaturized integration would enable many new applications based on mass-producible, tiny microscopes. Key prospective usages include brain imaging in behaving animals towards relating cellular dynamics to animal behavior. Here we introduce a miniature (1.9 g) integrated fluorescence microscope made from mass-producible parts, including semiconductor light source and sensor. This device enables high-speed cellular-level imaging across ∼0.5 mm2 areas in active mice. This capability allowed concurrent tracking of Ca2+ spiking in >200 Purkinje neurons across nine cerebellar microzones. During mouse locomotion, individual microzones exhibited large-scale, synchronized Ca2+ spiking. This is a mesoscopic neural dynamic missed by prior techniques for studying the brain at other length scales. Overall, the integrated microscope is a potentially transformative technology that permits distribution to many animals and enables diverse usages, such as portable diagnostics or microscope arrays for large-scale screens. PMID:21909102

Safety of laser use under the dental microscope.

PubMed

Saegusa, Hidetoshi; Watanabe, Satoshi; Anjo, Tomoo; Ebihara, Arata; Suda, Hideaki

2010-04-01

The aim of this study was to investigate the safety of laser use under the dental microscope. Nd:YAG, Er:YAG and diode lasers were used. The end of the tips was positioned at a distance of 5 cm from the objective lens of a dental microscope. Each eye protector was made into a flat disc, which was fixed on the lens of the microscope. The filters were placed in front of the objective lens or behind the eye lens. Transmitted energy through the microscope with or without the filters was measured. No transmitted laser energy was detected when using matched eye protectors. Mismatched eye protectors were not effective for shutting out laser energy, especially for Nd:YAG and diode lasers. None or very little laser energy was detected through the microscope even without any laser filter. Matched filters shut out all laser energy irrespective of their positions.

Miniaturized integration of a fluorescence microscope.

PubMed

Ghosh, Kunal K; Burns, Laurie D; Cocker, Eric D; Nimmerjahn, Axel; Ziv, Yaniv; Gamal, Abbas El; Schnitzer, Mark J

2011-09-11

The light microscope is traditionally an instrument of substantial size and expense. Its miniaturized integration would enable many new applications based on mass-producible, tiny microscopes. Key prospective usages include brain imaging in behaving animals for relating cellular dynamics to animal behavior. Here we introduce a miniature (1.9 g) integrated fluorescence microscope made from mass-producible parts, including a semiconductor light source and sensor. This device enables high-speed cellular imaging across ∼0.5 mm2 areas in active mice. This capability allowed concurrent tracking of Ca2+ spiking in >200 Purkinje neurons across nine cerebellar microzones. During mouse locomotion, individual microzones exhibited large-scale, synchronized Ca2+ spiking. This is a mesoscopic neural dynamic missed by prior techniques for studying the brain at other length scales. Overall, the integrated microscope is a potentially transformative technology that permits distribution to many animals and enables diverse usages, such as portable diagnostics or microscope arrays for large-scale screens.

Lower urinary tract symptoms that predict microscopic pyuria.

PubMed

Khasriya, Rajvinder; Barcella, William; De Iorio, Maria; Swamy, Sheela; Gill, Kiren; Kupelian, Anthony; Malone-Lee, James

2017-10-02

Urinary dipsticks and culture analyses of a mid-stream urine specimen (MSU) at 10 5  cfu ml -1 of a known urinary pathogen are considered the gold standard investigations for diagnosing urinary tract infection (UTI). However, the reliability of these tests has been much criticised and they may mislead. It is now widely accepted that pyuria (≥1 WBC μl -1 ) detected by microscopy of a fresh unspun, unstained specimen of urine is the best biological indicator of UTI available. We aimed to scrutinise the greater potential of symptoms analysis in detecting pyuria and UTI. Lower urinary tract symptom (LUTS) descriptions were collected from patients with chronic lower urinary tract symptoms referred to a tertiary referral unit. The symptoms informed a 39-question inventory, grouped into storage, voiding, stress incontinence and pain symptoms. All questions sought a binary yes or no response. A bespoke software package was developed to collect the data. The study was powered to a sample of at least 1,990 patients, with sufficient power to analyse 39 symptoms in a linear model with an effect size of Cohen's f 2  = 0.02, type 1 error probability = 0.05; and power (1-β); 95% where β is the probability of type 2 error). The inventory was administered to 2,050 female patients between August 2004 and November 2011. The data were collated and the following properties assessed: internal consistency, test-retest reliability, inter-observer reliability, internal responsiveness, external responsiveness, construct validity analysis and a comparison with the International Consultation on Incontinence Modular Questionnaire for female lower urinary tract symptoms (ICIQ-FLUTS). The dependent variable used as a surrogate marker of UTI was microscopic pyuria. An MSU sample was sent for routine culture. The symptoms proved reliable predictors of microscopic pyuria. In particular, voiding symptoms correlated well with microscopic pyuria (χ 2  = 88, df = 1, p < 0.001). The symptom inventory has significant psychometric characteristics as below: test-retest reliability: Cronbach's alpha was 0.981; inter-observer reliability, Cronbach's alpha was 0.995, internal responsiveness F = 221, p < 0.001, external responsiveness F = 359, df = 5, p < 0.001. The correlation coefficients for the domains of the ICIQ-FLUTS were around R = 0.5, p < 0.001. This symptoms score performed well on the standard, psychometric validation. The score changed in response to treatment and in a direction appropriate to the changes in microscopic pyuria. It correlated with measures of quality of life. It would seem to make a good candidate for monitoring treatment progress in ordinary clinical practice.

[Microscopic study of powders of hallucinogenic mushrooms--Psilocybe sp].

PubMed

Schäfer, A T

2000-01-01

The paper presents simple methods for microscopic examination and basic microchemical testing for the identification of suspect mushroom powders. The microscopic features of the most commonly cultivated and trafficked hallucinogenic genus Psilocybin are described and may serve for the decision whether any suspect material consists of such mushroom powder (and is therefore to be subjected to further analysis) or not.

Grasping the Second Law of Thermodynamics at University: The Consistency of Macroscopic and Microscopic Explanations

ERIC Educational Resources Information Center

Leinonen, Risto; Asikainen, Mervi A.; Hirvonen, Pekka E.

2015-01-01

This study concentrates on evaluating the consistency of upper-division students' use of the second law of thermodynamics at macroscopic and microscopic levels. Data were collected by means of a paper and pencil test (N = 48) focusing on the macroscopic and microscopic features of the second law concerned with heat transfer processes. The data…

Microscopic observation of magnetic bacteria in the magnetic field of a rotating permanent magnet.

PubMed

Smid, Pieter; Shcherbakov, Valeriy; Petersen, Nikolai

2015-09-01

Magnetotactic bacteria are ubiquitous and can be found in both freshwater and marine environments. Due to intracellular chains of magnetic single domain particles, they behave like swimming compass needles. In external magnetic fields like the Earth's magnetic field, a torque is acting on the chain. This will cause the bacterium to be rotated and aligned with the external field. The swimming direction of magnetotactic bacteria can be controlled with external magnetic fields, which makes it convenient to study them under a light microscope. Usually, a special set of coils arranged around a light microscope is used to control the swimming magnetotactic bacteria. Here, we present a simple mechanical system with a permanent magnet, which produces a rotating magnetic field of nearly constant amplitude in the focal plane of a light microscope. The device is placed beside the light microscope and easily adaptable to almost any microscope and thus convenient for field experiments. To describe the trajectories qualitatively, a theoretical model of the trajectories is presented. This device can be used to control the swimming direction of magnetotactic bacteria and also for studying their magnetic and hydrodynamic properties.

Application of automatic image analysis for morphometric studies of peroxisomes stained cytochemically for catalase. II. Light-microscopic application.

PubMed

Beier, K; Fahimi, H D

1987-01-01

The feasibility of the application of a television-based image analyzer, the Texture Analysis System (TAS, Leitz Wetzlar, FRG) in conjunction with a light microscope for morphometric studies of hepatic peroxisomes has been investigated. Rat liver peroxisomes were stained with the alkaline-DAB method for localization of catalase and semithin (0.25 and 1 micron) sections of plastic-embedded material were examined under an oil immersion objective. The TAS detected the peroxisomal profiles selectively and determined their morphometric parameters automatically. The same parameters were obtained also by morphometric analysis of electron micrographs from the same material. The volume density of peroxisomes determined by TAS in semithin sections of normal liver, after correction for section thickness, is quite close to the corresponding value obtained by morphometry of electron micrographs. The difference is approximately 20%. In animals treated with the hypolipidemic drug bezafibrate, which causes proliferation of peroxisomes, TAS detected readily the increase in volume density of peroxisomes in semithin sections. In comparison with electron microscopy, however, the light-microscopic approach seems to underestimate the proliferation. The lower resolution of the light microscope and overlapping of neighbouring particles in relatively thick sections used for light-microscopic analysis may account for the differences. The present study has demonstrated the usefulness of automatic image analysis in conjunction with selective cytochemical staining of peroxisomes for morphometry of this organelle in rat liver. The light-microscopic approach is not only faster but is also extremely economical by obviating the use of an electron microscope.

Telecytology: Is it possible with smartphone images?

PubMed

Sahin, Davut; Hacisalihoglu, Uguray Payam; Kirimlioglu, Saime Hale

2018-01-01

This study aimed to discuss smartphone usage in telecytology and determine intraobserver concordance between microscopic cytopathological diagnoses and diagnoses derived via static smartphone images. The study was conducted with 172 cytologic material. A pathologist captured static images of the cytology slides from the ocular lens of a microscope using a smartphone. The images were transferred via WhatsApp® to a cytopathologist working in another center who made all the microscopic cytopathological diagnoses 5-27 months ago. The cytopathologist diagnosed images on a smartphone without knowledge of their previous microscopic diagnoses. The Kappa agreement between microscopic cytopathological diagnoses and smartphone image diagnoses was determined. The average image capturing, transfer, and remote cytopathological diagnostic time for one case was 6.20 minutes. The percentage of cases whose microscopic and smartphone image diagnoses were concordant was 84.30%, and the percentage of those whose diagnoses were discordant was 15.69%. The highest Kappa agreement was observed in endoscopic ultrasound-guided fine needle aspiration (1.000), and the lowest agreement was observed in urine cytology (0.665). Patient management changed with smart phone image diagnoses at 11.04%. This study showed that easy, fast, and high-quality image capturing and transfer is possible from cytology slides using smartphones. The intraobserver Kappa agreement between the microscopic cytopathological diagnoses and remote smartphone image diagnoses was high. It was found that remote diagnosis due to difficulties in telecytology might change patient management. The developments in the smartphone camera technology and transfer software make them efficient telepathology and telecytology tools. © 2017 Wiley Periodicals, Inc.

Fluorescence microscope (Cyscope) for malaria diagnosis in pregnant women in Medani Hospital, Sudan.

PubMed

Hassan, Saad El-Din H; Haggaz, Abd Elrahium D; Mohammed-Elhassan, Ehab B; Malik, Elfatih M; Adam, Ishag

2011-09-24

Accuracy of diagnosis is the core for malaria control. Although microscopy is the gold standard in malaria diagnosis, its reliability is largely dependent on user skill. We compared performance of Cyscope fluorescence microscope with the Giemsa stained light microscopy for the diagnosis of malaria among pregnant women at Medani Hospital in Central Sudan. The area is characterized by unstable malaria transmission. Socio-demographic characteristics and obstetrics history were gathered using pre-tested questionnaires. Blood samples were collected from febrile pregnant women who were referred as malaria case following initial diagnosis by general microscopist. During the study period 128 febrile pregnant women presented at the hospital. Among them, Plasmodium falciparum malaria was detected in 82 (64.1%) and 80 (62.5%) by the Giemsa-stained light microscopy and the Cyscope fluorescence microscope, respectively. The sensitivity of the Cyscope fluorescence microscope was 97.6% (95% CI: 92.2%-99.6%). Out of 46 which were negative by Giemsa-stained light microscopy, 5 were positive by the Cyscope fluorescence microscope. This is translated in specificity of 89.1% (95% CI: 77.5%-95.9%). The positive and negative predictive value of Cyscope fluorescence microscope was 94.1% (95% CI: 87.4% -97.8%) and 95.3% (95% CI: 85.4% - 99.2%), respectively. This study has shown that Cyscope fluorescence microscope is a reliable diagnostic, sensitive and specific in diagnosing P. falciparum malaria among pregnant women in this setting. Further studies are needed to determine effectiveness in diagnosing other Plasmodium species and to compare it with other diagnostic tools e.g. rapid diagnostic tests and PCR.

A pragmatic guide to multiphoton microscope design

PubMed Central

Young, Michael D.; Field, Jeffrey J.; Sheetz, Kraig E.; Bartels, Randy A.; Squier, Jeff

2016-01-01

Multiphoton microscopy has emerged as a ubiquitous tool for studying microscopic structure and function across a broad range of disciplines. As such, the intent of this paper is to present a comprehensive resource for the construction and performance evaluation of a multiphoton microscope that will be understandable to the broad range of scientific fields that presently exploit, or wish to begin exploiting, this powerful technology. With this in mind, we have developed a guide to aid in the design of a multiphoton microscope. We discuss source selection, optical management of dispersion, image-relay systems with scan optics, objective-lens selection, single-element light-collection theory, photon-counting detection, image rendering, and finally, an illustrated guide for building an example microscope. PMID:27182429

A Digital Approach to Learning Petrology

NASA Astrophysics Data System (ADS)

Reid, M. R.

2011-12-01

In the undergraduate igneous and metamorphic petrology course at Northern Arizona University, we are employing petrographic microscopes equipped with relatively inexpensive ( $200) digital cameras that are linked to pen-tablet computers. The camera-tablet systems can assist student learning in a variety of ways. Images provided by the tablet computers can be used for helping students filter the visually complex specimens they examine. Instructors and students can simultaneously view the same petrographic features captured by the cameras and exchange information about them by pointing to salient features using the tablet pen. These images can become part of a virtual mineral/rock/texture portfolio tailored to individual student's needs. Captured digital illustrations can be annotated with digital ink or computer graphics tools; this activity emulates essential features of more traditional line drawings (visualizing an appropriate feature and selecting a representative image of it, internalizing the feature through studying and annotating it) while minimizing the frustration that many students feel about drawing. In these ways, we aim to help a student progress more efficiently from novice to expert. A number of our petrology laboratory exercises involve use of the camera-tablet systems for collaborative learning. Observational responsibilities are distributed among individual members of teams in order to increase interdependence and accountability, and to encourage efficiency. Annotated digital images are used to share students' findings and arrive at an understanding of an entire rock suite. This interdependence increases the individual's sense of responsibility for their work, and reporting out encourages students to practice use of technical vocabulary and to defend their observations. Pre- and post-course student interest in the camera-tablet systems has been assessed. In a post-course survey, the majority of students reported that, if available, they would use camera-tablet systems to capture microscope images (77%) and to make notes on images (71%). An informal focus group recommended introducing the cameras as soon as possible and having them available for making personal mineralogy/petrology portfolios. Because the stakes are perceived as high, use of the camera-tablet systems for peer-peer learning has been progressively modified to bolster student confidence in their collaborative efforts.

Safety of Microsurgery Under Loupes Versus Microscope: A Head-to-Head Comparison of 2 Surgeons With Similar Experiences.

PubMed

Ehanire, Tosan; Singhal, Dhruv; Mast, Bruce; Leyngold, Mark

2018-01-24

Microsurgery is performed using either the operating microscope or loupe magnification. Use of the operating microscope is considered the "criterion standard"; however, loupes are emerging as a safe and reliable technique to perform microsurgery. The purpose of this study was to analyze the safety of microsurgery under loupe magnification compared with the microscope. Previous studies discussing the safety of loupe magnification during microsurgery have been published; however, this is the first study to compare free flap outcomes from 2 surgeons at the same institution, each using their respective technique. The outcomes were compared by retrospective chart review of 116 patients, and 148 microvascular free tissue transfers were performed between January 1, 2013, and July 15, 2016, by 2 surgeons (D.S.) and (M.L.). Patients' demographics, free flap failure rate, and other surgical complications were analyzed. Statistical significance was determined by unpaired t test, and χ analysis was used to determine statistical significance in proportions between groups. Thirty-eight percent of flaps were performed under ×3.5 loupe magnification and 62% under the operating microscope. Most free flaps used were deep inferior epigastric perforator or muscle sparing transverse rectus abdominis flaps (52%) for breast reconstruction, remainder of free flaps included ALT, radial forearm, and latissimus dorsi for a variety of reconstructive applications. There was no significant difference between the loupes and microscope groups in intraoperative anastomotic revision rate (27% vs 17%), postoperative arterial or venous thrombosis (4.4% vs 2.6%, 5.4% vs 2.2%), flap loss (3.6% vs 2.2%), or median length of stay (6 days vs 6.5 days). The loupe magnification group had statistically significant shorter setup time (20 minutes, P < 0.01). Consistent with previously reported studies, we found no statistical difference in free flap outcomes and safety under loupe magnification compared with the operating microscope. This is the first study to demonstrate these findings with 2 microsurgeons both in their first 3 years in practice, with similar training and experience, operating at the same institution and given the same resources, each using either microscopes or loupes for microsurgery.

Sole Dependence on Urine Testing Strips and the Ability to Identify Clinically Significant Disease: Challenging the Current Paradigm for Heme Detection in General Clinical Situations.

PubMed

Rothschild, Bruce

2016-05-01

The ability of health care professionals to provide patient care is potentially compromised when predicated on untested, although longstanding, perspectives. One such example is urinalysis testing, which has been currently simplified to use only urine testing strips for detection of microscopic hematuria. To determine whether urine testing strips are sufficient for identification of clinically significant findings in urinalysis. To determine the presence of microscopic hematuria, I examined a collection of urine specimens that had tested heme negative during the 3-month study period. Of the 342 patients from whom urine specimens were examined during this interval, 50 had microscopic hematuria, despite having tested negative for heme via urine testing strip. Also, 30% were not receiving any medication known to produce microscopic hematuria, and 18% had clinically significant pathology. Diagnosis of significant clinical pathologic manifestations would have been compromised had microscopic examination not been performed on the urine specimens from the cohort individuals. Examination of the novel approach of including microscopic examination of specimens in a specific clinical situation challenges the dominant paradigm of reliance on assaying using urine testing strips only, revealing that the current method is not only unreliable for determining microscopic hematuria but also is less than optimal in general clinical practice. The findings of this study provide evidence of the importance of microscopic evaluation as a routine component of urinalysis. © American Society for Clinical Pathology, 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Simulation model calibration and validation : phase II : development of implementation handbook and short course.

DOT National Transportation Integrated Search

2006-01-01

A previous study developed a procedure for microscopic simulation model calibration and validation and evaluated the procedure via two relatively simple case studies using three microscopic simulation models. Results showed that default parameters we...

Big Data and Deep data in scanning and electron microscopies: functionality from multidimensional data sets

DOE PAGES

Belianinov, Alex; Vasudevan, Rama K; Strelcov, Evgheni; ...

2015-05-13

The development of electron, and scanning probe microscopies in the second half of the twentieth century have produced spectacular images of internal structure and composition of matter with, at nanometer, molecular, and atomic resolution. Largely, this progress was enabled by computer-assisted methods of microscope operation, data acquisition and analysis. The progress in imaging technologies in the beginning of the twenty first century has opened the proverbial floodgates of high-veracity information on structure and functionality. High resolution imaging now allows information on atomic positions with picometer precision, allowing for quantitative measurements of individual bond length and angles. Functional imaging often leadsmore » to multidimensional data sets containing partial or full information on properties of interest, acquired as a function of multiple parameters (time, temperature, or other external stimuli). Here, we review several recent applications of the big and deep data analysis methods to visualize, compress, and translate this data into physically and chemically relevant information from imaging data.« less

Crowdsourcing the creation of image segmentation algorithms for connectomics.

PubMed

Arganda-Carreras, Ignacio; Turaga, Srinivas C; Berger, Daniel R; Cireşan, Dan; Giusti, Alessandro; Gambardella, Luca M; Schmidhuber, Jürgen; Laptev, Dmitry; Dwivedi, Sarvesh; Buhmann, Joachim M; Liu, Ting; Seyedhosseini, Mojtaba; Tasdizen, Tolga; Kamentsky, Lee; Burget, Radim; Uher, Vaclav; Tan, Xiao; Sun, Changming; Pham, Tuan D; Bas, Erhan; Uzunbas, Mustafa G; Cardona, Albert; Schindelin, Johannes; Seung, H Sebastian

2015-01-01

To stimulate progress in automating the reconstruction of neural circuits, we organized the first international challenge on 2D segmentation of electron microscopic (EM) images of the brain. Participants submitted boundary maps predicted for a test set of images, and were scored based on their agreement with a consensus of human expert annotations. The winning team had no prior experience with EM images, and employed a convolutional network. This "deep learning" approach has since become accepted as a standard for segmentation of EM images. The challenge has continued to accept submissions, and the best so far has resulted from cooperation between two teams. The challenge has probably saturated, as algorithms cannot progress beyond limits set by ambiguities inherent in 2D scoring and the size of the test dataset. Retrospective evaluation of the challenge scoring system reveals that it was not sufficiently robust to variations in the widths of neurite borders. We propose a solution to this problem, which should be useful for a future 3D segmentation challenge.

Structure–property relationships in atomic-scale junctions: Histograms and beyond

DOE PAGES

Mark S. Hybertsen; Venkataraman, Latha

2016-03-03

Over the past 10 years, there has been tremendous progress in the measurement, modeling and understanding of structure–function relationships in single molecule junctions. Numerous research groups have addressed significant scientific questions, directed both to conductance phenomena at the single molecule level and to the fundamental chemistry that controls junction functionality. Many different functionalities have been demonstrated, including single-molecule diodes, optically and mechanically activated switches, and, significantly, physical phenomena with no classical analogues, such as those based on quantum interference effects. Experimental techniques for reliable and reproducible single molecule junction formation and characterization have led to this progress. In particular, themore » scanning tunneling microscope based break-junction (STM-BJ) technique has enabled rapid, sequential measurement of large numbers of nanoscale junctions allowing a statistical analysis to readily distinguish reproducible characteristics. Furthermore, harnessing fundamental link chemistry has provided the necessary chemical control over junction formation, enabling measurements that revealed clear relationships between molecular structure and conductance characteristics.« less

Structure–property relationships in atomic-scale junctions: Histograms and beyond

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mark S. Hybertsen; Venkataraman, Latha

Over the past 10 years, there has been tremendous progress in the measurement, modeling and understanding of structure–function relationships in single molecule junctions. Numerous research groups have addressed significant scientific questions, directed both to conductance phenomena at the single molecule level and to the fundamental chemistry that controls junction functionality. Many different functionalities have been demonstrated, including single-molecule diodes, optically and mechanically activated switches, and, significantly, physical phenomena with no classical analogues, such as those based on quantum interference effects. Experimental techniques for reliable and reproducible single molecule junction formation and characterization have led to this progress. In particular, themore » scanning tunneling microscope based break-junction (STM-BJ) technique has enabled rapid, sequential measurement of large numbers of nanoscale junctions allowing a statistical analysis to readily distinguish reproducible characteristics. Furthermore, harnessing fundamental link chemistry has provided the necessary chemical control over junction formation, enabling measurements that revealed clear relationships between molecular structure and conductance characteristics.« less

Big Data and Deep data in scanning and electron microscopies: functionality from multidimensional data sets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belianinov, Alex; Vasudevan, Rama K; Strelcov, Evgheni

The development of electron, and scanning probe microscopies in the second half of the twentieth century have produced spectacular images of internal structure and composition of matter with, at nanometer, molecular, and atomic resolution. Largely, this progress was enabled by computer-assisted methods of microscope operation, data acquisition and analysis. The progress in imaging technologies in the beginning of the twenty first century has opened the proverbial floodgates of high-veracity information on structure and functionality. High resolution imaging now allows information on atomic positions with picometer precision, allowing for quantitative measurements of individual bond length and angles. Functional imaging often leadsmore » to multidimensional data sets containing partial or full information on properties of interest, acquired as a function of multiple parameters (time, temperature, or other external stimuli). Here, we review several recent applications of the big and deep data analysis methods to visualize, compress, and translate this data into physically and chemically relevant information from imaging data.« less

Sub-micron materials characterization using near-field optics

NASA Astrophysics Data System (ADS)

Blodgett, David Wesley

1998-12-01

High-resolution sub-surface materials characterization and inspection are critical in the microelectronics and thin films industries. To this end, a technique is described that couples the bulk property measurement capabilities of high-frequency ultrasound with the high-resolution surface imaging capabilities of the near-field optical microscope. Sensing bulk microstructure variations in the material, such as grain boundaries, requires a detection footprint smaller than the variation itself. The near-field optical microscope, with the ability to exceed the diffraction limit in optical resolution, meets this requirement. Two apertureless near-field optical microscopes, on-axis and off-axis illumination, have been designed and built. Near-field and far-field approach curves for both microscopes are presented. The sensitivity of the near-field approach curve was 8.3 muV/nm. Resolution studies for the near-field microscope indicate optical resolutions on the order of 50 nm, which exceeds the diffraction limit. The near-field microscope has been adapted to detect both contact-transducer-generated and laser-generated ultrasound. The successful detection of high-frequency ultrasound with the near-field optical microscope demonstrates the potential of this technique.

Refining Students' Explanations of an Unfamiliar Physical Phenomenon-Microscopic Friction

NASA Astrophysics Data System (ADS)

Corpuz, Edgar De Guzman; Rebello, N. Sanjay

2017-08-01

The first phase of this multiphase study involves modeling of college students' thinking of friction at the microscopic level. Diagnostic interviews were conducted with 11 students with different levels of physics backgrounds. A phenomenographic approach of data analysis was used to generate categories of responses which subsequently were used to generate a model of explanation. Most of the students interviewed consistently used mechanical interactions in explaining microscopic friction. According to these students, friction is due to the interlocking or rubbing of atoms. Our data suggest that students' explanations of microscopic friction are predominantly influenced by their macroscopic experiences. In the second phase of the research, teaching experiment was conducted with 18 college students to investigate how students' explanations of microscopic friction can be refined by a series of model-building activities. Data were analyzed using Redish's two-level transfer framework. Our results show that through sequences of hands-on and minds-on activities, including cognitive dissonance and resolution, it is possible to facilitate the refinement of students' explanations of microscopic friction. The activities seemed to be productive in helping students activate associations that refine their ideas about microscopic friction.

A next generation positron microscope and a survey of candidate samples for future positron studies

NASA Astrophysics Data System (ADS)

Dull, Terry Lou

A positron microscope has been constructed and is nearing the conclusion of its assembly and testing. The instrument is designed to perform positron and electron microscopy in both scanning and magnifying modes. In scanning mode, a small beam of particles is rastered across the target and the amplitude of a positron or electron related signal is recorded as a function of position. For positrons this signal may come from Doppler Broadening Spectroscopy, Reemitted Positron Spectroscopy or Positron Annihilation Lifetime Spectroscopy. For electrons this signal may come from the number of secondary electrons or Auger Electron Spectroscopy. In magnifying mode an incident beam of particles is directed onto the target and emitted particles, either secondary electrons or reemitted positrons, are magnified to form an image. As a positron microscope the instrument will primarily operate in magnifying mode, as a positron reemission microscope. As an electron microscope the instrument will be able to operate in both magnifying and scanning modes. Depth-profiled Doppler Broadening Spectroscopy studies using a non-microscopic low-energy positron beam have also been performed on a series of samples to ascertain the applicability of positron spectroscopies and/or microscopy to their study. All samples have sub-micron film and/or feature size and thus are only susceptible to positron study with low-energy beams. Several stoichiometries and crystallinities of chalcogenide thin films (which can be optically reversibly switched between crystalline states) were studied and a correlation was found to exist between the amorphous/FCC S-parameter difference and the amorphous/FCC switching time. Amorphous silicon films were studied in an attempt to observe the well-established Staebler-Wronski effect as well as the more controversial photodilatation effect. However, DBS was not able to detect either effect. The passive oxide films on titanium and aluminum were studied in an attempt to verify the Point Defect Model, a detailed, but as yet microscopically unconfirmed, theory of the corrosive breakdown of passive films. DBS results supportive of the PDM were observed. Graphitic carbon fibers were also studied and DBS indicated the presence of a 200 nm thick outer fiber skin possibly characterized by a high degree of graphitic crystallite alignment.

Combination of hand-held probe and microscopy for fluorescence guided surgery in the brain tumor marginal zone.

PubMed

Richter, Johan C O; Haj-Hosseini, Neda; Hallbeck, Martin; Wårdell, Karin

2017-06-01

Visualization of the tumor is crucial for differentiating malignant tissue from healthy brain during surgery, especially in the tumor marginal zone. The aim of the study was to introduce a fluorescence spectroscopy-based hand-held probe (HHF-probe) for tumor identification in combination with the fluorescence guided resection surgical microscope (FGR-microscope), and evaluate them in terms of diagnostic performance and practical aspects of fluorescence detection. Eighteen operations were performed on 16 patients with suspected high-grade glioma. The HHF-probe and the FGR-microscope were used for detection of protoporphyrin (PpIX) fluorescence induced by 5-aminolevulinic acid (5-ALA) and evaluated against histopathological analysis and visual grading done through the FGR-microscope by the surgeon. A ratio of PpIX fluorescence intensity to the autofluorescence intensity (fluorescence ratio) was used to quantify the spectra detected by the probe. Fluorescence ratio medians (range 0 - 40) measured by the probe were related to the intensity of the fluorescence in the FGR-microscope, categorized as "none" (0.3, n=131), "weak" (1.6, n=34) and "strong" (5.4, n=28). Of 131 "none" points in the FGR-microscope, 88 (67%) exhibited fluorescence with the HHF-probe. For the tumor marginal zone, the area under the receiver operator characteristics (ROC) curve was 0.49 for the FGR-microscope and 0.65 for the HHF-probe. The probe was integrated in the established routine of tumor resection using the FGR-microscope. The HHF-probe was superior to the FGR-microscope in sensitivity; it detected tumor remnants after debulking under the FGR-microscope. The combination of the HHF-probe and the FGR-microscope was beneficial especially in the tumor marginal zone. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

The current status of microscopical hair comparisons.

PubMed

Rowe, W F

2001-12-08

Although the microscopical comparison of human hairs has been accepted in courts of law for over a century, recent advances in DNA technology have called this type of forensic examination into question. In a number of cases, post-conviction DNA testing has exonerated defendants who were convicted in part on the results of microscopical hair comparisons. A federal judge has held a Daubert hearing on the microscopical comparison of human hairs and has concluded that this type of examination does not meet the criteria for admission of scientific evidence in federal courts. A review of the available scientific literature on microscopical hair comparisons (including studies conducted by the Royal Canadian Mounted Police and the Federal Bureau of Investigation) leads to three conclusions: (1) microscopical comparisons of human hairs can yield scientifically defensible conclusions that can contribute to criminal investigations and criminal prosecutions, (2) the reliability of microscopical hair comparisons is strongly affected by the training of the forensic hair examiner, (3) forensic hair examiners cannot offer estimates of the probability of a match of a questioned hair with a hair from a randomly selected person. In order for microscopical hair examinations to survive challenges under the U.S. Supreme Court's Daubert decision, hair microscopists must be better trained and undergo frequent proficiency testing. More research on the error rates of microscopical hair comparisons should be undertaken, and guidelines for the permissible interpretations of such comparisons should be established. Until these issues have been addressed and satisfactorily resolved, microscopical hair comparisons should be regarded by law enforcement agencies and courts of law as merely presumptive in nature, and all microscopical hair comparisons should be confirmed by nuclear DNA profiling or mitochondrial DNA sequencing.

Molecular engineering of colloidal liquid crystals using DNA origami

NASA Astrophysics Data System (ADS)

Siavashpouri, Mahsa; Wachauf, Christian; Zakhary, Mark; Praetorius, Florian; Dietz, Hendrik; Dogic, Zvonimir

Understanding the microscopic origin of cholesteric phase remains a foundational, yet unresolved problem in the field of liquid crystals. Lack of experimental model system that allows for the systematic control of the microscopic chiral structure makes it difficult to investigate this problem for several years. Here, using DNA origami technology, we systematically vary the chirality of the colloidal particles with molecular precision and establish a quantitative relationship between the microscopic structure of particles and the macroscopic cholesteric pitch. Our study presents a new methodology for predicting bulk behavior of diverse phases based on the microscopic architectures of the constituent molecules.

The microscopes of Antoni van Leeuwenhoek.

PubMed

van Zuylen, J

1981-03-01

The seventeenth-century Dutch microscopist, Antoni van Leeuwenhoek, was the first man to make a protracted study of microscopical objects, and, unlike his contemporary Robert Hooke, he viewed by transmitted light. Leeuwenhoek made over 500 of his own, curious, simple microscopes, but now only nine are known to exist. The exact nature of the lenses Leeuwenhoek made, has for long been a puzzle. The existing microscopes have now been examined in detail, and their optical characteristics measured and tabulated. It is proposed that the lens of highest magnification, x 266, was made using a special blown bubble technique.

Enhancing Learning Objectives by Use of Simple Virtual Microscopic Slides in Cellular Physiology and Histology: Impact and Attitudes

ERIC Educational Resources Information Center

Anyanwu, Godson Emeka; Agu, Augustine Uchechukwu; Anyaehie, Ugochukwu Bond

2012-01-01

The impact and perception of students on the use of a simple, low technology-driven version of a virtual microscope in teaching and assessments in cellular physiology and histology were studied. Its impact on the time and resources of the faculty were also assessed. Simple virtual slides and conventional microscopes were used to conduct the same…

Fermi Gas Microscope

NASA Astrophysics Data System (ADS)

Setiawan, Widagdo

Recent advances in using microscopes in ultracold atom experiment have allowed experimenters for the first time to directly observe and manipulate individual atoms in individual lattice sites. This technique enhances our capability to simulate strongly correlated systems such as Mott insulator and high temperature superconductivity. Currently, all ultracold atom experiments with high resolution imaging capability use bosonic atoms. In this thesis, I present our progress towards creating the fermionic version of the microscope experiment which is more suitable for simulating real condensed matter systems. Lithium is ideal due to the existence of both fermionic and bosonic isotopes, its light mass, which means faster experiment time scales that suppresses many sources of technical noise, and also due to the existence of a broad Feshbach resonance, which can be used to tune the inter-particle interaction strength over a wide range from attractive, non-interacting, and repulsive interactions. A high numerical aperture objective will be used to image and manipulate the atoms with single lattice site resolution. This setup should allow us to implement the Hubbard hamiltonian which could describe interesting quantum phases such as antiferromagnetism, d-wave superfluidity, and high temperature superconductivity. I will also discuss the feasibility of the Raman sideband cooling method for cooling the atoms during the imaging process. We have also developed a new electronic control system to control the sequence of the experiment. This electronic system is very scalable in order to keep up with the increasing complexity of atomic physics experiments. Furthermore, the system is also designed to be more precise in order to keep up with the faster time scale of lithium experiment.

An experimental investigation on the three-point bending behavior of composite laminate

NASA Astrophysics Data System (ADS)

A, Azzam; W, Li

2014-08-01

The response of composite laminate structure to three-point bending load was investigated by subjecting two types of stacking sequences of composite laminate structure by using electronic universal tester (Type: WDW-20) machine. Optical microscope was selected in order to characterize bending damage, delamination, and damage shapes in composite laminate structures. The results showed that the [0/90/-45/45]2s exhibits a brittle behavior, while other laminates exhibit a progressive failure mode consisting of fiber failure, debonding (splitting), and delamination. The [45/45/90/0]2s laminate has a highly nonlinear load- displacement curve due to compressive yielding.

Simultaneous Bilateral Anterior and Posterior Lenticonus in Alport Syndrome.

PubMed

Bamotra, Ravi Kant; Meenakshi; Kesarwani, Prem Chandra; Qayum, Shazia

2017-08-01

Alport syndrome is an inherited disease characterized by progressive renal failure, hearing loss, and ocular abnormalities like anterior lenticonus, corneal opacities, cataract, central perimacular and peripheral coalescing fleck retinopathies, and temporal retinal thinning. Although anterior lenticonus is common in Alport syndrome, simultaneous anterior and posterior lenticonus is a rare presentation. We report a case of a 22-year-old female with simultaneous anterior and posterior lenticonus presentation in which ocular examination lead to the detection of Alport syndrome. The patient had sensorineural deafness as well as microscopic haematuria. Clear lens extraction was performed in both eyes to eliminate lenticular irregular astigmatism for visual rehabilitation.

Ion beam sputter modification of the surface morphology of biological implants

NASA Technical Reports Server (NTRS)

Weigand, A. J.; Banks, B. A.

1976-01-01

The surface chemistry and texture of materials used for biological implants may significantly influence their performance and biocompatibility. Recent interest in the microscopic control of implant surface texture has led to the evaluation of ion beam sputtering as a potentially useful surface roughening technique. Ion sources, similar to electron bombardment ion thrusters designed for propulsive applications, are used to roughen the surfaces of various biocompatible alloys or polymer materials. These materials are typically used for dental implants, orthopedic prostheses, vascular prostheses, and artificial heart components. Masking techniques and resulting surface textures are described along with progress concerning evaluation of the biological response to the ion beam sputtered surfaces.

Ion-beam-sputter modification of the surface morphology of biological implants

NASA Technical Reports Server (NTRS)

Weigand, A. J.; Banks, B. A.

1977-01-01

The surface chemistry and texture of materials used for biological implants may significantly influence their performance and biocompatibility. Recent interest in the microscopic control of implant surface texture has led to the evaluation of ion-beam sputtering as a potentially useful surface roughening technique. Ion sources, similar to electron-bombardment ion thrusters designed for propulsive applications, are used to roughen the surfaces of various biocompatible alloys or polymer materials. These materials are typically used for dental implants, orthopedic prostheses, vascular prostheses, and artificial heart components. Masking techniques and resulting surface textures are described along with progress concerning evaluation of the biological response to the ion-beam-sputtered surfaces.

Availability of a library of infrared (2.1-25.0 μm) mineral spectra

USGS Publications Warehouse

Salisbury, John W.; Walter, Louis S.; Vergo, Norma

1989-01-01

All previously published libraries of infrared mineral spectra are in the form of transmittance.  Reflectance spectra are, however, more useful for remote sensing and some potential laboratory applications, such as the use of an infrared microscope for mineral identification on polished sections. This note points out that construction of a new library of infrared (2.1-25.0 μm) mineral spectra is in progress. Both transmittance and reflectance measurements of a selection of 63 different, well-characteized minerals have been published to date. These data are available in both hard copy and digital form.

The reconstructive microsurgery ladder in orthopaedics.

PubMed

Tintle, Scott M; Levin, L Scott

2013-03-01

Since the advent of the operating microscope by Julius Jacobson in 1960, reconstructive microsurgery has become an integral part of extremity reconstruction and orthopaedics. During World War I, with the influx of severe extremity trauma Harold Gillies introduced the concept of the reconstructive ladder for wound closure. The concept of the reconstructive ladder goes from simple to complex means of attaining wound closure. Over the last half century microsurgery has continued to evolve and progress. We now have a microsurgical reconstructive ladder. The microsurgical reconstruction ladder is based upon the early work on revascularization and replantation extending through the procedures that are described in this article. Copyright © 2013. Published by Elsevier Ltd.

Reviews in Modern Astronomy: Vol. 15: JENAM 2001: Astronomy with Large Telescopes from Ground and Space

NASA Astrophysics Data System (ADS)

Schielicke, Reinhard E.

2002-11-01

This 15th volume in the annual series on recent developments and scientific progress in astronomy and astrophysics contains fourteen invited reviews presented during the Joint European and National Astronomical Meeting JENAM 2001, held in Munich, Germany. Readers also learn about the lecture on macro- and microscopic views of nearby galaxies given by Keiichi Kodaira, Japan, who was awarded the Karl Schwarzschild medal 2001. Further contributions on the topic provide the latest results on the search for extra-solar planets, formation of stars and galaxies, physics of active galactic nuclei, as well as new telescopes and sensor technologies for various wavelengths.

Screening Fluorescent Voltage Indicators with Spontaneously Spiking HEK Cells

PubMed Central

Venkatachalam, Veena; Kralj, Joel M.; Dib-Hajj, Sulayman D.; Waxman, Stephen G.; Cohen, Adam E.

2013-01-01

Development of improved fluorescent voltage indicators is a key challenge in neuroscience, but progress has been hampered by the low throughput of patch-clamp characterization. We introduce a line of non-fluorescent HEK cells that stably express NaV 1.3 and KIR 2.1 and generate spontaneous electrical action potentials. These cells enable rapid, electrode-free screening of speed and sensitivity of voltage sensitive dyes or fluorescent proteins on a standard fluorescence microscope. We screened a small library of mutants of archaerhodopsin 3 (Arch) in spiking HEK cells and identified two mutants with greater voltage-sensitivity than found in previously published Arch voltage indicators. PMID:24391999

Spherical microglass particle impingement studies of thermoplastic materials at normal incidence

NASA Technical Reports Server (NTRS)

Veerabhadra Rao, P.; Buckley, D. H.

1984-01-01

Light optical and scanning electron microscope studies were conducted to characterize the erosion resistance of polymethyl methacrylate (PMMA), polycarbonate (PC), polytetrafluoroethylene (PTFE) and ultra-high-molecular-weight-polyethylene (UHMWPE). Erosion was caused by a jet of spherical micro-glass beads at normal impact. During the initial stages of damage, the surfaces of these materials were studied using a profilometer. Material buildup above the original surface was observed on PC and PMMA. As erosion progressed, this buildup disappeared as the pit became deeper. Little or no buildup was observed on PTFE and on UHMWPE. UHMWPE and PTFE are the most resistant materials and PMMA the least. Favorable properties for high erosion resistance seem to be high values of ultimate elongation, and strain energy and a low value of the modulus of elasticity. Erosion-rate-versus-time curves of PC and PTFE exhibit incubation, acceleration and steady state periods. A continuously increasing erosion rate period was observed however for PMMA instead of a steady state period. At early stages of damage and at low impact pressure material removal mechanisms appear to be similar to those for metallic materials.

Spherical micro-glass particle impingement studies of thermoplastic materials at normal incidence

NASA Technical Reports Server (NTRS)

Rao, P. V.; Buckley, D. H.

1983-01-01

Light optical and scanning electron microscope studies were conducted to characterize the erosion resistance of polymethyl methacrylate (PMMA), polycarbonate (PC), polytetrafluoroethylene (PTFE) and ultra-high-molecular-weight-polyethylene (UHMWPE). Erosion was caused by a jet of spherical micro-glass beads at normal impact. During the initial stages of damage, the surfaces of these materials were studied using a profilometer. Material buildup above the original surface was observed on PC and PMMA. As erosion progressed, this buildup disappeared as the pit became deeper. Little or no buildup was observed on PTFE and on UHMWPE. UHMWPE and PTFE are the most resistant materials and PMMA the least. Favorable properties for high erosion resistance seem to be high values of ultimate elongation, and strain energy and a low value of the modulus of elasticity. Erosion-rate-versus-time curves of PC and PTFE exhibit incubation, acceleration and steady state periods. A continuously increasing erosion rate period was observed however for PMMA instead of a steady state period. At early stages of damage and at low impact pressure material removal mechanisms appear to be similar to those for metallic materials.

The head-mounted microscope.

PubMed

Chen, Ting; Dailey, Seth H; Naze, Sawyer A; Jiang, Jack J

2012-04-01

Microsurgical equipment has greatly advanced since the inception of the microscope into the operating room. These advancements have allowed for superior surgical precision and better post-operative results. This study focuses on the use of the Leica HM500 head-mounted microscope for the operating phonosurgeon. The head-mounted microscope has an optical zoom from 2× to 9× and provides a working distance from 300 mm to 700 mm. The headpiece, with its articulated eyepieces, adjusts easily to head shape and circumference, and offers a focus function, which is either automatic or manually controlled. We performed five microlaryngoscopic operations utilizing the head-mounted microscope with successful results. By creating a more ergonomically favorable operating posture, a surgeon may be able to obtain greater precision and success in phonomicrosurgery. Phonomicrosurgery requires the precise manipulation of long-handled cantilevered instruments through the narrow bore of a laryngoscope. The head-mounted microscope shortens the working distance compared with a stand microscope, thereby increasing arm stability, which may improve surgical precision. Also, the head-mounted design permits flexibility in head position, enabling operator comfort, and delaying musculoskeletal fatigue. A head-mounted microscope decreases the working distance and provides better ergonomics in laryngoscopic microsurgery. These advances provide the potential to promote precision in phonomicrosurgery. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

CUSUM analysis of learning curves for the head-mounted microscope in phonomicrosurgery.

PubMed

Chen, Ting; Vamos, Andrew C; Dailey, Seth H; Jiang, Jack J

2016-10-01

To observe the learning curve of the head-mounted microscope in a phonomicrosurgery simulator using cumulative summation (CUSUM) analysis, which incorporates a magnetic phonomicrosurgery instrument tracking system (MPTS). Retrospective case series. Eight subjects (6 medical students and 2 surgeons inexperienced in phonomicrosurgery) operated on phonomicrosurgical simulation cutting tasks while using the head-mounted microscope for 400 minutes total. Two 20-minute sessions occurred each day for 10 total days, with operation quality (Qs ) and completion time (T) being recorded after each session. Cumulative summation analysis of Qs and T was performed by using subjects' performance data from trials completed using a traditional standing microscope as success criteria. The motion parameters from the head-mounted microscope were significantly better than the standing microscope (P < 0.01), but T was longer than that from the standing microscope (P < 0.01). No subject successfully adapted to the head-mounted microscope, as assessed by CUSUM analysis. Cumulative summation analysis can objectively monitor the learning process associated with a phonomicrosurgical simulator system, ultimately providing a tool to assess learning status. Also, motion parameters determined by our MPTS showed that, although the head-mounted microscope provides better motion control, worse Qs and longer T resulted. This decrease in Qs is likely a result of the relatively unstable visual environment that it provides. Overall, the inexperienced surgeons participating in this study failed to adapt to the head-mounted microscope in our simulated phonomicrosurgery environment. 4 Laryngoscope, 126:2295-2300, 2016. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

CCS52A2/FZR1, a cell cycle regulator, is an essential factor for shoot apical meristem maintenance in Arabidopsis thaliana.

PubMed

Liu, Yajie; Ye, Wei; Li, Beibei; Zhou, Xiaojing; Cui, Yuhai; Running, Mark P; Liu, Kede

2012-08-08

Cell division and cell fate decisions regulate organ formation and function in plant growth and development. It is still unclear how specific meristematic regulatory networks operate with the cell cycle machinery to translate stem cell identity and maintenance into cellular behavior. In this study, we address these questions by analysis of a shoot apex defective mutant, namely xcm9. Phenotypic analysis of the xcm9 mutant reveals concomitant premature termination of floral shoots with frequent bifurcation of the shoot apices, stems, and flowers. Microscopic observations show irregular cell organization in shoot apical meristems of xcm9. Positional cloning revealed that xcm9 is a loss of function allele of the CCS52A2/FZR1 gene, which has previously been implicated in root development. Expression analysis demonstrated that CCS52A2 maintains a higher transcriptional expression level in actively dividing tissue. Genetic studies indicated that the CCS52A2 gene functions together with WUSCHEL (WUS) and CLAVATA3 (CLV3) in regulating the development of the shoot meristem, and also contributes to this regulation together with the chromatin remodeling pathway. In addition, fewer xcm9 cells express CYCLIN B1:1, showing that cell cycle progression is disrupted in the mutant. We propose that the CCS52A2 gene is a mediator that functions together with meristematic genes to regulate meristem organization, and cross-functions with chromatin regulators in cell cycle progression during shoot apical meristem development.

Clinical and histological findings of cutaneous wound healing in the red-eared slider turtle (Trachemys scripta elegans) housed in unheated outdoor enclosures.

PubMed

Negrini, Joao; Ginel, Pedro J; Novales, Manuel; Guerra, Rafael; Mozos, Elena

2016-10-01

Cutaneous wounds are common in chelonians. The clinical and histological features of wound healing in these species are not well described and this prevents evaluation of new therapies. To describe clinical and histopathological features of cutaneous wound healing in the red-eared slider turtle (Trachemys scripta elegans). Twenty four healthy adult females housed in outdoor facilities with free access to water and exposed to daily variations in temperature. Full thickness 6 mm skin biopsy punch wounds were created in the rear limbs. The turtles were assigned to Group 1 (n = 12 for clinical evaluation) and Group 2 (n = 12 for microscopic study). Group 1 was photographed on Day 1 and weekly, until 28 days post wounding. Wound retraction was expressed as the percentage of perimeter reduction. For Group 2, three skin wounds were sampled at 2, 7, 14, 21, 28, 42, 60 and 135 days post wounding for histological study. The avidin-biotin-peroxidase (ABC) staining method was used to evaluate five commercial antibodies. Wound contraction was limited; crust persisted at least 28 days. Re-epithelialization was complete by Day 14 in many animals; active inflammation persisted until 28 days; connective tissue re-constitution and remodelling was achieved from 42 to 135 days. Antibodies AE1/AE3, Factor VIII, MAC 387, CD3 and NCL-MSA showed cross reactivity with the cell counterpart in turtle tissues. Second intention wound healing progressed slowly and with an indolent behaviour. Microscopically there was marked overlapping of the inflammatory and proliferative phases over a long time period. © 2016 ESVD and ACVD.

Microvascular distribution in the ocular conjunctiva and digestive tract in an experimental setting.

PubMed

Pranskūnas, Andrius; Pilvinis, Vidas; Dambrauskas, Žilvinas; Rasimavičiūtė, Renata; Milieškaitė, Eglė; Bubulis, Algimantas; Veikutis, Vincentas; Vaitkaitis, Dinas; Boerma, E Christiaan

2012-01-01

Recently improved microcirculatory imaging techniques, such as orthogonal polarization spectral (OPS) and its technical successor sidestream dark field (SDF) imaging, in handheld devices have allowed a direct observation of the microcirculation at the bedside. Usually a cut-off of 20 µm in diameter is used to differentiate small vessels (mainly capillaries) from large vessels (mainly venules) during this technique. We hypothesized that it was possible to measure the small vessels with a considerably smaller inner diameter. Images of the sublingual, conjunctival, jejunal, and rectal mucosa microcirculation were obtained with SDF videomicroscopy (Microscan®, Microvision Medical, Amsterdam, the Netherlands). Using the validated software, the length and diameter of microvessels were manually traced with a computer-generated line. All vessels were divided into the groups according to the inner diameter. A total of 156 SDF images of the sublingual, ocular conjunctival, jejunal, and rectal mucosa were taken in 13 pigs. The length of microscopic vessels progressively increased with a decrease in the vessel diameter less than 8 mm in all the lodges, such as sublingual (80.6% of total vessel length), ocular conjunctival (76.5% of total vessel length), jejunal (99.8% of total vessel length), and rectal (97.8% of total vessel length), due to capillary network formation. There was no significant difference in the distribution of vessels from 0 to 10 µm in diameter comparing sublingual and eye conjunctival as well as jejunal and rectal mucosa. In pigs, small-diameter microscopic vessels (<10 µm) dominated in all the studied lodges (sublingual, ocular conjunctival, jejunal, and rectal mucosa), and this is evidence to establish a new cut-off for capillaries in microcirculatory analysis of SDF imaging in experimental and clinical studies.

The Strategic Environment Assessment bibliographic network: A quantitative literature review analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caschili, Simone, E-mail: s.caschili@ucl.ac.uk; De Montis, Andrea; Ganciu, Amedeo

2014-07-01

Academic literature has been continuously growing at such a pace that it can be difficult to follow the progression of scientific achievements; hence, the need to dispose of quantitative knowledge support systems to analyze the literature of a subject. In this article we utilize network analysis tools to build a literature review of scientific documents published in the multidisciplinary field of Strategic Environment Assessment (SEA). The proposed approach helps researchers to build unbiased and comprehensive literature reviews. We collect information on 7662 SEA publications and build the SEA Bibliographic Network (SEABN) employing the basic idea that two publications are interconnectedmore » if one cites the other. We apply network analysis at macroscopic (network architecture), mesoscopic (sub graph) and microscopic levels (node) in order to i) verify what network structure characterizes the SEA literature, ii) identify the authors, disciplines and journals that are contributing to the international discussion on SEA, and iii) scrutinize the most cited and important publications in the field. Results show that the SEA is a multidisciplinary subject; the SEABN belongs to the class of real small world networks with a dominance of publications in Environmental studies over a total of 12 scientific sectors. Christopher Wood, Olivia Bina, Matthew Cashmore, and Andrew Jordan are found to be the leading authors while Environmental Impact Assessment Review is by far the scientific journal with the highest number of publications in SEA studies. - Highlights: • We utilize network analysis to analyze scientific documents in the SEA field. • We build the SEA Bibliographic Network (SEABN) of 7662 publications. • We apply network analysis at macroscopic, mesoscopic and microscopic network levels. • We identify SEABN architecture, relevant publications, authors, subjects and journals.« less

The utility of routine histological examination of gunshot wounds.

PubMed

Perez, Danielo B; Molina, D Kimberley

2012-09-01

Determining the range of fire is a crucial part of a forensic examination of gunshot wound victims. Traditionally, this has been accomplished by noting the gross appearance of soot or powder around the wound. This study was undertaken to determine the utility of routine histological examination of gunshot wounds as related to range-of-fire determination. A prospective study was performed, and a total of 69 gunshot wounds were examined both macroscopically and microscopically. Of the 45 entrance wounds examined, there was 100% concordance between macroscopic and microscopic analysis for the close-range wounds and 67% concordance for the distant wounds, with 33% of these wounds showing no evidence of soot or powder grossly but where residue was seen microscopically. In addition, 21% of the exit wounds examined showed microscopic evidence of soot/powder residues when none were visible macroscopically. As described in previous studies, it can be assumed that the bullet itself can deposit small residues along the wound track (bullet wipe) that can be seen microscopically and is unrelated to the range of fire. Therefore, the authors conclude there is no utility in the routine histological examination of gunshot wounds for the determination of range of fire.

Comparative Evaluation of Three Methods (Microscopic Examination, Direct Fluorescent Antibody Assay, and Immunochromatographic Method) for the Diagnosis of Giardia intestinalis From Stool Specimens.

PubMed

Karadam, Senem Yaman; Ertuğ, Sema; Ertabaklar, Hatice

2016-03-01

The aim of this study was to compare direct microscopic examination, direct fluorescent antibody assay (DFA), and the immunochromatographic method (IK) and identify the best suitable method for the diagnosis of Giardia intestinalis. In this study, 25 stool samples that had been diagnosed as being infected with G. intestinalis using the native-Lugol and/or formol-ethyl acetate concentration method and 25 non-parasite-infected samples (the control group) were examined. After microscopic examination of stools, they were kept at -20°C for examination using DFA and IK. Stool samples were studied using DFA (CeLLabs, Crypto/Giardia-Cel IF) and IK (RIDA QUICK, Cryptosporidium/Giardia Combi Dipstick), as per the manufacturers' instructions. In our study, using the DFA method, parasites were detected in all 25 stool samples in which G. intestinalis was diagnosed by direct microscopic examination. Using the IK method, a particular band indicative of the parasite was detected in 24 samples. No parasites were detected in all 25 samples in the control group. Thus, when direct microscopic examination is taken as reference, the senstivity and specificity of DFA for the diagnosis of G. intestinalis were found to be 100% each, while those of IK were found to be 96% and 100%, respectively.

Use of an operating microscope during spine surgery is associated with minor increases in operating room times and no increased risk of infection

PubMed Central

Basques, Bryce A.; Golinvaux, Nicholas S.; Bohl, Daniel D.; Yacob, Alem; Toy, Jason O.; Varthi, Arya G.; Grauer, Jonathan N.

2014-01-01

Study Design Retrospective database review. Objective To evaluate whether microscope use during spine procedures is associated with increased operating room times or increased risk of infection. Summary of Background Data Operating microscopes are commonly used in spine procedures. It is debated whether the use of an operating microscope increases operating room time or confers increased risk of infection. Methods The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database, which includes data from over 370 participating hospitals, was used to identify patients undergoing elective spinal procedures with and without an operating microscope for the years 2011 and 2012. Bivariate and multivariate linear regressions were used to test the association between microscope use and operating room times. Bivariate and multivariate logistic regressions were similarly conducted to test the association between microscope use and infection occurrence within 30 days of surgery. Results A total of 23,670 elective spine procedures were identified, of which 2,226 (9.4%) used an operating microscope. The average patient age was 55.1 ± 14.4 years. The average operative time (incision to closure) was 125.7 ± 82.0 minutes. Microscope use was associated with minor increases in preoperative room time (+2.9 minutes, p=0.013), operative time (+13.2 minutes, p<0.001), and total room time (+18.6 minutes, p<0.001) on multivariate analysis. A total of 328 (1.4%) patients had an infection within 30 days of surgery. Multivariate analysis revealed no significant difference between the microscope and non-microscope groups for occurrence of any infection, superficial surgical site infection (SSI), deep SSI, organ space infection, or sepsis/septic shock, regardless of surgery type. Conclusions We did not find operating room times or infection risk to be significant deterrents for use of an operating microscope during spine surgery. PMID:25188600

Study of factors affecting the appearance of colors under microscopes

NASA Astrophysics Data System (ADS)

Zakizadeh, Roshanak; Martinez-Garcia, Juan; Raja, Kiran B.; Siakidis, Christos

2013-11-01

The variation of colors in microscopy systems can be quite critical for some users. To address this problem, a study is conducted to analyze how different factors such as size of the sample, intensity of the microscope's light source and the characteristics of the material like chroma and saturation can affect the color appearance through the eyepiece of the microscope. To study the changes in colors considering these factors, the spectral reflectance of 24 colors of GretagMacbeth Classic ColorChecker® and Mini ColorChecker® which are placed under a Nikon ECLIPSE MA200 microscope®2 using dark filed and bright field illuminations which result in different intensity levels, is measured using a spectroradiometer®3 which was placed in front of the eyepiece of the microscope. The results are compared with the original data from N. Ohta1. The evaluation is done by observing the shift in colors in the CIE 1931 Chromaticity Diagram and the CIELAB space, also by applying a wide set of color-difference formulas, namely: CIELAB, CMC, BFD, CIE94, CIEDE2000, DIN99d and DIN99b. Furthermore, to emphasize on the color regions in which the highest difference is observed, the authors have obtained the results from another microscope; Olympus SZX10®4, which in this case the measurement is done by mounting the spectroradiometer to the camera port of the microscope. The experiment leads to some interesting results, among which is the consistency in the highest difference observed considering different factors or how the change in saturation of the samples of the same hue can affect the results.

Microscopic colitis syndrome.

PubMed Central

Veress, B; Löfberg, R; Bergman, L

1995-01-01

The colorectal biopsy specimens from 30 patients with chronic watery diarrhoea but normal endoscopic and radiographic findings were studied by light microscopy, morphometry, immunohistochemistry, and two patients with electron microscopy. The histological changes in the colorectum were originally diagnosed in six patients as lymphocytic colitis and in 24 patients as collagenous colitis. The analysis of the specimens for this study could delineate three distinct groups of microscopic colitis: lymphocytic colitis (six patients), collagenous colitis without lymphocytic attack on the surface epithelium (seven patients), and a mixed form presenting with both thickening of the collagen plate and increased number of intraepithelial lymphocytes (17 patients). No transformation was seen from one type to another during follow up of six patients for four to seven years. Increased numbers of active pericryptal myofibroblasts were found with the electron microscope in one patient with mixed microscopic colitis showing also myofibroblasts entrapped within the collagen layer. Hitherto undescribed flat mucosa of the ileum was found in one patient with lymphocytic colitis and both flat mucosa and thickening of the collagen plate in the ileum were seen in one patient with the mixed form of the disease. In another patient with mixed microscopic colitis, normalisation of the colorectal morphology occurred after temporary loop ileostomy, followed by the reappearance of both diarrhoea, inflammation, and thickening of the collagen plate after the ileostomy was reversed. No association was found between non-steroid anti-inflammatory drug (NSAID) consumption and collagenous or mixed microscopic colitis. The primary cause of microscopic colitis is probably an immunological reaction to luminal antigen/s, perhaps of ileal origin. The engagement of the pericryptal myofibroblasts in the disease process might result in the development of the various forms of microscopic colitis. An inverse relation between intraepithelial lymphocyte count and collagen thickness may indicate that microscopic colitis is a spectral disease. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:7615277

Evaluation of a Mobile Phone-Based Microscope for Screening of Schistosoma haematobium Infection in Rural Ghana.

PubMed

Bogoch, Isaac I; Koydemir, Hatice C; Tseng, Derek; Ephraim, Richard K D; Duah, Evans; Tee, Joseph; Andrews, Jason R; Ozcan, Aydogan

2017-06-01

AbstractSchistosomiasis affects over 170 million people in Africa. Here we compare a novel, low-cost mobile phone microscope to a conventional light microscope for the label-free diagnosis of Schistosoma haematobium infections in a rural Ghanaian school setting. We tested the performance of our handheld microscope using 60 slides that were randomly chosen from an ongoing epidemiologic study in school-aged children. The mobile phone microscope had a sensitivity of 72.1% (95% confidence interval [CI]: 56.1-84.2), specificity of 100% (95% CI: 75.9-100), positive predictive value of 100% (95% CI: 86.3-100), and a negative predictive value of 57.1% (95% CI: 37.4-75.0). With its modest sensitivity and high specificity, this handheld and cost-effective mobile phone-based microscope is a stepping-stone toward developing a powerful tool in clinical and public health settings where there is limited access to conventional laboratory diagnostic support.

The effect of intermediate-scale motions on line formation. [sawtooth and sine motions in solar atmosphere

NASA Technical Reports Server (NTRS)

Shine, R. A.

1975-01-01

The problem of LTE and non-LTE line formation in the presence of nonthermal velocity fields with geometric scales between the microscopic and macroscopic limits is investigated in the cases of periodic sinusoidal and sawtooth waves. For a fixed source function (the LTE case), it is shown that time-averaged line profiles progress smoothly from the microscopic to the macroscopic limits as the geometric scale of the motions increases, that the sinusoidal motions produce symmetric time-averaged profiles, and that the sawtooth motions cause a redshift. In several idealized non-LTE cases, it is found that intermediate-scale velocity fields can significantly increase the surface source functions and line-core intensities. Calculations are made for a two-level atom in an isothermal atmosphere for a range of velocity scales and non-LTE coupling parameters and also for a two-level atom and a four-level representation of Na I line formation in the Harvard-Smithsonian Reference Atmosphere (1971) solar model. It is found that intermediate-scale velocity fields in the solar atmosphere could explain the central intensities of the Na I D lines and other strong absorption lines without invoking previously suggested high electron densities.

Mechanically modulated dewetting by atomic force microscope for micro- and nano- droplet array fabrication.

PubMed

Wang, Feifei; Li, Pan; Wang, Dong; Li, Longhai; Xie, Shuangxi; Liu, Lianqing; Wang, Yuechao; Li, Wen Jung

2014-10-06

Organizing a material into well-defined patterns during the dewetting process provides an attractive micro-/nano-fabrication method without using a conventional lithographic process, and hence, offers potential applications in organic electronics, optics systems, and memory devices. We report here how the mechanical modification of polymer surface by an Atomic Force Microscope (AFM) can be used to guide thin film dewetting evolution and break the intrinsic spatial correlation of spontaneous instability. An AFM is used to implement the mechanical modification of progressively narrow grids to investigate the influence of pattern size on the modulation of ultrathin polystyrene films dewetting evolution. For films with different initial thicknesses, when grid size is close to or below the characteristic wavelength of instability, the spinodal dewetting is suppressed, and film rupture is restricted to the cutting trench. We will show in this paper it is possible to generate only one droplet per gridded area on a thin film subsequent to nucleation dominated dewetting on a non-patterned substrate. Furthermore, when the grid periodicity exceeds the spinodal length, the number of droplets in predefined areas gradually approaches that associated with unconfined dewetting.

Mechanically Modulated Dewetting by Atomic Force Microscope for Micro- and Nano- Droplet Array Fabrication

PubMed Central

Wang, Feifei; Li, Pan; Wang, Dong; Li, Longhai; Xie, Shuangxi; Liu, Lianqing; Wang, Yuechao; Li, Wen Jung

2014-01-01

Organizing a material into well-defined patterns during the dewetting process provides an attractive micro-/nano-fabrication method without using a conventional lithographic process, and hence, offers potential applications in organic electronics, optics systems, and memory devices. We report here how the mechanical modification of polymer surface by an Atomic Force Microscope (AFM) can be used to guide thin film dewetting evolution and break the intrinsic spatial correlation of spontaneous instability. An AFM is used to implement the mechanical modification of progressively narrow grids to investigate the influence of pattern size on the modulation of ultrathin polystyrene films dewetting evolution. For films with different initial thicknesses, when grid size is close to or below the characteristic wavelength of instability, the spinodal dewetting is suppressed, and film rupture is restricted to the cutting trench. We will show in this paper it is possible to generate only one droplet per gridded area on a thin film subsequent to nucleation dominated dewetting on a non-patterned substrate. Furthermore, when the grid periodicity exceeds the spinodal length, the number of droplets in predefined areas gradually approaches that associated with unconfined dewetting. PMID:25283744

A case of generalized argyria after ingestion of colloidal silver solution.

PubMed

Kim, Yangho; Suh, Ho Seok; Cha, Hee Jeong; Kim, Suk Hwan; Jeong, Kyoung Sook; Kim, Dong Hoon

2009-03-01

A 58-year-old woman was referred to our hospital due to progressive skin darkening, which began 5 months previously. The patient had strikingly diffuse blue-gray discoloration of the skin, most prominent in sun-exposed areas, especially her face and hands. The oral mucosa, tongue, gums, eye conjunctiva, ears, nail beds, and trunk were also involved. Bluish-gray discoloration of all nails was aggravated by cold weather. She had ingested 1 L of colloidal silver solution daily for approximately 16 months as a traditional remedy. Her serum silver concentration was 381 ng/ml which was a very high (reference level: <15 ng/ml). Light microscopic examination of a punch biopsy specimen from her nose revealed fine, minute, round, and brown-black granules deposited in the basement membrane of hair follicular epithelium. Scanning electron microscopic examination showed electron-dense granules deposited in the intercellular space of sweat glands. Energy disperse X-ray spectrometry analysis demonstrated peaks for silver and sulfur in the dense black deposits. The ingestion of colloidal silver appears to be an increasing practice among patients using alternative health practices. All silver-containing products including colloidal silver should be labeled with a clear warning to prevent argyria, especially in alternative health practices.

On the Progress of Scanning Transmission Electron Microscopy (STEM) Imaging in a Scanning Electron Microscope.

PubMed

Sun, Cheng; Müller, Erich; Meffert, Matthias; Gerthsen, Dagmar

2018-04-01

Transmission electron microscopy (TEM) with low-energy electrons has been recognized as an important addition to the family of electron microscopies as it may avoid knock-on damage and increase the contrast of weakly scattering objects. Scanning electron microscopes (SEMs) are well suited for low-energy electron microscopy with maximum electron energies of 30 keV, but they are mainly used for topography imaging of bulk samples. Implementation of a scanning transmission electron microscopy (STEM) detector and a charge-coupled-device camera for the acquisition of on-axis transmission electron diffraction (TED) patterns, in combination with recent resolution improvements, make SEMs highly interesting for structure analysis of some electron-transparent specimens which are traditionally investigated by TEM. A new aspect is correlative SEM, STEM, and TED imaging from the same specimen region in a SEM which leads to a wealth of information. Simultaneous image acquisition gives information on surface topography, inner structure including crystal defects and qualitative material contrast. Lattice-fringe resolution is obtained in bright-field STEM imaging. The benefits of correlative SEM/STEM/TED imaging in a SEM are exemplified by structure analyses from representative sample classes such as nanoparticulates and bulk materials.

Removal of anti-Stokes emission background in STED microscopy by FPGA-based synchronous detection

NASA Astrophysics Data System (ADS)

Castello, M.; Tortarolo, G.; Coto Hernández, I.; Deguchi, T.; Diaspro, A.; Vicidomini, G.

2017-05-01

In stimulated emission depletion (STED) microscopy, the role of the STED beam is to de-excite, via stimulated emission, the fluorophores that have been previously excited by the excitation beam. This condition, together with specific beam intensity distributions, allows obtaining true sub-diffraction spatial resolution images. However, if the STED beam has a non-negligible probability to excite the fluorophores, a strong fluorescent background signal (anti-Stokes emission) reduces the effective resolution. For STED scanning microscopy, different synchronous detection methods have been proposed to remove this anti-Stokes emission background and recover the resolution. However, every method works only for a specific STED microscopy implementation. Here we present a user-friendly synchronous detection method compatible with any STED scanning microscope. It exploits a data acquisition (DAQ) card based on a field-programmable gate array (FPGA), which is progressively used in STED microscopy. In essence, the FPGA-based DAQ card synchronizes the fluorescent signal registration, the beam deflection, and the excitation beam interruption, providing a fully automatic pixel-by-pixel synchronous detection method. We validate the proposed method in both continuous wave and pulsed STED microscope systems.

Chronic traumatic encephalopathy.

PubMed

Omalu, Bennet

2014-01-01

Chronic traumatic encephalopathy (CTE) is a progressive neurodegenerative syndrome, which is caused by single, episodic, or repetitive blunt force impacts to the head and transfer of acceleration-deceleration forces to the brain. CTE presents clinically as a composite syndrome of mood disorders and behavioral and cognitive impairment, with or without sensorimotor impairment. Symptoms of CTE may begin with persistent symptoms of acute traumatic brain injury (TBI) following a documented episode of brain trauma or after a latent period that may range from days to weeks to months and years, up to 40 years following a documented episode of brain trauma or cessation of repetitive TBI. Posttraumatic encephalopathy is distinct from CTE, can be comorbid with CTE, and is a clinicopathologic syndrome induced by focal and/or diffuse, gross and/or microscopic destruction of brain tissue following brain trauma. The brain of a CTE sufferer may appear grossly unremarkable, but shows microscopic evidence of primary and secondary proteinopathies. The primary proteinopathy of CTE is tauopathy, while secondary proteinopathies may include, but are not limited to, amyloidopathy and TDP proteinopathy. Reported prevalence rates of CTE in cohorts exposed to TBI ranges from 3 to 80% across age groups. © 2014 S. Karger AG, Basel.

[Comparison of morphological and microscopical diagnostic characters of Hawthorn fruits (Crataegus species)].

PubMed

Gao, G Y; Feng, Y X

1995-01-01

This paper deals with studies on morphological and microscopical diagnostic characters of Chinese Hawthorn fruits. Their similarities and differences in morphological and microscopical characters among eight species of Crataegus (C. pinnatifida Bge., C. pinnatifida var. major NE Br., C. cuneata sieb. & Zuce., C. scabrifolia (Franch.) Rehd., C. hupehensis Sarg., C. kansuensis Wils, C. maximowiczii Schneid. and C. sanguinea Pall.) fruits are compared and illustrated with diagrams.

Scanning SQUID microscope with an in-situ magnetization/demagnetization field for geological samples

NASA Astrophysics Data System (ADS)

Du, Junwei; Liu, Xiaohong; Qin, Huafeng; Wei, Zhao; Kong, Xiangyang; Liu, Qingsong; Song, Tao

2018-04-01

Magnetic properties of rocks are crucial for paleo-, rock-, environmental-magnetism, and magnetic material sciences. Conventional rock magnetometers deal with bulk properties of samples, whereas scanning microscope can map the distribution of remanent magnetization. In this study, a new scanning microscope based on a low-temperature DC superconducting quantum interference device (SQUID) equipped with an in-situ magnetization/demagnetization device was developed. To realize the combination of sensitive instrument as SQUID with high magnetizing/demagnetizing fields, the pick-up coil, the magnetization/demagnetization coils and the measurement mode of the system were optimized. The new microscope has a field sensitivity of 250 pT/√Hz at a coil-to-sample spacing of ∼350 μm, and high magnetization (0-1 T)/ demagnetization (0-300 mT, 400 Hz) functions. With this microscope, isothermal remanent magnetization (IRM) acquisition and the according alternating field (AF) demagnetization curves can be obtained for each point without transferring samples between different procedures, which could result in position deviation, waste of time, and other interferences. The newly-designed SQUID microscope, thus, can be used to investigate the rock magnetic properties of samples at a micro-area scale, and has a great potential to be an efficient tool in paleomagnetism, rock magnetism, and magnetic material studies.

21 CFR 884.6190 - Assisted reproductive microscopes and microscope accessories.

Code of Federal Regulations, 2010 CFR

2010-04-01

... contrast microscopes, dissecting microscopes and inverted stage microscopes. (b) Classification. Class I... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproductive microscopes and microscope... Devices § 884.6190 Assisted reproductive microscopes and microscope accessories. (a) Identification...

Ultrastructural Study of Some Pollen Grains of Prairie Flowers

ERIC Educational Resources Information Center

Kozar, Frank

1973-01-01

Discusses the importance of the electron microscope, and in particular the scanning electron microscope, in studying the surface topography, sectional substructures, and patterns of development of pollen grains. The production, dispersal methods, and structure of pollen grains are described and illustrated with numerous electron micrographs. (JR)

Surgical Results of Pure Endoscopic Endonasal Transsphenoidal Surgery for 331 Pituitary Adenomas: A 15-Year Experience from a Single Institution.

PubMed

Jang, Ji Hwan; Kim, Kyu Hong; Lee, Young Min; Kim, Joon Soo; Kim, Young Zoon

2016-12-01

The aim of this study is to report the results of pure endoscopic endonasal transsphenoidal surgery (EETSS) for pituitary adenomas (PAs) and to evaluate the efficacy and safety of this procedure. In addition, we tried to determine the predicting factors for progression of PAs. We reviewed the medical records of 331 consecutive patients who underwent pure EETSS of newly diagnosed PAs between April 1998 and December 2014. Demographic, endocrinologic, and radiologic features and their outcomes, complications, and hospital stay durations were retrospectively assessed in these patients. There were 157 (47.4%) nonfunctioning adenomas and 174 (52.6%) hormone-secreting adenomas. Fifty-one (15.4%) complications were present in 39 patients postoperatively. The frequent complications were temporary and permanent diabetes insipidus (14 and 3 cases, respectively), syndrome of inappropriate antidiuretic hormone secretion (9 cases), and cerebrospinal fluid leaks (6 cases). There was only 1 death (0.3%) related to the procedure in this series. The patient's age (P = 0.047), the tumor size (P = 0.003), and the parasellar growth (P <0.001) were associated with the occurrence of complications on multivariate analysis. Progression occurred in 92 (27.8%) patients and the mean time-to-progression was 23.7 months (range, 3.7-52.4 months) after a mean follow-up period of 68.5 months. In the multivariate analysis, the tumor size (P = 0.021), the extent of surgery (P = 0.012), the Knosp classification (P = 0.002), and the MIB-1 index (P = 0.019) were associated with progression-free survival. The mean duration of hospitalization was 4.4 (±1.6) days. The pure EETSS of PA provides acceptable and reasonable results representing a safe alternative procedure to the traditional transsphenoidal microscopic approach. Copyright © 2016 Elsevier Inc. All rights reserved.

Smartphone adapters for digital photomicrography.

PubMed

Roy, Somak; Pantanowitz, Liron; Amin, Milon; Seethala, Raja R; Ishtiaque, Ahmed; Yousem, Samuel A; Parwani, Anil V; Cucoranu, Ioan; Hartman, Douglas J

2014-01-01

Photomicrographs in Anatomic Pathology provide a means of quickly sharing information from a glass slide for consultation, education, documentation and publication. While static image acquisition historically involved the use of a permanently mounted camera unit on a microscope, such cameras may be expensive, need to be connected to a computer, and often require proprietary software to acquire and process images. Another novel approach for capturing digital microscopic images is to use smartphones coupled with the eyepiece of a microscope. Recently, several smartphone adapters have emerged that allow users to attach mobile phones to the microscope. The aim of this study was to test the utility of these various smartphone adapters. We surveyed the market for adapters to attach smartphones to the ocular lens of a conventional light microscope. Three adapters (Magnifi, Skylight and Snapzoom) were tested. We assessed the designs of these adapters and their effectiveness at acquiring static microscopic digital images. All adapters facilitated the acquisition of digital microscopic images with a smartphone. The optimal adapter was dependent on the type of phone used. The Magnifi adapters for iPhone were incompatible when using a protective case. The Snapzoom adapter was easiest to use with iPhones and other smartphones even with protective cases. Smartphone adapters are inexpensive and easy to use for acquiring digital microscopic images. However, they require some adjustment by the user in order to optimize focus and obtain good quality images. Smartphone microscope adapters provide an economically feasible method of acquiring and sharing digital pathology photomicrographs.

Intraocular Gnathostoma spinigerum. Clinicopathologic study of two cases with review of literature.

PubMed

Biswas, J; Gopal, L; Sharma, T; Badrinath, S S

1994-01-01

Live intraocular nematode is a rare occurrence that is mostly reported in Southeast Asian countries. Common nematodes that are seen live in the eye are microfilaria, Gnathostoma, and Angiostrongylus. Approximately 12 cases of intraocular gnathostomiasis have been reported in the literature. Two cases of intraocular gnathostoma, removed by vitrectomy in the first case and by paracentesis in the second case, are reported. Morphologic study of the parasites in wet preparation was performed under dissecting microscope and fixed in Karnovosky's fixative. Light microscopic and scanning electron microscopic studies were also performed. The first patient had anterior uveitis, multiple iris holes, and dense vitreous haze with fibrous proliferation over the optic disc. On resolution of the vitreous haze, a live worm was seen in the vitreous cavity. The second patient had anterior uveitis with secondary glaucoma, multiple iris holes, mild vitritis, and focal subretinal haemorrhage with subretinal tracts. Four days later a live worm was seen in the anterior chamber and removed. Microscopic study of the parasites from both patients revealed typical head bulb with four circumferential rows of hooklets, and fine cuticular spines were seen on the surface of the body. Iris holes, uveitis, and subretinal haemorrhage with subretinal tract can be characteristic features of intraocular gnathostomiasis. Identification of this parasite can be made by typical features, which can be identified on light and scanning electron microscopic study.

The Behavior of Matter under Nonequilibrium Conditions: Fundamental Aspects and Applications: Progress Report for Period August 15, 1989 - April 14, 1990

DOE R&D Accomplishments Database

Prigogine, I.

1989-10-01

As in the previous period, our work has been concerned with the study of the properties of nonequilibrium systems and especially with the mechanism of self-organization. As is well-known, the study of self-organization began with the investigation of hydrodynamical or chemical instabilities studied from the point of view of macroscopic physics. The main outcome is that nonequilibrium generates spatial correlations of macroscopic physics. The main outcome is that nonequilibrium generated spatial correlations of macroscopic range whose characteristics length is an intrinsic property and whose amplitude is determined by nonequilibrium constraints. A survey of the macroscopic approach to nonequilibrium states is given in the paper. "Nonequilibrium States and Long Range Correlations in Chemical Dynamics", by G. Nicolis at al. However, over the last few years important progress has been made in the simulation of nonequilibrium situations using mainly molecular dynamics. It appears now that processes corresponding to self-organization as well as the appearance of long-range correlations can be obtained in this way starting from a program involving Newtonian dynamics (generally the laws of interaction correspond to hard spheres or hard disks). Examples of such types of studies leading to Benard instabilities, to chemical clocks, or to spatial structure formation are given in this report. As a result, we may now view self-organization as a direct expression of tan appropriate microscopic dynamics. This is the reason why we have devoted much work to the study of large Poincare systems (LPS) involving continuous sets of resonances. These systems have been shown to lead, according to the constraints, either to equilibrium situations or to nonequilibrium states involving long range correlations. We discuss LPS in the frame of classical mechanics.

Titin domains progressively unfolded by force are homogenously distributed along the molecule.

PubMed

Bianco, Pasquale; Mártonfalvi, Zsolt; Naftz, Katalin; Kőszegi, Dorina; Kellermayer, Miklós

2015-07-21

Titin is a giant filamentous protein of the muscle sarcomere in which stretch induces the unfolding of its globular domains. However, the mechanisms of how domains are progressively selected for unfolding and which domains eventually unfold have for long been elusive. Based on force-clamp optical tweezers experiments we report here that, in a paradoxical violation of mechanically driven activation kinetics, neither the global domain unfolding rate, nor the folded-state lifetime distributions of full-length titin are sensitive to force. This paradox is reconciled by a gradient of mechanical stability so that domains are gradually selected for unfolding as the magnitude of the force field increases. Atomic force microscopic screening of extended titin molecules revealed that the unfolded domains are distributed homogenously along the entire length of titin, and this homogeneity is maintained with increasing overstretch. Although the unfolding of domains with progressively increasing mechanical stability makes titin a variable viscosity damper, the spatially randomized variation of domain stability ensures that the induced structural changes are not localized but are distributed along the molecule's length. Titin may thereby provide complex safety mechanims for protecting the sarcomere against structural disintegration under excessive mechanical conditions. Copyright © 2015 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Soft x-ray imaging with incoherent sources

NASA Astrophysics Data System (ADS)

Wachulak, P.; Torrisi, A.; Ayele, M.; Bartnik, A.; Czwartos, J.; Wegrzyński, Ł.; Fok, T.; Parkman, T.; Vondrová, Š.; Turnová, J.; Odstrcil, M.; Fiedorowicz, H.

2017-05-01

In this work we present experimental, compact desk-top SXR microscope, the EUV microscope which is at this stage a technology demonstrator, and finally, the SXR contact microscope. The systems are based on laser-plasma EUV and SXR sources, employing a double stream gas puff target. The EUV and SXR full field microscopes, operating at 13.8 nm and 2.88 nm wavelengths, respectively, are capable of imaging nanostructures with a sub-50 nm spatial resolution with relatively short (seconds) exposure times. The SXR contact microscope operates in the "water-window" spectral range, to produce an imprint of the internal structure of the sample in a thin layer of SXR light sensitive photoresist. Applications of such desk-top EUV and SXR microscopes for studies of variety of different samples - test objects for resolution assessment and other objects such as carbon membranes, DNA plasmid samples, organic and inorganic thin layers, diatoms, algae and carcinoma cells, are also presented. Details about the sources, the microscopes as well as the imaging results for various objects will be presented and discussed. The development of such compact imaging systems may be important to the new research related to biological, material science and nanotechnology applications.

SIL-STED microscopy technique enhancing super-resolution of fluorescence microscopy

NASA Astrophysics Data System (ADS)

Park, No-Cheol; Lim, Geon; Lee, Won-sup; Moon, Hyungbae; Choi, Guk-Jong; Park, Young-Pil

2017-08-01

We have characterized a new type STED microscope which combines a high numerical aperture (NA) optical head with a solid immersion lens (SIL), and we call it as SIL-STED microscope. The advantage of a SIL-STED microscope is that its high NA of the SIL makes it superior to a general STED microscope in lateral resolution, thus overcoming the optical diffraction limit at the macromolecular level and enabling advanced super-resolution imaging of cell surface or cell membrane structure and function Do. This study presents the first implementation of higher NA illumination in a STED microscope limiting the fluorescence lateral resolution to about 40 nm. The refractive index of the SIL which is made of material KTaO3 is about 2.23 and 2.20 at a wavelength of 633 nm and 780 nm which are used for excitation and depletion in STED imaging, respectively. Based on the vector diffraction theory, the electric field focused by the SILSTED microscope is numerically calculated so that the numerical results of the point dispersion function of the microscope and the expected resolution could be analyzed. For further investigation, fluorescence imaging of nano size fluorescent beads is fulfilled to show improved performance of the technique.

Loupe magnification for small incision cataract surgery--an alternative to microscope magnification?

PubMed

Singh, S K; Winter, I; Hennig, A

2008-01-01

A Prospective randomized controlled study was conducted to compare outcome of Small Incision Cataract Surgery (SICS) using microscope or loupe magnification. Two hundred fifty one patient with mature cataract were randomly allocated to SICS-Fishhook Technique with either microscope (127 eyes) or loupe (124 eyes) magnification. Intra- and postoperative complications and immediate visual outcome were analyzed. Nearly two third (microscope 65% and magnifying loupe 62.9%) of all patients had good visual outcome on first postoperative day. Poor outcome (<6/60) was recorded in 8% (microscope group) and 7% (magnifying loupe group). Mean visual acuity with Snellen was 0.39 (SD 0.2) in microscope group and 0.38 (SD 0.2) in magnifying loupe group. Intra operative complications were comparable in both groups. Mean surgery time with loupe magnification was significantly shorter. Comparatively equivalent good surgical outcome was achieved with loupe as well as with microscope magnification. However performing SICS with loupe magnification is significantly faster. Small incision cataract surgery with loupe magnification is safe and effective procedure for cataract surgery so it can play a role in reducing cataract blindness in developing countries of the world.

Microscopic theory of linear light scattering from mesoscopic media and in near-field optics.

PubMed

Keller, Ole

2005-08-01

On the basis of quantum mechanical response theory a microscopic propagator theory of linear light scattering from mesoscopic systems is presented. The central integral equation problem is transferred to a matrix equation problem by discretization in transitions between pairs of (many-body) energy eigenstates. The local-field calculation which appears from this approach is valid down to the microscopic region. Previous theories based on the (macroscopic) dielectric constant concept make use of spatial (geometrical) discretization and cannot in general be trusted on the mesoscopic length scale. The present theory can be applied to light scattering studies in near-field optics. After a brief discussion of the macroscopic integral equation problem a microscopic potential description of the scattering process is established. In combination with the use of microscopic electromagnetic propagators the formalism allows one to make contact to the macroscopic theory of light scattering and to the spatial photon localization problem. The quantum structure of the microscopic conductivity response tensor enables one to establish a clear physical picture of the origin of local-field phenomena in mesoscopic and near-field optics. The Huygens scalar propagator formalism is revisited and its generality in microscopic physics pointed out.

Spine surgeon's kinematics during discectomy, part II: operating table height and visualization methods, including microscope.

PubMed

Park, Jeong Yoon; Kim, Kyung Hyun; Kuh, Sung Uk; Chin, Dong Kyu; Kim, Keun Su; Cho, Yong Eun

2014-05-01

Surgeon spine angle during surgery was studied ergonomically and the kinematics of the surgeon's spine was related with musculoskeletal fatigue and pain. Spine angles varied depending on operation table height and visualization method, and in a previous paper we showed that the use of a loupe and a table height at the midpoint between the umbilicus and the sternum are optimal for reducing musculoskeletal loading. However, no studies have previously included a microscope as a possible visualization method. The objective of this study is to assess differences in surgeon spine angles depending on operating table height and visualization method, including microscope. We enrolled 18 experienced spine surgeons for this study, who each performed a discectomy using a spine surgery simulator. Three different methods were used to visualize the surgical field (naked eye, loupe, microscope) and three different operating table heights (anterior superior iliac spine, umbilicus, the midpoint between the umbilicus and the sternum) were studied. Whole spine angles were compared for three different views during the discectomy simulation: midline, ipsilateral, and contralateral. A 16-camera optoelectronic motion analysis system was used, and 16 markers were placed from the head to the pelvis. Lumbar lordosis, thoracic kyphosis, cervical lordosis, and occipital angle were compared between the different operating table heights and visualization methods as well as a natural standing position. Whole spine angles differed significantly depending on visualization method. All parameters were closer to natural standing values when discectomy was performed with a microscope, and there were no differences between the naked eye and the loupe. Whole spine angles were also found to differ from the natural standing position depending on operating table height, and became closer to natural standing position values as the operating table height increased, independent of the visualization method. When using a microscope, lumbar lordosis, thoracic kyphosis, and cervical lordosis showed no differences according to table heights above the umbilicus. This study suggests that the use of a microscope and a table height above the umbilicus are optimal for reducing surgeon musculoskeletal fatigue.

Influence of mechanical noise inside a scanning electron microscope.

PubMed

de Faria, Marcelo Gaudenzi; Haddab, Yassine; Le Gorrec, Yann; Lutz, Philippe

2015-04-01

The scanning electron microscope is becoming a popular tool to perform tasks that require positioning, manipulation, characterization, and assembly of micro-components. However, some of these applications require a higher level of performance with respect to dynamics and precision of positioning. One limiting factor is the presence of unidentified noises and disturbances. This work aims to study the influence of mechanical disturbances generated by the environment and by the microscope, identifying how these can affect elements in the vacuum chamber. To achieve this objective, a dedicated setup, including a high-resolution vibrometer, was built inside the microscope. This work led to the identification and quantification of main disturbances and noise sources acting on a scanning electron microscope. Furthermore, the effects of external acoustic excitations were analysed. Potential applications of these results include noise compensation and real-time control for high accuracy tasks.

SORPTION OF LEAD ON A HIGH AFFINITY OXIDE: MACROSCOPIC AND MICROSCOPIC STUDIES

EPA Science Inventory

Sorption of lead (Pb) was investigated on an innovative metal oxide compound using macroscopic and microscopic techniques. The objective of this study was to elucidate the sorption mechanism of Pb on the high-affinity engineered oxide with time at pH 6 employing batch methods an...

SORPTION OF LEAD ON A HIGH AFFINITY OXIDE: MACROSCOPIC AND MICROSCOPIC STUDIES (ABSTRACT)

EPA Science Inventory

Sorption of lead (Pb) was investigated on an innovative metal oxide compound using macroscopic and microscopic techniques. The objective of this study was to elucidate the sorption mechanism of Pb on the high-affinity engineered oxide with time at pH 6 employing batch methods an...

Image Analysis, Microscopic, and Spectrochemical Study of the PVC Dry Blending Process,

DTIC Science & Technology

The dry blending process used in the production of electrical grade pvc formulations has been studies using a combination of image analysis , microscopic...by image analysis techniques. Optical and scanning electron microscopy were used to assess morphological differences. Spectrochemical techniques were used to indicate chemical changes.

Fast and Adaptive Auto-focusing Microscope

NASA Astrophysics Data System (ADS)

Obara, Takeshi; Igarashi, Yasunobu; Hashimoto, Koichi

Optical microscopes are widely used in biological and medical researches. By using the microscope, we can observe cellular movements including intracellular ions and molecules tagged with fluorescent dyes at a high magnification. However, a freely motile cell easily escapes from a 3D field of view of the typical microscope. Therefore, we propose a novel auto-focusing algorithm and develop a auto-focusing and tracking microscope. XYZ positions of a microscopic stage are feedback controlled to focus and track the cell automatically. A bright-field image is used to estimate a cellular position. XY centroids are used to estimate XY positions of the tracked cell. To estimate Z position, we use a diffraction pattern around the cell membrane. This estimation method is so-called Depth from Diffraction (DFDi). However, this method is not robust for individual differences between cells because the diffraction pattern depends on each cellular shape. Therefore, in this study, we propose a real-time correction of DFDi by using 2D Laplacian of an intracellular area as a goodness of the focus. To evaluate the performance of our developed algorithm and microscope, we auto-focus and track a freely moving paramecium. In this experimental result, the paramecium is auto-focused and kept inside the scope of the microscope during 45s. The evaluated focal error is within 5µm, while a length and a thickness of the paramecium are about 200µm and 50µm, respectively.

Effect of homogenization on the properties and microstructure of Mozzarella cheese from buffalo milk.

PubMed

Abd El-Gawad, Mona A M; Ahmed, Nawal S; El-Abd, M M; Abd El-Rafee, S

2012-04-02

The name pasta filata refers to a unique plasticizing and texturing treatments of the fresh curd in hot water that imparts to the finished cheese its characteristic fibrous structure and melting properties. Mozzarella cheese made from standardized homogenized and non-homogenized buffalo milk with 3 and 1.5%fat. The effect of homogenization on rheological, microstructure and sensory evaluation was carried out. Fresh raw buffalo milk and starter cultures of Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus were used. The coagulants were calf rennet powder (HA-LA). Standardized buffalo milk was homogenized at 25 kg/cm2 pressure after heating to 60°C using homogenizer. Milk and cheese were analysed. Microstructure of the cheese samples was investigated either with an application of transmission or scanning electron microscope. Statistical analyses were applied on the obtained data. Soluble nitrogen total volatile free fatty acids, soluble tyrosine and tryptophan increased with using homogenized milk and also, increased with relatively decrease in case of homogenized Mozzarella cheese. Meltability of Mozzarella cheese increased with increasing the fat content and storage period and decrease with homogenization. Mozzarella cheese firmness increased with homogenization and also, increased with progressing of storage period. Flavour score, appearance and total score of Mozzarella cheese increased with homogenization and storage period progress, while body and texture score decreased with homogenization and increased with storage period progress. Microstructure of Mozzarella cheese showed the low fat cheese tends to be harder, more crumbly and less smooth than normal. Curd granule junctions were prominent in non-homogenized milk cheese. Homogenization of milk cheese caused changes in the microstructure of the Mozzarella cheese. Microstructure studies of cheese revealed that cheese made from homogenized milk is smoother and has a finer texture than non-homogenized but is also, firmer and more elastic.

Is oxygen availability a limiting factor for in vitro folliculogenesis?

PubMed Central

Sudhakaran, Sam; Barbato, Vincenza; Merolla, Anna; Braun, Sabrina; Di Nardo, Maddalena; Costanzo, Valentina; Ferraro, Raffaele; Iannantuoni, Nicola

2018-01-01

Transplantation of ovarian tissue for the preservation of fertility in oncological patients is becoming an accepted clinical practice. However, the risk of re-introducing tumour cells at transplantation has stirred an increased interest for complete in vitro folliculogenesis. This has not yet been achieved in humans possibly for the lack of knowledge on the environmental milieu that orchestrates folliculogenesis in vivo. The main aim of this study was to investigate the effect of oxygen availability on follicle health and growth during in vitro culture of ovarian tissue strips. To this end, a model was developed to predict the dissolved oxygen concentration in tissue under varying culture conditions. Ovarian cortical strips of bovine, adopted as an animal model, and human tissue were cultured in conventional (CD) and gas permeable (PD) dishes under different media column heights and gaseous oxygen tensions for 3, 6 and 9 days. Follicle quality, activation of primordial follicles to the primary stage, and progression to the secondary stage were analysed through histology. Follicle viability was assessed through a live-dead assay at the confocal scanning laser microscope. Findings showed a higher follicle quality and viability after culture of bovine ovarian strips in PD in adequate medium height and oxygen tensions. The best culture conditions found in the bovine were adopted for human ovarian strip culture and promoted a higher follicle quality, viability and progression. Overall, data demonstrated that modulation of oxygen availability in tissue plays a key role in maintaining follicles’ health and their ability to survive and progress to the secondary stage during ovarian tissue in vitro culture. Such culture conditions could increase the yield of healthy secondary follicles for subsequent dissection and individual culture to obtain competent oocytes. PMID:29425251

Progression of Pro23His Retinopathy in a Miniature Swine Model of Retinitis Pigmentosa

PubMed Central

Scott, Patrick A.; de Castro, Juan P. Fernandez; DeMarco, Paul J.; Ross, Jason W.; Njoka, Josephat; Walters, Eric; Prather, Randall S.; McCall, Maureen A.; Kaplan, Henry J.

2017-01-01

Purpose We characterize the progression of retinopathy in Filial 1 (F1) progeny of a transgenic (Tg) founder miniswine exhibiting severe Pro23His (P23H) retinopathy. Methods The F1 TgP23H miniswine progeny were created by crossing TgP23H founder miniswine 53-1 with wild type (WT) inbred miniature swine. Scotopic (rod-driven) and photopic (cone-driven) retinal functions were evaluated in F1 TgP23H and WT littermates using full field electroretinograms (ffERGs) at 1, 2, 3, 6, 9, 12, and 18 months of age, as well as the Tg founder miniswine at 6 years of age. Miniswine were euthanized and their retinas processed for morphologic evaluation at the light and electron microscopic level. Retinal morphology of a 36-month-old Tg miniswine also was examined. Results Wild type littermates reached mature scotopic and photopic retinal function by 3 months, while TgP23H miniswine showed abnormal scotopic ffERGs at the earliest time point, 1 month, and depressed photopic ffERGs after 2 months. Rod and cone photoreceptors (PR) exhibited morphologic abnormalities and dropout from the outer nuclear layer at 1 month, with only a monolayer of cone PR somata remaining after 2 months. The retinas showed progressive neural remodeling of the outer retina that included dendritic retraction of rod bipolar cells and glial seal formation by Müller cells. The TgP23H founder miniswine showed cone PR with relatively intact morphology exclusive to the area centralis. Conclusions The F1 Tg miniswine and the TgP23H founder miniswine exhibit similar retinopathy. Translational Relevance TgP23H miniswine are a useful large-eye model to study pathogenesis and preservation cone PRs in humans with retinitis pigmentosa. PMID:28316877

Exosomes-mediated transfer of long noncoding RNA ZFAS1 promotes gastric cancer progression.

PubMed

Pan, Lei; Liang, Wei; Fu, Min; Huang, Zhen-Hua; Li, Xia; Zhang, Wen; Zhang, Peng; Qian, Hui; Jiang, Peng-Cheng; Xu, Wen-Rong; Zhang, Xu

2017-06-01

ZFAS1 is a newly identified long noncoding RNA (lncRNA) that promotes tumor growth and metastasis. Exosomes mediate cellular communications in cancer by transmitting active molecules. The presence of ZFAS1 in the circulating exosomes and the roles of exosomal ZFAS1 in gastric cancer (GC) remains unknown. The aim of this study was to investigate the potential roles of exosomal ZFAS1 in GC. The expression of ZFAS1 was examined in the tumor tissues, serum samples, serum exosomes of GC patients and cell lines using qRT-PCR. The correlation between ZFAS1 expression and the clinicopathological characteristics was analyzed. The characteristics of exosomes were identified using transmission electron microscope (TEM), Nanoparticle Tracking Analysis (NTA), and western blot. The biological roles of ZFAS1 in GC cell growth and mobility were investigated using cell counting, cell colony formation, and transwell migration assay. The potential mechanism of ZFAS1 was demonstrated using flow cytometry, western blot, and qRT-PCR. ZFAS1 expression was elevated in GC cells, tumor tissues, serum and serum exosomes of GC patients. The increased ZFAS1 expression was significantly correlated with lymphatic metastasis and TNM stage. ZFAS1 knockdown inhibited the proliferation and migration of GC cells by suppressing cell cycle progression, inducing apoptosis, and inhibiting epithelial-mesenchymal transition (EMT). On the contrary, ZFAS1 overexpression promoted the proliferation and migration of GC cells. Moreover, ZFAS1 was present in exosomes and could be transmitted by exosomes to enhance GC cell proliferation and migration. ZFAS1 could be delivered by exosomes to promote GC progression, which suggests that ZFAS1 may serve as a potential diagnostic and prognostic biomarker for GC.

Flame Stabilization on Microscopic Scale of Wet Biogas with Microflame

NASA Astrophysics Data System (ADS)

Ida, Tamio; Fuchihata, Manabu; Mizuno, Satoru

Harvesting, transportation, energy conversion and the high-efficient utilization, cascade method and market formation besides become with the indispensable element in order to utilize the biomass resource. There are two type biogases; it is gasified gas from dried biomass by partially combustion and wet biogas from wet biomass by methane fermentation, especially from the livestock excrement resources. This paper discusses an experimental study for flame stabilization on microscopic scale with wet biogas (mainly 0.6CH4+0.4CO2). In this study, the microflame with the wet biogas fuels are formed by the diffusion flame on the coppered straight pipes of inner diameter 0.02mm ˜ 1.5mm. This study is obtained stability mapping on microscopic scale of formed microflame by wet biogas fuels. The flame stability limit conditions on microscopic scale of wet biogas is drawn with blow off and extinction flame double limit lines. It is suggested that minimum mixing spatial scale change by the each mixing ratio of the wet biogas.

Training Medical Novices in Spinal Microsurgery: Does the Modality Matter? A Pilot Study Comparing Traditional Microscopic Surgery and a Novel Robotic Optoelectronic Visualization Tool

PubMed Central

Tubbs, R. Shane; Page, Jeni; Chapman, Alexandra; Burgess, Brittni; Laws, Tyler; Warren, Haylie; Oskouian, Rod J

2016-01-01

The operative microscope has been a staple instrument in the neurosurgical operating room over the last 50 years. With advances in optoelectronics, options such as robotically controlled high magnification have become available. Such robotically controlled optoelectronic systems may offer new opportunities in surgical technique and teaching. However, traditionally trained surgeons may find it hard to accept newer technologies due to an inherent bias emerging from their previous background. We, therefore, studied how a medically naïve population in a pilot study would meet set microsurgical goals in a cadaver experiment using either a conventional operative microscope or BrightMatter™ Servo system, ​a robotically controlled optoelectronic system (Synaptive Medical, Toronto, Ontario, Canada). We found that the relative ease in teaching medical novices with a robotically controlled optoelectronic system was more valuable when compared to using a modern-day surgical microscope. PMID:26973804

Endoscopic vs. microscopic transsphenoidal surgery for Cushing's disease: a systematic review and meta-analysis.

PubMed

Broersen, Leonie H A; Biermasz, Nienke R; van Furth, Wouter R; de Vries, Friso; Verstegen, Marco J T; Dekkers, Olaf M; Pereira, Alberto M

2018-05-16

Systematic review and meta-analysis comparing endoscopic and microscopic transsphenoidal surgery for Cushing's disease regarding surgical outcomes (remission, recurrence, and mortality) and complication rates. To stratify the results by tumor size. Nine electronic databases were searched in February 2017 to identify potentially relevant articles. Cohort studies assessing surgical outcomes or complication rates after endoscopic or microscopic transsphenoidal surgery for Cushing's disease were eligible. Pooled proportions were reported including 95% confidence intervals. We included 97 articles with 6695 patients in total (5711 microscopically and 984 endoscopically operated). Overall, remission was achieved in 5177 patients (80%), with no clear difference between both techniques. Recurrence was around 10% and short term mortality < 0.5% for both techniques. Cerebrospinal fluid leak occurred more often in endoscopic surgery (12.9 vs. 4.0%), whereas transient diabetes insipidus occurred less often (11.3 vs. 21.7%). For microadenomas, results were comparable between both techniques. For macroadenomas, the percentage of patients in remission was higher after endoscopic surgery (76.3 vs. 59.9%), and the percentage recurrence lower after endoscopic surgery (1.5 vs. 17.0%). Endoscopic surgery for patients with Cushing's disease reaches comparable results for microadenomas, and probably better results for macroadenomas than microscopic surgery. This is present despite the presumed learning curve of the newer endoscopic technique, although confounding cannot be excluded. Based on this study, endoscopic surgery may thus be considered the current standard of care. Microscopic surgery can be used based on neurosurgeon's preference. Endocrinologists and neurosurgeons in pituitary centers performing the microscopic technique should at least consider referring Cushing's disease patients with a macroadenoma.

Smartphone adapters for digital photomicrography

PubMed Central

Roy, Somak; Pantanowitz, Liron; Amin, Milon; Seethala, Raja R.; Ishtiaque, Ahmed; Yousem, Samuel A.; Parwani, Anil V.; Cucoranu, Ioan; Hartman, Douglas J.

2014-01-01

Background: Photomicrographs in Anatomic Pathology provide a means of quickly sharing information from a glass slide for consultation, education, documentation and publication. While static image acquisition historically involved the use of a permanently mounted camera unit on a microscope, such cameras may be expensive, need to be connected to a computer, and often require proprietary software to acquire and process images. Another novel approach for capturing digital microscopic images is to use smartphones coupled with the eyepiece of a microscope. Recently, several smartphone adapters have emerged that allow users to attach mobile phones to the microscope. The aim of this study was to test the utility of these various smartphone adapters. Materials and Methods: We surveyed the market for adapters to attach smartphones to the ocular lens of a conventional light microscope. Three adapters (Magnifi, Skylight and Snapzoom) were tested. We assessed the designs of these adapters and their effectiveness at acquiring static microscopic digital images. Results: All adapters facilitated the acquisition of digital microscopic images with a smartphone. The optimal adapter was dependent on the type of phone used. The Magnifi adapters for iPhone were incompatible when using a protective case. The Snapzoom adapter was easiest to use with iPhones and other smartphones even with protective cases. Conclusions: Smartphone adapters are inexpensive and easy to use for acquiring digital microscopic images. However, they require some adjustment by the user in order to optimize focus and obtain good quality images. Smartphone microscope adapters provide an economically feasible method of acquiring and sharing digital pathology photomicrographs. PMID:25191623

Smart align -- A new tool for robust non-rigid registration of scanning microscope data

DOE PAGES

Jones, Lewys; Yang, Hao; Pennycook, Timothy J.; ...

2015-07-10

Many microscopic investigations of materials may benefit from the recording of multiple successive images. This can include techniques common to several types of microscopy such as frame averaging to improve signal-to-noise ratios (SNR) or time series to study dynamic processes or more specific applications. In the scanning transmission electron microscope, this might include focal series for optical sectioning or aberration measurement, beam damage studies or camera-length series to study the effects of strain; whilst in the scanning tunnelling microscope, this might include bias voltage series to probe local electronic structure. Whatever the application, such investigations must begin with the carefulmore » alignment of these data stacks, an operation that is not always trivial. In addition, the presence of low-frequency scanning distortions can introduce intra-image shifts to the data. Here, we describe an improved automated method of performing non-rigid registration customised for the challenges unique to scanned microscope data specifically addressing the issues of low-SNR data, images containing a large proportion of crystalline material and/or local features of interest such as dislocations or edges. Careful attention has been paid to artefact testing of the non-rigid registration method used, and the importance of this registration for the quantitative interpretation of feature intensities and positions is evaluated.« less

Smart align -- A new tool for robust non-rigid registration of scanning microscope data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Lewys; Yang, Hao; Pennycook, Timothy J.

Many microscopic investigations of materials may benefit from the recording of multiple successive images. This can include techniques common to several types of microscopy such as frame averaging to improve signal-to-noise ratios (SNR) or time series to study dynamic processes or more specific applications. In the scanning transmission electron microscope, this might include focal series for optical sectioning or aberration measurement, beam damage studies or camera-length series to study the effects of strain; whilst in the scanning tunnelling microscope, this might include bias voltage series to probe local electronic structure. Whatever the application, such investigations must begin with the carefulmore » alignment of these data stacks, an operation that is not always trivial. In addition, the presence of low-frequency scanning distortions can introduce intra-image shifts to the data. Here, we describe an improved automated method of performing non-rigid registration customised for the challenges unique to scanned microscope data specifically addressing the issues of low-SNR data, images containing a large proportion of crystalline material and/or local features of interest such as dislocations or edges. Careful attention has been paid to artefact testing of the non-rigid registration method used, and the importance of this registration for the quantitative interpretation of feature intensities and positions is evaluated.« less

Dielectric elastomer actuator for the measurement of cell traction forces with sub-cellular resolution

NASA Astrophysics Data System (ADS)

Rosset, Samuel; Poulin, Alexandre; Zollinger, Alicia; Smith, Michael; Shea, Herbert

2017-04-01

We report on the use of dielectric elastomer actuators (DEAs) to measure the traction force field of cells with subcellular resolution. The study of cellular electrochemical and mechanical response to deformation is an important area of research, as mechanotransduction has been shown to be linked with fundamental cell functions, or the progression of diseases such as cancer or atherosclerosis. Experimental cell mechanics is based on two fundamental concepts: the ability to measure cell stiffness, and to apply controlled strains to small clusters of cells. However, there is a lack of tools capable of applying precise deformation to a small cell population while being compatible with an inverted microscope (stable focal plane, transparency, compactness, etc.). Here, we use an anisotropically prestretched silicone-based DEA to deform a soft (7.6kPa) polyacrylamide gel on which the cells are cultured. An array of micro-dots of fluorescent fibronectin is transferred on the gel by micro-contact printing and serves as attachment points for the cells. In addition, the fluorescent dots (which have a diameter of 2 μm with a spacing of 6 μm) are used during the experiment to monitor the traction forces of a single cell (or small cluster of cells). The cell locally exerts traction on the gel, thus deforming the matrix of dots. The position of dots versus time is monitored live when the cells are submitted to a uniaxial strain step. Our deformable bioreactor enables the measurement of the local stiffness of cells submitted to mechanical strain, and is fully compatible with an inverted microscope set-up.

8-oxo-7,8-dihydroguanine level - the DNA oxidative stress marker - recognized by fluorescence image analysis in sporadic uterine adenocarcinomas in women.

PubMed

Postawski, Krzysztof; Przadka-Rabaniuk, Dorota; Piersiak, Tomasz

2013-01-01

In the case of carcinogenesis in human endometrium no information exists on tissue concentration of 8-oxo-7,8-dihydroguanine, the DNA oxidative stress marker This was the main reason to undertake the investigation of this DNA modification in human uterine estrogen-dependent tissue cancers. In order to estimate the level of oxidative damage, 8-oxo-7,8-dihydroguanine was determined directly in cells of tissue microscope slides using OxyDNA Assay Kit, Fluorometric. Cells were investigated under confocal microscope. Images of individual cells were captured by computer-interfaced digital photography and analyzed for fluorescence intensities (continuous inverted 8-bit gray-scale = 0 [black]-255 [white]). Fluorescence scores were calculated for each of 13 normal endometrial samples and 31 uterine adenocarcinoma specimens. Finally the level of the oxidative stress marker was also analyzed according to histological and clinical features of the neoplasms. The obtained data revealed that: 8-oxo-7,8-dihydroguanine levels were higher in uterine adenocarcinomas than in normal endometrial samples (48,32 vs. 38,64; p<0,001); in contrast to normal endometrium there was no correlation between age and DNA oxidative modification content in uterine cancer; highest mean fluorescence intensity was recognized in G2 endometrial adenocarcinomas; level of 8-oxo-7,8-dihydroguanine does not depend on Body Mass Index (BMI) and cancer uterine wall infiltration or tumor FIGO stage. Our study indicates that accumulation of the oxidized DNA base may contribute to the development of endometrial neoplasia, however oxidative DNA damage does not seem to increase with tumor progression.

Microstructure and Properties of Ternary Cu-Ti-Sn Alloy

NASA Astrophysics Data System (ADS)

Wang, Xianhui; Chen, Chunyu; Guo, Tingting; Zou, Juntao; Yang, Xiaohong

2015-07-01

The effect of Sn addition and heat treatment on the microstructure and properties of Cu-3Ti and Cu-2Ti alloys was studied. The microstructure and phase constituents were characterized by an optical microscope, x-ray diffractometer, and transmission electron microscope, and the electrical conductivity and hardness were determined as well. The results show that the as-cast microstructure of Cu-Ti-Sn alloys consists of α-Cu(Ti,Sn) and primary CuSn3Ti5 intermetallic compound. CuSn3Ti5 phase has a hexagonal structure with the lattice parameters a = 0.81737 nm, b = 0.81737 nm, and c = 0.55773 nm. With the increase of aging time, the electrical conductivity progressively increases, while the hardness increases and then decreases. After aging at 450 °C for 8 h, Cu-3Ti-2Sn alloy has an electrical conductivity of 23.1 MS/m and a hardness of 134.5 HV, and the electrical conductivity and hardness of Cu-2Ti-2Sn alloy are 21.5 MS/m and 119.3 HV, respectively. An appropriate aging is beneficial for the precipitation of coherent metastable β'-Cu4Ti phase, which can strengthen Cu-3Ti-2Sn and Cu-2Ti-2Sn alloys. However, a prolonged aging time results in the decrease of hardness due to the formation of incoherent equilibrium β-Cu3Ti phase. The presence of CuSn3Ti5 phase reduces the solute Ti content in the copper matrix and, thus, gives rise to the increase of the electrical conductivity of Cu-Ti-Sn alloys.

Adaptive-Grid Methods for Phase Field Models of Microstructure Development

NASA Technical Reports Server (NTRS)

Dantzig, Jonathan A.; Goldenfeld, Nigel

2001-01-01

Modeling solidification microstructures has become an area of intense study in recent years. The properties of large scale cast products, ranging from automobile engine blocks to aircraft components and other industrial applications, are strongly dependent on the physics that occur at the mesoscopic and microscopic length scales during solidification. The predominant morphology found in solidification microstructures is the dendrite, a tree-like pattern of solid around which solidification proceeds. The microscopic properties of cast products are determined by the length scales of these dendrites, and their associated segregation profiles. For this reason understanding the mechanisms for pattern selection in dendritic growth has attracted a great deal of interest from the experimental and theoretical communities. In particular, a great deal of research has been undertaken to understand such issues as dendrite morphology, shape and growth speed. Experiments on dendrite evolution in pure materials by Glicksman and coworkers on succinonitrile (SCN), and more recently pivalic acid (PVA), as well as other transparent analogs of metals, have provided tests of theories for dendritic growth, and have stimulated considerable theoretical progress. These experiments have clearly demonstrated that in certain parameter ranges the physics of the dendrite tip can be characterized by a steady value for the dendrite tip velocity, radius of curvature and shape. Away from the tip, the time-dependent dendrite exhibits a characteristic sidebranching as it propagates, which is not yet well understood. These experiments are performed by observing individual dendrites growing into an undercooled melt. The experiments are characterized by the dimensionless undercooling. Most experiments are performed at low undercooling.

Diagnostic value and cost utility analysis for urine Gram stain and urine microscopic examination as screening tests for urinary tract infection.

PubMed

Wiwanitkit, Viroj; Udomsantisuk, Nibhond; Boonchalermvichian, Chaiyaporn

2005-06-01

The aim of this study was to evaluate the diagnostic properties of urine Gram stain and urine microscopic examination for screening for urinary tract infection (UTI), and to perform an additional cost utility analysis. This descriptive study was performed on 95 urine samples sent for urine culture to the Department of Microbiology, Faculty of Medicine, Chulalongkorn University. The first part of the study was to determine the diagnostic properties of two screening tests (urine Gram stain and urine microscopic examination). Urine culture was set as the gold standard and the results from both methods were compared to this. The second part of this study was to perform a cost utility analysis. The sensitivity of urine Gram stain was 96.2%, the specificity 93.0%, the positive predictive value 94.3% and the negative predictive value 95.2%. False positives occurred with a frequency of 7.0% and false negatives 3.8%. For the microscopic examination, the sensitivity was 65.4%, specificity 74.4%, positive predictive value 75.6% and negative predictive value 64.0%. False positives occurred with a frequency of 25.6% and false negatives 34.6%. Combining urine Gram stain and urine microscopic examination, the sensitivity was 98.1%, specificity 74.4%, positive predictive value 82.3% and negative predictive value 97.0%. False positives occurred with a frequency of 25.6% and false negatives 1.9%. However, the cost per utility of the combined method was higher than either urine microscopic examination or urine Gram stain alone. Urine Gram stain provided the lowest cost per utility. Economically, urine Gram stain is the proper screening tool for presumptive diagnosis of UTI.

Fine needle aspiration (FNA) of synovial sarcoma--a comparative histological-cytological study of 15 cases, including immunohistochemical, electron microscopic and cytogenetic examination and DNA-ploidy analysis.

PubMed

Akerman, M; Willén, H; Carlén, B; Mandahl, N; Mertens, F

1996-06-01

A retrospective study of 25 FNAs (11 aspirates from primary tumours and 14 from recurrencies and metastases) from 15 synovial sarcomas was performed. The cytological findings were correlated with the histopathology and the value of immunohistochemical and electron microscopic examination as well as DNA-ploidy and cytogenetic analysis for diagnosis were assessed. A reproducible cellular pattern with a reliable diagnosis of spindle cell sarcoma was possible provided that the aspirates were cell rich. However, a true biphasic pattern indicative of synovial sarcoma was only seen in one of the 25 specimens. Electron microscopic examination of the aspirates was a valuable adjunctive diagnostic method, whereas immunocytochemistry and DNA-ploidy analysis were not. Immunohistochemical, electron microscopic and cytogenetic analysis were all valuable ancillary methods when performed on surgical specimens. Malignant haemangiopericytoma and fibrosarcoma were the most important differential diagnoses in the FNA specimens.

Microscopic evaluation and physiochemical analysis of Dillenia indica leaf

PubMed Central

Kumar, S; Kumar, V; Prakash, Om

2011-01-01

Objective To study detail microscopic evaluation and physiochemical analysis of Dillenia indica (D. indica) leaf. Methods Fresh leaf sample and dried power of the leaf were studied macroscopically and microscopically. Preliminary phytochemical investigation of plant material was done. Other WHO recommended parameters for standardizations were also performed. Results The detail microscopy revealed the presence of anomocytic stomata, unicellular trichome, xylem fibres, calcium oxalate crystals, vascular bundles, etc. Leaf constants such as stomatal number, stomatal index, vein-islet number and veinlet termination numbers were also measured. Physiochemical parameters such as ash values, loss on drying, extractive values, percentage of foreign matters, swelling index, etc. were also determined. Preliminary phytochemical screening showed the presence of steroids, terpenoids, glycosides, fatty acids, flavonoids, phenolic compounds and carbohydrates. Conclusions The microscopic and physiochemical analysis of the D. indica leaf is useful in standardization for quality, purity and sample identification. PMID:23569789

Note: Tandem Kirkpatrick-Baez microscope with sixteen channels for high-resolution laser-plasma diagnostics

NASA Astrophysics Data System (ADS)

Yi, Shengzhen; Zhang, Zhe; Huang, Qiushi; Zhang, Zhong; Wang, Zhanshan; Wei, Lai; Liu, Dongxiao; Cao, Leifeng; Gu, Yuqiu

2018-03-01

Multi-channel Kirkpatrick-Baez (KB) microscopes, which have better resolution and collection efficiency than pinhole cameras, have been widely used in laser inertial confinement fusion to diagnose time evolution of the target implosion. In this study, a tandem multi-channel KB microscope was developed to have sixteen imaging channels with the precise control of spatial resolution and image intervals. This precise control was created using a coarse assembly of mirror pairs with high-accuracy optical prisms, followed by precise adjustment in real-time x-ray imaging experiments. The multilayers coated on the KB mirrors were designed to have substantially the same reflectivity to obtain a uniform brightness of different images for laser-plasma temperature analysis. The study provides a practicable method to achieve the optimum performance of the microscope for future high-resolution applications in inertial confinement fusion experiments.

Renal Impairment with Sublethal Tubular Cell Injury in a Chronic Liver Disease Mouse Model

PubMed Central

Ishida, Tokiko; Kotani, Hirokazu; Miyao, Masashi; Kawai, Chihiro; Jemail, Leila; Abiru, Hitoshi; Tamaki, Keiji

2016-01-01

The pathogenesis of renal impairment in chronic liver diseases (CLDs) has been primarily studied in the advanced stages of hepatic injury. Meanwhile, the pathology of renal impairment in the early phase of CLDs is poorly understood, and animal models to elucidate its mechanisms are needed. Thus, we investigated whether an existing mouse model of CLD induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) shows renal impairment in the early phase. Renal injury markers, renal histology (including immunohistochemistry for tubular injury markers and transmission electron microscopy), autophagy, and oxidative stress were studied longitudinally in DDC- and standard diet–fed BALB/c mice. Slight but significant renal dysfunction was evident in DDC-fed mice from the early phase. Meanwhile, histological examinations of the kidneys with routine light microscopy did not show definitive morphological findings, and electron microscopic analyses were required to detect limited injuries such as loss of brush border microvilli and mitochondrial deformities. Limited injuries have been recently designated as sublethal tubular cell injury. As humans with renal impairment, either with or without CLD, often show almost normal tubules, sublethal injury has been of particular interest. In this study, the injuries were associated with mitochondrial aberrations and oxidative stress, a possible mechanism for sublethal injury. Intriguingly, two defense mechanisms were associated with this injury that prevent it from progressing to apparent cell death: autophagy and single-cell extrusion with regeneration. Furthermore, the renal impairment of this model progressed to chronic kidney disease with interstitial fibrosis after long-term DDC feeding. These findings indicated that DDC induces renal impairment with sublethal tubular cell injury from the early phase, leading to chronic kidney disease. Importantly, this CLD mouse model could be useful for studying the pathophysiological mechanisms of sublethal tubular cell injury. PMID:26752420

Studies on rock characteristics and timing of creep at selected landslide sites in Taiwan

Treesearch

Cheng-Yi Lee

2000-01-01

A study was conducted to investigate the causes of and rock characteristics at three landslide sites in the Tesngwen Reservoir watershed of southern Taiwan. Research methods used included the petrographic microscope, X-ray diffraction (XRD), scanning electron microscope (SEM), inductively coupled plasma spectroscope (ICP), constant head permeameter in triaxial...

On the Concept "Microscope": Biology Student Teachers' Cognitive Structure

ERIC Educational Resources Information Center

Kurt, Hakan; Ekici, Gulay; Aktas, Murat; Aksu, Ozlem

2013-01-01

The purpose of the current study is to determine biology student teachers' cognitive structures on the concept of microscope. Qualitative research methodology has been applied in the study. The data were collected from biology student teachers. Free word association test and drawing-writing test were used to collect data. The data collected were…

Overview of nanoscale NEXAFS performed with soft X-ray microscopes.

PubMed

Guttmann, Peter; Bittencourt, Carla

2015-01-01

Today, in material science nanoscale structures are becoming more and more important. Not only for the further miniaturization of semiconductor devices like carbon nanotube based transistors, but also for newly developed efficient energy storage devices, gas sensors or catalytic systems nanoscale and functionalized materials have to be analysed. Therefore, analytical tools like near-edge X-ray absorption fine structure (NEXAFS) spectroscopy has to be applied on single nanostructures. Scanning transmission X-ray microscopes (STXM) as well as full-field transmission X-ray microscopes (TXM) allow the required spatial resolution to study individual nanostructures. In the soft X-ray energy range only STXM was used so far for NEXAFS studies. Due to its unique setup, the TXM operated by the Helmholtz-Zentrum Berlin (HZB) at the electron storage ring BESSY II is the first one in the soft X-ray range which can be used for NEXAFS spectroscopy studies which will be shown in this review. Here we will give an overview of the different microscopes used for NEXAFS studies and describe their advantages and disadvantages for different samples.

Microscope-Integrated OCT Feasibility and Utility With the EnFocus System in the DISCOVER Study.

PubMed

Runkle, Anne; Srivastava, Sunil K; Ehlers, Justis P

2017-03-01

To evaluate the feasibility and utility of a novel microscope-integrated intraoperative optical coherence tomography (OCT) system. The DISCOVER study is an investigational device study evaluating microscope-integrated intraoperative OCT systems for ophthalmic surgery. This report focuses on subjects imaged with the EnFocus prototype system (Leica Microsystems/Bioptigen, Morrisville, NC). OCT was performed at surgeon-directed milestones. Surgeons completed a questionnaire after each case to evaluate the impact of OCT on intraoperative management. Fifty eyes underwent imaging with the EnFocus system. Successful imaging was obtained in 46 of 50 eyes (92%). In eight cases (16%), surgical management was changed based on intraoperative OCT findings. In membrane peeling procedures, intraoperative OCT findings were discordant from the surgeon's initial impression in seven of 20 cases (35%). This study demonstrates the feasibility of microscope-integrated intraoperative OCT using the Bioptigen EnFocus system. Intraoperative OCT may provide surgeons with additional information that may influence surgical decision-making. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:216-222.]. Copyright 2017, SLACK Incorporated.

Some Work and Some Play: Microscopic and Macroscopic Approaches to Labor and Leisure

PubMed Central

Niyogi, Ritwik K.; Shizgal, Peter; Dayan, Peter

2014-01-01

Given the option, humans and other animals elect to distribute their time between work and leisure, rather than choosing all of one and none of the other. Traditional accounts of partial allocation have characterised behavior on a macroscopic timescale, reporting and studying the mean times spent in work or leisure. However, averaging over the more microscopic processes that govern choices is known to pose tricky theoretical problems, and also eschews any possibility of direct contact with the neural computations involved. We develop a microscopic framework, formalized as a semi-Markov decision process with possibly stochastic choices, in which subjects approximately maximise their expected returns by making momentary commitments to one or other activity. We show macroscopic utilities that arise from microscopic ones, and demonstrate how facets such as imperfect substitutability can arise in a more straightforward microscopic manner. PMID:25474151

Particle nonuniformity effects on particle cloud flames in low gravity

NASA Technical Reports Server (NTRS)

Berlad, A. L.; Tangirala, V.; Seshadri, K.; Facca, L. T.; Ogrin, J.; Ross, H.

1991-01-01

Experimental and analytical studies of particle cloud combustion at reduced gravity reveal the substantial roles that particle cloud nonuniformities may play in particle cloud combustion. Macroscopically uniform, quiescent particle cloud systems (at very low gravitational levels and above) sustain processes which can render them nonuniform on both macroscopic and microscopic scales. It is found that a given macroscopically uniform, quiescent particle cloud flame system can display a range of microscopically nonuniform features which lead to a range of combustion features. Microscopically nonuniform particle cloud distributions are difficult experimentally to detect and characterize. A uniformly distributed lycopodium cloud of particle-enriched microscopic nonuniformities in reduced gravity displays a range of burning velocities for any given overall stoichiometry. The range of observed and calculated burning velocities corresponds to the range of particle enriched concentrations within a characteristic microscopic nonuniformity. Sedimentation effects (even in reduced gravity) are also examined.

Sedimentological Investigations of the Martian Surface using the Mars 2001 Robotic Arm Camera and MECA Optical Microscope

NASA Technical Reports Server (NTRS)

Rice, J. W., Jr.; Smith, P. H.; Marshall, J. R.

1999-01-01

The first microscopic sedimentological studies of the Martian surface will commence with the landing of the Mars Polar Lander (MPL) December 3, 1999. The Robotic Arm Camera (RAC) has a resolution of 25 um/p which will permit detailed micromorphological analysis of surface and subsurface materials. The Robotic Ann will be able to dig up to 50 cm below the surface. The walls of the trench will also be inspected by RAC to look for evidence of stratigraphic and / or sedimentological relationships. The 2001 Mars Lander will build upon and expand the sedimentological research begun by the RAC on MPL. This will be accomplished by: (1) Macroscopic (dm to cm): Descent Imager, Pancam, RAC; (2) Microscopic (mm to um RAC, MECA Optical Microscope (Figure 2), AFM This paper will focus on investigations that can be conducted by the RAC and MECA Optical Microscope.

Pathologists dislike sound? Evaluation of a computerised training microscope.

PubMed Central

Gray, E; Duvall, E; Sprey, J; Bird, C C

1998-01-01

AIM: To evaluate the use of multimedia enhancements, using a computerised microscope, in the training of microscope skills. METHODS: The HOME microscope provides facilities to highlight features of interest in conjunction with either text display or aural presentation. A pilot study was carried out with 10 individuals, eight of whom were at different stages of pathology training. A tutorial was implemented employing sound or text, and each individual tested each version. Both the subjective impressions of users and objective measurement of their patterns of use were recorded. RESULTS: Although both versions improved learning, users took longer to work through the aural than the text version; 90% of users preferred the text only version, including all eight individuals involved in pathology training. CONCLUSIONS: Pathologists appear to prefer visual rather than aural input when using teaching systems such as the HOME microscope and sound does not give added value to the training experience. Images PMID:9659250

Influence of mechanical noise inside a scanning electron microscope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaudenzi de Faria, Marcelo; Haddab, Yassine, E-mail: yassine.haddab@femto-st.fr; Le Gorrec, Yann

The scanning electron microscope is becoming a popular tool to perform tasks that require positioning, manipulation, characterization, and assembly of micro-components. However, some of these applications require a higher level of performance with respect to dynamics and precision of positioning. One limiting factor is the presence of unidentified noises and disturbances. This work aims to study the influence of mechanical disturbances generated by the environment and by the microscope, identifying how these can affect elements in the vacuum chamber. To achieve this objective, a dedicated setup, including a high-resolution vibrometer, was built inside the microscope. This work led to themore » identification and quantification of main disturbances and noise sources acting on a scanning electron microscope. Furthermore, the effects of external acoustic excitations were analysed. Potential applications of these results include noise compensation and real-time control for high accuracy tasks.« less

Compact Video Microscope Imaging System Implemented in Colloid Studies

NASA Technical Reports Server (NTRS)

McDowell, Mark

2002-01-01

Long description Photographs showing fiber-optic light source, microscope and charge-coupled discharge (CCD) camera head connected to camera body, CCD camera body feeding data to image acquisition board in PC, and Cartesian robot controlled via PC board. The Compact Microscope Imaging System (CMIS) is a diagnostic tool with intelligent controls for use in space, industrial, medical, and security applications. CMIS can be used in situ with a minimum amount of user intervention. This system can scan, find areas of interest in, focus on, and acquire images automatically. Many multiple-cell experiments require microscopy for in situ observations; this is feasible only with compact microscope systems. CMIS is a miniature machine vision system that combines intelligent image processing with remote control. The software also has a user-friendly interface, which can be used independently of the hardware for further post-experiment analysis. CMIS has been successfully developed in the SML Laboratory at the NASA Glenn Research Center and adapted for use for colloid studies and is available for telescience experiments. The main innovations this year are an improved interface, optimized algorithms, and the ability to control conventional full-sized microscopes in addition to compact microscopes. The CMIS software-hardware interface is being integrated into our SML Analysis package, which will be a robust general-purpose image-processing package that can handle over 100 space and industrial applications.

[Physiological mechanisms of the etiology of visual fatigue during work involving visual stress].

PubMed

Korniushina, T A

2000-01-01

Physiological parameters of vision were studied in three professional groups (a total of 1204 subjects): microscope operators, subjects working with magnifying glasses, and computer users. General and specific features of visual system fatigue formation were identified. Because of complete (in microscope operators) or partial (in subjects working with magnifying glasses and display users) "deprivation" of accommodation, these subjects develop early presbyopia (at the age of 30-35 years). In microscope operators long strain of accommodation system leads to professional myopia, while display users develop pseudomyopia. The highest overstrain is observed after 4 years of work in microscope operators, after 5 years in magnifying glass users, and after 6 years in computer users.

Optimizing the performance of dual-axis confocal microscopes via Monte-Carlo scattering simulations and diffraction theory.

PubMed

Chen, Ye; Liu, Jonathan T C

2013-06-01

Dual-axis confocal (DAC) microscopy has been found to exhibit superior rejection of out-of-focus and multiply scattered background light compared to conventional single-axis confocal microscopy. DAC microscopes rely on the use of separated illumination and collection beam paths that focus and intersect at a single focal volume (voxel) within tissue. While it is generally recognized that the resolution and contrast of a DAC microscope depends on both the crossing angle of the DAC beams, 2θ, and the focusing numerical aperture of the individual beams, α, a detailed study to investigate these dependencies has not been performed. Contrast and resolution are considered as two main criteria to assess the performance of a point-scanned DAC microscope (DAC-PS) and a line-scanned DAC microscope (DAC-LS) as a function of θ and α. The contrast and resolution of these designs are evaluated by Monte-Carlo scattering simulations and diffraction theory calculations, respectively. These results can be used for guiding the optimal designs of DAC-PS and DAC-LS microscopes.

Eight-channel Kirkpatrick-Baez microscope for multiframe x-ray imaging diagnostics in laser plasma experiments.

PubMed

Yi, Shengzhen; Zhang, Zhe; Huang, Qiushi; Zhang, Zhong; Mu, Baozhong; Wang, Zhanshan; Fang, Zhiheng; Wang, Wei; Fu, Sizu

2016-10-01

Because grazing-incidence Kirkpatrick-Baez (KB) microscopes have better resolution and collection efficiency than pinhole cameras, they have been widely used for x-ray imaging diagnostics of laser inertial confinement fusion. The assembly and adjustment of a multichannel KB microscope must meet stringent requirements for image resolution and reproducible alignment. In the present study, an eight-channel KB microscope was developed for diagnostics by imaging self-emission x-rays with a framing camera at the Shenguang-II Update (SGII-Update) laser facility. A consistent object field of view is ensured in the eight channels using an assembly method based on conical reference cones, which also allow the intervals between the eight images to be tuned to couple with the microstrips of the x-ray framing camera. The eight-channel KB microscope was adjusted via real-time x-ray imaging experiments in the laboratory. This paper describes the details of the eight-channel KB microscope, its optical and multilayer design, the assembly and alignment methods, and results of imaging in the laboratory and at the SGII-Update.

Performance evaluation of image segmentation algorithms on microscopic image data.

PubMed

Beneš, Miroslav; Zitová, Barbara

2015-01-01

In our paper, we present a performance evaluation of image segmentation algorithms on microscopic image data. In spite of the existence of many algorithms for image data partitioning, there is no universal and 'the best' method yet. Moreover, images of microscopic samples can be of various character and quality which can negatively influence the performance of image segmentation algorithms. Thus, the issue of selecting suitable method for a given set of image data is of big interest. We carried out a large number of experiments with a variety of segmentation methods to evaluate the behaviour of individual approaches on the testing set of microscopic images (cross-section images taken in three different modalities from the field of art restoration). The segmentation results were assessed by several indices used for measuring the output quality of image segmentation algorithms. In the end, the benefit of segmentation combination approach is studied and applicability of achieved results on another representatives of microscopic data category - biological samples - is shown. © 2014 The Authors Journal of Microscopy © 2014 Royal Microscopical Society.

Assessing delivery and quantifying efficacy of small interfering ribonucleic acid therapeutics in the skin using a dual-axis confocal microscope

NASA Astrophysics Data System (ADS)

Ra, Hyejun; Gonzalez-Gonzalez, Emilio; Smith, Bryan R.; Gambhir, Sanjiv S.; Kino, Gordon S.; Solgaard, Olav; Kaspar, Roger L.; Contag, Christopher H.

2010-05-01

Transgenic reporter mice and advances in imaging instrumentation are enabling real-time visualization of cellular mechanisms in living subjects and accelerating the development of novel therapies. Innovative confocal microscope designs are improving their utility for microscopic imaging of fluorescent reporters in living animals. We develop dual-axis confocal (DAC) microscopes for such in vivo studies and create mouse models where fluorescent proteins are expressed in the skin for the purpose of advancing skin therapeutics and transdermal delivery tools. Three-dimensional image volumes, through the different skin compartments of the epidermis and dermis, can be acquired in several seconds with the DAC microscope in living mice, and are comparable to histologic analyses of reporter protein expression patterns in skin sections. Intravital imaging with the DAC microscope further enables visualization of green fluorescent protein (GFP) reporter gene expression in the skin over time, and quantification of transdermal delivery of small interfering RNA (siRNA) and therapeutic efficacy. Visualization of transdermal delivery of nucleic acids will play an important role in the development of innovative strategies for treating skin pathologies.

Application of microscopy in authentication of traditional Tibetan medicinal plants of five Rhodiola (Crassulaceae) alpine species by comparative anatomy and micromorphology.

PubMed

Li, Tao; Zhang, Hao

2008-06-01

A comparative analysis was undertaken to conduct an anatomical and micromorphological study of five species of Rhodiola-R. kirilowii, R. yunnanensis, R. crenulata, R. fastigata, and R. quadrifida-collected from the western Sichuan province plateau of China. Rhodiola plants are a popularly used ethnodrug from the Qinghai-Tibetan plateau of China. Modern studies have shown that the plants of Rhodiola possess different pharmacological activities, chemical constituents, and efficiencies in clinical application. To distinguish five main species of Rhodiola and ensure their safety and efficacy, microscopic characteristics of roots, rhizomes, and stems, including transverse sections, stem and foliar epidermis, as well as the crude drug powder, were observed. The fixed, sectioned, and stained plant materials, as well as the crude powder, were studied using a light microscope according to the usual microscopic techniques. The results of the microscopic features were systematically and comparatively described and illustrated. The five species have distinct microscopic characteristic differences, thus allowing us to distinguish between the species. Also, semi-quantitative and quantitative micrographic parameter tables were simultaneously presented. Further, a key to the five species and a comparative chart of the key authentication parameters based on these anatomic characteristics analyzed was drawn up and is presented for the Rhodiola species studied. The study indicated that light microscopy and related techniques provide a method that is convenient, feasible, and can be unambiguously applied to the authentication of species of Rhodiola. (c) 2008 Wiley-Liss, Inc.

Heterotypic mouse models of canine osteosarcoma recapitulate tumor heterogeneity and biological behavior

PubMed Central

Tomiyasu, Hirotaka; Garbe, John R.; Cornax, Ingrid; Amaya, Clarissa; O'Sullivan, M. Gerard; Subramanian, Subbaya

2016-01-01

ABSTRACT Osteosarcoma (OS) is a heterogeneous and rare disease with a disproportionate impact because it mainly affects children and adolescents. Lamentably, more than half of patients with OS succumb to metastatic disease. Clarification of the etiology of the disease, development of better strategies to manage progression, and methods to guide personalized treatments are among the unmet health needs for OS patients. Progress in managing the disease has been hindered by the extreme heterogeneity of OS; thus, better models that accurately recapitulate the natural heterogeneity of the disease are needed. For this study, we used cell lines derived from two spontaneous canine OS tumors with distinctly different biological behavior (OS-1 and OS-2) for heterotypic in vivo modeling that recapitulates the heterogeneous biology and behavior of this disease. Both cell lines demonstrated stability of the transcriptome when grown as orthotopic xenografts in athymic nude mice. Consistent with the behavior of the original tumors, OS-2 xenografts grew more rapidly at the primary site and had greater propensity to disseminate to lung and establish microscopic metastasis. Moreover, OS-2 promoted formation of a different tumor-associated stromal environment than OS-1 xenografts. OS-2-derived tumors comprised a larger percentage of the xenograft tumors than OS-1-derived tumors. In addition, a robust pro-inflammatory population dominated the stromal cell infiltrates in OS-2 xenografts, whereas a mesenchymal population with a gene signature reflecting myogenic signaling dominated those in the OS-1 xenografts. Our studies show that canine OS cell lines maintain intrinsic features of the tumors from which they were derived and recapitulate the heterogeneous biology and behavior of bone cancer in mouse models. This system provides a resource to understand essential interactions between tumor cells and the stromal environment that drive the progression and metastatic propensity of OS. PMID:27874835

Heterotypic mouse models of canine osteosarcoma recapitulate tumor heterogeneity and biological behavior.

PubMed

Scott, Milcah C; Tomiyasu, Hirotaka; Garbe, John R; Cornax, Ingrid; Amaya, Clarissa; O'Sullivan, M Gerard; Subramanian, Subbaya; Bryan, Brad A; Modiano, Jaime F

2016-12-01

Osteosarcoma (OS) is a heterogeneous and rare disease with a disproportionate impact because it mainly affects children and adolescents. Lamentably, more than half of patients with OS succumb to metastatic disease. Clarification of the etiology of the disease, development of better strategies to manage progression, and methods to guide personalized treatments are among the unmet health needs for OS patients. Progress in managing the disease has been hindered by the extreme heterogeneity of OS; thus, better models that accurately recapitulate the natural heterogeneity of the disease are needed. For this study, we used cell lines derived from two spontaneous canine OS tumors with distinctly different biological behavior (OS-1 and OS-2) for heterotypic in vivo modeling that recapitulates the heterogeneous biology and behavior of this disease. Both cell lines demonstrated stability of the transcriptome when grown as orthotopic xenografts in athymic nude mice. Consistent with the behavior of the original tumors, OS-2 xenografts grew more rapidly at the primary site and had greater propensity to disseminate to lung and establish microscopic metastasis. Moreover, OS-2 promoted formation of a different tumor-associated stromal environment than OS-1 xenografts. OS-2-derived tumors comprised a larger percentage of the xenograft tumors than OS-1-derived tumors. In addition, a robust pro-inflammatory population dominated the stromal cell infiltrates in OS-2 xenografts, whereas a mesenchymal population with a gene signature reflecting myogenic signaling dominated those in the OS-1 xenografts. Our studies show that canine OS cell lines maintain intrinsic features of the tumors from which they were derived and recapitulate the heterogeneous biology and behavior of bone cancer in mouse models. This system provides a resource to understand essential interactions between tumor cells and the stromal environment that drive the progression and metastatic propensity of OS. © 2016. Published by The Company of Biologists Ltd.

Impact of Microscope-Integrated OCT on Ophthalmology Resident Performance of Anterior Segment Surgical Maneuvers in Model Eyes.

PubMed

Todorich, Bozho; Shieh, Christine; DeSouza, Philip J; Carrasco-Zevallos, Oscar M; Cunefare, David L; Stinnett, Sandra S; Izatt, Joseph A; Farsiu, Sina; Mruthyunjaya, Privthi; Kuo, Anthony N; Toth, Cynthia A

2016-07-01

The integration of swept-source optical coherence tomography (SS-OCT) into the operating microscope enables real-time, tissue-level three-dimensional (3D) imaging to aid in ophthalmic microsurgery. In this prospective randomized controlled study, we evaluated the impact of SS microscope-integrated OCT (MI-OCT) on ophthalmology residents' performance of ophthalmic microsurgical maneuvers. Fourteen ophthalmology residents from a single institution were stratified by year of training and randomized to perform four anterior segment surgical maneuvers on porcine eyes with (MI-OCT+) or without (MI-OCT-) direct intraoperative OCT guidance. Subsequently, both groups repeated the same maneuvers without MI-OCT feedback to test whether initial MI-OCT experience affected subsequent surgical performance. Finally, the MI-OCT- group was crossed over and allowed to repeat the same maneuvers with direct MI-OCT guidance. Each resident completed a survey at the completion of the study. With direct MI-OCT feedback, residents demonstrated enhanced performance in depth-based anterior segment maneuvers (corneal suture passes at 50% and 90% depth and corneal laceration repair) compared with the residents operating without MI-OCT. Microscope-integrated OCT+ residents continued to outperform the controls when both groups subsequently operated without MI-OCT. For clear corneal wound geometry, there was no statistically significant effect of MI-OCT as applied in this study. Overall, the resident surgeons rated their subjective experience of using MI-OCT very favorably. Microscope-integrated OCT feedback enhances performance of ophthalmology residents in select anterior segment surgical maneuvers. Microscope-integrated OCT represents a valuable tool in the surgical education of ophthalmology residents.

Iatrogenic surgical microscope skin burns: A systematic review of the literature and case report.

PubMed

Lopez, Joseph; Soni, Ashwin; Calva, Daniel; Susarla, Srinivas M; Jallo, George I; Redett, Richard

2016-06-01

Cutaneous burns associated with microscope-use are perceived to be uncommon adverse events in microsurgery. Currently, it is unknown what factors are associated with these iatrogenic events. In this report, we describe the case of a 1-year-old patient who suffered a full thickness skin burn from a surgical microscope after a L4-S1 laminectomy. Additionally, we present a systematic review of the literature that assessed the preoperative risk, outcome, and management of iatrogenic microscope skin burns. Lastly, a summary of the Food and Drug Administration's (FDA) Manufacturer and User Facility Device Experience (MAUDE) database of voluntary adverse events was reviewed and analyzed for clinical cases of microscope thermal injuries. The systematic literature review identified only seven articles related to microsurgery-related cutaneous burns. From these seven studies, 15 clinical cases of iatrogenic skin burns were extracted for analysis. The systematic review of the FDA MAUDE database revealed only 60 cases of cutaneous burns associated with surgical microscopes since 2004. Few cases of microscope burns have been described in the literature; this report is, to our knowledge, one of the first comprehensive reports of this iatrogenic event in the literature. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Microscopic colitis: the tip of the iceberg?

PubMed

Kitchen, Paul A; Levi, A Jonathen; Domizio, Paula; Talbot, Ian C; Forbes, Alastair; Price, Ashley B

2002-11-01

The aims were to determine whether a wide variation exists between hospitals in the diagnosis of microscopic colitis and to assimilate clinical data. Retrospective study of 90 patients with microscopic colitis aged between 16 and 92 years from 11 hospitals in south-east England. A questionnaire was designed to collect relevant data from all patients in whom a new diagnosis of microscopic colitis had been made at the source hospital between January 1990 and December 1996. The inclusion criteria were presentation with watery diarrhoea, a normal endoscopy and a histological report of microscopic colitis. Histology slides were then requested and reviewed. Clinical data were analysed with reference to the confirmed diagnosis. The number of patients diagnosed at each hospital ranged between zero and 30, with a median of six. Sixty-eight patients had histological slides reviewed. The numbers of patients with a final reviewed diagnosis of collagenous colitis, lymphocytic colitis and microscopic colitis, type undesignated, were 37, 18 and seven respectively. In thirty-one patients (34%) there was a recent history of the use of non-steroidal anti-inflammatory drugs. These data confirm that there is wide hospital variation in the diagnosis of microscopic colitis. Furthermore, the small group with the undesignated type may be associated with the use of non-steroidal anti-inflammatory drugs.

Nature Study with the Microscope.

ERIC Educational Resources Information Center

Sollberger, Dwight E.

1991-01-01

Identifies specific instruction difficulties, potential problems, solutions, and activities for successful use of microscopes in the classroom. Procedures are outlined for guiding students in creating their own slides with monocotyledon and dicotyledon stems, fern spores, stomata, lichens, and red onions. (MCO)

Persistent extraradicular infection in root-filled asymptomatic human tooth: scanning electron microscopic analysis and microbial investigation after apical microsurgery.

PubMed

Signoretti, Fernanda G C; Endo, Marcos S; Gomes, Brenda P F A; Montagner, Francisco; Tosello, Fernanda B; Jacinto, Rogério C

2011-12-01

Procedural accidents have a negative effect on healing and might contribute to the persistence of infections in inaccessible apical areas, requiring surgical intervention. This report describes a case of persistent apical periodontitis of a lower left first molar associated with the sinus tract and a periapical lesion that required nonsurgical endodontic retreatment and apical surgery for resolution. The tooth had received endodontic treatment 3 years ago and had to be retreated using the crown-down technique with chemical auxiliary substance (2% chlorhexidine gel), foramen patency, and enlargement and was filled in a single appointment. The occlusal access cavity was immediately restored with composite resin. After 1 month, it could be observed that the sinus tract persisted and, radiographically, the lesion remained unaltered. Therefore, endodontic microsurgery was indicated. Apical microsurgery was performed under magnification with the use of a dental operating microscope including apicectomy, root end with ultrasound, and sealing with mineral trioxide aggregate. A microbiological sample was collected from the apical lesion. The resected distal root apex was observed by scanning electron microscopy. The following species were detected: Actinomyces naeslundii and Actinomyces meyeri, Propionibacterium propionicum, Clostridium botullinum, Parvimonas micra, and Bacteroides ureolyticus; scanning electron microscopic analysis revealed bacterial biofilm surrounding the apical foramen and external radicular surface. Gutta-percha overfilling at the apex because of a zip caused during initial endodontic treatment could be observed. A 6-month follow-up showed apparent radiographic periapical healing, which progressed after 24 months. Gram-positive anaerobic bacteria and extraradicular biofilm seem to participate in the maintenance of persistent periapical pathology, and endodontic retreatment followed by periapical microsurgery proved to be a successful alternative in the resolution of persistent extraradicular infections. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Comparison of Near-Infrared Imaging Camera Systems for Intracranial Tumor Detection.

PubMed

Cho, Steve S; Zeh, Ryan; Pierce, John T; Salinas, Ryan; Singhal, Sunil; Lee, John Y K

2018-04-01

Distinguishing neoplasm from normal brain parenchyma intraoperatively is critical for the neurosurgeon. 5-Aminolevulinic acid (5-ALA) has been shown to improve gross total resection and progression-free survival but has limited availability in the USA. Near-infrared (NIR) fluorescence has advantages over visible light fluorescence with greater tissue penetration and reduced background fluorescence. In order to prepare for the increasing number of NIR fluorophores that may be used in molecular imaging trials, we chose to compare a state-of-the-art, neurosurgical microscope (System 1) to one of the commercially available NIR visualization platforms (System 2). Serial dilutions of indocyanine green (ICG) were imaged with both systems in the same environment. Each system's sensitivity and dynamic range for NIR fluorescence were documented and analyzed. In addition, brain tumors from six patients were imaged with both systems and analyzed. In vitro, System 2 demonstrated greater ICG sensitivity and detection range (System 1 1.5-251 μg/l versus System 2 0.99-503 μg/l). Similarly, in vivo, System 2 demonstrated signal-to-background ratio (SBR) of 2.6 ± 0.63 before dura opening, 5.0 ± 1.7 after dura opening, and 6.1 ± 1.9 after tumor exposure. In contrast, System 1 could not easily detect ICG fluorescence prior to dura opening with SBR of 1.2 ± 0.15. After the dura was reflected, SBR increased to 1.4 ± 0.19 and upon exposure of the tumor SBR increased to 1.8 ± 0.26. Dedicated NIR imaging platforms can outperform conventional microscopes in intraoperative NIR detection. Future microscopes with improved NIR detection capabilities could enhance the use of NIR fluorescence to detect neoplasm and improve patient outcome.

Advanced Characterization Techniques for Sodium-Ion Battery Studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shadike, Zulipiya; Zhao, Enyue; Zhou, Yong-Ning

Sodium (Na)-ion batteries (NIBs) are considered promising alternative candidates to the well-commercialized lithium-ion batteries, especially for applications in large-scale energy storage systems. The electrochemical performance of NIBs such as the cyclability, rate capability, and voltage profiles are strongly dependent on the structural and morphological evolution, phase transformation, sodium-ion diffusion, and electrode/electrolyte interface reconstruction during charge–discharge cycling. Therefore, in-depth understanding of the structure and kinetics of electrode materials and the electrode/electrolyte interfaces is essential for optimizing current NIB systems and exploring new materials for NIBs. Recently, rapid progress and development in spectroscopic, microscopic, and scattering techniques have provided extensive insight intomore » the nature of structural evolution, morphological changes of electrode materials, and electrode/electrolyte interface in NIBs. Here in this review, a comprehensive overview of both static (ex situ) and real-time (in situ or in operando) techniques for studying the NIBs is provided. Lastly, special focus is placed on how these techniques are applied to the fundamental investigation of NIB systems and what important results are obtained.« less

Numerical approaches to combustion modeling. Progress in Astronautics and Aeronautics. Vol. 135

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oran, E.S.; Boris, J.P.

1991-01-01

Various papers on numerical approaches to combustion modeling are presented. The topics addressed include; ab initio quantum chemistry for combustion; rate coefficient calculations for combustion modeling; numerical modeling of combustion of complex hydrocarbons; combustion kinetics and sensitivity analysis computations; reduction of chemical reaction models; length scales in laminar and turbulent flames; numerical modeling of laminar diffusion flames; laminar flames in premixed gases; spectral simulations of turbulent reacting flows; vortex simulation of reacting shear flow; combustion modeling using PDF methods. Also considered are: supersonic reacting internal flow fields; studies of detonation initiation, propagation, and quenching; numerical modeling of heterogeneous detonations, deflagration-to-detonationmore » transition to reactive granular materials; toward a microscopic theory of detonations in energetic crystals; overview of spray modeling; liquid drop behavior in dense and dilute clusters; spray combustion in idealized configurations: parallel drop streams; comparisons of deterministic and stochastic computations of drop collisions in dense sprays; ignition and flame spread across solid fuels; numerical study of pulse combustor dynamics; mathematical modeling of enclosure fires; nuclear systems.« less

Advanced Characterization Techniques for Sodium-Ion Battery Studies

DOE PAGES

Shadike, Zulipiya; Zhao, Enyue; Zhou, Yong-Ning; ...

2018-02-19

Sodium (Na)-ion batteries (NIBs) are considered promising alternative candidates to the well-commercialized lithium-ion batteries, especially for applications in large-scale energy storage systems. The electrochemical performance of NIBs such as the cyclability, rate capability, and voltage profiles are strongly dependent on the structural and morphological evolution, phase transformation, sodium-ion diffusion, and electrode/electrolyte interface reconstruction during charge–discharge cycling. Therefore, in-depth understanding of the structure and kinetics of electrode materials and the electrode/electrolyte interfaces is essential for optimizing current NIB systems and exploring new materials for NIBs. Recently, rapid progress and development in spectroscopic, microscopic, and scattering techniques have provided extensive insight intomore » the nature of structural evolution, morphological changes of electrode materials, and electrode/electrolyte interface in NIBs. Here in this review, a comprehensive overview of both static (ex situ) and real-time (in situ or in operando) techniques for studying the NIBs is provided. Lastly, special focus is placed on how these techniques are applied to the fundamental investigation of NIB systems and what important results are obtained.« less

A Microstructurally Inspired Damage Model for Early Venous Thrombus

PubMed Central

Rausch, Manuel K.; Humphrey, Jay D.

2015-01-01

Accumulative damage may be an important contributor to many cases of thrombotic disease progression. Thus, a complete understanding of the pathological role of thrombus requires an understanding of its mechanics and in particular mechanical consequences of damage. In the current study, we introduce a novel microstructurally inspired constitutive model for thrombus that considers a non-uniform distribution of microstructural fibers at various crimp levels and employs one of the distribution parameters to incorporate stretch-driven damage on the microscopic level. To demonstrate its ability to represent the mechanical behavior of thrombus, including a recently reported Mullins type damage phenomenon, we fit our model to uniaxial tensile test data of early venous thrombus. Our model shows an agreement with these data comparable to previous models for damage in elastomers with the added advantages of a microstructural basis and fewer model parameters. We submit that our novel approach marks another important step toward modeling the evolving mechanics of intraluminal thrombus, specifically its damage, and hope it will aid in the study of physiological and pathological thrombotic events. PMID:26523784

High-Speed Automatic Microscopy for Real Time Tracks Reconstruction in Nuclear Emulsion

NASA Astrophysics Data System (ADS)

D'Ambrosio, N.

2006-06-01

The Oscillation Project with Emulsion-tRacking Apparatus (OPERA) experiment will use a massive nuclear emulsion detector to search for /spl nu//sub /spl mu///spl rarr//spl nu//sub /spl tau// oscillation by identifying /spl tau/ leptons through the direct detection of their decay topology. The feasibility of experiments using a large mass emulsion detector is linked to the impressive progress under way in the development of automatic emulsion analysis. A new generation of scanning systems requires the development of fast automatic microscopes for emulsion scanning and image analysis to reconstruct tracks of elementary particles. The paper presents the European Scanning System (ESS) developed in the framework of OPERA collaboration.

Focal nodular hyperplasia with major sinusoidal dilatation: a misleading entity

PubMed Central

Laumonier, Hervé; Frulio, Nora; Laurent, Christophe; Balabaud, Charles; Zucman-Rossi, Jessica; Bioulac-Sage, Paulette

2010-01-01

Focal nodular hyperplasia (FNH) is a benign liver lesion thought to be a non-specific response to locally increased blood flow. Although the diagnosis of FNH and hepatocellular adenoma (HCA) has made great progress over the last few years using modern imaging techniques, there are still in daily practice some difficulties concerning some atypical nodules. Here, the authors report the case of a 47-year-old woman with a single liver lesion thought to be, by imaging, an inflammatory HCA with major sinusoidal congestion. This nodule was revealed to be, at the microscopical level and after specific immunostaining and molecular analysis, an FNH with sinusoidal dilatation (so-called telangiectatic focal nodular hyperplasia). PMID:22798311

Stereotactic ablative body radiotherapy combined with immunotherapy: present status and future perspectives.

PubMed

Rekers, N H; Troost, E G C; Zegers, C M L; Germeraad, W T V; Dubois, L J; Lambin, P

2014-10-01

Radiotherapy is along with surgery and chemotherapy one of the prime treatment modalities in cancer. It is applied in the primary, neoadjuvant as well as the adjuvant setting. Radiation techniques have rapidly evolved during the past decade enabling the delivery of high radiation doses, reducing side-effects in tumour-adjacent normal tissues. While increasing local tumour control, current and future efforts ought to deal with microscopic disease at a distance of the primary tumour, ultimately responsible for disease-progression. This review explores the possibility of bimodal treatment combining radiotherapy with immunotherapy. Copyright © 2014 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

Nuclear microscopy in Parkinson's disease

NASA Astrophysics Data System (ADS)

Watt, F.; Lee, T.; Thong, P. S. P.; Tang, S. M.

1995-09-01

Rats have been subjected to unilateral lesioning with the selective neurotoxin 6-OHDA in order to induce Parkinsonism. Analysis using the NUS Nuclear Microscope facility have shown that iron levels are raised by an average of 26% in the lesioned subtantia nigra region of the brain compared with the non-lesioned side. In addition the background tissue level of iron is also elevated by 31% in the lesioned side, indicating that there is a general increase in iron levels as a result of the lesioning. This result is consistent with the other observations that other diseases of the brain are frequently associated with altered iron levels (eg. progressive nuclear palsy, multiple system atrophy, Alzheimers disease, multiple sclerosis).