Image Montaging for Creating a Virtual Pathology Slide: An Innovative and Economical Tool to Obtain a Whole Slide Image.

PubMed

Banavar, Spoorthi Ravi; Chippagiri, Prashanthi; Pandurangappa, Rohit; Annavajjula, Saileela; Rajashekaraiah, Premalatha Bidadi

2016-01-01

Background . Microscopes are omnipresent throughout the field of biological research. With microscopes one can see in detail what is going on at the cellular level in tissues. Though it is a ubiquitous tool, the limitation is that with high magnification there is a small field of view. It is often advantageous to see an entire sample at high magnification. Over the years technological advancements in optics have helped to provide solutions to this limitation of microscopes by creating the so-called dedicated "slide scanners" which can provide a "whole slide digital image." These scanners can provide seamless, large-field-of-view, high resolution image of entire tissue section. The only disadvantage of such complete slide imaging system is its outrageous cost, thereby hindering their practical use by most laboratories, especially in developing and low resource countries. Methods . In a quest for their substitute, we tried commonly used image editing software Adobe Photoshop along with a basic image capturing device attached to a trinocular microscope to create a digital pathology slide. Results . The seamless image created using Adobe Photoshop maintained its diagnostic quality. Conclusion . With time and effort photomicrographs obtained from a basic camera-microscope set up can be combined and merged in Adobe Photoshop to create a whole slide digital image of practically usable quality at a negligible cost.

Preparing soft-bodied arthropods for arthropods for microscope examination: Armored Scales (Insects: Hemiptera: Diaspididae)

USDA-ARS?s Scientific Manuscript database

Proper identification of armored scales (Hemiptera: Diaspididae) requires preparation of the specimen on a microscope slide. This training video provides visual instruction on how to prepare armored scales specimens on microscope slides for examination and identification. Steps ranging from collect...

An Antique Microscope Slide Brings the Thrill of Discovery into a Contemporary Biology Classroom

ERIC Educational Resources Information Center

Reiser, Frank

2012-01-01

The discovery of a Victorian-era microscope slide titled "Grouped Flower Seeds" began an investigation into the scientific and historical background of the antique slide to develop its usefulness as a multidisciplinary tool for PowerPoint presentations usable in contemporary biology classrooms, particularly large-enrollment sections. The resultant…

A densitometric analysis of commercial 35mm films

NASA Technical Reports Server (NTRS)

Hammond, Ernest C., Jr.; Ruffin, Christopher, III

1989-01-01

IIaO films have been subjected to various sensitometric tests. The have included thermal and aging effects and reciprocity failure studies. In order to compare the special IIaO film with popular brands of 35 mm films and their possible use in astrophotography, Agfa, Fuji and Kodak print and slide formats, as well as black and white and color formats, were subjected to sensitometric, as well as densitometric analysis. A scanning electron microscope was used to analyze grain structure size, and shape as a function of both speed and brand. Preliminary analysis of the grain structure using an ISI-SS40 scanning electron microscope indicates that the grain sizes for darker densities are much larger than the grain size for lighter densities. Researchers analyze the scanning electron microscope findings of the various grains versus densities as well as enhancement of the grains, using the IP-8500 Digital Image Processor.

Identification of mycobacterium tuberculosis in sputum smear slide using automatic scanning microscope

NASA Astrophysics Data System (ADS)

Rulaningtyas, Riries; Suksmono, Andriyan B.; Mengko, Tati L. R.; Saptawati, Putri

2015-04-01

Sputum smear observation has an important role in tuberculosis (TB) disease diagnosis, because it needs accurate identification to avoid high errors diagnosis. In development countries, sputum smear slide observation is commonly done with conventional light microscope from Ziehl-Neelsen stained tissue and it doesn't need high cost to maintain the microscope. The clinicians do manual screening process for sputum smear slide which is time consuming and needs highly training to detect the presence of TB bacilli (mycobacterium tuberculosis) accurately, especially for negative slide and slide with less number of TB bacilli. For helping the clinicians, we propose automatic scanning microscope with automatic identification of TB bacilli. The designed system modified the field movement of light microscope with stepper motor which was controlled by microcontroller. Every sputum smear field was captured by camera. After that some image processing techniques were done for the sputum smear images. The color threshold was used for background subtraction with hue canal in HSV color space. Sobel edge detection algorithm was used for TB bacilli image segmentation. We used feature extraction based on shape for bacilli analyzing and then neural network classified TB bacilli or not. The results indicated identification of TB bacilli that we have done worked well and detected TB bacilli accurately in sputum smear slide with normal staining, but not worked well in over staining and less staining tissue slide. However, overall the designed system can help the clinicians in sputum smear observation becomes more easily.

Factors to keep in mind when introducing virtual microscopy.

PubMed

Glatz-Krieger, Katharina; Spornitz, Udo; Spatz, Alain; Mihatsch, Michael J; Glatz, Dieter

2006-03-01

Digitization of glass slides and delivery of so-called virtual slides (VS) emulating a real microscope over the Internet have become reality due to recent improvements in technology. We have implemented a virtual microscope for instruction of medical students and for continuing medical education. Up to 30,000 images per slide are captured using a microscope with an automated stage. The images are post-processed and then served by a plain hypertext transfer protocol (http)-server. A virtual slide client (vMic) based on Macromedia's Flash MX, a highly accepted technology available on every modern Web browser, has been developed. All necessary virtual slide parameters are stored in an XML file together with the image. Evaluation of the courses by questionnaire indicated that most students and many but not all pathologists regard virtual slides as an adequate replacement for traditional slides. All our virtual slides are publicly accessible over the World Wide Web (WWW) at http://vmic.unibas.ch . Recently, several commercially available virtual slide acquisition systems (VSAS) have been developed that use various technologies to acquire and distribute virtual slides. These systems differ in speed, image quality, compatibility, viewer functionalities and price. This paper gives an overview of the factors to keep in mind when introducing virtual microscopy.

Transition of a dental histology course from light to virtual microscopy.

PubMed

Weaker, Frank J; Herbert, Damon C

2009-10-01

The transition of the dental histology course at the University of Texas Health Science Center at San Antonio Dental School was completed gradually over a five-year period. A pilot project was initially conducted to study the feasibility of integrating virtual microscopy into a traditional light microscopic lecture and laboratory course. Because of the difficulty of procuring quality calcified and decalcified sections of teeth, slides from the student loan collection in the oral histology block of the course were outsourced for conversion to digital images and placed on DVDs along with a slide viewer. The slide viewer mimicked the light microscope, allowing horizontal and vertical movement and changing of magnification, and, in addition, a feature to capture static images. In a survey, students rated the ease of use of the software, quality of the images, maneuverability of the images, and questions regarding use of the software, effective use of laboratory, and faculty time. Because of the positive support from the students, our entire student loan collection of 153 glass slides was subsequently converted to virtual images and distributed on an Apricorn pocket external hard drive. Students were asked to assess the virtual microscope over a four-year period. As a result of the surveys, light microscopes have been totally eliminated, and microscope exams have been replaced with project slide examinations. In the future, we plan to expand our virtual slides and incorporate computer testing.

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

Compact, Automated Centrifugal Slide-Staining System

NASA Technical Reports Server (NTRS)

Feeback, Daniel L.; Clarke, Mark S. F.

2004-01-01

The Directional Acceleration Vector-Driven Displacement of Fluids (DAVD-DOF) system, under development at the time of reporting the information for this article, would be a relatively compact, automated, centrifugally actuated system for staining blood smears and other microbiological samples on glass microscope slides in either a microgravitational or a normal Earth gravitational environment. The DAVD-DOF concept is a successor to the centrifuge-operated slide stainer (COSS) concept, which was reported in Slide-Staining System for Microgravity or Gravity (MSC-22949), NASA Tech Briefs, Vol. 25, No. 1 (January, 2001), page 64. The COSS includes reservoirs and a staining chamber that contains a microscope slide to which a biological sample is affixed. The staining chamber is sequentially filled with and drained of staining and related liquids from the reservoirs by use of a weighted plunger to force liquid from one reservoir to another at a constant level of hypergravity maintained in a standard swing-bucket centrifuge. In the DAVD-DOF system, a staining chamber containing a sample would also be sequentially filled and emptied, but with important differences. Instead of a simple microscope slide, one would use a special microscope slide on which would be fabricated a network of very small reservoirs and narrow channels connected to a staining chamber (see figure). Unlike in the COSS, displacement of liquid would be effected by use of the weight of the liquid itself, rather than the weight of a plunger.

"The living picture": on the circulation of microscope-slide knowledge in 1903.

PubMed

Gaycken, Oliver

2013-01-01

Microscope slides allowed preparations to circulate among scientific and educational contexts. An extension of the circulation of microscope slides was how they became part of lantern exhibition culture. This article considers an early example of the adoption of microscope lantern show conventions by another medium, the cinema. E Martin Duncan, who was employed by Charles Urban to produce a series of popular-science films beginning in 1903, brought his experience with microphotography to bear on the challenge of adapting cinema to the purpose of public instruction. Duncan's first series of films, entitled "The Unseen World," demonstrated both profound links to the display tradition of the lantern lecture as well as the transformation of that tradition by the cinema's representational possibilities.

Turning Microscopy in the Medical Curriculum Digital: Experiences from The Faculty of Health and Medical Sciences at University of Copenhagen

PubMed Central

Vainer, Ben; Mortensen, Niels Werner; Poulsen, Steen Seier; Sørensen, Allan Have; Olsen, Jørgen; Saxild, Hans Henrik; Johansen, Flemming Fryd

2017-01-01

Familiarity with the structure and composition of normal tissue and an understanding of the changes that occur during disease is pivotal to the study of the human body. For decades, microscope slides have been central to teaching pathology in medical courses and related subjects at the University of Copenhagen. Students had to learn how to use a microscope and envisage three-dimensional processes that occur in the body from two-dimensional glass slides. Here, we describe how a PathXL virtual microscopy system for teaching pathology and histology at the Faculty has recently been implemented, from an administrative, an economic, and a teaching perspective. This fully automatic digital microscopy system has been received positively by both teachers and students, and a decision was made to convert all courses involving microscopy to the virtual microscopy format. As a result, conventional analog microscopy will be phased out from the fall of 2016. PMID:28382225

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…

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.

Historical roots of centrosome research: discovery of Boveri's microscope slides in Würzburg

PubMed Central

Scheer, Ulrich

2014-01-01

Boveri's visionary monograph ‘Ueber die Natur der Centrosomen’ (On the nature of centrosomes) in 1900 was founded primarily on microscopic observations of cleaving eggs of sea urchins and the roundworm parasite Ascaris. As Boveri wrote in the introductory paragraph, his interests were less about morphological aspects of centrosomes, but rather aimed at an understanding of their physiological role during cell division. The remarkable transition from observations of tiny dot-like structures in fixed and sectioned material to a unified theory of centrosome function (which in essence still holds true today) cannot be fully appreciated without examining Boveri's starting material, the histological specimens. It was generally assumed that the microscope slides were lost during the bombing of the Zoological Institute in Würzburg at the end of WWII. Here, I describe the discovery of a number of Boveri's original microscope slides with serial sections of early sea urchin and Ascaris embryos, stained by Heidenhain's iron haematoxylin method. Some slides bear handwritten notes and sketches by Boveri. Evidence is presented that the newly discovered slides are part of the original material used by Boveri for his seminal centrosome monograph. PMID:25047623

Analysis of slide exploration strategy of cytologists when reading digital slides

NASA Astrophysics Data System (ADS)

Pantanowitz, Liron; Parwani, Anil; Tseytlin, Eugene; Mello-Thoms, Claudia

2012-02-01

Cytology is the sub-domain of Pathology that deals mainly with the diagnosis of cellular changes caused by disease. Current clinical practice involves a cytotechnologist that manually screens glass slides containing fixed cytology material using a light microscope. Screened slides are then forwarded to a specialized pathologist, a cytopathologist, for microscopic review and final diagnostic interpretation. If no abnormalities are detected, the specimen is interpreted as "normal", otherwise the abnormalities are marked with a pen on the glass slide by the cytotechnologist and then are used to render a diagnosis. As Pathology is migrating towards a digital environment it is important to determine whether these crucial screening and diagnostic tasks can be performed as well using digital slides as the current practice with glass slides. The purpose of this work is to make this assessment, by using a set of digital slides depicting cytological materials of different disease processes in several organs, and then to analyze how different cytologists including cytotechnologists, cytopathologists and cytotechnology-trainees explored the digital slides. We will (1) collect visual search data from the cytologists as they navigate the digital slides, as well as record any electronic marks (annotations) made by the cytologists; (2) convert the dynamic visual search data into a static representation of the observers' exploration strategy using 'search maps'; and (3) determine slide coverage, per viewing magnification range, for each group. We have developed a virtual microscope to collect this data, and this interface allows for interactive navigation of the virtual slide (including panning and zooming), as well as annotation of reportable findings. Furthermore, all interactions with the interface are time stamped, which allows us to recreate the cytologists' search strategy.

Continuous stacking computational approach based automated microscope slide scanner

NASA Astrophysics Data System (ADS)

Murali, Swetha; Adhikari, Jayesh Vasudeva; Jagannadh, Veerendra Kalyan; Gorthi, Sai Siva

2018-02-01

Cost-effective and automated acquisition of whole slide images is a bottleneck for wide-scale deployment of digital pathology. In this article, a computation augmented approach for the development of an automated microscope slide scanner is presented. The realization of a prototype device built using inexpensive off-the-shelf optical components and motors is detailed. The applicability of the developed prototype to clinical diagnostic testing is demonstrated by generating good quality digital images of malaria-infected blood smears. Further, the acquired slide images have been processed to identify and count the number of malaria-infected red blood cells and thereby perform quantitative parasitemia level estimation. The presented prototype would enable cost-effective deployment of slide-based cyto-diagnostic testing in endemic areas.

Fostering Student Engagement with Digital Microscopic Images Using ThingLink, an Image Annotation Program

ERIC Educational Resources Information Center

Appasamy, Pierette

2018-01-01

The teaching of histology has changed dramatically with virtual microscopy. Fewer students of histology spend significant time viewing slides on a microscope and instead study images available in digital slide sets, generally accessible via the internet. However, students must still be able to correctly identify the defining characteristics of…

Evaluation environment for digital and analog pathology: a platform for validation studies

PubMed Central

Gallas, Brandon D.; Gavrielides, Marios A.; Conway, Catherine M.; Ivansky, Adam; Keay, Tyler C.; Cheng, Wei-Chung; Hipp, Jason; Hewitt, Stephen M.

2014-01-01

Abstract. We present a platform for designing and executing studies that compare pathologists interpreting histopathology of whole slide images (WSIs) on a computer display to pathologists interpreting glass slides on an optical microscope. eeDAP is an evaluation environment for digital and analog pathology. The key element in eeDAP is the registration of the WSI to the glass slide. Registration is accomplished through computer control of the microscope stage and a camera mounted on the microscope that acquires real-time images of the microscope field of view (FOV). Registration allows for the evaluation of the same regions of interest (ROIs) in both domains. This can reduce or eliminate disagreements that arise from pathologists interpreting different areas and focuses on the comparison of image quality. We reduced the pathologist interpretation area from an entire glass slide (10 to 30  mm2) to small ROIs (<50  μm2). We also made possible the evaluation of individual cells. We summarize eeDAP’s software and hardware and provide calculations and corresponding images of the microscope FOV and the ROIs extracted from the WSIs. The eeDAP software can be downloaded from the Google code website (project: eeDAP) as a MATLAB source or as a precompiled stand-alone license-free application. PMID:26158076

Evaluation environment for digital and analog pathology: a platform for validation studies.

PubMed

Gallas, Brandon D; Gavrielides, Marios A; Conway, Catherine M; Ivansky, Adam; Keay, Tyler C; Cheng, Wei-Chung; Hipp, Jason; Hewitt, Stephen M

2014-10-01

We present a platform for designing and executing studies that compare pathologists interpreting histopathology of whole slide images (WSIs) on a computer display to pathologists interpreting glass slides on an optical microscope. eeDAP is an evaluation environment for digital and analog pathology. The key element in eeDAP is the registration of the WSI to the glass slide. Registration is accomplished through computer control of the microscope stage and a camera mounted on the microscope that acquires real-time images of the microscope field of view (FOV). Registration allows for the evaluation of the same regions of interest (ROIs) in both domains. This can reduce or eliminate disagreements that arise from pathologists interpreting different areas and focuses on the comparison of image quality. We reduced the pathologist interpretation area from an entire glass slide (10 to [Formula: see text]) to small ROIs ([Formula: see text]). We also made possible the evaluation of individual cells. We summarize eeDAP's software and hardware and provide calculations and corresponding images of the microscope FOV and the ROIs extracted from the WSIs. The eeDAP software can be downloaded from the Google code website (project: eeDAP) as a MATLAB source or as a precompiled stand-alone license-free application.

[Whole slide imaging technology: from digitization to online applications].

PubMed

Ameisen, David; Le Naour, Gilles; Daniel, Christel

2012-11-01

As e-health becomes essential to modern care, whole slide images (virtual slides) are now an important clinical, teaching and research tool in pathology. Virtual microscopy consists of digitizing a glass slide by acquiring hundreds of tiles of regions of interest at different zoom levels and assembling them into a structured file. This gigapixel image can then be remotely viewed over a terminal, exactly the way pathologists use a microscope. In this article, we will first describe the key elements of this technology, from the acquisition, using a scanner or a motorized microscope, to the broadcasting of virtual slides through a local or distant viewer over an intranet or Internet connection. As virtual slides are now commonly used in virtual classrooms, clinical data and research databases, we will highlight the main issues regarding its uses in modern pathology. Emphasis will be made on quality assurance policies, standardization and scaling. © 2012 médecine/sciences – Inserm / SRMS.

Fuzzy control system for a remote focusing microscope

NASA Astrophysics Data System (ADS)

Weiss, Jonathan J.; Tran, Luc P.

1992-01-01

Space Station Crew Health Care System procedures require the use of an on-board microscope whose slide images will be transmitted for analysis by ground-based microbiologists. Focusing of microscope slides is low on the list of crew priorities, so NASA is investigating the option of telerobotic focusing controlled by the microbiologist on the ground, using continuous video feedback. However, even at Space Station distances, the transmission time lag may disrupt the focusing process, severely limiting the number of slides that can be analyzed within a given bandwidth allocation. Substantial time could be saved if on-board automation could pre-focus each slide before transmission. The authors demonstrate the feasibility of on-board automatic focusing using a fuzzy logic ruled-based system to bring the slide image into focus. The original prototype system was produced in under two months and at low cost. Slide images are captured by a video camera, then digitized by gray-scale value. A software function calculates an index of 'sharpness' based on gray-scale contrasts. The fuzzy logic rule-based system uses feedback to set the microscope's focusing control in an attempt to maximize sharpness. The systems as currently implemented performs satisfactorily in focusing a variety of slide types at magnification levels ranging from 10 to 1000x. Although feasibility has been demonstrated, the system's performance and usability could be improved substantially in four ways: by upgrading the quality and resolution of the video imaging system (including the use of full color); by empirically defining and calibrating the index of image sharpness; by letting the overall focusing strategy vary depending on user-specified parameters; and by fine-tuning the fuzzy rules, set definitions, and procedures used.

Microscopic validation of whole mouse micro-metastatic tumor imaging agents using cryo-imaging and sliding organ image registration

NASA Astrophysics Data System (ADS)

Liu, Yiqiao; Zhou, Bo; Qutaish, Mohammed; Wilson, David L.

2016-03-01

We created a metastasis imaging, analysis platform consisting of software and multi-spectral cryo-imaging system suitable for evaluating emerging imaging agents targeting micro-metastatic tumor. We analyzed CREKA-Gd in MRI, followed by cryo-imaging which repeatedly sectioned and tiled microscope images of the tissue block face, providing anatomical bright field and molecular fluorescence, enabling 3D microscopic imaging of the entire mouse with single metastatic cell sensitivity. To register MRI volumes to the cryo bright field reference, we used our standard mutual information, non-rigid registration which proceeded: preprocess --> affine --> B-spline non-rigid 3D registration. In this report, we created two modified approaches: mask where we registered locally over a smaller rectangular solid, and sliding organ. Briefly, in sliding organ, we segmented the organ, registered the organ and body volumes separately and combined results. Though sliding organ required manual annotation, it provided the best result as a standard to measure other registration methods. Regularization parameters for standard and mask methods were optimized in a grid search. Evaluations consisted of DICE, and visual scoring of a checkerboard display. Standard had accuracy of 2 voxels in all regions except near the kidney, where there were 5 voxels sliding. After mask and sliding organ correction, kidneys sliding were within 2 voxels, and Dice overlap increased 4%-10% in mask compared to standard. Mask generated comparable results with sliding organ and allowed a semi-automatic process.

How Prior Knowledge and Colour Contrast Interfere Visual Search Processes in Novice Learners: An Eye Tracking Study

ERIC Educational Resources Information Center

Sonmez, Duygu; Altun, Arif; Mazman, Sacide Guzin

2012-01-01

This study investigates how prior content knowledge and prior exposure to microscope slides on the phases of mitosis effect students' visual search strategies and their ability to differentiate cells that are going through any phases of mitosis. Two different sets of microscope slide views were used for this purpose; with high and low colour…

Reimagining the microscope in the 21(st) century using the scalable adaptive graphics environment.

PubMed

Mateevitsi, Victor; Patel, Tushar; Leigh, Jason; Levy, Bruce

2015-01-01

Whole-slide imaging (WSI), while technologically mature, remains in the early adopter phase of the technology adoption lifecycle. One reason for this current situation is that current methods of visualizing and using WSI closely follow long-existing workflows for glass slides. We set out to "reimagine" the digital microscope in the era of cloud computing by combining WSI with the rich collaborative environment of the Scalable Adaptive Graphics Environment (SAGE). SAGE is a cross-platform, open-source visualization and collaboration tool that enables users to access, display and share a variety of data-intensive information, in a variety of resolutions and formats, from multiple sources, on display walls of arbitrary size. A prototype of a WSI viewer app in the SAGE environment was created. While not full featured, it enabled the testing of our hypothesis that these technologies could be blended together to change the essential nature of how microscopic images are utilized for patient care, medical education, and research. Using the newly created WSI viewer app, demonstration scenarios were created in the patient care and medical education scenarios. This included a live demonstration of a pathology consultation at the International Academy of Digital Pathology meeting in Boston in November 2014. SAGE is well suited to display, manipulate and collaborate using WSIs, along with other images and data, for a variety of purposes. It goes beyond how glass slides and current WSI viewers are being used today, changing the nature of digital pathology in the process. A fully developed WSI viewer app within SAGE has the potential to encourage the wider adoption of WSI throughout pathology.

Reimagining the microscope in the 21st century using the scalable adaptive graphics environment

PubMed Central

Mateevitsi, Victor; Patel, Tushar; Leigh, Jason; Levy, Bruce

2015-01-01

Background: Whole-slide imaging (WSI), while technologically mature, remains in the early adopter phase of the technology adoption lifecycle. One reason for this current situation is that current methods of visualizing and using WSI closely follow long-existing workflows for glass slides. We set out to “reimagine” the digital microscope in the era of cloud computing by combining WSI with the rich collaborative environment of the Scalable Adaptive Graphics Environment (SAGE). SAGE is a cross-platform, open-source visualization and collaboration tool that enables users to access, display and share a variety of data-intensive information, in a variety of resolutions and formats, from multiple sources, on display walls of arbitrary size. Methods: A prototype of a WSI viewer app in the SAGE environment was created. While not full featured, it enabled the testing of our hypothesis that these technologies could be blended together to change the essential nature of how microscopic images are utilized for patient care, medical education, and research. Results: Using the newly created WSI viewer app, demonstration scenarios were created in the patient care and medical education scenarios. This included a live demonstration of a pathology consultation at the International Academy of Digital Pathology meeting in Boston in November 2014. Conclusions: SAGE is well suited to display, manipulate and collaborate using WSIs, along with other images and data, for a variety of purposes. It goes beyond how glass slides and current WSI viewers are being used today, changing the nature of digital pathology in the process. A fully developed WSI viewer app within SAGE has the potential to encourage the wider adoption of WSI throughout pathology. PMID:26110092

A novel method for preparing histology slides to integrate the teaching of gross and microscopic anatomy.

PubMed

Provo-Klimek, Judy A; Troyer, Deryl L

2002-01-01

The authors have previously reported the development of a novel technique for sampling and preparing tissue slides for routine microscopic examination, without the use of a microtome. Termed "RAMP" (Rapid Adhesive Mediated Procedure), this simple, albeit somewhat crude, technique holds promise as a method that can be used in the field by veterinary practitioners for rapid microscopic evaluations to obtain early preliminary estimates of the nature of a mass or lesion. We incorporated the use of this method into a gross anatomy course in an attempt to gauge its utility for novices in tissue sampling and histology slide preparation. By having each group of students take a tissue sample from their cadaver, the activity simulated an actual necropsy situation in which practitioners in the field might use the technique. Because students were able to follow their specimen from sampling to microscopic examination, the activity provided a valuable integration of their learning of gross and microscopic anatomy. We conducted an evaluation of the process and the resulting slides with two successive classes of students. We conclude that the RAMP method is reasonably successful in the hands of individuals not trained in tissue preparation; was well received by the students as a valuable learning tool; and could potentially yield useful histological information for practicing veterinarians. Limitations of the method are also discussed.

Automated clinical system for chromosome analysis

NASA Technical Reports Server (NTRS)

Castleman, K. R.; Friedan, H. J.; Johnson, E. T.; Rennie, P. A.; Wall, R. J. (Inventor)

1978-01-01

An automatic chromosome analysis system is provided wherein a suitably prepared slide with chromosome spreads thereon is placed on the stage of an automated microscope. The automated microscope stage is computer operated to move the slide to enable detection of chromosome spreads on the slide. The X and Y location of each chromosome spread that is detected is stored. The computer measures the chromosomes in a spread, classifies them by group or by type and also prepares a digital karyotype image. The computer system can also prepare a patient report summarizing the result of the analysis and listing suspected abnormalities.

Microscopic validation of whole mouse micro-metastatic tumor imaging agents using cryo-imaging and sliding organ image registration.

PubMed

Liu, Yiqiao; Zhou, Bo; Qutaish, Mohammed; Wilson, David L

2016-01-01

We created a metastasis imaging, analysis platform consisting of software and multi-spectral cryo-imaging system suitable for evaluating emerging imaging agents targeting micro-metastatic tumor. We analyzed CREKA-Gd in MRI, followed by cryo-imaging which repeatedly sectioned and tiled microscope images of the tissue block face, providing anatomical bright field and molecular fluorescence, enabling 3D microscopic imaging of the entire mouse with single metastatic cell sensitivity. To register MRI volumes to the cryo bright field reference, we used our standard mutual information, non-rigid registration which proceeded: preprocess → affine → B-spline non-rigid 3D registration. In this report, we created two modified approaches: mask where we registered locally over a smaller rectangular solid, and sliding organ . Briefly, in sliding organ , we segmented the organ, registered the organ and body volumes separately and combined results. Though s liding organ required manual annotation, it provided the best result as a standard to measure other registration methods. Regularization parameters for standard and mask methods were optimized in a grid search. Evaluations consisted of DICE, and visual scoring of a checkerboard display. Standard had accuracy of 2 voxels in all regions except near the kidney, where there were 5 voxels sliding. After mask and sliding organ correction, kidneys sliding were within 2 voxels, and Dice overlap increased 4%-10% in mask compared to standard . Mask generated comparable results with sliding organ and allowed a semi-automatic process.

Learning pathology using collaborative vs. individual annotation of whole slide images: a mixed methods trial.

PubMed

Sahota, Michael; Leung, Betty; Dowdell, Stephanie; Velan, Gary M

2016-12-12

Students in biomedical disciplines require understanding of normal and abnormal microscopic appearances of human tissues (histology and histopathology). For this purpose, practical classes in these disciplines typically use virtual microscopy, viewing digitised whole slide images in web browsers. To enhance engagement, tools have been developed to enable individual or collaborative annotation of whole slide images within web browsers. To date, there have been no studies that have critically compared the impact on learning of individual and collaborative annotations on whole slide images. Junior and senior students engaged in Pathology practical classes within Medical Science and Medicine programs participated in cross-over trials of individual and collaborative annotation activities. Students' understanding of microscopic morphology was compared using timed online quizzes, while students' perceptions of learning were evaluated using an online questionnaire. For senior medical students, collaborative annotation of whole slide images was superior for understanding key microscopic features when compared to individual annotation; whilst being at least equivalent to individual annotation for junior medical science students. Across cohorts, students agreed that the annotation activities provided a user-friendly learning environment that met their flexible learning needs, improved efficiency, provided useful feedback, and helped them to set learning priorities. Importantly, these activities were also perceived to enhance motivation and improve understanding. Collaborative annotation improves understanding of microscopic morphology for students with sufficient background understanding of the discipline. These findings have implications for the deployment of annotation activities in biomedical curricula, and potentially for postgraduate training in Anatomical Pathology.

Operando formation of an ultra-low friction boundary film from synthetic magnesium silicon hydroxide additive

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

Chang, Qiuying; Rudenko, Pavlo; Miller, Dean J.

The paper reports the operando and self-healing formation of DLC films at sliding contact surfaces by the addition of synthetic magnesium silicon hydroxide (MSH) nanoparticles to base oil. The formation of such films leads to a reduction of the coefficient of friction by nearly an order of magnitude and substantially reduces wear losses. The ultralow friction layer characterized by transmission electron microscope (TEM), electron energy loss spectroscopy (EELS), and Raman spectroscopy consists of amorphous DLC containing SiOx that forms in a continuous and self-repairing manner during operation. This environmentally benign and simple approach offers promise for significant advances in lubricationmore » and reduced energy losses in engines and other mechanical systems.« less

A novel glass slide filing system for pathology slides.

PubMed

Tsai, Steve; Kartono, Francisca; Shitabata, Paul K

2007-07-01

The availability of a collection of microscope glass slides for review is essential in the study and practice of pathology. A common problem facing many pathologists is the lack of a well-organized filing system. We present a novel system that would be easily accessible, informative, protective, and portable.

eeDAP: An Evaluation Environment for Digital and Analog Pathology.

PubMed

Gallas, Brandon D; Cheng, Wei-Chung; Gavrielides, Marios A; Ivansky, Adam; Keay, Tyler; Wunderlich, Adam; Hipp, Jason; Hewitt, Stephen M

2014-01-01

The purpose of this work is to present a platform for designing and executing studies that compare pathologists interpreting histopathology of whole slide images (WSI) on a computer display to pathologists interpreting glass slides on an optical microscope. Here we present eeDAP, an evaluation environment for digital and analog pathology. The key element in eeDAP is the registration of the WSI to the glass slide. Registration is accomplished through computer control of the microscope stage and a camera mounted on the microscope that acquires images of the real time microscope view. Registration allows for the evaluation of the same regions of interest (ROIs) in both domains. This can reduce or eliminate disagreements that arise from pathologists interpreting different areas and focuses the comparison on image quality. We reduced the pathologist interpretation area from an entire glass slide (≈10-30 mm) 2 to small ROIs <(50 um) 2 . We also made possible the evaluation of individual cells. We summarize eeDAP's software and hardware and provide calculations and corresponding images of the microscope field of view and the ROIs extracted from the WSIs. These calculations help provide a sense of eeDAP's functionality and operating principles, while the images provide a sense of the look and feel of studies that can be conducted in the digital and analog domains. The eeDAP software can be downloaded from code.google.com (project: eeDAP) as Matlab source or as a precompiled stand-alone license-free application.

Effect of Physicochemical Anomalies of Soda-Lime Silicate Slides on Biomolecule Immobilization

DTIC Science & Technology

2009-01-01

roughness. EXPERIMENTAL SECTION Materials. Standard soda - lime glass microscope slides were obtained from several sources (Table 1). Rabbit anti-lipid A...had changed, confir- mation was obtained from the manufacturers that slides in set A1 were the same soda - lime glass slides as those in set A2 and...manufacture of soda - lime glass slides. X-ray Photoelectron Spectroscopy (XPS). To identify el- emental disparities in the glass surface, relative atomic

Superlubricity of a Mixed Aqueous Solution

NASA Astrophysics Data System (ADS)

Ma, Zhi-Zuo; Zhang, Chen-Hui; Luo, Jian-Bin; Lu, Xin-Chun; Wen, Shi-Zhu

2011-05-01

A super-low friction coefficient of 0.0028 is measured under a pressure of 300 MPa when the friction pair (the silicon nitride ball sliding on the silicate glass) is lubricated by the mixed aqueous solution of glycerol and boric acid. The morphorlogies of the hydroxylated glass plate are observed by an atomic force microscope (AFM) in deionized water, glycerol, boric acid and their mixed aqueous solution. Bonding peaks of the retained liquids adhered on the surface of the sliding track are detected by an infrared spectrum apparatus and a Raman spectrum apparatus. The mechanism of the superlubricity of the glycerol and boric acid mixed aqueous solution is discussed. It is deduced that the formation of the lubricant film has enough strength to support higher loads, the hydration effect offering the super lower shear resistance. Key words: superlubricity, water based lubricant, ultra-low friction

Whole-slide imaging in pathology: the potential impact on PACS

NASA Astrophysics Data System (ADS)

Horii, Steven C.

2007-03-01

Pathology, the medical specialty charged with the evaluation of macroscopic and microscopic aspects of disease, is increasingly turning to digital imaging. While the conventional tissue blocks and glass slides form an "archive" that pathology departments must maintain, digital images acquired from microscopes or digital slide scanners are increasingly used for telepathology, consultation, and intra-facility communication. Since many healthcare facilities are moving to "enterprise PACS" with departments in addition to radiology using the infrastructure of such systems, some understanding of the potential of whole-slide digital images is important. Network and storage designers, in particular, are very likely to be impacted if a significant number of such images are to be moved on, or stored (even temporarily) in, enterprise PACS. As an example, a typical commercial whole-slide imaging system typically generates 15 gigabytes per slide scanned (per focal plane). Many of these whole-slide scanners have a throughput of 1000 slides per day. If that full capacity is used and all the resulting digital data is moved to the enterprise PACS, it amounts to 15 terabytes per day; the amount of data a large radiology department might generate in a year or two. This paper will review both the clinical scenarios of whole-slide imaging as well as the resulting data volumes. The author will emphasize the potential PACS infrastructure impact of such huge data volumes.

Quantitative Imaging In Pathology (QUIP) | Informatics Technology for Cancer Research (ITCR)

Cancer.gov

This site hosts web accessible applications, tools and data designed to support analysis, management, and exploration of whole slide tissue images for cancer research. The following tools are included: caMicroscope: A digital pathology data management and visualization plaform that enables interactive viewing of whole slide tissue images and segmentation results. caMicroscope can be also used independently of QUIP. FeatureExplorer: An interactive tool to allow patient-level feature exploration across multiple dimensions.

Plastic deformation at surface during unlubricated sliding

NASA Technical Reports Server (NTRS)

Yamamoto, T.; Buckley, D. H.

1982-01-01

The plastic deformation and wear of 304 stainless-steel surface slid against an aluminum oxide rider were observed by using a scanning electron microscope and an optical microscope. Experiments were conducted in a vacuum of 0.000001 Pa and in an environment of 0.0005 Pa chlorine gas at 25 C. The load was 500 grams and the sliding velocity was 0.5 centimeter per second. The deformed surface layer which accumulates and develops successively is left behind the rider, and step-shaped protuberances are developed even after single pass sliding under both environmental conditions. A fully developed surface layer is gradually torn off leaving a characteristic pattern. These observations result from both adhesion and an adhesive wear mechanism.

eeDAP: An Evaluation Environment for Digital and Analog Pathology

PubMed Central

Gallas, Brandon D.; Cheng, Wei-Chung; Gavrielides, Marios A.; Ivansky, Adam; Keay, Tyler; Wunderlich, Adam; Hipp, Jason; Hewitt, Stephen M.

2017-01-01

Purpose The purpose of this work is to present a platform for designing and executing studies that compare pathologists interpreting histopathology of whole slide images (WSI) on a computer display to pathologists interpreting glass slides on an optical microscope. Methods Here we present eeDAP, an evaluation environment for digital and analog pathology. The key element in eeDAP is the registration of the WSI to the glass slide. Registration is accomplished through computer control of the microscope stage and a camera mounted on the microscope that acquires images of the real time microscope view. Registration allows for the evaluation of the same regions of interest (ROIs) in both domains. This can reduce or eliminate disagreements that arise from pathologists interpreting different areas and focuses the comparison on image quality. Results We reduced the pathologist interpretation area from an entire glass slide (≈10–30 mm)2 to small ROIs <(50 um)2. We also made possible the evaluation of individual cells. Conclusions We summarize eeDAP’s software and hardware and provide calculations and corresponding images of the microscope field of view and the ROIs extracted from the WSIs. These calculations help provide a sense of eeDAP’s functionality and operating principles, while the images provide a sense of the look and feel of studies that can be conducted in the digital and analog domains. The eeDAP software can be downloaded from code.google.com (project: eeDAP) as Matlab source or as a precompiled stand-alone license-free application. PMID:28845079

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.

Optical Properties of Silver Nanoparticulate Glasses

NASA Astrophysics Data System (ADS)

Evans, Rachel N.; Cannavino, Sarah A.; King, Christy A.; Lamartina, Joseph A.; Magruder, Robert H.; Ferrara, Davon W.

The ion exchange method of embedding metal nanoparticles (NPs) into float glass is an often used technique of fabricating colored glasses and graded-index waveguides. The depth and size of NP formation in the glass depends on the concentration and temperature of metal ions in the molten bath. In this study we explore the dichroic properties of silver metal ion exchange restricted to only one side of a glass microscope slide using reflection and transmission spectroscopy and its dependence on temperature, concentration of silver ions, and length of time in the molten bath.

Manual stage acquisition and interactive display of digital slides in histopathology.

PubMed

Gherardi, Alessandro; Bevilacqua, Alessandro

2014-07-01

More powerful PC architectures, high-resolution cameras working at increasing frame rates, and more and more accurate motorized microscopes have boosted new applications in the field of biomedicine and medical imaging. In histopathology, the use of digital slides (DSs) imaging through dedicated hardware for digital pathology is increasing for several reasons: digital annotation of suspicious lesions, recorded clinical history, and telepathology as a collaborative environment. In this paper, we propose the first method known in the literature for real-time whole slide acquisition and displaying conceived for conventional nonautomated microscopes. Differently from DS scanner, our software enables biologists and histopathologists to build and view the DS in real time while inspecting the sample, as they are accustomed to. In addition, since our approach is compliant with existing common microscope positions, provided with camera and PC, this could contribute to disseminate the whole slide technology in the majority of small labs not endowed with DS hardware facilities. Experiments performed with different histologic specimens (referring to tumor tissues of different body parts as well as to tumor cells), acquired under different setup conditions and devices, prove the effectiveness of our approach both in terms of quality and speed performances.

Performance of a malaria microscopy image analysis slide reading device.

PubMed

Prescott, William R; Jordan, Robert G; Grobusch, Martin P; Chinchilli, Vernon M; Kleinschmidt, Immo; Borovsky, Joseph; Plaskow, Mark; Torrez, Miguel; Mico, Maximo; Schwabe, Christopher

2012-05-06

Viewing Plasmodium in Romanovsky-stained blood has long been considered the gold standard for diagnosis and a cornerstone in management of the disease. This method however, requires a subjective evaluation by trained, experienced diagnosticians and establishing proficiency of diagnosis is fraught with many challenges. Reported here is an evaluation of a diagnostic system (a "device" consisting of a microscope, a scanner, and a computer algorithm) that evaluates scanned images of standard Giemsa-stained slides and reports species and parasitaemia. The device was challenged with two independent tests: a 55 slide, expert slide reading test the composition of which has been published by the World Health Organization ("WHO55" test), and a second test in which slides were made from a sample of consenting subjects participating in a malaria incidence survey conducted in Equatorial Guinea (EGMIS test). These subjects' blood was tested by malaria RDT as well as having the blood smear diagnosis unequivocally determined by a worldwide panel of a minimum of six reference microscopists. Only slides with unequivocal microscopic diagnoses were used for the device challenge, n = 119. On the WHO55 test, the device scored a "Level 4" using the WHO published grading scheme. Broken down by more traditional analysis parameters this result was translated to 89% and 70% sensitivity and specificity, respectively. Species were correctly identified in 61% of the slides and the quantification of parasites fell within acceptable range of the validated parasitaemia in 10% of the cases. On the EGMIS test it scored 100% and 94% sensitivity/specificity, with 64% of the species correct and 45% of the parasitaemia within an acceptable range. A pooled analysis of the 174 slides used for both tests resulted in an overall 92% sensitivity and 90% specificity with 61% species and 19% quantifications correct. In its current manifestation, the device performs at a level comparable to that of many human slide readers. Because its use requires minimal additional equipment and it uses standard stained slides as starting material, its widespread adoption may eliminate the current uncertainty about the quality of microscopic diagnoses worldwide.

Performance of a malaria microscopy image analysis slide reading device

PubMed Central

2012-01-01

Background Viewing Plasmodium in Romanovsky-stained blood has long been considered the gold standard for diagnosis and a cornerstone in management of the disease. This method however, requires a subjective evaluation by trained, experienced diagnosticians and establishing proficiency of diagnosis is fraught with many challenges. Reported here is an evaluation of a diagnostic system (a “device” consisting of a microscope, a scanner, and a computer algorithm) that evaluates scanned images of standard Giemsa-stained slides and reports species and parasitaemia. Methods The device was challenged with two independent tests: a 55 slide, expert slide reading test the composition of which has been published by the World Health Organization (“WHO55” test), and a second test in which slides were made from a sample of consenting subjects participating in a malaria incidence survey conducted in Equatorial Guinea (EGMIS test). These subjects’ blood was tested by malaria RDT as well as having the blood smear diagnosis unequivocally determined by a worldwide panel of a minimum of six reference microscopists. Only slides with unequivocal microscopic diagnoses were used for the device challenge, n = 119. Results On the WHO55 test, the device scored a “Level 4” using the WHO published grading scheme. Broken down by more traditional analysis parameters this result was translated to 89% and 70% sensitivity and specificity, respectively. Species were correctly identified in 61% of the slides and the quantification of parasites fell within acceptable range of the validated parasitaemia in 10% of the cases. On the EGMIS test it scored 100% and 94% sensitivity/specificity, with 64% of the species correct and 45% of the parasitaemia within an acceptable range. A pooled analysis of the 174 slides used for both tests resulted in an overall 92% sensitivity and 90% specificity with 61% species and 19% quantifications correct. Conclusions In its current manifestation, the device performs at a level comparable to that of many human slide readers. Because its use requires minimal additional equipment and it uses standard stained slides as starting material, its widespread adoption may eliminate the current uncertainty about the quality of microscopic diagnoses worldwide. PMID:22559294

Boveri's research at the Zoological Station Naples: Rediscovery of his original microscope slides at the University of Würzburg.

PubMed

Scheer, Ulrich

2018-02-14

Eric Davidson once wrote about Theodor Boveri: "From his own researches, and perhaps most important, his generalized interpretations, derive the paradigms that underlie modern inquiries into the genomic basis of embryogenesis" (Davidson, 1985). As luck would have it, the "primary data" of Boveri's experimental work, namely the microscope slides prepared by him and his wife Marcella during several stays at the Zoological Station in Naples (1901/02, 1911/12 and 1914), have survived at the University of Würzburg. More than 600 slides exist and despite their age they are in a surprisingly good condition. The slides are labelled and dated in Boveri's handwriting and thus can be assigned to his published experimental work on sea urchin development. The results allowed Boveri to unravel the role of the cell nucleus and its chromosomes in development and inheritance. Here, I present an overview of the slides in the context of Boveri's work along with photographic images of selected specimens taken from the original slides. It is planned to examine the slides in more detail, take high-resolution focal image series of significant specimens and make them online available. Copyright © 2018 The Author. Published by Elsevier B.V. All rights reserved.

Modification of the Miyake-Apple technique for simultaneous anterior and posterior video imaging of wet laboratory-based corneal surgery.

PubMed

Tan, Johnson C H; Meadows, Howard; Gupta, Aanchal; Yeung, Sonia N; Moloney, Gregory

2014-03-01

The aim of this study was to describe a modification of the Miyake-Apple posterior video analysis for the simultaneous visualization of the anterior and posterior corneal surfaces during wet laboratory-based deep anterior lamellar keratoplasty (DALK). A human donor corneoscleral button was affixed to a microscope slide and placed onto a custom-made mounting box. A big bubble DALK was performed on the cornea in the wet laboratory. An 11-diopter intraocular lens was positioned over the aperture of the back camera of an iPhone. This served to video record the posterior view of the corneoscleral button during the big bubble formation. An overhead operating microscope with an attached video camcorder recorded the anterior view during the surgery. The anterior and posterior views of the wet laboratory-based DALK surgery were simultaneously captured and edited using video editing software. The formation of the big bubble can be studied. This video recording camera system has the potential to act as a valuable research and teaching tool in corneal lamellar surgery, especially in the behavior of the big bubble formation in DALK.

Active Learning: A Small Group Histology Laboratory Exercise in a Whole Class Setting Utilizing Virtual Slides and Peer Education

ERIC Educational Resources Information Center

Bloodgood, Robert A.

2012-01-01

Histology laboratory instruction is moving away from the sole use of the traditional combination of light microscopes and glass slides in favor of virtual microscopy and virtual slides. At the same time, medical curricula are changing so as to reduce scheduled time for basic science instruction as well as focusing on student-centered learning…

A multiple-well method for immunohistochemical testing of many reagents on a single microscopic slide.

PubMed

McKeever, P E; Letica, L H; Shakui, P; Averill, D R

1988-09-01

Multiple wells (M-wells) have been made over tissue sections on single microscopic slides to simultaneously localize binding specificity of many antibodies. More than 20 individual 4-microliter wells over tissue have been applied/slide, representing more than a 5-fold improvement in wells/slide and a 25-fold reduction in reagent volume over previous methods. More than 30 wells/slide have been applied over cellular monolayers. To produce the improvement, previous strategies of placing specimens into wells were changed to instead create wells over the specimen. We took advantage of the hydrophobic properties of paint to surround the wells and to segregate the various different primary antibodies. Segregation was complete on wells alternating with and without primary monoclonal antibody. The procedure accommodates both frozen and paraffin sections, yielding slides which last more than a year. After monoclonal antibody detection, standard histologic stains can be applied as counterstains. M-wells are suitable for localizing binding of multiple reagents or sample unknowns (polyclonal or monoclonal antibodies, hybridoma supernatants, body fluids, lectins) to either tissues or cells. Their small sample volume and large number of sample wells/slide could be particularly useful for early screening of hybridoma supernatants and for titration curves in immunohistochemistry (McKeever PE, Shakui P, Letica LH, Averill DR: J Histochem Cytochem 36:931, 1988).

Adaptive Localization of Focus Point Regions via Random Patch Probabilistic Density from Whole-Slide, Ki-67-Stained Brain Tumor Tissue

PubMed Central

Alomari, Yazan M.; MdZin, Reena Rahayu

2015-01-01

Analysis of whole-slide tissue for digital pathology images has been clinically approved to provide a second opinion to pathologists. Localization of focus points from Ki-67-stained histopathology whole-slide tissue microscopic images is considered the first step in the process of proliferation rate estimation. Pathologists use eye pooling or eagle-view techniques to localize the highly stained cell-concentrated regions from the whole slide under microscope, which is called focus-point regions. This procedure leads to a high variety of interpersonal observations and time consuming, tedious work and causes inaccurate findings. The localization of focus-point regions can be addressed as a clustering problem. This paper aims to automate the localization of focus-point regions from whole-slide images using the random patch probabilistic density method. Unlike other clustering methods, random patch probabilistic density method can adaptively localize focus-point regions without predetermining the number of clusters. The proposed method was compared with the k-means and fuzzy c-means clustering methods. Our proposed method achieves a good performance, when the results were evaluated by three expert pathologists. The proposed method achieves an average false-positive rate of 0.84% for the focus-point region localization error. Moreover, regarding RPPD used to localize tissue from whole-slide images, 228 whole-slide images have been tested; 97.3% localization accuracy was achieved. PMID:25793010

Standardization of whole slide image morphologic assessment with definition of a new application: Digital slide dynamic morphometry.

PubMed

Puppa, Giacomo; Risio, Mauro; Sheahan, Kieran; Vieth, Michael; Zlobec, Inti; Lugli, Alessandro; Pecori, Sara; Wang, Lai Mun; Langner, Cord; Mitomi, Hiroyuki; Nakamura, Takatoshi; Watanabe, Masahiko; Ueno, Hideki; Chasle, Jacques; Senore, Carlo; Conley, Stephen A; Herlin, Paulette; Lauwers, Gregory Y

2011-01-01

In histopathology, the quantitative assessment of various morphologic features is based on methods originally conceived on specific areas observed through the microscope used. Failure to reproduce the same reference field of view using a different microscope will change the score assessed. Visualization of a digital slide on a screen through a dedicated viewer allows selection of the magnification. However, the field of view is rectangular, unlike the circular field of optical microscopy. In addition, the size of the selected area is not evident, and must be calculated. A digital slide morphometric system was conceived to reproduce the various methods published for assessing tumor budding in colorectal cancer. Eighteen international experts in colorectal cancer were invited to participate in a web-based study by assessing tumor budding with five different methods in 100 digital slides. The specific areas to be tested by each method were marked by colored circles. The areas were grouped in a target-like pattern and then saved as an .xml file. When a digital slide was opened, the .xml file was imported in order to perform the measurements. Since the morphometric tool is composed of layers that can be freely moved on top of the digital slide, the technique was named digital slide dynamic morphometry. Twelve investigators completed the task, the majority of them performing the multiple evaluations of each of the cases in less than 12 minutes. Digital slide dynamic morphometry has various potential applications and might be a useful tool for the assessment of histologic parameters originally conceived for optical microscopy that need to be quantified.

Quantification of Estrogen Receptor-Alpha Expression in Human Breast Carcinomas With a Miniaturized, Low-Cost Digital Microscope: A Comparison with a High-End Whole Slide-Scanner

PubMed Central

Holmström, Oscar; Linder, Nina; Lundin, Mikael; Moilanen, Hannu; Suutala, Antti; Turkki, Riku; Joensuu, Heikki; Isola, Jorma; Diwan, Vinod; Lundin, Johan

2015-01-01

Introduction A significant barrier to medical diagnostics in low-resource environments is the lack of medical care and equipment. Here we present a low-cost, cloud-connected digital microscope for applications at the point-of-care. We evaluate the performance of the device in the digital assessment of estrogen receptor-alpha (ER) expression in breast cancer samples. Studies suggest computer-assisted analysis of tumor samples digitized with whole slide-scanners may be comparable to manual scoring, here we study whether similar results can be obtained with the device presented. Materials and Methods A total of 170 samples of human breast carcinoma, immunostained for ER expression, were digitized with a high-end slide-scanner and the point-of-care microscope. Corresponding regions from the samples were extracted, and ER status was determined visually and digitally. Samples were classified as ER negative (<1% ER positivity) or positive, and further into weakly (1–10% positivity) and strongly positive. Interobserver agreement (Cohen’s kappa) was measured and correlation coefficients (Pearson’s product-momentum) were calculated for comparison of the methods. Results Correlation and interobserver agreement (r = 0.98, p < 0.001, kappa = 0.84, CI95% = 0.75–0.94) were strong in the results from both devices. Concordance of the point-of-care microscope and the manual scoring was good (r = 0.94, p < 0.001, kappa = 0.71, CI95% = 0.61–0.80), and comparable to the concordance between the slide scanner and manual scoring (r = 0.93, p < 0.001, kappa = 0.69, CI95% = 0.60–0.78). Fourteen (8%) discrepant cases between manual and device-based scoring were present with the slide scanner, and 16 (9%) with the point-of-care microscope, all representing samples of low ER expression. Conclusions Tumor ER status can be accurately quantified with a low-cost imaging device and digital image-analysis, with results comparable to conventional computer-assisted or manual scoring. This technology could potentially be expanded for other histopathological applications at the point-of-care. PMID:26659386

Improved resolution in practical light microscopy by means of a glass-fiber 2 π-tilting device

NASA Astrophysics Data System (ADS)

Bradl, Joachim; Rinke, Bernd; Schneider, Bernhard; Hausmann, Michael; Cremer, Christoph G.

1996-01-01

The spatial resolution of a conventional light microscope or a confocal laser scanning microscope can be determined by calculating the point spread function for the objective used. Normally, ideal conditions are assumed for these calculations. Such conditions, however, are often not fulfilled in biological applications especially in those cases where biochemical requirements (e.g. buffer conditions) influence the specimen preparation on the microscope slide (i.e. 'practical' light microscopy). It has been shown that the problem of a reduced z- resolution in 3D-microscopy (optical sectioning) can be overcome by a capillary in a 2(pi) - tilting device that allows object rotation into an optimal perspective. The application of the glass capillary instead of a standard slide has an additional influence on the imaging properties of the microscope. Therefore, another 2(pi) -tilting device was developed, using a glass fiber for object fixation and rotation. Such a fiber could be covered by standard cover glasses. To estimate the resolution of this setup, point spread functions were measured under different conditions using fluorescent microspheres of subwavelength dimensions. Results obtained from standard slide setups were compared to the glass fiber setup. These results showed that in practice rotation leads to an overall 3D-resolution improvement.

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)

EVALUATION OF CONFOCAL MICROSCOPY SYSTEM PERFORMANCE

EPA Science Inventory

BACKGROUND. The confocal laser scanning microscope (CLSM) has enormous potential in many biological fields. Currently there is a subjective nature in the assessment of a confocal microscope's performance by primarily evaluating the system with a specific test slide provided by ea...

Formative Processes of a Sliding Zone in Pelitic Schist - Implications of Microscopic Analyses on High-quality Drilled Cores

NASA Astrophysics Data System (ADS)

Yamasaki, S.; Chigira, M.

2009-04-01

Pelitic schist has been known to be easily deformed by gravitational force to form characteristic topographic and geologic features, but little is known about how they develop. This is mainly due to the fact that deformed politic schist is so fragile that it could not be obtained from subsurface without disturbance. We analyzed high-quality undisturbed cores obtained by using a sophisticated drilling technique from two typical pelitic schist landslide sites in Japan. We made analyses on physical, chemical, mineralogical properties and observations from mesoscopic to microscopic rock textures of these cores and found that a special layering of rock-forming minerals determines the locations of shearing by gravity and that there is specific water-rock interaction processes in pelitic schist. Pelitic schist consists of thinly alternating beds of black layers and quartz-rich layers, and a black layer has numerous microscopic layers containing abundant pyrite and graphite grains (pyrite-graphite layers). Many of the black layers were observed to have microfractures connected to open cracks, suggesting that relatively thick, continuous black layers are easily sheared to form an incipient sliding layer. Thus unevenly distributed pyrite-graphite layers likely to determine the potential location of microscopic slip in a rock mass. Shear displacement along black layers occurs unevenly, depending upon the microscopic heterogeneity in mineral composition as well as undulating shape of the layers. Open micro-cracks nearly perpendicular to the schistosity were commonly observed in quartz-rich layers in contact with black layers, suggesting that the shearing occurred with heterogeneous displacements along the black layer and that it occurred under the low confining pressure. This is in the incipient stage of a fracture zone. When shearing occurs along two thick neighboring black layers, the rock in between would be fractured, rotated and pulverized. In some cases, quartz-rich layers were fractured in a brittle manner and their fragments were rearranged to form micro-folds. Rocks are thus pulverized with multiple shear surfaces. Incipient fracture zones and their surroundings have many voids because they are made under low confining pressures near the ground surface, so oxidizing surface water easily percolates through them. Oxidizing water reacts with pyrite which is contained in pelitic schist, producing sulfuric acid through. The rocks therefore become deteriorated by the water-rock interaction and would be easily deformed. Such a combination of the physical processes of deformation and fracturing and the chemical process of weathering develop a sliding zone.

Comparing whole slide digital images versus traditional glass slides in the detection of common microscopic features seen in dermatitis

PubMed Central

Vyas, Nikki S.; Markow, Michael; Prieto-Granada, Carlos; Gaudi, Sudeep; Turner, Leslie; Rodriguez-Waitkus, Paul; Messina, Jane L.; Jukic, Drazen M.

2016-01-01

Background: The quality and limitations of digital slides are not fully known. We aimed to estimate intrapathologist discrepancy in detecting specific microscopic features on glass slides and digital slides created by scanning at ×20. Methods: Hematoxylin and eosin and periodic acid–Schiff glass slides were digitized using the Mirax Scan (Carl Zeiss Inc., Germany). Six pathologists assessed 50–71 digital slides. We recorded objective magnification, total time, and detection of the following: Mast cells; eosinophils; plasma cells; pigmented macrophages; melanin in the epidermis; fungal bodies; neutrophils; civatte bodies; parakeratosis; and sebocytes. This process was repeated using the corresponding glass slides after 3 weeks. The diagnosis was not required. Results: The mean time to assess digital slides was 176.77 s and 137.61 s for glass slides (P < 0.001, 99% confidence interval [CI]). The mean objective magnification used to detect features using digital slides was 18.28 and 14.07 for glass slides (P < 0.001, 99.99% CI). Parakeratosis, civatte bodies, pigmented macrophages, melanin in the epidermis, mast cells, eosinophils, plasma cells, and neutrophils, were identified at lower objectives on glass slides (P = 0.023–0.001, 95% CI). Average intraobserver concordance ranged from κ = 0.30 to κ = 0.78. Features with poor to fair average concordance were: Melanin in the epidermis (κ = 0.15–0.58); plasma cells (κ = 0.15–0.49); and neutrophils (κ = 0.12–0.48). Features with moderate average intrapathologist concordance were: parakeratosis (κ = 0.21–0.61); civatte bodies (κ = 0.21–0.71); pigment-laden macrophages (κ = 0.34–0.66); mast cells (κ = 0.29–0.78); and eosinophils (κ = 0.31–0.79). The average intrapathologist concordance was good for sebocytes (κ = 0.51–1.00) and fungal bodies (κ = 0.47–0.76). Conclusions: Telepathology using digital slides scanned at ×20 is sufficient for detection of histopathologic features routinely encountered in dermatitis cases, though less efficient than glass slides. PMID:27563489

A method for reducing the sloughing of thick blood films for malaria diagnosis.

PubMed

Norgan, Andrew P; Arguello, Heather E; Sloan, Lynne M; Fernholz, Emily C; Pritt, Bobbi S

2013-07-08

The gold standard for malaria diagnosis is the examination of thick and thin blood films. Thick films contain 10 to 20 times more blood than thin films, correspondingly providing increased sensitivity for malaria screening. A potential complication of thick film preparations is sloughing of the blood droplet from the slide during staining or rinsing, resulting in the loss of sample. In this work, two methods for improving thick film slide adherence ('scratch' (SCM) and 'acetone dip' (ADM) methods) were compared to the 'standard method' (SM) of thick film preparation. Standardized blood droplets from 26 previously examined EDTA whole blood specimens (22 positive and four negative) were concurrently spread on glass slides using the SM, ADM, and SCM. For the SM and ADM prepared slides, the droplet was gently spread to an approximate 22 millimeters in diameter spot on the slide using the edge of a second glass slide. For the SCM, the droplet was spread by carefully grinding (or scratching) it into the slide with the point of a second glass slide. Slides were dried for one hour in a laminar flow hood. For the ADM, slides were dipped once in an acetone filled Coplin jar and allowed to air dry. All slides were then Giemsa-stained and examined in a blinded manner. Adherence was assessed by blinded reviewers. No significant or severe defects were observed for slides prepared with the SCM. In contrast, 8 slides prepared by the ADM and 3 prepared using the SM displayed significant or severe defects. Thick films prepared by the three methods were microscopically indistinguishable and concordant results (positive or negative) were obtained for the three methods. Estimated parasitaemia of the blood samples ranged from 25 to 429,169 parasites/μL of blood. The SCM is an inexpensive, rapid, and simple method that improves the adherence of thick blood films to standard glass slides without altering general slide preparation, microscopic appearance or interpretability. Using the SCM, thick films can be reliably examined less than two hours after sample receipt. This represents a significant diagnostic improvement over protocols requiring extended drying periods.

State of the art of teledermatopathology.

PubMed

Massone, Cesare; Brunasso, Alexandra M G; Campbell, Terri M; Soyer, H Peter

2008-10-01

Teledermatopathology may involve real-time transmission of images from distant locations to consulting pathologists by the remote manipulation of a robotic microscope. Alternatively, the static store-and-forward option involves the single-file transmission of subjectively preselected and captured areas of microscopic images by a referring physician. The recent introduction of virtual slide systems (VSS) involves the digitization of whole slides at high resolution thus enabling the user to view any part of the specimen at any magnification. Such technology has surmounted previous restrictions caused by the size of preselected areas and specimen sampling for telepathology. In terms of client access, these VSS may be stored on a virtual slide server, made available on the Web for remote consultation by pathologists via an integrated virtual slide client network. Despite store-and-forward teledermatopathology being the most frequently used and less expensive approach to teledermatopathology, VSS represents the future in this discipline. The recent pilot studies suggest that the use of remote expert consultants in diagnostic dermatopathology can be integrated into daily routine, teleconsultation, and teleteaching. The new technology enables rapid and reproducible diagnoses, but despite its usability, VSS is not completely feasible for teledermatopathology of inflammatory skin diseases as the performance seems to be influenced by the availability of complete clinical data. Improvements in the diagnostic facility will no doubt follow from further development of the VSS, the slide processor, and of course training in the use of virtual microscope. Undoubtedly, as technology becomes even more sophisticated in the future, VSS will overcome the present drawbacks and find its place in all facets of teledermatopathology.

Lubrication and failure mechanisms of molybdenum disulfide films. 1: Effect of atmosphere

NASA Technical Reports Server (NTRS)

Fusaro, R. L.

1978-01-01

Friction, wear, and wear lives of rubbed molybdenum disulfide (MoS2 films applied to sanded 440C HT steel surfaces were evaluated in moist air, dry air, and dry argon. Optical microscope observations were made as a function of sliding distance to determine the effect of moisture and oxygen on the lubricating and failure mechanisms of MoS2 films. In general, the lubrication process consisted of the formation of a thin, metallic colored, coalesced film of MoS2 that flowed between the surfaces in relative motion. In air, failure was due to the transformation of the metallic colored, coalesced films to a black, powdery material. Water in the air appeared to accelerate the transformation rate. In argon, no transformation of MoS2 was observed with the microscope, but cracking and spalling of the coalesced film occurred and resulted in the gradual depletion of the film.

Examining the contents of isolated Xenopus germinal vesicles.

PubMed

Gall, Joseph G; Wu, Zheng'an

2010-05-01

One can manually isolate the giant oocyte nucleus or germinal vesicle (GV) of Xenopus from a living oocyte with nothing more complicated than jewelers' forceps and a dissecting microscope. Similarly, one can remove the nuclear envelope by hand and allow the lampbrush chromosomes and other nuclear organelles to spread on a microscope slide. After centrifugation, the nuclear contents adhere tightly to the slide, where they can be subjected to immunostaining or fluorescent in situ hybridization for visualization by conventional or confocal microscopy. Preparations of isolated GV contents reveal details of nuclear structure that are almost impossible to attain by more conventional techniques.

DeepScope: Nonintrusive Whole Slide Saliency Annotation and Prediction from Pathologists at the Microscope

PubMed Central

Schaumberg, Andrew J.; Sirintrapun, S. Joseph; Al-Ahmadie, Hikmat A.; Schüffler, Peter J.; Fuchs, Thomas J.

2018-01-01

Modern digital pathology departments have grown to produce whole-slide image data at petabyte scale, an unprecedented treasure chest for medical machine learning tasks. Unfortunately, most digital slides are not annotated at the image level, hindering large-scale application of supervised learning. Manual labeling is prohibitive, requiring pathologists with decades of training and outstanding clinical service responsibilities. This problem is further aggravated by the United States Food and Drug Administration’s ruling that primary diagnosis must come from a glass slide rather than a digital image. We present the first end-to-end framework to overcome this problem, gathering annotations in a nonintrusive manner during a pathologist’s routine clinical work: (i) microscope-specific 3D-printed commodity camera mounts are used to video record the glass-slide-based clinical diagnosis process; (ii) after routine scanning of the whole slide, the video frames are registered to the digital slide; (iii) motion and observation time are estimated to generate a spatial and temporal saliency map of the whole slide. Demonstrating the utility of these annotations, we train a convolutional neural network that detects diagnosis-relevant salient regions, then report accuracy of 85.15% in bladder and 91.40% in prostate, with 75.00% accuracy when training on prostate but predicting in bladder, despite different pathologists examining the different tissues. When training on one patient but testing on another, AUROC in bladder is 0.79±0.11 and in prostate is 0.96±0.04. Our tool is available at https://bitbucket.org/aschaumberg/deepscope PMID:29601065

Comparison of the manual, semiautomatic, and automatic selection and leveling of hot spots in whole slide images for Ki-67 quantification in meningiomas.

PubMed

Swiderska, Zaneta; Korzynska, Anna; Markiewicz, Tomasz; Lorent, Malgorzata; Zak, Jakub; Wesolowska, Anna; Roszkowiak, Lukasz; Slodkowska, Janina; Grala, Bartlomiej

2015-01-01

Background. This paper presents the study concerning hot-spot selection in the assessment of whole slide images of tissue sections collected from meningioma patients. The samples were immunohistochemically stained to determine the Ki-67/MIB-1 proliferation index used for prognosis and treatment planning. Objective. The observer performance was examined by comparing results of the proposed method of automatic hot-spot selection in whole slide images, results of traditional scoring under a microscope, and results of a pathologist's manual hot-spot selection. Methods. The results of scoring the Ki-67 index using optical scoring under a microscope, software for Ki-67 index quantification based on hot spots selected by two pathologists (resp., once and three times), and the same software but on hot spots selected by proposed automatic methods were compared using Kendall's tau-b statistics. Results. Results show intra- and interobserver agreement. The agreement between Ki-67 scoring with manual and automatic hot-spot selection is high, while agreement between Ki-67 index scoring results in whole slide images and traditional microscopic examination is lower. Conclusions. The agreement observed for the three scoring methods shows that automation of area selection is an effective tool in supporting physicians and in increasing the reliability of Ki-67 scoring in meningioma.

The virtual microscopy database-sharing digital microscope images for research and education.

PubMed

Lee, Lisa M J; Goldman, Haviva M; Hortsch, Michael

2018-02-14

Over the last 20 years, virtual microscopy has become the predominant modus of teaching the structural organization of cells, tissues, and organs, replacing the use of optical microscopes and glass slides in a traditional histology or pathology laboratory setting. Although virtual microscopy image files can easily be duplicated, creating them requires not only quality histological glass slides but also an expensive whole slide microscopic scanner and massive data storage devices. These resources are not available to all educators and researchers, especially at new institutions in developing countries. This leaves many schools without access to virtual microscopy resources. The Virtual Microscopy Database (VMD) is a new resource established to address this problem. It is a virtual image file-sharing website that allows researchers and educators easy access to a large repository of virtual histology and pathology image files. With the support from the American Association of Anatomists (Bethesda, MD) and MBF Bioscience Inc. (Williston, VT), registration and use of the VMD are currently free of charge. However, the VMD site is restricted to faculty and staff of research and educational institutions. Virtual Microscopy Database users can upload their own collection of virtual slide files, as well as view and download image files for their own non-profit educational and research purposes that have been deposited by other VMD clients. Anat Sci Educ. © 2018 American Association of Anatomists. © 2018 American Association of Anatomists.

Comparison of the Manual, Semiautomatic, and Automatic Selection and Leveling of Hot Spots in Whole Slide Images for Ki-67 Quantification in Meningiomas

PubMed Central

Swiderska, Zaneta; Korzynska, Anna; Markiewicz, Tomasz; Lorent, Malgorzata; Zak, Jakub; Wesolowska, Anna; Roszkowiak, Lukasz; Slodkowska, Janina; Grala, Bartlomiej

2015-01-01

Background. This paper presents the study concerning hot-spot selection in the assessment of whole slide images of tissue sections collected from meningioma patients. The samples were immunohistochemically stained to determine the Ki-67/MIB-1 proliferation index used for prognosis and treatment planning. Objective. The observer performance was examined by comparing results of the proposed method of automatic hot-spot selection in whole slide images, results of traditional scoring under a microscope, and results of a pathologist's manual hot-spot selection. Methods. The results of scoring the Ki-67 index using optical scoring under a microscope, software for Ki-67 index quantification based on hot spots selected by two pathologists (resp., once and three times), and the same software but on hot spots selected by proposed automatic methods were compared using Kendall's tau-b statistics. Results. Results show intra- and interobserver agreement. The agreement between Ki-67 scoring with manual and automatic hot-spot selection is high, while agreement between Ki-67 index scoring results in whole slide images and traditional microscopic examination is lower. Conclusions. The agreement observed for the three scoring methods shows that automation of area selection is an effective tool in supporting physicians and in increasing the reliability of Ki-67 scoring in meningioma. PMID:26240787

Successful fabrication of a convex platform PMMA cell-counting slide using a high-precision perpendicular dual-spindle CNC machine tool

NASA Astrophysics Data System (ADS)

Chen, Shun-Tong; Chang, Chih-Hsien

2013-12-01

This study presents a novel approach to the fabrication of a biomedical-mold for producing convex platform PMMA (poly-methyl-meth-acrylate) slides for counting cells. These slides allow for the microscopic examination of urine sediment cells. Manufacturing of such slides incorporates three important procedures: (1) the development of a tabletop high-precision dual-spindle CNC (computerized numerical control) machine tool; (2) the formation of a boron-doped polycrystalline composite diamond (BD-PCD) wheel-tool on the machine tool developed in procedure (1); and (3) the cutting of a multi-groove-biomedical-mold array using the formed diamond wheel-tool in situ on the developed machine. The machine incorporates a hybrid working platform providing wheel-tool thinning using spark erosion to cut, polish, and deburr microgrooves on NAK80 steel directly. With consideration given for the electrical conductive properties of BD-PCD, the diamond wheel-tool is thinned to a thickness of 5 µm by rotary wire electrical discharge machining. The thinned wheel-tool can grind microgrooves 10 µm wide. An embedded design, which inserts a close fitting precision core into the biomedical-mold to create step-difference (concave inward) of 50 µm in height between the core and the mold, is also proposed and realized. The perpendicular dual-spindles and precision rotary stage are features that allow for biomedical-mold machining without the necessity of uploading and repositioning materials until all tasks are completed. A PMMA biomedical-slide with a plurality of juxtaposed counting chambers is formed and its usefulness verified.

Enhanced virtual microscopy for collaborative education.

PubMed

Triola, Marc M; Holloway, William J

2011-01-26

Curricular reform efforts and a desire to use novel educational strategies that foster student collaboration are challenging the traditional microscope-based teaching of histology. Computer-based histology teaching tools and Virtual Microscopes (VM), computer-based digital slide viewers, have been shown to be effective and efficient educational strategies. We developed an open-source VM system based on the Google Maps engine to transform our histology education and introduce new teaching methods. This VM allows students and faculty to collaboratively create content, annotate slides with markers, and it is enhanced with social networking features to give the community of learners more control over the system. We currently have 1,037 slides in our VM system comprised of 39,386,941 individual JPEG files that take up 349 gigabytes of server storage space. Of those slides 682 are for general teaching and available to our students and the public; the remaining 355 slides are used for practical exams and have restricted access. The system has seen extensive use with 289,352 unique slide views to date. Students viewed an average of 56.3 slides per month during the histology course and accessed the system at all hours of the day. Of the 621 annotations added to 126 slides 26.2% were added by faculty and 73.8% by students. The use of the VM system reduced the amount of time faculty spent administering the course by 210 hours, but did not reduce the number of laboratory sessions or the number of required faculty. Laboratory sessions were reduced from three hours to two hours each due to the efficiencies in the workflow of the VM system. Our virtual microscope system has been an effective solution to the challenges facing traditional histopathology laboratories and the novel needs of our revised curriculum. The web-based system allowed us to empower learners to have greater control over their content, as well as the ability to work together in collaborative groups. The VM system saved faculty time and there was no significant difference in student performance on an identical practical exam before and after its adoption. We have made the source code of our VM freely available and encourage use of the publically available slides on our website.

Influence of sodium content on the properties of bioactive glasses for use in air abrasion.

PubMed

Farooq, Imran; Tylkowski, Maxi; Müller, Steffen; Janicki, Tomasz; Brauer, Delia S; Hill, Robert G

2013-12-01

Air abrasion is used in minimally invasive dentistry for preparing cavities, while removing no or little sound dentine or enamel, and the use of bioactive glass (rather than alumina) as an abrasive could aid in tooth remineralization. Melt-derived bioactive glasses (SiO2-P2O5-CaO-CaF2-Na2O) with low sodium content (0 to 10 mol% Na2O in exchange for CaO) for increased hardness, high phosphate content for high bioactivity and fluoride content for release of fluoride and formation of fluorapatite were produced, and particles between 38 and 80 µm in size were used for cutting soda-lime silicate glass microscope slides and human enamel. Vickers hardness increased with decreasing Na2O content, owing to a more compact silicate network in low sodium content glasses, resulting in shorter cutting times. Cutting times using bioactive glass were significantly longer than using the alumina control (29 µm) when tested on microscope slides; however, glasses showed more comparable results when cutting human enamel. The bioactive glasses formed apatite in Tris buffer within 6 h, which was significantly faster than Bioglass® 45S5 (24 h), suggesting that the hardness of the glasses makes them suitable for air abrasion application, while their high bioactivity and fluoride content make them of interest for tooth remineralization.

Spatially resolved analysis of short-range structure perturbations in a plastically bent molecular crystal

NASA Astrophysics Data System (ADS)

Panda, Manas K.; Ghosh, Soumyajit; Yasuda, Nobuhiro; Moriwaki, Taro; Mukherjee, Goutam Dev; Reddy, C. Malla; Naumov, Panče

2015-01-01

The exceptional mechanical flexibility observed with certain organic crystals defies the common perception of single crystals as brittle objects. Here, we describe the morphostructural consequences of plastic deformation in crystals of hexachlorobenzene that can be bent mechanically at multiple locations to 360° with retention of macroscopic integrity. This extraordinary plasticity proceeds by segregation of the bent section into flexible layers that slide on top of each other, thereby generating domains with slightly different lattice orientations. Microscopic, spectroscopic and diffraction analyses of the bent crystal showed that the preservation of crystal integrity when stress is applied on the (001) face requires sliding of layers by breaking and re-formation of halogen-halogen interactions. Application of stress on the (100) face, in the direction where π···π interactions dominate the packing, leads to immediate crystal disintegration. Within a broader perspective, this study highlights the yet unrecognized extraordinary malleability of molecular crystals with strongly anisotropic supramolecular interactions.

Simultaneous imaging of cellular morphology and multiple biomarkers using an acousto-optic tunable filter-based bright field microscope.

PubMed

Wachman, Elliot S; Geyer, Stanley J; Recht, Joel M; Ward, Jon; Zhang, Bill; Reed, Murray; Pannell, Chris

2014-05-01

An acousto-optic tunable filter (AOTF)-based multispectral imaging microscope system allows the combination of cellular morphology and multiple biomarker stainings on a single microscope slide. We describe advances in AOTF technology that have greatly improved spectral purity, field uniformity, and image quality. A multispectral imaging bright field microscope using these advances demonstrates pathology results that have great potential for clinical use.

The HOME tutor: a new tool for training in microscope skills.

PubMed

Gray, E; Sowter, C

1995-10-01

AxioHOME is a new concept in microscope design. It is a microscope with a visual display unit mounted in the head permitting computer generated displays to be projected on to the real microscope image when viewed down the eyepieces. This allows the annotation of the microscope image with both text and graphics. The AxioHOME system was used for the construction of complex interactive tutorials for the training and assessment of students. The basis of a tutorial is that features of interest on a microscope slide are indicated to the student who is then provided with either information or questions about those features. In turn the student can also annotate the slide with comments for later discussion with the teacher. The system therefore allows a dialogue between teacher and student. The creation of tutorials is time consuming. It takes approximately 10 min of teacher time to create 1 min of student time. However since the same tutorial can be used by numerous students this releases the teacher from repetitive training. The student response to this teaching method has been very positive. The main criticism being that insufficient teaching material was available.

Recovery of Phakopsora pachyrhizi urediniospores from Passive Spore Trap Slides and Extraction of Their DNA for Quantitative PCR

USDA-ARS?s Scientific Manuscript database

Enumeration of rust spores from passive spore traps utilizing white petrolatum-coated slides by traditional microscopic evaluation can represent a serious challenge. Many fungal spores look alike, and clear visualization on the adhesive can be obscured by particulate debris or nonuniformities within...

Anglo-American Cataloging Rules. Chapter Twelve, Revised. Audiovisual Media and Special Instructional Materials.

ERIC Educational Resources Information Center

American Library Association, Chicago, IL.

Chapter 12 of the Anglo-American Cataloging Rules has been revised to provide rules for works in the principal audiovisual media (motion pictures, filmstrips, videorecordings, slides, and transparencies) as well as instructional aids (charts, dioramas, flash cards, games, kits, microscope slides, models, and realia). The rules for main and added…

Friction law and hysteresis in granular materials

PubMed Central

Wyart, M.

2017-01-01

The macroscopic friction of particulate materials often weakens as the flow rate is increased, leading to potentially disastrous intermittent phenomena including earthquakes and landslides. We theoretically and numerically study this phenomenon in simple granular materials. We show that velocity weakening, corresponding to a nonmonotonic behavior in the friction law, μ(I), is present even if the dynamic and static microscopic friction coefficients are identical, but disappears for softer particles. We argue that this instability is induced by endogenous acoustic noise, which tends to make contacts slide, leading to faster flow and increased noise. We show that soft spots, or excitable regions in the materials, correspond to rolling contacts that are about to slide, whose density is described by a nontrivial exponent θs. We build a microscopic theory for the nonmonotonicity of μ(I), which also predicts the scaling behavior of acoustic noise, the fraction of sliding contacts χ, and the sliding velocity, in terms of θs. Surprisingly, these quantities have no limit when particles become infinitely hard, as confirmed numerically. Our analysis rationalizes previously unexplained observations and makes experimentally testable predictions. PMID:28811373

Friction law and hysteresis in granular materials

NASA Astrophysics Data System (ADS)

DeGiuli, E.; Wyart, M.

2017-08-01

The macroscopic friction of particulate materials often weakens as the flow rate is increased, leading to potentially disastrous intermittent phenomena including earthquakes and landslides. We theoretically and numerically study this phenomenon in simple granular materials. We show that velocity weakening, corresponding to a nonmonotonic behavior in the friction law, μ(I), is present even if the dynamic and static microscopic friction coefficients are identical, but disappears for softer particles. We argue that this instability is induced by endogenous acoustic noise, which tends to make contacts slide, leading to faster flow and increased noise. We show that soft spots, or excitable regions in the materials, correspond to rolling contacts that are about to slide, whose density is described by a nontrivial exponent θs. We build a microscopic theory for the nonmonotonicity of μ(I), which also predicts the scaling behavior of acoustic noise, the fraction of sliding contacts χ, and the sliding velocity, in terms of θs. Surprisingly, these quantities have no limit when particles become infinitely hard, as confirmed numerically. Our analysis rationalizes previously unexplained observations and makes experimentally testable predictions.

The virtual case: a new method to completely digitize cytological and histological slides.

PubMed

Demichelis, F; Barbareschi, M; Dalla Palma, P; Forti, S

2002-08-01

The purpose of this study was to present a new method for handling histological/cytological cases. Thanks to the introduction of information technology in pathology, including the amenities afforded by robotic microscopes and digital imaging, tissue slides can be represented and evaluated using digital techniques in order to construct virtual cases through completely automated procedures. A virtual case (VC) is composed of a collection of digital images representing a histological/cytological slide at all magnification levels together with all relevant clinical data. In the present study, we describe an automated system to manage robotic microscope and image acquisition for the proper construction of VCs. These can then be viewed on a computer by means of an interface ("user-friendly") that allows one to select the more appropriate fields and to examine them at different magnifications, rapidly going from panoramic views to high resolution and vice versa. In comparison with glass slides, VCs have several advantages arising from their digital nature and can be considered a common platform for a wide range of applications such as teleconsultation, education, research, and quality control and proficiency tests.

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.

Clinical and laboratory applications of slide-based cytometry with the LSC, SFM, and the iCYTE imaging cytometer instruments

NASA Astrophysics Data System (ADS)

Bocsi, Jozsef; Luther, Ed; Mittag, Anja; Jensen, Ingo; Sack, Ulrich; Lenz, Dominik; Trezl, Lajos; Varga, Viktor S.; Molnar, Beea; Tarnok, Attila

2004-06-01

Background: Slide based cytometry (SBC) is a technology for the rapid stoichiometric analysis of cells fixed to surfaces. Its applications are highly versatile and ranges from the clinics to high throughput drug discovery. SBC is realized in different instruments such as the Laser Scanning Cytometer (LSC) and Scanning Fluorescent Microscope (SFM) and the novel inverted microscope based iCyte image cytometer (Compucyte Corp.). Methods: Fluorochrome labeled specimens were immobilized on microscopic slides. They were placed on a conventional fluorescence microscope and analyzed by photomultiplayers or digital camera. Data comparable to flow cytometry were generated. In addition, each individual event could be visualized. Applications: The major advantage of instruments is the combination of two features: a) the minimal sample volume needed, and b) the connection of fluorescence data and morphological information. Rare cells were detected, frequency of apoptosis by myricetin formaldehyde and H2O2 mixtures was determined;. Conclusion: LSC, SFM and the novel iCyte have a wide spectrum of applicability in SBC and can be introduced as a standard technology for multiple settings. In addition, the iCyte and SFM instrument is suited for high throughput screening by automation and may be in future adapted to telepathology due to their high quality images. (This study was supported by the IZKF-Leipzig, Germany and T 034245 OTKA, Hungary)

Microscopic endometrial perivascular epithelioid cell nodules: a case report with the earliest presentation of a uterine perivascular epithelioid cell tumor

PubMed Central

2012-01-01

Abstract Perivascular epithelioid cell (PEC) tumors (PEComas) are a family of related mesenchymal tumors composed of PECs which co-express melanocytic and smooth muscle markers. Although their distinctive histologic, immunohistochemical, ultrastructural, and genetic features have been clearly demonstrated, their histogenesis and normal counterpart remain largely unknown. Precursor lesions of PEComas have rarely been reported. We herein describe a tuberous sclerosis patient with microscopic PEC nodules in the endometrium of adenomyosis, pelvic endometriosis, an ovarian endometriotic cyst, and the endometrium of the uterine cavity. The nodules showed a mixture of spindle-shaped and epithelioid cells concentrically arranged around small arteries. The cells exhibited uniform nuclei, light eosinophilic cytoplasm, and immunoreactivity with HMB-45 and CD10. Some nodules revealed continuity with a PEComa in the myometrium. These findings support microscopic endometrial PEC nodules possibly being precursor lesions of uterine PEComas. The wide distribution of the nodules in the pelvis may be related to the multicentricity of PEComas in tuberous sclerosis patients. Owing to the immunoreactivity with CD10, microscopic endometrial PEC nodules may be misinterpreted as endothelial stromal cells unless melanocytic markers are stained. To the best of our knowledge, this is a case with the earliest manifestation of PEC lesions occurring in the endometrium. Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9658280017862643 PMID:22937790

Microscopic endometrial perivascular epithelioid cell nodules: a case report with the earliest presentation of a uterine perivascular epithelioid cell tumor.

PubMed

Fang, Chia-Lang; Lin, Yun-Ho; Chen, Wei-Yu

2012-09-03

Perivascular epithelioid cell (PEC) tumors (PEComas) are a family of related mesenchymal tumors composed of PECs which co-express melanocytic and smooth muscle markers. Although their distinctive histologic, immunohistochemical, ultrastructural, and genetic features have been clearly demonstrated, their histogenesis and normal counterpart remain largely unknown. Precursor lesions of PEComas have rarely been reported. We herein describe a tuberous sclerosis patient with microscopic PEC nodules in the endometrium of adenomyosis, pelvic endometriosis, an ovarian endometriotic cyst, and the endometrium of the uterine cavity. The nodules showed a mixture of spindle-shaped and epithelioid cells concentrically arranged around small arteries. The cells exhibited uniform nuclei, light eosinophilic cytoplasm, and immunoreactivity with HMB-45 and CD10. Some nodules revealed continuity with a PEComa in the myometrium. These findings support microscopic endometrial PEC nodules possibly being precursor lesions of uterine PEComas. The wide distribution of the nodules in the pelvis may be related to the multicentricity of PEComas in tuberous sclerosis patients. Owing to the immunoreactivity with CD10, microscopic endometrial PEC nodules may be misinterpreted as endothelial stromal cells unless melanocytic markers are stained. To the best of our knowledge, this is a case with the earliest manifestation of PEC lesions occurring in the endometrium. Virtual slides: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9658280017862643.

Microscope Cells Containing Multiple Micromachined Wells

NASA Technical Reports Server (NTRS)

Turner, Walter; Skupinski, Robert

2003-01-01

Tech Briefs, May 2003 19 Manufacturing Microscope Cells Containing Multiple Micromachined Wells The cost per cell has been reduced substantially. John H. Glenn Research Center, Cleveland, Ohio An improved design for multiple-well microscope cells and an associated improved method of fabricating them have been devised. [As used here, "well" denotes a cavity that has a volume of about 1 or 2 L and that is used to hold a sample for examination under a microscope. As used here, "cell" denotes a laminate, based on a standard 1- by 3-in. (2.54- by 7.62-cm) microscope slide, that comprises (1) the slide as the lower layer, (2) an intermediate layer that contains holes that serve as the wells, and (3) a top layer that either consists of, or is similar to, a standard microscope-slide cover slip.] The improved design and method of fabrication make it possible to increase (relative to a prior design and method of fabrication) the number of wells per cell while reducing the fabrication loss and reducing the cost per cell to about one-tenth of the prior value. In the prior design and method, the slide, well, and cover-slip layers were made from silicate glass. The fabrication of each cell was a labor-intensive process that included precise cutting and grinding of the glass components, fusing of the glass components, and then more grinding and polishing to obtain desired dimensions. Cells of the prior design were expensive and fragile, the rate of loss in fabrication was high, and the nature of the glass made it difficult to increase the number of cells per well. Efforts to execute alternative prior designs in plastic have not yielded satisfactory results because, for typical applications, plastics are not sufficiently thermally or chemically stable, not sufficiently optically clear, and/or not hard enough to resist scratching. The figure depicts a cell of the present improved type. The slide and cover-slip layers are made of a low-thermal-expansion glass (Pyrex(TradeMark) or equivalent) and the intermediate (well layer) is made of SiO2 - a combination of materials that results in a laminate stronger than one made from layers of silicate glass. Before the layers are assembled into the laminate, the SiO2 layer is micromachined to form the wells plus shallow grooves that, when subsequently covered with the cover slip, become capillary channels that are used to fill the wells with samples. The micromachining is accomplished by use of the same patterning and etching techniques used to fabricate microelectromechanical systems (MEMS).

Using the Blue Gourami in Ethological and Embryological Studies.

ERIC Educational Resources Information Center

Thompson, Theresa; Pollak, Edward I.

1981-01-01

Lists advantages in the use of the blue gourami in laboratory experiments on reproduction and embryogenesis. Materials and procedures for maintaining and spawning blue gouramis are provided. Also includes details on microscopic examination of developing embryos and histological techniques for microscope slide preparation. (CS)

Fabrication and characterization of novel microsphere-embedded optical devices for enhancing microscopy resolution

NASA Astrophysics Data System (ADS)

Darafsheh, Arash

2018-02-01

Microsphere-assisted imaging can be incorporated onto conventional light microscopes allowing wide-field and flourescence imaging with enhanced resolution. We demonstrated that imaging of specimens containing subdiffraction-limited features is achievable through high-index microspheres embedded in a transparent thin film placed over the specimen. We fabricated novel microsphere-embedded microscope slides composed of barium titanate glass microspheres (with diameter 10-100 μm and refractive index 1.9-2.2) embedded in a transparent polydimethylsiloxane (PDMS) elastomer layer with controllable thickness. We characterized the imaging performance of such microsphere-embedded devices in white-light microscopies, by measuring the imaging resolution, field-of-view, and magnification as a function of microsphere size. Our results inform on the design of novel optical devices, such as microsphere-embedded microscope slides for imaging applications.

Screening small-molecule compound microarrays for protein ligands without fluorescence labeling with a high-throughput scanning microscope.

PubMed

Fei, Yiyan; Landry, James P; Sun, Yungshin; Zhu, Xiangdong; Wang, Xiaobing; Luo, Juntao; Wu, Chun-Yi; Lam, Kit S

2010-01-01

We describe a high-throughput scanning optical microscope for detecting small-molecule compound microarrays on functionalized glass slides. It is based on measurements of oblique-incidence reflectivity difference and employs a combination of a y-scan galvometer mirror and an x-scan translation stage with an effective field of view of 2 cm x 4 cm. Such a field of view can accommodate a printed small-molecule compound microarray with as many as 10,000 to 20,000 targets. The scanning microscope is capable of measuring kinetics as well as endpoints of protein-ligand reactions simultaneously. We present the experimental results on solution-phase protein reactions with small-molecule compound microarrays synthesized from one-bead, one-compound combinatorial chemistry and immobilized on a streptavidin-functionalized glass slide.

Screening small-molecule compound microarrays for protein ligands without fluorescence labeling with a high-throughput scanning microscope

PubMed Central

Fei, Yiyan; Landry, James P.; Sun, Yungshin; Zhu, Xiangdong; Wang, Xiaobing; Luo, Juntao; Wu, Chun-Yi; Lam, Kit S.

2010-01-01

We describe a high-throughput scanning optical microscope for detecting small-molecule compound microarrays on functionalized glass slides. It is based on measurements of oblique-incidence reflectivity difference and employs a combination of a y-scan galvometer mirror and an x-scan translation stage with an effective field of view of 2 cm×4 cm. Such a field of view can accommodate a printed small-molecule compound microarray with as many as 10,000 to 20,000 targets. The scanning microscope is capable of measuring kinetics as well as endpoints of protein-ligand reactions simultaneously. We present the experimental results on solution-phase protein reactions with small-molecule compound microarrays synthesized from one-bead, one-compound combinatorial chemistry and immobilized on a streptavidin-functionalized glass slide. PMID:20210464

Comparison study of five different display modalities for whole slide images in surgical pathology and cytopathology in Europe

NASA Astrophysics Data System (ADS)

D'Haene, Nicky; Maris, Calliope; Rorive, Sandrine; Moles Lopez, Xavier; Rostang, Johan; Marchessoux, Cédric; Pantanowitz, Liron; Parwani, Anil V.; Salmon, Isabelle

2013-03-01

User experience with viewing images in pathology is crucial for accurate interpretation and diagnosis. With digital pathology, images are being read on a display system, and this poses new types of questions: such as what is the difference in terms of pixelation, refresh lag or obscured features compared to an optical microscope. Is there a resultant change in user performance in terms of speed of slide review, perception of adequacy and quality or in diagnostic confidence? A prior psychophysical study was carried out comparing various display modalities on whole slide imaging (WSI) in pathology at the University of Pittsburgh Medical Center (UPMC) in the USA. This prior study compared professional and non-professional grade display modalities and highlighted the importance of using a medical grade display to view pathological digital images. This study was duplicated in Europe at the Department of Pathology in Erasme Hospital (Université Libre de Bruxelles (ULB)) in an attempt to corroborate these findings. Digital WSI with corresponding glass slides of 58 cases including surgical pathology and cytopathology slides of varying difficulty were employed. Similar non-professional and professional grade display modalities were compared to an optical microscope (Olympus BX51). Displays ranged from a laptop (DELL Latitude D620), to a consumer grade display (DELL E248WFPb), to two professional grade monitors (Eizo CG245W and Barco MDCC-6130). Three pathologists were selected from the Department of Pathology in Erasme Hospital (ULB) in Belgium to view and interpret the pathological images on these different displays. The results show that non-professional grade displays (laptop and consumer) have inferior user experience compared to professional grade monitors and the optical microscope.

Influence of Ultrasonic Surface Rolling on Microstructure and Wear Behavior of Selective Laser Melted Ti-6Al-4V Alloy

PubMed Central

Wang, Zhen; Xiao, Zhiyu; Huang, Chuanshou; Wen, Liping; Zhang, Weiwen

2017-01-01

The present article studied the effect of ultrasonic surface rolling process (USRP) on the microstructure and wear behavior of a selective laser melted Ti-6Al-4V alloy. Surface characteristics were investigated using optical microscope, nano-indentation, scanning electron microscope, transmission electron microscope and laser scanning confocal microscope. Results indicated that the thickness of pore-free surfaces increased to 100~200 μm with the increasing ultrasonic surface rolling numbers. Severe work hardening occurred in the densified layer, resulting in the formation of refined grains, dislocation walls and deformation twins. After 1000 N 6 passes, about 15.5% and 14.1% increment in surficial Nano-hardness and Vickers-hardness was obtained, respectively. The hardness decreased gradually from the top surface to the substrate. Wear tests revealed that the friction coefficient declined from 0.74 (polished surface) to 0.64 (USRP treated surface) and the wear volume reduced from 0.205 mm−3 to 0.195 mm−3. The difference in wear volume between USRP treated and polished samples increased with sliding time. The enhanced wear resistance was concluded to be associated with the improvement of hardness and shear resistance and also the inhibition of delamination initiation. PMID:29048344

Fiber Longitudinal Measurements for Predicting White Speck Contents of Dyed Cotton Fabrics

USDA-ARS?s Scientific Manuscript database

Fiber Image Analysis System (FIAS) was developed to provide an automatic method for measuring cotton maturity from fiber snippets or cross-sections . An uncombed cotton bundle is chopped and sprayed on a microscopic slide. The snippets are imaged sequentially on an microscope and measured with custo...

Towards better digital pathology workflows: programming libraries for high-speed sharpness assessment of Whole Slide Images.

PubMed

Ameisen, David; Deroulers, Christophe; Perrier, Valérie; Bouhidel, Fatiha; Battistella, Maxime; Legrès, Luc; Janin, Anne; Bertheau, Philippe; Yunès, Jean-Baptiste

2014-01-01

Since microscopic slides can now be automatically digitized and integrated in the clinical workflow, quality assessment of Whole Slide Images (WSI) has become a crucial issue. We present a no-reference quality assessment method that has been thoroughly tested since 2010 and is under implementation in multiple sites, both public university-hospitals and private entities. It is part of the FlexMIm R&D project which aims to improve the global workflow of digital pathology. For these uses, we have developed two programming libraries, in Java and Python, which can be integrated in various types of WSI acquisition systems, viewers and image analysis tools. Development and testing have been carried out on a MacBook Pro i7 and on a bi-Xeon 2.7GHz server. Libraries implementing the blur assessment method have been developed in Java, Python, PHP5 and MySQL5. For web applications, JavaScript, Ajax, JSON and Sockets were also used, as well as the Google Maps API. Aperio SVS files were converted into the Google Maps format using VIPS and Openslide libraries. We designed the Java library as a Service Provider Interface (SPI), extendable by third parties. Analysis is computed in real-time (3 billion pixels per minute). Tests were made on 5000 single images, 200 NDPI WSI, 100 Aperio SVS WSI converted to the Google Maps format. Applications based on our method and libraries can be used upstream, as calibration and quality control tool for the WSI acquisition systems, or as tools to reacquire tiles while the WSI is being scanned. They can also be used downstream to reacquire the complete slides that are below the quality threshold for surgical pathology analysis. WSI may also be displayed in a smarter way by sending and displaying the regions of highest quality before other regions. Such quality assessment scores could be integrated as WSI's metadata shared in clinical, research or teaching contexts, for a more efficient medical informatics workflow.

AccessScope project: Accessible light microscope for users with upper limb mobility or visual impairments.

PubMed

Mansoor, Awais; Ahmed, Wamiq M; Samarapungavan, Ala; Cirillo, John; Schwarte, David; Robinson, J Paul; Duerstock, Bradley S

2010-01-01

A web-based application was developed to remotely view slide specimens and control all functions of a research-level light microscopy workstation, called AccessScope. Students and scientists with upper limb mobility and visual impairments are often unable to use a light microscope by themselves and must depend on others in its operation. Users with upper limb mobility impairments and low vision were recruited to assist in the design process of the AccessScope personal computer (PC) user interface. Participants with these disabilities were evaluated in their ability to use AccessScope to perform microscopical tasks. AccessScope usage was compared with inspecting prescanned slide images by grading participants' identification and understanding of histological features and knowledge of microscope operation. With AccessScope subjects were able to independently perform common light microscopy functions through an Internet browser by employing different PC pointing devices or accessibility software according to individual abilities. Subjects answered more histology and microscope usage questions correctly after first participating in an AccessScope test session. AccessScope allowed users with upper limb or visual impairments to successfully perform light microscopy without assistance. This unprecedented capability is crucial for students and scientists with disabilities to perform laboratory coursework or microscope-based research and pursue science, technology, engineering, and mathematics fields.

Rapid detection of food pathogens using RNA aptamers-immobilized slide.

PubMed

Maeng, Jin-Soo; Kim, Namsoo; Kim, Chong-Tai; Han, Seung Ryul; Lee, Young Ju; Lee, Seong-Wook; Lee, Myung-Hyun; Cho, Yong-Jin

2012-07-01

The purpose of this study was to develop a simple and rapid detection system for foodborne bacteria, which consisted of an optical microscope and its slide chip with artificial antibodies, or RNA aptamers. From an RNA pool, three each RNA aptamers were built by the method of SELEX (systematic evolution of ligands by exponential enrichment) for components of cell wall, LPS (lipopolysaccharide) from E. coli O157:H7, teichoic acid from Staphylococcus aureus and a cell membrane protein of OmpC from Salmonella typhimurium, respectively. These aptamers were hybridized with thiol-conjugated 16 dT-linker molecules in order to be immobilized on silver surface which was, in advance, fabricated on glass slide, using a spin-coating method. To confirm that each aptamers retained its specific binding activities to their antigenic live bacteria, microscopic view of bound cells immobilized on silver film were observed. Furthermore, we observed the fluorescence-emitting bacteria-aptamer complex immobilized on silver film after adding RNA aptamers hybridized with fluorophore, FAM-conjugated 16 dT-linker molecules. As a result, the RNA aptamers-immobilized slide system developed in this study was a useful new tool to rapidly monitor individual food pathogens.

Ultraviolet Light Enhances the Bovine Serum Albumin Fixation for Acid Fast Bacilli Stain

PubMed Central

Lai, Pei-Yin; Lee, Shih-Yi; Chou, Yu-Ching; Fu, Yung-Chieh; Wu, Chen-Cheng; Chiueh, Tzong-Shi

2014-01-01

The use of a liquid culture system such as MGIT broth has greatly improved the sensitivity of isolating mycobacteria in clinical laboratories. Microscopic visualization of acid fast bacilli (AFB) in the culture positive MGIT broth remains the first routine step for rapidly indicating the presence of mycobacteria. We modified an ultraviolet (UV) light fixation process to increase AFB cells adherence to the slide. The retained haze proportion of a 1-cm circle marked area on the smear slide was quantified after the staining procedure indicating the adherence degree of AFB cells. More AFB cells were preserved on the slide after exposure to UV light of either germicidal lamp or UV crosslinker in a time-dependent manner. We demonstrated both the bovine serum albumin (BSA) in MGIT media and UV light exposure were required for enhancing fixation of AFB cells. While applying to AFB stains for 302 AFB positive MGIT broths in clinics, more AFB cells were retained and observed on smear slides prepared by the modified fixation procedure rather than by the conventional method. The modified fixation procedure was thus recommended for improving the sensitivity of microscopic diagnosis of AFB cells in culture positive MGIT broth. PMID:24586725

How about a Log for Lunch?

ERIC Educational Resources Information Center

Brooks, Susan; Bonner, Sheveeta C.

2008-01-01

Many students do not have the manual dexterity to keep up with a fast-moving paramecium on a microscope slide. The lowly termite, however, provides an easily observable microscopic endo-ecosystem in an environment not usually considered by middle school teachers. In the activity described here, students examine the gut fauna of a termite in what…

Tunable deformation modes shape contractility in active biopolymer networks

NASA Astrophysics Data System (ADS)

Stam, Samantha; Banerjee, Shiladitya; Weirich, Kim; Freedman, Simon; Dinner, Aaron; Gardel, Margaret

Biological polymer-based materials remodel under active, molecular motor-driven forces to perform diverse physiological roles, such as force transmission and spatial self-organization. Critical to understanding these biomaterials is elucidating the role of microscopic polymer deformations, such as stretching, bending, buckling, and relative sliding, on material remodeling. Here, we report that the shape of motor-driven deformations can be used to identify microscopic deformation modes and determine how they propagate to longer length scales. In cross-linked actin networks with sufficiently low densities of the motor protein myosin II, microscopic network deformations are predominantly uniaxial, or dominated by sliding. However, longer-wavelength modes are mostly biaxial, or dominated by bending and buckling, indicating that deformations with uniaxial shapes do not propagate across length scales significantly larger than that of individual polymers. As the density of myosin II is increased, biaxial modes dominate on all length scales we examine due to buildup of sufficient stress to produce smaller-wavelength buckling. In contrast, when we construct networks from unipolar, rigid actin bundles, we observe uniaxial, sliding-based contractions on 1 to 100 μm length scales. Our results demonstrate the biopolymer mechanics can be used to tune deformation modes which, in turn, control shape changes in active materials.

Physical and Microstructure Properties of MgAl2C2 Matrix Composite Coating on Titanium

NASA Astrophysics Data System (ADS)

Li, Peng

2014-12-01

This work is based on the dry sliding wear of the MgAl2C2-TiB2-FeSi composite coating deposited on a pure Ti using a laser cladding technique. Scanning electron microscope images indicate that the nanocrystals and amorphous phases are produced in such coating. X-ray diffraction result indicated that such coating mainly consists of MgAl2C2, Ti-B, Ti-Si, Fe-Al, Ti3SiC2, TiC and amorphous phases. The high resolution transmission electron microscope image indicated that the TiB nanorods were produced in the coating, which were surrounded by other fine precipitates, favoring the formation of a fine microstructure. With increase of the laser power from 0.85 kW to 1.00 kW, the micro-hardness decreased from 1350 1450 HV0.2 to 1200 1300 HV0.2. The wear volume loss of the laser clad coating was 1/7 of pure Ti.

Surface functionalisation with viscosity-sensitive BODIPY molecular rotor

NASA Astrophysics Data System (ADS)

Vyšniauskas, Aurimas; Lopez-Duarte, Ismael; Thompson, Alex J.; Bull, James A.; Kuimova, Marina K.

2018-07-01

Surface functionalisation with viscosity sensitive dyes termed ‘molecular rotors’ can potentially open up new opportunities in sensing, for example for non-invasive biological viscosity imaging, in studying the effect of shear stress on lipid membranes and in cells, and in imaging contacts between surfaces upon applied pressure. We have functionalised microscope slides with BODIPY-based molecular rotor capable of viscosity sensing via its fluorescence lifetime. We have optimised functionalisation conditions and prepared the slides with the BODIPY rotor attached directly to the surface of glass slides and through polymer linkers of 5 kDa and 40 kDa in mass. The slides were characterised for their sensitivity to viscosity, and used to measure viscosity of supported lipid bilayers during photooxidation, and of giant unilamellar vesicles lying on the surface of the slide. We conclude that our functionalised slides show promise for a variety of viscosity sensing applications.

Whole slide imaging of unstained tissue using lensfree microscopy

NASA Astrophysics Data System (ADS)

Morel, Sophie Nhu An; Hervé, Lionel; Bordy, Thomas; Cioni, Olivier; Delon, Antoine; Fromentin, Catherine; Dinten, Jean-Marc; Allier, Cédric

2016-04-01

Pathologist examination of tissue slides provides insightful information about a patient's disease. Traditional analysis of tissue slides is performed under a binocular microscope, which requires staining of the sample and delays the examination. We present a simple cost-effective lensfree imaging method to record 2-4μm resolution wide-field (10 mm2 to 6 cm2) images of unstained tissue slides. The sample processing time is reduced as there is no need for staining. A wide field of view (10 mm2) lensfree hologram is recorded in a single shot and the image is reconstructed in 2s providing a very fast acquisition chain. The acquisition is multispectral, i.e. multiple holograms are recorded simultaneously at three different wavelengths, and a dedicated holographic reconstruction algorithm is used to retrieve both amplitude and phase. Whole tissue slides imaging is obtained by recording 130 holograms with X-Y translation stages and by computing the mosaic of a 25 x 25 mm2 reconstructed image. The reconstructed phase provides a phase-contrast-like image of the unstained specimen, revealing structures of healthy and diseased tissue. Slides from various organs can be reconstructed, e.g. lung, colon, ganglion, etc. To our knowledge, our method is the first technique that enables fast wide-field lensfree imaging of such unlabeled dense samples. This technique is much cheaper and compact than a conventional phase contrast microscope and could be made portable. In sum, we present a new methodology that could quickly provide useful information when a rapid diagnosis is needed, such as tumor margin identification on frozen section biopsies during surgery.

Optical redox imaging of fixed unstained tissue slides to identify biomarkers for breast cancer diagnosis/prognosis: feasibility study

NASA Astrophysics Data System (ADS)

Xu, He N.; Tchou, Julia; Li, Yusheng; Feng, Min; Zhang, Paul; Quinn, William J.; Baur, Joseph A.; Li, Lin Z.

2018-02-01

We previously showed that optical redox imaging (ORI) of snap-frozen breast biopsies by the Chance redox scanner readily discriminates cancer from normal tissue. Moreover, indices of redox heterogeneity differentiate among tumor xenografts with different metastatic potential. These observations suggest that ORI of fluorescence of NADH and oxidized flavoproteins (Fp) may provide diagnostic/prognostic value for clinical applications. In this work, we investigate whether ORI of formalin-fixed-paraffin-embedded (FFPE) unstained clinical tissue slides of breast tumors is feasible and comparable to ORI of snap-frozen tumors. If ORI of FFPE is validated, it will enhance the versatility of ORI as a novel diagnostic/prognostic assay as FFPE samples are readily available. ORI of fixed tissue slides was performed using a fluorescence microscope equipped with a precision automated stage and appropriate optical filters. We developed a vignette correction algorithm to remove the tiling effect of stitched-images. The preliminary data from imaging fixed slides of breast tumor xenografts showed intratumor redox heterogeneity patterns similar to that of the frozen tissues imaged by the Chance redox scanner. From ORI of human breast tissue slides we identified certain redox differences among normal, ductal carcinoma in situ, and invasive carcinoma. We found paraformaldehyde fixation causes no change in NADH signals but enhances Fp signals of fresh muscle fibers. We also investigated the stability of the fluorescence microscope and reproducibility of tissue slide fluorescence signals. We plan to validate the diagnostic/prognostic value of ORI using clinically annotated breast cancer sample set from patients with long-term follow-up data.

The effect of ion plated silver and sliding friction on tensile stress-induced cracking in aluminum oxide

NASA Technical Reports Server (NTRS)

Sliney, Harold E.; Spalvins, Talivaldis

1991-01-01

A Hertzian analysis of the effect of sliding friction on contact stresses in alumina is used to predict the critical load for crack generation. The results for uncoated alumina and alumina coated with ion plated silver are compared. Friction coefficient inputs to the analysis are determined experimentally with a scratch test instrument employing an 0.2 mm radius diamond stylus. A series of scratches were made at constant load increments on coated and uncoated flat alumina surfaces. Critical loads for cracking are detected by microscopic examination of cross sections of scratches made at various loads and friction coefficients. Acoustic emission (AE) and friction trends were also evaluated as experimental techniques for determining critical loads for cracking. Analytical predictions correlate well with micrographic evidence and with the lowest load at which AE is detected in multiple scratch tests. Friction/load trends are not good indicators of early crack formation. Lubrication with silver films reduced friction and thereby increased the critical load for crack initiation in agreement with analytical predictions.

The effect of ion-plated silver and sliding friction on tensile stress-induced cracking in aluminum oxide

NASA Technical Reports Server (NTRS)

Sliney, Harold E.; Spalvins, Talivaldis

1993-01-01

A Hertzian analysis of the effect of sliding friction on contact stresses in alumina is used to predict the critical load for crack generation. The results for uncoated alumina and alumina coated with ion plated silver are compared. Friction coefficient inputs to the analysis are determined experimentally with a scratch test instrument employing an 0.2 mm radius diamond stylus. A series of scratches were made at constant load increments on coated and uncoated flat alumina surfaces. Critical loads for cracking are detected by microscopic examination of cross sections of scratches made at various loads and friction coefficients. Acoustic emission (AE) and friction trends were also evaluated as experimental techniques for determining critical loads for cracking. Analytical predictions correlate well with micrographic evidence and with the lowest load at which AE is detected in multiple scratch tests. Friction/load trends are not good indicators of early crack formation. Lubrication with silver films reduced friction and thereby increased the critical load for crack initiation in agreement with analytical predictions.

42 CFR 37.203 - Autopsy specifications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... the ventricular surface and shall not include trabeculations or pericardial fat. The right ventricle... diaphragm; (vii) From each type of suspected pneumoconiotic lesion, representative microscopic slides...

42 CFR 37.203 - Autopsy specifications.

Code of Federal Regulations, 2011 CFR

2011-10-01

... diaphragm; (vii) From each type of suspected pneumoconiotic lesion, representative microscopic slides...-impregnated blocks of tissue shall be submitted. (b) Needle biopsy techniques shall not be used. ...

Structural and phase transformations in Hadfield steel upon frictional loading in liquid nitrogen

NASA Astrophysics Data System (ADS)

Korshunov, L. G.; Sagaradze, V. V.; Chernenko, N. L.

2016-08-01

Structural transformations that occur in 110G13 steel (Hadfield) upon sliding friction in liquid nitrogen (-196°C) have been investigated by metallographic, electron-microscopic, and X-ray diffraction methods. The frictional action was performed through the reciprocating sliding of a cylindrical indenter of quenched 110G13 steel over a plate of the studied steel. A like friction pair was immersed into a bath with liquid nitrogen. It has been shown that the Hadfield steel quenched from 1100°C under the given temperature conditions of frictional loading retains the austenitic structure completely. The frictional action forms in a surface layer up to 10 μm thick the nanocrystalline structure with austenite grains 10-50 nm in size and a hardness 6 GPa. Upon subsequent low-temperature friction, the tempering of steel at 400°C (3 h) and at 600°C (5 min and 5 h) brings about the formation of a large amount (tens of vol %) of ɛ (hcp) martensite in steel. The formation of this phase under friction is supposedly a consequence of the reduction in the stacking fault energy of Hadfield steel, which is achieved due to the combined action of the following factors: low-temperature cooling, a decrease in the carbon content in the austenite upon tempering, and the presence of high compressive stresses in the friction-contact zone.

Evidence of a rolling motion of a microparticle on a silicon wafer in a liquid environment

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

Schiwek, Simon; Stark, Robert W., E-mail: stark@csi.tu-darmstadt.de, E-mail: dietz@csi.tu-darmstadt.de; Dietz, Christian, E-mail: stark@csi.tu-darmstadt.de, E-mail: dietz@csi.tu-darmstadt.de

2016-05-21

The interaction of micro- and nanometer-sized particles with surfaces plays a crucial role when small-scale structures are built in a bottom-up approach or structured surfaces are cleaned in the semiconductor industry. For a reliable quantification of the interaction between individual particles and a specific surface, however, the motion type of the particle must be known. We developed an approach to unambiguously distinguish between sliding and rolling particles. To this end, fluorescent particles were partially bleached in a confocal laser scanning microscope to tailor an optical inhomogeneity, which allowed for the identification of the characteristic motion pattern. For the manipulation, themore » water flow generated by a fast moving cantilever-tip of an atomic force microscope enabled the contactless pushing of the particle. We thus experimentally evidenced a rolling motion of a micrometer-sized particle directly with a fluorescence microscope. A similar approach could help to discriminate between rolling and sliding particles in liquid flows of microfluidic systems.« less

Implementation of large-scale routine diagnostics using whole slide imaging in Sweden: Digital pathology experiences 2006-2013

PubMed Central

Thorstenson, Sten; Molin, Jesper; Lundström, Claes

2014-01-01

Recent technological advances have improved the whole slide imaging (WSI) scanner quality and reduced the cost of storage, thereby enabling the deployment of digital pathology for routine diagnostics. In this paper we present the experiences from two Swedish sites having deployed routine large-scale WSI for primary review. At Kalmar County Hospital, the digitization process started in 2006 to reduce the time spent at the microscope in order to improve the ergonomics. Since 2008, more than 500,000 glass slides have been scanned in the routine operations of Kalmar and the neighboring Linköping University Hospital. All glass slides are digitally scanned yet they are also physically delivered to the consulting pathologist who can choose to review the slides on screen, in the microscope, or both. The digital operations include regular remote case reporting by a few hospital pathologists, as well as around 150 cases per week where primary review is outsourced to a private clinic. To investigate how the pathologists choose to use the digital slides, a web-based questionnaire was designed and sent out to the pathologists in Kalmar and Linköping. The responses showed that almost all pathologists think that ergonomics have improved and that image quality was sufficient for most histopathologic diagnostic work. 38 ± 28% of the cases were diagnosed digitally, but the survey also revealed that the pathologists commonly switch back and forth between digital and conventional microscopy within the same case. The fact that two full-scale digital systems have been implemented and that a large portion of the primary reporting is voluntarily performed digitally shows that large-scale digitization is possible today. PMID:24843825

Development of a high-throughput Candida albicans biofilm chip.

PubMed

Srinivasan, Anand; Uppuluri, Priya; Lopez-Ribot, Jose; Ramasubramanian, Anand K

2011-04-22

We have developed a high-density microarray platform consisting of nano-biofilms of Candida albicans. A robotic microarrayer was used to print yeast cells of C. albicans encapsulated in a collagen matrix at a volume as low as 50 nL onto surface-modified microscope slides. Upon incubation, the cells grow into fully formed "nano-biofilms". The morphological and architectural complexity of these biofilms were evaluated by scanning electron and confocal scanning laser microscopy. The extent of biofilm formation was determined using a microarray scanner from changes in fluorescence intensities due to FUN 1 metabolic processing. This staining technique was also adapted for antifungal susceptibility testing, which demonstrated that, similar to regular biofilms, cells within the on-chip biofilms displayed elevated levels of resistance against antifungal agents (fluconazole and amphotericin B). Thus, results from structural analyses and antifungal susceptibility testing indicated that despite miniaturization, these biofilms display the typical phenotypic properties associated with the biofilm mode of growth. In its final format, the C. albicans biofilm chip (CaBChip) is composed of 768 equivalent and spatially distinct nano-biofilms on a single slide; multiple chips can be printed and processed simultaneously. Compared to current methods for the formation of microbial biofilms, namely the 96-well microtiter plate model, this fungal biofilm chip has advantages in terms of miniaturization and automation, which combine to cut reagent use and analysis time, minimize labor intensive steps, and dramatically reduce assay costs. Such a chip should accelerate the antifungal drug discovery process by enabling rapid, convenient and inexpensive screening of hundreds-to-thousands of compounds simultaneously.

Superlubric sliding of graphene nanoflakes on graphene.

PubMed

Feng, Xiaofeng; Kwon, Sangku; Park, Jeong Young; Salmeron, Miquel

2013-02-26

The lubricating properties of graphite and graphene have been intensely studied by sliding a frictional force microscope tip against them to understand the origin of the observed low friction. In contrast, the relative motion of free graphene layers remains poorly understood. Here we report a study of the sliding behavior of graphene nanoflakes (GNFs) on a graphene surface. Using scanning tunneling microscopy, we found that the GNFs show facile translational and rotational motions between commensurate initial and final states at temperatures as low as 5 K. The motion is initiated by a tip-induced transition of the flakes from a commensurate to an incommensurate registry with the underlying graphene layer (the superlubric state), followed by rapid sliding until another commensurate position is reached. Counterintuitively, the average sliding distance of the flakes is larger at 5 K than at 77 K, indicating that thermal fluctuations are likely to trigger their transitions from superlubric back to commensurate ground states.

Plastic deformation and wear process at a surface during unlubricated sliding

NASA Technical Reports Server (NTRS)

Yamamoto, T.; Buckley, D. H.

1982-01-01

The plastic deformation and wear of a 304 stainless steel surface sliding against an aluminum oxide rider with a spherical surface (the radius of curvature: 1.3 cm) were observed by using scanning electron and optical microscopes. Experiments were conducted in a vacuum of one million Pa and in an environment of fifty thousandth Pa of chlorine gas at 25 C. The load was 500 grams and the sliding velocity was 0.5 centimeter per second. The deformed surface layer which accumulates and develops successively is left behind the rider, and step shaped proturbances are developed even after single pass sliding under both environmental conditions. A fully developed surface layer is gradually torn off leaving a characteristic pattern. The mechanism for tearing away of the surface layer from the contact area and sliding track contour is explained assuming the simplified process of material removal based on the adhesion theory for the wear of materials.

Precise and economic FIB/SEM for CLEM: with 2 nm voxels through mitosis.

PubMed

Luckner, Manja; Wanner, Gerhard

2018-05-23

A portfolio is presented documenting economic, high-resolution correlative focused ion beam scanning electron microscopy (FIB/SEM) in routine, comprising: (i) the use of custom-labeled slides and coverslips, (ii) embedding of cells in thin, or ultra-thin resin layers for correlative light and electron microscopy (CLEM) and (iii) the claim to reach the highest resolution possible with FIB/SEM in xyz. Regions of interest (ROIs) defined in light microscope (LM), can be relocated quickly and precisely in SEM. As proof of principle, HeLa cells were investigated in 3D context at all stages of the cell cycle, documenting ultrastructural changes during mitosis: nuclear envelope breakdown and reassembly, Golgi degradation and reconstitution and the formation of the midzone and midbody.

Working at the microscope: analysis of the activities involved in diagnostic pathology.

PubMed

Randell, Rebecca; Ruddle, Roy A; Quirke, Phil; Thomas, Rhys G; Treanor, Darren

2012-02-01

To study the current work practice of histopathologists to inform the design of digital microscopy systems. Four gastrointestinal histopathologists were video-recorded as they undertook their routine work. Analysis of the video data shows a range of activities beyond viewing slides involved in reporting a case. There is much overlapping of activities, supported by the 'eyes free' nature of the pathologists' interaction with the microscope. The order and timing of activities varies according to consultant. In order to support the work of pathologists adequately, digital microscopy systems need to provide support for a range of activities beyond viewing slides. Digital microscopy systems should support multitasking, while also providing flexibility so that pathologists can adapt their use of the technology to their own working patterns. © 2011 Blackwell Publishing Ltd.

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.

Horizontal sliding of kilometre-scale hot spring area during the 2016 Kumamoto earthquake

PubMed Central

Tsuji, Takeshi; Ishibashi, Jun’ichiro; Ishitsuka, Kazuya; Kamata, Ryuichi

2017-01-01

We report horizontal sliding of the kilometre-scale geologic block under the Aso hot springs (Uchinomaki area) caused by vibrations from the 2016 Kumamoto earthquake (Mw 7.0). Direct borehole observations demonstrate the sliding along the horizontal geological formation at ~50 m depth, which is where the shallowest hydrothermal reservoir developed. Owing to >1 m northwest movement of the geologic block, as shown by differential interferometric synthetic aperture radar (DInSAR), extensional open fissures were generated at the southeastern edge of the horizontal sliding block, and compressional deformation and spontaneous fluid emission from wells were observed at the northwestern edge of the block. The temporal and spatial variation of the hot spring supply during the earthquake can be explained by the horizontal sliding and borehole failures. Because there was no strain accumulation around the hot spring area prior to the earthquake and gravitational instability could be ignored, the horizontal sliding along the low-frictional formation was likely caused by seismic forces from the remote earthquake. The insights derived from our field-scale observations may assist further research into geologic block sliding in horizontal geological formations. PMID:28218298

Towards better digital pathology workflows: programming libraries for high-speed sharpness assessment of Whole Slide Images

PubMed Central

2014-01-01

Background Since microscopic slides can now be automatically digitized and integrated in the clinical workflow, quality assessment of Whole Slide Images (WSI) has become a crucial issue. We present a no-reference quality assessment method that has been thoroughly tested since 2010 and is under implementation in multiple sites, both public university-hospitals and private entities. It is part of the FlexMIm R&D project which aims to improve the global workflow of digital pathology. For these uses, we have developed two programming libraries, in Java and Python, which can be integrated in various types of WSI acquisition systems, viewers and image analysis tools. Methods Development and testing have been carried out on a MacBook Pro i7 and on a bi-Xeon 2.7GHz server. Libraries implementing the blur assessment method have been developed in Java, Python, PHP5 and MySQL5. For web applications, JavaScript, Ajax, JSON and Sockets were also used, as well as the Google Maps API. Aperio SVS files were converted into the Google Maps format using VIPS and Openslide libraries. Results We designed the Java library as a Service Provider Interface (SPI), extendable by third parties. Analysis is computed in real-time (3 billion pixels per minute). Tests were made on 5000 single images, 200 NDPI WSI, 100 Aperio SVS WSI converted to the Google Maps format. Conclusions Applications based on our method and libraries can be used upstream, as calibration and quality control tool for the WSI acquisition systems, or as tools to reacquire tiles while the WSI is being scanned. They can also be used downstream to reacquire the complete slides that are below the quality threshold for surgical pathology analysis. WSI may also be displayed in a smarter way by sending and displaying the regions of highest quality before other regions. Such quality assessment scores could be integrated as WSI's metadata shared in clinical, research or teaching contexts, for a more efficient medical informatics workflow. PMID:25565494

Synthesis and statistical modelling of dry sliding wear of Al 8011/6 vol.% AlB2 in situ composite

NASA Astrophysics Data System (ADS)

Kumar, Narendra; Singh, Sandeep Kumar; Gautam, Gaurav; Padap, Aditya Kumar; Mohan, Anita; Mohan, Sunil

2017-10-01

The present study has used response surface methodology (RSM) and central composite design (CCD) for modelling, using wear parameters to predict the wear performance of an Al 8011/6.0 vol.% AlB2 composite. The effect of applied load and sliding velocity was studied at five levels for a fixed sliding distance. To understand wear behaviour, sliding wear tests were planned according to CCD and performed on a pin-on-disc apparatus at ambient temperature. An analysis of variance (ANOVA) was conducted to show the relative significance of the parameters. A second-order regression model was developed to predict the wear loss and to establish the relationships between wear parameters. Response surface and contour plots were drawn to analyse the wear results. Worn surfaces were examined under scanning electron microscope (SEM), and energy dispersive spectroscopy (EDS) was used to interpret the operative wear mechanisms. Validation tests results show good agreement between experimental and predicted data. As an initial step of this study, AlB2 particles were reinforced in Al 8011 alloy by an in situ technique to synthesise an Al 8011/6.0 vol.% AlB2 composite. During synthesis an in situ reaction takes place between molten alloy and inorganic salt KBF4 at 850 °C, which leads to the formation of AlB2 particles. The composite was analysed by x-ray diffractometer (XRD) to detect the phases present, while optical and scanning electron microscopy (OM & SEM) were carried out to ascertain morphology and particle distribution. Hardness was evaluated by a Vickers hardness testing machine.

Dating Fossil Pollen: A Simulation.

ERIC Educational Resources Information Center

Sheridan, Philip

1992-01-01

Describes a hands-on simulation in which students determine the age of "fossil" pollen samples based on the pollen types present when examined microscopically. Provides instructions for the preparation of pollen slides. (MDH)

A modular, open-source, slide-scanning microscope for diagnostic applications in resource-constrained settings

PubMed Central

Lu, Qiang; Liu, Guanghui; Xiao, Chuanli; Hu, Chuanzhen; Zhang, Shiwu; Xu, Ronald X.; Chu, Kaiqin; Xu, Qianming

2018-01-01

In this paper we report the development of a cost-effective, modular, open source, and fully automated slide-scanning microscope, composed entirely of easily available off-the-shelf parts, and capable of bright field and fluorescence modes. The automated X-Y stage is composed of two low-cost micrometer stages coupled to stepper motors operated in open-loop mode. The microscope is composed of a low-cost CMOS sensor and low-cost board lenses placed in a 4f configuration. The system has approximately 1 micron resolution, limited by the f/# of available board lenses. The microscope is compact, measuring just 25×25×30 cm, and has an absolute positioning accuracy of ±1 μm in the X and Y directions. A Z-stage enables autofocusing and imaging over large fields of view even on non-planar samples, and custom software enables automatic determination of sample boundaries and image mosaicking. We demonstrate the utility of our device through imaging of fluorescent- and transmission-dye stained blood and fecal smears containing human and animal parasites, as well as several prepared tissue samples. These results demonstrate image quality comparable to high-end commercial microscopes at a cost of less than US$400 for a bright-field system, with an extra US$100 needed for the fluorescence module. PMID:29543835

Distance reporting in digital pathology: A study on 950 cases

PubMed Central

Vodovnik, Aleksandar

2015-01-01

Background: Increased workload, case complexity, financial constraints, and staffing shortages justify wider implementations of digital pathology. One of its main advantages is distance reporting. Aim: A feasibility study was conducted at our institution in order to achieve comprehensive pathology services available by distance. Methods: One senior pathologist reported 950 cases (3,650 slides) by distance during 19 weeks. Slides were scanned by ScanScope AT Turbo (Aperio) and digital images accessed through SymPathy (Tieto) on a 14” laptop. Mobile phone, mobile broadband, broadband over Wi-Fi and broadband were used for internet connections along with a virtual private network technology (VPN). Lync (Microsoft) was tested for one case consultation and resident's teaching session. Larger displays were accessed when available. Effects of ergonomics and working flexibility on the user experience were observed. Details on network speed, frequency of technical issues, data usage, scanning, and turnaround, were collected and evaluated. Turnaround was compared to in-office microscopic reporting, measured from the registration to sign off. Results: Network speeds varied 1–80 Mbps (median download speed 8–65 Mbps). 20 Mbps were satisfactory for the instant upload of digital images. VPN, image viewer, and laptop failed on two occasions each. An estimated data usage per digital image was 10 MB (1–50 MB). Two cases (15 slides) were deferred to microscopic slides (0.21/0.41%) due to scanty material and suboptimal slide quality. Additional nine cases (15 slides) needed to be rescanned for various reasons (0.95/0.41%). Average turnaround was shorter, and the percentage of cases reported up to 3 days higher (3.13 days/72.25%) comparing with in-office microscopic reporting (3.90 days/40.56%). Larger displays improved the most user experience at magnifications over ×20. Conclusions: Existing IT solutions at our institution allow efficient and reliable distance reporting for the core pathology services in histology and cytology. Stable network speeds, fully integrated laboratory information management system, technical reliability, working flexibility, larger displays, and shorter turnaround contributed to the overall satisfaction with distance reporting. A further expansion of our pathology services available by distance, diagnostic and educational, rely on gaining experience in digital reporting and marginal IT investment. Adjustments to the organization of pathology services may follow to fully benefit from the implementation of digital pathology. PMID:25969793

Distance reporting in digital pathology: A study on 950 cases.

PubMed

Vodovnik, Aleksandar

2015-01-01

Increased workload, case complexity, financial constraints, and staffing shortages justify wider implementations of digital pathology. One of its main advantages is distance reporting. A feasibility study was conducted at our institution in order to achieve comprehensive pathology services available by distance. One senior pathologist reported 950 cases (3,650 slides) by distance during 19 weeks. Slides were scanned by ScanScope AT Turbo (Aperio) and digital images accessed through SymPathy (Tieto) on a 14" laptop. Mobile phone, mobile broadband, broadband over Wi-Fi and broadband were used for internet connections along with a virtual private network technology (VPN). Lync (Microsoft) was tested for one case consultation and resident's teaching session. Larger displays were accessed when available. Effects of ergonomics and working flexibility on the user experience were observed. Details on network speed, frequency of technical issues, data usage, scanning, and turnaround, were collected and evaluated. Turnaround was compared to in-office microscopic reporting, measured from the registration to sign off. Network speeds varied 1-80 Mbps (median download speed 8-65 Mbps). 20 Mbps were satisfactory for the instant upload of digital images. VPN, image viewer, and laptop failed on two occasions each. An estimated data usage per digital image was 10 MB (1-50 MB). Two cases (15 slides) were deferred to microscopic slides (0.21/0.41%) due to scanty material and suboptimal slide quality. Additional nine cases (15 slides) needed to be rescanned for various reasons (0.95/0.41%). Average turnaround was shorter, and the percentage of cases reported up to 3 days higher (3.13 days/72.25%) comparing with in-office microscopic reporting (3.90 days/40.56%). Larger displays improved the most user experience at magnifications over ×20. Existing IT solutions at our institution allow efficient and reliable distance reporting for the core pathology services in histology and cytology. Stable network speeds, fully integrated laboratory information management system, technical reliability, working flexibility, larger displays, and shorter turnaround contributed to the overall satisfaction with distance reporting. A further expansion of our pathology services available by distance, diagnostic and educational, rely on gaining experience in digital reporting and marginal IT investment. Adjustments to the organization of pathology services may follow to fully benefit from the implementation of digital pathology.

Adhesive Wear Performance of CFRP Multilayered Polyester Composites Under Dry/wet Contact Conditions

NASA Astrophysics Data System (ADS)

Danaelan, D.; Yousif, B. F.

The tribo-performance of a new engineering composite material based on coconut fibers was investigated. In this work, coconut fibers reinforced polyester (CFRP) composites were developed. The tribo-experiments were conducted by using pin-on-disc machine under dry and wet sliding contact condition against smooth stainless steel counterface. Worn surfaces were observed using optical microscope. Friction coefficient and specific wear rate were presented as a function of sliding distance (0-0.6 km) at different sliding velocities (0.1-0.28 m/s). The effect of applied load and sliding velocity was evaluated. The results showed that all test parameters have significant influence on friction and wear characteristics of the composites. Moreover, friction coefficient increased as the normal load and speed increased, the values were about 0.7-0.9 under dry contact condition. Meanwhile, under wet contact condition, there was a great reduction in the friction coefficient, i.e. the values were about 0.1-0.2. Furthermore, the specific wear rates were found to be around 2-4 (10-3) mm3/Nm under dry contact condition and highly reduced under wet condition. In other words, the presence of water as cleaner and polisher assisted to enhance the adhesive wear performance of CFRP by about 10%. The images from optical microscope showed evidence of adhesive wear mode with transition to abrasive wear mode at higher sliding velocities due to third body abrasion. On the other hand, optical images for wet condition showed less adhesive wear and smooth surfaces.

Techniques for Generating Instructional Slides. Final Report.

ERIC Educational Resources Information Center

Smith, Edgar A.; And Others

Common in briefing presentations and in individualized instruction is the use of slides that present materials prepared on a typewriter (questions, instructions, outlines). To increase the efficiency and effectiveness of producing these kind of slides a procedure was developed to facilitate: (1) formatting copy to be used for slides; (2) using…

44 CFR Appendix 1 to Part 323 - List of Essential Survival Items

Code of Federal Regulations, 2014 CFR

2014-10-01

.... Laboratory glassware. Microscope and slides. Water purification apparatus. Group B None. ii. food Group A 1...) in drums, cans, ampules. Iodine tablets. Liquid chlorine, including containers. Chlorine compounds...

Cyto-histopathological and outcome features of the prepuce squamous cell carcinoma of a mixed breed dog

PubMed Central

2014-01-01

Abstract Background Squamous cell carcinomas (SCCs) are uncommon, high-grade tumors, predominantly composed of round cells in the prepuce. The aim of this study is to better define the clinicopathologic features of this neoplasm. Case report We conducted cyto-histopathologic analysis on the manifestations of the prepuce SCC by H & E staining in a terrier mix dog. Grossly, tumor was large, multiple erythematous patch, and ulcerated masses frequently affecting the prepuce and deeply invading to distal prepuce out from the ventro-lateral of penis and the tumor covered by a necrotic discharge. Cytological evaluation of fine-needle aspirates from the cutaneous mass from the prepuce comprised of round nuclei, coarse chromatin pattern, distinct nucleoli and nuclear pleomorphism. Furthermore, the neoplastic cells were pleomorphic, round to caudate in shape, exhibiting prominent anisokaryosis and anisocytosis with rare mitotic features. Microscopically, the lesions were predominantly composed of atypical round cells disposed in interlacing fascicles. Frequent findings include keratin formation, horn pearls, mitoses and cellular atypia. The cells showed distinct borders, ranged from polygonal to round or elongate and had moderate amounts of eosinophilic cytoplasm. Conclusion The histopathologic features coupled with the cytopathology findings led to a diagnosis of squamous cell carcinoma. To the authors’ knowledge, this is the first time that multiple erythematous plaques have undergone malignant transformation in a terrier mix dog. Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5748771971272873 PMID:24903567

High resolution computational on-chip imaging of biological samples using sparsity constraint (Conference Presentation)

NASA Astrophysics Data System (ADS)

Rivenson, Yair; Wu, Chris; Wang, Hongda; Zhang, Yibo; Ozcan, Aydogan

2017-03-01

Microscopic imaging of biological samples such as pathology slides is one of the standard diagnostic methods for screening various diseases, including cancer. These biological samples are usually imaged using traditional optical microscopy tools; however, the high cost, bulkiness and limited imaging throughput of traditional microscopes partially restrict their deployment in resource-limited settings. In order to mitigate this, we previously demonstrated a cost-effective and compact lens-less on-chip microscopy platform with a wide field-of-view of >20-30 mm^2. The lens-less microscopy platform has shown its effectiveness for imaging of highly connected biological samples, such as pathology slides of various tissue samples and smears, among others. This computational holographic microscope requires a set of super-resolved holograms acquired at multiple sample-to-sensor distances, which are used as input to an iterative phase recovery algorithm and holographic reconstruction process, yielding high-resolution images of the samples in phase and amplitude channels. Here we demonstrate that in order to reconstruct clinically relevant images with high resolution and image contrast, we require less than 50% of the previously reported nominal number of holograms acquired at different sample-to-sensor distances. This is achieved by incorporating a loose sparsity constraint as part of the iterative holographic object reconstruction. We demonstrate the success of this sparsity-based computational lens-less microscopy platform by imaging pathology slides of breast cancer tissue and Papanicolaou (Pap) smears.

Digital pathology for the primary diagnosis of breast histopathological specimens: an innovative validation and concordance study on digital pathology validation and training.

PubMed

Williams, Bethany Jill; Hanby, Andrew; Millican-Slater, Rebecca; Nijhawan, Anju; Verghese, Eldo; Treanor, Darren

2018-03-01

To train and individually validate a group of breast pathologists in specialty-specific digital primary diagnosis by using a novel protocol endorsed by the Royal College of Pathologists' new guideline for digital pathology. The protocol allows early exposure to live digital reporting, in a risk-mitigated environment, and focuses on patient safety and professional development. Three specialty breast pathologists completed training in the use of a digital microscopy system, and were exposed to a training set of 20 challenging cases, designed to help them identify personal digital diagnostic pitfalls. Following this, the three pathologists viewed a total of 694 live, entire breast cases. All primary diagnoses were made on digital slides, with immediate glass slide review and reconciliation before final case sign-out. There was complete clinical concordance between the glass and digital impression of the case in 98.8% of cases. Only 1.2% of cases had a clinically significant difference in diagnosis/prognosis on glass and digital slide reads. All pathologists elected to continue using the digital microscope as the standard for breast histopathology specimens, with deferral to glass for a limited number of clinical/histological scenarios as a safety net. Individual training and validation for digital primary diagnosis allows pathologists to develop competence and confidence in their digital diagnostic skills, and aids safe and responsible transition from the light microscope to the digital microscope. © 2017 John Wiley & Sons Ltd.

Transition to Virtual Microscopy in Medical Undergraduate Pathology Education: First Experience of Turkey in Dokuz Eylül University Hospital.

PubMed

Sağol, Özgül; Yörükoğlu, Kutsal; Lebe, Banu; Durak, Merih Güray; Ulukuş, Çağnur; Tuna, Burçin; Musal, Berna; Canda, Tülay; Özer, Erdener

2015-01-01

Pathology education includes an important visual part supporting a wide range of theoretical knowledge. However, the use of traditional microscopes in pathology education has declined over the last decade and there is a lack of interest for microscopy. Virtual microscopy, which was first described in 1985 and has experienced a revolution since 2000, is an alternative technique to conventional microscopy, in which microscopic slides are scanned to form digital images and stored in the web. The aim of this study was to evaluate the use of virtual microscopy in practical pathology sessions and its effects on our students and undergraduate education at our faculty. Second and third year medical students who were used to conventional microscopes were included in the study. The practical sessions were carried out via virtual slides and the effect of the new technique was investigated by a scale at the end of each session. Academic staff from the pathology department joined sessions to promote discussion and respond to questions. Student ratings were analysed statistically. The evaluation of the ratings showed that the students were easily adapted to the use of virtual microscopy. They found it user-friendly and thought that the opportunity of viewing slides at home was advantageous. Collaboration between students and interactive discussions was also improved with this technique. It was concluded that the use of virtual microscopy could contribute to the pathology education of our students.

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

Bureau of Mines War Gas Investigations (WGI) Monographs (Old Series)

DTIC Science & Technology

2015-01-01

Yellow Smoke Cartridges 119 4. V.B. Discharger Cup 124 5. 25mm Very cartridge – yellow smoke 125 6. 35 mm Yellow and Red Smoke...Reports General 15 Measurement 20 Corona method 20 Microscope slide method 21 Ultra microscopic method 23 Different methods...James and Finnegan 87 13. Use of Silent Discharge in Inducing Chemical Reaction: Weiser and Gross 96 CS 2: Reports 14-25, Part II

Plastic deformation and wear process at a surface during unlubricated sliding

NASA Technical Reports Server (NTRS)

Yamamoto, T.; Buckley, D. H.

1983-01-01

The plastic deformation and wear of a 304 stainless steel surface sliding against an aluminum oxide rider with a spherical surface (the radius of curvature: 1.3 cm) were observed by using scanning electron and optical microscopes. Experiments were conducted in a vacuum of one million Pa and in an environment of fifty thousandth Pa of chlorine gas at 25 C. The load was 500 grams and the sliding velocity was 0.5 centimeter per second. The deformed surface layer which accumulates and develops successively is left behind the rider, and step shaped proturbances are developed even after single pass sliding under both environmental conditions. A fully developed surface layer is gradually torn off leaving a characteristic pattern. The mechanism for tearing away of the surface layer from the contact area and sliding track contour is explained assuming the simplified process of material removal based on the adhesion theory for the wear of materials. Previously announced in STAR as N82-32735

Light-sheet microscopy for slide-free non-destructive pathology of large clinical specimens

PubMed Central

Glaser, Adam K.; Reder, Nicholas P.; Chen, Ye; McCarty, Erin F.; Yin, Chengbo; Wei, Linpeng; Wang, Yu; True, Lawrence D.; Liu, Jonathan T.C.

2017-01-01

For the 1.7 million patients per year in the U.S. who receive a new cancer diagnosis, treatment decisions are largely made after a histopathology exam. Unfortunately, the gold standard of slide-based microscopic pathology suffers from high inter-observer variability and limited prognostic value due to sampling limitations and the inability to visualize tissue structures and molecular targets in their native 3D context. Here, we show that an open-top light-sheet microscope optimized for non-destructive slide-free pathology of clinical specimens enables the rapid imaging of intact tissues at high resolution over large 2D and 3D fields of view, with the same level of detail as traditional pathology. We demonstrate the utility of this technology for various applications: wide-area surface microscopy to triage surgical specimens (with ~200 μm surface irregularities), rapid intraoperative assessment of tumour-margin surfaces (12.5 sec/cm2), and volumetric assessment of optically cleared core–needle biopsies (1 mm in diameter, 2 cm in length). Light-sheet microscopy can be a versatile tool for both rapid surface microscopy and deep volumetric microscopy of human specimens. PMID:29750130

Extraneous tissue in surgical pathology: a College of American Pathologists Q-Probes study of 275 laboratories.

PubMed

Gephardt, G N; Zarbo, R J

1996-11-01

To develop a multi-institutional reference database of extraneous tissue (contaminants) in surgical pathology. In 1994, participants in the College of American Pathologists Q-Probes quality improvement program performed prospective and retrospective evaluations of extraneous tissue found in surgical pathology microscopic sections for a period of 4 weeks or until 1000 slides were reviewed in each participating laboratory. Two hundred seventy-five surgical pathology laboratories institutions, predominantly from North America. Extraneous tissue contamination rate for slides in prospective and retrospective reviews; staffing and practice procedures; location of extraneous tissue on slides; type of extraneous tissue (normal, abnormal, nonneoplastic, neoplasm, microorganisms, etc); class of extraneous tissue (slide or block contaminants); source of extraneous tissue (different or same case); origin of extraneous tissue (pathology laboratory, physician's office or operating room); and degree of diagnostic difficulty caused by extraneous tissue. Three hundred twenty-one thousand seven hundred fifty-seven slides were reviewed in the prospective study and 57083 slides in the retrospective study. There was an overall extraneous tissue rate of 0.6% of slides (2074/321757) in the prospective study and 2.9% of slides (1653/57083) in the retrospective study. Of those slides with extraneous tissue, the extraneous tissue was located near diagnostic tissue sections in 59.5% of the slides reviewed prospectively and in 25.3% of slides reviewed retrospectively; deeper sections were performed to evaluate extraneous tissue in 12.2% of prospective cases and in 3.1% of retrospective cases. Of the laboratories, 98% had written guidelines for changing solution in tissue processors, and 64.9% had guidelines for maintaining water baths free of extraneous tissue. A total of 98.9% used lens paper, filter bags, or sponges for processing fragmented and small specimens. Written protocols for documentation of extraneous tissue in surgical pathology reports were established in 6.1% of laboratories, for removal of extraneous tissue from blocks in 5.7%, and for removal of extraneous tissue from microscopic slides in 4.7%. In 24% of laboratories no comment or record was kept to document extraneous tissue. Extraneous tissue consisted of neoplasm in 12.7% of the prospectively reviewed slides and in 6.0% of the retrospectively reviewed slides. For the prospective study, 59.4% of extraneous tissue was classified as slide contaminants, and 28.4% was found to be contaminants within the paraffin block; for the retrospective study, 72.9% was classified as slide contaminants and 15.9% as block contaminants. For the prospective study, 63.2% of extraneous tissue was presumed to be from a different case, and in the retrospective study, 48.5% was presumed to be from a different case. Over 90% of extraneous tissue was thought to originate from the pathology laboratory. The degree of diagnostic difficulty caused by extraneous tissue was judged to be severe in 0.4% of slides in the prospective study and 0.1% of slides in the retrospective study. In the prospective study, it could not be determined whether the tissue in the diagnostic sections was extraneous in 0.6% of slides, and in the retrospective study, it could not be determined whether tissue in the diagnostic sections was extraneous in 0.1%. This study has documented the frequency, type, origin, source, and diagnostic difficulty of extraneous tissue and presents benchmarks of extraneous tissue experienced in the general practice of surgical pathology.

A Duo of Potassium-Responsive Histidine Kinases Govern the Multicellular Destiny of Bacillus subtilis.

PubMed

Grau, Roberto R; de Oña, Paula; Kunert, Maritta; Leñini, Cecilia; Gallegos-Monterrosa, Ramses; Mhatre, Eisha; Vileta, Darío; Donato, Verónica; Hölscher, Theresa; Boland, Wilhelm; Kuipers, Oscar P; Kovács, Ákos T

2015-07-07

Multicellular biofilm formation and surface motility are bacterial behaviors considered mutually exclusive. However, the basic decision to move over or stay attached to a surface is poorly understood. Here, we discover that in Bacillus subtilis, the key root biofilm-controlling transcription factor Spo0A~Pi (phosphorylated Spo0A) governs the flagellum-independent mechanism of social sliding motility. A Spo0A-deficient strain was totally unable to slide and colonize plant roots, evidencing the important role that sliding might play in natural settings. Microarray experiments plus subsequent genetic characterization showed that the machineries of sliding and biofilm formation share the same main components (i.e., surfactin, the hydrophobin BslA, exopolysaccharide, and de novo-formed fatty acids). Sliding proficiency was transduced by the Spo0A-phosphorelay histidine kinases KinB and KinC. We discovered that potassium, a previously known inhibitor of KinC-dependent biofilm formation, is the specific sliding-activating signal through a thus-far-unnoticed cytosolic domain of KinB, which resembles the selectivity filter sequence of potassium channels. The differential expression of the Spo0A~Pi reporter abrB gene and the different levels of the constitutively active form of Spo0A, Sad67, in Δspo0A cells grown in optimized media that simultaneously stimulate motile and sessile behaviors uncover the spatiotemporal response of KinB and KinC to potassium and the gradual increase in Spo0A~Pi that orchestrates the sequential activation of sliding, followed by sessile biofilm formation and finally sporulation in the same population. Overall, these results provide insights into how multicellular behaviors formerly believed to be antagonistic are coordinately activated in benefit of the bacterium and its interaction with the host. Alternation between motile and sessile behaviors is central to bacterial adaptation, survival, and colonization. However, how is the collective decision to move over or stay attached to a surface controlled? Here, we use the model plant-beneficial bacterium Bacillus subtilis to answer this question. Remarkably, we discover that sessile biofilm formation and social sliding motility share the same structural components and the Spo0A regulatory network via sensor kinases, KinB and KinC. Potassium, an inhibitor of KinC-dependent biofilm formation, triggers sliding via a potassium-perceiving cytosolic domain of KinB that resembles the selectivity filter of potassium channels. The spatiotemporal response of these kinases to variable potassium levels and the gradual increase in Spo0A~Pi levels that orchestrates the activation of sliding before biofilm formation shed light on how multicellular behaviors formerly believed to be antagonistic work together to benefit the population fitness. Copyright © 2015 Grau et al.

On decentralized adaptive full-order sliding mode control of multiple UAVs.

PubMed

Xiang, Xianbo; Liu, Chao; Su, Housheng; Zhang, Qin

2017-11-01

In this study, a novel decentralized adaptive full-order sliding mode control framework is proposed for the robust synchronized formation motion of multiple unmanned aerial vehicles (UAVs) subject to system uncertainty. First, a full-order sliding mode surface in a decentralized manner is designed to incorporate both the individual position tracking error and the synchronized formation error while the UAV group is engaged in building a certain desired geometric pattern in three dimensional space. Second, a decentralized virtual plant controller is constructed which allows the embedded low-pass filter to attain the chattering free property of the sliding mode controller. In addition, robust adaptive technique is integrated in the decentralized chattering free sliding control design in order to handle unknown bounded uncertainties, without requirements for assuming a priori knowledge of bounds on the system uncertainties as stated in conventional chattering free control methods. Subsequently, system robustness as well as stability of the decentralized full-order sliding mode control of multiple UAVs is synthesized. Numerical simulation results illustrate the effectiveness of the proposed control framework to achieve robust 3D formation flight of the multi-UAV system. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

The Easy Way to Create Computer Slide Shows.

ERIC Educational Resources Information Center

Anderson, Mary Alice

1995-01-01

Discusses techniques for creating computer slide shows. Topics include memory; format; color use; HyperCard and CD-ROM; font styles and sizes; graphs and graphics; the slide show option; special effects; and tips for effective presentation. (Author/AEF)

USING DIRICHLET TESSELLATION TO HELP ESTIMATE MICROBIAL BIOMASS CONCENTRATIONS

EPA Science Inventory

Dirichlet tessellation was applied to estimate microbial concentrations from microscope well slides. The use of microscopy/Dirichlet tessellation to quantify biomass was illustrated with two species of morphologically distinct cyanobacteria, and validated empirically by compariso...

Some wear studies on aircraft brake systems

NASA Technical Reports Server (NTRS)

Ho, T. L.

1975-01-01

An initial investigation of worn surfaces in friction pads and steel rotors used in current aircraft brakes was carried out using electron microprobe and X-ray diffraction analysis. It consists of the topographical study and the analysis of chemical element distribution. Based upon this initial examination, two approaches, microscopic and macroscopic have been conducted to interpret and formulate the wear mechanism of the aircraft brake materials. Microscopically, the wear particles were examined. The initiation and growth of surface cracks and the oxidation were emphasized in this investigation. Macroscopically, it has been found that, for the current copper based brake material sliding against 17-22 AS steel in a caliper brake, the surface temperature raised due to frictional heat is nonlinearly proportional to the load applied and slide time with speed at 1750 rpm. The wear of brake materials is then proportional to this temperature and is also a function of the melting temperature for copper.

DIY: "Do Imaging Yourself" - Conventional microscopes as powerful tools for in vivo investigation.

PubMed

Antunes, Maísa Mota; Carvalho, Érika de; Menezes, Gustavo Batista

2018-01-01

Intravital imaging has been increasingly employed in cell biology studies and it is becoming one of the most powerful tools for in vivo investigation. Although some protocols can be extremely complex, most intravital imaging procedures can be performed using basic surgery and animal maintenance techniques. More importantly, regular confocal microscopes - the same that are used for imaging immunofluorescence slides - can also acquire high quality intravital images and movies after minor adaptations. Here we propose minimal adaptations in stock microscopes that allow major improvements in different fields of scientific investigation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Time Dependent Frictional Changes in Ice due to Contact Area Changes

NASA Astrophysics Data System (ADS)

Sevostianov, V.; Lipovsky, B. P.; Rubinstein, S.; Dillavou, S.

2017-12-01

Sliding processes along the ice-bed interface of Earth's great ice sheets are the largest contributor to our uncertainty in future sea level rise. Laboratory experiments that have probed sliding processes have ubiquitously shown that ice-rock interfaces strengthen while in stationary contact (Schulson and Fortt, 2013; Zoet et al., 2013; McCarthy et al., 2017). This so-called frictional ageing effect may have profound consequences for ice sheet dynamics because it introduces the possibility of basal strength hysteresis. Furthermore this effect is quite strong in ice-rock interfaces (more than an order of magnitude more pronounced than in rock-rock sliding) and can double in frictional strength in a matter of minutes, much faster than most frictional aging (Dieterich, 1972; Baumberger and Caroli, 2006). Despite this importance, the underling physics of frictional ageing of ice remain poorly understood. Here we conduct laboratory experiments to image the microscopic points of contact along an ice-glass interface. We optically measure changes in the real area of contact over time using measurements of this reflected optical light intensity. We show that contact area increases with time of stationary contact. This result suggests that thermally enhanced creep of microscopic icy contacts is responsible for the much larger frictional ageing observed in ice-rock versus rock-rock interfaces. Furthermore, this supports a more physically detailed description of the thermal dependence of basal sliding than that used in the current generation of large scale ice sheet models.

XPS analysis of 440C steel surfaces lubricated with perfluoropolyethers under sliding conditions in high vacuum

NASA Technical Reports Server (NTRS)

Herrera-Fierro, Pilar; Masuko, Masabumi; Jones, William R., Jr.; Pepper, Stephen V.

1994-01-01

This work presents the results of the X-Ray Photoelectron Spectroscopy (XPS) analysis of AISI 440C ball surfaces lubricated with perfluoropolyether (PFPE) oils after friction experiments under sliding conditions at high load in air and vacuum environments. The PFPE lubricants tested were Demnum S100, Fomblin Z-25, and Krytox 143AB. It was found that all the PFPE lubricants were degraded by sliding contact causing the formation of inorganic fluorides on the metallic surfaces and a layer of organic decomposition products. KRYTOX 143AB was the least reactive of the three lubricants tested. It was also found that metal fluoride formed at off-scar areas. This suggests the formation of reactive species, such as COF2 or R(sub f)COF, during sliding experiments, which can diffuse through the lubricant film and react with the metallic surfaces away from the contact region. Comparison of reference specimens before sliding with those that had undergone the sliding tests showed that the amount of non-degraded PFPE remaining on the surface of the balls after the sliding experiments was greater than that of the balls without sliding.

An Introduction to Photomicrography.

ERIC Educational Resources Information Center

Judson, Peter

1979-01-01

Described are various methods for producing black and white photographs of microscope slides using single lens reflex, fixed lens, and plate cameras. Procedures for illumination, film processing, mounting, and projection are also discussed. A table of comparative film speeds is included. (CS)

Biology Notes.

ERIC Educational Resources Information Center

School Science Review, 1983

1983-01-01

Describes laboratory procedures, demonstrations, and classroom activities/materials, including chi-square tests on a microcomputer, an integrated biology game, microscope slides of leaf stomata, culturing soil nematodes, technique for watering locust egg-laying tubes, hazards of biological chemicals (such as benzene, benzidene, calchicine,…

Utilizing Whole Slide Images for Pathology Peer Review and Working Groups.

PubMed

Malarkey, David E; Willson, Gabrielle A; Willson, Cynthia J; Adams, E Terence; Olson, Greg R; Witt, William M; Elmore, Susan A; Hardisty, Jerry F; Boyle, Michael C; Crabbs, Torrie A; Miller, Rodney A

2015-12-01

This article describes the results of comparisons of digitally scanned whole slide images (WSIs) and glass microscope slides for diagnosis of tissues under peer review by the National Toxicology Program. Findings in this article were developed as a result of the data collected from 6 pathology working groups (PWGs), 1 pathology peer review, and survey comments from over 25 participating pathologists. For each PWG, 6-14 pathologists examined 10-143 tissues per study from 6- and 9-month perinatal studies and 2-year carcinogenicity studies. Overall it was found that evaluation of WSIs is generally equivalent to using glass slides. Concordance of PWG consensus diagnoses based upon review of WSIs versus glass slides ranged from 74% to 100% (median 86%). The intra- and interobserver diagnostic variation did not appear to influence the conclusions of any study. Based upon user opinions collected from surveys, WSIs may be less optimal than glass slides for evaluation of subtle lesions, large complex lesions, small lesions in a large section of tissue, and foci of altered hepatocytes. These results indicate that, although there may be some limitations, the use of WSIs can effectively accomplish the objectives of a conventional glass slide review and definitely serves as a useful adjunct to the conduct of PWGs. © 2015 by The Author(s).

Point-of-care mobile digital microscopy and deep learning for the detection of soil-transmitted helminths and Schistosoma haematobium.

PubMed

Holmström, Oscar; Linder, Nina; Ngasala, Billy; Mårtensson, Andreas; Linder, Ewert; Lundin, Mikael; Moilanen, Hannu; Suutala, Antti; Diwan, Vinod; Lundin, Johan

2017-06-01

Microscopy remains the gold standard in the diagnosis of neglected tropical diseases. As resource limited, rural areas often lack laboratory equipment and trained personnel, new diagnostic techniques are needed. Low-cost, point-of-care imaging devices show potential in the diagnosis of these diseases. Novel, digital image analysis algorithms can be utilized to automate sample analysis. Evaluation of the imaging performance of a miniature digital microscopy scanner for the diagnosis of soil-transmitted helminths and Schistosoma haematobium, and training of a deep learning-based image analysis algorithm for automated detection of soil-transmitted helminths in the captured images. A total of 13 iodine-stained stool samples containing Ascaris lumbricoides, Trichuris trichiura and hookworm eggs and 4 urine samples containing Schistosoma haematobium were digitized using a reference whole slide-scanner and the mobile microscopy scanner. Parasites in the images were identified by visual examination and by analysis with a deep learning-based image analysis algorithm in the stool samples. Results were compared between the digital and visual analysis of the images showing helminth eggs. Parasite identification by visual analysis of digital slides captured with the mobile microscope was feasible for all analyzed parasites. Although the spatial resolution of the reference slide-scanner is higher, the resolution of the mobile microscope is sufficient for reliable identification and classification of all parasites studied. Digital image analysis of stool sample images captured with the mobile microscope showed high sensitivity for detection of all helminths studied (range of sensitivity = 83.3-100%) in the test set (n = 217) of manually labeled helminth eggs. In this proof-of-concept study, the imaging performance of a mobile, digital microscope was sufficient for visual detection of soil-transmitted helminths and Schistosoma haematobium. Furthermore, we show that deep learning-based image analysis can be utilized for the automated detection and classification of helminths in the captured images.

Point-of-care mobile digital microscopy and deep learning for the detection of soil-transmitted helminths and Schistosoma haematobium

PubMed Central

Holmström, Oscar; Linder, Nina; Ngasala, Billy; Mårtensson, Andreas; Linder, Ewert; Lundin, Mikael; Moilanen, Hannu; Suutala, Antti; Diwan, Vinod; Lundin, Johan

2017-01-01

ABSTRACT Background: Microscopy remains the gold standard in the diagnosis of neglected tropical diseases. As resource limited, rural areas often lack laboratory equipment and trained personnel, new diagnostic techniques are needed. Low-cost, point-of-care imaging devices show potential in the diagnosis of these diseases. Novel, digital image analysis algorithms can be utilized to automate sample analysis. Objective: Evaluation of the imaging performance of a miniature digital microscopy scanner for the diagnosis of soil-transmitted helminths and Schistosoma haematobium, and training of a deep learning-based image analysis algorithm for automated detection of soil-transmitted helminths in the captured images. Methods: A total of 13 iodine-stained stool samples containing Ascaris lumbricoides, Trichuris trichiura and hookworm eggs and 4 urine samples containing Schistosoma haematobium were digitized using a reference whole slide-scanner and the mobile microscopy scanner. Parasites in the images were identified by visual examination and by analysis with a deep learning-based image analysis algorithm in the stool samples. Results were compared between the digital and visual analysis of the images showing helminth eggs. Results: Parasite identification by visual analysis of digital slides captured with the mobile microscope was feasible for all analyzed parasites. Although the spatial resolution of the reference slide-scanner is higher, the resolution of the mobile microscope is sufficient for reliable identification and classification of all parasites studied. Digital image analysis of stool sample images captured with the mobile microscope showed high sensitivity for detection of all helminths studied (range of sensitivity = 83.3–100%) in the test set (n = 217) of manually labeled helminth eggs. Conclusions: In this proof-of-concept study, the imaging performance of a mobile, digital microscope was sufficient for visual detection of soil-transmitted helminths and Schistosoma haematobium. Furthermore, we show that deep learning-based image analysis can be utilized for the automated detection and classification of helminths in the captured images. PMID:28838305

A Duo of Potassium-Responsive Histidine Kinases Govern the Multicellular Destiny of Bacillus subtilis

PubMed Central

de Oña, Paula; Kunert, Maritta; Leñini, Cecilia; Gallegos-Monterrosa, Ramses; Mhatre, Eisha; Vileta, Darío; Hölscher, Theresa; Kuipers, Oscar P.

2015-01-01

ABSTRACT Multicellular biofilm formation and surface motility are bacterial behaviors considered mutually exclusive. However, the basic decision to move over or stay attached to a surface is poorly understood. Here, we discover that in Bacillus subtilis, the key root biofilm-controlling transcription factor Spo0A~Pi (phosphorylated Spo0A) governs the flagellum-independent mechanism of social sliding motility. A Spo0A-deficient strain was totally unable to slide and colonize plant roots, evidencing the important role that sliding might play in natural settings. Microarray experiments plus subsequent genetic characterization showed that the machineries of sliding and biofilm formation share the same main components (i.e., surfactin, the hydrophobin BslA, exopolysaccharide, and de novo-formed fatty acids). Sliding proficiency was transduced by the Spo0A-phosphorelay histidine kinases KinB and KinC. We discovered that potassium, a previously known inhibitor of KinC-dependent biofilm formation, is the specific sliding-activating signal through a thus-far-unnoticed cytosolic domain of KinB, which resembles the selectivity filter sequence of potassium channels. The differential expression of the Spo0A~Pi reporter abrB gene and the different levels of the constitutively active form of Spo0A, Sad67, in Δspo0A cells grown in optimized media that simultaneously stimulate motile and sessile behaviors uncover the spatiotemporal response of KinB and KinC to potassium and the gradual increase in Spo0A~Pi that orchestrates the sequential activation of sliding, followed by sessile biofilm formation and finally sporulation in the same population. Overall, these results provide insights into how multicellular behaviors formerly believed to be antagonistic are coordinately activated in benefit of the bacterium and its interaction with the host. PMID:26152584

Issues for application of virtual microscopy to cytoscreening, perspectives based on questionnaire to Japanese cytotechnologists

PubMed Central

Mori, Ichiro; Nunobiki, Osamu; Ozaki, Takashi; Taniguchi, Emiko; Kakudo, Kennichi

2008-01-01

To clarify the issues associated with the applications of virtual microscopy to the daily cytology slide screening, we conducted a survey at a slide conference of cytology. The survey was conducted specifically to the Japanese cytology technologists who use microscopes on a routine basis. Virtual slides (VS) were prepared from cytology slides using NanoZoomer (Hamamatsu Photonics, Japan), which is capable of adjusting focus on any part of the slide. A total of ten layers were scanned from the same slides, with 2 micrometer intervals. To simulate the cytology slide screening, no marker points were created. The total data volume of six slides was approximately 25 Giga Bytes. The slides were stored on the Windows 2003 Server, and were made accessible on the web to the cytology technologists. Most cytotechnologists answered "Satisfied" or "Acceptable" to the VS resolution and drawing speed, and "Dissatisfied" to the operation speed. To the ten layered focus, an answer "insufficient" was slightly more frequent than the answer "sufficient", while no one answered "fewer is acceptable" or "no need for depth". As for the use of cytology slide screening, answers "usable, but requires effort" and "not usable" were about equal in number. In a Japanese cytology meeting, a unique VS system has been used in slide conferences with markings to the discussion point for years. Therefore, Japanese cytotechnologists are relatively well accustomed to the use of VS, and the survey results showed that they regarded VS more positively than we expected. Currently, VS has the acceptable resolution and drawing speed even on the web. Most cytotechnologists regard the focusing capability crucial for cytology slide screening, but the consequential enlargement of data size, longer scanning time, and slower drawing speed are the issues that are yet to be resolved. PMID:18673503

Automated complete slide digitization: a medium for simultaneous viewing by multiple pathologists.

PubMed

Leong, F J; McGee, J O

2001-11-01

Developments in telepathology robotic systems have evolved the concept of a 'virtual microscope' handling 'digital slides'. Slide digitization is a method of archiving salient histological features in numerical (digital) form. The value and potential of this have begun to be recognized by several international centres. Automated complete slide digitization has application at all levels of clinical practice and will benefit undergraduate, postgraduate, and continuing education. Unfortunately, as the volume of potential data on a histological slide represents a significant problem in terms of digitization, storage, and subsequent manipulation, the reality of virtual microscopy to date has comprised limited views at inadequate resolution. This paper outlines a system refined in the authors' laboratory, which employs a combination of enhanced hardware, image capture, and processing techniques designed for telepathology. The system is able to scan an entire slide at high magnification and create a library of such slides that may exist on an internet server or be distributed on removable media (such as CD-ROM or DVD). A digital slide allows image data manipulation at a level not possible with conventional light microscopy. Combinations of multiple users, multiple magnifications, annotations, and addition of ancillary textual and visual data are now possible. This demonstrates that with increased sophistication, the applications of telepathology technology need not be confined to second opinion, but can be extended on a wider front. Copyright 2001 John Wiley & Sons, Ltd.

Coated Rectangular Composite Archwires: A Comparison Of Self-Ligating And Conventional Bracket Systems During Sliding Mechanics

NASA Astrophysics Data System (ADS)

Woods, David Keith

The purpose of this study was to analyze the resistance to sliding of coated rectangular fiber reinforced composite archwires using various brackets systems and second-order bracket angulations. Resistance to sliding was investigated for eight bracket systems: six self-ligating brackets (four passive and two passive-active) and two conventional brackets. A rectangular fiber reinforced composite archwire of 0.019 x 0.025-in dimension from BiomersRTM SimpliClear was drawn through a three-bracket model system at ten millimeters per minute for 2.5 millimeters. For each bracket, the resistance to sliding was measured at four bracket angulations (0°, 2.5°, 5°, and 10°) in a dry state at room temperature. The fiber reinforced composite archwire produced the lowest sliding resistance with the passive self-ligating bracket system (Damon DQ) at each bracket angulation tested. Overall, self-ligating bracket systems generated lower sliding resistance than conventionally ligated systems, and one passive/active self-ligating bracket system (In-Ovation-R). There was a significant increase in resistance to sliding as bracket angulation increased for all bracket systems tested. Microscopic analysis revealed increased perforation of the archwire coating material as bracket angulations were increased. Our findings show that the rectangular fiber reinforced composite archwire may be acceptable for sliding mechanics during the intermediate stages of orthodontic tooth movement, however more long-term studies are needed.

Detection of fungal hyphae using smartphone and pocket magnifier: going cellular.

PubMed

Agarwal, Tushar; Bandivadekar, Pooja; Satpathy, Gita; Sharma, Namrata; Titiyal, Jeewan S

2015-03-01

The aim of this study was to detect fungal hyphae in a corneal scraping sample using a cost-effective assembly of smartphone and pocket magnifier. In this case report, a tissue sample was obtained by conventional corneal scraping from a clinically suspicious case of mycotic keratitis. The smear was stained with Gram stain, and a 10% potassium hydroxide mount was prepared. It was imaged using a smartphone coupled with a compact pocket magnifier and integrated light-emitting diode assembly at point-of-care. Photographs of multiple sections of slides were viewed using smartphone screen and pinch-to-zoom function. The same slides were subsequently screened under a light microscope by an experienced microbiologist. The scraping from the ulcer was also inoculated on blood agar and Sabouraud dextrose agar. Smartphone-based digital imaging revealed the presence of gram-positive organism with hyphae. Examination under a light microscope also yielded similar findings. Fusarium was cultured from the corneal scraping, confirming the diagnosis of mycotic keratitis. The patient responded to topical 5% natamycin therapy, with resolution of the ulcer after 4 weeks. Smartphones can be successfully used as novel point-of-care, cost-effective, reliable microscopic screening tools.

Sex on a slide: Antoine Lacassagne and the search for a microscopic definition of masculinity and femininity.

PubMed

Löwy, Ilana

2013-01-01

In 1919, the French pathologist and pioneer of radiotherapy of cancer, Antoine Lacassagne, studied the case of a young man of indeterminate sexuality (a condition later named "intersex," and recently renamed, "disorders of sexual development"). Lacassagne's argument that the patient was a "true" hermaphrodite, that is, an individual who possesses at the same time male and female sexual glands, was grounded exclusively in his study of microscopic preparations. Such preparations were seen as the definitive proof of the "true biological sex" of a given person, seen as a fixed entity. On the other hand, Lacassagne's definition of biological, or rather histological sex, was dissociated from sexuality, sexual orientation and sex/gender identity. In the 1930s, the isolation of sex hormones made it possible to modulate specific sexual traits, thus destabilizing the concept of a fixed biological sex. It did not undermine, however, the central role of histological proofs. Sex on a slide continued to be seen as definitive evidence of the "true" sexual identity of an individual, but from the 1930s this proof was valid only for the time when a given microscopic preparation had been manufactured.

Novel method for the high-throughput processing of slides for the comet assay

PubMed Central

Karbaschi, Mahsa; Cooke, Marcus S.

2014-01-01

Single cell gel electrophoresis (the comet assay), continues to gain popularity as a means of assessing DNA damage. However, the assay's low sample throughput and laborious sample workup procedure are limiting factors to its application. “Scoring”, or individually determining DNA damage levels in 50 cells per treatment, is time-consuming, but with the advent of high-throughput scoring, the limitation is now the ability to process significant numbers of comet slides. We have developed a novel method by which multiple slides may be manipulated, and undergo electrophoresis, in batches of 25 rather than individually and, importantly, retains the use of standard microscope comet slides, which are the assay convention. This decreases assay time by 60%, and benefits from an electrophoresis tank with a substantially smaller footprint, and more uniform orientation of gels during electrophoresis. Our high-throughput variant of the comet assay greatly increases the number of samples analysed, decreases assay time, number of individual slide manipulations, reagent requirements and risk of damage to slides. The compact nature of the electrophoresis tank is of particular benefit to laboratories where bench space is at a premium. This novel approach is a significant advance on the current comet assay procedure. PMID:25425241

Novel method for the high-throughput processing of slides for the comet assay.

PubMed

Karbaschi, Mahsa; Cooke, Marcus S

2014-11-26

Single cell gel electrophoresis (the comet assay), continues to gain popularity as a means of assessing DNA damage. However, the assay's low sample throughput and laborious sample workup procedure are limiting factors to its application. "Scoring", or individually determining DNA damage levels in 50 cells per treatment, is time-consuming, but with the advent of high-throughput scoring, the limitation is now the ability to process significant numbers of comet slides. We have developed a novel method by which multiple slides may be manipulated, and undergo electrophoresis, in batches of 25 rather than individually and, importantly, retains the use of standard microscope comet slides, which are the assay convention. This decreases assay time by 60%, and benefits from an electrophoresis tank with a substantially smaller footprint, and more uniform orientation of gels during electrophoresis. Our high-throughput variant of the comet assay greatly increases the number of samples analysed, decreases assay time, number of individual slide manipulations, reagent requirements and risk of damage to slides. The compact nature of the electrophoresis tank is of particular benefit to laboratories where bench space is at a premium. This novel approach is a significant advance on the current comet assay procedure.

Carbon Displacement-Induced Single Carbon Atomic Chain Formation and its Effects on Sliding of SiC Fibers in SiC/graphene/SiC Composite

DOE PAGES

Wallace, Joseph B.; Chen, Di; Shao, Lin

2015-11-03

Understanding radiation effects on the mechanical properties of SiC composites is important to their application in advanced reactor designs. By means of molecular dynamics simulations, we found that due to strong interface bonding between the graphene layers and SiC, the sliding friction of SiC fibers is largely determined by the frictional behavior between graphene layers. Upon sliding, carbon displacements between graphene layers can act as seed atoms to induce the formation of single carbon atomic chains (SCACs) by pulling carbon atoms from the neighboring graphene planes. The formation, growth, and breaking of SCACs determine the frictional response to irradiation.

Comparison of four DNA extraction methods for the detection of Mycobacterium leprae from Ziehl-Neelsen-stained microscopic slides.

PubMed

Ruiz-Fuentes, Jenny Laura; Díaz, Alexis; Entenza, Anayma Elena; Frión, Yahima; Suárez, Odelaisy; Torres, Pedro; de Armas, Yaxsier; Acosta, Lucrecia

2015-12-01

The diagnosis of leprosy has been a challenge due to the low sensibility of the conventional methods and the impossibility of culturing the causative organism. In this study, four methods for Mycobacterium leprae nucleic-acid extraction from Ziehl-Neelsen-stained slides (ZNS slides) were compared: Phenol/chloroform, Chelex 100 resin, and two commercial kits (Wizard Genomic DNA Purification Kit and QIAamp DNA Mini Kit). DNA was extracted from four groups of slides: a high-codification-slide group (bacteriological index [BI]⩾4), a low-codification-slide group (BI=1), a negative-slide group (BI=0), and a negative-control-slide group (BI=0). Quality DNA was evidenced by the amplification of specific repetitive element present in M. leprae genomic DNA (RLEP) using a nested polymerase chain reaction. This is the first report comparing four different extraction methods for obtaining M. leprae DNA from ZNS slides in Cuban patients, and applied in molecular diagnosis. Good-quality DNA and positive amplification were detected in the high-codification-slide group with the four methods, while from the low-codification-slide group only the QIAGEN and phenol-chloroform methods obtained amplification of M. leprae. In the negative-slide group, only the QIAGEN method was able to obtain DNA with sufficient quality for positive amplification of the RLEP region. No amplification was observed in the negative-control-slide group by any method. Patients with ZNS negative slides can still transmit the infection, and molecular methods can help identify and treat them, interrupting the chain of transmission and preventing the onset of disabilities. The ZNS slides can be sent easily to reference laboratories for later molecular analysis that can be useful not only to improve the diagnosis, but also for the application of other molecular techniques. Copyright © 2015 Asian-African Society for Mycobacteriology. Published by Elsevier Ltd. All rights reserved.

Method for making thin polypropylene film

DOEpatents

Behymer, R.D.; Scholten, J.A.

1985-11-21

An economical method is provided for making uniform thickness polypropylene film as thin as 100 Angstroms. A solution of polypropylene dissolved in xylene is formed by mixing granular polypropylene and xylene together in a flask at an elevated temperature. A substrate, such as a glass plate or microscope slide is immersed in the solution. When the glass plate is withdrawn from the solution at a uniform rate, a thin polypropylene film forms on a flat surface area of the glass plate as the result of xylene evaporation. The actual thickness of the polypropylene film is functional of the polypropylene in xylene solution concentration, and the particular withdrawal rate of the glass plate from the solution. After formation, the thin polypropylene film is floated from the glass plate onto the surface of water, from which it is picked up with a wire hoop.

Operation and Performance of the Mars Exploration Rover Imaging System on the Martian Surface

NASA Technical Reports Server (NTRS)

Maki, Justin N.; Litwin, Todd; Herkenhoff, Ken

2005-01-01

This slide presentation details the Mars Exploration Rover (MER) imaging system. Over 144,000 images have been gathered from all Mars Missions, with 83.5% of them being gathered by MER. Each Rover has 9 cameras (Navcam, front and rear Hazcam, Pancam, Microscopic Image, Descent Camera, Engineering Camera, Science Camera) and produces 1024 x 1024 (1 Megapixel) images in the same format. All onboard image processing code is implemented in flight software and includes extensive processing capabilities such as autoexposure, flat field correction, image orientation, thumbnail generation, subframing, and image compression. Ground image processing is done at the Jet Propulsion Laboratory's Multimission Image Processing Laboratory using Video Image Communication and Retrieval (VICAR) while stereo processing (left/right pairs) is provided for raw image, radiometric correction; solar energy maps,triangulation (Cartesian 3-spaces) and slope maps.

Standardization of blood smears prepared in transparent acetate: an alternative method for the microscopic diagnosis of malaria.

PubMed

Mello, Marcia B C; Luz, Francisco C; Leal-Santos, Fabio A; Alves, Eduardo R; Gasquez, Thamires M; Fontes, Cor J F

2014-06-17

Due to students' initial inexperience, slides are frequently broken and blood smears are damaged in microscopy training, leading to the need for their constant replacement. To minimize this problem a method of preparing blood smears on transparent acetate sheets was developed with the goal of implementing appropriate and more readily available teaching resources for the microscopic diagnosis of malaria. Acetate sheets derived from polyester were used to standardize the preparation and staining of thin and thick blood smears on transparent acetate sheets. Thick and thin blood smears were also prepared using the conventional method on glass slides. The staining was conducted using Giemsa staining for the thick and thin smears. Microscopic examination (1,000x) of the thin and thick blood smears prepared on transparent acetate produced high-quality images for both the parasites and the blood cells. The smears showed up on a clear background and with minimal dye precipitation. It was possible to clearly identify the main morphological characteristics of Plasmodium, neutrophils and platelets. After 12 months of storage, there was no change in image quality or evidence of fungal colonization. Preparation of thin and thick blood smears in transparent acetate for the microscopic diagnosis of malaria does not compromise the morphological and staining characteristics of the parasites or blood cells. It is reasonable to predict the applicability of transparent acetate in relevant situations such as the training of qualified professionals for the microscopic diagnosis of malaria and the preparation of positive specimens for competency assessment (quality control) of professionals and services involved in the diagnosis of malaria.

Rapid alkaline methylene blue supravital staining for assessment of anterior segment infections.

PubMed

Kiuchi, Katsuji

2016-01-01

To present the Löffler's alkaline methylene blue technique of staining eye discharges in eyes with anterior segment infections. The Löffler's alkaline methylene blue staining method is a simple staining technique that can be used to differentiate bacterial, viral, and fungal infections. It is a cationic dye that stains cells blue because the positively charged dye is attracted to negatively charged particles such as polyphosphates, DNAs, and RNAs. Specimens collected from patients by swabbing are smeared onto microscope slides and the methylene blue solution is dropped on the slide. The slide is covered with a glass cover slip and examined under a microscope. The entire time from the collection to the viewing is about 30 seconds. Histopathological images of the conjunctival epithelial cells and neutrophils in eye discharges were dyed blue and the nuclei were stained more intensely blue. Bacterial infections consisted mainly of neutrophils, and viral infections consisted mainly of lymphocytes. Löffler's alkaline methylene blue staining can be done in about 30 seconds for diagnosis. Even though this is a one color stain, it is possible to infer the cause of the infection by detection of the absence of bacteria and/or fungi in context of the differential distribution of neutrophils and lymphocytes.

Web-based virtual microscopy at the RWTH Aachen University: didactic concept, methods and analysis of acceptance by the students.

PubMed

Merk, Magdalene; Knuechel, Ruth; Perez-Bouza, Alberto

2010-12-20

Fundamental knowledge of microscopic anatomy and pathology has always been an essential part in medical education. The traditional didactic concept comprises theoretical and practical lessons using a light microscope and glass slides. High-speed Internet connections and technical improvement in whole-slide digital microscopy (commonly termed "virtual microscopy") provide a new and attractive approach for both teachers and students. High picture quality and unlimited temporal and spatial availability of histology samples from different fields are key advantages of web-based digital microscopy. In this report we discuss the technical requirements, system efficiency, optical resolution and didactic concept. Furthermore, we present a review of the experience gained in the course of one year based on an analysis of student acceptance. Three groups with a total of 192 students between the 3rd and 5th year of medical studies attending the practical courses of general and advanced histopathology had access to both glass-mounted and digitalized slides. Prior to exams, students were asked to answer an anonymous questionnaire. The results of the study reflect the high acceptance and intensive use of the web-based digital histology by students, thus encouraging the development of further Web-based learning strategies for the teaching of histology and pathology. 2010 Elsevier GmbH. All rights reserved.

Resolution of 90 nm (lambda/5) in an optical transmission microscope with an annular condenser.

PubMed

Vainrub, Arnold; Pustovyy, Oleg; Vodyanoy, Vitaly

2006-10-01

Resolution of 90 nm was achieved with a research microscope simply by replacing the standard bright-field condenser with a homebuilt illumination system with a cardioid annular condenser. Diffraction gratings with 100 nm width lines as well as less than 100 nm size features of different-shaped objects were clearly visible on a calibrated microscope test slide. The resolution increase results from a known narrower diffraction pattern in coherent illumination for the annular aperture compared with the circular aperture. This explanation is supported by an excellent accord of calculated and measured diffraction patterns for a 50 nm radius disk.

[Quality assessment of microscopic examination in tuberculosis diagnostic laboratories: a preliminary study].

PubMed

Simşek, Hülya; Ceyhan, Ismail; Tarhan, Gülnur; Güner, Uğur

2010-10-01

Recently, the diagnosis of pulmonary tuberculosis (TB) has based on smear microscopy in the Direct Observed Treatment Strategy (DOTS) programme which provides the basis of treatment worldwide. Microscopic detection of AFB (Acid-Fast Bacilli) is one of the main components in the National TB Control Programmes (NTCP). Precision level in microscopy procedures and evaluations are the most important steps for accurate diagnosis of the disease and to initiate proper treatment. Therefore, the external quality assessment (EQA) is the most important implement to provide the reliability and validity of tests. In countries where NTCP are performed, this task is fulfilled by the National Reference Laboratories (NRL) according to the guidelines of the World Health Organization (WHO). For this purpose a pilot study was initiated by the central NRL of Turkey for EQA of AFB smear microscopy as part of the NTCP on January 1, 2005. A total of 5 laboratories of which 2 were district TB laboratories (A, B), 2 were tuberculosis control dispensaries (C, D), 1 was a national reference laboratory (E), participated in this study. Blind re-checking method (re-examination of randomly selected slides) was used for the evaluation, and the slides were sent to the central NRL with 3 months interval, four times a year, selected according to LQAS (Lot Quality Assurance Sampling) guides. In the re-evaluation of the slides, false positivity (FP), false negativity (FN) and quantification errors (QE) were noted. Laboratory A, sent totally 525 slides between January 1, 2005 and April 1, 2008. In the result of re-checking, 514 (97.9%) slides were found concordant, and 11 (2.1%) were discordant (10 FP, 1 FN). Laboratory B, participated in the study between October 1, 2005 and July 1, 2006 and of the 67 re-examined slides, 60 (89.5%) were concordant and 7 (10.5%) were discordant (2 FP, 0 FN, 5 QE). Laboratory C, sent 235 slides between January 1, 2005 and April 1, 2006; of them 218 (92.8%) were detected as compatible and 17 (7.2%) slides were incompatible (4 FP, 9 FN, 4 QE). Laboratory D, participated in QC for only once between January 1, 2008 and April 1, 2008; and all the 50 slides were found compatible, with no FP, FN and QE. Laboratory E, was included in the study between January 1, 2005 and January 1, 2008 and of the 696 re-checked slides, 690 (99.1%) were reported as compatible and 6 (0.9%) were incompatible (3 FN, 3 QE). Following EQA, on-site evaluation of the laboratories with major errors, was performed and necessary adjustments and training were done. In conclusion, external quality control measures for AFB microscopy is crucial and essential for the tuberculosis laboratory performances for accurate and reliable results.

Automated sample area definition for high-throughput microscopy.

PubMed

Zeder, M; Ellrott, A; Amann, R

2011-04-01

High-throughput screening platforms based on epifluorescence microscopy are powerful tools in a variety of scientific fields. Although some applications are based on imaging geometrically defined samples such as microtiter plates, multiwell slides, or spotted gene arrays, others need to cope with inhomogeneously located samples on glass slides. The analysis of microbial communities in aquatic systems by sample filtration on membrane filters followed by multiple fluorescent staining, or the investigation of tissue sections are examples. Therefore, we developed a strategy for flexible and fast definition of sample locations by the acquisition of whole slide overview images and automated sample recognition by image analysis. Our approach was tested on different microscopes and the computer programs are freely available (http://www.technobiology.ch). Copyright © 2011 International Society for Advancement of Cytometry.

Directional acceleration vector-driven displacement of fluids (DAVD-DOF)

NASA Technical Reports Server (NTRS)

Clarke, Mark S. F. (Inventor); Feeback, Daniel L. (Inventor)

2004-01-01

Centrifugal analyzer and method for staining biological or non-biological samples in microgravity, wherein the method utilizes an increase in weight of a fluid sample as a function of g-load, to overcome cohesive and frictional forces from preventing its movement in a preselected direction. Apparatus is characterized by plural specimen reservoirs and channels in a slide, each channel being of differing cross-section, wherein respective samples are selectively dispensed, from the reservoirs in response to an imposed g-factor, precedent to sample staining. Within the method, one thus employs microscope slides which define channels, each being of a differing cross-section dimension relative to others. In combination therewith, centrifugal slide mounting apparatus controllably imposes g-vectors of differing magnitudes within a defined structure of the centrifuge such as a chip array.

Digital microscopy. Bringing new technology into focus.

PubMed

2010-06-01

Digital microscopy enables the scanning of microscope slides so that they can be viewed, analyzed, and archived on a computer. While the technology is not yet widely accepted by pathologists, a switch to digital microscopy systems seems to be inevitable in the near future.

Technology-Enhanced Pathology Education: Nigerian Medical Students Perspectives

ERIC Educational Resources Information Center

Vhriterhire, Raymond A.; Orkuma, Joseph A.; Jegede, Olushola O.; Omotosho, Ayodele J.; Adekwu, Amali

2016-01-01

The delivery of pathology education traditionally through instructor centred didactic lectures, small group tutorials, and practical demonstrations using microscope glass slides, gross pot specimens and autopsy sessions, is paving way for electronic learner-centred methods. Successful adoption and implementation of rapidly advancing educational…

Revising the Redundancy Principle in Multimedia Learning

ERIC Educational Resources Information Center

Mayer, Richard E.; Johnson, Cheryl I.

2008-01-01

College students viewed a short multimedia PowerPoint presentation consisting of 16 narrated slides explaining lightning formation (Experiment 1) or 8 narrated slides explaining how a car's braking system works (Experiment 2). Each slide appeared for approximately 8-10 s and contained a diagram along with 1-2 sentences of narration spoken in a…

Dry sliding behavior of aluminum alloy 8011 with 12% fly ash composites

NASA Astrophysics Data System (ADS)

Magibalan, S.; Senthilkumar, P.; Palanivelu, R.; Senthilkumar, C.; Shivasankaran, N.; Prabu, M.

2018-05-01

This research focused on the fabrication of aluminum alloy 8011 with 12% fly ash (FA) composite (AA8011%–12% FA) using the stir casting method. A three-level central composite design experiment was developed using response surface methodology with various parameters such as load, time, and sliding velocity varied in the range of 5 to 15 N, 5 to 15 min, and 1.5 to 4.5 m.s‑1, respectively. Dry sliding wear tests were performed as per the experimental design using a pin on disc at room temperature. The obtained regression result indicated that the developed model performed well in relating the wear process parameters and predicted the wear behavior of the composite. The surface plot showed that the wear rate increases with increase in load, time, and sliding velocity. Hardness was evaluated by Vickers hardness testing machine. Moreover, the surface morphology of the worn-out composite was examined using a scanning electron microscope.

Stress Measurement by Geometrical Optics

NASA Technical Reports Server (NTRS)

Robinson, R. S.; Rossnagel, S. M.

1986-01-01

Fast, simple technique measures stresses in thin films. Sample disk bowed by stress into approximately spherical shape. Reflected image of disk magnified by amount related to curvature and, therefore, stress. Method requires sample substrate, such as cheap microscope cover slide, two mirrors, laser light beam, and screen.

From microscopy to whole slide digital images: a century and a half of image analysis.

PubMed

Taylor, Clive R

2011-12-01

In the year 1850, microscopes had evolved in quality to the point that the "first pathologists emerged from the treacherous swamps of medieval practice onto the relatively firm ground that histopathology seemed to offer." These early pathologists began to practice the art of image analysis, and diagnostic surgical pathology was born. Today the traditional microscope, in the hands of an experienced pathologist, is established as the gold standard for diagnosis of cancer and other diseases. Nonetheless, it is a tool and a technology that is more than 150 years old. Rapid advances in the capabilities of digital imaging hardware and software now offer the real possibility of moving to a new level of practice, using whole slide digital images for diagnosis, education, and research in morphologic pathology. Potential efficiencies in work flow and diagnostic integration, coupled with the use of powerful new analytic methods, promise radically to change the future shape of surgical pathology.

A sparse representation of the pathologist's interaction with whole slide images to improve the assigned relevance of regions of interest

NASA Astrophysics Data System (ADS)

Santiago, Daniel; Corredor, Germán.; Romero, Eduardo

2017-11-01

During a diagnosis task, a Pathologist looks over a Whole Slide Image (WSI), aiming to find out relevant pathological patterns. Nonetheless, a virtual microscope captures these structures, but also other cellular patterns with different or none diagnostic meaning. Annotation of these images depends on manual delineation, which in practice becomes a hard task. This article contributes a new method for detecting relevant regions in WSI using the routine navigations in a virtual microscope. This method constructs a sparse representation or dictionary of each navigation path and determines the hidden relevance by maximizing the incoherence between several paths. The resulting dictionaries are then projected onto each other and relevant information is set to the dictionary atoms whose similarity is higher than a custom threshold. Evaluation was performed with 6 pathological images segmented from a skin biopsy already diagnosed with basal cell carcinoma (BCC). Results show that our proposal outperforms the baseline by more than 20%.

Virtual slides in peer reviewed, open access medical publication.

PubMed

Kayser, Klaus; Borkenfeld, Stephan; Goldmann, Torsten; Kayser, Gian

2011-12-19

Application of virtual slides (VS), the digitalization of complete glass slides, is in its infancy to be implemented in routine diagnostic surgical pathology and to issues that are related to tissue-based diagnosis, such as education and scientific publication. Electronic publication in Pathology offers new features of scientific communication in pathology that cannot be obtained by conventional paper based journals. Most of these features are based upon completely open or partly directed interaction between the reader and the system that distributes the article. One of these interactions can be applied to microscopic images allowing the reader to navigate and magnify the presented images. VS and interactive Virtual Microscopy (VM) are a tool to increase the scientific value of microscopic images. The open access journal Diagnostic Pathology http://www.diagnosticpathology.org has existed for about five years. It is a peer reviewed journal that publishes all types of scientific contributions, including original scientific work, case reports and review articles. In addition to digitized still images the authors of appropriate articles are requested to submit the underlying glass slides to an institution (DiagnomX.eu, and Leica.com) for digitalization and documentation. The images are stored in a separate image data bank which is adequately linked to the article. The normal review process is not involved. Both processes (peer review and VS acquisition) are performed contemporaneously in order to minimize a potential publication delay. VS are not provided with a DOI index (digital object identifier). The first articles that include VS were published in March 2011. Several logistic constraints had to be overcome until the first articles including VS could be published. Step by step an automated acquisition and distribution system had to be implemented to the corresponding article. The acceptance of VS by the reader is high as well as by the authors. Of specific value are the increased confidence to and reputation of authors as well as the presented information to the reader. Additional associated functions such as access to author-owned related image collections, reader-controlled automated image measurements and image transformations are in preparation. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1232133347629819.

Virtual slides in peer reviewed, open access medical publication

PubMed Central

2011-01-01

Background Application of virtual slides (VS), the digitalization of complete glass slides, is in its infancy to be implemented in routine diagnostic surgical pathology and to issues that are related to tissue-based diagnosis, such as education and scientific publication. Approach Electronic publication in Pathology offers new features of scientific communication in pathology that cannot be obtained by conventional paper based journals. Most of these features are based upon completely open or partly directed interaction between the reader and the system that distributes the article. One of these interactions can be applied to microscopic images allowing the reader to navigate and magnify the presented images. VS and interactive Virtual Microscopy (VM) are a tool to increase the scientific value of microscopic images. Technology and Performance The open access journal Diagnostic Pathology http://www.diagnosticpathology.org has existed for about five years. It is a peer reviewed journal that publishes all types of scientific contributions, including original scientific work, case reports and review articles. In addition to digitized still images the authors of appropriate articles are requested to submit the underlying glass slides to an institution (DiagnomX.eu, and Leica.com) for digitalization and documentation. The images are stored in a separate image data bank which is adequately linked to the article. The normal review process is not involved. Both processes (peer review and VS acquisition) are performed contemporaneously in order to minimize a potential publication delay. VS are not provided with a DOI index (digital object identifier). The first articles that include VS were published in March 2011. Results and Perspectives Several logistic constraints had to be overcome until the first articles including VS could be published. Step by step an automated acquisition and distribution system had to be implemented to the corresponding article. The acceptance of VS by the reader is high as well as by the authors. Of specific value are the increased confidence to and reputation of authors as well as the presented information to the reader. Additional associated functions such as access to author-owned related image collections, reader-controlled automated image measurements and image transformations are in preparation. Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1232133347629819. PMID:22182763

A comparison of microscopic ink characteristics of 35 commercially available surgical margin inks.

PubMed

Milovancev, Milan; Löhr, Christiane V; Bildfell, Robert J; Gelberg, Howard B; Heidel, Jerry R; Valentine, Beth A

2013-11-01

To compare microscopic characteristics of commercially available surgical margin inks used for surgical pathology specimens. Prospective in vitro study. Thirty-five different surgical margin inks (black, blue, green, orange, red, violet, and yellow from 5 different manufacturers). Inks were applied to uniform, single-source, canine cadaveric full-thickness ventral abdominal tissue blocks. Tissue blocks and ink manufacturers were randomly paired and each color was applied to a length of the cut tissue margin. After drying, tissues were fixed in formalin, and 3 radial slices were obtained from each color section and processed for routine histologic evaluation, yielding 105 randomly numbered slides with each manufacturer's color represented in triplicate. Slides were evaluated by 5 blinded, board-certified veterinary anatomic pathologists using a standardized scoring scheme. Statistical analyses were performed to evaluate for ink manufacturer effects on scores, correlation among different subjective variables, and pathologist agreement. Black and blue had the most consistently high scores whereas red and violet had the most consistently low overall scores, across all manufacturers. All colors tested, except yellow, had statistically significant differences in overall scores among individual manufacturers. Overall score was significantly correlated to all other subjective microscopic scores evaluated. The average Spearman correlation coefficient among the 10 pairwise pathologists overall ink scores was 0.60. There are statistically significant differences in microscopic ink characteristics among manufacturers, with a notable degree of inter-pathologist agreement. © Copyright 2013 by The American College of Veterinary Surgeons.

Malignant melanoma. Prognostic significance of "microscopic satellites" in the reticular dermis and subcutaneous fat.

PubMed Central

Day, C L; Harrist, T J; Gorstein, F; Sober, A J; Lew, R A; Friedman, R J; Pasternack, B S; Kopf, A W; Fitzpatrick, T B; Mihm, M C

1981-01-01

A review of the microscope slides of the primary tumors for 596 patients with clinical Stage I melanoma revealed that primary lesions displayed two distinct patterns of invasion: 1) single cell invasion with direct extension of the main body of tumor into the reticular dermis or subcutaneous fat, and 2) invasion with "microscope satellites" (i.e. discrete tumor nests greater than 0.05 mm in diameter, that were separated from the main body of the tumor by normal reticular dermal collagen or subcutaneous fat). The five-year disease free survival rate for 95 patients with "microscopic satellites" was 36% +/- 6%. This is in contrast to a five-year disease free survival rate of 89% +/- 2% for 501 patients without these satellites (p = 4.3 x 10(-29), generalized Wilcoxon test). "Microscopic satellites" (present vs absent) was comparable to histologic ulceration in its additive prognostic effect of tumor thickness (Breslow). PMID:7247529

Prediction of scuffing failure based on competitive kinetics of oxide formation and removal: Application to lubricated sliding of AISI 52100 steel on steel

NASA Astrophysics Data System (ADS)

Cutiongco, Eric C.; Chung, Yip-Wah

1994-07-01

A method for predicting scuffing failure based on the competitive kinetics of oxide formation and removal has been developed and applied to the sliding of AISI 52100 steel on steel with poly-alpha-olefin as the lubricant. Oxide formation rates were determining using static oxidation tests on coupons of 52100 steel covered with poly-alpha-olefin at temperatures of 140 C to 250 C. Oxide removal rates were determined at different combinations of initial average nominal contact pressures (950 MPa to 1578 MPa) and sliding velocities (0.4 m/s to 1.8 m/s) using a ball-on-disk vacuum tribotester. The nominal asperity flash temperatures generated during the wear tests were calculated and the temperatures corresponding to the intersection of the the Arrhenius plots of oxide formation and removal rates were determined and taken as the critical failure temperatures. The pressure-velocity failure transition diagram was constructed by plotting the critical failure temperatures along isotherms of average nominal asperity flash temperatures calculated at different combinations of contact stress and sliding speed. The predicted failure transition curve agreed well with experimental scuffing data.

Immediate assessment of performance of medical laboratory scientists following a 10-day malaria microscopy training programme in Nigeria.

PubMed

Aiyenigba, Bolatito; Ojo, Abiodun; Aisiri, Adolor; Uzim, Justus; Adeusi, Oluwole; Mwenesi, Halima

2017-01-01

Rapid and precise diagnosis of malaria is an essential element in effective case management and control of malaria. Malaria microscopy is used as the gold standard for malaria diagnosis, however results remain poor as positivity rate in Nigeria is consistently over 90%. The United States President's Malaria Initiative (PMI) through the Malaria Action Program for States (MAPS) supported selected states in Nigeria to build capacity for malaria microscopy. This study demonstrates the effectiveness of in-service training on malaria microscopy amongst medical laboratory scientists. The training was based on the World Health Organization (WHO) basic microscopy training manual. The 10-day training utilized a series of didactic lectures and examination of teaching slides using a CX 21 Olympus binocular microscope. All 108 medical laboratory scientists trained from 2012 to 2015 across five states in Nigeria supported by PMI were included in the study. Evaluation of the training using a pre-and post-test method was based on written test questions; reading photographic slide images of malaria parasites; and prepared slides. There was a significant improvement in the mean written pre-and post-tests scores from 37.9% (95% CI 36.2-39.6%) to 70.7% (95% CI 68.4-73.1%) ( p  < 0.001). The mean counting post-test score improved significantly from 4.2% (95% CI 2.6-5.7%) to 27.9% (95% CI 25.3-30.5%) ( p  < 0.001). Mean post-test score for computer-based picture speciation test (63.0%) and picture detection test (89.2%) were significantly higher than the mean post-test score for slide reading speciation test (38.3%) and slide reading detection test (70.7%), p  < 0.001 in both cases. Parasite detection and speciation using enhanced visual imaging was significantly improved compared with using direct microscopy. Regular in-service training and provision of functional and high resolution microscopes are needed to ensure quality routine malaria microscopy.

A Randomized Study Comparing Digital Imaging to Traditional Glass Slide Microscopy for Breast Biopsy and Cancer Diagnosis.

PubMed

Elmore, Joann G; Longton, Gary M; Pepe, Margaret S; Carney, Patricia A; Nelson, Heidi D; Allison, Kimberly H; Geller, Berta M; Onega, Tracy; Tosteson, Anna N A; Mercan, Ezgi; Shapiro, Linda G; Brunyé, Tad T; Morgan, Thomas R; Weaver, Donald L

2017-01-01

Digital whole slide imaging may be useful for obtaining second opinions and is used in many countries. However, the U.S. Food and Drug Administration requires verification studies. Pathologists were randomized to interpret one of four sets of breast biopsy cases during two phases, separated by ≥9 months, using glass slides or digital format (sixty cases per set, one slide per case, n = 240 cases). Accuracy was assessed by comparing interpretations to a consensus reference standard. Intraobserver reproducibility was assessed by comparing the agreement of interpretations on the same cases between two phases. Estimated probabilities of confirmation by a reference panel (i.e., predictive values) were obtained by incorporating data on the population prevalence of diagnoses. Sixty-five percent of responding pathologists were eligible, and 252 consented to randomization; 208 completed Phase I (115 glass, 93 digital); and 172 completed Phase II (86 glass, 86 digital). Accuracy was slightly higher using glass compared to digital format and varied by category: invasive carcinoma, 96% versus 93% ( P = 0.04); ductal carcinoma in situ (DCIS), 84% versus 79% ( P < 0.01); atypia, 48% versus 43% ( P = 0.08); and benign without atypia, 87% versus 82% ( P < 0.01). There was a small decrease in intraobserver agreement when the format changed compared to when glass slides were used in both phases ( P = 0.08). Predictive values for confirmation by a reference panel using glass versus digital were: invasive carcinoma, 98% and 97% (not significant [NS]); DCIS, 70% and 57% ( P = 0.007); atypia, 38% and 28% ( P = 0.002); and benign without atypia, 97% and 96% (NS). In this large randomized study, digital format interpretations were similar to glass slide interpretations of benign and invasive cancer cases. However, cases in the middle of the spectrum, where more inherent variability exists, may be more problematic in digital format. Future studies evaluating the effect these findings exert on clinical practice and patient outcomes are required.

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...

Summaries of "You Do It" Activities Presented at the 1978 SASTA Conference in the Riverland.

ERIC Educational Resources Information Center

Walsh, Terry

1980-01-01

Summarizes "you do it" activities presented at the 1978 South Australian Science Teachers Association Conference. Topics include microscope use and maintenance, chemical slide cells, chemical models, sound waves, microwaves, astronomy, plant keys, reading geological maps, and natural dye processes. (DS)

Counting Tree Growth Rings Moderately Difficult to Distinguish

Treesearch

C. B. Briscoe; M. Chudnoff

1964-01-01

There is an extensive literature dealing with techniques and gadgets to facilitate counting tree growth rings. A relatively simple method is described below, satisfactory for species too difficult to count in the field, but not sufficiently difficult to require the preparation of microscope slides nor staining techniques.

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.

Polypoid nodular histiocytic hyperplasia associated with endometrioid adenocarcinoma of the endometrium: report of a case

PubMed Central

2014-01-01

A 45 year old woman underwent Laparoscopy-assisted total hysterectomy with staging procedure following a diagnosis of endometrial endometrioid adenocarcinoma on her endometrial biopsy. The hysterectomy specimen showed a FIGO I stage 1a, endometrioid carcinoma. A separate polypoid lesion in the endometrium, distinct from the carcinoma, was also identified. Microscopically the polypoid lesion was “nodular histiocytic hyperplasia”. The H&E, immunohistochemical staining findings and the differential diagnoses are discussed in this report. Although description of similar lesions is available in the literature, the current lesion is unique as it is identified in a hysterectomy specimen in its entirety and its association with an endometrial endometrioid carcinoma. Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1060511915121922 PMID:24885845

Experimentally determined wear behavior of an Al2O3-SiC composite from 25 to 1200 C

NASA Technical Reports Server (NTRS)

Dellacorte, Christopher; Farmer, Serene C.; Book, Patricia O.

1990-01-01

The sliding wear behavior of a self-mated alumina-silicon carbide whisker toughened composite was studied using optical, scanning electron (SEM) and transmission electron (TEM) microscopy. Because of its excellent strength and toughness properties this composite material is under consideration for use in heat engine applications for sliding contacts which operate at elevated temperatures. The composite's wear behavior and especially its wear mechanisms are not well understood. Pin-on-disk specimens were slid in air at 2.7 m/s sliding velocity, under a 26.5-N load, at temperatures 25 to 1200 C. Pin wear increased with increasing temperature. Based upon the microscopic analyses, the wear mechanism seems to be loosening of the reinforcing whiskers due to frictional and bulk heating. This leads to whisker pullout and increased wear.

Note: A rigid piezo motor with large output force and an effective method to reduce sliding friction force.

PubMed

Guo, Ying; Hou, Yubin; Lu, Qingyou

2014-05-01

We present a completely practical TunaDrive piezo motor. It consists of a central piezo stack sandwiched by two arm piezo stacks and two leg piezo stacks, respectively, which is then sandwiched and spring-clamped by a pair of parallel polished sapphire rods. It works by alternatively fast expanding and contracting the arm/leg stacks while slowly expanding/contracting the central stack simultaneously. The key point is that sufficiently fast expanding and contracting a limb stack can make its two sliding friction forces well cancel, resulting in the total sliding friction force is <10% of the total static friction force, which can help increase output force greatly. The piezo motor's high compactness, precision, and output force make it perfect in building a high-quality harsh-condition (vibration resistant) atomic resolution scanning probe microscope.

Dry sliding wear system response of ferritic and tempered martensitic ductile iron

NASA Astrophysics Data System (ADS)

Jha, V. K.; Mozumder, Y. H.; Shama, S.; Behera, R. K.; Pattaniak, A.; P, Sindhoora L.; Mishra, S. C.; Sen, S.

2015-02-01

Spheroidal graphite cast iron (SG iron) is the most preferable member of cast iron family due to its strength and toughness along with good tribological properties. SG iron specimens with annealed and martensitic matrix were subjected to dry sliding wear condition and the system response was correlated to matrix microstructure. Respective microstructure was obtained by annealing and quench and tempering heat treatment process for an austenitizing temperature of 1000°C. Specimens were subjected to Ball on plate wear tester under 40N, 50N, 60N load for a sliding distance of 7.54m. Except for quench and tempered specimen at 50N, weight loss was observed in every condition. The wear surface under optical microscope reveals adhesive mechanism for as-cast and annealed specimen whereas delaminated wear track feature was observed for quench and tempered specimen.

Detection and Resolution of Cryptosporidium Species and Species Mixtures by Genus-Specific Nested PCR-Restriction Fragment Length Polymorphism Analysis, Direct Sequencing, and Cloning ▿

PubMed Central

Ruecker, Norma J.; Hoffman, Rebecca M.; Chalmers, Rachel M.; Neumann, Norman F.

2011-01-01

Molecular methods incorporating nested PCR-restriction fragment length polymorphism (RFLP) analysis of the 18S rRNA gene of Cryptosporidium species were validated to assess performance based on limit of detection (LoD) and for detecting and resolving mixtures of species and genotypes within a single sample. The 95% LoD was determined for seven species (Cryptosporidium hominis, C. parvum, C. felis, C. meleagridis, C. ubiquitum, C. muris, and C. andersoni) and ranged from 7 to 11 plasmid template copies with overlapping 95% confidence limits. The LoD values for genomic DNA from oocysts on microscope slides were 7 and 10 template copies for C. andersoni and C. parvum, respectively. The repetitive nested PCR-RFLP slide protocol had an LoD of 4 oocysts per slide. When templates of two species were mixed in equal ratios in the nested PCR-RFLP reaction mixture, there was no amplification bias toward one species over another. At high ratios of template mixtures (>1:10), there was a reduction or loss of detection of the less abundant species by RFLP analysis, most likely due to heteroduplex formation in the later cycles of the PCR. Replicate nested PCR was successful at resolving many mixtures of Cryptosporidium at template concentrations near or below the LoD. The cloning of nested PCR products resulted in 17% of the cloned sequences being recombinants of the two original templates. Limiting-dilution nested PCR followed by the sequencing of PCR products resulted in no sequence anomalies, suggesting that this method is an effective and accurate way to study the species diversity of Cryptosporidium, particularly for environmental water samples, in which mixtures of parasites are common. PMID:21498746

Preparation, Microstructure and Performance of Nanoscale Ceramics Reinforced Hard Composite Coating

NASA Astrophysics Data System (ADS)

Li, Peng

2014-11-01

This paper is based on the dry sliding wear of Stellite SF12-B4C-TiN-Mo composite coating deposited on a pure Ti using a laser cladding technique, the parameters of which provide almost crack-free composites with low porosity. To the best of our knowledge, it is the first time that Stellite SF12-B4C-TiN-Mo mixed powders are deposited as the hard composites by a laser cladding technique. Scanning electron microscope images indicate that the nanoscale particles are produced in such coating. The fact that due to the sufficiently rapid heating and cooling rates of the laser cladding technique, the ceramics, such as TiC or TiB2 did not have enough time to grow up, resulting in the formation of the nanoscale particles. Compared with a pure Ti substrate, the increments of the micro-hardness and wear resistance are obtained for such composite coating.

Survey: interpolation methods for whole slide image processing.

PubMed

Roszkowiak, L; Korzynska, A; Zak, J; Pijanowska, D; Swiderska-Chadaj, Z; Markiewicz, T

2017-02-01

Evaluating whole slide images of histological and cytological samples is used in pathology for diagnostics, grading and prognosis . It is often necessary to rescale whole slide images of a very large size. Image resizing is one of the most common applications of interpolation. We collect the advantages and drawbacks of nine interpolation methods, and as a result of our analysis, we try to select one interpolation method as the preferred solution. To compare the performance of interpolation methods, test images were scaled and then rescaled to the original size using the same algorithm. The modified image was compared to the original image in various aspects. The time needed for calculations and results of quantification performance on modified images were also compared. For evaluation purposes, we used four general test images and 12 specialized biological immunohistochemically stained tissue sample images. The purpose of this survey is to determine which method of interpolation is the best to resize whole slide images, so they can be further processed using quantification methods. As a result, the interpolation method has to be selected depending on the task involving whole slide images. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

[THE VIRTUAL CYTOLOGIC SLIDES FOR EXTERNAL EVALUATION OF QUALITY OF IMPLEMENTATION OF CYTOLOGIC ANALYSES IN CLINICAL DIAGNOSTIC LABORATORIES: POSSIBILITIES AND PERSPECTIVES].

PubMed

Djangirova, T V; Shabalova, I P; Pronichev, A N; Polyakov, E V

2015-08-01

The article considers application of technology of analysis of cytological slides in external quality control of clinical diagnostic laboratories. The advantages of virtual slides are demonstrated against other applied technologies of external evaluation of quality i.e. slide plate and digital micro-photography. The conditions of formation of virtual slides for external evaluation of quality of clinical diagnostic laboratories. The technology of their application is described. The success of practical application of considered technology in the Federal system of external evaluation of quality is emphasized.

Web-Based Virtual Microscopy of Digitized Blood Slides for Malaria Diagnosis: An Effective Tool for Skills Assessment in Different Countries and Environments.

PubMed

Ahmed, Laura; Seal, Leonard H; Ainley, Carol; De la Salle, Barbara; Brereton, Michelle; Hyde, Keith; Burthem, John; Gilmore, William Samuel

2016-08-11

Morphological examination of blood films remains the reference standard for malaria diagnosis. Supporting the skills required to make an accurate morphological diagnosis is therefore essential. However, providing support across different countries and environments is a substantial challenge. This paper reports a scheme supplying digital slides of malaria-infected blood within an Internet-based virtual microscope environment to users with different access to training and computing facilities. The feasibility of the approach was established, allowing users to test, record, and compare their own performance with that of other users. From Giemsa stained thick and thin blood films, 56 large high-resolution digital slides were prepared, using high-quality image capture and 63x oil-immersion objective lens. The individual images were combined using the photomerge function of Adobe Photoshop and then adjusted to ensure resolution and reproduction of essential diagnostic features. Web delivery employed the Digital Slidebox platform allowing digital microscope viewing facilities and image annotation with data gathering from participants. Engagement was high with images viewed by 38 participants in five countries in a range of environments and a mean completion rate of 42/56 cases. The rate of parasite detection was 78% and accuracy of species identification was 53%, which was comparable with results of similar studies using glass slides. Data collection allowed users to compare performance with other users over time or for each individual case. Overall, these results demonstrate that users worldwide can effectively engage with the system in a range of environments, with the potential to enhance personal performance through education, external quality assessment, and personal professional development, especially in regions where educational resources are difficult to access.

Discovery of a 240 million year old nematode parasite egg in a cynodont coprolite sheds light on the early origin of pinworms in vertebrates.

PubMed

Hugot, Jean-Pierre; Gardner, Scott L; Borba, Victor; Araujo, Priscilla; Leles, Daniela; Stock Da-Rosa, Átila Augusto; Dutra, Juliana; Ferreira, Luiz Fernando; Araújo, Adauto

2014-11-13

We report the discovery of a nematode parasite egg (Nemata: Oxyurida) from a coprolite closely associated with the remains of several species of Cynodontia, dated to 240 million years old. This finding is particularly significant because this is the oldest record of an oxyurid nematode yet discovered, and because the cynodonts are considered a stem-group of the mammals. We extracted material from a fully mineralized coprolite by both scraping the surface, and removing fragments from its interior with clean dental instruments used a single time. A single drop of glycerol from a new vial was added as a clearing reagent. Each slide was sealed with wax and examined with an optical microscope at 100× to 400× magnification. From one coprolite, 550 slides were examined; from 275 of these slides, sediment was examined that was scraped from the surface of the coprolite, and from the other 275 slides, material was examined that was extracted from the interior of the coprolite. All microscopic structures encountered were photographed, measured, and identified when possible. From the coprolite examined, we discovered an egg representing a new species of pinworm that, based on the egg structure, clearly places it in the family Heteroxynematidae. Nematodes of the order Oxyurida have very constrained life-histories, occurring only in animals that are not strictly carnivorous and also ingest large amounts of plant material. This fact enabled us to determine which species of cynodont, from several collected at the site in Brazil, are most likely the depositors of the coprolite, and therefore were the putative host of the parasite.

New Technologies: Real-time Telepathology Systems-Novel Cost-effective Tools for Real-time Consultation and Data Sharing.

PubMed

Siegel, Gabriel; Regelman, Dan; Maronpot, Robert; Rosenstock, Moti; Nyska, Abraham

2017-12-01

Real-time telepathology for use in investigative and regulated preclinical toxicology studies is now feasible. Newly developed microscope-integrated telepathology systems enable geographically remote stakeholders to view the live histopathology slide as seen by the study pathologist within the microscope. Simultaneous online viewing and dialog between study pathologist and remote colleagues is an efficient and cost-effective means for consultation, pathology working groups, and peer review, facilitating good science and economic benefits by enabling more timely and informed clinical decisions.

A rapid method for concentrating sedimentary organic matter for vitrinite reflectance analysis.

USGS Publications Warehouse

Barker, C.E.

1982-01-01

The tecnique discussed in this paper utilizes crushing, high-speed blending, and ultrasonic treatment to mechanically disaggregate rock and release the sedimentary organic matter (OM) in a suitable heavy liquid. This new method can provide freeze-dried concentrated OM in approximately 8 to 24 hours (longer time is necessary for removing carbonate). Under optimal conditions, it is possible to concentrate the OM and prepare a hardened epoxy microscope slide in about 24 hours. Subsequent grinding, polishing, and drying allows microscopic examination of the organic concentrate the next day.-from Author

Non-iterative characterization of few-cycle laser pulses using flat-top gates.

PubMed

Selm, Romedi; Krauss, Günther; Leitenstorfer, Alfred; Zumbusch, Andreas

2012-03-12

We demonstrate a method for broadband laser pulse characterization based on a spectrally resolved cross-correlation with a narrowband flat-top gate pulse. Excellent phase-matching by collinear excitation in a microscope focus is exploited by degenerate four-wave mixing in a microscope slide. Direct group delay extraction of an octave spanning spectrum which is generated in a highly nonlinear fiber allows for spectral phase retrieval. The validity of the technique is supported by the comparison with an independent second-harmonic fringe-resolved autocorrelation measurement for an 11 fs laser pulse.

Artificial testing targets with controllable blur for adaptive optics microscopes

NASA Astrophysics Data System (ADS)

Hattori, Masayuki; Tamada, Yosuke; Murata, Takashi; Oya, Shin; Hasebe, Mitsuyasu; Hayano, Yutaka; Kamei, Yasuhiro

2017-08-01

This letter proposes a method of configuring a testing target to evaluate the performance of adaptive optics microscopes. In this method, a testing slide with fluorescent beads is used to simultaneously determine the point spread function and the field of view. The point spread function is reproduced to simulate actual biological samples by etching a microstructure on the cover glass. The fabrication process is simplified to facilitate an onsite preparation. The artificial tissue consists of solid materials and silicone oil and is stable for use in repetitive experiments.

World petroleum assessment 2000; compiled PowerPoint slides

USGS Publications Warehouse

Ahlbrandt, Thomas S.

2001-01-01

The slides in this compilation have been produced for a number of presentations on the World Petroleum Assessment 20000. Many of the figures are taken directly form the publication "U.S. Geological Survey World Petroleum Assessment 2000" - Description and Results: USGS Digital Data Series DDS-60, 2000. Some of the slides are modifications of figures from DDS-60, some are new descriptive slides, and a few are new slides. Several of the slides appear to be duplicates, but in fact are slight modifications for format or content from the same image. Forty-one people participated in this effort as part of the World Energy Assessment Team. The full list of contributors is given ion DDS-60. 

The identity of Calliphora bezzii Zumpt, 1956 (Diptera, Calliphoridae).

PubMed

Rognes, Knut

2016-09-26

The holotype male of a nominal species described from Italy, Calliphora bezzii Zumpt, 1956, including a microscope slide of its terminalia, was examined. The holotype is shown to belong to the Nearctic taxon Calliphora latifrons Hough, 1899. Thus, Calliphora bezzii is a junior synonym of C. latifrons, syn. nov.

A Physical Chemistry Experiment in Polymer Crystallization Kinetics

ERIC Educational Resources Information Center

Singfield, Kathy L.; Chisholm, Roderick A.; King, Thomas L.

2012-01-01

A laboratory experiment currently used in an undergraduate physical chemistry lab to investigate the rates of crystallization of a polymer is described. Specifically, the radial growth rates of typical disc-shaped crystals, called spherulites, growing between microscope glass slides are measured and the data are treated according to polymer…

Making One-Computer Teaching Fun!

ERIC Educational Resources Information Center

Tan, Soo Boo

1998-01-01

Most teachers face the challenge of bringing technology into classrooms with only one computer. This article describes how one computer can serve the needs of many students: connecting it to a TV or projection device to display agendas, Web sites, microscope slides and other scientific instruments, and spreadsheets; tabulate data; deliver…

A Simple Approach to the Study of Attached Micro-Algae.

ERIC Educational Resources Information Center

Bell, Derek; Bell, J. Wendy

1980-01-01

Describes a modification in the use of artificial substrates to study attached micro-algae. Apparatus is based on glass microscope slides immersed in natural water environments; biomass and primary productivity are assessed by measurement of alpha-chlorophyll. Describes use in studies of colonization, succession, and populational fluctuation. (CS)

Leaf Histology--Two Modern Methods.

ERIC Educational Resources Information Center

Freeman, H. E.

1984-01-01

Two methods for examining leaf structure are presented; both methods involve use of "superglue." The first method uses the glue to form a thin, permanent, direct replica of a leaf surface on a microscope slide. The second method uses the glue to examine the three-dimensional structure of spongy mesophyll. (JN)

Leader-follower formation control of underactuated surface vehicles based on sliding mode control and parameter estimation.

PubMed

Sun, Zhijian; Zhang, Guoqing; Lu, Yu; Zhang, Weidong

2018-01-01

This paper studies the leader-follower formation control of underactuated surface vehicles with model uncertainties and environmental disturbances. A parameter estimation and upper bound estimation based sliding mode control scheme is proposed to solve the problem of the unknown plant parameters and environmental disturbances. For each of these leader-follower formation systems, the dynamic equations of position and attitude are analyzed using coordinate transformation with the aid of the backstepping technique. All the variables are guaranteed to be uniformly ultimately bounded stable in the closed-loop system, which is proven by the distribution design Lyapunov function synthesis. The main advantages of this approach are that: first, parameter estimation based sliding mode control can enhance the robustness of the closed-loop system in presence of model uncertainties and environmental disturbances; second, a continuous function is developed to replace the signum function in the design of sliding mode scheme, which devotes to reduce the chattering of the control system. Finally, numerical simulations are given to demonstrate the effectiveness of the proposed method. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Comparison of glass slides and various digital-slide modalities for cytopathology screening and interpretation.

PubMed

Hanna, Matthew G; Monaco, Sara E; Cuda, Jacqueline; Xing, Juan; Ahmed, Ishtiaque; Pantanowitz, Liron

2017-09-01

Whole-slide imaging in cytology is limited when glass slides are digitized without z-stacks for focusing. Different vendors have started to provide z-stacking solutions to overcome this limitation. The Panoptiq imaging system allows users to create digital files combining low-magnification panoramic images with regions of interest (ROIs) that are imaged with high-magnification z-stacks. The aim of this study was to compare such panoramic images with conventional whole-slide images and glass slides for the tasks of screening and interpretation in cytopathology. Thirty glass slides, including 10 ThinPrep Papanicolaou tests and 20 nongynecologic cytology cases, were digitized with an Olympus BX45 integrated microscope with an attached Prosilica GT camera. ViewsIQ software was used for image acquisition and viewing. These glass slides were also scanned on an Aperio ScanScope XT at ×40 (0.25 μm/pixel) with 1 z-plane and were viewed with ImageScope software. Digital and glass sides were screened and dotted/annotated by a cytotechnologist and were subsequently reviewed by 3 cytopathologists. For panoramic images, the cytotechnologist manually created digital maps and selected representative ROIs to generate z-stacks at a higher magnification. After 3-week washout periods, panoramic images were compared with Aperio digital slides and glass slides. The Panoptiq system permitted fine focusing of thick smears and cell clusters. In comparison with glass slides, the average screening times were 5.5 and 1.8 times longer with Panoptiq and Aperio images, respectively, but this improved with user experience. There was no statistical difference in diagnostic concordance between all 3 modalities. Users' diagnostic confidence was also similar for all modalities. The Aperio whole-slide scanner with 1 z-plane scanning and the Panoptiq imaging system with z-stacking are both suitable for cytopathology screening and interpretation. However, ROI z-stacks do offer a superior mechanism for overcoming focusing problems commonly encountered with digital cytology slides. Unlike whole-slide imaging, the acquisition of representative z-stack images with the Panoptiq system requires a trained cytologist to create digital files. Cancer Cytopathol 2017;125:701-9. © 2017 American Cancer Society. © 2017 American Cancer Society.

Development of a Whole Slide Imaging System on Smartphones and Evaluation With Frozen Section Samples

PubMed Central

Jiang, Liren

2017-01-01

Background The aim was to develop scalable Whole Slide Imaging (sWSI), a WSI system based on mainstream smartphones coupled with regular optical microscopes. This ultra-low-cost solution should offer diagnostic-ready imaging quality on par with standalone scanners, supporting both oil and dry objective lenses of different magnifications, and reasonably high throughput. These performance metrics should be evaluated by expert pathologists and match those of high-end scanners. Objective The aim was to develop scalable Whole Slide Imaging (sWSI), a whole slide imaging system based on smartphones coupled with optical microscopes. This ultra-low-cost solution should offer diagnostic-ready imaging quality on par with standalone scanners, supporting both oil and dry object lens of different magnification. All performance metrics should be evaluated by expert pathologists and match those of high-end scanners. Methods In the sWSI design, the digitization process is split asynchronously between light-weight clients on smartphones and powerful cloud servers. The client apps automatically capture FoVs at up to 12-megapixel resolution and process them in real-time to track the operation of users, then give instant feedback of guidance. The servers first restitch each pair of FoVs, then automatically correct the unknown nonlinear distortion introduced by the lens of the smartphone on the fly, based on pair-wise stitching, before finally combining all FoVs into one gigapixel VS for each scan. These VSs can be viewed using Internet browsers anywhere. In the evaluation experiment, 100 frozen section slides from patients randomly selected among in-patients of the participating hospital were scanned by both a high-end Leica scanner and sWSI. All VSs were examined by senior pathologists whose diagnoses were compared against those made using optical microscopy as ground truth to evaluate the image quality. Results The sWSI system is developed for both Android and iPhone smartphones and is currently being offered to the public. The image quality is reliable and throughput is approximately 1 FoV per second, yielding a 15-by-15 mm slide under 20X object lens in approximately 30-35 minutes, with little training required for the operator. The expected cost for setup is approximately US $100 and scanning each slide costs between US $1 and $10, making sWSI highly cost-effective for infrequent or low-throughput usage. In the clinical evaluation of sample-wise diagnostic reliability, average accuracy scores achieved by sWSI-scan-based diagnoses were as follows: 0.78 for breast, 0.88 for uterine corpus, 0.68 for thyroid, and 0.50 for lung samples. The respective low-sensitivity rates were 0.05, 0.05, 0.13, and 0.25 while the respective low-specificity rates were 0.18, 0.08, 0.20, and 0.25. The participating pathologists agreed that the overall quality of sWSI was generally on par with that produced by high-end scanners, and did not affect diagnosis in most cases. Pathologists confirmed that sWSI is reliable enough for standard diagnoses of most tissue categories, while it can be used for quick screening of difficult cases. Conclusions As an ultra-low-cost alternative to whole slide scanners, diagnosis-ready VS quality and robustness for commercial usage is achieved in the sWSI solution. Operated on main-stream smartphones installed on normal optical microscopes, sWSI readily offers affordable and reliable WSI to resource-limited or infrequent clinical users. PMID:28916508

Segmentation of white blood cells and comparison of cell morphology by linear and naïve Bayes classifiers.

PubMed

Prinyakupt, Jaroonrut; Pluempitiwiriyawej, Charnchai

2015-06-30

Blood smear microscopic images are routinely investigated by haematologists to diagnose most blood diseases. However, the task is quite tedious and time consuming. An automatic detection and classification of white blood cells within such images can accelerate the process tremendously. In this paper we propose a system to locate white blood cells within microscopic blood smear images, segment them into nucleus and cytoplasm regions, extract suitable features and finally, classify them into five types: basophil, eosinophil, neutrophil, lymphocyte and monocyte. Two sets of blood smear images were used in this study's experiments. Dataset 1, collected from Rangsit University, were normal peripheral blood slides under light microscope with 100× magnification; 555 images with 601 white blood cells were captured by a Nikon DS-Fi2 high-definition color camera and saved in JPG format of size 960 × 1,280 pixels at 15 pixels per 1 μm resolution. In dataset 2, 477 cropped white blood cell images were downloaded from CellaVision.com. They are in JPG format of size 360 × 363 pixels. The resolution is estimated to be 10 pixels per 1 μm. The proposed system comprises a pre-processing step, nucleus segmentation, cell segmentation, feature extraction, feature selection and classification. The main concept of the segmentation algorithm employed uses white blood cell's morphological properties and the calibrated size of a real cell relative to image resolution. The segmentation process combined thresholding, morphological operation and ellipse curve fitting. Consequently, several features were extracted from the segmented nucleus and cytoplasm regions. Prominent features were then chosen by a greedy search algorithm called sequential forward selection. Finally, with a set of selected prominent features, both linear and naïve Bayes classifiers were applied for performance comparison. This system was tested on normal peripheral blood smear slide images from two datasets. Two sets of comparison were performed: segmentation and classification. The automatically segmented results were compared to the ones obtained manually by a haematologist. It was found that the proposed method is consistent and coherent in both datasets, with dice similarity of 98.9 and 91.6% for average segmented nucleus and cell regions, respectively. Furthermore, the overall correction rate in the classification phase is about 98 and 94% for linear and naïve Bayes models, respectively. The proposed system, based on normal white blood cell morphology and its characteristics, was applied to two different datasets. The results of the calibrated segmentation process on both datasets are fast, robust, efficient and coherent. Meanwhile, the classification of normal white blood cells into five types shows high sensitivity in both linear and naïve Bayes models, with slightly better results in the linear classifier.

Analyzing huge pathology images with open source software

PubMed Central

2013-01-01

Background Digital pathology images are increasingly used both for diagnosis and research, because slide scanners are nowadays broadly available and because the quantitative study of these images yields new insights in systems biology. However, such virtual slides build up a technical challenge since the images occupy often several gigabytes and cannot be fully opened in a computer’s memory. Moreover, there is no standard format. Therefore, most common open source tools such as ImageJ fail at treating them, and the others require expensive hardware while still being prohibitively slow. Results We have developed several cross-platform open source software tools to overcome these limitations. The NDPITools provide a way to transform microscopy images initially in the loosely supported NDPI format into one or several standard TIFF files, and to create mosaics (division of huge images into small ones, with or without overlap) in various TIFF and JPEG formats. They can be driven through ImageJ plugins. The LargeTIFFTools achieve similar functionality for huge TIFF images which do not fit into RAM. We test the performance of these tools on several digital slides and compare them, when applicable, to standard software. A statistical study of the cells in a tissue sample from an oligodendroglioma was performed on an average laptop computer to demonstrate the efficiency of the tools. Conclusions Our open source software enables dealing with huge images with standard software on average computers. They are cross-platform, independent of proprietary libraries and very modular, allowing them to be used in other open source projects. They have excellent performance in terms of execution speed and RAM requirements. They open promising perspectives both to the clinician who wants to study a single slide and to the research team or data centre who do image analysis of many slides on a computer cluster. Virtual slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5955513929846272 PMID:23829479

Superhydrophilic nanopillar-structured quartz surfaces for the prevention of biofilm formation in optical devices

NASA Astrophysics Data System (ADS)

Han, Soo; Ji, Seungmuk; Abdullah, Abdullah; Kim, Duckil; Lim, Hyuneui; Lee, Donghyun

2018-01-01

Bacterial biofilm formation on optical devices such as contact lenses, optical glasses, endoscopic devices, and microscopic slides and lenses are major concerns in the field of medicine and biomedical engineering. To solve these problems, here we present the first report of superhydrophilic transparent nanopillar-structured surfaces with bactericidal properties. To construct bactericidal surfaces, we imitated a topological mechanism found in nature in which nanopillar-structured surfaces cause a mechanical disruption of the outer cell membranes of bacteria, resulting in bacterial cell death. We used nanosphere lithography to fabricate nanopillars with various sharpnesses and heights on a quartz substrate. Water contact angle and light reflectance measurements revealed superhydrophilic, antifogging and antireflective properties, which are important for use in optical devices. To determine bactericidal efficiency, the fabricated surfaces were incubated and tested against two Gram-negative bacteria associated with biofilm formation and various diseases in humans, Pseudomonas aeruginosa and Escherichia coli. The highest bactericidal activity was achieved with nanopillars that measured 300 nm in height and 10 nm in apex diameter. Quartz substrates patterned with such nanopillars killed ∼38,000 P. aeruginosa and ∼27,000 E. coli cells cm-2 min-1, respectively. Thus, the newly designed nanopillar-structured bactericidal surfaces are suitable for use in the development of superhydrophilic and transparent optical devices.

Electrical Field Guided Electrospray Deposition for Production of Gradient Particle Patterns.

PubMed

Yan, Wei-Cheng; Xie, Jingwei; Wang, Chi-Hwa

2018-06-06

Our previous work demonstrated the uniform particle pattern formation on the substrates using electrical field guided electrospray deposition. In this work, we reported for the first time the fabrication of gradient particle patterns on glass slides using an additional point, line, or bar electrode based on our previous electrospray deposition configuration. We also demonstrated that the polydimethylsiloxane (PDMS) coating could result in the formation of uniform particle patterns instead of gradient particle patterns on glass slides using the same experimental setup. Meanwhile, we investigated the effect of experimental configurations on the gradient particle pattern formation by computational simulation. The simulation results are in line with experimental observations. The formation of gradient particle patterns was ascribed to the gradient of electric field and the corresponding focusing effect. Cell patterns can be formed on the particle patterns deposited on PDMS-coated glass slides. The formed particle patterns hold great promise for high-throughput screening of biomaterial-cell interactions and sensing.

Scanning electron microscope study of polytetrafluoroethylene sliding on aluminum single crystals

NASA Technical Reports Server (NTRS)

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

1973-01-01

Friction experiments were conducted in air with polytetrafluoroethylene (PTFE) sliding on aluminum single crystals. Mechanical scoring of the crystals with (110) and (100) orientations was observed with a single pass of the PTFE slider. No scoring was observed on the (111). The degree of scoring of the crystals is related to the hardness, with the hardest surface (111) showing no damage and the softest surface (110) showing the most severe scoring. Scoring is caused by work-hardened pieces of aluminum which, as a consequence of the adhesion between PTFE and aluminum, were pulled out of the bulk and became embedded in the PTFE polymer.

Does the 'old bag' make a good 'wind bag'?: Comparison of four fabrics commonly used as exclusion bags in studies of pollination and reproductive biology.

PubMed

Neal, Paul R; Anderson, Gregory J

2004-05-01

Fabrics used in pollination bags may exclude pollen carried by biotic vectors, but have varying degrees of permeability to wind-borne pollen. The permeability of bags to wind-borne pollen may have important consequences in studies of pollination and reproductive biology. The permeability of four fabrics commonly used in the construction of pollination bags was examined. Deposition of wind-borne pollen on horizontally and vertically oriented microscope slides was assessed on slides enclosed in pollination bags, as well as on control slides. It was found that the permeability of fabrics to wind-borne pollen, as measured by deposition on both horizontally and vertically oriented slides, decreased with pore size. However, deposition on horizontal slides was always greater than on vertical slides for a given fabric; this could manifest itself as differential success of pollination of flowers in bags-dependent on flower orientation. Obviously, bags with mesh size smaller than most pollen grains are impermeable to pollen. However, material for such bags is very expensive. In addition, it was also observed that bags with even moderately small pore size, such as pores (approx. 200 microm) in twisted fibre cotton muslin, offered highly significant barriers to passage of wind-borne pollen. Such bags are sufficiently effective in most large-sample-size reproductive biology studies.

Wide-field computational imaging of pathology slides using lens-free on-chip microscopy.

PubMed

Greenbaum, Alon; Zhang, Yibo; Feizi, Alborz; Chung, Ping-Luen; Luo, Wei; Kandukuri, Shivani R; Ozcan, Aydogan

2014-12-17

Optical examination of microscale features in pathology slides is one of the gold standards to diagnose disease. However, the use of conventional light microscopes is partially limited owing to their relatively high cost, bulkiness of lens-based optics, small field of view (FOV), and requirements for lateral scanning and three-dimensional (3D) focus adjustment. We illustrate the performance of a computational lens-free, holographic on-chip microscope that uses the transport-of-intensity equation, multi-height iterative phase retrieval, and rotational field transformations to perform wide-FOV imaging of pathology samples with comparable image quality to a traditional transmission lens-based microscope. The holographically reconstructed image can be digitally focused at any depth within the object FOV (after image capture) without the need for mechanical focus adjustment and is also digitally corrected for artifacts arising from uncontrolled tilting and height variations between the sample and sensor planes. Using this lens-free on-chip microscope, we successfully imaged invasive carcinoma cells within human breast sections, Papanicolaou smears revealing a high-grade squamous intraepithelial lesion, and sickle cell anemia blood smears over a FOV of 20.5 mm(2). The resulting wide-field lens-free images had sufficient image resolution and contrast for clinical evaluation, as demonstrated by a pathologist's blinded diagnosis of breast cancer tissue samples, achieving an overall accuracy of ~99%. By providing high-resolution images of large-area pathology samples with 3D digital focus adjustment, lens-free on-chip microscopy can be useful in resource-limited and point-of-care settings. Copyright © 2014, American Association for the Advancement of Science.

Breast cancer histopathology image analysis: a review.

PubMed

Veta, Mitko; Pluim, Josien P W; van Diest, Paul J; Viergever, Max A

2014-05-01

This paper presents an overview of methods that have been proposed for the analysis of breast cancer histopathology images. This research area has become particularly relevant with the advent of whole slide imaging (WSI) scanners, which can perform cost-effective and high-throughput histopathology slide digitization, and which aim at replacing the optical microscope as the primary tool used by pathologist. Breast cancer is the most prevalent form of cancers among women, and image analysis methods that target this disease have a huge potential to reduce the workload in a typical pathology lab and to improve the quality of the interpretation. This paper is meant as an introduction for nonexperts. It starts with an overview of the tissue preparation, staining and slide digitization processes followed by a discussion of the different image processing techniques and applications, ranging from analysis of tissue staining to computer-aided diagnosis, and prognosis of breast cancer patients.

Peak effect versus skating in high-temperature nanofriction

NASA Astrophysics Data System (ADS)

Zykova-Timan, T.; Ceresoli, D.; Tosatti, E.

2007-03-01

The physics of sliding nanofriction at high temperature near the substrate melting point, TM, is so far unexplored. We conducted simulations of hard tips sliding on a prototype non-melting surface, NaCl(100), revealing two distinct and opposite phenomena for ploughing and for grazing friction in this regime. We found a frictional drop close to TM for deep ploughing and wear, but on the contrary a frictional rise for grazing, wearless sliding. For both phenomena, we obtain a fresh microscopic understanding, relating the former to `skating' through a local liquid cloud, and the latter to linear response properties of the free substrate surface. We argue that both phenomena occur more generally on surfaces other than NaCl and should be pursued experimentally. Most metals, in particular those possessing one or more close-packed non-melting surfaces, such as Pb, Al or Au(111), are likely to behave similarly.

Optimized graph-based mosaicking for virtual microscopy

NASA Astrophysics Data System (ADS)

Steckhan, Dirk G.; Wittenberg, Thomas

2009-02-01

Virtual microscopy has the potential to partially replace traditional microscopy. For virtualization, the slide is scanned once by a fully automatized robotic microscope and saved digitally. Typically, such a scan results in several hundreds to thousands of fields of view. Since robotic stages have positioning errors, these fields of view have to be registered locally and globally in an additional step. In this work we propose a new global mosaicking method for the creation of virtual slides based on sub-pixel exact phase correlation for local alignment in combination with Prim's minimum spanning tree algorithm for global alignment. Our algorithm allows for a robust reproduction of the original slide even in the presence of views with little to no information content. This makes it especially suitable for the mosaicking of cervical smears. These smears often exhibit large empty areas, which do not contain enough information for common stitching approaches.

Note: A rigid piezo motor with large output force and an effective method to reduce sliding friction force

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

Guo, Ying; Lu, Qingyou, E-mail: qxl@ustc.edu.cn; Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026

2014-05-15

We present a completely practical TunaDrive piezo motor. It consists of a central piezo stack sandwiched by two arm piezo stacks and two leg piezo stacks, respectively, which is then sandwiched and spring-clamped by a pair of parallel polished sapphire rods. It works by alternatively fast expanding and contracting the arm/leg stacks while slowly expanding/contracting the central stack simultaneously. The key point is that sufficiently fast expanding and contracting a limb stack can make its two sliding friction forces well cancel, resulting in the total sliding friction force is <10% of the total static friction force, which can help increasemore » output force greatly. The piezo motor's high compactness, precision, and output force make it perfect in building a high-quality harsh-condition (vibration resistant) atomic resolution scanning probe microscope.« less

Proposals for best-quality immunohistochemical staining of paraffin-embedded brain tissue slides in forensics.

PubMed

Trautz, Florian; Dreßler, Jan; Stassart, Ruth; Müller, Wolf; Ondruschka, Benjamin

2018-01-03

Immunohistochemistry (IHC) has become an integral part in forensic histopathology over the last decades. However, the underlying methods for IHC vary greatly depending on the institution, creating a lack of comparability. The aim of this study was to assess the optimal approach for different technical aspects of IHC, in order to improve and standardize this procedure. Therefore, qualitative results from manual and automatic IHC staining of brain samples were compared, as well as potential differences in suitability of common IHC glass slides. Further, possibilities of image digitalization and connected issues were investigated. In our study, automatic staining showed more consistent staining results, compared to manual staining procedures. Digitalization and digital post-processing facilitated direct analysis and analysis for reproducibility considerably. No differences were found for different commercially available microscopic glass slides regarding suitability of IHC brain researches, but a certain rate of tissue loss should be expected during the staining process.

Computer-assisted image processing to detect spores from the fungus Pandora neoaphidis.

PubMed

Korsnes, Reinert; Westrum, Karin; Fløistad, Erling; Klingen, Ingeborg

2016-01-01

This contribution demonstrates an example of experimental automatic image analysis to detect spores prepared on microscope slides derived from trapping. The application is to monitor aerial spore counts of the entomopathogenic fungus Pandora neoaphidis which may serve as a biological control agent for aphids. Automatic detection of such spores can therefore play a role in plant protection. The present approach for such detection is a modification of traditional manual microscopy of prepared slides, where autonomous image recording precedes computerised image analysis. The purpose of the present image analysis is to support human visual inspection of imagery data - not to replace it. The workflow has three components:•Preparation of slides for microscopy.•Image recording.•Computerised image processing where the initial part is, as usual, segmentation depending on the actual data product. Then comes identification of blobs, calculation of principal axes of blobs, symmetry operations and projection on a three parameter egg shape space.

Imaging high-speed friction at the nanometer scale

PubMed Central

Thorén, Per-Anders; de Wijn, Astrid S.; Borgani, Riccardo; Forchheimer, Daniel; Haviland, David B.

2016-01-01

Friction is a complicated phenomenon involving nonlinear dynamics at different length and time scales. Understanding its microscopic origin requires methods for measuring force on nanometer-scale asperities sliding at velocities reaching centimetres per second. Despite enormous advances in experimental technique, this combination of small length scale and high velocity remain elusive. We present a technique for rapidly measuring the frictional forces on a single asperity over a velocity range from zero to several centimetres per second. At each image pixel we obtain the velocity dependence of both conservative and dissipative forces, revealing the transition from stick-slip to smooth sliding friction. We explain measurements on graphite using a modified Prandtl–Tomlinson model, including the damped elastic deformation of the asperity. With its improved force sensitivity and small sliding amplitude, our method enables rapid and detailed surface mapping of the velocity dependence of frictional forces with less than 10 nm spatial resolution. PMID:27958267

An entirely automated method to score DSS-induced colitis in mice by digital image analysis of pathology slides

PubMed Central

Kozlowski, Cleopatra; Jeet, Surinder; Beyer, Joseph; Guerrero, Steve; Lesch, Justin; Wang, Xiaoting; DeVoss, Jason; Diehl, Lauri

2013-01-01

SUMMARY The DSS (dextran sulfate sodium) model of colitis is a mouse model of inflammatory bowel disease. Microscopic symptoms include loss of crypt cells from the gut lining and infiltration of inflammatory cells into the colon. An experienced pathologist requires several hours per study to score histological changes in selected regions of the mouse gut. In order to increase the efficiency of scoring, Definiens Developer software was used to devise an entirely automated method to quantify histological changes in the whole H&E slide. When the algorithm was applied to slides from historical drug-discovery studies, automated scores classified 88% of drug candidates in the same way as pathologists’ scores. In addition, another automated image analysis method was developed to quantify colon-infiltrating macrophages, neutrophils, B cells and T cells in immunohistochemical stains of serial sections of the H&E slides. The timing of neutrophil and macrophage infiltration had the highest correlation to pathological changes, whereas T and B cell infiltration occurred later. Thus, automated image analysis enables quantitative comparisons between tissue morphology changes and cell-infiltration dynamics. PMID:23580198

Issues in using whole slide imaging for diagnostic pathology: "routine" stains, immunohistochemistry and predictive markers.

PubMed

Taylor, C R

2014-08-01

The traditional microscope, together with the "routine" hematoxylin and eosin (H & E) stain, remains the "gold standard" for diagnosis of cancer and other diseases; remarkably, it and the majority of associated biological stains are more than 150 years old. Immunohistochemistry has added to the repertoire of "stains" available. Because of the need for specific identification and even measurement of "biomarkers," immunohistochemistry has increased the demand for consistency of performance and interpretation of staining results. Rapid advances in the capabilities of digital imaging hardware and software now offer a realistic route to improved reproducibility, accuracy and quantification by utilizing whole slide digital images for diagnosis, education and research. There also are potential efficiencies in work flow and the promise of powerful new analytical methods; however, there also are challenges with respect to validation of the quality and fidelity of digital images, including the standard H & E stain, so that diagnostic performance by pathologists is not compromised when they rely on whole slide images instead of traditional stained tissues on glass slides.

Numerical analysis of micro-/nanoscale gas-film lubrication of sliding surface with complicated structure

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

Kawagoe, Yoshiaki; Isono, Susumu; Takeno, Takanori

2014-12-09

It has been reported that the friction between a partially polished diamond-coated surface and a metal surface was drastically reduced to zero when they are slid at a few m/s. Since the sliding was noiseless, it seems that the diamond-coated surface was levitated over the counter surface and the sliding mechanism was the gas film lubrication. Recently, the mechanism of levitation of a slider with a micro/nanoscale surface structure on a rotating disk was theoretically clarified [S. Yonemura et al., Tribol. Lett., (2014), doi:10.1007/s11249-014-0368-2]. Probably, the partially polished diamond-coated surface may be levitated by high gas pressure generated by themore » micro/nanoscale surface structure on it. In this study, in order to verify our deduction, we performed numerical simulations of sliding of partially polished diamond-coated surface by reproducing its complicated surface structure using the data measured by an atomic force microscope (AFM). As a result, we obtained the lift force which is large enough to levitate the slider used in the experiment.« less

An Efficient Computational Framework for the Analysis of Whole Slide Images: Application to Follicular Lymphoma Immunohistochemistry

PubMed Central

Samsi, Siddharth; Krishnamurthy, Ashok K.; Gurcan, Metin N.

2012-01-01

Follicular Lymphoma (FL) is one of the most common non-Hodgkin Lymphoma in the United States. Diagnosis and grading of FL is based on the review of histopathological tissue sections under a microscope and is influenced by human factors such as fatigue and reader bias. Computer-aided image analysis tools can help improve the accuracy of diagnosis and grading and act as another tool at the pathologist’s disposal. Our group has been developing algorithms for identifying follicles in immunohistochemical images. These algorithms have been tested and validated on small images extracted from whole slide images. However, the use of these algorithms for analyzing the entire whole slide image requires significant changes to the processing methodology since the images are relatively large (on the order of 100k × 100k pixels). In this paper we discuss the challenges involved in analyzing whole slide images and propose potential computational methodologies for addressing these challenges. We discuss the use of parallel computing tools on commodity clusters and compare performance of the serial and parallel implementations of our approach. PMID:22962572

Biofilms inducing ultra-low friction on titanium.

PubMed

Souza, J C M; Henriques, M; Oliveira, R; Teughels, W; Celis, J-P; Rocha, L A

2010-12-01

Biofilm formation is widely reported in the literature as a problem in the healthcare, environmental, and industrial sectors. However, the role of biofilms in sliding contacts remains unclear. Friction during sliding was analyzed for titanium covered with mixed biofilms consisting of Streptococcus mutans and Candida albicans. The morphology of biofilms on titanium surfaces was evaluated before, during, and after sliding tests. Very low friction was recorded on titanium immersed in artificial saliva and sliding against alumina in the presence of biofilms. The complex structure of biofilms, which consist of microbial cells and their hydrated exopolymeric matrix, acts like a lubricant. A low friction in sliding contacts may have major significance in the medical field. The composition and structure of biofilms are shown to be key factors for an understanding of friction behavior of dental implant connections and prosthetic joints. For instance, a loss of mechanical integrity of dental implant internal connections may occur as a consequence of the decrease in friction caused by biofilm formation. Consequently, the study of the exopolymeric matrix can be important for the development of high-performance novel joint-based systems for medical and other engineering applications.

Investigation of Bearing Axial Cracking: Benchtop and Full-Scale Test Results

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

Keller, Jonathan A.; Gould, Benjamin; Greco, Aaron

2017-08-16

The most common failure mode in wind turbine gearboxes is axial cracking in intermediate and high-speed-stage bearings, also commonly called white-etching cracks (WECs). Although these types of cracks have been reported for over a decade, the conditions leading to WECs, the process by which this failure culminates, and the reasons for their apparent prevalence in wind turbine gearboxes are all highly debated. This paper summarizes the state of a multipronged research effort to examine the causes of WECs in wind turbine gearbox bearings. Recent efforts have recreated WECs on a benchtop test rig in highly loaded sliding conditions, wherein itmore » was found that the formation of a dark etching microstructure precedes the formation of a crack, and a crack precedes the formation of white-etching microstructure. A cumulative frictional sliding energy criterion has been postulated to predict the presence of WECs. Bearing loads have also been measured and predicted in steady state and transient drivetrain operations in dynamometer testing. In addition, both loads and sliding at full scale will be measured in planned uptower drivetrain testing. If the cumulative frictional sliding energy is the dominant mechanism that causes WECs, understanding the amount of frictional sliding energy that wind turbine bearings are subjected to in typical operations is the next step in the investigation. If highly loaded sliding conditions are found uptower, similar to the examined benchtop levels, appropriate mitigation solutions can be examined, ranging from new bearing coatings and improved lubricants to changes in gearbox designs and turbine operations.« less

A Comparison of Heat versus Methanol Fixation for Gram Staining Bacteria

ERIC Educational Resources Information Center

Minnerath, Jeanne M.; Roland, Jenna M.; Rossi, Lucas C.; Weishalla, Steven R.; Wolf, Melissa M.

2009-01-01

Gram staining bacteria is a fundamental technique introduced in general biology and microbiology laboratory courses. Two common problems students encounter when Gram staining bacteria are (1) having a difficult time locating bacterial cells on the microscope slide and (2) over-decolorizing bacterial cells during the staining procedure such that…

A Method of Recording and Predicting the Pollen Count.

ERIC Educational Resources Information Center

Buck, M.

1985-01-01

A hair dryer, plastic funnel, and microscope slide can be used for predicting pollen counts on a day-to-day basis. Materials, methods for assembly, collection technique, meteorological influences, and daily patterns are discussed. Data collected using the apparatus suggest that airborne grass products other than pollen also affect hay fever…

Kaleidoscopes Made with Big Mirrors

ERIC Educational Resources Information Center

Greenslade, Thomas B., Jr.

2009-01-01

The familiar kaleidoscope toy was developed by the Scottish physicist David Brewster (1781-1868) in 1816, patented by him in 1817, and described in his 1819 book, "A Treatise on the Kaleidoscope." Generations of elementary students have made their own kaleidoscopes by assembling three microscope slides inside a tube and looking through it at a…

Raman mapping of intact biofilms on stainless steel surfaces

USDA-ARS?s Scientific Manuscript database

Each slide under the Raman Microscope was mapped for approximately 18.5 hours with a dimension of 36x36 that provides a greater result compared to doing a smaller dimension scan. The results from the Raman Mapping show the location and position of how the bacteria are growing scattered or straight a...

Electronic Blending in Virtual Microscopy

ERIC Educational Resources Information Center

Maybury, Terrence S.; Farah, Camile S.

2010-01-01

Virtual microscopy (VM) is a relatively new technology that transforms the computer into a microscope. In essence, VM allows for the scanning and transfer of glass slides from light microscopy technology to the digital environment of the computer. This transition is also a function of the change from print knowledge to electronic knowledge, or as…

Effect of heat input on microstructure, wear and friction behavior of (wt.-%) 50FeCrC-20FeW-30FeB coating on AISI 1020 produced by using PTA welding.

PubMed

Özel, Cihan; Gürgenç, Turan

2018-01-01

In this study, AISI 1020 steel surface was coated in different heat inputs with (wt.-%) 50FeCrC-20FeW-30FeB powder mixture by using plasma transferred arc (PTA) welding method. The microstructure of the coated samples were investigated by using optical microscope (OM), scanning electron microscope (SEM), X-ray diffraction (XRD) and energy dispersive X-ray (EDS). The hardness was measured with micro hardness test device. The dry sliding wear and friction coefficient properties were determined using a block-on-disk type wear test device. Wear tests were performed at 19.62 N, 39.24 N, 58.86 N load and the sliding distance of 900 m. The results were shown that different microstructures formed due to the heat input change. The highest average micro hardness value was measured at 1217 HV on sample coated with low heat input. It was determined that the wear resistance decreased with increasing heat input.

Evaluation of sperm motility with CASA-Mot: which factors may influence our measurements?

PubMed

Yeste, Marc; Bonet, Sergi; Rodríguez-Gil, Joan E; Rivera Del Álamo, Maria M

2018-03-14

Computer-aided sperm analysis (CASA) is now routinely used in IVF clinics, animal breeding centres and research laboratories. Although CASA provides a more objective way to evaluate sperm parameters, a significant number of factors can affect these measurements. This paper classifies these factors into four categories: (1) sample and slide (e.g. preincubation time, type of specimen and type of chamber slide); (2) microscope (e.g. light source and microscope stage); (3) hardware and software, including the settings of each system; and (4) user-related factors. We review the effects of the different factors in each category on the measurements made and emphasise the need to take measures to standardise evaluations. The take-home message of the present article is that there are several commercial and useful CASA systems, and all are appropriate for routine analysis. Non-commercial systems may also be good choices when the user needs to adapt the device to specific experimental conditions. In both cases (commercial and non-commercial), it is important that standard protocols are put in place for evaluation, as well as methods to validate the system.

Effect of heat input on microstructure, wear and friction behavior of (wt.-%) 50FeCrC-20FeW-30FeB coating on AISI 1020 produced by using PTA welding

PubMed Central

Gürgenç, Turan

2018-01-01

In this study, AISI 1020 steel surface was coated in different heat inputs with (wt.-%) 50FeCrC-20FeW-30FeB powder mixture by using plasma transferred arc (PTA) welding method. The microstructure of the coated samples were investigated by using optical microscope (OM), scanning electron microscope (SEM), X-ray diffraction (XRD) and energy dispersive X-ray (EDS). The hardness was measured with micro hardness test device. The dry sliding wear and friction coefficient properties were determined using a block-on-disk type wear test device. Wear tests were performed at 19.62 N, 39.24 N, 58.86 N load and the sliding distance of 900 m. The results were shown that different microstructures formed due to the heat input change. The highest average micro hardness value was measured at 1217 HV on sample coated with low heat input. It was determined that the wear resistance decreased with increasing heat input. PMID:29324875

Virtual microscopy in virtual tumor banking.

PubMed

Isabelle, M; Teodorovic, I; Oosterhuis, J W; Riegman, P H J; Passioukov, A; Lejeune, S; Therasse, P; Dinjens, W N M; Lam, K H; Oomen, M H A; Spatz, A; Ratcliffe, C; Knox, K; Mager, R; Kerr, D; Pezzella, F; Van Damme, B; Van de Vijver, M; Van Boven, H; Morente, M M; Alonso, S; Kerjaschki, D; Pammer, J; López-Guerrero, J A; Llombart-Bosch, A; Carbone, A; Gloghini, A; Van Veen, E B

2006-01-01

Many systems have already been designed and successfully used for sharing histology images over large distances, without transfer of the original glass slides. Rapid evolution was seen when digital images could be transferred over the Internet. Nowadays, sophisticated virtual microscope systems can be acquired, with the capability to quickly scan large batches of glass slides at high magnification and compress and store the large images on disc, which subsequently can be consulted through the Internet. The images are stored on an image server, which can give simple, easy to transfer pictures to the user specifying a certain magnification on any position in the scan. This offers new opportunities in histology review, overcoming the necessity of the dynamic telepathology systems to have compatible software systems and microscopes and in addition, an adequate connection of sufficient bandwidth. Consulting the images now only requires an Internet connection and a computer with a high quality monitor. A system of complete pathology review supporting biorepositories is described, based on the implementation of this technique in the European Human Frozen Tumor Tissue Bank (TuBaFrost).

TuBaFrost 6: virtual microscopy in virtual tumour banking.

PubMed

Teodorovic, I; Isabelle, M; Carbone, A; Passioukov, A; Lejeune, S; Jaminé, D; Therasse, P; Gloghini, A; Dinjens, W N M; Lam, K H; Oomen, M H A; Spatz, A; Ratcliffe, C; Knox, K; Mager, R; Kerr, D; Pezzella, F; van Damme, B; van de Vijver, M; van Boven, H; Morente, M M; Alonso, S; Kerjaschki, D; Pammer, J; Lopez-Guerrero, J A; Llombart Bosch, A; van Veen, E-B; Oosterhuis, J W; Riegman, P H J

2006-12-01

Many systems have already been designed and successfully used for sharing histology images over large distances, without transfer of the original glass slides. Rapid evolution was seen when digital images could be transferred over the Internet. Nowadays, sophisticated Virtual Microscope systems can be acquired, with the capability to quickly scan large batches of glass slides at high magnification and compress and store the large images on disc, which subsequently can be consulted through the Internet. The images are stored on an image server, which can give simple, easy to transfer pictures to the user specifying a certain magnification on any position in the scan. This offers new opportunities in histology review, overcoming the necessity of the dynamic telepathology systems to have compatible software systems and microscopes and in addition, an adequate connection of sufficient bandwidth. Consulting the images now only requires an Internet connection and a computer with a high quality monitor. A system of complete pathology review supporting bio-repositories is described, based on the implementation of this technique in the European Human Frozen Tumor Tissue Bank (TuBaFrost).

Sputum smear microscopy: evaluation of impact of training, microscope distribution, and use of external quality assessment guidelines for resource-poor settings.

PubMed

Van Rie, A; Fitzgerald, D; Kabuya, G; Van Deun, A; Tabala, M; Jarret, N; Behets, F; Bahati, E

2008-03-01

Sputum smear microscopy is the main and often only laboratory technique used for the diagnosis of tuberculosis in resource-poor countries, making quality assurance (QA) of smear microscopy an important activity. We evaluated the effects of a 5-day refresher training course for laboratory technicians and the distribution of new microscopes on the quality of smear microscopy in 13 primary health care laboratories in Kinshasa, Democratic Republic of Congo. The 2002 external QA guidelines for acid-fast bacillus smear microscopy were implemented, and blinded rechecking of the slides was performed before and 9 months after the training course and microscope distribution. We observed that the on-site checklist was highly time-consuming but could be tailored to capture frequent problems. Random blinded rechecking by the lot QA system method decreased the number of slides to be reviewed. Most laboratories needed further investigation for possible unacceptable performance, even according to the least-stringent interpretation. We conclude that the 2002 external QA guidelines are feasible for implementation in resource-poor settings, that the efficiency of external QA can be increased by selecting sample size parameters and interpretation criteria that take into account the local working conditions, and that greater attention should be paid to the provision of timely feedback and correction of the causes of substandard performance at poorly performing laboratories.

AI (artificial intelligence) in histopathology--from image analysis to automated diagnosis.

PubMed

Kayser, Klaus; Görtler, Jürgen; Bogovac, Milica; Bogovac, Aleksandar; Goldmann, Torsten; Vollmer, Ekkehard; Kayser, Gian

2009-01-01

The technological progress in digitalization of complete histological glass slides has opened a new door in tissue--based diagnosis. The presentation of microscopic images as a whole in a digital matrix is called virtual slide. A virtual slide allows calculation and related presentation of image information that otherwise can only be seen by individual human performance. The digital world permits attachments of several (if not all) fields of view and the contemporary visualization on a screen. The presentation of all microscopic magnifications is possible if the basic pixel resolution is less than 0.25 microns. To introduce digital tissue--based diagnosis into the daily routine work of a surgical pathologist requires a new setup of workflow arrangement and procedures. The quality of digitized images is sufficient for diagnostic purposes; however, the time needed for viewing virtual slides exceeds that of viewing original glass slides by far. The reason lies in a slower and more difficult sampling procedure, which is the selection of information containing fields of view. By application of artificial intelligence, tissue--based diagnosis in routine work can be managed automatically in steps as follows: 1. The individual image quality has to be measured, and corrected, if necessary. 2. A diagnostic algorithm has to be applied. An algorithm has be developed, that includes both object based (object features, structures) and pixel based (texture) measures. 3. These measures serve for diagnosis classification and feedback to order additional information, for example in virtual immunohistochemical slides. 4. The measures can serve for automated image classification and detection of relevant image information by themselves without any labeling. 5. The pathologists' duty will not be released by such a system; to the contrary, it will manage and supervise the system, i.e., just working at a "higher level". Virtual slides are already in use for teaching and continuous education in anatomy and pathology. First attempts to introduce them into routine work have been reported. Application of AI has been established by automated immunohistochemical measurement systems (EAMUS, www.diagnomX.eu). The performance of automated diagnosis has been reported for a broad variety of organs at sensitivity and specificity levels >85%). The implementation of a complete connected AI supported system is in its childhood. Application of AI in digital tissue--based diagnosis will allow the pathologists to work as supervisors and no longer as primary "water carriers". Its accurate use will give them the time needed to concentrating on difficult cases for the benefit of their patients.

Magnification concepts: The use of video-probe microscopy to stimulate excitement and hands-on discovery in the science classroom K-12

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

Henk, C.; Garner, J.; Wandersee, J.H.

1994-12-31

We acquired and loaned several durable, easy-to use, though expensive video-probe microscopes. This hand-held, automatically focusing instrument can be used by a five year old and provides instant, excellent, in-focus images up to 200X on a video screen visible to all students simultaneously. The teacher is thus freed from the technical and logistic considerations involved in conventional classroom microscopy. K-12 teachers preview our videotape on probe utilization. They assemble and demonstrate the unit in the presence of our personnel, then check out the probe for use in their own classrooms. Extremely enthusiastic students examine samples ranging from their own fingerprintsmore » and clothing (on TV!) to pond water, prepared microscope slides, and microscope polarizing light phenomena. Teachers report heightened interest in conventional microscope use once the {open_quotes}microscopy connection{close_quotes} has been made.« less

A Randomized Study Comparing Digital Imaging to Traditional Glass Slide Microscopy for Breast Biopsy and Cancer Diagnosis

PubMed Central

Elmore, Joann G.; Longton, Gary M.; Pepe, Margaret S.; Carney, Patricia A.; Nelson, Heidi D.; Allison, Kimberly H.; Geller, Berta M.; Onega, Tracy; Tosteson, Anna N. A.; Mercan, Ezgi; Shapiro, Linda G.; Brunyé, Tad T.; Morgan, Thomas R.; Weaver, Donald L.

2017-01-01

Background: Digital whole slide imaging may be useful for obtaining second opinions and is used in many countries. However, the U.S. Food and Drug Administration requires verification studies. Methods: Pathologists were randomized to interpret one of four sets of breast biopsy cases during two phases, separated by ≥9 months, using glass slides or digital format (sixty cases per set, one slide per case, n = 240 cases). Accuracy was assessed by comparing interpretations to a consensus reference standard. Intraobserver reproducibility was assessed by comparing the agreement of interpretations on the same cases between two phases. Estimated probabilities of confirmation by a reference panel (i.e., predictive values) were obtained by incorporating data on the population prevalence of diagnoses. Results: Sixty-five percent of responding pathologists were eligible, and 252 consented to randomization; 208 completed Phase I (115 glass, 93 digital); and 172 completed Phase II (86 glass, 86 digital). Accuracy was slightly higher using glass compared to digital format and varied by category: invasive carcinoma, 96% versus 93% (P = 0.04); ductal carcinoma in situ (DCIS), 84% versus 79% (P < 0.01); atypia, 48% versus 43% (P = 0.08); and benign without atypia, 87% versus 82% (P < 0.01). There was a small decrease in intraobserver agreement when the format changed compared to when glass slides were used in both phases (P = 0.08). Predictive values for confirmation by a reference panel using glass versus digital were: invasive carcinoma, 98% and 97% (not significant [NS]); DCIS, 70% and 57% (P = 0.007); atypia, 38% and 28% (P = 0.002); and benign without atypia, 97% and 96% (NS). Conclusions: In this large randomized study, digital format interpretations were similar to glass slide interpretations of benign and invasive cancer cases. However, cases in the middle of the spectrum, where more inherent variability exists, may be more problematic in digital format. Future studies evaluating the effect these findings exert on clinical practice and patient outcomes are required. PMID:28382226

All-in-one 3D printed microscopy chamber for multidimensional imaging, the UniverSlide.

PubMed

Alessandri, Kevin; Andrique, Laetitia; Feyeux, Maxime; Bikfalvi, Andreas; Nassoy, Pierre; Recher, Gaëlle

2017-02-10

While live 3D high resolution microscopy techniques are developing rapidly, their use for biological applications is partially hampered by practical difficulties such as the lack of a versatile sample chamber. Here, we propose the design of a multi-usage observation chamber adapted for live 3D bio-imaging. We show the usefulness and practicality of this chamber, which we named the UniverSlide, for live imaging of two case examples, namely multicellular systems encapsulated in sub-millimeter hydrogel shells and zebrafish larvae. We also demonstrate its versatility and compatibility with all microscopy devices by using upright or inverted microscope configurations after loading the UniverSlide with fixed or living samples. Further, the device is applicable for medium/high throughput screening and automatized multi-position image acquisition, providing a constraint-free but stable and parallelized immobilization of the samples. The frame of the UniverSlide is fabricated using a stereolithography 3D printer, has the size of a microscopy slide, is autoclavable and sealed with a removable lid, which makes it suitable for use in a controlled culture environment. We describe in details how to build this chamber and we provide all the files necessary to print the different pieces in the lab.

All-in-one 3D printed microscopy chamber for multidimensional imaging, the UniverSlide

PubMed Central

Alessandri, Kevin; Andrique, Laetitia; Feyeux, Maxime; Bikfalvi, Andreas; Nassoy, Pierre; Recher, Gaëlle

2017-01-01

While live 3D high resolution microscopy techniques are developing rapidly, their use for biological applications is partially hampered by practical difficulties such as the lack of a versatile sample chamber. Here, we propose the design of a multi-usage observation chamber adapted for live 3D bio-imaging. We show the usefulness and practicality of this chamber, which we named the UniverSlide, for live imaging of two case examples, namely multicellular systems encapsulated in sub-millimeter hydrogel shells and zebrafish larvae. We also demonstrate its versatility and compatibility with all microscopy devices by using upright or inverted microscope configurations after loading the UniverSlide with fixed or living samples. Further, the device is applicable for medium/high throughput screening and automatized multi-position image acquisition, providing a constraint-free but stable and parallelized immobilization of the samples. The frame of the UniverSlide is fabricated using a stereolithography 3D printer, has the size of a microscopy slide, is autoclavable and sealed with a removable lid, which makes it suitable for use in a controlled culture environment. We describe in details how to build this chamber and we provide all the files necessary to print the different pieces in the lab. PMID:28186188

Current Status of Whole-Slide Imaging in Education.

PubMed

Saco, Adela; Bombi, Jose Antoni; Garcia, Adriana; Ramírez, Jose; Ordi, Jaume

2016-01-01

Conventional light microscopy (CLM) has classically been the basic tool to teach histology and pathology. In recent years, whole-slide imaging (WSI), which consists of generating a high-magnification digital image of an entire histological glass slide, has emerged as a useful alternative to CLM offering a myriad of opportunities for education. Navigation through the digitized slides closely simulates viewing glass slides with a microscope and is also referred to as virtual microscopy. WSI has many advantages for education. Students feel more comfortable with its use, and it can be used in any classroom as it only requires a computer with Internet access and it allows remote access from anywhere and from any device. WSI can be used simultaneously by a large number of people, stimulating cooperation between students and improving the interaction with the teachers. It allows making marks and annotations on specific fields, which enable specific directed questions to the teacher. Finally, WSI supports are cost-effective compared with CLM. Consequently, WSI has begun to replace CLM in many institutions. WSI has shown to be an extremely useful tool for undergraduate education (medical, dental and veterinary schools), for the training of residents of pathology, tele-education and in tumor boards. © 2016 S. Karger AG, Basel.

All-in-one 3D printed microscopy chamber for multidimensional imaging, the UniverSlide

NASA Astrophysics Data System (ADS)

Alessandri, Kevin; Andrique, Laetitia; Feyeux, Maxime; Bikfalvi, Andreas; Nassoy, Pierre; Recher, Gaëlle

2017-02-01

While live 3D high resolution microscopy techniques are developing rapidly, their use for biological applications is partially hampered by practical difficulties such as the lack of a versatile sample chamber. Here, we propose the design of a multi-usage observation chamber adapted for live 3D bio-imaging. We show the usefulness and practicality of this chamber, which we named the UniverSlide, for live imaging of two case examples, namely multicellular systems encapsulated in sub-millimeter hydrogel shells and zebrafish larvae. We also demonstrate its versatility and compatibility with all microscopy devices by using upright or inverted microscope configurations after loading the UniverSlide with fixed or living samples. Further, the device is applicable for medium/high throughput screening and automatized multi-position image acquisition, providing a constraint-free but stable and parallelized immobilization of the samples. The frame of the UniverSlide is fabricated using a stereolithography 3D printer, has the size of a microscopy slide, is autoclavable and sealed with a removable lid, which makes it suitable for use in a controlled culture environment. We describe in details how to build this chamber and we provide all the files necessary to print the different pieces in the lab.

Effect of differing PowerPoint slide design on multiple-choice test scores for assessment of knowledge and retention in a theriogenology course.

PubMed

Root Kustritz, Margaret V

2014-01-01

Third-year veterinary students in a required theriogenology diagnostics course were allowed to self-select attendance at a lecture in either the evening or the next morning. One group was presented with PowerPoint slides in a traditional format (T group), and the other group was presented with PowerPoint slides in the assertion-evidence format (A-E group), which uses a single sentence and a highly relevant graphic on each slide to ensure attention is drawn to the most important points in the presentation. Students took a multiple-choice pre-test, attended lecture, and then completed a take-home assignment. All students then completed an online multiple-choice post-test and, one month later, a different online multiple-choice test to evaluate retention. Groups did not differ on pre-test, assignment, or post-test scores, and both groups showed significant gains from pre-test to post-test and from pre-test to retention test. However, the T group showed significant decline from post-test to retention test, while the A-E group did not. Short-term differences between slide designs were most likely unaffected due to required coursework immediately after lecture, but retention of material was superior with the assertion-evidence slide design.

Effectiveness of an audience response system in teaching pharmacology to baccalaureate nursing students.

PubMed

Vana, Kimberly D; Silva, Graciela E; Muzyka, Diann; Hirani, Lorraine M

2011-06-01

It has been proposed that students' use of an audience response system, commonly called clickers, may promote comprehension and retention of didactic material. Whether this method actually improves students' grades, however, is still not determined. The purpose of this study was to evaluate whether a lecture format utilizing multiple-choice PowerPoint slides and an audience response system was more effective than a lecture format using only multiple-choice PowerPoint slides in the comprehension and retention of pharmacological knowledge in baccalaureate nursing students. The study also assessed whether the additional use of clickers positively affected students' satisfaction with their learning. Results from 78 students who attended lecture classes with multiple-choice PowerPoint slides plus clickers were compared with those of 55 students who utilized multiple-choice PowerPoint slides only. Test scores between these two groups were not significantly different. A satisfaction questionnaire showed that 72.2% of the control students did not desire the opportunity to use clickers. Of the group utilizing the clickers, 92.3% recommend the use of this system in future courses. The use of multiple-choice PowerPoint slides and an audience response system did not seem to improve the students' comprehension or retention of pharmacological knowledge as compared with those who used solely multiple-choice PowerPoint slides.

Optimal resolution in Fresnel incoherent correlation holographic fluorescence microscopy

PubMed Central

Brooker, Gary; Siegel, Nisan; Wang, Victor; Rosen, Joseph

2011-01-01

Fresnel Incoherent Correlation Holography (FINCH) enables holograms and 3D images to be created from incoherent light with just a camera and spatial light modulator (SLM). We previously described its application to microscopic incoherent fluorescence wherein one complex hologram contains all the 3D information in the microscope field, obviating the need for scanning or serial sectioning. We now report experiments which have led to the optimal optical, electro-optic, and computational conditions necessary to produce holograms which yield high quality 3D images from fluorescent microscopic specimens. An important improvement from our previous FINCH configurations capitalizes on the polarization sensitivity of the SLM so that the same SLM pixels which create the spherical wave simulating the microscope tube lens, also pass the plane waves from the infinity corrected microscope objective, so that interference between the two wave types at the camera creates a hologram. This advance dramatically improves the resolution of the FINCH system. Results from imaging a fluorescent USAF pattern and a pollen grain slide reveal resolution which approaches the Rayleigh limit by this simple method for 3D fluorescent microscopic imaging. PMID:21445140

[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.

Tribological properties of nanosized calcium carbonate filled polyamide 66 nanocomposites

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

Itagaki, Kaito; Nishitani, Yosuke; Kitano, Takeshi

For the purpose of developing high performance tribomaterials for mechanical sliding parts such as gears, bearings and so on, nanosized calcium carbonate (nano-CaCO{sub 3}) filled polyamide 66 (PA66) nanocomposites were investigated. The nano-CaCO{sub 3} was a kind of precipitated (colloid typed) CaCO{sub 3}, and its average particle size was 40, 80 and 150 nm. Surface treatment was performed by fatty acid on the nano-CaCO{sub 3} and its volume fraction in the nanocomposite was varied from 1 to 20vol.%. These nanocomposites were melt-mixed by a twin screw extruder and injection-molded. Tribological properties were measured by two types of sliding wear testers suchmore » as ring-on-plate type and ball-on-plate type one under dry condition. The counterface, worn surface and wear debris were observed by digital microscope and scanning electron microscope. It was found that the nano-CaCO{sub 3} has a good effect on the tribological properties, although the effect on the frictional coefficient and specific wear rate is differed by the volume fraction and the type of sliding wear modes. This is attributed to the change of wear mechanisms, which is the change of form of the transfer films on the counterface and the size of wear debris. It follows from these results that PA66/nano-CaCO{sub 3} nanocomposites may be possible to be the high performance tribomaterials.« less

High-recovery visual identification and single-cell retrieval of circulating tumor cells for genomic analysis using a dual-technology platform integrated with automated immunofluorescence staining.

PubMed

Campton, Daniel E; Ramirez, Arturo B; Nordberg, Joshua J; Drovetto, Nick; Clein, Alisa C; Varshavskaya, Paulina; Friemel, Barry H; Quarre, Steve; Breman, Amy; Dorschner, Michael; Blau, Sibel; Blau, C Anthony; Sabath, Daniel E; Stilwell, Jackie L; Kaldjian, Eric P

2015-05-06

Circulating tumor cells (CTCs) are malignant cells that have migrated from solid cancers into the blood, where they are typically present in rare numbers. There is great interest in using CTCs to monitor response to therapies, to identify clinically actionable biomarkers, and to provide a non-invasive window on the molecular state of a tumor. Here we characterize the performance of the AccuCyte®--CyteFinder® system, a comprehensive, reproducible and highly sensitive platform for collecting, identifying and retrieving individual CTCs from microscopic slides for molecular analysis after automated immunofluorescence staining for epithelial markers. All experiments employed a density-based cell separation apparatus (AccuCyte) to separate nucleated cells from the blood and transfer them to microscopic slides. After staining, the slides were imaged using a digital scanning microscope (CyteFinder). Precisely counted model CTCs (mCTCs) from four cancer cell lines were spiked into whole blood to determine recovery rates. Individual mCTCs were removed from slides using a single-cell retrieval device (CytePicker™) for whole genome amplification and subsequent analysis by PCR and Sanger sequencing, whole exome sequencing, or array-based comparative genomic hybridization. Clinical CTCs were evaluated in blood samples from patients with different cancers in comparison with the CellSearch® system. AccuCyte--CyteFinder presented high-resolution images that allowed identification of mCTCs by morphologic and phenotypic features. Spike-in mCTC recoveries were between 90 and 91%. More than 80% of single-digit spike-in mCTCs were identified and even a single cell in 7.5 mL could be found. Analysis of single SKBR3 mCTCs identified presence of a known TP53 mutation by both PCR and whole exome sequencing, and confirmed the reported karyotype of this cell line. Patient sample CTC counts matched or exceeded CellSearch CTC counts in a small feasibility cohort. The AccuCyte--CyteFinder system is a comprehensive and sensitive platform for identification and characterization of CTCs that has been applied to the assessment of CTCs in cancer patient samples as well as the isolation of single cells for genomic analysis. It thus enables accurate non-invasive monitoring of CTCs and evolving cancer biology for personalized, molecularly-guided cancer treatment.

Characterization of Dust on Solar Devices in Southern Nevada =

NASA Astrophysics Data System (ADS)

Sylva, Jason R.

Dust can impact the efficiency of solar energy collection devices, and in some arid environments, dust can reduce solar energy efficiency up to 30%. Reducing the impact of dust is therefore critical in the expansion of solar technology throughout regions where solar energy is utilized. Characterization of suspended and settled particulate matter can assist in developing strategies for dust mitigation. With the characterization of suspended and settled particulate in remote, rural, and urban environments, more informed decisions can be made regarding the selection of coating material on solar panels as well as developing cleaning and maintenance procedures. Particulate matter that deposits on a solar surface can potentially interact with solar radiation, precipitation, or even directly with the surface material itself. These interactions could lead to the formation of coatings that reduce/block radiation and/or degrade the integrity of the surface. When you extrapolate these possibilities to a larger scale preliminary characterization of dust will play a vital role when planning the construction of a solar energy facility. A variety of sampling techniques were employed to obtain particulate matter for characterization. These included direct collection of particulates from solar surfaces: via vacuum and wipe sample collection on panels, tacky dot adhesive slides and plain slides that were exposed at different intervals, desert vugs that are natural particulate collectors, as well as high volume air sampling for collection of suspended particulates. High volume air sampling was performed using glass fiber filters and 2 micron stainless steel screens. Direct collection of settled particulates was performed by sampling from solar surfaces, vugs, and by collection on exposed glass surfaces. Collection onto glass surfaces was achieved by setting up a plain microscope slide, tacky dot slides, and panes of glass. The sampling methodology allowed for the collection of samples for analyses using various analytical methods that included Raman microspectroscopy, pyrolysis gas chromatography mass spectrometry, ion chromatography and inductively coupled plasma mass spectrometry. These various methods allow for identification of organic and inorganic components as well the mineral distribution of suspended and settled particulate material. None None None None None

Investigation of the effects of sliding on wheel tread damage

DOT National Transportation Integrated Search

2005-11-05

Wheel tread spalling is the main source of damage to wheel treads and : a primary cause for wheel removals from service. Severe frictional : heating of the wheel-rail contact patch during sliding causes the : formation of martensite, a hard, brittle ...

Preliminary study of head-up assessment techniques. 1: Viewing duration of instrument panel and HUD symbology using a recall methodology

NASA Technical Reports Server (NTRS)

Haines, R. F.

1978-01-01

Eight commercial pilots were shown 50 colored, high fidelity slides of a standard instrument panel (IP) with the needle positions of each instrument varying from slide to slide and then 50 slides of a head-up display (HUD) symbology format which contained an equivalent amount of flight-related information as the instrument panel slides. All stimuli were presented under controlled, static viewing conditions that allowed the measurement of the speed and accuracy with which one randomly selected flight parameter on each slide could be read. The subject did not know which parameter would be requested and, therefore, had to remember the total set of information in order to answer the question correctly. The results showed that from 6.6 - 8.7 sec total viewing time was required to correctly extract altitude, airspeed, heading, VSI, or ADI from the IP slides and from 6.1 to 7.4 sec for the HUD slides.

Analyzing huge pathology images with open source software.

PubMed

Deroulers, Christophe; Ameisen, David; Badoual, Mathilde; Gerin, Chloé; Granier, Alexandre; Lartaud, Marc

2013-06-06

Digital pathology images are increasingly used both for diagnosis and research, because slide scanners are nowadays broadly available and because the quantitative study of these images yields new insights in systems biology. However, such virtual slides build up a technical challenge since the images occupy often several gigabytes and cannot be fully opened in a computer's memory. Moreover, there is no standard format. Therefore, most common open source tools such as ImageJ fail at treating them, and the others require expensive hardware while still being prohibitively slow. We have developed several cross-platform open source software tools to overcome these limitations. The NDPITools provide a way to transform microscopy images initially in the loosely supported NDPI format into one or several standard TIFF files, and to create mosaics (division of huge images into small ones, with or without overlap) in various TIFF and JPEG formats. They can be driven through ImageJ plugins. The LargeTIFFTools achieve similar functionality for huge TIFF images which do not fit into RAM. We test the performance of these tools on several digital slides and compare them, when applicable, to standard software. A statistical study of the cells in a tissue sample from an oligodendroglioma was performed on an average laptop computer to demonstrate the efficiency of the tools. Our open source software enables dealing with huge images with standard software on average computers. They are cross-platform, independent of proprietary libraries and very modular, allowing them to be used in other open source projects. They have excellent performance in terms of execution speed and RAM requirements. They open promising perspectives both to the clinician who wants to study a single slide and to the research team or data centre who do image analysis of many slides on a computer cluster. The virtual slide(s) for this article can be found here:http://www.diagnosticpathology.diagnomx.eu/vs/5955513929846272.

Does the ‘Old Bag’ Make a Good ‘Wind Bag’?: Comparison of Four Fabrics Commonly Used as Exclusion Bags in Studies of Pollination and Reproductive Biology

PubMed Central

NEAL, PAUL R.; ANDERSON, GREGORY J.

2004-01-01

• Background and Aims Fabrics used in pollination bags may exclude pollen carried by biotic vectors, but have varying degrees of permeability to wind‐borne pollen. The permeability of bags to wind‐borne pollen may have important consequences in studies of pollination and reproductive biology. The permeability of four fabrics commonly used in the construction of pollination bags was examined. • Methods Deposition of wind‐borne pollen on horizontally and vertically oriented microscope slides was assessed on slides enclosed in pollination bags, as well as on control slides. • Key Results It was found that the permeability of fabrics to wind‐borne pollen, as measured by deposition on both horizontally and vertically oriented slides, decreased with pore size. However, deposition on horizontal slides was always greater than on vertical slides for a given fabric; this could manifest itself as differential success of pollination of flowers in bags—dependent on flower orientation. • Conclusions Obviously, bags with mesh size smaller than most pollen grains are impermeable to pollen. However, material for such bags is very expensive. In addition, it was also observed that bags with even moderately small pore size, such as pores (approx. 200 µm) in twisted fibre cotton muslin, offered highly significant barriers to passage of wind‐borne pollen. Such bags are sufficiently effective in most large‐sample‐size reproductive biology studies. PMID:15037446

Automated Image Analysis Corrosion Working Group Update: February 1, 2018

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

Wendelberger, James G.

These are slides for the automated image analysis corrosion working group update. The overall goals were: automate the detection and quantification of features in images (faster, more accurate), how to do this (obtain data, analyze data), focus on Laser Scanning Confocal Microscope (LCM) data (laser intensity, laser height/depth, optical RGB, optical plus laser RGB).

A reliable method of analyzing dietaries of mycophagous small mammals

Treesearch

W. Colgan; A.B. Carey; James M. Trappe

1997-01-01

Two methods of analyzing the dietaries of mycophagous small mammals were compared. Fecal pellets were collected from 11 northern flying squirrels and 12 Townsend's chipmunks, all caught live. In 1 method, pellets from each individual were examined microscopically; in the other, samples from 3 or 4 individuals from each species were pooled and the number of slides...

Lowering coefficient of friction in Cu alloys with stable gradient nanostructures

PubMed Central

Chen, Xiang; Han, Zhong; Li, Xiuyan; Lu, K.

2016-01-01

The coefficient of friction (COF) of metals is usually high, primarily because frictional contacts induce plastic deformation underneath the wear surface, resulting in surface roughening and formation of delaminating tribolayers. Lowering the COF of metals is crucial for improving the reliability and efficiency of metal contacts in engineering applications but is technically challenging. Refining the metals’ grains to nanoscale cannot reduce dry-sliding COFs, although their hardness may be elevated many times. We report that a submillimeter-thick stable gradient nanograined surface layer enables a significant reduction in the COF of a Cu alloy under high-load dry sliding, from 0.64 (coarse-grained samples) to 0.29, which is smaller than the COFs of many ceramics. The unprecedented stable low COF stems from effective suppression of sliding-induced surface roughening and formation of delaminating tribolayer, owing to the stable gradient nanostructures that can accommodate large plastic strains under repeated sliding for more than 30,000 cycles. PMID:27957545

Use of interactive live digital imaging to enhance histology learning in introductory level anatomy and physiology classes.

PubMed

Higazi, Tarig B

2011-01-01

Histology is one of the main subjects in introductory college-level Human Anatomy and Physiology classes. Institutions are moving toward the replacement of traditional microscope-based histology learning with virtual microscopy learning amid concerns of losing the valuable learning experience of traditional microscopy. This study used live digital imaging (LDI) of microscopic slides on a SMART board to enhance Histology laboratory teaching. The interactive LDI system consists of a digital camera-equipped microscope that projects live images on a wall-mounted SMART board via a computer. This set-up allows real-time illustration of microscopic slides with highlighted key structural components, as well as the ability to provide the students with relevant study and review material. The impact of interactive LDI on student learning of Histology was then measured based on performance in subsequent laboratory tests before and after its implementation. Student grades increased from a mean of 76% (70.3-82.0, 95% CI) before to 92% (88.8-95.3, 95% CI) after integration of LDI indicating highly significant (P < 0.001) enhancement in students' Histology laboratory performance. In addition, student ratings of the impact of the interactive LDI on their Histology learning were strongly positive, suggesting that a majority of students who valued this learning approach also improved learning and understanding of the material as a result. The interactive LDI technique is an innovative, highly efficient and affordable tool to enhance student Histology learning, which is likely to expand knowledge and student perception of the subject and in turn enrich future science careers. Copyright © 2011 American Association of Anatomists.

A digital atlas of breast histopathology: an application of web based virtual microscopy

PubMed Central

Lundin, M; Lundin, J; Helin, H; Isola, J

2004-01-01

Aims: To develop an educationally useful atlas of breast histopathology, using advanced web based virtual microscopy technology. Methods: By using a robotic microscope and software adopted and modified from the aerial and satellite imaging industry, a virtual microscopy system was developed that allows fully automated slide scanning and image distribution via the internet. More than 150 slides were scanned at high resolution with an oil immersion ×40 objective (numerical aperture, 1.3) and archived on an image server residing in a high speed university network. Results: A publicly available website was constructed, http://www.webmicroscope.net/breastatlas, which features a comprehensive virtual slide atlas of breast histopathology according to the World Health Organisation 2003 classification. Users can view any part of an entire specimen at any magnification within a standard web browser. The virtual slides are supplemented with concise textual descriptions, but can also be viewed without diagnostic information for self assessment of histopathology skills. Conclusions: Using the technology described here, it is feasible to develop clinically and educationally useful virtual microscopy applications. Web based virtual microscopy will probably become widely used at all levels in pathology teaching. PMID:15563669

Distinct roles of 1α and 1β heavy chains of the inner arm dynein I1 of Chlamydomonas flagella

PubMed Central

Toba, Shiori; Fox, Laura A.; Sakakibara, Hitoshi; Porter, Mary E.; Oiwa, Kazuhiro; Sale, Winfield S.

2011-01-01

The Chlamydomonas I1 dynein is a two-headed inner dynein arm important for the regulation of flagellar bending. Here we took advantage of mutant strains lacking either the 1α or 1β motor domain to distinguish the functional role of each motor domain. Single- particle electronic microscopic analysis confirmed that both the I1α and I1β complexes are single headed with similar ringlike, motor domain structures. Despite similarity in structure, however, the I1β complex has severalfold higher ATPase activity and microtubule gliding motility compared to the I1α complex. Moreover, in vivo measurement of microtubule sliding in axonemes revealed that the loss of the 1β motor results in a more severe impairment in motility and failure in regulation of microtubule sliding by the I1 dynein phosphoregulatory mechanism. The data indicate that each I1 motor domain is distinct in function: The I1β motor domain is an effective motor required for wild-type microtubule sliding, whereas the I1α motor domain may be responsible for local restraint of microtubule sliding. PMID:21148301

An Efficient Covalent Coating on Glass Slides for Preparation of Optical Oligonucleotide Microarrays

PubMed Central

Pourjahed, Atefeh; Rabiee, Mohammad; Tahriri, Mohammadreza

2013-01-01

Objective(s): Microarrays are potential analyzing tools for genomics and proteomics researches, which is in needed of suitable substrate for coating and also hybridization of biomolecules. Materials and Methods: In this research, a thin film of oxidized agarose was prepared on the glass slides which previously coated with poly-L-lysine (PLL). Some of the aldehyde groups of the activated agarose linked covalently to PLL amine groups; also bound to the amino groups of biomolecules. These linkages were fixed by UV irradiation. The prepared substrates were compared to only agarose-coated and PLL-coated slides. Results: Results on atomic force microscope (AFM) demonstrated that agarose provided three-dimensional surface which had higher loading and bindig capacity for biomolecules than PLL-coated surface which had two-dimensional surface. In addition, the signal-to-noise ratio in hybridization reactions performed on the agarose-PLL coated substrates increased two fold and four fold compared to agarose and PLL coated substrates, respectively. Conclusion: The agarose-PLL microarrays had the highest signal (2546) and lowest background signal (205) in hybridization, suggesting that the prepared slides are suitable in analyzing wide concentration range of analytes. PMID:24570832

Ten simple rules for Lightning and PechaKucha presentations.

NASA Astrophysics Data System (ADS)

Lortie, C. J.

2016-12-01

An interesting opportunity has emerged that bridges the gap between lengthy, detailed presentations of scientific findings and `sound bites' appropriate for media reporting - very short presentations often presented in sets. Lightning or Ignite (20 slides @15 seconds each) and PechaKucha (20 slides @20 seconds each) presentations are common formats for short, rapid communications at scientific conferences and public events. The simple rules for making good presentations also apply, but these presentation formats provide both unique communication opportunities and novel challenges. In the spirit of light, quick, and exact (but without the fox), here are ten simple rules for presentation formats that do not wait for the speaker.

Experimental Germ Tube Induction in Candida albicans: An Evaluation of the Effect of Sodium Bicarbonate on Morphogenesis and Comparison with Pooled Human Serum.

PubMed

Matare, Tapiwa; Nziramasanga, Pasipanodya; Gwanzura, Lovemore; Robertson, Valerie

2017-01-01

The potential of NaHCO 3 versus human serum to induce germ tube formation in Candida albicans was investigated. A total of 100 isolates were obtained from oral swabs of patients presenting with thrush. Approval for the study was granted by the Joint Research Ethics Committee (JREC/23/08). Confirmed C. albicans isolates by routine methods were tested for germ tube induction using 5 different concentrations of Tris-maleate buffered NaHCO 3 and Tris-maleate buffer control. Standard control strains included were C. albicans (ATCC 10231) and C. krusei (ATCC 6258). Microculture was done in 20  μ L inoculums on microscope slides for 3 hours at 37°C. The rate of germ tube formation at 10-minute intervals was determined on 100 isolates using the optimum 20 mM Tris-maleate buffered NaHCO 3 concentration. Parallel germ tube formation using human serum was done in test tubes. The optimum concentration of NaHCO 3 in Tris-maleate buffer for germ tube induction was 20 mM for 67% of isolates. Only 21% of isolates formed germ tubes in Tris-maleate buffer control. There was no significant difference in induction between human serum and Tris-maleate buffered NaHCO 3 . Tris-maleate buffered NaHCO 3 induced germ tube formation in C. albicans isolates at rates similar to human serum.

The European Micropaleontological Reference Centre in Kraków

NASA Astrophysics Data System (ADS)

Kaminski, Michael; Waskowska, Anna; Bebenek, Slawomir; Pilarz, Monika

2016-04-01

We are pleased to announce the establishment of the European Micropaleontological Reference Centre, housed in the offices of Micropress Europe at the AGH University of Science & Technology in Krakow, Poland. The new European Micropaleontological Reference Centre is an initiative of the Grzybowski Foundation and Micropress Europe. The centre is designed to serve the micropaleontological community by providing a permanent repository or "museum" for published microfossil collections. The centre houses a growing collection of microfossils picked into faunal slides, as well as a well-stocked library of micropaleontological books, journals, and reprints. We have the only up-to-date paper copy of the Ellis & Messina Catalogue of Foraminifera in Central Europe. Currently, the slide collections include: - Type slides of benthic foraminifera from Poland (the collection of I. Heller from the Polish oil company GEONAFTA), - Carboniferous foraminifera from Germany and Poland (collections of G. Eickhoff and Z. Alexandrowicz), - IODP sites in the Arctic, Atlantic, and Indian Oceans (collections of M. Kaminski, E. Setoyama, A. Holborn), - Exploration wells in the Boreal seas: North Sea, Norwegian Sea, Western Barents Sea, Labrador Sea, Bering Sea, Spitsbergen, Western Siberia (collections of M. Kaminski, J. Nagy, T. Van Den Akker, V. Podobina, and others), - Paratethyan Foraminifera (collections of E. Luczkowska, C. Beldean, F. Szekely), - Mesozoic-Paleogene Foraminifera from Gubbio, Italy (collections of M. Kaminski, C. Cetean, and students) and the Polish Carpathians (collection of A. Waskowska), - Caribbean (collection of M. Kaminski, R. Preece), West Africa (collection of R. Preece, S. Kender, C. Cetean), - We have a separate collection of type specimens of species (paratypes). Slides are housed in cabinet drawers together with the relevant publication. Researchers are welcome to visit the offices of Micropress Europe to view the archived microfossil collections. The center has purchased new binocular microscopes, and has access to the Scanning Electron Microscope Lab at AGH. Viewing is by appointment, and can be arranged by sending an email to [info@micropresseurope.eu].

Virtual microscopy: an evaluation of its validity and diagnostic performance in routine histologic diagnosis of skin tumors.

PubMed

Nielsen, Patricia Switten; Lindebjerg, Jan; Rasmussen, Jan; Starklint, Henrik; Waldstrøm, Marianne; Nielsen, Bjarne

2010-12-01

Digitization of histologic slides is associated with many advantages, and its use in routine diagnosis holds great promise. Nevertheless, few articles evaluate virtual microscopy in routine settings. This study is an evaluation of the validity and diagnostic performance of virtual microscopy in routine histologic diagnosis of skin tumors. Our aim is to investigate whether conventional microscopy of skin tumors can be replaced by virtual microscopy. Ninety-six skin tumors and skin-tumor-like changes were consecutively gathered over a 1-week period. Specimens were routinely processed, and digital slides were captured on Mirax Scan (Carl Zeiss MicroImaging, Göttingen, Germany). Four pathologists evaluated the 96 virtual slides and the associated 96 conventional slides twice with intermediate time intervals of at least 3 weeks. Virtual slides that caused difficulties were reevaluated to identify possible reasons for this. The accuracy was 89.2% for virtual microscopy and 92.7% for conventional microscopy. All κ coefficients expressed very good intra- and interobserver agreement. The sensitivities were 85.7% (78.0%-91.0%) and 92.0% (85.5%-95.7%) for virtual and conventional microscopy, respectively. The difference between the sensitivities was 6.3% (0.8%-12.6%). The subsequent reevaluation showed that virtual slides were as useful as conventional slides when rendering a diagnosis. Differences seen are presumed to be due to the pathologists' lack of experience using the virtual microscope. We conclude that it is feasible to make histologic diagnosis on the skin tumor types represented in this study using virtual microscopy after pathologists have completed a period of training. Larger studies should be conducted to verify whether virtual microscopy can replace conventional microscopy in routine practice. Copyright © 2010 Elsevier Inc. All rights reserved.

Wirelessly powered microfluidic dielectrophoresis devices using printable RF circuits.

PubMed

Qiao, Wen; Cho, Gyoujin; Lo, Yu-Hwa

2011-03-21

We report the first microfluidic device integrated with a printed RF circuit so the device can be wirelessly powered by a commercially available RFID reader. For conventional dielectrophoresis devices, electrical wires are needed to connect the electric components on the microchip to external equipment such as power supplies, amplifiers, function generators, etc. Such a procedure is unfamiliar to most clinicians and pathologists who are used to working with a microscope for examination of samples on microscope slides. The wirelessly powered device reported here eliminates the entire need for wire attachments and external instruments so the operators can use the device in essentially the same manner as they do with microscope slides. The integrated circuit can be fabricated on a flexible plastic substrate at very low cost using a roll-to-roll printing method. Electrical power at 13.56 MHz transmitted by a radio-frequency identification (RFID) reader is inductively coupled to the printed RFIC and converted into 10 V DC (direct current) output, which provides sufficient power to drive a microfluidic device to manipulate biological particles such as beads and proteins via the DC dielectrophoresis (DC-DEP) effect. To our best knowledge, this is the first wirelessly powered microfluidic dielectrophoresis device. Although the work is preliminary, the device concept, the architecture, and the core technology are expected to stimulate many efforts in the future and transform the technology to a wide range of clinical and point-of-care applications. This journal is © The Royal Society of Chemistry 2011

Mechanism for circularization of linear DNAs: circular parvovirus MVM DNA is formed by a "noose" sliding in a "lasso"-like DNA structure.

PubMed

Bratosin, S; Laub, O; Tal, J; Aloni, Y

1979-09-01

During an electron-microscopic survey with the aim of identifying the parvovirus MVM transcription template, we observed previously unidentified structures of MVM DNA in lysates of virus-infected cells. These included double-stranded "lasso"-like structures and relaxed circles. Both structures were of unit length MVM DNA, indicating that they were not intermediates formed during replication; they each represented about 5% of the total nuclear MVM DNA. The proportion of these structures was unchanged after digestion with sodium dodecyl sulfate/Pronase and RNase and after mild denaturation treatment. Cleavage of the "lasso" structures with EcoRI restriction endonuclease indicated that the "noose" part of the "lasso" structure is located on the 5' side of the genomic single-stranded MVM DNA. A model is presented for the molecular nature of the circularization process of MVM DNA in which the "lasso" structures are identified as intermediates during circle formation. This model proposes a mechanism for circularization of linear DNAs.

Specimen illumination apparatus with optical cavity for dark field illumination

DOEpatents

Pinkel, Daniel; Sudar, Damir; Albertson, Donna

1999-01-01

An illumination apparatus with a specimen slide holder, an illumination source, an optical cavity producing multiple reflection of illumination light to a specimen comprising a first and a second reflective surface arranged to achieve multiple reflections of light to a specimen is provided. The apparatus can further include additional reflective surfaces to achieve the optical cavity, a slide for mounting the specimen, a coverslip which is a reflective component of the optical cavity, one or more prisms for directing light within the optical cavity, antifading solutions for improving the viewing properties of the specimen, an array of materials for analysis, fluorescent components, curved reflective surfaces as components of the optical cavity, specimen detection apparatus, optical detection equipment, computers for analysis of optical images, a plane polarizer, fiberoptics, light transmission apertures, microscopic components, lenses for viewing the specimen, and upper and lower mirrors above and below the specimen slide as components of the optical cavity. Methods of using the apparatus are also provided.

[Virtual microscopy in pathology teaching and postgraduate training (continuing education)].

PubMed

Sinn, H P; Andrulis, M; Mogler, C; Schirmacher, P

2008-11-01

As with conventional microscopy, virtual microscopy permits histological tissue sections to be viewed on a computer screen with a free choice of viewing areas and a wide range of magnifications. This, combined with the possibility of linking virtual microscopy to E-Learning courses, make virtual microscopy an ideal tool for teaching and postgraduate training in pathology. Uses of virtual microscopy in pathology teaching include blended learning with the presentation of digital teaching slides in the internet parallel to presentation in the histology lab, extending student access to histology slides beyond the lab. Other uses are student self-learning in the Internet, as well as the presentation of virtual slides in the classroom with or without replacing real microscopes. Successful integration of virtual microscopy depends on its embedding in the virtual classroom and the creation of interactive E-learning content. Applications derived from this include the use of virtual microscopy in video clips, podcasts, SCORM modules and the presentation of virtual microscopy using interactive whiteboards in the classroom.

Succession and physiological health of freshwater microalgal fouling in a Tasmanian hydropower canal.

PubMed

Perkins, Kathryn J; Andrewartha, Jessica M; McMinn, Andrew; Cook, Suellen S; Hallegraeff, Gustaaf M

2010-08-01

Freshwater microalgal biofouling in hydropower canals in Tarraleah, Tasmania, is dominated by a single diatom species, Gomphonema tarraleahae. The microfouling community is under investigation with the aim of reducing its impact on electricity generation. Species succession was investigated using removable glass slides. Fouled slides were examined microscopically and for chlorophyll a biomass. Chl a biomass increased steeply after 8 weeks (0.09-0.87 mg m(-2)), but increased much earlier on slides surrounded by a biofouled inoculum. Succession began with low profile diatoms such as Tabellaria flocculosa, progressing to stalked diatoms such as Gomphonema spp. and Cymbella aspera. Few chlorophytes and no filamentous algae were present. Pulse amplitude modulated fluorometry was used to measure the physiological health of fouling on the canal wall. Maximum quantum yield (F(v)/F(m)) measurements were consistently <0.18, indicating that the fouling mat consisted of dead or dying algae. The succession and physiological health of cells in the fouling community has broad implications for mitigation techniques used.

Friction and Wear on the Atomic Scale

NASA Astrophysics Data System (ADS)

Gnecco, Enrico; Bennewitz, Roland; Pfeiffer, Oliver; Socoliuc, Anisoara; Meyer, Ernst

Friction has long been the subject of research: the empirical da Vinci-Amontons friction laws have been common knowledge for centuries. Macroscopic experiments performed by the school of Bowden and Tabor revealed that macroscopic friction can be related to the collective action of small asperities. Over the last 15 years, experiments performed with the atomic force microscope have provided new insights into the physics of single asperities sliding over surfaces. This development, together with the results from complementary experiments using surface force apparatus and the quartz microbalance, have led to the new field of nanotribology. At the same time, increasing computing power has permitted the simulation of processes that occur during sliding contact involving several hundreds of atoms. It has become clear that atomic processes cannot be neglected when interpreting nanotribology experiments. Even on well-defined surfaces, experiments have revealed that atomic structure is directly linked to friction force. This chapter will describe friction force microscopy experiments that reveal, more or less directly, atomic processes during sliding contact.

High-temperature friction and wear studies of Fe-Cu-Sn alloy with graphite as solid lubricant under dry sliding conditions

NASA Astrophysics Data System (ADS)

Mushtaq, Shuhaib; Wani, M. F.

2018-02-01

Solid lubricants are particularly used in the advanced mechanical motion systems with extreme conditions such as (high temperature, vacuum, radiation, extreme contact pressure, etc). The main focus of this paper is to study the dry sliding friction and wear behavior of Fe-Cu-Sn alloy with varying wt% of graphite at high temperature up to 423 K. The influence of temperature, sliding distance and load on friction and wear behavior of Fe-Cu-Sn alloy against EN8 steel was studied using ball (EN8) on disc (Fe-Cu-Sn alloy). Lower wear and lower friction of Fe-Cu-Sn alloy were observed at high temperature, as compared to room temperature. Surface morphological and surface analytical studies of fresh and worn surfaces were carried out using optical microscopy, 3D profilometer, scanning electron microscope, energy dispersive x-ray spectroscopy, XRD, and Raman spectroscopy to understand the friction and wear behavior.

Development of a low-cost x-ray mask for high-aspect-ratio MEM smart structures

NASA Astrophysics Data System (ADS)

Ajmera, Pratul K.; Stadler, Stefan; Abdollahi, Neda

1998-07-01

A cost-effective process with short fabrication time for making x-ray masks for research and development purposes is described here for fabricating high-aspect ratio microelectromechanical structures using synchrotron based x- ray lithography. Microscope cover glass slides as membrane material is described. Slides with an initial thickness of 175 micrometers are etched to a thickness in the range of 10 - 25 micrometers using a diluted HF and buffered hydrofluoric acid solutions. The thinned slides are glued on supportive mask frames and sputtered with a chromium/silver sandwich layer which acts as a plating base layer for the deposition of the gold absorber. The judicial choice of glue and mask frame material are significant parameters in a successful fabrication process. Gold absorber structures are electroplated on the membrane. Calculations are done for contrast and dose ratio obtained in the photoresist after synchrotron radiation as a function of the mask design parameters. Exposure experiments are performed to prove the applicability of the fabricated x-ray mask.

Teacher's Guide to Aviation Education Resources. Including: Career Information, Audiovisuals, Publications, Periodicals.

ERIC Educational Resources Information Center

Federal Aviation Administration (DOT), Washington, DC. Office of Public Affairs.

Currently available aviation education resource materials are listed alphabetically by title under four headings: (1) career information; (2) audiovisual materials; (3) publications; and (4) periodicals. Each entry includes: title; format (16mm film, slides, slide/tape presentation, VHS/Beta videotape, book, booklet, newsletter, pamphlet, poster,…

Effect of strain hardening on friction behavior of iron lubricated with benzyl structures

NASA Technical Reports Server (NTRS)

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

1974-01-01

Sliding friction experiments were conducted with iron, copper, and aluminum in contact with iron in various states of strain. The surfaces were examined in dry sliding and with various benzyl compounds applied as lubricants. Friction experiments were conducted with a hemispherical rider contacting a flat disk at loads of from 50 to 600 grams with a sliding speed of 0.15 cm/min. Results indicate that straining increases friction for dry sliding and for surfaces lubricated with certain benzyl structures such as dibenzyl disulfide. With other benzyl compounds (e.g., benzyl formate), friction coefficients are lower for strained than for annealed iron.

Measurement of Trap Length for an Optical Trap

NASA Technical Reports Server (NTRS)

Wrbanek, Susan Y.

2009-01-01

The trap length along the beam axis for an optical trap formed with an upright, oil-immersion microscope was measured. The goals for this effort were twofold. It was deemed useful to understand the depth to which an optical trap can reach for purposes of developing a tool to assist in the fabrication of miniature devices. Additionally, it was desired to know whether the measured trap length favored one or the other of two competing theories to model an optical trap. The approach was to trap a microsphere of known size and mass and raise it from its initial trap position. The microsphere was then dropped by blocking the laser beam for a pre-determined amount of time. Dropping the microsphere in a free-fall mode from various heights relative to the coverslip provides an estimate of how the trapping length changes with depth in water in a sample chamber on a microscope slide. While it was not possible to measure the trap length with sufficient precision to support any particular theory of optical trap formation, it was possible to find regions where the presence of physical boundaries influenced optical traps, and determine that the trap length, for the apparatus studied, is between 6 and 7 m. These results allow more precise control using optical micromanipulation to assemble miniature devices by providing information about the distance over which an optical trap is effective.

Porous Thin Films Based on Photo-Cross-Linked Star-Shaped Poly(D,L-lactide)s

DTIC Science & Technology

2007-03-01

with nitrogen. The Kapton substrate was taped to a glass microscope slide and then positioned in the humidity chamber. A few drops of PDLLA or PDLLA-UM...Yabu, H.; Tanaka, M.; Ijiro, K.; Shimomura, M. Langmuir 2003, 19, 6297-6300. (36) Erdogan , B.; Song, L.; Wilson, J. N.; Park, J. O.; Srinivasarao, M

A Prospective, Randomized Crossover Study Comparing Direct Inspection by Light Microscopy versus Projected Images for Teaching of Hematopathology to Medical Students

ERIC Educational Resources Information Center

Carlson, Aaron M.; McPhail, Ellen D.; Rodriguez, Vilmarie; Schroeder, Georgene; Wolanskyj, Alexandra P.

2014-01-01

Instruction in hematopathology at Mayo Medical School has evolved from instructor-guided direct inspection under the light microscope (laboratory method), to photomicrographs of glass slides with classroom projection (projection method). These methods have not been compared directly to date. Forty-one second-year medical students participated in…

An Undergraduate Laboratory Exercise to Study the Effect of Darkness on Plant Gene Expression Using DNA Microarray

ERIC Educational Resources Information Center

Chang, Ming-Mei; Briggs, George M.

2007-01-01

DNA microarrays are microscopic arrays on a solid surface, typically a glass slide, on which DNA oligonucleotides are deposited or synthesized in a high-density matrix with a predetermined spatial order. Several types of DNA microarrays have been developed and used for various biological studies. Here, we developed an undergraduate laboratory…

Detection of radiation treatment of beans using DNA comet assay

NASA Astrophysics Data System (ADS)

Khan, Ashfaq A.; Khan, Hasan M.; Delincée, Henry

2002-03-01

A simple technique of microgel electrophoresis of single cells (DNA Comet Assay) enabled a quick detection of radiation treatment of several kinds of leguminous beans (azuki, black, black eye, mung, pinto, red kidney and white beans). Each variety was exposed to radiation doses of 0.5, 1 and 5kGy covering the permissible limits for insect disinfestation. The cells or nuclei from beans were extracted in cold PBS, embedded in agarose on microscope slides, lysed between 15 and 60min in 2.5% SDS and electrophoresis was carried out at a voltage of 2V/cm for 2-2.5min. After silver staining, the slides were evaluated through an ordinary transmission microscope. In irradiated samples, fragmented DNA stretched towards the anode and the damaged cells appeared as a comet. The density of DNA in the tails increased with increasing radiation dose. However, in non-irradiated samples, the large molecules of DNA remained relatively intact and there was only minor or no migration of DNA; the cells were round or had very short tails only. Hence, the DNA comet assay provides an inexpensive, rapid and relatively simple screening method for the detection of irradiated beans.

Novel Slide-Ring Material/Natural Rubber Composites with High Damping Property

PubMed Central

Wang, Wencai; Zhao, Detao; Yang, Jingna; Nishi, Toshio; Ito, Kohzo; Zhao, Xiuying; Zhang, Liqun

2016-01-01

A novel class of polymers called “slide-ring” (SR) materials with slideable junctions were used for high damping composites for the first time. The SR acts as the high damping phase dispersed in the natural rubber (NR) matrix, and epoxidized natural rubber (ENR) acts as the compatibilizer. The morphological, structural, and mechanical properties of the composites were investigated by atomic force microscope (AFM), transmission electron microscope (TEM), dynamic mechanical thermal analyzer (DMTA), rubber processing analyzer (RPA), and tensile tester. AFM and TEM results showed that the SR phase was uniformly dispersed in the composites, in a small size that is a function of ENR. DMTA and RPA results showed that the damping factor of the composites is much higher than that of NR, especially at room temperatures. Stretch hysteresis was used to study the energy dissipation of the composites at large strains. The results showed that SR and ENR can significantly improve the dissipation efficiency at strains lower than 200% strain. Wide-angle X-ray diffraction was used to study the strain-induced crystallization of the composites. The results indicated that the impact of the SR on the crystallization of NR is mitigated by the insulating effect of ENR. PMID:26949077

Modified global and modified linear contrast stretching algorithms: new colour contrast enhancement techniques for microscopic analysis of malaria slide images.

PubMed

Abdul-Nasir, Aimi Salihah; Mashor, Mohd Yusoff; Mohamed, Zeehaida

2012-01-01

Malaria is one of the serious global health problem, causing widespread sufferings and deaths in various parts of the world. With the large number of cases diagnosed over the year, early detection and accurate diagnosis which facilitates prompt treatment is an essential requirement to control malaria. For centuries now, manual microscopic examination of blood slide remains the gold standard for malaria diagnosis. However, low contrast of the malaria and variable smears quality are some factors that may influence the accuracy of interpretation by microbiologists. In order to reduce this problem, this paper aims to investigate the performance of the proposed contrast enhancement techniques namely, modified global and modified linear contrast stretching as well as the conventional global and linear contrast stretching that have been applied on malaria images of P. vivax species. The results show that the proposed modified global and modified linear contrast stretching techniques have successfully increased the contrast of the parasites and the infected red blood cells compared to the conventional global and linear contrast stretching. Hence, the resultant images would become useful to microbiologists for identification of various stages and species of malaria.

Malaria diagnosis under field conditions in the Venezuelan Amazon.

PubMed

Metzger, W G; Vivas-Martínez, S; Rodriguez, I; Gonçalves, J; Bongard, E; Fanello, C I; Vivas, L; Magris, M

2008-01-01

To improve practical, accurate diagnosis of malaria in the Amazon rainforest of Venezuela, two rapid diagnostic tests (RDT) (OptiMAL-IT) and FalciVax) and a laboratory light microscope, used in the field with a battery-operated head lamp as an external light source, were evaluated against the standard laboratory microscope procedure for malaria detection. One hundred and thirty-six Yanomami patients were studied for the presence of malaria parasites. Thirty-three patients (24%) were positive for malaria (Plasmodium falciparum, P. vivax, P. malariae). Twenty-one (64%) of the positive patients had <100 parasites/microl. Both RDTs showed poor sensitivity (24.2% for OptiMAL-IT) and 36.4% for FalciVax) but good specificity (99% both for OptiMAL-IT) and FalciVax). Field and laboratory microscopy showed sensitivities of 94% and 91%, respectively. The kappa coefficient was 0.90, indicating a high agreement between field and laboratory microscopy. We conclude that (i) adequate slide reading cannot be substituted by either of the two RDTs in the Venezuelan Amazon and (ii) the use of a light source such as that described above makes slide reading more feasible than hitherto in remote areas without electricity.

Development of a Whole Slide Imaging System on Smartphones and Evaluation With Frozen Section Samples.

PubMed

Yu, Hong; Gao, Feng; Jiang, Liren; Ma, Shuoxin

2017-09-15

The aim was to develop scalable Whole Slide Imaging (sWSI), a WSI system based on mainstream smartphones coupled with regular optical microscopes. This ultra-low-cost solution should offer diagnostic-ready imaging quality on par with standalone scanners, supporting both oil and dry objective lenses of different magnifications, and reasonably high throughput. These performance metrics should be evaluated by expert pathologists and match those of high-end scanners. The aim was to develop scalable Whole Slide Imaging (sWSI), a whole slide imaging system based on smartphones coupled with optical microscopes. This ultra-low-cost solution should offer diagnostic-ready imaging quality on par with standalone scanners, supporting both oil and dry object lens of different magnification. All performance metrics should be evaluated by expert pathologists and match those of high-end scanners. In the sWSI design, the digitization process is split asynchronously between light-weight clients on smartphones and powerful cloud servers. The client apps automatically capture FoVs at up to 12-megapixel resolution and process them in real-time to track the operation of users, then give instant feedback of guidance. The servers first restitch each pair of FoVs, then automatically correct the unknown nonlinear distortion introduced by the lens of the smartphone on the fly, based on pair-wise stitching, before finally combining all FoVs into one gigapixel VS for each scan. These VSs can be viewed using Internet browsers anywhere. In the evaluation experiment, 100 frozen section slides from patients randomly selected among in-patients of the participating hospital were scanned by both a high-end Leica scanner and sWSI. All VSs were examined by senior pathologists whose diagnoses were compared against those made using optical microscopy as ground truth to evaluate the image quality. The sWSI system is developed for both Android and iPhone smartphones and is currently being offered to the public. The image quality is reliable and throughput is approximately 1 FoV per second, yielding a 15-by-15 mm slide under 20X object lens in approximately 30-35 minutes, with little training required for the operator. The expected cost for setup is approximately US $100 and scanning each slide costs between US $1 and $10, making sWSI highly cost-effective for infrequent or low-throughput usage. In the clinical evaluation of sample-wise diagnostic reliability, average accuracy scores achieved by sWSI-scan-based diagnoses were as follows: 0.78 for breast, 0.88 for uterine corpus, 0.68 for thyroid, and 0.50 for lung samples. The respective low-sensitivity rates were 0.05, 0.05, 0.13, and 0.25 while the respective low-specificity rates were 0.18, 0.08, 0.20, and 0.25. The participating pathologists agreed that the overall quality of sWSI was generally on par with that produced by high-end scanners, and did not affect diagnosis in most cases. Pathologists confirmed that sWSI is reliable enough for standard diagnoses of most tissue categories, while it can be used for quick screening of difficult cases. As an ultra-low-cost alternative to whole slide scanners, diagnosis-ready VS quality and robustness for commercial usage is achieved in the sWSI solution. Operated on main-stream smartphones installed on normal optical microscopes, sWSI readily offers affordable and reliable WSI to resource-limited or infrequent clinical users. ©Hong Yu, Feng Gao, Liren Jiang, Shuoxin Ma. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 15.09.2017.

Reliable Detection and Smart Deletion of Malassez Counting Chamber Grid in Microscopic White Light Images for Microbiological Applications.

PubMed

Denimal, Emmanuel; Marin, Ambroise; Guyot, Stéphane; Journaux, Ludovic; Molin, Paul

2015-08-01

In biology, hemocytometers such as Malassez slides are widely used and are effective tools for counting cells manually. In a previous work, a robust algorithm was developed for grid extraction in Malassez slide images. This algorithm was evaluated on a set of 135 images and grids were accurately detected in most cases, but there remained failures for the most difficult images. In this work, we present an optimization of this algorithm that allows for 100% grid detection and a 25% improvement in grid positioning accuracy. These improvements make the algorithm fully reliable for grid detection. This optimization also allows complete erasing of the grid without altering the cells, which eases their segmentation.

Quantitative phase imaging of arthropods

PubMed Central

Sridharan, Shamira; Katz, Aron; Soto-Adames, Felipe; Popescu, Gabriel

2015-01-01

Abstract. Classification of arthropods is performed by characterization of fine features such as setae and cuticles. An unstained whole arthropod specimen mounted on a slide can be preserved for many decades, but is difficult to study since current methods require sample manipulation or tedious image processing. Spatial light interference microscopy (SLIM) is a quantitative phase imaging (QPI) technique that is an add-on module to a commercial phase contrast microscope. We use SLIM to image a whole organism springtail Ceratophysella denticulata mounted on a slide. This is the first time, to our knowledge, that an entire organism has been imaged using QPI. We also demonstrate the ability of SLIM to image fine structures in addition to providing quantitative data that cannot be obtained by traditional bright field microscopy. PMID:26334858

Dynamics of solid lubrication as observed by optical microscopy

NASA Technical Reports Server (NTRS)

Sliney, H. E.

1976-01-01

A bench metallograph was converted into a micro contact imager by the addition of a tribometer employing a steel ball in sliding contact with a glass disk. The sliding contact was viewed in real time by means of projection microscope optics. The dynamics of abrasive particles and of solid lubricant particles within the contact were observed in detail. The contact was characterized by a constantly changing pattern of elastic strain with the passage of surface discontinuities and solid particles. Abrasive particles fragmented upon entering the contact, embedded in one surface and scratched the other; in contrast, the solid lubricant particles flowed plastically into thin films. The rheological behavior of the lubricating solids gave every appearance of a paste-like consistency within the Hertzian contact.

Digital Pathology Evaluation in the Multicenter Nephrotic Syndrome Study Network (NEPTUNE)

PubMed Central

Nast, Cynthia C.; Jennette, J. Charles; Hodgin, Jeffrey B.; Herzenberg, Andrew M.; Lemley, Kevin V.; Conway, Catherine M.; Kopp, Jeffrey B.; Kretzler, Matthias; Lienczewski, Christa; Avila-Casado, Carmen; Bagnasco, Serena; Sethi, Sanjeev; Tomaszewski, John; Gasim, Adil H.

2013-01-01

Summary Pathology consensus review for clinical trials and disease classification has historically been performed by manual light microscopy with sequential section review by study pathologists, or multi-headed microscope review. Limitations of this approach include high intra- and inter-reader variability, costs, and delays for slide mailing and consensus reviews. To improve this, the Nephrotic Syndrome Study Network (NEPTUNE) is systematically applying digital pathology review in a multicenter study using renal biopsy whole slide imaging (WSI) for observation-based data collection. Study pathology materials are acquired, scanned, uploaded, and stored in a web-based information system that is accessed through a web-browser interface. Quality control includes metadata and image quality review. Initially, digital slides are annotated, with each glomerulus identified, given a unique number, and maintained in all levels until the glomerulus disappears or sections end. The software allows viewing and annotation of multiple slide sections concurrently. Analysis utilizes “descriptors” for patterns of injury, rather than diagnoses, in renal parenchymal compartments. This multidimensional representation via WSI, allows more accurate glomerular counting and identification of all lesions in each glomerulus, with data available in a searchable database. The use of WSI brings about efficiency critical to pathology review in a clinical trial setting, including independent review by multiple pathologists, improved intraobserver and interobserver reproducibility, efficiencies and risk reduction in slide circulation and mailing, centralized management of data integrity and slide images for current or future studies, and web-based consensus meetings. The overall effect is improved incorporation of pathology review in a budget neutral approach. PMID:23393107

Comparing student understanding of quantum physics when embedding multimodal representations into two different writing formats: Presentation format versus summary report format

NASA Astrophysics Data System (ADS)

Gunel, Murat; Hand, Brian; Gunduz, Sevket

2006-11-01

Physics as a subject for school students requires an understanding and ability to move between different modes of representation for the concepts under review. However, the inability of students to have a multimodal understanding of the concepts is seen as restricting their understandings of the concepts. The aim of this study was to explore the effectiveness of using writing-to-learn strategies that required students to embed multimodal representations of the concepts. In particular, the study compared a presentation format with a summary report format for students learning quantum theory. A pre-post test design was used to compare performances of these two groups across two units. For unit 1, students' scores from groups that completed either a presentation format (PowerPoint presentation) or a summary report format (chapter summary) were compared. No limits were placed on the amount of text or the number of representations used. For unit 2, products of both groups were constructed for an audience of year 10 students. The presentation format group (PowerPoint) was limited to 15 slides, with a maximum of 10 words displayed per slide; a script was written to accompany the presentation. Slides could include graphical and mathematical formulae; however, the text could not. The summary report format group that wrote out its explanations was limited to four pages and was required to incorporate multimodal representations. Results indicated that for both units students using the presentation format group scored significantly better on tests than the summary report format group. The effect size difference between the groups increased for the second unit, indicating that more practice was leading to better student understanding of the physics concepts.

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.

Instructing the Academic Library User: Historical Background and Utilization of Audiovisual Presentations.

ERIC Educational Resources Information Center

Whitmore, Marilyn P.

A brief sketch of the trends in bibliographic instruction from the 30's through the 70's introduces this review of the literature on applications of instructional media in programs for academic library users. Formats discussed include television, programmed instruction, multimedia presentations, and slide/tape presentations. The slide/tape program…

Neural network-based sliding mode control for atmospheric-actuated spacecraft formation using switching strategy

NASA Astrophysics Data System (ADS)

Sun, Ran; Wang, Jihe; Zhang, Dexin; Shao, Xiaowei

2018-02-01

This paper presents an adaptive neural networks-based control method for spacecraft formation with coupled translational and rotational dynamics using only aerodynamic forces. It is assumed that each spacecraft is equipped with several large flat plates. A coupled orbit-attitude dynamic model is considered based on the specific configuration of atmospheric-based actuators. For this model, a neural network-based adaptive sliding mode controller is implemented, accounting for system uncertainties and external perturbations. To avoid invalidation of the neural networks destroying stability of the system, a switching control strategy is proposed which combines an adaptive neural networks controller dominating in its active region and an adaptive sliding mode controller outside the neural active region. An optimal process is developed to determine the control commands for the plates system. The stability of the closed-loop system is proved by a Lyapunov-based method. Comparative results through numerical simulations illustrate the effectiveness of executing attitude control while maintaining the relative motion, and higher control accuracy can be achieved by using the proposed neural-based switching control scheme than using only adaptive sliding mode controller.

[Microscopic extensions of head and neck squamous cell carcinomas: impact for clinical target volume definition].

PubMed

Fleury, B; Thariat, J; Barnoud, R; Buiret, G; Lebreton, F; Bancel, B; Poupart, M; Devouassoux-Shisheboran, M

2014-11-01

To assess microscopic extensions of head and neck squamous cell carcinomas aiming at a proposal for target volumes of radiation therapy. Surgical specimens were prospectively analysed macroscopically and microscopically. Tumour borders were identified per macroscopic visual examination and inked on stained slides. Then microscopic implants (perineural or lymphatic involvement, or in situ carcinomas) were looked for with an optic microscope in the macroscopic healthy tissue surrounding the tumour. The maximal length from tumour border was correlated with the maximal length of macroscopically healthy tissues assessable. Twenty-one specimens were analysed and 12 were locally advanced tumours. Mean and median maximal microscopic extensions were 2.9 and 1.0mm (0-15mm), respectively. The 90th and 95th percentiles were 5 and 11mm, respectively. The ratio between healthy tissue length and maximal microscopic tumour extension was 10%. No correlation was found with tumour grade or volume. The presence of microscopic tumour was unlikely after 5mm from macroscopic tumour (≤5% of patients in this series) but should be assessed along with other histoclinical factors and particularities of tumour behaviour by anatomic site. A rigorous terminology should authorize a relevant appreciation of local risk of recurrence, particularly in adjuvant setting or for clinical target volume definition. Larger and more homogenous confirmatory series are needed. Copyright © 2014. Published by Elsevier SAS.

Rock Slide Risk Assessment: A Semi-Quantitative Approach

NASA Astrophysics Data System (ADS)

Duzgun, H. S. B.

2009-04-01

Rock slides can be better managed by systematic risk assessments. Any risk assessment methodology for rock slides involves identification of rock slide risk components, which are hazard, elements at risk and vulnerability. For a quantitative/semi-quantitative risk assessment for rock slides, a mathematical value the risk has to be computed and evaluated. The quantitative evaluation of risk for rock slides enables comparison of the computed risk with the risk of other natural and/or human-made hazards and providing better decision support and easier communication for the decision makers. A quantitative/semi-quantitative risk assessment procedure involves: Danger Identification, Hazard Assessment, Elements at Risk Identification, Vulnerability Assessment, Risk computation, Risk Evaluation. On the other hand, the steps of this procedure require adaptation of existing or development of new implementation methods depending on the type of landslide, data availability, investigation scale and nature of consequences. In study, a generic semi-quantitative risk assessment (SQRA) procedure for rock slides is proposed. The procedure has five consecutive stages: Data collection and analyses, hazard assessment, analyses of elements at risk and vulnerability and risk assessment. The implementation of the procedure for a single rock slide case is illustrated for a rock slope in Norway. Rock slides from mountain Ramnefjell to lake Loen are considered to be one of the major geohazards in Norway. Lake Loen is located in the inner part of Nordfjord in Western Norway. Ramnefjell Mountain is heavily jointed leading to formation of vertical rock slices with height between 400-450 m and width between 7-10 m. These slices threaten the settlements around Loen Valley and tourists visiting the fjord during summer season, as the released slides have potential of creating tsunami. In the past, several rock slides had been recorded from the Mountain Ramnefjell between 1905 and 1950. Among them, four of the slides caused formation of tsunami waves which washed up to 74 m above the lake level. Two of the slides resulted in many fatalities in the inner part of the Loen Valley as well as great damages. There are three predominant joint structures in Ramnefjell Mountain, which controls failure and the geometry of the slides. The first joint set is a foliation plane striking northeast-southwest and dipping 35˚ -40˚ to the east-southeast. The second and the third joint sets are almost perpendicular and parallel to the mountain side and scarp, respectively. These three joint sets form slices of rock columns with width ranging between 7-10 m and height of 400-450 m. It is stated that the joints in set II are opened between 1-2 m, which may bring about collection of water during heavy rainfall or snow melt causing the slices to be pressed out. It is estimated that water in the vertical joints both reduces the shear strength of sliding plane and causes reduction of normal stress on the sliding plane due to formation of uplift force. Hence rock slides in Ramnefjell mountain occur in plane failure mode. The quantitative evaluation of rock slide risk requires probabilistic analysis of rock slope stability and identification of consequences if the rock slide occurs. In this study failure probability of a rock slice is evaluated by first-order reliability method (FORM). Then in order to use the calculated probability of failure value (Pf) in risk analyses, it is required to associate this Pf with frequency based probabilities (i.ePf / year) since the computed failure probabilities is a measure of hazard and not a measure of risk unless they are associated with the consequences of the failure. This can be done by either considering the time dependent behavior of the basic variables in the probabilistic models or associating the computed Pf with frequency of the failures in the region. In this study, the frequency of previous rock slides in the previous century in Remnefjell is used for evaluation of frequency based probability to be used in risk assessment. The major consequence of a rock slide is generation of a tsunami in the lake Loen, causing inundation of residential areas around the lake. Risk is assessed by adapting damage probability matrix approach, which is originally developed for risk assessment for buildings in case of earthquake.

Evidence for earthquake triggering of large landslides in coastal Oregon, USA

USGS Publications Warehouse

Schulz, W.H.; Galloway, S.L.; Higgins, J.D.

2012-01-01

Landslides are ubiquitous along the Oregon coast. Many are large, deep slides in sedimentary rock and are dormant or active only during the rainy season. Morphology, observed movement rates, and total movement suggest that many are at least several hundreds of years old. The offshore Cascadia subduction zone produces great earthquakes every 300–500 years that generate tsunami that inundate the coast within minutes. Many slides and slide-prone areas underlie tsunami evacuation and emergency response routes. We evaluated the likelihood of existing and future large rockslides being triggered by pore-water pressure increase or earthquake-induced ground motion using field observations and modeling of three typical slides. Monitoring for 2–9 years indicated that the rockslides reactivate when pore pressures exceed readily identifiable levels. Measurements of total movement and observed movement rates suggest that two of the rockslides are 296–336 years old (the third could not be dated). The most recent great Cascadia earthquake was M 9.0 and occurred during January 1700, while regional climatological conditions have been stable for at least the past 600 years. Hence, the estimated ages of the slides support earthquake ground motion as their triggering mechanism. Limit-equilibrium slope-stability modeling suggests that increased pore-water pressures could not trigger formation of the observed slides, even when accompanied by progressive strength loss. Modeling suggests that ground accelerations comparable to those recorded at geologically similar sites during the M 9.0, 11 March 2011 Japan Trench subduction-zone earthquake would trigger formation of the rockslides. Displacement modeling following the Newmark approach suggests that the rockslides would move only centimeters upon coseismic formation; however, coseismic reactivation of existing rockslides would involve meters of displacement. Our findings provide better understanding of the dynamic coastal bluff environment and hazards from future subduction-zone earthquakes.

Research on Synthetic Aperture Radar Processing for the Spaceborne Sliding Spotlight Mode.

PubMed

Shen, Shijian; Nie, Xin; Zhang, Xinggan

2018-02-03

Gaofen-3 (GF-3) is China' first C-band multi-polarization synthetic aperture radar (SAR) satellite, which also provides the sliding spotlight mode for the first time. Sliding-spotlight mode is a novel mode to realize imaging with not only high resolution, but also wide swath. Several key technologies for sliding spotlight mode in spaceborne SAR with high resolution are investigated in this paper, mainly including the imaging parameters, the methods of velocity estimation and ambiguity elimination, and the imaging algorithms. Based on the chosen Convolution BackProjection (CBP) and PFA (Polar Format Algorithm) imaging algorithms, a fast implementation method of CBP and a modified PFA method suitable for sliding spotlight mode are proposed, and the processing flows are derived in detail. Finally, the algorithms are validated by simulations and measured data.

Silvical characteristics of balsam fir (Abies balsamea)

Treesearch

Arthur C. Hart

1959-01-01

Balsam fir takes its name from the Latin word for balm. Some people know the tree as the Balm-of-Gilead fir. It has also been called the blister fir, because of the bark blisters that yield Canada balsam, a resin that is used for, among other things, mounting microscope slides. The needles of balsam fir have a spicy aroma that Donald Culross Peattie has called "...

Nanoroughened plasmonic films for enhanced biosensing detection

NASA Astrophysics Data System (ADS)

LeMoal, Eric; Lévêque-Fort, Sandrine; Potier, Marie-Claude; Fort, Emmanuel

2009-06-01

Although fluorescence is the prevailing labeling technique in biosensing applications, sensitivity improvement is still a striving challenge. We show that coating standard microscope slides with nanoroughened silver films provides a high fluorescence signal enhancement due to plasmonic interactions. As a proof of concept, we applied these films with tailored plasmonic properties to DNA microarrays. Using common optical scanning devices, we achieved signal amplifications of more than 40-fold.

Tunicamycin Enhances Neuroinvasion and Pathogenicity in Mice with Venezuelan Equine Encephalitis Virus

DTIC Science & Technology

2003-01-01

H. Analytical Tests 35 1. Virus Titrations 35 2. RNA Analysis 37 3. Determination of TNF-a and Total Nitrite Levels 37...fluorescent microscope. H. Analytical Tests 1. Virus Titrations For determination of virus titers, brain samples were homogenized in Eppendorf tubes...tissues were mounted on silane-coated slides (Sigma Diagnostics , St. Louis, MO) and labeled for VEE virus antigen by immunohistochemistry. Additional

Bubble-driven light-absorbing hydrogel microrobot for the assembly of bio-objects.

PubMed

Hu, Wenqi; Fan, Qihui; Tonaki, Wade; Ohta, Aaron T

2013-01-01

Microrobots made of light-absorbing hydrogel material were actuated by optically induced thermocapillary flow and move at up to 700 µm/s. The micro-assembly capabilities of the microrobots were demonstrated by assembling polystyrene beads and yeast cells into various patterns on standard glass microscope slides. Two microrobots operating independently in parallel were also used to assemble micro-hydrogel structures.

Mitosis in Barbulanympha. I. Spindle structure, formation, and kinetochore engagement

PubMed Central

1978-01-01

Successful culture of the obligatorily anaerobic symbionts residing in the hindgut of the wood-eating cockroach Cryptocercus punctulatus now permits continuous observation of mitosis in individual Barbulanympha cells. In Part I of this two-part paper, we report methods for culture of the protozoa, preparation of microscope slide cultures in which Barbulanympha survived and divided for up to 3 days, and an optical arrangement which permits observation and through-focus photographic recording of dividing cells, sequentially in differential interference contrast and rectified polarized light microscopy. We describe the following prophase events and structures: development of the astral rays and large extranuclear central spindle from the tips of the elongate-centrioles; the fine structure of spindle fibers and astral rays which were deduced in vivo from polarized light microscopy and seen as a particular array of microtubules in thin-section electron micrographs; formation of chromosomal spindle fibers by dynamic engagement of astral rays to the kinetochores embedded in the persistent nuclear envelope; and repetitive shortening of chromosomal spindle fibers which appear to hoist the nucleus to the spindle surface, cyclically jostle the kinetochores within the nuclear envelope, and churn the prophase chromosomes. The observations described here and in Part II have implications both for the evolution of mitosis and for understanding the mitotic process generally. PMID:681451

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.

Open-source do-it-yourself multi-color fluorescence smartphone microscopy

PubMed Central

Sung, Yulung; Campa, Fernando; Shih, Wei-Chuan

2017-01-01

Fluorescence microscopy is an important technique for cellular and microbiological investigations. Translating this technique onto a smartphone can enable particularly powerful applications such as on-site analysis, on-demand monitoring, and point-of-care diagnostics. Current fluorescence smartphone microscope setups require precise illumination and imaging alignment which altogether limit its broad adoption. We report a multi-color fluorescence smartphone microscope with a single contact lens-like add-on lens and slide-launched total-internal-reflection guided illumination for three common tasks in investigative fluorescence microscopy: autofluorescence, fluorescent stains, and immunofluorescence. The open-source, simple and cost-effective design has the potential for do-it-yourself fluorescence smartphone microscopy. PMID:29188104

Validation of the Sysmex sp-1000i automated slide preparer-stainer in a clinical laboratory

PubMed Central

de Bitencourt, Eberson Damião dos Santos; Voegeli, Carlos Franco; Onzi, Gabriela dos Santos; Boscato, Sara Cardoso; Ghem, Carine; Munhoz, Terezinha

2013-01-01

Background The speed and quality of information have become essential items in the release of laboratory reports. The Sysmex®SP1000-I device has been developed to prepare and stain smear slides. However, for a device to be cleared for use in the laboratory routine it must pass through a validation process. Objective To evaluate the performance and reliability of the Sysmex® SP-1000i slide preparer-stainer incorporated into the routine of a hospital laboratory in Porto Alegre. Methods Peripheral blood samples of patients attending the laboratory for ambulatory exams with leukocyte counts between 7000/°L and 12,000/°L were evaluated, independent of gender and age. Two slides were prepared for each sample using the Sysmex® SP-1000i equipment; one of the slides was used to perform quality control tests using the CellaVision® DM96 device, and the other slide was used to compare pre-classification by the same device and the classification performed by a pharmacist-biochemist. Results The results of all the slides used as controls were acceptable according to the quality control test as established by the manufacturer of the device. In the comparison between the automated pre-classification and the classification made by the professional, there was an acceptable variation in the differential counts of leukocytes for 90% of the analyzed slides. Pearson correlation coefficient showed a strong correlation for band neutrophils (r = 0.802; p-value < 0.001), segmented neutrophils (r = 0.963; p-value < 0.001), eosinophils (r = 0.958; p-value < 0.001), lymphocytes (r = 0.985; p-value < 0.001) and atypical lymphocytes (r = 0.866; p-value < 0.001) using both methods. The red blood cell analysis was adequate for all slides analyzed by the equipment and by the professional. Conclusion The new Sysmex®SP1000-i methodology was found to be reliable, fast and safe for the routines of medium and large laboratories, improving the quality of microscopic analysis in complete blood counts. PMID:24478606

A method of mounting multiple otoliths for beam-based microchemical analyses

USGS Publications Warehouse

Donohoe, C.J.; Zimmerman, C.E.

2010-01-01

Beam-based analytical methods are widely used to measure the concentrations of elements and isotopes in otoliths. These methods usually require that otoliths be individually mounted and prepared to properly expose the desired growth region to the analytical beam. Most analytical instruments, such as LA-ICPMS and ion and electron microprobes, have sample holders that will accept only one to six slides or mounts at a time. We describe a method of mounting otoliths that allows for easy transfer of many otoliths to a single mount after they have been prepared. Such an approach increases the number of otoliths that can be analyzed in a single session by reducing the need open the sample chamber to exchange slides-a particularly time consuming step on instruments that operate under vacuum. For ion and electron microprobes, the method also greatly reduces the number of slides that must be coated with an electrical conductor prior to analysis. In this method, a narrow strip of cover glass is first glued at one end to a standard microscope slide. The otolith is then mounted in thermoplastic resin on the opposite, free end of the strip. The otolith can then be ground and flipped, if needed, by reheating the mounting medium. After otolith preparation is complete, the cover glass is cut with a scribe to free the otolith and up to 20 small otoliths can be arranged on a single petrographic slide. ?? 2010 The Author(s).

Mobile microscopy as a screening tool for oral cancer in India: A pilot study.

PubMed

Skandarajah, Arunan; Sunny, Sumsum P; Gurpur, Praveen; Reber, Clay D; D'Ambrosio, Michael V; Raghavan, Nisheena; James, Bonney Lee; Ramanjinappa, Ravindra D; Suresh, Amritha; Kandasarma, Uma; Birur, Praveen; Kumar, Vinay V; Galmeanu, Honorius-Cezar; Itu, Alexandru Mihail; Modiga-Arsu, Mihai; Rausch, Saskia; Sramek, Maria; Kollegal, Manohar; Paladini, Gianluca; Kuriakose, Moni; Ladic, Lance; Koch, Felix; Fletcher, Daniel

2017-01-01

Oral cancer is the most common type of cancer among men in India and other countries in South Asia. Late diagnosis contributes significantly to this mortality, highlighting the need for effective and specific point-of-care diagnostic tools. The same regions with high prevalence of oral cancer have seen extensive growth in mobile phone infrastructure, which enables widespread access to telemedicine services. In this work, we describe the evaluation of an automated tablet-based mobile microscope as an adjunct for telemedicine-based oral cancer screening in India. Brush biopsy, a minimally invasive sampling technique was combined with a simplified staining protocol and a tablet-based mobile microscope to facilitate local collection of digital images and remote evaluation of the images by clinicians. The tablet-based mobile microscope (CellScope device) combines an iPad Mini with collection optics, LED illumination and Bluetooth-controlled motors to scan a slide specimen and capture high-resolution images of stained brush biopsy samples. Researchers at the Mazumdar Shaw Medical Foundation (MSMF) in Bangalore, India used the instrument to collect and send randomly selected images of each slide for telepathology review. Evaluation of the concordance between gold standard histology, conventional microscopy cytology, and remote pathologist review of the images was performed as part of a pilot study of mobile microscopy as a screening tool for oral cancer. Results indicated that the instrument successfully collected images of sufficient quality to enable remote diagnoses that show concordance with existing techniques. Further studies will evaluate the effectiveness of oral cancer screening with mobile microscopy by minimally trained technicians in low-resource settings.

A scanning tunneling microscope capable of imaging specified micron-scale small samples.

PubMed

Tao, Wei; Cao, Yufei; Wang, Huafeng; Wang, Kaiyou; Lu, Qingyou

2012-12-01

We present a home-built scanning tunneling microscope (STM) which allows us to precisely position the tip on any specified small sample or sample feature of micron scale. The core structure is a stand-alone soft junction mechanical loop (SJML), in which a small piezoelectric tube scanner is mounted on a sliding piece and a "U"-like soft spring strip has its one end fixed to the sliding piece and its opposite end holding the tip pointing to the sample on the scanner. Here, the tip can be precisely aligned to a specified small sample of micron scale by adjusting the position of the spring-clamped sample on the scanner in the field of view of an optical microscope. The aligned SJML can be transferred to a piezoelectric inertial motor for coarse approach, during which the U-spring is pushed towards the sample, causing the tip to approach the pre-aligned small sample. We have successfully approached a hand cut tip that was made from 0.1 mm thin Pt∕Ir wire to an isolated individual 32.5 × 32.5 μm(2) graphite flake. Good atomic resolution images and high quality tunneling current spectra for that specified tiny flake are obtained in ambient conditions with high repeatability within one month showing high and long term stability of the new STM structure. In addition, frequency spectra of the tunneling current signals do not show outstanding tip mount related resonant frequency (low frequency), which further confirms the stability of the STM structure.

A new ball-on-disk vacuum tribometer with in situ measurement of the wear track by digital holographic microscopy

NASA Astrophysics Data System (ADS)

Meylan, B.; Ciani, D.; Zhang, B.; Cuche, E.; Wasmer, K.

2017-12-01

This contribution presents a new ball-on-disk vacuum tribometer with in situ measurement of the wear track by digital holographic microscopy. This new tribometer allows observation of the evolution of the wear track in situ and in real-time. The method combines a high vacuum high temperature ball-on-disk tribometer with a digital holographic microscope (DHM). The machine was tested and validated by taking DHM images during wear tests at room temperature and in vacuum at 2 · 10-6 of polished 100Cr6 steel disks. We demonstrated that the DHM system is well suited to monitor the evolution of the wear track during sliding. We found that, with an acquisition time of 0.1 ms for the DHM, the maximal linear speed is 10 cm s-1 to have reliable images. We proved, via scanning electron microscope (SEM) pictures, that the lines in the sliding direction in all DHM images exist. We also validated the new tribometer by having an excellent correlation between the images and profiles of the wear track taken by the DHM with the ones from a confocal microscope. Finally, the new tribometer combined with the DHM has four advantages. It can test under vacuum and various atmospheric conditions. The evolution of the wear track is measured in situ and in real-time. Hence, the problem of replacing the sample is avoided. Thanks to the DHM technology, the vertical accuracy of the topographical measurement is 4 nm.

Friction and Wear Behavior of Plasma-Sprayed Al2O3-13 wt.%TiO2 Coatings Under the Lubrication of Liquid Paraffin

NASA Astrophysics Data System (ADS)

Zhao, Xiaoqin; An, Yulong; Hou, Guoliang; Zhou, Huidi; Chen, Jianmin

2014-04-01

Two types of ceramic composite coatings (denoted as N-AT13 coating and M-AT13 coating) were fabricated on 1Cr18Ni9Ti stainless steel substrate from ultra-fine and coarse Al2O3-13%TiO2 feedstocks by air plasma spraying. The friction and wear behavior of as-prepared coatings sliding against Al2O3 and stainless steel balls under the lubrication of liquid paraffin was evaluated with an SRV friction and wear tester (Optimol, Germany). The fractured and worn surfaces of the coatings were observed using a scanning electron microscope and a field-emission scanning electron microscope; and the wear mechanisms of the coatings were discussed based on scanning electron microscopic analysis and energy dispersive spectrometric analysis. Results show that N-AT13 coating possesses a unique microstructure and strong inter-splat bonding, thereby showing increased microhardness and bonding strength as well as much better friction-reduction and wear resistance than M-AT13 coating. Moreover, there exist differences in the wear mechanisms of N-AT13 and M-AT13 coatings which slide against ceramic and stainless steel balls under the lubrication of liquid paraffin. Namely, with the increase of normal load, the burnishing of N-AT13 coating coupled with Al2O3 ball is gradually transformed to grain-abrasion and deformation, while M-AT13 coating is dominated by grain-pullout and brittle fracture in the whole range of tested normal load.

Liquification and soft-sediment deformation in a limestone megabreccia: The Ayabacas giant collapse, Cretaceous, southern Peru

NASA Astrophysics Data System (ADS)

Callot, Pierre; Odonne, Francis; Sempere, Thierry

2008-12-01

In the back-arc basin of southern Peru, the bulk of the mid-Cretaceous carbonate platform collapsed near the Turonian-Coniacian boundary (~ 90-89 Ma), due to slope creation and resulting oversteepening. The resulting mass-wasting deposits, namely the Ayabacas Formation, consist of a megabreccia which is organised from NE to SW in relation with two major fault systems. Facies of sediment reworking (such as brecciation, liquification, sedimentary dykes and soft-sediment deformation) are described and four types of resedimentation facies are define. In the northeastern part of the study area, deposits mainly consist of a mixture of very heterometric clasts and blocks (millimetric to kilometric in size), mainly carbonate but also sandy-marly in nature, floating in sandy-marly matrix that exhibits features of liquification (sedimentary dykes and flows) and plastic deformation. Here, resedimentation facies are characterized by deformations and a brecciated facies at each observation scale (from aerial photographs to thin sections) and are therefore defined as fractal or multi-scale breccias. Some clasts and large amounts of the matrix were derived from the underlying clay-rich sandstones of the Murco Formation. These materials were prone to liquification and plastic deformation, allowing them to act as a sliding sole that facilitated the slides and the downslope movement of large limestone rafts. In the southwestern part of the study area, only limestone breccias are observed, in alternation with well-stratified levels. The sliding sole of plastically deformable siliciclastic sediments that previously acted as a lubricating layer was not present here, as materials were more deeply buried. Variations in the degree of sediment lithification from northeast to southwest are inferred to have existed before the collapse and also within the sedimentary succession in the northeastern part. In particular, limestones were well-cemented at the base of the carbonate succession and formed a cap that prevented water to escape from the underlying siliciclastic materials. Such a succession allowed the formation of limestone clasts and of a slide sole constituted by water-saturated siliciclastic materials. In the southern part of the study area, the slide surface was located within the Murco Formation in the upper part of the collapse and just above the Murco Formation downslope. The collapse was frontally confined as it was blocked downslope by a topographic high that folded the whole limestone succession. In the northern part of the study area, the slide surface was also within the Murco Formation in the upper part, but occurs within the limestone succession downslope, due to higher subsidence that buried the sediments more deeply. The compressional structures affecting the limestone succession in the south are not observed there, suggesting that the toe of the collapse was not blocked here.

Atomistic Simulation of Single Asperity Contact

NASA Astrophysics Data System (ADS)

Philip; Kromer; Marder, Michael

2003-03-01

In the standard (Bowden and Tabor) model of friction, the macroscopic behavior of sliding results from the deformation of microscopic asperities in contact. A recent idea instead extracts macroscopic friction from the aggregate behavior of traveling, self-healing interfacial cracks: certain families of cracks are found to be mathematically forbidden, and the envelope of allowed cracks dictates the familiar Coulomb law of friction. To explore the connection between the new and traditional pictures of friction, we conducted molecular dynamics (MD) simulations of single-asperity contact subjected to an oscillatory sliding force -- a geometry important for the problem of fretting (damage due to small-scale vibratory contact). Our simulations reveal the importance of traveling interface cracks to the dynamics of slip at the interface, and illuminate the dynamics of crack initiation and suppression.

The high-speed sliding friction of graphene and novel routes to persistent superlubricity

PubMed Central

Liu, Yilun; Grey, François; Zheng, Quanshui

2014-01-01

Recent experiments on microscopic graphite mesas demonstrate reproducible high-speed microscale superlubricity, even under ambient conditions. Here, we explore the same phenomenon on the nanoscale, by studying a graphene flake sliding on a graphite substrate, using molecular dynamics. We show that superlubricity is punctuated by high-friction transients as the flake rotates through successive crystallographic alignments with the substrate. Further, we introduce two novel routes to suppress frictional scattering and achieve persistent superlubricity. We use graphitic nanoribbons to eliminate frictional scattering by constraining the flake rotation, an approach we call frictional waveguides. We can also effectively suppress frictional scattering by biaxial stretching of the graphitic substrate. These new routes to persistent superlubricity at the nanoscale may guide the design of ultra-low dissipation nanomechanical devices. PMID:24786521

Textural pattern classification for oral squamous cell carcinoma.

PubMed

Rahman, T Y; Mahanta, L B; Chakraborty, C; DAS, A K; Sarma, J D

2018-01-01

Despite being an area of cancer with highest worldwide incidence, oral cancer yet remains to be widely researched. Studies on computer-aided analysis of pathological slides of oral cancer contribute a lot to the diagnosis and treatment of the disease. Some researches in this direction have been carried out on oral submucous fibrosis. In this work an approach for analysing abnormality based on textural features present in squamous cell carcinoma histological slides have been considered. Histogram and grey-level co-occurrence matrix approaches for extraction of textural features from biopsy images with normal and malignant cells are used here. Further, we have used linear support vector machine classifier for automated diagnosis of the oral cancer, which gives 100% accuracy. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

A comparative study on omnidirectional anti-reflection SiO2 nanostructure films coating by glancing angle deposition

NASA Astrophysics Data System (ADS)

Prachachet, R.; Samransuksamer, B.; Horprathum, M.; Eiamchai, P.; Limwichean, S.; Chananonnawathorn, C.; Lertvanithphol, T.; Muthitamongkol, P.; Boonruang, S.; Buranasiri, P.

2018-02-01

Fabricated omnidirectional anti-reflection nanostructure films as a one of the promising alternative solar cell applications have attracted enormous scientific and industrial research benefits to their broadband, effective over a wide range of incident angles, lithography-free and high-throughput process. Recently, the nanostructure SiO2 film was the most inclusive study on anti-reflection with omnidirectional and broadband characteristics. In this work, the three-dimensional silicon dioxide (SiO2) nanostructured thin film with different morphologies including vertical align, slant, spiral and thin films were fabricated by electron beam evaporation with glancing angle deposition (GLAD) on the glass slide and silicon wafer substrate. The morphological of the prepared samples were characterized by field-emission scanning electron microscope (FE-SEM) and high-resolution transmission electron microscope (HRTEM). The transmission, omnidirectional and birefringence property of the nanostructure SiO2 films were investigated by UV-Vis-NIR spectrophotometer and variable angle spectroscopic ellipsometer (VASE). The spectrophotometer measurement was performed at normal incident angle and a full spectral range of 200 - 2000 nm. The angle dependent transmission measurements were investigated by rotating the specimen, with incidence angle defined relative to the surface normal of the prepared samples. This study demonstrates that the obtained SiO2 nanostructure film coated on glass slide substrate exhibits a higher transmission was 93% at normal incident angle. In addition, transmission measurement in visible wavelength and wide incident angles -80 to 80 were increased in comparison with the SiO2 thin film and glass slide substrate due to the transition in the refractive index profile from air to the nanostructure layer that improve the antireflection characteristics. The results clearly showed the enhanced omnidirectional and broadband characteristic of the three dimensional SiO2 nanostructure film coating.

Dynamic-robotic telepathology: Department of Veterans Affairs feasibility study.

PubMed

Dunn, B E; Almagro, U A; Choi, H; Sheth, N K; Arnold, J S; Recla, D L; Krupinski, E A; Graham, A R; Weinstein, R S

1997-01-01

In this retrospective study, we assess the accuracy, confidence levels, and viewing times of two generalist pathologists using both dynamic-robotic telepathology and conventional light microscopy (LM) to render diagnoses on a test set of 100 consecutive routine surgical pathology cases. The objective is to determine whether telepathology will allow a pathology group practice at a diagnostic hub to provide routine diagnostic services to a remote hospital without an on-site pathologist. For TP, glass slides were placed on the motorized stage of the robotic microscope of a telepathology system by a senior laboratory technologist in Iron Mountain, MI. Real-time control of the motorized microscope was then transferred to a pathologist in Milwaukee, WI, who viewed images of the glass slides on a video monitor. The telepathologists deferred rendering a diagnosis in 1.5% of cases. Clinically important concordance between the individual diagnoses rendered by telepathology and the "truth" diagnoses established by rereview of glass slides was 98.5%. In the telepathology mode, there were five incorrect diagnoses out of a total of 197 diagnoses. In four cases in which the telepathology diagnosis was incorrect, the pathologist's diagnosis by LM was identical to that rendered by telepathology. These represent errors of interpretation and cannot be ascribed to telepathology. The certainty of the pathologists with respect to their diagnoses was evaluated over time. Results for the first 50 cases served as baseline data. For the second 50 cases, confidence in rendering a diagnosis in the telepathology mode was essentially identical to that of making a diagnosis in the LM viewing mode. Viewing times in the telepathology mode also improved with more experience using the telepathology system. These results support the concept that an off-site pathologist using dynamic-robotic telepathology can substitute for an on-site pathologist as a service provider.

Laser capture microdissection of embryonic cells and preparation of RNA for microarray assays.

PubMed

Redmond, Latasha C; Pang, Christopher J; Dumur, Catherine; Haar, Jack L; Lloyd, Joyce A

2014-01-01

In order to compare the global gene expression profiles of different embryonic cell types, it is first necessary to isolate the specific cells of interest. The purpose of this chapter is to provide a step-by-step protocol to perform laser capture microdissection (LCM) on embryo samples and obtain sufficient amounts of high-quality RNA for microarray hybridizations. Using the LCM/microarray strategy on mouse embryo samples has some challenges, because the cells of interest are available in limited quantities. The first step in the protocol is to obtain embryonic tissue, and immediately cryoprotect and freeze it in a cryomold containing Optimal Cutting Temperature freezing media (Sakura Finetek), using a dry ice-isopentane bath. The tissue is then cryosectioned, and the microscope slides are processed to fix, stain, and dehydrate the cells. LCM is employed to isolate specific cell types from the slides, identified under the microscope by virtue of their morphology. Detailed protocols are provided for using the currently available ArcturusXT LCM instrument and CapSure(®) LCM Caps, to which the selected cells adhere upon laser capture. To maintain RNA integrity, upon removing a slide from the final processing step, or attaching the first cells on the LCM cap, LCM is completed within 20 min. The cells are then immediately recovered from the LCM cap using a denaturing solution that stabilizes RNA integrity. RNA is prepared using standard methods, modified for working with small samples. To ensure the validity of the microarray data, the quality of the RNA is assessed using the Agilent bioanalyzer. Only RNA that is of sufficient integrity and quantity is used to perform microarray assays. This chapter provides guidance regarding troubleshooting and optimization to obtain high-quality RNA from cells of limited availability, obtained from embryo samples by LCM.

Static and sliding contact of rough surfaces: Effect of asperity-scale properties and long-range elastic interactions

NASA Astrophysics Data System (ADS)

Hulikal, Srivatsan; Lapusta, Nadia; Bhattacharya, Kaushik

2018-07-01

Friction in static and sliding contact of rough surfaces is important in numerous physical phenomena. We seek to understand macroscopically observed static and sliding contact behavior as the collective response of a large number of microscopic asperities. To that end, we build on Hulikal et al. (2015) and develop an efficient numerical framework that can be used to investigate how the macroscopic response of multiple frictional contacts depends on long-range elastic interactions, different constitutive assumptions about the deforming contacts and their local shear resistance, and surface roughness. We approximate the contact between two rough surfaces as that between a regular array of discrete deformable elements attached to a elastic block and a rigid rough surface. The deformable elements are viscoelastic or elasto/viscoplastic with a range of relaxation times, and the elastic interaction between contacts is long-range. We find that the model reproduces the main macroscopic features of evolution of contact and friction for a range of constitutive models of the elements, suggesting that macroscopic frictional response is robust with respect to the microscopic behavior. Viscoelasticity/viscoplasticity contributes to the increase of friction with contact time and leads to a subtle history dependence. Interestingly, long-range elastic interactions only change the results quantitatively compared to the meanfield response. The developed numerical framework can be used to study how specific observed macroscopic behavior depends on the microscale assumptions. For example, we find that sustained increase in the static friction coefficient during long hold times suggests viscoelastic response of the underlying material with multiple relaxation time scales. We also find that the experimentally observed proportionality of the direct effect in velocity jump experiments to the logarithm of the velocity jump points to a complex material-dependent shear resistance at the microscale.

Laser Capture Microdissection of Embryonic Cells and Preparation of RNA for Microarray Assays

PubMed Central

Redmond, Latasha C.; Pang, Christopher J.; Dumur, Catherine; Haar, Jack L.; Lloyd, Joyce A.

2014-01-01

In order to compare the global gene expression profiles of different embryonic cell types, it is first necessary to isolate the specific cells of interest. The purpose of this chapter is to provide a step-by-step protocol to perform laser capture microdissection (LCM) on embryo samples and obtain sufficient amounts of high-quality RNA for microarray hybridizations. Using the LCM/microarray strategy on mouse embryo samples has some challenges, because the cells of interest are available in limited quantities. The first step in the protocol is to obtain embryonic tissue, and immediately cryoprotect and freeze it in a cryomold containing Optimal Cutting Temperature freezing media (Sakura Finetek), using a dry ice–isopentane bath. The tissue is then cryosectioned, and the microscope slides are processed to fix, stain, and dehydrate the cells. LCM is employed to isolate specific cell types from the slides, identified under the microscope by virtue of their morphology. Detailed protocols are provided for using the currently available ArcturusXT LCM instrument and CapSure® LCM Caps, to which the selected cells adhere upon laser capture. To maintain RNA integrity, upon removing a slide from the final processing step, or attaching the first cells on the LCM cap, LCM is completed within 20 min. The cells are then immediately recovered from the LCM cap using a denaturing solution that stabilizes RNA integrity. RNA is prepared using standard methods, modified for working with small samples. To ensure the validity of the microarray data, the quality of the RNA is assessed using the Agilent bioanalyzer. Only RNA that is of sufficient integrity and quantity is used to perform microarray assays. This chapter provides guidance regarding troubleshooting and optimization to obtain high-quality RNA from cells of limited availability, obtained from embryo samples by LCM. PMID:24318813

Diagnosis and identification of Leishmania spp. from Giemsa-stained slides, by real-time PCR and melting curve analysis in south-west of Iran.

PubMed

Khademvatan, S; Neisi, N; Maraghi, S; Saki, J

2011-12-01

The aim of present study was describing a real-time PCR assay for the diagnosis and direct identification of Leishmania species on Giemsa-stained slides in south-west of Iran. Altogether, 102 Giemsa-stained slides were collected from different part of south-west of Iran between 2008 and 2011. All the Giemsa-stained slides were examined under light microscope. After DNA extraction, real-time PCR amplification and detection were conducted with fluorescent SYBR Green I. For identification, PCR products were analysed with melting curve analysis. One hundred and two archived slides from suspected lesion examined by microscopy and real-time PCR. The sensitivity of the real-time PCR on Giemsa-stained slid was 98% (96/102). The melting curve analysis (T(m)) were 88·3±0·2°C for L. tropica (MHOM/IR/02/Mash10), 86·5±0·2°C for L. major (MHOM/IR/75/ER) and 89·4±0·3°C for L. infantum (MCAN/IR/97/LON 49), respectively. This study is first report in use of real-time PCR for diagnosis and identification of Leishmania spp. in Iran. Up to now, in Iran, the majority of identification of Leishmania species is restriction fragment length polymorphism (PCR-RFLP) of ITS1 and kinetoplast DNA. Our data showed that Giemsa-stained slides that were stored more than 3 years, can be use for Leishmania DNA extraction and amplification by real-time PCR. Compared to conventional PCR-based methods, the real-time PCR is extremely rapid with results and more samples can be processed at one time.

Web-based oil immersion whole slide imaging increases efficiency and clinical team satisfaction in hematopathology tumor board

PubMed Central

Chen, Zhongchuan Will; Kohan, Jessica; Perkins, Sherrie L.; Hussong, Jerry W.; Salama, Mohamed E.

2014-01-01

Background: Whole slide imaging (WSI) is widely used for education and research, but is increasingly being used to streamline clinical workflow. We present our experience with regard to satisfaction and time utilization using oil immersion WSI for presentation of blood/marrow aspirate smears, core biopsies, and tissue sections in hematology/oncology tumor board/treatment planning conferences (TPC). Methods: Lymph nodes and bone marrow core biopsies were scanned at ×20 magnification and blood/marrow smears at 83X under oil immersion and uploaded to an online library with areas of interest to be displayed annotated digitally via web browser. Pathologist time required to prepare slides for scanning was compared to that required to prepare for microscope projection (MP). Time required to present cases during TPC was also compared. A 10-point evaluation survey was used to assess clinician satisfaction with each presentation method. Results: There was no significant difference in hematopathologist preparation time between WSI and MP. However, presentation time was significantly less for WSI compared to MP as selection and annotation of slides was done prior to TPC with WSI, enabling more efficient use of TPC presentation time. Survey results showed a significant increase in satisfaction by clinical attendees with regard to image quality, efficiency of presentation of pertinent findings, aid in clinical decision-making, and overall satisfaction regarding pathology presentation. A majority of respondents also noted decreased motion sickness with WSI. Conclusions: Whole slide imaging, particularly with the ability to use oil scanning, provides higher quality images compared to MP and significantly increases clinician satisfaction. WSI streamlines preparation for TPC by permitting prior slide selection, resulting in greater efficiency during TPC presentation. PMID:25379347

Seasonal ocean upwelling recorded by the late Miocene Pisco Formation diatomites of Peru

NASA Astrophysics Data System (ADS)

Gariboldi, Karen; Pike, Jennifer; Di Celma, Claudio; Malinverno, Elisa; Gioncada, Anna; Bianucci, Giovanni

2017-04-01

A 25-cm-thick sample of diatomaceous mudstone was collected in the whale fossil-bearing late Miocene Pisco Formation at Cerro Los Quesos in Peru. This macroscopically-laminated sample was divided into blocks and embedded in epoxy resin for light and scanning electron microscope (SEM) analysis. In only a few cases are laminae well preserved and, hence, useful for paleoenvironmental studies. In these few cases, a terrigenous lamina - Coscinodiscus ooze lamina - mixed lamina (Chaetoceros resting spores, Thalassionema, terrigenous material) sequence is observed. By comparison with Holocene sediment laminations from the Gulf of California, the late Miocene Peruvian triplet laminations are interpreted as an annual depositional cycle. The terrigenous lamina was deposited in the wet season (summer). Coscinodiscus ooze was the product of: (1) initial high summer primary production which took place at the thermocline during water column stratification; and (2) a subsequent 'Fall dump', or sedimentation, of the diatoms due to autumn storm-related mixing of the water column. Finally, the mixed lamina was deposited during/following the spring bloom. The frequent disruption or homogenisation of laminae observed in the slides was attributed to bioturbation by microbenthic organisms. This bioturbation was accompanied by a general absence of macrobenthos in the late Miocene diatomites of the Pisco Formation; such conditions are commonly interpreted as the consequence of a suboxic sea floor environment. In this presentation we will demonstrate the seasonal nature of the Late Miocene Pisco Formation diatomites and show novel SEM microelemental maps that help interpreting the paleonvironmental conditions at the sea floor at the time of diatomites deposition.

Comparison of LED and Conventional Fluorescence Microscopy for Detection of Acid Fast Bacilli in a Low-Incidence Setting

PubMed Central

Minion, Jessica; Pai, Madhukar; Ramsay, Andrew; Menzies, Dick; Greenaway, Christina

2011-01-01

Introduction Light emitting diode fluorescence microscopes have many practical advantages over conventional mercury vapour fluorescence microscopes, which would make them the preferred choice for laboratories in both low- and high-resource settings, provided performance is equivalent. Methods In a nested case-control study, we compared diagnostic accuracy and time required to read slides with the Zeiss PrimoStar iLED, LW Scientific Lumin, and a conventional fluorescence microscope (Leica DMLS). Mycobacterial culture was used as the reference standard, and subgroup analysis by specimen source and organism isolated were performed. Results There was no difference in sensitivity or specificity between the three microscopes, and agreement was high for all comparisons and subgroups. The Lumin and the conventional fluorescence microscope were equivalent with respect to time required to read smears, but the Zeiss iLED was significantly time saving compared to both. Conclusions Light emitting diode microscopy should be considered by all tuberculosis diagnostic laboratories, including those in high income countries, as a replacement for conventional fluorescence microscopes. Our findings provide support to the recent World Health Organization policy recommending that conventional fluorescence microscopy be replaced by light emitting diode microscopy using auramine staining in all settings where fluorescence microscopy is currently used. PMID:21811622

Microbial structures in an Alpine Thermal Spring - Microscopic techniques for the examination of Biofilms in a Subsurface Environment

NASA Astrophysics Data System (ADS)

Dornmayr-Pfaffenhuemer, Marion; Pierson, Elisabeth; Janssen, Geert-Jan; Stan-Lotter, Helga

2010-05-01

The research into extreme environments hast important implications for biology and other sciences. Many of the organisms found there provide insights into the history of Earth. Life exists in all niches where water is present in liquid form. Isolated environments such as caves and other subsurface locations are of interest for geomicrobiological studies. And because of their "extra-terrestrial" conditions such as darkness and mostly extreme physicochemical state they are also of astrobiological interest. The slightly radioactive thermal spring at Bad Gastein (Austria) was therefore examined for the occurrence of subsurface microbial communities. The surfaces of the submerged rocks in this warm spring were overgrown by microbial mats. Scanning electron microscopy (SEM) performed by the late Dr. Wolfgang Heinen revealed an interesting morphological diversity in biofilms found in this environment (1, 2). Molecular analysis of the community structure of the radioactive subsurface thermal spring was performed by Weidler et al. (3). The growth of these mats was simulated using sterile glass slides which were exposed to the water stream of the spring. Those mats were analysed microscopically. Staining, using fluorescent dyes such as 4',6-Diamidino-2-phenylindol (DAPI), gave an overview of the microbial diversity of these biofilms. Additional SEM samples were prepared using different fixation protocols. Scanning confocal laser microscopy (SCLM) allowed a three dimensional view of the analysed biofilms. This work presents some electron micrographs of Dr. Heinen and additionally new microscopic studies of the biofilms formed on the glass slides. The appearances of the new SEM micrographs were compared to those of Dr. Heinen that were done several years ago. The morphology and small-scale distribution in the microbial mat was analyzed by fluorescence microscopy. The examination of natural biomats and biofilms grown on glass slides using several microscopical techniques suggest that the thermal springs in the Central Alps near Bad Gastein represent a novel and unique habitat for microbial life. Results obtained during these studies revealed reproducibility of Dr. Heinen's micrographs. Hollow reticulated filaments and flat ribbons with parallel hexagonal chambers (web-structures) were found repeatedly. Given the chance that subsurface environments represent a potent opportunity to detect life on planetary bodies it is of big interest to search for representative biosignatures found on earth today. References: 1. Lauwers A. M. & Heinen W. (1985) Mikroskopie (Wien) 42, 94-101. 2. Heinen W. & Lauwers A. M. (1985) Mikroskopie (Wien) 42, 124-134. 3. Weidler G. W., Dornmayr-Pfaffenhuemer M., Gerbl F. W., Heinen W., Stan-Lotter H. (2007) AEM 73, 259-270.

Radiation Dosimetry via Automated Fluorescence Microscopy

NASA Technical Reports Server (NTRS)

Castleman, Kenneth R.; Schulze, Mark

2005-01-01

A developmental instrument for assessment of radiation-induced damage in human lymphocytes includes an automated fluorescence microscope equipped with a one or more chargecoupled- device (CCD) video camera(s) and circuitry to digitize the video output. The microscope is also equipped with a three-axis translation stage that includes a rotation stage, and a rotary tray that holds as many as thirty specimen slides. The figure depicts one version of the instrument. Once the slides have been prepared and loaded into the tray, the instrument can operate unattended. A computer controls the operation of the stage, tray, and microscope, and processes the digital fluorescence-image data to recognize and count chromosomes that have been broken, presumably by radiation. The design and method of operation of the instrument exploit fluorescence in situ hybridization (FISH) of metaphase chromosome spreads, which is a technique that has been found to be valuable for monitoring the radiation dose to circulating lymphocytes. In the specific FISH protocol used to prepare specimens for this instrument, metaphase lymphocyte cultures are chosen for high mitotic index and highly condensed chromosomes, then several of the largest chromosomes are labeled with three of four differently colored whole-chromosome-staining dyes. The three dyes, which are used both individually and in various combinations, are fluorescein isothiocyanate (FITC), Texas Red (or equivalent), and Cy5 (or equivalent); The fourth dye 4',6-diamidino- 2-phenylindole (DAPI) is used as a counterstain. Under control by the computer, the microscope is automatically focused on the cells and each slide is scanned while the computer analyzes the DAPI-fluorescence images to find the metaphases. Each metaphase field is recentered in the field of view and refocused. Then a four-color image (more precisely, a set of images of the same view in the fluorescent colors of the four dyes) is acquired. By use of pattern-recognition software developed specifically for this instrument, the images in the various colors are processed to recognize the metaphases and count the chromosome fragments of each color within the metaphases. The intermediate results are then further processed to estimate the proportion of cells that have suffered genetic damage. The prototype instrument scans at an average areal rate of 4.7 mm2/h in unattended operation, finding about 14 metaphases per hour. The false-alarm rate is typically less than 3 percent, and the metaphase-miss rate has been estimated to be less than 5 percent. The counts of chromosomes and fragments thereof are 50 to 70 percent accurate.

Accessible microscopy workstation for students and scientists with mobility impairments.

PubMed

Duerstock, Bradley S

2006-01-01

An integrated accessible microscopy workstation was designed and developed to allow persons with mobility impairments to control all aspects of light microscopy with minimal human assistance. This system, named AccessScope, is capable of performing brightfield and fluorescence microscopy, image analysis, and tissue morphometry requisite for undergraduate science courses to graduate-level research. An accessible microscope is necessary for students and scientists with mobility impairments to be able to use a microscope independently to better understand microscopical imaging concepts and cell biology. This knowledge is not always apparent by simply viewing a catalog of histological images. The ability to operate a microscope independently eliminates the need to hire an assistant or rely on a classmate and permits one to take practical laboratory examinations by oneself. Independent microscope handling is also crucial for graduate students and scientists with disabilities to perform scientific research. By making a personal computer as the user interface for controlling AccessScope functions, different upper limb mobility impairments could be accommodated by using various computer input devices and assistive technology software. Participants with a range of upper limb mobility impairments evaluated the prototype microscopy workstation. They were able to control all microscopy functions including loading different slides without assistance.

Microscopic diagnosis of dysbacteriosis in stained vaginal smears in clinical practice.

PubMed

Verbruggen, Banut-Sabine M; Boon, Mathilde E; Melkerl, Peter; van Haaften, Maarten; Heintz, A Peter M

2006-10-01

Dysbacteriosis is a microscopical diagnosis. In women with dysbacteriosis, an overgrowth of coccoid bacteria and almost a complete absence of lactobacilli are observed in the (stained) vaginal smear. The aim of this study was to determine the accuracy of this microscopic diagnosis in clinical practice. The analysis concerned 342 consecutive cases in which the microscopy of the stained smears was performed by general practitioners trained in diagnosing dysbacteriosis. These smears were sent to the pathologist for confirmation of the microscopical diagnosis of the clinician. The cytological diagnoses of the pathologist, sometimes performed on restained slides when the quality of the staining was substandard, were considered as the "gold standard." In 92 of the 342 cases, dysbacteriosis was unequivocally established by the pathologist. Sensitivity and specificity of the microscopical diagnoses of the clinicians were 40% and 85%, respectively. There were 37 false-positive and 54 false-negative diagnoses of dysbacteriosis rendered by the clinicians. The most frequent reason for a false-negative diagnosis was an excess of lactobacilli in the smear. This study shows that even in stained smears it is difficult for clinicians to render a correct evaluation of the status of the vaginal flora.

Nipple adenoma arising from axillary accessory breast: a case report

PubMed Central

2012-01-01

Nipple adenoma is a relatively rare benign breast neoplasm, and cases of the disease arising from the axillary accessory breast have very seldom been reported in the English literature. We report a case of nipple adenoma arising from axillary accessory breast including clinical and pathological findings. An 82-year-old woman presented with the complaint of a small painful mass in the right axilla. Physical examination confirmed a well-defined eczematous crusted mass that was 8 mm in size. The diagnosis of nipple adenoma was made from an excisional specimen on the basis of characteristic histological findings. Microscopic structural features included a compact proliferation of small tubules lined by epithelial and myoepithelial cells, and the merging of glandular epithelial cells of the adenoma into squamous epithelial cells in the superficial epidermal layer. Because clinically nipple adenoma may resemble Paget’s disease and pathologically can be misinterpreted as tubular carcinoma, the correct identification of nipple adenoma is an important factor in the differential diagnosis for axillary tumor neoplasms. Virtual slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1186821489769063 PMID:23186145

Colour in digital pathology: a review.

PubMed

Clarke, Emily L; Treanor, Darren

2017-01-01

Colour is central to the practice of pathology because of the use of coloured histochemical and immunohistochemical stains to visualize tissue features. Our reliance upon histochemical stains and light microscopy has evolved alongside a wide variation in slide colour, with little investigation into the implications of colour variation. However, the introduction of the digital microscope and whole-slide imaging has highlighted the need for further understanding and control of colour. This is because the digitization process itself introduces further colour variation which may affect diagnosis, and image analysis algorithms often use colour or intensity measures to detect or measure tissue features. The US Food and Drug Administration have released recent guidance stating the need to develop a method of controlling colour reproduction throughout the digitization process in whole-slide imaging for primary diagnostic use. This comprehensive review introduces applied basic colour physics and colour interpretation by the human visual system, before discussing the importance of colour in pathology. The process of colour calibration and its application to pathology are also included, as well as a summary of the current guidelines and recommendations regarding colour in digital pathology. © 2016 John Wiley & Sons Ltd.

Virtual slide telepathology workstation of the future: lessons learned from teleradiology.

PubMed

Krupinski, Elizabeth A

2009-08-01

The clinical reading environment for the 21st century pathologist looks very different than it did even a few short years ago. Glass slides are quickly being replaced by digital "virtual slides," and the traditional light microscope is being replaced by the computer display. There are numerous questions that arise however when deciding exactly what this new digital display viewing environment will be like. Choosing a workstation for daily use in the interpretation of digital pathology images can be a very daunting task. Radiology went digital nearly 20 years ago and faced many of the same challenges so there are lessons to be learned from these experiences. One major lesson is that there is no "one size fits all" workstation so users must consider a variety of factors when choosing a workstation. In this article, we summarize some of the potentially critical elements in a pathology workstation and the characteristics one should be aware of and look for in the selection of one. Issues pertaining to both hardware and software aspects of medical workstations will be reviewed particularly as they may impact the interpretation process.

Wear behavior of electroless Ni-P-W coating under lubricated condition - a Taguchi based approach

NASA Astrophysics Data System (ADS)

Mukhopadhyay, Arkadeb; Duari, Santanu; Barman, Tapan Kumar; Sahoo, Prasanta

2016-09-01

The present study aims to investigate the tribological behavior of electroless Ni-P-W coating under engine oil lubricated condition to ascertain its suitability in automotive applications. Coating is deposited onto mild steel specimens by the electroless method. The experiments are carried out on a pin - on - disc type tribo tester under lubrication. Three tribotesting parameters namely the applied normal load, sliding speed and sliding duration are varied at their three levels and their effects on the wear depth of the deposits are studied. The experiments are carried out based on the combinations available in Taguchi's L27 orthogonal array (OA). Optimization of the tribo-testing parameters is carried out using Taguchi's S/N ratio method to minimize the wear depth. Analysis of variance carried out at a confidence level of 99% indicates that the sliding speed is the most significant parameter in controlling the wear behavior of the deposits. Coating characterization is done using scanning electron microscope, energy dispersive X-ray analysis and X-ray diffraction techniques. It is seen that the wear mechanism under lubricated condition is abrasive in nature.

Pulmonary artery sarcoma with angiosarcoma phenotype mimicking pleomorphic malignant fibrous histiocytoma: a case report

PubMed Central

2012-01-01

Abstract Primary sarcomas of the major blood vessels can be classified based on location in relationship to the wall or by histologic type. Angiosarcomas are malignant neoplasms that arise from the endothelial lining of the blood vessels; those arising in the intimal compartment of pulmonary artery are rare. We report a case of pulmonary artery angiosarcoma in a 36-year old female with pulmonary masses. The patient had no other primary malignant neoplasm, thus excluding a metastatic lesion. Gross examination revealed a thickened right pulmonary artery and a necrotic and hemorrhagic tumor, filling and occluding the vascular lumen. The mass extended distally, within the pulmonary vasculature of the right lung. Microscopically, an intravascular undifferentiated tumor was identified. The tumor cells showed expression for vascular markers VEGFR, VEGFR3, PDGFRa, FGF, Ulex europaeus, FVIII, FLI-1, CD31 and CD34; p53 was overexpressed and Ki67 proliferative rate was increased. Intravascular angiosarcomas are aggressive neoplasms, often associated with poor outcome. Virtual slide The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2315906377648045. PMID:23134683

Markov state modeling of sliding friction

NASA Astrophysics Data System (ADS)

Pellegrini, F.; Landes, François P.; Laio, A.; Prestipino, S.; Tosatti, E.

2016-11-01

Markov state modeling (MSM) has recently emerged as one of the key techniques for the discovery of collective variables and the analysis of rare events in molecular simulations. In particular in biochemistry this approach is successfully exploited to find the metastable states of complex systems and their evolution in thermal equilibrium, including rare events, such as a protein undergoing folding. The physics of sliding friction and its atomistic simulations under external forces constitute a nonequilibrium field where relevant variables are in principle unknown and where a proper theory describing violent and rare events such as stick slip is still lacking. Here we show that MSM can be extended to the study of nonequilibrium phenomena and in particular friction. The approach is benchmarked on the Frenkel-Kontorova model, used here as a test system whose properties are well established. We demonstrate that the method allows the least prejudiced identification of a minimal basis of natural microscopic variables necessary for the description of the forced dynamics of sliding, through their probabilistic evolution. The steps necessary for the application to realistic frictional systems are highlighted.

High quality tissue miniarray technique using a conventional TV/radio telescopic antenna.

PubMed

Elkablawy, Mohamed A; Albasri, Abdulkader M

2015-01-01

The tissue microarray (TMA) is widely accepted as a fast and cost-effective research tool for in situ tissue analysis in modern pathology. However, the current automated and manual TMA techniques have some drawbacks restricting their productivity. Our study aimed to introduce an improved manual tissue miniarray (TmA) technique that is simple and readily applicable to a broad range of tissue samples. In this study, a conventional TV/radio telescopic antenna was used to punch tissue cores manually from donor paraffin embedded tissue blocks which were pre-incubated at 40oC. The cores were manually transferred, organized and attached to a standard block mould, and filled with liquid paraffin to construct TmA blocks without any use of recipient paraffin blocks. By using a conventional TV/radio antenna, it was possible to construct TmA paraffin blocks with variable formats of array size and number (2-mm x 42, 2.5-mm x 30, 3-mm x 24, 4-mm x 20 and 5-mm x 12 cores). Up to 2-mm x 84 cores could be mounted and stained on a standard microscopic slide by cutting two sections from two different blocks and mounting them beside each other. The technique was simple and caused minimal damage to the donor blocks. H and E and immunostained slides showed well-defined tissue morphology and array configuration. This technique is easy to reproduce, quick, inexpensive and creates uniform blocks with abundant tissues without specialized equipment. It was found to improve the stability of the cores within the paraffin block and facilitated no losses during cutting and immunostaining.

Refractive-index profiling of embedded microstructures in optical materials

NASA Astrophysics Data System (ADS)

Dave, Digant P.; Milner, Thomas E.

2002-04-01

We describe use of a phase-sensitive low-coherence reflectometer to measure spatial variation of refractive index in optical materials. The described interferometric technique is demonstrated to be a valuable tool to profile the refractive index of optical elements such as integrated waveguides and photowritten optical microstructures. As an example, a refractive-index profile is mapped of a microstructure written in a microscope glass slide with an ultrashort-pulse laser.

Nonmonotonic velocity dependence of atomic friction.

PubMed

Reimann, Peter; Evstigneev, Mykhaylo

2004-12-03

We propose a theoretical model for friction force microscopy experiments with special emphasis on the realistic description of dissipation and inertia effects. Its main prediction is a nonmonotonic dependence of the friction force upon the sliding velocity of the atomic force microscope tip relative to an atomically flat surface. The region around the force maximum can be approximately described by a universal scaling law and should be observable under experimentally realistic conditions.

Contraction-free, fume-fixed longitudinal sections of fresh frozen muscle

NASA Technical Reports Server (NTRS)

Riley, Danny A.; Slocum, Glenn R.

1988-01-01

Contraction damage occurring when longitudinal frozen sections of fresh unfixed muscles are thawed on microscope slides has limited histological examination of this tissue mainly to cross sections. Longitudinally oriented sections are advantageous for investigating properties that vary along the length of the muscle fibers. A fume fixation technique has been developed for preventing contraction of thick longitudinal frozen sections. The technique is compatible with histochemical staining of enzymes.

18/20 T high magnetic field scanning tunneling microscope with fully low voltage operability, high current resolution, and large scale searching ability.

PubMed

Li, Quanfeng; Wang, Qi; Hou, Yubin; Lu, Qingyou

2012-04-01

We present a home-built 18/20 T high magnetic field scanning tunneling microscope (STM) featuring fully low voltage (lower than ±15 V) operability in low temperatures, large scale searching ability, and 20 fA high current resolution (measured by using a 100 GOhm dummy resistor to replace the tip-sample junction) with a bandwidth of 3.03 kHz. To accomplish low voltage operation which is important in achieving high precision, low noise, and low interference with the strong magnetic field, the coarse approach is implemented with an inertial slider driven by the lateral bending of a piezoelectric scanner tube (PST) whose inner electrode is axially split into two for enhanced bending per volt. The PST can also drive the same sliding piece to inertial slide in the other bending direction (along the sample surface) of the PST, which realizes the large area searching ability. The STM head is housed in a three segment tubular chamber, which is detachable near the STM head for the convenience of sample and tip changes. Atomic resolution images of a graphite sample taken under 17.6 T and 18.0001 T are presented to show its performance. © 2012 American Institute of Physics

A microarray immunoassay for simultaneous detection of proteins and bacteria

NASA Technical Reports Server (NTRS)

Delehanty, James B.; Ligler, Frances S.

2002-01-01

We report the development and characterization of an antibody microarray biosensor for the rapid detection of both protein and bacterial analytes under flow conditions. Using a noncontact microarray printer, biotinylated capture antibodies were immobilized at discrete locations on the surface of an avidin-coated glass microscope slide. Preservation of capture antibody function during the deposition process was accomplished with the use of a low-salt buffer containing sucrose and bovine serum albumin. The slide was fitted with a six-channel flow module that conducted analyte-containing solutions over the array of capture antibody microspots. Detection of bound analyte was subsequently achieved using fluorescent tracer antibodies. The pattern of fluorescent complexes was interrogated using a scanning confocal microscope equipped with a 635-nm laser. This microarray system was employed to detect protein and bacterial analytes both individually and in samples containing mixtures of analytes. Assays were completed in 15 min, and detection of cholera toxin, staphylococcal enterotoxin B, ricin, and Bacillus globigii was demonstrated at levels as low as 8 ng/mL, 4 ng/mL, 10 ng/mL, and 6.2 x 10(4) cfu/mL, respectively. The assays presented here are very fast, as compared to previously published methods for measuring antibody-antigen interactions using microarrays (minutes versus hours).

On the debris-level origins of adhesive wear

NASA Astrophysics Data System (ADS)

Aghababaei, Ramin; Warner, Derek H.; Molinari, Jean-François

2017-07-01

Every contacting surface inevitably experiences wear. Predicting the exact amount of material loss due to wear relies on empirical data and cannot be obtained from any physical model. Here, we analyze and quantify wear at the most fundamental level, i.e., wear debris particles. Our simulations show that the asperity junction size dictates the debris volume, revealing the origins of the long-standing hypothesized correlation between the wear volume and the real contact area. No correlation, however, is found between the debris volume and the normal applied force at the debris level. Alternatively, we show that the junction size controls the tangential force and sliding distance such that their product, i.e., the tangential work, is always proportional to the debris volume, with a proportionality constant of 1 over the junction shear strength. This study provides an estimation of the debris volume without any empirical factor, resulting in a wear coefficient of unity at the debris level. Discrepant microscopic and macroscopic wear observations and models are then contextualized on the basis of this understanding. This finding offers a way to characterize the wear volume in atomistic simulations and atomic force microscope wear experiments. It also provides a fundamental basis for predicting the wear coefficient for sliding rough contacts, given the statistics of junction clusters sizes.

On the debris-level origins of adhesive wear.

PubMed

Aghababaei, Ramin; Warner, Derek H; Molinari, Jean-François

2017-07-25

Every contacting surface inevitably experiences wear. Predicting the exact amount of material loss due to wear relies on empirical data and cannot be obtained from any physical model. Here, we analyze and quantify wear at the most fundamental level, i.e., wear debris particles. Our simulations show that the asperity junction size dictates the debris volume, revealing the origins of the long-standing hypothesized correlation between the wear volume and the real contact area. No correlation, however, is found between the debris volume and the normal applied force at the debris level. Alternatively, we show that the junction size controls the tangential force and sliding distance such that their product, i.e., the tangential work, is always proportional to the debris volume, with a proportionality constant of 1 over the junction shear strength. This study provides an estimation of the debris volume without any empirical factor, resulting in a wear coefficient of unity at the debris level. Discrepant microscopic and macroscopic wear observations and models are then contextualized on the basis of this understanding. This finding offers a way to characterize the wear volume in atomistic simulations and atomic force microscope wear experiments. It also provides a fundamental basis for predicting the wear coefficient for sliding rough contacts, given the statistics of junction clusters sizes.

On the debris-level origins of adhesive wear

PubMed Central

Warner, Derek H.; Molinari, Jean-François

2017-01-01

Every contacting surface inevitably experiences wear. Predicting the exact amount of material loss due to wear relies on empirical data and cannot be obtained from any physical model. Here, we analyze and quantify wear at the most fundamental level, i.e., wear debris particles. Our simulations show that the asperity junction size dictates the debris volume, revealing the origins of the long-standing hypothesized correlation between the wear volume and the real contact area. No correlation, however, is found between the debris volume and the normal applied force at the debris level. Alternatively, we show that the junction size controls the tangential force and sliding distance such that their product, i.e., the tangential work, is always proportional to the debris volume, with a proportionality constant of 1 over the junction shear strength. This study provides an estimation of the debris volume without any empirical factor, resulting in a wear coefficient of unity at the debris level. Discrepant microscopic and macroscopic wear observations and models are then contextualized on the basis of this understanding. This finding offers a way to characterize the wear volume in atomistic simulations and atomic force microscope wear experiments. It also provides a fundamental basis for predicting the wear coefficient for sliding rough contacts, given the statistics of junction clusters sizes. PMID:28696291

Mechanism of opening a sliding clamp

PubMed Central

Douma, Lauren G.; Yu, Kevin K.; England, Jennifer K.

2017-01-01

Abstract Clamp loaders load ring-shaped sliding clamps onto DNA where the clamps serve as processivity factors for DNA polymerases. In the first stage of clamp loading, clamp loaders bind and stabilize clamps in an open conformation, and in the second stage, clamp loaders place the open clamps around DNA so that the clamps encircle DNA. Here, the mechanism of the initial clamp opening stage is investigated. Mutations were introduced into the Escherichia coli β-sliding clamp that destabilize the dimer interface to determine whether the formation of an open clamp loader–clamp complex is dependent on spontaneous clamp opening events. In other work, we showed that mutation of a positively charged Arg residue at the β-dimer interface and high NaCl concentrations destabilize the clamp, but neither facilitates the formation of an open clamp loader–clamp complex in experiments presented here. Clamp opening reactions could be fit to a minimal three-step ‘bind-open-lock’ model in which the clamp loader binds a closed clamp, the clamp opens, and subsequent conformational rearrangements ‘lock’ the clamp loader–clamp complex in a stable open conformation. Our results support a model in which the E. coli clamp loader actively opens the β-sliding clamp. PMID:28973453

AutoGNI, the Robot Under the Aircraft Floor: An Automated System for Sampling Giant Aerosol Particles by Impaction in the Free Airstream Outside a Research Aircraft

NASA Astrophysics Data System (ADS)

Jensen, J. B.; Schwenz, K.; Aquino, J.; Carnes, J.; Webster, C.; Munnerlyn, J.; Wissman, T.; Lugger, T.

2017-12-01

Giant sea-salt aerosol particles, also called Giant Cloud Condensation Nuclei (GCCN), have been proposed as a means of rapidly forming precipitation sized drizzle drops in warm marine clouds (e.g., Jensen and Nugent, 2017). Such rare particles are best sampled from aircraft in air below cloud base, where normal laser optical instruments have too low sample volume to give statistically significant samples of the large particle tail. An automated sampling system (the AutoGNI) has been built to operate from inside a pressurized aircraft. Under the aircraft floor, a pressurized vessel contains 32 custom-built polycarbonate microscope slides. Using robotics with 5 motor drives and 18 positioning switches, the AutoGNI can take slides from their holding cassettes, pass them onto a caddy in an airfoil that extends 200 mm outside the aircraft, where they are exposed in the free airstream, thus avoiding the usual problems with large particle losses in air intakes. Slides are typically exposed for 10-30 s in the marine boundary layer, giving sample volumes of about 100-300 L or more. Subsequently the slides are retracted into the pressure vessel, stored and transported for laboratory microscope image analysis, in order to derive size-distribution histograms. While the aircraft is flying, the AutoGNI system is remotely controlled from a laptop on the ground, using an encrypted commercial satellite connection to the NSF/NCAR GV research aircraft's main server, and onto the AutoGNI microprocessor. The sampling of such GCCN is becoming increasingly important in order to provide complete input data for model calculations of aerosol-cloud interactions and their feedbacks in climate prediction. The AutoGNI has so far been sampling sea-salt GCCN in the Magellan Straight during the 2016 ORCAS project and over the NW Pacific during the 2017 ARISTO project, both from the NSF/NCAR GV research aircraft. Sea-salt particle sizes of 1.4 - 32 μm dry diameter have been observed.

Synthesis and characterization of poly lactic acid and multiwall carbon nano-tubes mixtures

NASA Astrophysics Data System (ADS)

Kumar LG, Santhosh; del A. Cardona, Rocío; Berríos-Soto, Melvin; Santiago-Avilés, Jorge J.

2011-10-01

The motivation for this study is to reproduce processing conditions which lead to the formation of photo or photoinduced thermal actuation, combined with inexpensive, environmentally friendly (easily degradable) materials. Commercially available polymer, poly lactic acid (PLA), was used in our studies. PLA is a well know biodegradable polymer naturally obtained from corn. PLA was received as a solid resin in pellet form and dissolved in 1:3 acetone/chloroform solutions, to achieve the proper electrospinning kinematic viscosity. Once in the liquid phase, the material was mixed with commercially available multi-walled carbon nanotubes (MWCNTs) at varying concentrations and dispersed by severe sonication. The mixtures was electrospun at room temperature using a home built electrospinning apparatus capable of depositing randomly oriented fiber mats or oriented fibers onto different substrates, ranging from oxidized silicon wafers, alumina squares or glass microscope slides. The fibers diameters and lengths are statistically distributed following a log-normal distribution and the mean and dispersion are controlled by spinning parameters. Once the fibers were electrospun, they were compositionally, morphologically and structurally characterized by thermal and gravimetric analysis (TGA/DTA), rheology, imaging using a focused Ion Beam Scanning Electron Microscope (IBSEM), and IR /Raman methodologies. These studies can be used to explore PLA-MWCNTs mixtures suitability in applications such as super-capacitor technology, which would enable us to pursue further research in this field, while focusing on improving the electro spinning conditions so as to be able to better anticipate fiber morphology to generate a consistent regime of fibers.

Tissue Photolithography

NASA Technical Reports Server (NTRS)

Wade, Lawrence A.; Kartalov, Emil; Shibata, Darryl; Taylor, Clive

2011-01-01

Tissue lithography will enable physicians and researchers to obtain macromolecules with high purity (greater than 90 percent) from desired cells in conventionally processed, clinical tissues by simply annotating the desired cells on a computer screen. After identifying the desired cells, a suitable lithography mask will be generated to protect the contents of the desired cells while allowing destruction of all undesired cells by irradiation with ultraviolet light. The DNA from the protected cells can be used in a number of downstream applications including DNA sequencing. The purity (i.e., macromolecules isolated form specific cell types) of such specimens will greatly enhance the value and information of downstream applications. In this method, the specific cells are isolated on a microscope slide using photolithography, which will be faster, more specific, and less expensive than current methods. It relies on the fact that many biological molecules such as DNA are photosensitive and can be destroyed by ultraviolet irradiation. Therefore, it is possible to protect the contents of desired cells, yet destroy undesired cells. This approach leverages the technologies of the microelectronics industry, which can make features smaller than 1 micrometer with photolithography. A variety of ways has been created to achieve identification of the desired cell, and also to designate the other cells for destruction. This can be accomplished through chrome masks, direct laser writing, and also active masking using dynamic arrays. Image recognition is envisioned as one method for identifying cell nuclei and cell membranes. The pathologist can identify the cells of interest using a microscopic computerized image of the slide, and appropriate custom software. In one of the approaches described in this work, the software converts the selection into a digital mask that can be fed into a direct laser writer, e.g. the Heidelberg DWL66. Such a machine uses a metalized glass plate (with chrome metallization) on which there is a thin layer of photoresist. The laser transfers the digital mask onto the photoresist by direct writing, with typical best resolution of 2 micrometers. The plate is then developed to remove the exposed photoresist, which leaves the exposed areas susceptible to chemical chrome etch. The etch removes the unprotected chrome. The rest of the photoresist is then removed, by either ultraviolet organic solvent or over-development. The remaining chrome pattern is quickly oxidized by atmospheric exposure (typically within 30 seconds). The ready chrome mask is now applied to the tissue slide and aligned manually, or using automatic software and pre-designed alignment marks. The slide plate sandwich is then exposed to UV to destroy the DNA of the unwanted cells. The slide and plate are separated and the slide is processed in a standard way to prepare for polymerase chain reaction (PCR) and potential identification of cancer sequences.

Formation Flying in Earth, Libration, and Distant Retrograde Orbits

NASA Technical Reports Server (NTRS)

Folta, David C.

2004-01-01

This slide presentation examines the current and future state of formation flying, LEO formations, control strategies for flight in the vicinity of the libration points, and distant retrograde orbit formations. This discussion of LEO formations includes background on perturbation theory/accelerations and LEO formation flying. The discussion of strategies for formation flight in the vicinity of the libration points includes libration missions and natural and controlled libration orbit formations. A reference list is included.

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

Superlubricity of Graphite Induced by Multiple Transferred Graphene Nanoflakes.

PubMed

Li, Jinjin; Gao, Tianyang; Luo, Jianbin

2018-03-01

2D or 3D layered materials, such as graphene, graphite, and molybdenum disulfide, usually exhibit superlubricity properties when sliding occurs between the incommensurate interface lattices. This study reports the superlubricity between graphite and silica under ambient conditions, induced by the formation of multiple transferred graphene nanoflakes on the asperities of silica surfaces after the initial frictional sliding. The friction coefficient can be reduced to as low as 0.0003 with excellent robustness and is independent of the surface roughness, sliding velocities, and rotation angles. The superlubricity mechanism can be attributed to the extremely weak interaction and easy sliding between the transferred graphene nanoflakes and graphite in their incommensurate contact. This finding has important implications for developing approaches to achieve superlubricity of layered materials at the nanoscale by tribointeractions.

Superlubricity of Graphite Induced by Multiple Transferred Graphene Nanoflakes

PubMed Central

Gao, Tianyang; Luo, Jianbin

2018-01-01

Abstract 2D or 3D layered materials, such as graphene, graphite, and molybdenum disulfide, usually exhibit superlubricity properties when sliding occurs between the incommensurate interface lattices. This study reports the superlubricity between graphite and silica under ambient conditions, induced by the formation of multiple transferred graphene nanoflakes on the asperities of silica surfaces after the initial frictional sliding. The friction coefficient can be reduced to as low as 0.0003 with excellent robustness and is independent of the surface roughness, sliding velocities, and rotation angles. The superlubricity mechanism can be attributed to the extremely weak interaction and easy sliding between the transferred graphene nanoflakes and graphite in their incommensurate contact. This finding has important implications for developing approaches to achieve superlubricity of layered materials at the nanoscale by tribointeractions. PMID:29593965

Localization of Diagnostically Relevant Regions of Interest in Whole Slide Images: a Comparative Study.

PubMed

Mercan, Ezgi; Aksoy, Selim; Shapiro, Linda G; Weaver, Donald L; Brunyé, Tad T; Elmore, Joann G

2016-08-01

Whole slide digital imaging technology enables researchers to study pathologists' interpretive behavior as they view digital slides and gain new understanding of the diagnostic medical decision-making process. In this study, we propose a simple yet important analysis to extract diagnostically relevant regions of interest (ROIs) from tracking records using only pathologists' actions as they viewed biopsy specimens in the whole slide digital imaging format (zooming, panning, and fixating). We use these extracted regions in a visual bag-of-words model based on color and texture features to predict diagnostically relevant ROIs on whole slide images. Using a logistic regression classifier in a cross-validation setting on 240 digital breast biopsy slides and viewport tracking logs of three expert pathologists, we produce probability maps that show 74 % overlap with the actual regions at which pathologists looked. We compare different bag-of-words models by changing dictionary size, visual word definition (patches vs. superpixels), and training data (automatically extracted ROIs vs. manually marked ROIs). This study is a first step in understanding the scanning behaviors of pathologists and the underlying reasons for diagnostic errors.

Assessing and Improving Student Organizations: Resources for Facilitators CD-ROM. The Assessing and Improving Student Organization (AISO) Program

ERIC Educational Resources Information Center

Nolfi, Tricia; Ruben, Brent D.

2010-01-01

This companion to the "Guide for Students" and "Student Workbook" includes the complete set of PowerPoint slides, a PDF of the Facilitator's Guide in PPT (PowerPoint) slide show format, and PDFs of all scoring sheets, handouts and project planning guides needed for the AISO (Assessing and Improving Student Organization) process. The Assessing and…

Dynamic effects in friction and adhesion through cooperative rupture and formation of supramolecular bonds.

PubMed

Blass, Johanna; Albrecht, Marcel; Bozna, Bianca L; Wenz, Gerhard; Bennewitz, Roland

2015-05-07

We introduce a molecular toolkit for studying the dynamics in friction and adhesion from the single molecule level to effects of multivalency. As experimental model system we use supramolecular bonds established by the inclusion of ditopic adamantane connector molecules into two surface-bound cyclodextrin molecules, attached to a tip of an atomic force microscope (AFM) and to a flat silicon surface. The rupture force of a single bond does not depend on the pulling rate, indicating that the fast complexation kinetics of adamantane and cyclodextrin are probed in thermal equilibrium. In contrast, the pull-off force for a group of supramolecular bonds depends on the unloading rate revealing a non-equilibrium situation, an effect discussed as the combined action of multivalency and cantilever inertia effects. Friction forces exhibit a stick-slip characteristic which is explained by the cooperative rupture of groups of host-guest bonds and their rebinding. No dependence of friction on the sliding velocity has been observed in the accessible range of velocities due to fast rebinding and the negligible delay of cantilever response in AFM lateral force measurements.

Asperity-Level Origins of Transition from Mild to Severe Wear

NASA Astrophysics Data System (ADS)

Aghababaei, Ramin; Brink, Tobias; Molinari, Jean-François

2018-05-01

Wear is the inevitable damage process of surfaces during sliding contact. According to the well-known Archard's wear law, the wear volume scales with the real contact area and as a result is proportional to the load. Decades of wear experiments, however, show that this relation only holds up to a certain load limit, above which the linearity is broken and a transition from mild to severe wear occurs. We investigate the microscopic origins of this breakdown and the corresponding wear transition at the asperity level. Our atomistic simulations reveal that the interaction between subsurface stress fields of neighboring contact spots promotes the transition from mild to severe wear. The results show that this interaction triggers the deep propagation of subsurface cracks and the eventual formation of large debris particles, with a size corresponding to the apparent contact area of neighboring contact spots. This observation explains the breakdown of the linear relation between the wear volume and the normal load in the severe wear regime. This new understanding highlights the critical importance of studying contact beyond the elastic limit and single-asperity models.

Rapid Covalent Modification of Silicon Oxide Surfaces through Microwave-Assisted Reactions with Alcohols.

PubMed

Lee, Austin W H; Gates, Byron D

2016-07-26

We demonstrate the method of a rapid covalent modification of silicon oxide surfaces with alcohol-containing compounds with assistance by microwave reactions. Alcohol-containing compounds are prevalent reagents in the laboratory, which are also relatively easy to handle because of their stability against exposure to atmospheric moisture. The condensation of these alcohols with the surfaces of silicon oxides is often hindered by slow reaction kinetics. Microwave radiation effectively accelerates this condensation reaction by heating the substrates and/or solvents. A variety of substrates were modified in this demonstration, such as silicon oxide films of various thicknesses, glass substrates such as microscope slides (soda lime), and quartz. The monolayers prepared through this strategy demonstrated the successful formation of covalent surface modifications of silicon oxides with water contact angles of up to 110° and typical hysteresis values of 2° or less. An evaluation of the hydrolytic stability of these monolayers demonstrated their excellent stability under acidic conditions. The techniques introduced in this article were successfully applied to tune the surface chemistry of silicon oxides to achieve hydrophobic, oleophobic, and/or charged surfaces.

Universal biomimetic preparation and immobilization of layered double hydroxide films and adsorption behavior

NASA Astrophysics Data System (ADS)

Zhou, Wei; Zhang, Wenpeng; Chen, Zilin

2017-01-01

Preparation and immobilization of layered double hydroxides (LDHs) film onto multiple substrates is important and challenging in functional materials fields by date. In this work, a simple and universal polydopamine (PD)-based layer-by-layer assembly strategy was developed for the immobilization of LDHs film onto surfaces such as polypropylene chip, glass slides and metal coins. The surface of substrates was firstly modified by polydopamine functionalization, and then LDHs film was synthesized via urea method and directly immobilized on the PD layer by in situ growing strategy in one step. The PD layer as well as the final LDHs film was characterized by energy dispersive X-ray spectroscopy, scanning electron microscope, infrared spectroscopy, X-ray diffraction pattern and X-ray photoelectron spectra. It has been demonstrated the formation of the dense and homogeneous nanoscaled LDHs film with 400 nm thickness. Adsorption behavior of the fabricated NiAl-LDHs film toward anionic dyes and pharmaceuticals was further assessed. To demonstrate their extensive application, fast and high efficient adsorption of anionic dyes and pharmaceuticals was achieved by NiAl-LDHs-modified polypropylene centrifugal tube.

Acoustic Sample Deposition MALDI-MS (ASD-MALDI-MS): A Novel Process Flow for Quality Control Screening of Compound Libraries.

PubMed

Chin, Jefferson; Wood, Elizabeth; Peters, Grace S; Drexler, Dieter M

2016-02-01

In the early stages of drug discovery, high-throughput screening (HTS) of compound libraries against pharmaceutical targets is a common method to identify potential lead molecules. For these HTS campaigns to be efficient and successful, continuous quality control of the compound collection is necessary and crucial. However, the large number of compound samples and the limited sample amount pose unique challenges. Presented here is a proof-of-concept study for a novel process flow for the quality control screening of small-molecule compound libraries that consumes only minimal amounts of samples and affords compound-specific molecular data. This process employs an acoustic sample deposition (ASD) technique for the offline sample preparation by depositing nanoliter volumes in an array format onto microscope glass slides followed by matrix-assisted laser desorption/ionization mass spectrometric (MALDI-MS) analysis. An initial study of a 384-compound array employing the ASD-MALDI-MS workflow resulted in a 75% first-pass positive identification rate with an analysis time of <1 s per sample. © 2015 Society for Laboratory Automation and Screening.

[Development of an incubation system for an inverted microscopy for long-term observation of cell cultures using chamber slides].

PubMed

Feicht, W; Buchner, A; Riesenberg, R

2001-05-01

Trifunctional bispecific antibodies open up new immunological possibilities in tumour treatment. Prior to clinical application, comprehensive investigations using animal models and in vitro examinations need to be done. To investigate long-term interactions between various immunologically active blood cells and individual tumour cells in the presence of antibodies, we developed an incubation system for experimental cell cultures on an inverted microscope. The system consists of a perspex box with a central moisture chamber with integrated water reservoir, external air circulation heating, and a CO2 supply. The sterile cell cultures are located in the wells of a slide positioned within a depression in the water reservoir. The newly developed incubation system enables continuous observation over the long term of experiments under optimal cell cultures conditions in combination with modern video techniques.

Sliding of microtubules by a team of dynein motors: Understanding the effect of spatial distribution of motor tails and mutual exclusion of motor heads on microtubules

NASA Astrophysics Data System (ADS)

Singh, Hanumant Pratap; Takshak, Anjneya; Mall, Utkarsh; Kunwar, Ambarish

2016-06-01

Molecular motors are natural nanomachines that use the free energy released from ATP hydrolysis to generate mechanical forces. Cytoplasmic dynein motors often work collectively as a team to drive important processes such as axonal growth, proplatelet formation and mitosis, as forces generated by single motors are insufficient. A large team of dynein motors is used to slide cytoskeletal microtubules with respect to one another during the process of proplatelet formation and axonal growth. These motors attach to a cargo microtubule via their tail domains, undergo the process of detachment and reattachment of their head domains on another track microtubule, while sliding the cargo microtubule along the track. Traditional continuum/mean-field approaches used in the past are not ideal for studying the sliding mechanism of microtubules, as they ignore spatial and temporal fluctuations due to different possible distributions of motor tails on cargo filament, as well as binding/unbinding of motors from their track. Therefore, these models cannot be used to address important questions such as how the distribution of motor tails on microtubules, or how the mutual exclusion of motor heads on microtubule tracks affects the sliding velocity of cargo microtubule. To answer these, here we use a computational stochastic model where we model each dynein motor explicitly. In our model, we use both random as well as uniform distributions of dynein motors on cargo microtubule, as well as mutual exclusion of motors on microtubule tracks. We find that sliding velocities are least affected by the distribution of motor tails on microtubules, whereas they are greatly affected by mutual exclusion of motor heads on microtubule tracks. We also find that sliding velocity depends on the length of cargo microtubule if mutual exclusion among motor heads is considered.

Pathology economic model tool: a novel approach to workflow and budget cost analysis in an anatomic pathology laboratory.

PubMed

Muirhead, David; Aoun, Patricia; Powell, Michael; Juncker, Flemming; Mollerup, Jens

2010-08-01

The need for higher efficiency, maximum quality, and faster turnaround time is a continuous focus for anatomic pathology laboratories and drives changes in work scheduling, instrumentation, and management control systems. To determine the costs of generating routine, special, and immunohistochemical microscopic slides in a large, academic anatomic pathology laboratory using a top-down approach. The Pathology Economic Model Tool was used to analyze workflow processes at The Nebraska Medical Center's anatomic pathology laboratory. Data from the analysis were used to generate complete cost estimates, which included not only materials, consumables, and instrumentation but also specific labor and overhead components for each of the laboratory's subareas. The cost data generated by the Pathology Economic Model Tool were compared with the cost estimates generated using relative value units. Despite the use of automated systems for different processes, the workflow in the laboratory was found to be relatively labor intensive. The effect of labor and overhead on per-slide costs was significantly underestimated by traditional relative-value unit calculations when compared with the Pathology Economic Model Tool. Specific workflow defects with significant contributions to the cost per slide were identified. The cost of providing routine, special, and immunohistochemical slides may be significantly underestimated by traditional methods that rely on relative value units. Furthermore, a comprehensive analysis may identify specific workflow processes requiring improvement.

Phase diagram for inertial granular flows.

PubMed

DeGiuli, E; McElwaine, J N; Wyart, M

2016-07-01

Flows of hard granular materials depend strongly on the interparticle friction coefficient μ_{p} and on the inertial number I, which characterizes proximity to the jamming transition where flow stops. Guided by numerical simulations, we derive the phase diagram of dense inertial flow of spherical particles, finding three regimes for 10^{-4}≲I≲10^{-1}: frictionless, frictional sliding, and rolling. These are distinguished by the dominant means of energy dissipation, changing from collisional to sliding friction, and back to collisional, as μ_{p} increases from zero at constant I. The three regimes differ in their kinetics and rheology; in particular, the velocity fluctuations and the stress ratio both display nonmonotonic behavior with μ_{p}, corresponding to transitions between the three regimes of flow. We rationalize the phase boundaries between these regimes, show that energy balance yields scaling relations between microscopic properties in each of them, and derive the strain scale at which particles lose memory of their velocity. For the frictional sliding regime most relevant experimentally, we find for I≥10^{-2.5} that the growth of the macroscopic friction μ(I) with I is induced by an increase of collisional dissipation. This implies in that range that μ(I)-μ(0)∼I^{1-2b}, where b≈0.2 is an exponent that characterizes both the dimensionless velocity fluctuations L∼I^{-b} and the density of sliding contacts χ∼I^{b}.

New Trends of Emerging Technologies in Digital Pathology.

PubMed

Bueno, Gloria; Fernández-Carrobles, M Milagro; Deniz, Oscar; García-Rojo, Marcial

2016-01-01

The future paradigm of pathology will be digital. Instead of conventional microscopy, a pathologist will perform a diagnosis through interacting with images on computer screens and performing quantitative analysis. The fourth generation of virtual slide telepathology systems, so-called virtual microscopy and whole-slide imaging (WSI), has allowed for the storage and fast dissemination of image data in pathology and other biomedical areas. These novel digital imaging modalities encompass high-resolution scanning of tissue slides and derived technologies, including automatic digitization and computational processing of whole microscopic slides. Moreover, automated image analysis with WSI can extract specific diagnostic features of diseases and quantify individual components of these features to support diagnoses and provide informative clinical measures of disease. Therefore, the challenge is to apply information technology and image analysis methods to exploit the new and emerging digital pathology technologies effectively in order to process and model all the data and information contained in WSI. The final objective is to support the complex workflow from specimen receipt to anatomic pathology report transmission, that is, to improve diagnosis both in terms of pathologists' efficiency and with new information. This article reviews the main concerns about and novel methods of digital pathology discussed at the latest workshop in the field carried out within the European project AIDPATH (Academia and Industry Collaboration for Digital Pathology). © 2016 S. Karger AG, Basel.

Morphology and frictional properties of scales of Pseudopus apodus (Anguidae, Reptilia).

PubMed

Spinner, Marlene; Bleckmann, Horst; Westhoff, Guido

2015-06-01

In the lizard family Anguidae different levels of limb reduction exist up to a completely limbless body. The locomotion patterns of limbless anguid lizards are similar to the undulating and concertina movements of snakes. Additionally, anguid lizards frequently use a third mode of locomotion, called slide-pushing. During slide-pushing the undulating moving body slides on the ground, while the posterior part of the body is pressed against the substrate. Whereas the macroscopic and microscopic adaptations of snake scales to limbless locomotion are well described, the micromorphology of anguid lizard scales has never been examined. Therefore we studied the macro- and micromorphology of the scales of Pseudopus apodus, an anguid lizard with a snakelike body. In addition, we measured the frictional properties of Pseudopus scales. Our data show that the microstructures of the ventral scales of this anguid lizard are less developed than in snakes. We found, however, a rostro-caudal gradient in macroscopic structuring. Whereas the ventral side of the anterior body was nearly unstructured, the tail had macroscopic longitudinal ridges. Our frictional measurements on rough substrates revealed that the ridges provide a frictional anisotropy: friction was higher in the lateral than in the rostral direction. The observed frictional properties are advantageous for a tail-based slide-pushing locomotion, for which a tail with a high lateral friction is most effective in generating propulsion. Copyright © 2015 Elsevier GmbH. All rights reserved.

Modelling the initiation of basal sliding

NASA Astrophysics Data System (ADS)

Mantelli, E.; Schoof, C.

2017-12-01

The initiation of basal sliding is a thermally-controlled process that affects ice speed, englacial heat transport, and melt water production at the bed, and ultimately influences the large-scale dynamics of ice sheets. From a modelling perspective, describing the onset of sliding in thin-film models suitable for ice sheet scale simulations is problematic. In particular, previous work concluded that, under shallow-ice mechanics, the scenario of a hard switch from frozen to molten bed leads to an infinite vertical velocity at the onset, and higher-order mechanical formulations are needed to describe sliding initiation. An alternative view considers the occurrence of subtemperate sliding, which allows for a smooth sliding velocity across the onset. However, the sliding velocity decreases rapidly as temperature drops below the melting point, thus raising the issue of whether a mechanical model that does not resolve the ice sheet thickness scale is ever appropriate to model the onset of sliding. In this study we first present a boundary layer model for the hard switch scenario. Our analysis, which considers a thermo-mechanically coupled Stokes flow near the onset, shows that the abrupt onset of sliding is never possible. In fact, the acceleration of ice flow deflects the flowlines towards the bed, which freezes again immediately downstream to the onset. This leads to the conclusion that the sliding velocity must change smoothly across the onset, thus the temperature dependence of sliding needs to be taken into account. In this context, we examine a limiting case of standard temperature-dependent sliding laws, where sliding onset takes the form of an extended transition region interposed between fully frozen and temperate bed. In the transition region basal temperature is at the melting point, and the sliding velocity varies smoothly as dictated by the energy budget of the bed. As the extent of this region is not small compared to the ice sheet length scale, we couple this description of sliding initiation to a shallow-ice model, which is appropriate so long as sliding velocities are not large. We present numerical and analytical results concerning the steady states and the stability of this ice sheet model, and discuss implications of sliding initiation with respect to pattern formation.

Dermal Influence on Epidermal Resurfacing during the Repair of Split Thickness Wounds.

DTIC Science & Technology

1983-08-15

by exposing purified platelets to thrombin also stimulated the proliferation of mooth muscle cells. They concluded that much of the growth-proanting...easily separated with forceps. The moist epidermis was placed on a microscope slide with the stratm corneum (and protruding hair shafts) against the glass...hcmogenate intradermally around the wound bed or using a viscous vehicle for the platelet factor, such as an ointment -based emollient. 3) The active factor

Human Expertise Helps Computer Classify Images

NASA Technical Reports Server (NTRS)

Rorvig, Mark E.

1991-01-01

Two-domain method of computational classification of images requires less computation than other methods for computational recognition, matching, or classification of images or patterns. Does not require explicit computational matching of features, and incorporates human expertise without requiring translation of mental processes of classification into language comprehensible to computer. Conceived to "train" computer to analyze photomicrographs of microscope-slide specimens of leucocytes from human peripheral blood to distinguish between specimens from healthy and specimens from traumatized patients.

Application of principal component analysis to multispectral-multimodal optical image analysis for malaria diagnostics.

PubMed

Omucheni, Dickson L; Kaduki, Kenneth A; Bulimo, Wallace D; Angeyo, Hudson K

2014-12-11

Multispectral imaging microscopy is a novel microscopic technique that integrates spectroscopy with optical imaging to record both spectral and spatial information of a specimen. This enables acquisition of a large and more informative dataset than is achievable in conventional optical microscopy. However, such data are characterized by high signal correlation and are difficult to interpret using univariate data analysis techniques. In this work, the development and application of a novel method which uses principal component analysis (PCA) in the processing of spectral images obtained from a simple multispectral-multimodal imaging microscope to detect Plasmodium parasites in unstained thin blood smear for malaria diagnostics is reported. The optical microscope used in this work has been modified by replacing the broadband light source (tungsten halogen lamp) with a set of light emitting diodes (LEDs) emitting thirteen different wavelengths of monochromatic light in the UV-vis-NIR range. The LEDs are activated sequentially to illuminate same spot of the unstained thin blood smears on glass slides, and grey level images are recorded at each wavelength. PCA was used to perform data dimensionality reduction and to enhance score images for visualization as well as for feature extraction through clusters in score space. Using this approach, haemozoin was uniquely distinguished from haemoglobin in unstained thin blood smears on glass slides and the 590-700 spectral range identified as an important band for optical imaging of haemozoin as a biomarker for malaria diagnosis. This work is of great significance in reducing the time spent on staining malaria specimens and thus drastically reducing diagnosis time duration. The approach has the potential of replacing a trained human eye with a trained computerized vision system for malaria parasite blood screening.

Evaluation of a standardized procedure for [corrected] microscopic cell counts [corrected] in body fluids.

PubMed

Emerson, Jane F; Emerson, Scott S

2005-01-01

A standardized urinalysis and manual microscopic cell counting system was evaluated for its potential to reduce intra- and interoperator variability in urine and cerebrospinal fluid (CSF) cell counts. Replicate aliquots of pooled specimens were submitted blindly to technologists who were instructed to use either the Kova system with the disposable Glasstic slide (Hycor Biomedical, Inc., Garden Grove, CA) or the standard operating procedure of the University of California-Irvine (UCI), which uses plain glass slides for urine sediments and hemacytometers for CSF. The Hycor system provides a mechanical means of obtaining a fixed volume of fluid in which to resuspend the sediment, and fixes the volume of specimen to be microscopically examined by using capillary filling of a chamber containing in-plane counting grids. Ninety aliquots of pooled specimens of each type of body fluid were used to assess the inter- and intraoperator reproducibility of the measurements. The variability of replicate Hycor measurements made on a single specimen by the same or different observers was compared with that predicted by a Poisson distribution. The Hycor methods generally resulted in test statistics that were slightly lower than those obtained with the laboratory standard methods, indicating a trend toward decreasing the effects of various sources of variability. For 15 paired aliquots of each body fluid, tests for systematically higher or lower measurements with the Hycor methods were performed using the Wilcoxon signed-rank test. Also examined was the average difference between the Hycor and current laboratory standard measurements, along with a 95% confidence interval (CI) for the true average difference. Without increasing labor or the requirement for attention to detail, the Hycor method provides slightly better interrater comparisons than the current method used at UCI. Copyright 2005 Wiley-Liss, Inc.

History-dependent friction and slow slip from time-dependent microscopic junction laws studied in a statistical framework

NASA Astrophysics Data System (ADS)

Thøgersen, Kjetil; Trømborg, Jørgen Kjoshagen; Sveinsson, Henrik Andersen; Malthe-Sørenssen, Anders; Scheibert, Julien

2014-05-01

To study how macroscopic friction phenomena originate from microscopic junction laws, we introduce a general statistical framework describing the collective behavior of a large number of individual microjunctions forming a macroscopic frictional interface. Each microjunction can switch in time between two states: a pinned state characterized by a displacement-dependent force and a slipping state characterized by a time-dependent force. Instead of tracking each microjunction individually, the state of the interface is described by two coupled distributions for (i) the stretching of pinned junctions and (ii) the time spent in the slipping state. This framework allows for a whole family of microjunction behavior laws, and we show how it represents an overarching structure for many existing models found in the friction literature. We then use this framework to pinpoint the effects of the time scale that controls the duration of the slipping state. First, we show that the model reproduces a series of friction phenomena already observed experimentally. The macroscopic steady-state friction force is velocity dependent, either monotonic (strengthening or weakening) or nonmonotonic (weakening-strengthening), depending on the microscopic behavior of individual junctions. In addition, slow slip, which has been reported in a wide variety of systems, spontaneously occurs in the model if the friction contribution from junctions in the slipping state is time weakening. Next, we show that the model predicts a nontrivial history dependence of the macroscopic static friction force. In particular, the static friction coefficient at the onset of sliding is shown to increase with increasing deceleration during the final phases of the preceding sliding event. We suggest that this form of history dependence of static friction should be investigated in experiments, and we provide the acceleration range in which this effect is expected to be experimentally observable.

Mobile microscopy as a screening tool for oral cancer in India: A pilot study

PubMed Central

Skandarajah, Arunan; Sunny, Sumsum P.; Gurpur, Praveen; Reber, Clay D.; D’Ambrosio, Michael V.; Raghavan, Nisheena; James, Bonney Lee; Ramanjinappa, Ravindra D.; Suresh, Amritha; Kandasarma, Uma; Birur, Praveen; Kumar, Vinay V.; Galmeanu, Honorius-Cezar; Itu, Alexandru Mihail; Modiga-Arsu, Mihai; Rausch, Saskia; Sramek, Maria; Kollegal, Manohar; Paladini, Gianluca; Kuriakose, Moni; Koch, Felix; Fletcher, Daniel

2017-01-01

Oral cancer is the most common type of cancer among men in India and other countries in South Asia. Late diagnosis contributes significantly to this mortality, highlighting the need for effective and specific point-of-care diagnostic tools. The same regions with high prevalence of oral cancer have seen extensive growth in mobile phone infrastructure, which enables widespread access to telemedicine services. In this work, we describe the evaluation of an automated tablet-based mobile microscope as an adjunct for telemedicine-based oral cancer screening in India. Brush biopsy, a minimally invasive sampling technique was combined with a simplified staining protocol and a tablet-based mobile microscope to facilitate local collection of digital images and remote evaluation of the images by clinicians. The tablet-based mobile microscope (CellScope device) combines an iPad Mini with collection optics, LED illumination and Bluetooth-controlled motors to scan a slide specimen and capture high-resolution images of stained brush biopsy samples. Researchers at the Mazumdar Shaw Medical Foundation (MSMF) in Bangalore, India used the instrument to collect and send randomly selected images of each slide for telepathology review. Evaluation of the concordance between gold standard histology, conventional microscopy cytology, and remote pathologist review of the images was performed as part of a pilot study of mobile microscopy as a screening tool for oral cancer. Results indicated that the instrument successfully collected images of sufficient quality to enable remote diagnoses that show concordance with existing techniques. Further studies will evaluate the effectiveness of oral cancer screening with mobile microscopy by minimally trained technicians in low-resource settings. PMID:29176904

History-dependent friction and slow slip from time-dependent microscopic junction laws studied in a statistical framework.

PubMed

Thøgersen, Kjetil; Trømborg, Jørgen Kjoshagen; Sveinsson, Henrik Andersen; Malthe-Sørenssen, Anders; Scheibert, Julien

2014-05-01

To study how macroscopic friction phenomena originate from microscopic junction laws, we introduce a general statistical framework describing the collective behavior of a large number of individual microjunctions forming a macroscopic frictional interface. Each microjunction can switch in time between two states: a pinned state characterized by a displacement-dependent force and a slipping state characterized by a time-dependent force. Instead of tracking each microjunction individually, the state of the interface is described by two coupled distributions for (i) the stretching of pinned junctions and (ii) the time spent in the slipping state. This framework allows for a whole family of microjunction behavior laws, and we show how it represents an overarching structure for many existing models found in the friction literature. We then use this framework to pinpoint the effects of the time scale that controls the duration of the slipping state. First, we show that the model reproduces a series of friction phenomena already observed experimentally. The macroscopic steady-state friction force is velocity dependent, either monotonic (strengthening or weakening) or nonmonotonic (weakening-strengthening), depending on the microscopic behavior of individual junctions. In addition, slow slip, which has been reported in a wide variety of systems, spontaneously occurs in the model if the friction contribution from junctions in the slipping state is time weakening. Next, we show that the model predicts a nontrivial history dependence of the macroscopic static friction force. In particular, the static friction coefficient at the onset of sliding is shown to increase with increasing deceleration during the final phases of the preceding sliding event. We suggest that this form of history dependence of static friction should be investigated in experiments, and we provide the acceleration range in which this effect is expected to be experimentally observable.

Immunostaining of dissected zebrafish embryonic heart.

PubMed

Yang, Jingchun; Xu, Xiaolei

2012-01-10

Zebrafish embryo becomes a popular in vivo vertebrate model for studying cardiac development and human heart diseases due to its advantageous embryology and genetics. About 100-200 embryos are readily available every week from a single pair of adult fish. The transparent embryos that develop ex utero make them ideal for assessing cardiac defects. The expression of any gene can be manipulated via morpholino technology or RNA injection. Moreover, forward genetic screens have already generated a list of mutants that affect different perspectives of cardiogenesis. Whole mount immunostaining is an important technique in this animal model to reveal the expression pattern of the targeted protein to a particular tissue. However, high resolution images that can reveal cellular or subcellular structures have been difficult, mainly due to the physical location of the heart and the poor penetration of the antibodies. Here, we present a method to address these bottlenecks by dissecting heart first and then conducting the staining process on the surface of a microscope slide. To prevent the loss of small heart samples and to facilitate solution handling, we restricted the heart samples within a circle on the surface of the microscope slides drawn by an immEdge pen. After the staining, the fluorescence signals can be directly observed by a compound microscope. Our new method significantly improves the penetration for antibodies, since a heart from an embryonic fish only consists of few cell layers. High quality images from intact hearts can be obtained within a much reduced procession time for zebrafish embryos aged from day 2 to day 6. Our method can be potentially extended to stain other organs dissected from either zebrafish or other small animals. Copyright © 2012 Journal of Visualized Experiments

Surface folding in metals: a mechanism for delamination wear in sliding

PubMed Central

Mahato, Anirban; Guo, Yang; Sundaram, Narayan K.; Chandrasekar, Srinivasan

2014-01-01

Using high-resolution, in situ imaging of a hard, wedge-shaped model asperity sliding against a metal surface, we demonstrate a new mechanism for particle formation and delamination wear. Damage to the residual surface is caused by the occurrence of folds on the free surface of the prow-shaped region ahead of the wedge. This damage manifests itself as shallow crack-like features and surface tears, which are inclined at very acute angles to the surface. The transformation of folds into cracks, tears and particles is directly captured. Notably, a single sliding pass is sufficient to damage the surface, and subsequent passes result in the generation of platelet-like wear particles. Tracking the folding process at every stage from surface bumps to folds to cracks/tears/particles ensures that there is no ambiguity in capturing the mechanism of wear. Because fold formation and consequent delamination are quite general, our findings have broad applicability beyond wear itself, including implications for design of surface generation and conditioning processes. PMID:25197251

Architecture and development of a multi-stage Baiyun submarine slide complex in the Pearl River Canyon, northern South China Sea

NASA Astrophysics Data System (ADS)

Wang, Lei; Wu, Shi-Guo; Li, Qing-Ping; Wang, Da-Wei; Fu, Shao-Ying

2014-08-01

The Baiyun submarine slide complex (BSSC) along the Pearl River Canyon of the northern South China Sea has been imaged by multibeam bathymetry and 2D/3D seismic data. By means of maximum likelihood classification with slope aspect and gradient as inputs, the BSSC is subdivided into four domains, denoted as slide area I, II, III and IV. Slide area I is surrounded by cliffs on three sides and has been intensely reshaped by turbidity currents generated by other kinds of mass movement outside the area; slide area II incorporates a shield volcano with a diameter of approximately 10 km and unconfined slides possibly resulting from the toe collapse of inter-canyon ridges; slide area III is dominated by repeated slides that mainly originated from cliffs constituting the eastern boundary of the BSSC; slide area IV is distinguished by a conical seamount with a diameter of 6.5 km and a height of 375 m, and two slides probably having a common source that are separated from each other by a suite of residual strata. The BSSC is interpreted to be composed of numerous slide events, which occurred in the period from 10.5 to 5.5 Ma BP. Six specific factors may have contributed to the development of the BSSC, i.e., gas hydrate dissociation, gas-bearing sediments, submarine volcanic activity, seismicity, sedimentation rate and seafloor geomorphology. A 2D conceptual geological model combining these factors is proposed as a plausible mechanism explaining the formation of the BSSC. However, the BSSC may also have been affected by the Dongsha event (10 Ma BP) as an overriding factor.

Applications of virtual reality technology in pathology.

PubMed

Grimes, G J; McClellan, S A; Goldman, J; Vaughn, G L; Conner, D A; Kujawski, E; McDonald, J; Winokur, T; Fleming, W

1997-01-01

TelePath(SM) a telerobotic system utilizing virtual microscope concepts based on high quality still digital imaging and aimed at real-time support for surgery by remote diagnosis of frozen sections. Many hospitals and clinics have an application for the remote practice of pathology, particularly in the area of reading frozen sections in support of surgery, commonly called anatomic pathology. The goal is to project the expertise of the pathologist into the remote setting by giving the pathologist access to the microscope slides with an image quality and human interface comparable to what the pathologist would experience at a real rather than a virtual microscope. A working prototype of a virtual microscope has been defined and constructed which has the needed performance in both the image quality and human interface areas for a pathologist to work remotely. This is accomplished through the use of telerobotics and an image quality which provides the virtual microscope the same diagnostic capabilities as a real microscope. The examination of frozen sections is performed a two-dimensional world. The remote pathologist is in a virtual world with the same capabilities as a "real" microscope, but response times may be slower depending on the specific computing and telecommunication environments. The TelePath system has capabilities far beyond a normal biological microscope, such as the ability to create a low power image of the entire sample using multiple images digitally matched together; the ability to digitally retrace a viewing trajectory; and the ability to archive images using CD ROM and other mass storage devices.

[Jan Evangelista Purkynĕ and his instruments for microscopic research.

PubMed

Chvtal, A

2016-10-01

The results obtained during the studies of the microscopic structure of animal and human tissues by the famous 19th century Czech scientist Jan Evangelista Purkynĕ are already sufficiently described in a variety of older and newer publications. The contents of the present paper are an overview of the microscopes and other tools and instruments that Purkynĕ and his assistants and pupils used for research of tissue histology and during teaching, and in whose development there were directly involved. A brief overview of the development of the cutting engines suggests that the first microtome, from which all modern sliding microtomes are derived, originated under the supervision of Purkynĕ at the Institute of Physiology in Wroclaw. Purkynĕ and his assistants thus not only obtained priority results in the field of the structure of animal and human tissues, but also substantially contributed to the development of instruments and equipment for their study, which is often forgotten today.

High-resolution digital brain atlases: a Hubble telescope for the brain.

PubMed

Jones, Edward G; Stone, James M; Karten, Harvey J

2011-05-01

We describe implementation of a method for digitizing at microscopic resolution brain tissue sections containing normal and experimental data and for making the content readily accessible online. Web-accessible brain atlases and virtual microscopes for online examination can be developed using existing computer and internet technologies. Resulting databases, made up of hierarchically organized, multiresolution images, enable rapid, seamless navigation through the vast image datasets generated by high-resolution scanning. Tools for visualization and annotation of virtual microscope slides enable remote and universal data sharing. Interactive visualization of a complete series of brain sections digitized at subneuronal levels of resolution offers fine grain and large-scale localization and quantification of many aspects of neural organization and structure. The method is straightforward and replicable; it can increase accessibility and facilitate sharing of neuroanatomical data. It provides an opportunity for capturing and preserving irreplaceable, archival neurohistological collections and making them available to all scientists in perpetuity, if resources could be obtained from hitherto uninterested agencies of scientific support. © 2011 New York Academy of Sciences.

Multicolor fluorescence microscopic imaging of cancer cells on the plasmonic chip (Presentation Recording)

NASA Astrophysics Data System (ADS)

Tawa, Keiko; Sasakawa, Chisato; Yamamura, Shohei; Shibata, Izumi; Kataoka, Masatoshi

2015-09-01

A plasmonic chip which is a metal coated substrate with grating structure can provide the enhanced fluorescence by the grating-coupled surface plasmon field. In our previous studies, bright epi-fluorescence microscopic imaging of neuron cells and sensitive immunosesnsing have been reported. In this study, two kinds of breast cancer cells, MCF-7 and MDA-MB231, were observed with epi-fluorescence microscope on the plasmonic chip with 2D hole-arrays . They were multicolor stained with 4', 6-diamidino-2-phenylindole (DAPI) and allophycocyanin (APC)-labeled anti-epithelial cell adhesion molecule (EpCAM) antibody. Our plasmonic chip provided the brighter fluorescence images of these cells compared with the glass slide. Even in the cells including few EpCAM, the distribution of EpCAM was clearly observed in the cell membrane. It was found that the plasmonic chip can be one of the powerful tools to detect the marker protein existing around the chip surface even at low concentration.

[Species identification of the fragment of wood found in the left eye socket bone during exhumation of general Władysław Sikorski's corpse].

PubMed

Wasik, Radosław

2009-01-01

During the exhumation of general Władysław Sikorski's corpse, a fragment of wood was found embedded in the left eye socket bone. The wood fragment was referred by the Institute of Forensic Research to the laboratory of Department of Forest and Wood Utilization, University of Agriculture in Krakow, where investigations were performed, aiming at determining the species of the wood. The fragment was cut into 20 microm thick microtome scraps of three anatomy sections: transverse, tangential and radial. The scraps were immersed in 99.8% ethyl alcohol for 24 hours and then for about 1 hour in xylene. Subsequently, they were placed between a microscope slide and a cover-glass in Canada balsam. The thus prepared scraps were then analyzed with the use of a Jenaval Carl Zeiss microscope. On the basis of microscope observations it was determined that the investigated fragment of wood belonged to Douglas-fir species (Pseudotsuga menziesii (Mirb.) Franco).

Influence of scan strategy and molten pool configuration on microstructures and tensile properties of selective laser melting additive manufactured aluminum based parts

NASA Astrophysics Data System (ADS)

Dai, Donghua; Gu, Dongdong; Zhang, Han; Xiong, Jiapeng; Ma, Chenglong; Hong, Chen; Poprawe, Reinhart

2018-02-01

Selective laser melting additive manufacturing of the AlSi12 material parts through the re-melting of the previously solidified layer using the continuous two layers 90° rotate scan strategy was conducted. The influence of the re-melting behavior and scan strategy on the formation of the ;track-track; and ;layer-layer; molten pool boundaries (MPBs), dimensional accuracy, microstructure feature, tensile properties, microscopic sliding behavior and the fracture mechanism as loaded a tensile force has been studied. It showed that the defects, such as the part distortion, delamination and cracks, were significantly eliminated with the deformation rate less than 1%. The microstructure of a homogeneous distribution of the Si phase, no apparent grain orientation on both sides of the MPBs, was produced in the as-fabricated part, promoting the efficient transition of the load stress. Cracks preferentially initiate at the ;track-track; MPBs when the tensile stress increases to a certain value, resulting in the formation of the cleavage steps along the tensile loading direction. The cracks propagate along the ;layer-layer; MPBs, generating the fine dimples. The mechanical behavior of the SLM-processed AlSi12 parts can be significantly enhanced with the ultimate tensile strength, yield strength and elongation of 476.3 MPa, 315.5 MPa and 6.7%, respectively.

Impact of solid second phases on deformation mechanisms of naturally deformed salt rocks (Kuh-e-Namak, Dashti, Iran) and rheological stratification of the Hormuz Salt Formation

NASA Astrophysics Data System (ADS)

Závada, P.; Desbois, G.; Urai, J. L.; Schulmann, K.; Rahmati, M.; Lexa, O.; Wollenberg, U.

2015-05-01

Viscosity contrasts displayed in flow structures of a mountain namakier (Kuh-e-Namak - Dashti), between 'weak' second phase bearing rock salt and 'strong' pure rock salt types are studied for deformation mechanisms using detailed quantitative microstructural study. While the solid inclusions rich ("dirty") rock salts contain disaggregated siltstone and dolomite interlayers, "clean" salts reveal microscopic hematite and remnants of abundant fluid inclusions in non-recrystallized cores of porphyroclasts. Although the flow in both, the recrystallized "dirty" and "clean" salt types is accommodated by combined mechanisms of pressure-solution creep (PS), grain boundary sliding (GBS), transgranular microcracking and dislocation creep accommodated grain boundary migration (GBM), their viscosity contrasts observed in the field outcrops are explained by: 1) enhanced ductility of "dirty" salts due to increased diffusion rates along the solid inclusion-halite contacts than along halite-halite contacts, and 2) slow rates of intergranular diffusion due to dissolved iron and inhibited dislocation creep due to hematite inclusions for "clean" salt types Rheological contrasts inferred by microstructural analysis between both salt rock classes apply in general for the "dirty" salt forming Lower Hormuz and the "clean" salt forming the Upper Hormuz of the Hormuz Formation and imply strain rate gradients or decoupling along horizons of mobilized salt types of different composition and microstructure.

DBP formation and disinfection under current and future climates - slides

EPA Science Inventory

How to predict and monitoring DBP formation under current and future climate is a challenge and important to water plant operations and water supply security. This presentation summarizes a system approach being developed at the EPA Water Resources Adaptation Program (WRAP).

Activity-based differentiation of pathologists' workload in surgical pathology.

PubMed

Meijer, G A; Oudejans, J J; Koevoets, J J M; Meijer, C J L M

2009-06-01

Adequate budget control in pathology practice requires accurate allocation of resources. Any changes in types and numbers of specimens handled or protocols used will directly affect the pathologists' workload and consequently the allocation of resources. The aim of the present study was to develop a model for measuring the pathologists' workload that can take into account the changes mentioned above. The diagnostic process was analyzed and broken up into separate activities. The time needed to perform these activities was measured. Based on linear regression analysis, for each activity, the time needed was calculated as a function of the number of slides or blocks involved. The total pathologists' time required for a range of specimens was calculated based on standard protocols and validated by comparing to actually measured workload. Cutting up, microscopic procedures and dictating turned out to be highly correlated to number of blocks and/or slides per specimen. Calculated workload per type of specimen was significantly correlated to the actually measured workload. Modeling pathologists' workload based on formulas that calculate workload per type of specimen as a function of the number of blocks and slides provides a basis for a comprehensive, yet flexible, activity-based costing system for pathology.

How molecular motors shape the flagellar beat

PubMed Central

Riedel-Kruse, Ingmar H.; Hilfinger, Andreas; Howard, Jonathon; Jülicher, Frank

2007-01-01

Cilia and eukaryotic flagella are slender cellular appendages whose regular beating propels cells and microorganisms through aqueous media. The beat is an oscillating pattern of propagating bends generated by dynein motor proteins. A key open question is how the activity of the motors is coordinated in space and time. To elucidate the nature of this coordination we inferred the mechanical properties of the motors by analyzing the shape of beating sperm: Steadily beating bull sperm were imaged and their shapes were measured with high precision using a Fourier averaging technique. Comparing our experimental data with wave forms calculated for different scenarios of motor coordination we found that only the scenario of interdoublet sliding regulating motor activity gives rise to satisfactory fits. We propose that the microscopic origin of such “sliding control” is the load dependent detachment rate of motors. Agreement between observed and calculated wave forms was obtained only if significant sliding between microtubules occurred at the base. This suggests a novel mechanism by which changes in basal compliance could reverse the direction of beat propagation. We conclude that the flagellar beat patterns are determined by an interplay of the basal properties of the axoneme and the mechanical feedback of dynein motors. PMID:19404446

Influence of Surface Texture and Roughness of Softer and Harder Counter Materials on Friction During Sliding

NASA Astrophysics Data System (ADS)

Menezes, Pradeep L.; Kishore; Kailas, Satish V.; Lovell, Michael R.

2015-01-01

Surface texture influences friction during sliding contact conditions. In the present investigation, the effect of surface texture and roughness of softer and harder counter materials on friction during sliding was analyzed using an inclined scratch testing system. In the experiments, two test configurations, namely (a) steel balls against aluminum alloy flats of different surface textures and (b) aluminum alloy pins against steel flats of different surface textures, are utilized. The surface textures were classified into unidirectionally ground, 8-ground, and randomly polished. For a given texture, the roughness of the flat surfaces was varied using grinding or polishing methods. Optical profilometer and scanning electron microscope were used to characterize the contact surfaces before and after the experiments. Experimental results showed that the surface textures of both harder and softer materials are important in controlling the frictional behavior. The softer material surface textures showed larger variations in friction between ground and polished surfaces. However, the harder material surface textures demonstrated a better control over friction among the ground surfaces. Although the effect of roughness on friction was less significant when compared to textures, the harder material roughness showed better correlations when compared to the softer material roughness.

Virtual slide telepathology workstation of the future: lessons learned from teleradiology☆

PubMed Central

Krupinski, Elizabeth A.

2013-01-01

Summary The clinical reading environment for the 21st century pathologist looks very different than it did even a few short years ago. Glass slides are quickly being replaced by digital “virtual slides,” and the traditional light microscope is being replaced by the computer display. There are numerous questions that arise however when deciding exactly what this new digital display viewing environment will be like. Choosing a workstation for daily use in the interpretation of digital pathology images can be a very daunting task. Radiology went digital nearly 20 years ago and faced many of the same challenges so there are lessons to be learned from these experiences. One major lesson is that there is no “one size fits all” workstation so users must consider a variety of factors when choosing a workstation. In this article, we summarize some of the potentially critical elements in a pathology workstation and the characteristics one should be aware of and look for in the selection of one. Issues pertaining to both hardware and software aspects of medical workstations will be reviewed particularly as they may impact the interpretation process. PMID:19552939

Efficient second-harmonic imaging of collagen in histological slides using Bessel beam excitation

NASA Astrophysics Data System (ADS)

Vuillemin, Nelly; Mahou, Pierre; Débarre, Delphine; Gacoin, Thierry; Tharaux, Pierre-Louis; Schanne-Klein, Marie-Claire; Supatto, Willy; Beaurepaire, Emmanuel

2016-07-01

Second-harmonic generation (SHG) is the most specific label-free indicator of collagen accumulation in widespread pathologies such as fibrosis, and SHG-based measurements hold important potential for biomedical analyses. However, efficient collagen SHG scoring in histological slides is hampered by the limited depth-of-field of usual nonlinear microscopes relying on focused Gaussian beam excitation. In this work we analyze theoretically and experimentally the use of Bessel beam excitation to address this issue. Focused Bessel beams can provide an axially extended excitation volume for nonlinear microscopy while preserving lateral resolution. We show that shaping the focal volume has consequences on signal level and scattering directionality in the case of coherent signals (such as SHG) which significantly differ from the case of incoherent signals (two-photon excited fluorescence, 2PEF). We demonstrate extended-depth SHG-2PEF imaging of fibrotic mouse kidney histological slides. Finally, we show that Bessel beam excitation combined with spatial filtering of the harmonic light in wave vector space can be used to probe collagen accumulation more efficiently than the usual Gaussian excitation scheme. These results open the way to SHG-based histological diagnoses.

Wear Properties of ECAP-Processed AM80 Magnesium Alloy

NASA Astrophysics Data System (ADS)

Gopi, K. R.; Shivananda Nayaka, H.; Sahu, Sandeep

2017-07-01

AM80 magnesium alloy was subjected to equal-channel angular pressing (ECAP), and microstructural evolution was studied using scanning electron microscope (SEM). Grain size was found to decrease up to 3 µm after four passes. An increase in number of ECAP passes led to a corresponding increase in hardness of the processed samples. Unprocessed and ECAP-processed samples were subjected to wear test using pin-on-disk wear test machine to study the wear behavior. Effects of varying loads (30 and 40 N) with sliding distances (2500 and 5000 m) were studied. The results showed reduction in wear mass loss for the ECAP-processed samples in comparison with unprocessed condition. Coefficient of friction (COF) was studied for different loads, and improvement in COF values was observed for ECAP-processed samples compared to unprocessed condition. Worn surfaces were studied using SEM and energy-dispersive x-ray spectrometer, and they exhibited plastic deformation, delamination, plowing, wear debris and oxidation in the sliding direction. X-ray diffraction analysis was conducted on the worn surfaces to identify the phases. It revealed the presence of magnesium oxide and magnesium aluminum oxide which led to oxidation wear in the sliding direction. Wear mechanism was found to be abrasive and oxidation wear.

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

Esgin, U.; Özyürek, D.; Kaya, H., E-mail: hasan.kaya@kocaeli.edu.tr

In the present study, wear behaviors of Monel 400, Monel 404, Monel R-405 and Monel K-500 alloys produced by Powder Metallurgy (P/M) method were investigated. These compounds prepared from elemental powders were cold-pressed (600 MPa) and then, sintered at 1150°C for 2 hours and cooled down to the room temperature in furnace environment. Monel alloys produced by the P/M method were characterized through scanning electron microscope (SEM+EDS), X-ray diffraction (XRD), hardness and density measurements. In wear tests, standard pin-on-disk type device was used. Specimens produced within four different Monel Alloys were tested under 1ms{sup −1} sliding speed, under three different loadsmore » (20N, 30N and 40N) and five different sliding distances (400-2000 m). The results show that Monel Alloys have γ matrix and that Al{sub 0,9}Ni{sub 4,22} intermetallic phase was formed in the structure. Also, the highest hardness value was measured with the Monel K-500 alloy. In wear tests, the maximum weight loss according to the sliding distance, was observed in Monel 400 and Monel 404 alloys while the minimum weight loss was achieved by the Monel K-500 alloy.« less

Efficient second-harmonic imaging of collagen in histological slides using Bessel beam excitation

PubMed Central

Vuillemin, Nelly; Mahou, Pierre; Débarre, Delphine; Gacoin, Thierry; Tharaux, Pierre-Louis; Schanne-Klein, Marie-Claire; Supatto, Willy; Beaurepaire, Emmanuel

2016-01-01

Second-harmonic generation (SHG) is the most specific label-free indicator of collagen accumulation in widespread pathologies such as fibrosis, and SHG-based measurements hold important potential for biomedical analyses. However, efficient collagen SHG scoring in histological slides is hampered by the limited depth-of-field of usual nonlinear microscopes relying on focused Gaussian beam excitation. In this work we analyze theoretically and experimentally the use of Bessel beam excitation to address this issue. Focused Bessel beams can provide an axially extended excitation volume for nonlinear microscopy while preserving lateral resolution. We show that shaping the focal volume has consequences on signal level and scattering directionality in the case of coherent signals (such as SHG) which significantly differ from the case of incoherent signals (two-photon excited fluorescence, 2PEF). We demonstrate extended-depth SHG-2PEF imaging of fibrotic mouse kidney histological slides. Finally, we show that Bessel beam excitation combined with spatial filtering of the harmonic light in wave vector space can be used to probe collagen accumulation more efficiently than the usual Gaussian excitation scheme. These results open the way to SHG-based histological diagnoses. PMID:27435390

Handling Golgi-impregnated tissue for light microscopy.

PubMed

Berbel, P J; Fairén, A

1983-08-08

The use of cyanocrylic glue to fix pieces of Golgi-stained nervous tissue on a paraffin blank is proposed for obtaining thick sections of unembedded tissue with a sliding microtome. This procedure makes correct orientation of the tissue easy during sectioning and makes it possible to obtain tissue sections quickly. The sections are flat-mounted using epoxy resin, resulting in permanent preparations with excellent optical properties and enabling further thin-sectioning for light and electron microscopic studies.

Nanoscale wear and machining behavior of nanolayer interfaces.

PubMed

Nie, Xueyuan; Zhang, Peng; Weiner, Anita M; Cheng, Yang-Tse

2005-10-01

An atomic force microscope was used to subnanometer incise a nanomultilayer to consequently expose individual nanolayers and interfaces on which sliding and scanning nanowear/machining have been performed. The letter reports the first observation on the nanoscale where (i) atomic debris forms in a collective manner, most-likely by deformation and rupture of atomic bonds, and (ii) the nanolayer interfaces possess a much higher wear resistance (desired for nanomachines) or lower machinability (not desired for nanomachining) than the layers.

Automatic microscopy for mitotic cell location.

NASA Technical Reports Server (NTRS)

Herron, J.; Ranshaw, R.; Castle, J.; Wald, N.

1972-01-01

Advances are reported in the development of an automatic microscope with which to locate hematologic or other cells in mitosis for subsequent chromosome analysis. The system under development is designed to perform the functions of: slide scanning to locate metaphase cells; conversion of images of selected cells into binary form; and on-line computer analysis of the digitized image for significant cytogenetic data. Cell detection criteria are evaluated using a test sample of 100 mitotic cells and 100 artifacts.

An initial trial of a prototype telepathology system featuring static imaging with discrete control of the remote microscope.

PubMed

Winokur, T S; McClellan, S; Siegal, G P; Reddy, V; Listinsky, C M; Conner, D; Goldman, J; Grimes, G; Vaughn, G; McDonald, J M

1998-07-01

Routine diagnosis of pathology images transmitted over telecommunications lines remains an elusive goal. Part of the resistance stems from the difficulty of enabling image selection by the remote pathologist. To address this problem, a telepathology microscope system (TelePath, TeleMedicine Solutions, Birmingham, Ala) that has features associated with static and dynamic imaging systems was constructed. Features of the system include near real time image transmission, provision of a tiled overview image, free choice of any fields at any desired optical magnification, and automated tracking of the pathologist's image selection. All commands and images are discrete, avoiding many inherent problems of full motion video and continuous remote control. A set of 64 slides was reviewed by 3 pathologists in a simulated frozen section environment. Each pathologist provided diagnoses for all 64 slides, as well as qualitative information about the system. Thirty-one of 192 diagnoses disagreed with the reference diagnosis that had been reached before the trial began. Qf the 31, 13 were deferrals and 12 were diagnoses of cases that had a deferral as the reference diagnosis. In 6 cases, the diagnosis disagreed with the reference diagnosis yielding an overall accuracy of 96.9%. Confidence levels in the diagnoses were high. This trial suggests that this system provides high-quality anatomic pathology services, including intraoperative diagnoses, over telecommunications lines.

Evaluation of Wear on Macro-Surface Textures Generated by ns Fiber Laser

NASA Astrophysics Data System (ADS)

Harish, V.; Soundarapandian, S.; Vijayaraghavan, L.; Bharatish, A.

2018-03-01

The demand for improved performance and long term reliability of mechanical systems dictate the use of advanced materials and surface engineering techniques. A small change in the surface topography can lead to substantial improvements in the tribological behaviour of the contact surfaces. One way of altering the surface topography is by surface texturing by introducing dimples or channels on the surfaces. Surface texturing is already a successful technique which finds a wide area of applications ranging from heavy industries to small scale devices. This paper reports the effect of macro texture shapes generated using a nanosecond fiber laser on wear of high carbon chromium steel used in large size bearings having rolling contacts. Circular and square shaped dimples were generated on the surface to assess the effect of sliding velocities on friction coefficient. Graphite was used as solid lubricant to minimise the effect of wear on textured surfaces. The laser parameters such as power, scan speed and passes were optimised to obtain macro circular and square dimples which was characterised using a laser confocal microscope. The friction coefficients of the circular and square dimples were observed to lie in the same range due to minimum wear on the surface. On the contrary, at medium and higher sliding velocities, square dimples exhibited lower friction coefficient values compared to circular dimples. The morphology of textured specimen was characterised using Scanning Electron Microscope.

The early study on the inspection of tongue of the traditional Chinese medicine using optical coherence tomography

NASA Astrophysics Data System (ADS)

Zhong, Hui-Qing; Zeng, Chang-Chun; Guo, Zhou-Yi; He, Yong-Hong; Wang, Rui-Kang; Liu, Song-Hao

2007-05-01

Inspection of tongue is an age-old technique used by Traditional Chinese Medicine (TCM) practitioners to determine a patient's health status. Because tongue examination is a subjective and inaccurate diagnostic method, a scientific tool which can provide objective and accurate information is needed to assist the TCM practitioners in their practice. The purpose of the study was to examine the feasibility of developing a glossoscopy from an optical coherence tomography (OCT) imaging system. In the present study, an OCT system was used to examine the tongue of the rat. After examination, the tongue was surgically removed, sectioned by a microtome and put on a glass slide for histological examination. The slides were examined under a bright-field microscope. Results of the OCT imaging studies showed that the OCT system was capable of showing the images of three distinct regions of the tongue: the tongue coating layers, the interface between the tongue coating and the tongue body, and the tongue body. It was also possible to assign an index number to each of the coating layers. When the tongue tissue was examined under a microscope, three separate regions of the tongue also were visible. Results of this pilot study shows that the OCT potentially can be developed into a glossoscopy for clinical application in TCM practice.

Fast production of microfluidic devices by CO2 laser engraving of wax-coated glass slides.

PubMed

da Costa, Eric T; Santos, Mauro S F; Jiao, Hong; do Lago, Claudimir L; Gutz, Ivano G R; Garcia, Carlos D

2016-07-01

Glass is one of the most convenient materials for the development of microfluidic devices. However, most fabrication protocols require long processing times and expensive facilities. As a convenient alternative, polymeric materials have been extensively used due their lower cost and versatility. Although CO2 laser ablation has been used for fast prototyping on polymeric materials, it cannot be applied to glass devices because the local heating causes thermal stress and results in extensive cracking. A few papers have shown the ablation of channels or thin holes (used as reservoirs) on glass but the process is still far away from yielding functional glass microfluidic devices. To address these shortcomings, this communication describes a simple method to engrave glass-based capillary electrophoresis devices using standard (1 mm-thick) microscope glass slides. The process uses a sacrificial layer of wax as heat sink and enables the development of both channels (with semicircular shape) and pass-through reservoirs. Although microscope images showed some small cracks around the channels (that became irrelevant after sealing the engraved glass layer to PDMS) the proposed strategy is a leap forward in the application of the technology to glass. In order to demonstrate the capabilities of the approach, the separation of dopamine, catechol and uric acid was accomplished in less than 100 s. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Improved microautoradiographic method to determine individual microorganisms active in substrate uptake in natural waters.

PubMed

Tabor, P S; Neihof, R A

1982-10-01

We report a method which combines epifluorescence microscopy and microautoradiography to determine both the total number of microorganisms in natural water populations and those individual organisms active in the uptake of specific substrates. After incubation with H-labeled substrate, the sample is filtered and, while still on the filter, mounted directly in a film of autoradiographic emulsion on a microscope slide. The microautoradiogram is processed and stained with acridine orange, and, subsequently, the filter is removed before microscopic observation. This novel preparation resulted in increased accuracy in direct counts made from the autoradiogram, improved sensitivity in the recognition of uptake-active (H-labeled) organisms, and enumeration of a significantly greater number of labeled organisms compared with corresponding samples prepared by a previously reported method.

Improved Microautoradiographic Method to Determine Individual Microorganisms Active in Substrate Uptake in Natural Waters

PubMed Central

Tabor, Paul S.; Neihof, Rex A.

1982-01-01

We report a method which combines epifluorescence microscopy and microautoradiography to determine both the total number of microorganisms in natural water populations and those individual organisms active in the uptake of specific substrates. After incubation with 3H-labeled substrate, the sample is filtered and, while still on the filter, mounted directly in a film of autoradiographic emulsion on a microscope slide. The microautoradiogram is processed and stained with acridine orange, and, subsequently, the filter is removed before microscopic observation. This novel preparation resulted in increased accuracy in direct counts made from the autoradiogram, improved sensitivity in the recognition of uptake-active (3H-labeled) organisms, and enumeration of a significantly greater number of labeled organisms compared with corresponding samples prepared by a previously reported method. Images PMID:16346120

A virtual microscope for academic medical education: the pate project.

PubMed

Brochhausen, Christoph; Winther, Hinrich B; Hundt, Christian; Schmitt, Volker H; Schömer, Elmar; Kirkpatrick, C James

2015-05-11

Whole-slide imaging (WSI) has become more prominent and continues to gain in importance in student teaching. Applications with different scope have been developed. Many of these applications have either technical or design shortcomings. To design a survey to determine student expectations of WSI applications for teaching histological and pathological diagnosis. To develop a new WSI application based on the findings of the survey. A total of 216 students were questioned about their experiences and expectations of WSI applications, as well as favorable and undesired features. The survey included 14 multiple choice and two essay questions. Based on the survey, we developed a new WSI application called Pate utilizing open source technologies. The survey sample included 216 students-62.0% (134) women and 36.1% (78) men. Out of 216 students, 4 (1.9%) did not disclose their gender. The best-known preexisting WSI applications included Mainzer Histo Maps (199/216, 92.1%), Histoweb Tübingen (16/216, 7.4%), and Histonet Ulm (8/216, 3.7%). Desired features for the students were latitude in the slides (190/216, 88.0%), histological (191/216, 88.4%) and pathological (186/216, 86.1%) annotations, points of interest (181/216, 83.8%), background information (146/216, 67.6%), and auxiliary informational texts (113/216, 52.3%). By contrast, a discussion forum was far less important (9/216, 4.2%) for the students. The survey revealed that the students appreciate a rich feature set, including WSI functionality, points of interest, auxiliary informational texts, and annotations. The development of Pate was significantly influenced by the findings of the survey. Although Pate currently has some issues with the Zoomify file format, it could be shown that Web technologies are capable of providing a high-performance WSI experience, as well as a rich feature set.

Molecular crowding at microtubule plus-ends acts as a physical barrier to microtubule sliding for the organization of stable anti-parallel overlaps by PRC1 and Kif4A

NASA Astrophysics Data System (ADS)

Wijeratne, Sitara; Subramanian, Radhika

The relative sliding of microtubules by motor proteins is important for the organization of specialized cellular microtubule networks. In cells, sliding filaments are likely to encounter crowded regions of microtubules, such as the plus-ends, which are densely occupied by motor and non-motor proteins. How molecular crowding impacts microtubule sliding is not well understood. Here, we reconstitute the collective activities of the non-motor protein PRC1 and the motor protein Kif4A on anti-parallel microtubules to address this question. We find that the accumulation of PRC1 and Kif4A at microtubule-plus ends (`end-tags') can act as a physical barrier to Kif4A-mediated microtubule sliding. This enables the formation of stable microtubule overlaps that persist even after the deactivation of the motor protein. Our data suggest that while end-tags stabilize anti-parallel overlaps by inhibiting relative sliding, they permit the remodeling of the microtubule bundles by external forces, as may be required for the reorganization of microtubule networks during dynamic cellular processes.

Abrasive wear behavior of in-situ RZ5-10wt%TiC composite

NASA Astrophysics Data System (ADS)

Mehra, Deepak; Mahapatra, M. M.; Harsha, S. P.

2018-05-01

RZ5 Magnesium alloys containing zinc, rare earth and zirconium are well-known to have high specific strength, good creep resistance widely used in aerospace components. The incorporation of hard ceramic strengthens RZ5 mg alloy. The RZ5-10wt%TiC composite has been fabricated in situ using RZ5 mg alloy as matrix and TiC as reinforcement by self propagating high temperature synthesis (SHS) technique. This paper investigates the abrasive wear behavior of RZ5-10wt%TiC. Tests were performed using pin-on-disc apparatus against 600 grit abrasive paper by varying the sliding distance and applied load. The results showed improvement in the wear resistance of testing composite as compared to the unreinforced RZ5 Mg alloy. The coefficient of friction and weight loss increased linearly as applied load and sliding distance increased. The field emission scanning electron microscopic (FESEM) showed dominate wear mechanisms: abrasion, ploughing grooves.

Microfabricated Fountain Pens for High-Density DNA Arrays

PubMed Central

Reese, Matthew O.; van Dam, R. Michae; Scherer, Axel; Quake, Stephen R.

2003-01-01

We used photolithographic microfabrication techniques to create very small stainless steel fountain pens that were installed in place of conventional pens on a microarray spotter. Because of the small feature size produced by the microfabricated pens, we were able to print arrays with up to 25,000 spots/cm2, significantly higher than can be achieved by other deposition methods. This feature density is sufficiently large that a standard microscope slide can contain multiple replicates of every gene in a complex organism such as a mouse or human. We tested carryover during array printing with dye solution, labeled DNA, and hybridized DNA, and we found it to be indistinguishable from background. Hybridization also showed good sequence specificity to printed oligonucleotides. In addition to improved slide capacity, the microfabrication process offers the possibility of low-cost mass-produced pens and the flexibility to include novel pen features that cannot be machined with conventional techniques. PMID:12975313

Ultrahigh interlayer friction in multiwalled boron nitride nanotubes.

PubMed

Niguès, A; Siria, A; Vincent, P; Poncharal, P; Bocquet, L

2014-07-01

Friction at the nanoscale has revealed a wealth of behaviours that depart strongly from the long-standing macroscopic laws of Amontons-Coulomb. Here, by using a 'Christmas cracker'-type of system in which a multiwalled nanotube is torn apart between a quartz-tuning-fork-based atomic force microscope (TF-AFM) and a nanomanipulator, we compare the mechanical response of multiwalled carbon nanotubes (CNTs) and multiwalled boron nitride nanotubes (BNNTs) during the fracture and telescopic sliding of the layers. We found that the interlayer friction for insulating BNNTs results in ultrahigh viscous-like dissipation that is proportional to the contact area, whereas for the semimetallic CNTs the sliding friction vanishes within experimental uncertainty. We ascribe this difference to the ionic character of the BN, which allows charge localization. The interlayer viscous friction of BNNTs suggests that BNNT membranes could serve as extremely efficient shock-absorbing surfaces.

Plasma Assisted Decontamination of Bacterial Spores

PubMed Central

Kuo, Spencer P

2008-01-01

The efficacy and mechanism of killing bacterial spores by a plasma torch is studied. Bacterial-spore (Bacillus cereus) suspension is inoculated onto glass/paper slide-coupons and desiccated into dry samples, and inoculated into well-microplate as wet sample. The exposure distance of all samples is 4 cm from the nozzle of the torch. In the experiment, paper slide-coupon is inserted inside an envelope. The kill times on spores in three types of samples are measured to be about 3, 9, and 24 seconds. The changes in the morphology and shape of still viable spores in treated wet samples are recorded by scanning electron and atomic force microscopes. The loss of appendages and exosporium in the structure and squashed/flattened cell shape are observed. The emission spectroscopy of the torch indicates that the plasma effluent carries abundant reactive atomic oxygen, which is responsible for the destruction of spores. PMID:19662115

Measurement of cell respiration and oxygenation in standard multichannel biochips using phosphorescent O2-sensitive probes.

PubMed

Kondrashina, Alina V; Papkovsky, Dmitri B; Dmitriev, Ruslan I

2013-09-07

Measurement of cell oxygenation and oxygen consumption is useful for studies of cell bioenergetics, metabolism, mitochondrial function, drug toxicity and common pathophysiological conditions. Here we present a new platform for such applications which uses commercial multichannel biochips (μ-slides, Ibidi) and phosphorescent O2 sensitive probes. This platform was evaluated with both extracellular and intracellular O2 probes, several different cell types and treatments including mitochondrial uncoupling and inhibition, depletion of extracellular Ca(2+) and inhibition of V-ATPase and histone deacetylases. The results show that compared to the standard microwell plates currently used, the μ-slide platform provides facile O2 measurements with both suspension and adherent cells, higher sensitivity and reproducibility, and faster measurement time. It also allows re-perfusion and multiple treatments of cells and multi-parametric analyses in conjunction with other probes. Optical measurements are conducted on standard fluorescence readers and microscopes.

DICOM to print, 35-mm slides, web, and video projector: tutorial using Adobe Photoshop.

PubMed

Gurney, Jud W

2002-10-01

Preparing images for publication has dealt with film and the photographic process. With picture archiving and communications systems, many departments will no longer produce film. This will change how images are produced for publication. DICOM, the file format for radiographic images, has to be converted and then prepared for traditional publication, 35-mm slides, the newest techniques of video projection, and the World Wide Web. Tagged image file format is the common format for traditional print publication, whereas joint photographic expert group is the current file format for the World Wide Web. Each medium has specific requirements that can be met with a common image-editing program such as Adobe Photoshop (Adobe Systems, San Jose, CA). High-resolution images are required for print, a process that requires interpolation. However, the Internet requires images with a small file size for rapid transmission. The resolution of each output differs and the image resolution must be optimized to match the output of the publishing medium.

A comparison of digitized frozen section and smear preparations for intraoperative neurotelepathology.

PubMed

Gould, Peter V; Saikali, Stephan

2012-01-01

Intraoperative consultations in neuropathology are often assessed by smear preparations rather than by frozen sections. Both techniques are standard practice for light microscopic examination on site, but there is little data comparing these techniques in a telepathology setting. Thirty cases of brain tumours submitted for intraoperative consultation at our institution between July and December 2010 were identified in which both frozen section and tissue smear preparations were available for digitization at 20× magnification. Slides were digitized using a Hamamatsu Nanozoomer 2.0 HT whole slide scanner, and resulting digital images were visualized at 1680 × 1050 pixel resolution with NDP. view software. The original intraoperative diagnosis was concordant with the sign out diagnosis in 29/30 cases; one tumeur was initially interpreted as a high grade glioma but proved to be a lymphoma at sign out. Digitized frozen section slides were sufficient for diagnosis at 10× magnification in 27/30 cases. Digitized tissue smears were sufficient for diagnosis at 10× magnification in 28/30 cases. In two cases tumour was present on the tissue smear but not the frozen section (one case of recurrent astrocytoma, one case of meningeal carcinomatosis). In one case of lymphoma, tumour was present on frozen section only. These discrepancies were attributed to tissue sampling rather than image quality. Examination of digitized slides at higher magnfication (20×) permitted confirmation of mitoses and Rosenthal fibers on tissue smear preparations, but did not change the primary diagnosis. Intra-slide variations in tissue thickness on smear preparations led to variable loss of focus in digitized images, but did not affect image quality in thinner areas of the smear or impede diagnosis. Digitized tissue smears are suitable for intraoperative neurotelepathology and provide comparable information to digitized frozen sections at medium power magnification.

Investigation of multi-scale flash-weakening of rock surfaces during high speed slip

NASA Astrophysics Data System (ADS)

Barbery, M. R.; Saber, O.; Chester, F. M.; Chester, J. S.

2017-12-01

A significant reduction in the coefficient of friction of rock can occur if sliding velocity approaches seismic rates as a consequence of weakening of microscopic sliding contacts by flash heating. Using a high-acceleration and -speed biaxial apparatus equipped with a high-speed Infra-Red (IR) camera to capture thermographs of the sliding surface, we have documented the heterogeneous distribution of temperature on flash-heated decimetric surfaces characterized by linear arrays of high-temperature, mm-size spots, and streaks. Numerical models that are informed by the character of flash heated surfaces and that consider the coupling of changes in temperature and changes in the friction of contacts, supports the hypothesis that independent mechanisms of flash weakening operate at different contact scales. Here, we report on new experiments that provide additional constraints on the life-times and rest-times of populations of millimeter-scale contacts. Rock friction experiments conducted on Westerly granite samples in a double-direct shear configuration achieve velocity steps from 1 mm/s to 900 mm/s at 100g accelerations over 2 mm of displacement with normal stresses of 22-36 MPa and 30 mm of displacement during sustained high-speed sliding. Sliding surfaces are machined to roughness similar to natural fault surfaces and that allow us to control the characteristics of millimeter-scale contact populations. Thermographs of the sliding surface show temperatures up to 200 C on millimeter-scale contacts, in agreement with 1-D heat conduction model estimates of 180 C. Preliminary comparison of thermal modeling results and experiment observations demonstrate that we can distinguish the different life-times and rest-times of contacts in thermographs and the corresponding frictional weakening behaviors. Continued work on machined surfaces that lead to different contact population characteristics will be used to test the multi-scale and multi-mechanism hypothesis for flash weakening during seismic slip on rough fault surfaces.

Automated Selection of Hotspots (ASH): enhanced automated segmentation and adaptive step finding for Ki67 hotspot detection in adrenal cortical cancer.

PubMed

Lu, Hao; Papathomas, Thomas G; van Zessen, David; Palli, Ivo; de Krijger, Ronald R; van der Spek, Peter J; Dinjens, Winand N M; Stubbs, Andrew P

2014-11-25

In prognosis and therapeutics of adrenal cortical carcinoma (ACC), the selection of the most active areas in proliferative rate (hotspots) within a slide and objective quantification of immunohistochemical Ki67 Labelling Index (LI) are of critical importance. In addition to intratumoral heterogeneity in proliferative rate i.e. levels of Ki67 expression within a given ACC, lack of uniformity and reproducibility in the method of quantification of Ki67 LI may confound an accurate assessment of Ki67 LI. We have implemented an open source toolset, Automated Selection of Hotspots (ASH), for automated hotspot detection and quantification of Ki67 LI. ASH utilizes NanoZoomer Digital Pathology Image (NDPI) splitter to convert the specific NDPI format digital slide scanned from the Hamamatsu instrument into a conventional tiff or jpeg format image for automated segmentation and adaptive step finding hotspots detection algorithm. Quantitative hotspot ranking is provided by the functionality from the open source application ImmunoRatio as part of the ASH protocol. The output is a ranked set of hotspots with concomitant quantitative values based on whole slide ranking. We have implemented an open source automated detection quantitative ranking of hotspots to support histopathologists in selecting the 'hottest' hotspot areas in adrenocortical carcinoma. To provide wider community easy access to ASH we implemented a Galaxy virtual machine (VM) of ASH which is available from http://bioinformatics.erasmusmc.nl/wiki/Automated_Selection_of_Hotspots . The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_216.

Why is there a large submarine landslide in the Jan Mayen Ridge, north Norway?

NASA Astrophysics Data System (ADS)

Kawamura, Kiichiro; Sverre Laberg, Jan

2013-04-01

This paper deals with the formation process/mechanism of a large submarine landslide in the Jan Mayen Ridge. The Jan Mayen Ridge, being a continental sliver, is ~250 km long in N-S direction with a flat plateau of ~800 m in water depth standing on an abyssal plane of 2500-3000 m in water depth. There is only a large submarine landslide scar of ~50 km wide in the central east side. In the central east side, the internal geologic architecture is characterized by an Eocene-Oligocene sedimentary sequence, which tilts eastward. This sedimentary sequence is cut by large normal faults, that have formed by the spread of the Norwegina-Greenland Sea since 20 Ma. The wasted mass of the large submarine landslide could slip down along the bedding plane and/or the normal faults dipping to east. Thus, the slide form a big spoon-shaped basin. The slide scar was collapsed retrogressively to make a small spoon-shaped basin on the upper part of the big basin. There are long channels from the retrogressive slide scars to the lower basin. The retrogressive slides would continue to discharge progressively gravity flows to make the long channels on the basin after the large submarine landslide occurred. On contrary to the slide region, the sedimentary sequence has a large anticline in an east foot of the ridge in other regions. This anticline could be an obstruction to a large submarine landslide. Thus, the geologic architecture plays an important role in the formation mechanism of a large submarine landslides in the Jan Mayen Ridge.

Opioid Abuse after TBI

DTIC Science & Technology

2015-09-01

hippocampal formation (Paxinos and Watson, 2005). The sections were mounted on 1% gelatin -coated slides and stored at -20°C until further histological... drying at room temperature overnight. Finally, sections were rinsed in xylene (2 times for 5 min) and coverslipped with DPX mounting media (Electron...0.1M phosphate buffered saline (3 x 5 min) and 0.1M phosphate buffer (3 x 5 min) and slides were allowed to dry for one hour before being

Using sub-micron silver-nanoparticle based films to counter biofilm formation by Gram-negative bacteria

NASA Astrophysics Data System (ADS)

Gillett, A. R.; Baxter, S. N.; Hodgson, S. D.; Smith, G. C.; Thomas, P. J.

2018-06-01

Composite films comprised of silver nanoparticles (AgNPs) grown using a low-cost straightforward chemical bath based method have been deposited on glass microscope slides to investigate their potential as a sacrificial antibacterial coating. The as-deposited films have been characterised using scanning electron microscopy (SEM) and optical profilometry. These suggested that the films were relatively uniform in coverage. Chemical composition of the AgNP films has been studied by using X-ray photoelectron spectroscopy (XPS). The XPS analysis indicated that the Ag was in a metallic form able to sustain plasmon behaviour, and that low levels of residual nanoparticle precursors were present. Particle size was characterised using transmission electron microscopy (TEM) which showed an average particle size of 10.6 nm. The effectiveness of the films as an antibacterial coating was tested against Escherichia coli. The AgNP film was determined to be effective in the killing of E. coli cells over a 24 h period when compared to equivalent samples that contained no silver. Of particular note was that only minimal bacterial growth was detected over the first 12 h of testing, up to 78.6 times less than the control samples, suggesting the film is very efficient at slowing initial biofilm formation. The use of AgNP based films that have been synthesised using a novel low-cost, low-temperature and highly upscalable method is demonstrated as a promising solution for the deployment of silver as an effective sacrifical antimicrobial coating to counter the formation of potentially hazardous Gram negative biofilms.

Slide-induced waves, seiching and ground fracturing caused by the earthquake of March 27, 1964 at Kenai Lake, Alaska: Chapter A in The Alaska earthquake, March 27, 1964: regional effects

USGS Publications Warehouse

McCulloch, David S.

1966-01-01

The March 27, 1964, earthquake dislodged slides from nine deltas in Kenai Lake, south-central Alaska. Sliding removed protruding parts of deltas-often the youngest parts-and steepened delta fronts, increasing the chances of further sliding. Fathograms show that debris from large slides spread widely over the lake floor, some reaching the toe of the opposite shore; at one place debris traveled 5,000 feet over the horizontal lake floor. Slides generated two kinds of local waves: a backfill and far-shore wave. Backfill waves were formed by water that rushed toward the delta to fill the void left by the sinking slide mass, overtopped the slide scrap, and came ashore over the delta. Some backfill waves had runup heights of 30 feet and ran inland more than 300 feet, uprooting and breaking off large trees. Far-shore waves hit the shore opposite the slides. They were formed by slide debris that crossed the lake floor and forced water ahead of it, which then ran up the opposite slope, burst above the lake surface, and struck the shore. One far-shore wave had a runup height of 72 feet. Kenai Lake was tilted and seiched; a power spectrum analysis of a limnogram shows a wave having the period of the calculated uninodal seiche (36 minutes) and several shorter period waves. In constricted and shallow reaches, waves caused by seiching had 20- and 30-foot runup heights. Deep lateral spreading of sediments toward delta margins displaced deeply driven railroad-bridge piles, and set up stress fields in the surface sediments which resulted in the formation of many shear and some tension fractures on the surface of two deltas.

Effect of surface mobility on the particle sliding along a bubble or a solid sphere.

PubMed

Wang, Weixing; Zhou, Zhiang; Nandakumar, K; Xu, Zhenghe; Masliyah, Jacob H

2003-03-01

The sliding velocity of glass beads on a spherical surface, made either of an air bubble or of a glass sphere held stationary, is measured to investigate the effect of surface mobility on the particle sliding velocity. The sliding process is recorded with a digital camera and analyzed frame by frame. The sliding glass bead was found to accelerate with increasing angular position on the collector's surface. It reaches a maximum velocity at an angular position of about 100 degrees and then, under certain conditions, the glass bead leaves the surface of the collector. The sliding velocity of the glass bead depends strongly on the surface mobility of a bubble, decreasing with decreasing surface mobility. By a mobile surface we mean one which cannot set up resistive forces to an applied stress on the surface. The sliding velocity on a rigid surface, such as a glass sphere, is much lower than that on a mobile bubble surface. The sliding velocity can be described through a modified Stokes equation. A numerical factor in the modified Stokes equation is determined by fitting the experimental data and is found to increase with decreasing surface mobility. Hydrophobic glass beads sliding on a hydrophobic glass sphere were found to stick at the point of impact without sliding if the initial angular position of the impact is less than some specific angle, which is defined as the critical sticking angle. The sticking of the glass beads can be attributed to the capillary contracting force created by the formation of a cavity due to spontaneous receding of the nonwetting liquid from the contact zone. The relationship between the critical sticking angle and the particle size is established based on the Yushchenko [J. Colloid Interface Sci. 96 (1983) 307] analysis.

Three-dimensional digital breast histopathology imaging

NASA Astrophysics Data System (ADS)

Clarke, G. M.; Peressotti, C.; Mawdsley, G. E.; Eidt, S.; Ge, M.; Morgan, T.; Zubovits, J. T.; Yaffe, M. J.

2005-04-01

We have developed a digital histology imaging system that has the potential to improve the accuracy of surgical margin assessment in the treatment of breast cancer by providing finer sampling and 3D visualization. The system is capable of producing a 3D representation of histopathology from an entire lumpectomy specimen. We acquire digital photomicrographs of a stack of large (120 x 170 mm) histology slides cut serially through the entire specimen. The images are then registered and displayed in 2D and 3D. This approach dramatically improves sampling and can improve visualization of tissue structures compared to current, small-format histology. The system consists of a brightfield microscope, adapted with a freeze-frame digital video camera and a large, motorized translation stage. The image of each slide is acquired as a mosaic of adjacent tiles, each tile representing one field-of-view of the microscope, and the mosaic is assembled into a seamless composite image. The assembly is done by a program developed to build image sets at six different levels within a multiresolution pyramid. A database-linked viewing program has been created to efficiently register and display the animated stack of images, which occupies about 80 GB of disk space per lumpectomy at full resolution, on a high-resolution (3840 x 2400 pixels) colour monitor. The scanning or tiling approach to digitization is inherently susceptible to two artefacts which disrupt the composite image, and which impose more stringent requirements on system performance. Although non-uniform illumination across any one isolated tile may not be discernible, the eye readily detects this non-uniformity when the entire assembly of tiles is viewed. The pattern is caused by deficiencies in optical alignment, spectrum of the light source, or camera corrections. The imaging task requires that features as small as 3.2 &mum in extent be seamlessly preserved. However, inadequate accuracy in positioning of the translation stage produces visible discontinuities between adjacent features. Both of these effects can distract the viewer from the perception of diagnostically important features. Here we describe the system design and discuss methods for the correction of these artefacts. In addition, we outline our approach to rendering the processing and display of these large images computationally feasible.

Optical diagnostic techniques in tribological analysis: Applications to wear film characterization, solid lubricant chemical transition, and electrical sliding contacts

NASA Astrophysics Data System (ADS)

Windom, Bret C.

Friction and wear have undisputedly huge macroscopic effects on the cost and lifetime of many mechanical systems. The cost to replace parts and the cost to overcome the energy losses associated with friction, although small in nature, can be enormous over long operating times. The understanding of wear and friction begins with the understanding of the physics and chemistry between the reacting surfaces on a microscopic level. Light as a diagnostic tool is a good candidate to perform the very sensitive microscopic measurements needed to help understand the fundamental science occurring in friction/wear systems. Light's small length scales provide the capabilities to characterize very local surface phenomena, including thin transfer films and surface chemical transitions. Light-based diagnostic techniques provide nearly instantaneous results, enabling one to make in situ/real time measurements which could be used to track wear events and associated chemical kinetics. In the present study, two optical diagnostic techniques were investigated for the analysis of tribological systems. The first technique employed was Raman spectroscopy. Raman spectroscopy was investigated as a possible means for in situ measurement of thin transfer films in order to track the wear kinetics and structural transitions of bulk polymers. A micro-Raman system was designed, built, and characterized to track fresh wear films created from a pin-on-disk tribometer. The system proved capable of characterizing and tracking wear film thicknesses of ˜2 mum and greater. In addition, the system provided results indicating structural changes in the wear film as compared to the bulk when sliding speeds were increased. The spectral changes due to the altering of molecular vibrations can be attributed to the increase in temperature during high sliding speeds. Raman spectroscopy was also used to characterize the oxidation of molybdenum disulphide, a solid lubricant used in many applications, including high vacuum sliding. Resonance Raman effects were observed when an excitation wavelength of 632.8 nm was used. Raman spectroscopy was carried out on amorphous MoS2 while its temperature was increased to track the thermally induced oxidation of the MoS2 surface. In addition, other forms of MoS2 were investigated through Raman spectroscopy in which key distinctions between spectra were made. The second technique employed was atomic emission spectroscopy (AES) used to measure constituent species present in arcs created during electrical sliding contacts. Spectra indicated the presence of copper and zinc in the arcs created between copper fiber bundled brushes and a copper rotor. Atomic emission was used to measure the arc duration with a photo-multiplier tube (PMT) while the collected spectra were processed to assess arc temperature. The results suggest arcing in high-current electrical sliding contacts may be at least partially responsible for the high asymmetrical wear measured during tribology tests.

Anti-nuclear antibody screening using HEp-2 cells.

PubMed

Buchner, Carol; Bryant, Cassandra; Eslami, Anna; Lakos, Gabriella

2014-06-23

The American College of Rheumatology position statement on ANA testing stipulates the use of IIF as the gold standard method for ANA screening(1). Although IIF is an excellent screening test in expert hands, the technical difficulties of processing and reading IIF slides--such as the labor intensive slide processing, manual reading, the need for experienced, trained technologists and the use of dark room--make the IIF method difficult to fit in the workflow of modern, automated laboratories. The first and crucial step towards high quality ANA screening is careful slide processing. This procedure is labor intensive, and requires full understanding of the process, as well as attention to details and experience. Slide reading is performed by fluorescent microscopy in dark rooms, and is done by trained technologists who are familiar with the various patterns, in the context of cell cycle and the morphology of interphase and dividing cells. Provided that IIF is the first line screening tool for SARD, understanding the steps to correctly perform this technique is critical. Recently, digital imaging systems have been developed for the automated reading of IIF slides. These systems, such as the NOVA View Automated Fluorescent Microscope, are designed to streamline the routine IIF workflow. NOVA View acquires and stores high resolution digital images of the wells, thereby separating image acquisition from interpretation; images are viewed an interpreted on high resolution computer monitors. It stores images for future reference and supports the operator's interpretation by providing fluorescent light intensity data on the images. It also preliminarily categorizes results as positive or negative, and provides pattern recognition for positive samples. In summary, it eliminates the need for darkroom, and automates and streamlines the IIF reading/interpretation workflow. Most importantly, it increases consistency between readers and readings. Moreover, with the use of barcoded slides, transcription errors are eliminated by providing sample traceability and positive patient identification. This results in increased patient data integrity and safety. The overall goal of this video is to demonstrate the IIF procedure, including slide processing, identification of common IIF patterns, and the introduction of new advancements to simplify and harmonize this technique.

A pilot training manual for the terminal configured vehicle electronic attitude director indicator

NASA Technical Reports Server (NTRS)

Gandelman, J.

1980-01-01

A hard copy version is presented of a 28-minute, 90 slide audiovisual program which provides the basic instructional format for introduction to the terminal configured vehicle electronic attitude director indicator (EADI) and the strategy for learning the symbols used on the EADI and their interpretation. The basic strategy is to start with known symbols and then introduce all new symbols with emphasis appropriate to their complexity and frequency of use. The upper half of each page of the manual contains a reproduction of the slide. The text associated with the slide is found on the lower half of each page and is recorded on audio tape.

Reliability of rapid diagnostic test for diagnosing peripheral and placental malaria in an area of unstable malaria transmission in Eastern Sudan

PubMed Central

2013-01-01

Background Diagnosing Plasmodium falciparum malaria during pregnancy is a great challenge for clinicians because of the low density of parasites in the peripheral blood and parasite sequestration in the placenta. Nevertheless, few data on the use of malaria rapid diagnostic test (RDT) during pregnancy have been published. Methods P. falciparum infections were assessed in 156 febrile pregnant women by microscopic examination of their blood smears and by RDT and polymerase chain reactions (PCR). In addition, 150 women were assessed at the time of delivery by microscopy, RDT, PCR and placental histology investigations. The study was conducted at the Gadarif Hospital, Eastern Sudan. The SD Bioline P. f / P. v (Bio Standard Diagnostics, Gurgaon, Korea) RDT kit was evaluated in this study. Results Among the febrile pregnant women, 17 (11.0%), 26 (16.7%) and 18 (11.5%) positive cases of P. falciparum were detected by microscopy, RDT, and PCR, respectively. The sensitivity and specificity of the microscopy was 94.4% and 100%, respectively. The corresponding values for RDT evaluation were 83.3% and 92.0%, as compared with PCR as the gold standard. While there were no detected cases of malaria by microscopic examination of blood smears, 27 (18.0%), 21(14.0%) and 46 (30.7%) out of the 150 placentae investigated had P. falciparum as determined by RDT, PCR, and histology, respectively. The sensitivity and specificity for RDT was 17.4% and 81.7%, respectively. The corresponding values for PCR were 6.5% and 82.7%, where histology was used as the gold standard. Conclusions The RDT kit used in this study has poor performance for peripheral and placental P. falciparum malaria detection in this setting. Virtual slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1092363465928479 PMID:23587371

Cesarean scar pregnancy and early placenta accreta share common histology.

PubMed

Timor-Tritsch, I E; Monteagudo, A; Cali, G; Palacios-Jaraquemada, J M; Maymon, R; Arslan, A A; Patil, N; Popiolek, D; Mittal, K R

2014-04-01

To determine, by evaluation of histological slides, images and descriptions of early (second-trimester) placenta accreta (EPA) and placental implantation in cases of Cesarean scar pregnancy (CSP), whether these are pathologically indistinguishable and whether they both represent different stages in the disease continuum leading to morbidly adherent placenta in the third trimester. The database of a previously published review of CSP and EPA was used to identify articles with histopathological descriptions and electronic images for pathological review. When possible, microscopic slides and/or paraffin blocks were obtained from the original researchers. We also included from our own institutions cases of CSP and EPA for which pathology specimens were available. Two pathologists examined all the material independently and, blinded to each other's findings, provided a pathological diagnosis based on microscopic appearance. Interobserver agreement in diagnosis was determined. Forty articles were identified, which included 31 cases of CSP and 13 cases of EPA containing histopathological descriptions and/or images of the pathology. We additionally included six cases of CSP and eight cases of EPA from our own institutions, giving a total of 58 cases available for histological evaluation (37 CSP and 21 EPA) containing clear definitions of morbidly adherent placenta. In the 29 cases for which images/slides were available for histopathological evaluation, both pathologists attested to the various degrees of myometrial and/or scar tissue invasion by placental villi with scant or no intervening decidua, consistent with the classic definition of morbidly adherent placenta. Based on the reviewed material, cases with a diagnosis of EPA and those with a diagnosis of CSP showed identical histopathological features. Interobserver correlation was high (kappa = 0.93). EPA and placental implantation in CSP are histopathologically indistinguishable and may represent different stages in the disease continuum leading to morbidly adherent placenta in the third trimester. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.

Use of virtual slide system for quick frozen intra-operative telepathology diagnosis in Kyoto, Japan.

PubMed

Tsuchihashi, Yasunari; Takamatsu, Terumasa; Hashimoto, Yukimasa; Takashima, Tooru; Nakano, Kooji; Fujita, Setsuya

2008-07-15

We started to use virtual slide (VS) and virtual microscopy (VM) systems for quick frozen intra-operative telepathology diagnosis in Kyoto, Japan. In the system we used a digital slide scanner, VASSALO by CLARO Inc., and a broadband optic fibre provided by NTT West Japan Inc. with the best effort capacity of 100 Mbps. The client is the pathology laboratory of Yamashiro Public Hospital, one of the local centre hospitals located in the south of Kyoto Prefecture, where a full-time pathologist is not present. The client is connected by VPN to the telepathology centre of our institute located in central Kyoto. As a result of the recent 15 test cases of VS telepathology diagnosis, including cases judging negative or positive surgical margins, we could estimate the usefulness of VS in intra-operative remote diagnosis. The time required for the frozen section VS file making was found to be around 10 min when we use x10 objective and if the maximal dimension of the frozen sample is less than 20 mm. Good correct focus of VS images was attained in all cases and all the fields of each tissue specimen. Up to now the capacity of best effort B-band appears to be sufficient to attain diagnosis on time in intra-operation. Telepathology diagnosis was achieved within 5 minutes in most cases using VS viewer provided by CLARO Inc. The VS telepathology system was found to be superior to the conventional still image telepathology system using a robotic microscope since in the former we can observe much greater image information than in the latter in a certain limited time of intra-operation and in the much more efficient ways. In the near future VS telepathology will replace conventional still image telepathology with a robotic microscope even in quick frozen intra-operative diagnosis.

Use of virtual slide system for quick frozen intra-operative telepathology diagnosis in Kyoto, Japan

PubMed Central

Tsuchihashi, Yasunari; Takamatsu, Terumasa; Hashimoto, Yukimasa; Takashima, Tooru; Nakano, Kooji; Fujita, Setsuya

2008-01-01

We started to use virtual slide (VS) and virtual microscopy (VM) systems for quick frozen intra-operative telepathology diagnosis in Kyoto, Japan. In the system we used a digital slide scanner, VASSALO by CLARO Inc., and a broadband optic fibre provided by NTT West Japan Inc. with the best effort capacity of 100 Mbps. The client is the pathology laboratory of Yamashiro Public hospital, one of the local centre hospitals located in the south of Kyoto Prefecture, where a fulltime pathologist is not present. The client is connected by VPN to the telepathology centre of our institute located in central Kyoto. As a result of the recent 15 test cases of VS telepathology diagnosis, including cases judging negative or positive surgical margins, we could estimate the usefulness of VS in intra-operative remote diagnosis. The time required for the frozen section VS file making was found to be around 10 min when we use ×10 objective and if the maximal dimension of the frozen sample is less than 20 mm. Good correct focus of VS images was attained in all cases and all the fields of each tissue specimen. Up to now the capacity of best effort B-band appears to be sufficient to attain diagnosis on time in intra-operation. Telepathology diagnosis was achieved within 5 minutes in most cases using VS viewer provided by CLARO Inc. The VS telepathology system was found to be superior to the conventional still image telepathology system using a robotic microscope since in the former we can observe much greater image information than in the latter in a certain limited time of intra-operation and in the much more efficient ways. In the near future VS telepathology will replace conventional still image telepathology with a robotic microscope even in quick frozen intra-operative diagnosis. PMID:18673520

Deformation and stabilisation mechanisms of slow rock slides in crystalline bedrock

NASA Astrophysics Data System (ADS)

Zangerl, C.; Prager, C.

2009-04-01

Deep-seated rock slides are slope instabilities which are characterised by deformation along one or several shear zones where most of the measured total slope displacement localizes. Generally, a high danger potential is given when rock slides fail in a rapid manner characterised by very high sliding velocities and/or when they develop into long run-out rock avalanches. However several field surveys and deformation monitoring data show that numerous deep-seated rock slides do not fail in a high velocity regime. In fact, many slides creep downwards at rates of some centimetres per year or even less and do not show any evidence for non-reversible acceleration in the past or in the future. Furthermore some of these slope instabilities are actually inactive (dormant) or have even reached a stabilised final state. Deformation monitoring on active rock slides show that acceleration phases characterised by velocities up to meters per day can occur. The trigger for these phases can be manifold and include heavy rainfall, snow melt, water level fluctuations of reservoirs at the slope foot, changes in the slope's equilibrium state due to antecedent slow creeping processes, changes in the material behaviour within the sliding zone, erosion along the foot of the slope, etc. Whereas the role of these triggers in promoting phases of acceleration are generally understood, the same can not be said regarding the kinematics and dynamic processes/mechanisms by which rock slide masses re-stabilise once the trigger impetus has been removed. In the context of this study the term "stabilisation" is used for rock slides which decelerate from high velocities to slow base activities or even stop moving after a certain amount of displacement. Given that reliable rock slide forecasts require the fundamental understanding of possible slope stabilisation mechanisms this study focuses on field-based and numerically obtained key-properties which influence the long-term slope deformation behaviour. On a regional scale several valleys located in amphibolites, ortho- and paragneisses of the Ötztal-Stubai crystalline basement (i.e. Kaunertal, Pitztal, Ötztal, Lüsenstal, all located in North Tyrol, Austria) were investigated. Therefore geological and morphological basis data were compiled and re-evaluated, remote sensing methods (i.e. airborne laser scanning terrain models and orthofotos) applied and field mapping campaigns performed. On a local scale several rock slides were investigated and analysed in high detail with regard to their lithological and structural inventory, geometry of sliding masses and -zones, failure mechanisms, kinematics and temporal deformation characteristics. Field data clearly show that competent rock masses, e.g. orthogneisses and amphibolites, are affected by rapid failure events and therefore are characterised by "brittle" rock mass behaviour. In contrast, the majority of the slowly moving and "self-stabilising" rock slides are located totally or partly in mica-rich incompetent crystalline rock masses, e.g. paragneisses and micaschists, and are characterised by moderately dipping sliding zones. Apart from a causal lithological influence, numerous field observations demonstrate a major influence of pre-existing geological structures on the formation and deformation behaviour of these rock slides. The nature of rock slides implies that the temporal deformation behaviour is primarily dominated by two key-features of the sliding zone i.e. the mechanical properties (shear strain strengthening or weakening) and the effective in-situ stresses. The in-situ stresses along a sliding zone are influenced by the geometry of both the sliding mass and sliding zone, the internal deformation of the sliding mass and the pore pressures. All these properties can vary during progressive shear displacements. Especially large shear displacements in the range of tens to hundreds of metres along a distinct sliding zone can cause significant in-situ stress changes which in turn may influence the slope deformation behaviour and stabilisation mechanisms. In order to study these processes for selected case studies in paragneissic rock masses the impact of the sliding mass geometry and sliding zone shape on the in-situ stresses has been investigated by applying the discrete element method. This numerical approach enables the simulation of large shear displacements and complex block assembly interactions. Results show that slope stabilisation can be achieved when the dip angle of the sliding zone flattens downslope. In this case and after a certain amount of displacement the lower part of the rock slide mass reaches stable slope conditions (shear strength of the sliding zone material exceeds the shear stress acting on the sliding zone) and acts as a resisting mass for the still unstable upper part of the slope. Furthermore numerical models show that secondary slides at the lower part of the slope have a similar effect. In both case cases the observed slope stabilisation can be clearly attributed to the formation of natural buttressing masses at the toe.

Field evaluation of the Meade Readiview handheld microscope for diagnosis of intestinal schistosomiasis in Ugandan school children.

PubMed

Stothard, J Russell; Kabatereine, Narcis B; Tukahebwa, Edridah M; Kazibwe, Francis; Mathieson, William; Webster, Joanne P; Fenwick, Alan

2005-11-01

A novel, inexpensive handheld microscope, the Meade Readiview, was evaluated for field diagnosis of intestinal schistosomiasis by comparison of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) against conventional compound microscopy as part of a parasitologic survey in nine sentinel schools and a rapid mapping survey across 22 schools in Uganda. Fecal smears from 685 primary school children were examined and the overall prevalence of Schistosoma mansoni was 45%. However, prevalence by school ranged widely from 0% to 100%. For individual diagnosis the Readiview had a sensitivity of 85%, a specificity of 96%, a PPV of 95%, and an NPV of 88%. Due to the poorer movement control of the glass slide on the Readiview stage, fecal smears with less than four eggs could be overlooked. At the highest magnification (160x), egg-like objects could be confounding. Estimating prevalence by school was usually within +/- 7% of that of conventional microscopy. Since the Readiview is more robust and portable, both in size and weight, and one-tenth as expensive as the traditional compound microscope, a change in the logistics and costs associated with field infection surveillance is possible. This inexpensive microscope is a pragmatic alternative to the compound microscope. It could play an important role in the collection of prevalence data to better guide anthelmintic drug delivery and also empower the diagnostic capacity of peripheral health centers where compound microscopes are few or absent.

Sliding mode control of electromagnetic tethered satellite formation

NASA Astrophysics Data System (ADS)

Hallaj, Mohammad Amin Alandi; Assadian, Nima

2016-08-01

This paper investigates the control of tethered satellite formation actuated by electromagnetic dipoles and reaction wheels using the robust sliding mode control technique. Generating electromagnetic forces and moments by electric current coils provides an attractive control actuation alternative for tethered satellite system due to the advantages of no propellant consumption and no obligatory rotational motion. Based on a dumbbell model of tethered satellite in which the flexibility and mass of the tether is neglected, the equations of motion in Cartesian coordinate are derived. In this model, the J2 perturbation is taken into account. The far-field and mid-field models of electromagnetic forces and moments of two satellites on each other and the effect of the Earth's magnetic field are presented. A robust sliding mode controller is designed for precise trajectory tracking purposes and to deal with the electromagnetic force and moment uncertainties and external disturbances due to the Earth's gravitational and magnetic fields inaccuracy. Numerical simulation results are presented to validate the effectiveness of the developed controller and its superiority over the linear controller.

Research Instruments

NASA Technical Reports Server (NTRS)

1992-01-01

The GENETI-SCANNER, newest product of Perceptive Scientific Instruments, Inc. (PSI), rapidly scans slides, locates, digitizes, measures and classifies specific objects and events in research and diagnostic applications. Founded by former NASA employees, PSI's primary product line is based on NASA image processing technology. The instruments karyotype - a process employed in analysis and classification of chromosomes - using a video camera mounted on a microscope. Images are digitized, enabling chromosome image enhancement. The system enables karyotyping to be done significantly faster, increasing productivity and lowering costs. Product is no longer being manufactured.

Finite Element Simulation Methods for Dry Sliding Wear

DTIC Science & Technology

2008-03-27

effects of wear only occur on a microscopic level (3; 14; 17). A third reason that wear is not well understood is that it involves many different...material or one with a higher coefficient of friction there will be more of a problem with high pressure points. A third possibility is to spread the...For the local model the rail is modeled as a deformable body , and a small, 1 mm, square is taken from the slipper as the submodel. 5.2 The Global

Descriptions of Zavortinkius, a New Subgenus of Aedes, and the Eleven Included Species from the Afrotropical Region (Diptera: Culicidae)

DTIC Science & Technology

1999-01-01

pollinctor). Aedes pollinctor is resurrected from synonymy with Ae. longipalpis and a lectotype is designated . Aedes longipalpis sensu lato is defined as a...Aedes pollinctor (males only) is herein resurrected from synonymy and a lectotype is designated ; Graham’s ( 19 1 Oa) two female syntypes are specimens...mounted on microscope slides), possess the same collection data on their labels as the holotype except the collection numbers and type designations

Enzyme-free Detection of Hydrogen Peroxide from Cerium Oxide Nanoparticles Immobilized on Poly(4-vinylpyridine) Self-Assembled Monolayers

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

Gaynor, James D.; Karakoti, Ajay S.; Inerbaev, Talgat

2013-05-02

A single layer of oxygen-deficient cerium oxide nanoparticles (CNPs) are immobilized on microscopic glass slide using poly(4-vinylpyridine) (PVP) self-assembled monolayers (SAMs). A specific colorimetric property of CNPs when reacted with hydrogen peroxide allows for the direct, single-step peroxide detection which can be used in medical diagnosis and explosives detection. Multiple PVP-CNP immobilized layers improve sensitivity of detection and the sensor can be regenerated for reuse.

Structure formation of 5083 alloy during friction stir welding

NASA Astrophysics Data System (ADS)

Zaikina, A. A.; Kolubaev, A. V.; Sizova, O. V.; Ivanov, K. V.; Filippov, A. V.; Kolubaev, E. A.

2017-12-01

This paper provides a comparative study of structures obtained by friction stir welding and sliding friction of 5083 Al alloy. Optical and electron microscopy reveals identical fine-grained structures with a grain size of ˜5 µm both in the weld nugget zone and subsurface layer in friction independently of the initial grain size of the alloy. It has been suggested that the grain boundary sliding is responsible for the specific material flow pattern in both techniques considered.

Integral sliding mode-based attitude coordinated tracking for spacecraft formation with communication delays

NASA Astrophysics Data System (ADS)

Zhang, Jian; Hu, Qinglei; Xie, Wenbo

2017-11-01

This paper investigates the attitude coordinated tracking control for a group of rigid spacecraft under directed communication topology, in which inertia uncertainties, external disturbances, input saturation and constant time-delays between the formation members are handled. Initially, the nominal system with communication delays is studied. A delay-dependent controller is proposed by using Lyapunov-Krasovskii function and sufficient condition for system stability is derived. Then, an integral sliding manifold is designed and adaptive control approach is employed to deal with the total perturbation. Meanwhile, the boundary layer method is introduced to alleviate the unexpected chattering as system trajectories cross the switching surface. Finally, numerical simulation results are presented to validate the effectiveness and robustness of the proposed control strategy.

Formation of nano-laminated structures in a dry sliding wear-induced layer under different wear mechanisms of 20CrNi2Mo steel

NASA Astrophysics Data System (ADS)

Yin, Cun-hong; Liang, Yi-long; Jiang, Yun; Yang, Ming; Long, Shao-lei

2017-11-01

The microstructures of 20CrNi2Mo steel underneath the contact surface were examined after dry sliding. Scanning Electronic Microscopy (SEM), Transmission Electron Microscopy (TEM), Electron Backscattered Diffraction (EBSD) and an ultra-micro-hardness tester were used to characterize the worn surface and dry sliding wear-induced layer. Martensite laths were ultra-refined due to cumulative strains and a large strain gradient that occurred during cyclic loading in wear near the surface. The microstructure evolution in dominant abrasive wear differs from that in adhesive wear. In dominant abrasive wear, only bent martensite laths with high-density deformation dislocations were observed. In contrast, in dominant adhesive wear, gradient structures were formed along the depth from the wear surface. Cross-sectional TEM foils were prepared in a focused ion beam (FIB) to observe the gradient structures in a dry sliding wear-induced layer at depths of approximately 1-5 μm and 5-20 μm. The gradient structures contained nano-laminated structures with an average thickness of 30-50 nm and bent martensite laths. We found that the original martensite laths coordinated with the strain energy and provided origin boundaries for the formation of gradient structures. Geometrically necessary boundaries (GNBs) and isolated dislocation boundaries (IDBs) play important roles in forming the nano-laminated structures.

Formative Assessment Probes: Representing Microscopic Life

ERIC Educational Resources Information Center

Keeley, Page

2011-01-01

This column focuses on promoting learning through assessment. The author discusses the formative assessment probe "Pond Water," which reveals how elementary children will often apply what they know about animal structures to newly discovered microscopic organisms, connecting their knowledge of the familiar to the unfamiliar through…

Combined reflection and transmission microscope for telemedicine applications in field settings.

PubMed

Biener, Gabriel; Greenbaum, Alon; Isikman, Serhan O; Lee, Kelvin; Tseng, Derek; Ozcan, Aydogan

2011-08-21

We demonstrate a field-portable upright and inverted microscope that can image specimens in both reflection and transmission modes. This compact and cost-effective dual-mode microscope weighs only ∼135 grams (<4.8 ounces) and utilizes a simple light emitting diode (LED) to illuminate the sample of interest using a beam-splitter cube that is positioned above the object plane. This LED illumination is then partially reflected from the sample to be collected by two lenses, creating a reflection image of the specimen onto an opto-electronic sensor-array that is positioned above the beam-splitter cube. In addition to this, the illumination beam is also partially transmitted through the same specimen, which then casts lensfree in-line holograms of the same objects onto a second opto-electronic sensor-array that is positioned underneath the beam-splitter cube. By rapid digital reconstruction of the acquired lensfree holograms, transmission images (both phase and amplitude) of the same specimen are also created. We tested the performance of this field-portable microscope by imaging various micro-particles, blood smears as well as a histopathology slide corresponding to skin tissue. Being compact, light-weight and cost-effective, this combined reflection and transmission microscope might especially be useful for telemedicine applications in resource limited settings. This journal is © The Royal Society of Chemistry 2011

Micro patterned surfaces: an effective tool for long term digital holographic microscopy cell imaging

NASA Astrophysics Data System (ADS)

Mues, Sarah; Lilge, Inga; Schönherr, Holger; Kemper, Björn; Schnekenburger, Jürgen

2017-02-01

The major problem of Digital Holographic Microscopy (DHM) long term live cell imaging is that over time most of the tracked cells move out of the image area and other ones move in. Therefore, most of the cells are lost for the evaluation of individual cellular processes. Here, we present an effective solution for this crucial problem of long-term microscopic live cell analysis. We have generated functionalized slides containing areas of 250 μm per 200 μm. These micropatterned biointerfaces consist of passivating polyaclrylamide brushes (PAAm). Inner areas are backfilled with octadecanthiol (ODT), which allows cell attachment. The fouling properties of these surfaces are highly controllable and therefore the defined areas designed for the size our microscopic image areas were effective in keeping all cells inside the rectangles over the selected imaging period.

Intensity calibration of a laser scanning confocal microscope based on concentrated dyes.

PubMed

Model, Michael A; Blank, James L

2006-10-01

To find water-soluble fluorescent dyes with absorption in various regions of the spectrum and investigate their utility as standards for laser scanning confocal microscopy. Several dyes were found to have characteristics required for fluorescence microscopy standards. The intensity of biological fluorescent specimens was measured against the emission of concentrated dyes. Results using different optics and different microscopes were compared. Slides based on concentrated dyes can be prepared in a highly reproducible manner and are stable under laser scanning. Normalized fluorescence of biological specimens remains consistent with different objective lenses and is tolerant to some mismatch in optical filters or imperfect pinhole alignment. Careful choice of scanning parameters is necessary to ensure linearity of intensity measurements. Concentrated dyes provide a robust and inexpensive intensity standard that can be used in basic research or clinical studies.

Utility of Digital Stereo Images for Optic Disc Evaluation

PubMed Central

Ying, Gui-shuang; Pearson, Denise J.; Bansal, Mayank; Puri, Manika; Miller, Eydie; Alexander, Judith; Piltz-Seymour, Jody; Nyberg, William; Maguire, Maureen G.; Eledath, Jayan; Sawhney, Harpreet

2010-01-01

Purpose. To assess the suitability of digital stereo images for optic disc evaluations in glaucoma. Methods. Stereo color optic disc images in both digital and 35-mm slide film formats were acquired contemporaneously from 29 subjects with various cup-to-disc ratios (range, 0.26–0.76; median, 0.475). Using a grading scale designed to assess image quality, the ease of visualizing optic disc features important for glaucoma diagnosis, and the comparative diameters of the optic disc cup, experienced observers separately compared the primary digital stereo images to each subject's 35-mm slides, to scanned images of the same 35-mm slides, and to grayscale conversions of the digital images. Statistical analysis accounted for multiple gradings and comparisons and also assessed image formats under monoscopic viewing. Results. Overall, the quality of primary digital color images was judged superior to that of 35-mm slides (P < 0.001), including improved stereo (P < 0.001), but the primary digital color images were mostly equivalent to the scanned digitized images of the same slides. Color seemingly added little to grayscale optic disc images, except that peripapillary atrophy was best seen in color (P < 0.0001); both the nerve fiber layer (P < 0.0001) and the paths of blood vessels on the optic disc (P < 0.0001) were best seen in grayscale. The preference for digital over film images was maintained under monoscopic viewing conditions. Conclusions. Digital stereo optic disc images are useful for evaluating the optic disc in glaucoma and allow the application of advanced image processing applications. Grayscale images, by providing luminance distinct from color, may be informative for assessing certain features. PMID:20505199

Mispair-specific Recruitment of the Mlh1-Pms1 Complex Identifies Repair Substrates of the Saccharomyces cerevisiae Msh2-Msh3 Complex*

PubMed Central

Srivatsan, Anjana; Bowen, Nikki; Kolodner, Richard D.

2014-01-01

DNA mismatch repair is initiated by either the Msh2-Msh6 or the Msh2-Msh3 mispair recognition heterodimer. Here we optimized the expression and purification of Saccharomyces cerevisiae Msh2-Msh3 and performed a comparative study of Msh2-Msh3 and Msh2-Msh6 for mispair binding, sliding clamp formation, and Mlh1-Pms1 recruitment. Msh2-Msh3 formed sliding clamps and recruited Mlh1-Pms1 on +1, +2, +3, and +4 insertion/deletions and CC, AA, and possibly GG mispairs, whereas Msh2-Msh6 formed mispair-dependent sliding clamps and recruited Mlh1-Pms1 on 7 of the 8 possible base:base mispairs, the +1 insertion/deletion mispair, and to a low level on the +2 but not the +3 or +4 insertion/deletion mispairs and not on the CC mispair. The mispair specificity of sliding clamp formation and Mlh1-Pms1 recruitment but not mispair binding alone correlated best with genetic data on the mispair specificity of Msh2-Msh3- and Msh2-Msh6-dependent mismatch repair in vivo. Analysis of an Msh2-Msh6/Msh3 chimeric protein and mutant Msh2-Msh3 complexes showed that the nucleotide binding domain and communicating regions but not the mispair binding domain of Msh2-Msh3 are responsible for the extremely rapid dissociation of Msh2-Msh3 sliding clamps from DNA relative to that seen for Msh2-Msh6, and that amino acid residues predicted to stabilize Msh2-Msh3 interactions with bent, strand-separated mispair-containing DNA are more critical for the recognition of small +1 insertion/deletions than larger +4 insertion/deletions. PMID:24550389

Mispair-specific recruitment of the Mlh1-Pms1 complex identifies repair substrates of the Saccharomyces cerevisiae Msh2-Msh3 complex.

PubMed

Srivatsan, Anjana; Bowen, Nikki; Kolodner, Richard D

2014-03-28

DNA mismatch repair is initiated by either the Msh2-Msh6 or the Msh2-Msh3 mispair recognition heterodimer. Here we optimized the expression and purification of Saccharomyces cerevisiae Msh2-Msh3 and performed a comparative study of Msh2-Msh3 and Msh2-Msh6 for mispair binding, sliding clamp formation, and Mlh1-Pms1 recruitment. Msh2-Msh3 formed sliding clamps and recruited Mlh1-Pms1 on +1, +2, +3, and +4 insertion/deletions and CC, AA, and possibly GG mispairs, whereas Msh2-Msh6 formed mispair-dependent sliding clamps and recruited Mlh1-Pms1 on 7 of the 8 possible base:base mispairs, the +1 insertion/deletion mispair, and to a low level on the +2 but not the +3 or +4 insertion/deletion mispairs and not on the CC mispair. The mispair specificity of sliding clamp formation and Mlh1-Pms1 recruitment but not mispair binding alone correlated best with genetic data on the mispair specificity of Msh2-Msh3- and Msh2-Msh6-dependent mismatch repair in vivo. Analysis of an Msh2-Msh6/Msh3 chimeric protein and mutant Msh2-Msh3 complexes showed that the nucleotide binding domain and communicating regions but not the mispair binding domain of Msh2-Msh3 are responsible for the extremely rapid dissociation of Msh2-Msh3 sliding clamps from DNA relative to that seen for Msh2-Msh6, and that amino acid residues predicted to stabilize Msh2-Msh3 interactions with bent, strand-separated mispair-containing DNA are more critical for the recognition of small +1 insertion/deletions than larger +4 insertion/deletions.

Grain Boundary Sliding in Deforming Wehrlite: Rheology and Microstructure

NASA Astrophysics Data System (ADS)

Zhao, N.; Hirth, G.; Cooper, R. F.; Kruckenberg, S. C.

2016-12-01

Elastic anisotropy of Earth's upper mantle used to be attributed exclusively to dislocation creep. However, recent experimental results suggest that crystallographic preferred orientation (CPO) in olivine, which contributes to elastic anisotropy, could also form during grain boundary sliding [e.g., 1-3]. Nevertheless, the fundamental problem of how CPO forms during grain boundary sliding is not fully understood. Our current efforts examine the grain-size-sensitive flow of wehrlite, to characterize the influence of the second phase (clinopyroxene) both on olivine CPO formation as well as the propensity of grain boundary sliding and accumulated strain to effect solid-state phase separation (i.e., metamorphic layering). Creep tests on fine-grain-size (2-5 µm) olivine and clinopyroxene aggregates (T =1100-1200ºC; P = 1.5 GPa; γ=3-7) have been conducted. These reveal strong type-B fabric for olivine. Characterization of effects of grain size, temperature and applied strain rate reveal the grain size dependence, stress exponent and activation energy of the flow kinetics of wehrlite. The stress exponent, which is similar to stress exponent for harzburgite reported by Sundberg & Cooper [1], and grain-size dependence suggest that the dominant deformation mechanism in our experiments may be grain boundary sliding. A large stress drop in early segments of experiments suggest an evolution of microstructure. The Fourier transform of backscatter images demonstrates that there exists a direction of foliation, defined by Ol-Cpx heterophase boundaries, which may be the key to understand the development of CPO formation. [1] Sundberg, M. & Cooper, R. F., J. Geophys. Res., 2008. [2] Miyazaki, T., Sueyoshi, K., and Hiraga, T., Nature, 2013. [3] Tielke, J. A., L. N. Hansen, M. Tasaka, C. Meyers, M. E. Zimmerman, and D. L. Kohlstedt, J. Geophys. Res., 2016.

Branching, Superdiffusion and Stress Relaxation in Surfactant Micelles

NASA Astrophysics Data System (ADS)

Sureshkumar, R.; Dhakal, S.; Syracuse University Team

2016-11-01

We investigate the mechanism of branch formation and its effects on the dynamics and rheology of a model cationic micellar fluid using molecular dynamics (MD) simulations. Branched structures are formed upon increasing counter ion density. A sharp decrease in the solution viscosity with increasing salinity has long been attributed to the sliding motion of micellar branches along the main chain. Simulations not only provide firm evidence of branch sliding in real time, but also show enhanced diffusion of surfactants by virtue of such motion. Insights into the mechanism of stress relaxation associated with branch sliding will be discussed. Specifically, an externally imposed stress damps out more quickly in a branched system compared to that in an unbranched one. NSF Grants 1049489, 1049454.

The Fibrin slide assay for detecting urokinase activity in human fetal kidney cells

NASA Technical Reports Server (NTRS)

Sedor, K.

1985-01-01

The Fibrin Slide Technique of Hau C. Kwaan and Tage Astrup is discussed. This relatively simple assay involves two steps: the formation of an artificial clot and then the addition of an enzyme (UKOKINASE) to dissolve the clot. The actual dissolving away of the clot is detected by the appearance of holes (lysis zones) in the stained clot. The procedure of Kwaan and Astrup is repeated, along with modifications and suggestions for improvements based on experience with the technique.

Landslide assessment of Newell Creek Canyon, Oregon City, Oregon

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

Growney, L.; Burris, L.; Garletts, D.

1993-04-01

A study has been conducted in Newell Creek Canyon near Oregon City, Oregon, T3S, T2S, R2E. A landslide inventory has located 53 landslides in the 2.8 km[sup 2] area. The landslides range in area from approximately 15,000m[sup 2] to 10m[sup 2]. Past slides cover an approximate 7% of the canyon area. Landslide processes include: slump, slump-translational, slump-earthflow and earthflow. Hard, impermeable clay-rich layers in the Troutdale Formation form the failure planes for most of the slides. Slopes composed of Troutdale material may seem to be stable, but when cuts and fills are produced, slope failure is common because of themore » perched water tables and impermeable failure planes. Good examples of cut and fill failures are present on Highway 213 which passes through Newell Creek Canyon. Almost every cut and fill has failed since the road construction began. The latest failure is in the fill located at mile-post 2.1. From data gathered, a slope stability risk map was generated. Stability risk ratings are divided into three groups: high, moderate and low. High risk of slope instability is designated to all landslides mapped in the slide inventory. Moderate risk is designated to slopes in the Troutdale Formation greater than 8[degree]. Low risk is designated to slopes in the Troutdale Formation less than 8[degree].« less

Estrogenic activity of tamoxifen on normal mammary parenchyma in the luteal phase of the menstrual cycle.

PubMed

Facina, G; de Lima, G R; Simões, M J; Novo, N F; Gebrim, L H

1997-01-01

Tamoxifen, an anti-estrogenic drug used in the adjuvant treatment of breast cancer, deserves more investigation for the determination of its efficacy as a prophylactic agent against breast cancer in high risk women. Thus, the action of tamoxifen on the human mammary gland was studied by measuring the number of lysosomes in normal mammary epithelium during the administration of tamoxifen. Tamoxifen was administered only during the luteal phase of the menstrual cycle to avoid interference with corpus luteum formation. A fragment of breast tissue adjacent to a fibroadenoma was obtained during surgery from 35 premenopausal women aged 15 to 37 years who had been eumenorrheic for at least 6 months; 18 of these patients were treated with tamoxifen and 17 were used as controls. Lysosome counts were performed under the light microscope on slides submitted to the acid phosphatase cytochemical technique and the data were analyzed statistically by the Mann-Whitney test. The fragments from the group treated with tamoxifen showed a significant decrease in lysosome numbers. Tamoxifen administered after ovulation significantly decreases the number of lysosomes in the cells of normal mammary epithelium, demonstrating the antiestrogenic effect of the drug on this target tissue.

A follow-up on the analytical study of discolouration of the marble statues of Orsanmichele in Florence.

PubMed

Pinna, Daniela; Galeotti, Monica; Rizzo, Adriana; Cantisani, Emma; Sciutto, Giorgia; Zangheri, Martina; Prati, Silvia; Mazzeo, Rocco; Roda, Aldo

2017-01-01

The research complements the complex study carried out to understand the source of brown discolourations of ten marble statues in the Church of Orsanmichele in Florence, Italy. Originally located in exterior niches, the statues were restored to reverse the extensive alterations they had undergone throughout the centuries. One of the major alterations was the application of a dark brown patina that dated just after 1789. After the statues were placed indoors, brownish discolourations started to appear on their surfaces. Cross sections were examined using FTIR mapping and immunological methods. In parallel, the pyrolysis-gas chromatography/mass spectrometry (py-GC/MS) data already obtained from the statues' scrapings were compared with data from aged casein films applied to microscope glass slides and aged milk-treated marble. All the statues had been treated with milk-based substances before the time the bronze patina was applied. The values of temperature and illumination of the room were important factors in the ageing of organic substances and in the formation of calcium oxalates. It is likely that products of thermo-oxidation and photo-oxidation of the oils together with the oxalates caused the darkening. The marble samples corresponded to a Lunense provenance.

An adaptive extended finite element method for the analysis of agglomeration of colloidal particles in a flowing fluid

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

Choi, Young Joon; Jorshari, Razzi Movassaghi; Djilali, Ned

2015-03-10

Direct numerical simulations of the flow-nanoparticle interaction in a colloidal suspension are presented using an extended finite element method (XFEM) in which the dynamics of the nanoparticles is solved in a fully-coupled manner with the flow. The method is capable of accurately describing solid-fluid interfaces without the need of boundary-fitted meshes to investigate the dynamics of particles in complex flows. In order to accurately compute the high interparticle shear stresses and pressures while minimizing computing costs, an adaptive meshing technique is incorporated with the fluid-structure interaction algorithm. The particle-particle interaction at the microscopic level is modeled using the Lennard-Jones (LJ)more » potential and the corresponding potential parameters are determined by a scaling procedure. The study is relevant to the preparation of inks used in the fabrication of catalyst layers for fuel cells. In this paper, we are particularly interested in investigating agglomeration of the nanoparticles under external shear flow in a sliding bi-periodic Lees-Edwards frame. The results indicate that the external shear has a crucial impact on the structure formation of colloidal particles in a suspension.« less

Living Cell Microarrays: An Overview of Concepts

PubMed Central

Jonczyk, Rebecca; Kurth, Tracy; Lavrentieva, Antonina; Walter, Johanna-Gabriela; Scheper, Thomas; Stahl, Frank

2016-01-01

Living cell microarrays are a highly efficient cellular screening system. Due to the low number of cells required per spot, cell microarrays enable the use of primary and stem cells and provide resolution close to the single-cell level. Apart from a variety of conventional static designs, microfluidic microarray systems have also been established. An alternative format is a microarray consisting of three-dimensional cell constructs ranging from cell spheroids to cells encapsulated in hydrogel. These systems provide an in vivo-like microenvironment and are preferably used for the investigation of cellular physiology, cytotoxicity, and drug screening. Thus, many different high-tech microarray platforms are currently available. Disadvantages of many systems include their high cost, the requirement of specialized equipment for their manufacture, and the poor comparability of results between different platforms. In this article, we provide an overview of static, microfluidic, and 3D cell microarrays. In addition, we describe a simple method for the printing of living cell microarrays on modified microscope glass slides using standard DNA microarray equipment available in most laboratories. Applications in research and diagnostics are discussed, e.g., the selective and sensitive detection of biomarkers. Finally, we highlight current limitations and the future prospects of living cell microarrays. PMID:27600077

Jan Evangelista Purkyně (1787-1869) and his instruments for microscopic research in the field of neuroscience.

PubMed

Chvátal, Alexandr

2017-01-01

The findings obtained by the famous nineteenth-century Czech scientist Jan Evangelista Purkyně (1787-1869) in the field of microscopic structure of animal and human tissues, including the brain, spinal cord, and nerves, have already been described in depth in a number of older and newer publications. The present article contains an overview of the instruments and tools that Purkyně and his assistants used for microscopic research of tissue histology. Some of these instruments were developed either by Purkyně alone, such as the microtomic compressor, or together with his assistant Adolph Oschatz, such as the microtome. A brief overview of the development of the cutting engines suggests that the first microtome, a prototype of modern sliding microtomes, was designed and constructed under the supervision of Purkyně at the Institute of Physiology in Wrocław. Purkyně and his assistants, thus, not only obtained important findings of animal and human nervous and other tissues but also substantially contributed to the development of instruments and tools for their study, a fact often forgotten today.

Upright Imaging of Drosophila Egg Chambers

PubMed Central

Manning, Lathiena; Starz-Gaiano, Michelle

2015-01-01

Drosophila melanogaster oogenesis provides an ideal context for studying varied developmental processes since the ovary is relatively simple in architecture, is well-characterized, and is amenable to genetic analysis. Each egg chamber consists of germ-line cells surrounded by a single epithelial layer of somatic follicle cells. Subsets of follicle cells undergo differentiation during specific stages to become several different cell types. Standard techniques primarily allow for a lateral view of egg chambers, and therefore a limited view of follicle cell organization and identity. The upright imaging protocol describes a mounting technique that enables a novel, vertical view of egg chambers with a standard confocal microscope. Samples are first mounted between two layers of glycerin jelly in a lateral (horizontal) position on a glass microscope slide. The jelly with encased egg chambers is then cut into blocks, transferred to a coverslip, and flipped to position egg chambers upright. Mounted egg chambers can be imaged on either an upright or an inverted confocal microscope. This technique enables the study of follicle cell specification, organization, molecular markers, and egg development with new detail and from a new perspective. PMID:25867882

Perivascular epithelioid cell neoplasm of the urinary bladder in an adolescent: a case report and review of the literature

PubMed Central

2012-01-01

Abstract Perivascular epithelioid cell neoplasms (PEComas) of the urinary bladder are extremely rare and the published cases were comprised predominantly of middle-aged patients. Herein, the authors present the first urinary bladder PEComa occurring in an adolescent. This 16-year-old Chinese girl present with a 3-year history of abdominal discomfort and a solid mass was documented in the urinary bladder by ultrasonography. Two years later, at the age of 18, the patient underwent transurethral resection of the bladder tumor. Microscopically, the tumor was composed of spindled cells mixed with epithelioid cells. Immunohistochemically, the tumor were strongly positive for HMB45, smooth muscle actin, muscle-specific actin, and H-caldesmon. Fluorescence in situ hybridization analysis revealed no evidence of EWSR1 gene rearrangement. The patient had been in a good status without evidence of recurrence 13 months after surgery. Urinary bladder PEComa is an extremely rare neoplasm and seems occur predominantly in middle-aged patients. However, this peculiar lesion can develop in pediatric population and therefore it should be rigorously distinguished from their mimickers. Virtual slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1870004378817301 PMID:23276164

Dry Sliding Wear Behavior and Subsurface Microstructure Evolution of Mg97Zn1Y2 Alloy in a Wide Sliding Speed Range

NASA Astrophysics Data System (ADS)

An, J.; Xuan, X. H.; Zhao, J.; Sun, W.; Liang, C.

2016-12-01

The wear properties of Mg97Zn1Y2 alloy were investigated using the pin-on-disk wear machine within a load range of 20-380 N and a sliding speed range of 0.2-4.0 m/s. Analysis of worn surfaces using scanning electron microscope and energy-dispersive x-ray spectrometer revealed that wear mechanisms including abrasion + oxidation, delamination accompanied by heavy surface oxidation and delamination operated in mild wear regime, while wear mechanisms such as severe plastic deformation, severe plastic deformation accompanied by spallation of oxidation layer and surface melting prevailed in severe wear regime. The microstructural evolution and hardness change in subsurfaces were examined by optical microscopy and hardness tester. The transformation of surface material from the deformed into dynamic recrystallization (DRX) microstructure was observed before and after mild-to-severe transition. The reason for mild-to-severe wear transition was identified as the transformation of strain hardening to DRX softening in subsurface. Mg97Zn1Y2 alloy has a superior mild-to-severe wear transition resistance to AZ alloys because of its higher recrystallization temperature. A novel model for evaluating the critical surface temperature of mild-to-severe wear transition was established using DRX kinetics.

Time-lapse nanoscopy of friction in the non-Amontons and non-Coulomb regime.

PubMed

Ishida, Tadashi; Sato, Takaaki; Ishikawa, Takahiro; Oguma, Masatsugu; Itamura, Noriaki; Goda, Keisuke; Sasaki, Naruo; Fujita, Hiroyuki

2015-03-11

Originally discovered by Leonard da Vinci in the 15th century, the force of friction is directly proportional to the applied load (known as Amontons' first law of friction). Furthermore, kinetic friction is independent of the sliding speed (known as Coulomb's law of friction). These empirical laws break down at high normal pressure (due to plastic deformation) and low sliding speed (in the transition regime between static friction and kinetic friction). An important example of this phenomenon is friction between the asperities of tectonic plates on the Earth. Despite its significance, little is known about the detailed mechanism of friction in this regime due to the lack of experimental methods. Here we demonstrate in situ time-lapse nanoscopy of friction between asperities sliding at ultralow speed (∼0.01 nm/s) under high normal pressure (∼GPa). This is made possible by compressing and rubbing a pair of nanometer-scale crystalline silicon anvils with electrostatic microactuators and monitoring its dynamical evolution with a transmission electron microscope. Our analysis of the time-lapse movie indicates that superplastic behavior is induced by decrystallization, plastic deformation, and atomic diffusion at the asperity-asperity interface. The results hold great promise for a better understanding of quasi-static friction under high pressure for geoscience, materials science, and nanotechnology.

Direct-current triboelectricity generation by a sliding Schottky nanocontact on MoS2 multilayers

NASA Astrophysics Data System (ADS)

Liu, Jun; Goswami, Ankur; Jiang, Keren; Khan, Faheem; Kim, Seokbeom; McGee, Ryan; Li, Zhi; Hu, Zhiyu; Lee, Jungchul; Thundat, Thomas

2018-02-01

The direct conversion of mechanical energy into electricity by nanomaterial-based devices offers potential for green energy harvesting1-3. A conventional triboelectric nanogenerator converts frictional energy into electricity by producing alternating current (a.c.) triboelectricity. However, this approach is limited by low current density and the need for rectification2. Here, we show that continuous direct-current (d.c.) with a maximum density of 106 A m-2 can be directly generated by a sliding Schottky nanocontact without the application of an external voltage. We demonstrate this by sliding a conductive-atomic force microscope tip on a thin film of molybdenum disulfide (MoS2). Finite element simulation reveals that the anomalously high current density can be attributed to the non-equilibrium carrier transport phenomenon enhanced by the strong local electrical field (105-106 V m-2) at the conductive nanoscale tip4. We hypothesize that the charge transport may be induced by electronic excitation under friction, and the nanoscale current-voltage spectra analysis indicates that the rectifying Schottky barrier at the tip-sample interface plays a critical role in efficient d.c. energy harvesting. This concept is scalable when combined with microfabricated or contact surface modified electrodes, which makes it promising for efficient d.c. triboelectricity generation.

Observation Platform for Dynamic Biomedical and Biotechnology Experiments Using the International Space Station (ISS) Light Microscopy Module (LMM)

NASA Technical Reports Server (NTRS)

Kurk, Michael A. (Andy)

2015-01-01

Techshot, Inc., has developed an observation platform for the LMM on the ISS that will enable biomedical and biotechnology experiments. The LMM Dynamic Stage consists of an electronics module and the first two of a planned suite of experiment modules. Specimens and reagent solutions can be injected into a small, hollow microscope slide-the heart of the innovation-via a combination of small reservoirs, pumps, and valves. A life science experiment module allows investigators to load up to two different fluids for on-orbit, real-time image cytometry. Fluids can be changed to initiate a process, fix biological samples, or retrieve suspended cells. A colloid science experiment module conducts microparticle and nanoparticle tests for investigation of colloid self-assembly phenomena. This module includes a hollow glass slide and heating elements for the creation of a thermal gradient from one end of the slide to the other. The electronics module supports both experiment modules and contains a unique illuminator/condenser for bright and dark field and phase contrast illumination, power supplies for two piezoelectric pumps, and controller boards for pumps and valves. This observation platform safely contains internal fluids and will greatly accelerate the research and development (R&D) cycle of numerous experiments, products, and services aboard the ISS.

Sperm Hy-Liter™: an effective tool for the detection of spermatozoa in sexual assault exhibits.

PubMed

De Moors, Anick; Georgalis, Tina; Armstrong, Gail; Modler, Jeff; Frégeau, Chantal J

2013-05-01

A fluorescence-based assay specifically targeting human spermatozoa was tested and optimized for best staining results using a variety of mock sexual assault samples. Swab clippings versus whole swabs were evaluated for best sample preparation and to simplify workflow (direct application versus swab extraction). The practicality and sensitivity of Sperm Hy-Liter™ was compared to our current phase contrast microscopy protocol for searching for the presence of spermatozoa. Sperm Hy-Liter™ was more sensitive than phase contrast microscopy and was able to detect spermatozoa more effectively in actual sexual assault samples (recent [N=240] or 24 years old [N=4]) containing few spermatozoa. Correlations were drawn between the Sperm Hy-Liter™ spermatozoa counts and the AmpFlSTR(®) Profiler(®) Plus male profiles generated from the sperm cell DNA fractions of semen containing swabs and swab clippings. In addition, recovered spermatozoa from Sperm Hy-Liter™-stained slides with greater than 40 spermatozoa produced full STR male profiles in 20.3% of slides tested and partial STR male profiles in 52.8% of slides tested. The adoption of Sperm Hy-Liter™ offers a means to standardize and improve the efficiency of the microscopic screening of sexual assault evidence. Crown Copyright © 2013. Published by Elsevier Ireland Ltd. All rights reserved.

High resolution FTIR imaging provides automated discrimination and detection of single malaria parasite infected erythrocytes on glass.

PubMed

Perez-Guaita, David; Andrew, Dean; Heraud, Philip; Beeson, James; Anderson, David; Richards, Jack; Wood, Bayden R

2016-06-23

New highly sensitive tools for malaria diagnostics are urgently needed to enable the detection of infection in asymptomatic carriers and patients with low parasitemia. In pursuit of a highly sensitive diagnostic tool that can identify parasite infections at the single cell level, we have been exploring Fourier transform infrared (FTIR) microscopy using a Focal Plane Array (FPA) imaging detector. Here we report for the first time the application of a new optic configuration developed by Agilent that incorporates 25× condenser and objective Cassegrain optics with a high numerical aperture (NA = 0.81) along with additional high magnification optics within the microscope to provide 0.66 micron pixel resolution (total IR system magnification of 61×) to diagnose malaria parasites at the single cell level on a conventional glass microscope slide. The high quality images clearly resolve the parasite's digestive vacuole demonstrating sub-cellular resolution using this approach. Moreover, we have developed an algorithm that first detects the cells in the infrared image, and secondly extracts the average spectrum. The average spectrum is then run through a model based on Partial Least Squares-Discriminant Analysis (PLS-DA), which diagnoses unequivocally the infected from normal cells. The high quality images, and the fact this measurement can be achieved without a synchrotron source on a conventional glass slide, shows promise as a potential gold standard for malaria detection at the single cell level.

Impact of virtual microscopy with conventional microscopy on student learning in dental histology.

PubMed

Hande, Alka Harish; Lohe, Vidya K; Chaudhary, Minal S; Gawande, Madhuri N; Patil, Swati K; Zade, Prajakta R

2017-01-01

In dental histology, the assimilation of histological features of different dental hard and soft tissues is done by conventional microscopy. This traditional method of learning prevents the students from screening the entire slide and change of magnification. To address these drawbacks, modification in conventional microscopy has evolved and become motivation for changing the learning tool. Virtual microscopy is the technique in which there is complete digitization of the microscopic glass slide, which can be analyzed on a computer. This research is designed to evaluate the effectiveness of virtual microscopy with conventional microscopy on student learning in dental histology. A cohort of 105 students were included and randomized into three groups: A, B, and C. Group A students studied the microscopic features of oral histologic lesions by conventional microscopy, Group B by virtual microscopy, and Group C by both conventional and virtual microscopy. The students' understanding of the subject was evaluated by a prepared questionnaire. The effectiveness of the study designs on knowledge gains and satisfaction levels was assessed by statistical assessment of differences in mean test scores. The difference in score between Groups A, B, and C at pre- and post-test was highly significant. This enhanced understanding of the subject may be due to benefits of using virtual microscopy in teaching histology. The augmentation of conventional microscopy with virtual microscopy shows enhancement of the understanding of the subject as compared to the use of conventional microscopy and virtual microscopy alone.

Early development of fern gametophytes in microgravity

NASA Technical Reports Server (NTRS)

Roux, Stanley J.; Chatterjee, Ani; Hillier, Sheila; Cannon, Tom

2003-01-01

Dormant spores of the fern Ceratopteris richardii were flown on Shuttle mission STS-93 to evaluate the effects of micro-g on their development and on their pattern of gene expression. Prior to flight the spores were sterilized and sown into one of two environments: (1) Microscope slides in a video-microscopy module; and (2) Petri dishes. All spores were then stored in darkness until use. Spore germination was initiated on orbit after exposure to light. For the spores on microscope slides, cell level changes were recorded through the clear spore coat of the spores by video microscopy. After their exposure to light, spores in petri dishes were frozen in orbit at four different time points during which on earth gravity fixes the polarity of their development. Spores were then stored frozen in Biological Research in Canister units until recovery on earth. The RNAs from these cells and from 1-g control cells were extracted and analyzed on earth after flight to assay changes in gene expression. Video microscopy results revealed that the germinated spores developed normally in microgravity, although the polarity of their development, which is guided by gravity on earth, was random in space. Differential Display-PCR analyses of RNA extracted from space-flown cells showed that there was about a 5% change in the pattern of gene expression between cells developing in micro-g compared to those developing on earth. c2002 Published by Elsevier Science Ltd on behalf of COSPAR.

Standardisation of DNA quantitation by image analysis: quality control of instrumentation.

PubMed

Puech, M; Giroud, F

1999-05-01

DNA image analysis is frequently performed in clinical practice as a prognostic tool and to improve diagnosis. The precision of prognosis and diagnosis depends on the accuracy of analysis and particularly on the quality of image analysis systems. It has been reported that image analysis systems used for DNA quantification differ widely in their characteristics (Thunissen et al.: Cytometry 27: 21-25, 1997). This induces inter-laboratory variations when the same sample is analysed in different laboratories. In microscopic image analysis, the principal instrumentation errors arise from the optical and electronic parts of systems. They bring about problems of instability, non-linearity, and shading and glare phenomena. The aim of this study is to establish tools and standardised quality control procedures for microscopic image analysis systems. Specific reference standard slides have been developed to control instability, non-linearity, shading and glare phenomena and segmentation efficiency. Some systems have been controlled with these tools and these quality control procedures. Interpretation criteria and accuracy limits of these quality control procedures are proposed according to the conclusions of a European project called PRESS project (Prototype Reference Standard Slide). Beyond these limits, tested image analysis systems are not qualified to realise precise DNA analysis. The different procedures presented in this work determine if an image analysis system is qualified to deliver sufficiently precise DNA measurements for cancer case analysis. If the controlled systems are beyond the defined limits, some recommendations are given to find a solution to the problem.

Movement triggers and remediation in a fracture-dominated translational landslide at the Oregon coast

USGS Publications Warehouse

Priest, George R.; Allan, Jonathan; Niem, Alan; Niem, Wendy A.; Dickenson, Stephen E.

2009-01-01

The Johnson Creek landslide is a translational slide in seaward dipping Miocene siltstone and sandstone (Astoria Formation) and an overlying Quaternary marine terrace deposit. The slide terminates in a sea cliff and has a hummocky to nearly horizontal ground surface. The basal slide plane, however, slopes subparallel to the dip of the Miocene rocks, except beneath the back-tilted toe blocks where it curves upward. The siltstone and sandstone have low estimated permeability but cores and field mapping reveal an extensive fracture system within the slide mass. The slide mainly moves in response to groundwater pressure and coastal erosion of the toe. Limit-equilibrium stability analyses indicate that 3 m of erosion at the toe would destabilize the slide for most of the wet season, although no movement could be directly attributed to erosion in the 5 years of observation. Intense rainfall events raise pore-water pressure throughout the slide in the form of pulses of water pressure traveling from the headwall graben down the axis of the slide at rates of 1.4-2.5 m/hr in the upper part, and 3.5 m/hr to virtually instantaneous in the middle part. Infiltration of meteoric water was only ~50 mm/hr. Slope of the water table exceeds topographic slope from the head to the toe of the slide, so infiltration was too slow to directly raise head in 90 percent of the slide mass where the saturated zone is deeper than a few meters. Only at the headwall graben was the saturated zone shallow enough for rainfall events to trigger pulses of water pressure through the entire saturated zone. When a pressure pulse reached the threshold pressure for movement in the central part of the slide, the whole slide began slow, creeping movement. As head became larger and larger than the threshold for movement in more of the slide mass, movement accelerated and differential displacement between internal slide blocks became more pronounced. These findings suggest that dewatering the shallowest part of the saturated zone in this type of slide will stop these rapid pressure pulses, thereby stopping or greatly reducing seasonal movement. If slides are also subject to continual removal of material from the toe, especially where there are back-tilted toe blocks, then some type of buttress or tied-back shear pile wall may be the only effective long term remediation.

Large scale infrared imaging of tissue micro arrays (TMAs) using a tunable Quantum Cascade Laser (QCL) based microscope.

PubMed

Bassan, Paul; Weida, Miles J; Rowlette, Jeremy; Gardner, Peter

2014-08-21

Chemical imaging in the field of vibrational spectroscopy is developing into a promising tool to complement digital histopathology. Applications include screening of biopsy tissue via automated recognition of tissue/cell type and disease state based on the chemical information from the spectrum. For integration into clinical practice, data acquisition needs to be speeded up to implement a rack based system where specimens are rapidly imaged to compete with current visible scanners where 100's of slides can be scanned overnight. Current Fourier transform infrared (FTIR) imaging with focal plane array (FPA) detectors are currently the state-of-the-art instrumentation for infrared absorption chemical imaging, however recent development in broadly tunable lasers in the mid-IR range is considered the most promising potential candidate for next generation microscopes. In this paper we test a prototype quantum cascade laser (QCL) based spectral imaging microscope with a focus on discrete frequency chemical imaging. We demonstrate how a protein chemical image of the amide I band (1655 cm(-1)) of a 2 × 2.4 cm(2) breast tissue microarray (TMA) containing over 200 cores can be measured in 9 min. This result indicates that applications requiring chemical images from a few key wavelengths would be ideally served by laser-based microscopes.

Plasma cell quantification in bone marrow by computer-assisted image analysis.

PubMed

Went, P; Mayer, S; Oberholzer, M; Dirnhofer, S

2006-09-01

Minor and major criteria for the diagnosis of multiple meloma according to the definition of the WHO classification include different categories of the bone marrow plasma cell count: a shift from the 10-30% group to the > 30% group equals a shift from a minor to a major criterium, while the < 10% group does not contribute to the diagnosis. Plasma cell fraction in the bone marrow is therefore critical for the classification and optimal clinical management of patients with plasma cell dyscrasias. The aim of this study was (i) to establish a digital image analysis system able to quantify bone marrow plasma cells and (ii) to evaluate two quantification techniques in bone marrow trephines i.e. computer-assisted digital image analysis and conventional light-microscopic evaluation. The results were compared regarding inter-observer variation of the obtained results. Eighty-seven patients, 28 with multiple myeloma, 29 with monoclonal gammopathy of undetermined significance, and 30 with reactive plasmocytosis were included in the study. Plasma cells in H&E- and CD138-stained slides were quantified by two investigators using light-microscopic estimation and computer-assisted digital analysis. The sets of results were correlated with rank correlation coefficients. Patients were categorized according to WHO criteria addressing the plasma cell content of the bone marrow (group 1: 0-10%, group 2: 11-30%, group 3: > 30%), and the results compared by kappa statistics. The degree of agreement in CD138-stained slides was higher for results obtained using the computer-assisted image analysis system compared to light microscopic evaluation (corr.coeff. = 0.782), as was seen in the intra- (corr.coeff. = 0.960) and inter-individual results correlations (corr.coeff. = 0.899). Inter-observer agreement for categorized results (SM/PW: kappa 0.833) was in a high range. Computer-assisted image analysis demonstrated a higher reproducibility of bone marrow plasma cell quantification. This might be of critical importance for diagnosis, clinical management and prognostics when plasma cell numbers are low, which makes exact quantifications difficult.

RandomSpot: A web-based tool for systematic random sampling of virtual slides.

PubMed

Wright, Alexander I; Grabsch, Heike I; Treanor, Darren E

2015-01-01

This paper describes work presented at the Nordic Symposium on Digital Pathology 2014, Linköping, Sweden. Systematic random sampling (SRS) is a stereological tool, which provides a framework to quickly build an accurate estimation of the distribution of objects or classes within an image, whilst minimizing the number of observations required. RandomSpot is a web-based tool for SRS in stereology, which systematically places equidistant points within a given region of interest on a virtual slide. Each point can then be visually inspected by a pathologist in order to generate an unbiased sample of the distribution of classes within the tissue. Further measurements can then be derived from the distribution, such as the ratio of tumor to stroma. RandomSpot replicates the fundamental principle of traditional light microscope grid-shaped graticules, with the added benefits associated with virtual slides, such as facilitated collaboration and automated navigation between points. Once the sample points have been added to the region(s) of interest, users can download the annotations and view them locally using their virtual slide viewing software. Since its introduction, RandomSpot has been used extensively for international collaborative projects, clinical trials and independent research projects. So far, the system has been used to generate over 21,000 sample sets, and has been used to generate data for use in multiple publications, identifying significant new prognostic markers in colorectal, upper gastro-intestinal and breast cancer. Data generated using RandomSpot also has significant value for training image analysis algorithms using sample point coordinates and pathologist classifications.

Effects of Material Combinations on Friction and Wear of PEEK/Steel Pairs under Oil-Lubricated Sliding Contacts

NASA Astrophysics Data System (ADS)

Akagaki, T.; Nakamura, T.; Hashimoto, Y.; Kawabata, M.

2017-05-01

The effects of material combinations on the friction and wear of PEEK/steel pairs are studied using blocks on a ring wear tester under oil-lubricated conditions. The rings are made of forged steel (SF540A) and a PEEK composite filled with 30 wt% carbon fibre. The surface roughness is 0.15 and 0.32 μm Ra, respectively. The blocks are also made of the same materials as the rings: the forged steel and the PEEK composite. Finished with an emery paper of #600, the surface roughness is 0.06 and 0.23 μm Ra, respectively. Sliding tests for 4 combinations of two materials are conducted. The load is increased up to 1177 N at 1 N s-1. The sliding velocity is varied in the range of 10 to 19 m s-1. In some cases, the ring temperature is measured with a thermocouple with a diameter of 0.5 mm, located 1 mm below the frictional surface. Results indicate that the forged steel’s ring and the PEEK composite’s block is the best combination among 4 combinations, because seizure does not occur under the increasing load up to 1177 N at the sliding velocity of 10-19 m s-1. In contrast, seizure occurs at 15 and 19 m s-1 in the other three combinations. However, the PEEK composite’s ring shows a lower friction coefficient as compared to the forged steel’s ring, when seizure does not occur. Wear scars are observed with a scanning electron microscope (SEM). The seizure mechanisms are then discussed.

Towards machine learned quality control: A benchmark for sharpness quantification in digital pathology.

PubMed

Campanella, Gabriele; Rajanna, Arjun R; Corsale, Lorraine; Schüffler, Peter J; Yagi, Yukako; Fuchs, Thomas J

2018-04-01

Pathology is on the verge of a profound change from an analog and qualitative to a digital and quantitative discipline. This change is mostly driven by the high-throughput scanning of microscope slides in modern pathology departments, reaching tens of thousands of digital slides per month. The resulting vast digital archives form the basis of clinical use in digital pathology and allow large scale machine learning in computational pathology. One of the most crucial bottlenecks of high-throughput scanning is quality control (QC). Currently, digital slides are screened manually to detected out-of-focus regions, to compensate for the limitations of scanner software. We present a solution to this problem by introducing a benchmark dataset for blur detection, an in-depth comparison of state-of-the art sharpness descriptors and their prediction performance within a random forest framework. Furthermore, we show that convolution neural networks, like residual networks, can be used to train blur detectors from scratch. We thoroughly evaluate the accuracy of feature based and deep learning based approaches for sharpness classification (99.74% accuracy) and regression (MSE 0.004) and additionally compare them to domain experts in a comprehensive human perception study. Our pipeline outputs spacial heatmaps enabling to quantify and localize blurred areas on a slide. Finally, we tested the proposed framework in the clinical setting and demonstrate superior performance over the state-of-the-art QC pipeline comprising commercial software and human expert inspection by reducing the error rate from 17% to 4.7%. Copyright © 2017. Published by Elsevier Ltd.

Testicular cytological profiles of apparently healthy male dromedary camels during rutting and non-rutting periods.

PubMed

Melaku, Simenew Keskes; Regassa, Fekadu; Tessema, Tesfaye Sisay; Kassa, Tesfu; Vencato, Juri; Owiny, David Okello; Stelletta, Calogero

2015-12-01

The aim of this study was to evaluate testicular cytological profiles of apparently healthy dromedary bulls during rutting and non-rutting periods. Pairs of testes from 26 (18 non-rutting and 8 rutting seasons) dromedary bulls 6-12 years old that were slaughtered at Akaki, Addis Ababa abattoir were sampled. A 21 gauge needle attached to 20mL syringe was used to collect Testicular Fine Needle Aspiration (TFNA) samples and five aspiration smears were prepared from each testis. A total of 312 slides (260 Testicular fine Needle Aspiration and 52 imprints) were examined. The mod ified May-Grunwald Giemsa (mMGG) technique and a light microscope were used to assess cellularity, morphology and quantification of the testicular. Sertoli and spermatogenic cells were identified and counted. The spermatic index (SI), Sertoli cell index (SEI) and the relationship between SI and SEI indexes (SSEI) were used to assess the ratio between mature spermatozoa and nursing cells. There were differences (P<0.05) between the rutting and non-rutting seasons among the spermatogenic and Sertoli cells. There were no differences between groups for primary spermatocyte numbers, early spermatid numbers and SSEI. There was no differences (P>0.05) between TFNA and imprint smear slides of the testicular cells except for Sertoli cell count and SEI. Filarial worm larvae were present on the TFNA smear slides of four animals. Imprint and TFNA smear slides had comparable cytological profiles in dromedary bulls and significant differences were observed between rutting and non-rutting periods. Copyright © 2015 Elsevier B.V. All rights reserved.

Micro axial tomography: A miniaturized, versatile stage device to overcome resolution anisotropy in fluorescence light microscopy

NASA Astrophysics Data System (ADS)

Staier, Florian; Eipel, Heinz; Matula, Petr; Evsikov, Alexei V.; Kozubek, Michal; Cremer, Christoph; Hausmann, Michael

2011-09-01

With the development of novel fluorescence techniques, high resolution light microscopy has become a challenging technique for investigations of the three-dimensional (3D) micro-cosmos in cells and sub-cellular components. So far, all fluorescence microscopes applied for 3D imaging in biosciences show a spatially anisotropic point spread function resulting in an anisotropic optical resolution or point localization precision. To overcome this shortcoming, micro axial tomography was suggested which allows object tilting on the microscopic stage and leads to an improvement in localization precision and spatial resolution. Here, we present a miniaturized device which can be implemented in a motor driven microscope stage. The footprint of this device corresponds to a standard microscope slide. A special glass fiber can manually be adjusted in the object space of the microscope lens. A stepwise fiber rotation can be controlled by a miniaturized stepping motor incorporated into the device. By means of a special mounting device, test particles were fixed onto glass fibers, optically localized with high precision, and automatically rotated to obtain views from different perspective angles under which distances of corresponding pairs of objects were determined. From these angle dependent distance values, the real 3D distance was calculated with a precision in the ten nanometer range (corresponding here to an optical resolution of 10-30 nm) using standard microscopic equipment. As a proof of concept, the spindle apparatus of a mature mouse oocyte was imaged during metaphase II meiotic arrest under different perspectives. Only very few images registered under different rotation angles are sufficient for full 3D reconstruction. The results indicate the principal advantage of the micro axial tomography approach for many microscopic setups therein and also those of improved resolutions as obtained by high precision localization determination.

Stress relaxation at a gelatin hydrogel-glass interface in direct shear sliding

NASA Astrophysics Data System (ADS)

Gupta, Vinit; Singh, Arun K.

2018-01-01

In this paper, we study experimentally the stress relaxation behavior of soft solids such as gelatin hydrogels on a smooth glass surface in direct shear sliding. It is observed experimentally that irrespective of pulling velocity, the sliding block relaxes to the same level of nonzero residual stress. However, residual stress increases with increasing gelatin concentration in the hydrogels. We have also validated a friction model for strong bond formation during steady relaxation in light of the experimental observations. Our theoretical analysis establishes that population of dangling chains at the sliding interface significantly affects the relaxation process. As a result, residual stress increases with increasing gelatin concentration or decreasing mesh size of the three-dimensional structures in the hydrogels. It is also found that the transition time, at which a weak bond converts to strong bond, increases with increasing mesh size of the hydrogels. Moreover, relaxation time constant of a strong bond decreases with increasing mesh size. However, activation length of a strong bond increases with mesh size. Finally, this study signifies the role of residual strength in frictional shear sliding and it is believed that these results should be useful to understand the role of residual stress in stick-slip instability.

The Starvation Resistance and Biofilm Formation of Enterococcus faecalis in Coexistence with Candida albicans, Streptococcus gordonii, Actinomyces viscosus, or Lactobacillus acidophilus.

PubMed

Gao, Yan; Jiang, Xiaoqiong; Lin, Dongjia; Chen, Yanhuo; Tong, Zhongchun

2016-08-01

Enterococcus faecalis is the most frequently detected species in root canal-treated teeth, and it is able to survive under starvation conditions. However, persistent periapical disease is often caused by multispecies. The aim of this study was to explore the survival of E. faecalis in starvation conditions and biofilm formation with the 4 common pathogenic species. A dual-species model of Candida albicans, Streptococcus gordonii, Actinomyces viscosus, or Lactobacillus acidophilus in combination with E. faecalis was established and allowed to grow in phosphate-buffered saline for the examination of starvation survival. Cefuroxime sodium and vancomycin at a concentration of 100 mg/L were added into brain-heart infusion plate agar to count the 2 bacteria separately in the dual species. Scanning electron microscopy was used to observe the dual species and multiple species on the root canal dentin of bovine teeth for 48 hours. A confocal laser scanning microscope was used to show the 4 groups of dual-species biofilms on substrates with glass bottoms for 48 hours. E. faecalis was more resistant to starvation in coexistence with C. albicans, S. gordonii, A. viscosus, or L. acidophilus, and S. gordonii was completely inhibited in coexistence with E. faecalis. The dual-species biofilm showed that E. faecalis formed thicker and denser biofilms on the root canal dentin and glass slides in coexistence with S. gordonii and A. viscosus than C. albicans and L. acidophilus. The multispecies community is conducive to the resistance to starvation of E. faecalis and biofilm formation in root canals. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Diagnostic Efficiency in Digital Pathology: A Comparison of Optical Versus Digital Assessment in 510 Surgical Pathology Cases.

PubMed

Mills, Anne M; Gradecki, Sarah E; Horton, Bethany J; Blackwell, Rebecca; Moskaluk, Christopher A; Mandell, James W; Mills, Stacey E; Cathro, Helen P

2018-01-01

Prior work has shown that digital images and microscopic slides can be interpreted with comparable diagnostic accuracy. Although accuracy has been well-validated, the interpretative time for digital images has scarcely been studied and concerns about efficiency remain a major barrier to adoption. We investigated the efficiency of digital pathology when compared with glass slide interpretation in the diagnosis of surgical pathology biopsy and resection specimens. Slides were pulled from 510 surgical pathology cases from 5 organ systems (gastrointestinal, gynecologic, liver, bladder, and brain). Original diagnoses were independently confirmed by 2 validating pathologists. Diagnostic slides were scanned using the Philips IntelliSite Pathology Solution. Each case was assessed independently on digital and optical by 3 reading pathologists, with a ≥6 week washout period between modalities. Reading pathologists recorded assessment times for each modality; digital times included time to load the case. Diagnostic accuracy was determined based on whether a rendered diagnosis differed significantly from the original diagnosis. Statistical analysis was performed to assess for differences in interpretative times across modalities. All 3 reading pathologists showed comparable diagnostic accuracy across optical and digital modalities (mean major discordance rates with original diagnosis: 4.8% vs. 4.4%, respectively). Mean assessment times ranged from 1.2 to 9.1 seconds slower on digital versus optical. The slowest reader showed a significant learning effect during the course of the study so that digital assessment times decreased over time and were comparable with optical times by the end of the series. Organ site and specimen type did not significantly influence differences in interpretative times. In summary, digital image reading times compare favorably relative to glass slides across a variety of organ systems and specimen types. Mean increase in assessment time is 4 seconds/case. This time can be minimized with experience and may be further balanced by the improved ease of electronic chart access allowed by digital slide viewing, as well as quantitative assessments which can be expedited on digital images.

Objective detection of apoptosis in rat renal tissue sections using light microscopy and free image analysis software with subsequent machine learning: Detection of apoptosis in renal tissue.

PubMed

Macedo, Nayana Damiani; Buzin, Aline Rodrigues; de Araujo, Isabela Bastos Binotti Abreu; Nogueira, Breno Valentim; de Andrade, Tadeu Uggere; Endringer, Denise Coutinho; Lenz, Dominik

2017-02-01

The current study proposes an automated machine learning approach for the quantification of cells in cell death pathways according to DNA fragmentation. A total of 17 images of kidney histological slide samples from male Wistar rats were used. The slides were photographed using an Axio Zeiss Vert.A1 microscope with a 40x objective lens coupled with an Axio Cam MRC Zeiss camera and Zen 2012 software. The images were analyzed using CellProfiler (version 2.1.1) and CellProfiler Analyst open-source software. Out of the 10,378 objects, 4970 (47,9%) were identified as TUNEL positive, and 5408 (52,1%) were identified as TUNEL negative. On average, the sensitivity and specificity values of the machine learning approach were 0.80 and 0.77, respectively. Image cytometry provides a quantitative analytical alternative to the more traditional qualitative methods more commonly used in studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Spirochaetemia in a HIV positive patient.

PubMed

Okwori, E E

2006-01-01

Borreliosis, caused by Borrelia recurrentis and several other Borrelia species is not a commonly reported case in our environment, but the search for the cause of recurrent pyrexia in this patient made it possible to discover the spirochete as the cause of the disease. A 38 year old married HIV positive woman presented with recurrent fever in a private clinic. Six thin smears were made out of the patient serum and dried in the air. Three slides each were stained with 0.12% Leishman and 20% Giemsa stains and examined under the light microscope. Three of the Giemsa slides were positive for spirochetes (4-5 spirals), which were constituents with Borrelia species. The patient responded very well to tetracycline and serum became negative for the organism after ten days of treatment. Borrelia was discovered to be the cause of the recurrent pyrexia in this patient who responded very well to tetracycline. Borrelia should be looked for in cases of pyrexia of unknown origin

Localized removal of layers of metal, polymer, or biomaterial by ultrasound cavitation bubbles

PubMed Central

Fernandez Rivas, David; Verhaagen, Bram; Seddon, James R. T.; Zijlstra, Aaldert G.; Jiang, Lei-Meng; van der Sluis, Luc W. M.; Versluis, Michel; Lohse, Detlef; Gardeniers, Han J. G. E.

2012-01-01

We present an ultrasonic device with the ability to locally remove deposited layers from a glass slide in a controlled and rapid manner. The cleaning takes place as the result of cavitating bubbles near the deposited layers and not due to acoustic streaming. The bubbles are ejected from air-filled cavities micromachined in a silicon surface, which, when vibrated ultrasonically at a frequency of 200 kHz, generate a stream of bubbles that travel to the layer deposited on an opposing glass slide. Depending on the pressure amplitude, the bubble clouds ejected from the micropits attain different shapes as a result of complex bubble interaction forces, leading to distinct shapes of the cleaned areas. We have determined the removal rates for several inorganic and organic materials and obtained an improved efficiency in cleaning when compared to conventional cleaning equipment. We also provide values of the force the bubbles are able to exert on an atomic force microscope tip. PMID:23964308

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

Ay, H.; Özyurek, D.; Yıldırım, M., E-mail: musayildirim@karabuk.edu.tr

In this study, the wear properties of in-situ 7075 Al-Ti composites produced by powder metallurgy route were investigated. Different amount of Ti (2, 4, 6 %) added to gas atomized 7075 Al alloy powders and they were mixed in turbula with 47rpm for 45 minutes. Then the mixed powders were pre-shaped by press under 600 MPa pressure. The samples were cooled in the furnace after sintered at 580 °C for 4 hours in the atmosphere controlled furnace. Standard metallographic process such as grinding, polishing and etching were applied to sintered samples. The hardness values were measured. Scanning Electron Microscope (SEM), X-Raymore » Diffraction (XRD) examines were carried out. The wear tests were performed in a pin-on disc type wear apparatus with 1 ms{sup −1} sliding speed at six different sliding distance (500-3000 m) under 30 N loads. As a result of studies, hardness values were increased with increasing Ti content, in addition the weight losses were decreased with increasing Ti amount.« less

The Project Of Another Low-Cost Metaphase Finder.

PubMed

Furukawa, Akira

2016-12-01

The most popular and 'gold standard' phenomenon in Biological dosimetry is the appearance of dicentric chromosomes in metaphase in white blood cells. The metaphase finder is a tool for biological dosimetry that finds metaphase cells on slide glasses. The author and a software company were using new special software that was faster than conventional systems. A Nikon Eclipse Ni-E microscope with motorised X-Y stage, 4× objective lens and 1920 × 1024 pixels colour camera for hardware were used. The software uses mathematical morphology filters. The new system was compact and low-priced. And the remarkable point is, this system can be applicable not only to human blood, but also to non-human samples. The speed was 208-236 s per 5 × 20 mm area, while capturing 378 images, which achieved the aim of the project. The false-positive ratio achieved below 5% in some slides. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Gene chips and arrays revealed: a primer on their power and their uses.

PubMed

Watson, S J; Akil, H

1999-03-01

This article provides an overview and general explanation of the rapidly developing area of gene chips and expression array technology. These are methods targeted at allowing the simultaneous study of thousands of genes or messenger RNAs under various physiological and pathological states. Their technical basis grows from the Human Genome Project. Both methods place DNA strands on glass computer chips (or microscope slides). Expression arrays start with complementary DNA (cDNA) clones derived from the EST data base, whereas Gene Chips synthesize oligonucleotides directly on the chip itself. Both are analyzed using image analysis systems, are capable of reading values from two different individuals at any one site, and can yield quantitative data for thousands of genes or mRNAs per slide. These methods promise to revolutionize molecular biology, cell biology, neuroscience and psychiatry. It is likely that this technology will radically open up our ability to study the actions and structure of the multiple genes involved in the complex genetics of brain disorders.

Structural properties 3,16-bis triisopropylsilylethynyl (pentacene) (TIPS-pentacene) thin films onto organic dielectric layer using slide coating method

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

Rusnan, Fara Naila; Mohamad, Khairul Anuar; Seria, Dzul Fahmi Mohd Husin

3,16-bis triisopropylsilylethynyl (Pentacene) (TIPS-Pentacene) compactable interface property is important in order to have a good arrangement of molecular structure. Comparison for TIPS-Pentacene deposited between two different surface layers conducted. 0.1wt% TIPS-Pentacene diluted in chloroform were deposited onto poly(methylmeaclyrate) (PMMA) layered transparent substrates using slide coating method. X-ray diffraction (XRD) used to determine crystallinity of thin films. Series of (00l) diffraction peaks obtained with sharp first peaks (001) for TIPS-Pentacene deposited onto PMMA layer at 5.35° and separation of 16.3 Å. Morphology and surface roughness were carried out using scanning electron microscope (SEM) and surface profilemeter LS500, respectively.TIPS-Pentacene deposited onto PMMAmore » layer formed needled-like-shape grains with 10.26 nm surface roughness. These properties were related as thin film formed and its surface roughness plays important role towards good mobility devices.« less

Switchable friction enabled by nanoscale self-assembly on graphene

DOE PAGES

Gallagher, Patrick; Lee, Menyoung; Amet, Francois; ...

2016-02-23

Graphene monolayers are known to display domains of anisotropic friction with twofold symmetry and anisotropy exceeding 200%. This anisotropy has been thought to originate from periodic nanoscale ripples in the graphene sheet, which enhance puckering around a sliding asperity to a degree determined by the sliding direction. Here we demonstrate that these frictional domains derive not from structural features in the graphene but from self-assembly of environmental adsorbates into a highly regular superlattice of stripes with period 4–6 nm. The stripes and resulting frictional domains appear on monolayer and multilayer graphene on a variety of substrates, as well as onmore » exfoliated flakes of hexagonal boron nitride. We show that the stripe-superlattices can be reproducibly and reversibly manipulated with submicrometre precision using a scanning probe microscope, allowing us to create arbitrary arrangements of frictional domains within a single flake. In conclusion, our results suggest a revised understanding of the anisotropic friction observed on graphene and bulk graphite in terms of adsorbates.« less

Online teaching of inflammatory skin pathology by a French-speaking International University Network

PubMed Central

2014-01-01

Introduction Developments in technology, web-based teaching and whole slide imaging have broadened the teaching horizon in anatomic pathology. Creating online learning material including many types of media such as radiologic images, whole slides, videos, clinical and macroscopic photographs, is now accessible to most universities. Unfortunately, a major limiting factor to maintain and update the learning material is the amount of resources needed. In this perspective, a French-national university network was initiated in 2011 to build joint online teaching modules consisting of clinical cases and tests. The network has since expanded internationally to Québec, Switzerland and Ivory Coast. Method One of the first steps of the project was to build a learning module on inflammatory skin pathology for interns and residents in pathology and dermatology. A pathology resident from Québec spent 6 weeks in France and Switzerland to develop the contents and build the module on an e-learning Moodle platform under the supervision of two dermatopathologists. The learning module contains text, interactive clinical cases, tests with feedback, virtual slides, images and clinical photographs. For that module, the virtual slides are decentralized in 2 universities (Bordeaux and Paris 7). Each university is responsible of its own slide scanning, image storage and online display with virtual slide viewers. Results The module on inflammatory skin pathology includes more than 50 web pages with French original content, tests and clinical cases, links to over 45 virtual images and more than 50 microscopic and clinical photographs. The whole learning module is being revised by four dermatopathologists and two senior pathologists. It will be accessible to interns and residents in the spring of 2014. The experience and knowledge gained from that work will be transferred to the next international resident whose work will be aimed at creating lung and breast pathology learning modules. Conclusion The challenges of sustaining a project of this scope are numerous. The technical aspect of whole-slide imaging and storage needs to be developed by each university or group. The content needs to be regularly updated and its accuracy reviewed by experts in each individual domain. The learning modules also need to be promoted within the academic community to ensure maximal benefit for trainees. A collateral benefit of the project was the establishment of international partnerships between French-speaking universities and pathologists with the common goal of promoting pathology education through the use of multi-media technology including whole slide imaging. PMID:25564778

Online teaching of inflammatory skin pathology by a French-speaking International University Network.

PubMed

Perron, Emilie; Battistella, Maxime; Vergier, Béatrice; Fiche, Maryse; Bertheau, Philippe; Têtu, Bernard

2014-01-01

Developments in technology, web-based teaching and whole slide imaging have broadened the teaching horizon in anatomic pathology. Creating online learning material including many types of media such as radiologic images, whole slides, videos, clinical and macroscopic photographs, is now accessible to most universities. Unfortunately, a major limiting factor to maintain and update the learning material is the amount of resources needed. In this perspective, a French-national university network was initiated in 2011 to build joint online teaching modules consisting of clinical cases and tests. The network has since expanded internationally to Québec, Switzerland and Ivory Coast. One of the first steps of the project was to build a learning module on inflammatory skin pathology for interns and residents in pathology and dermatology. A pathology resident from Québec spent 6 weeks in France and Switzerland to develop the contents and build the module on an e-learning Moodle platform under the supervision of two dermatopathologists. The learning module contains text, interactive clinical cases, tests with feedback, virtual slides, images and clinical photographs. For that module, the virtual slides are decentralized in 2 universities (Bordeaux and Paris 7). Each university is responsible of its own slide scanning, image storage and online display with virtual slide viewers. The module on inflammatory skin pathology includes more than 50 web pages with French original content, tests and clinical cases, links to over 45 virtual images and more than 50 microscopic and clinical photographs. The whole learning module is being revised by four dermatopathologists and two senior pathologists. It will be accessible to interns and residents in the spring of 2014. The experience and knowledge gained from that work will be transferred to the next international resident whose work will be aimed at creating lung and breast pathology learning modules. The challenges of sustaining a project of this scope are numerous. The technical aspect of whole-slide imaging and storage needs to be developed by each university or group. The content needs to be regularly updated and its accuracy reviewed by experts in each individual domain. The learning modules also need to be promoted within the academic community to ensure maximal benefit for trainees. A collateral benefit of the project was the establishment of international partnerships between French-speaking universities and pathologists with the common goal of promoting pathology education through the use of multi-media technology including whole slide imaging.

Live-Cell Imaging of Protease Activity: Assays to Screen Therapeutic Approaches.

PubMed

Chalasani, Anita; Ji, Kyungmin; Sameni, Mansoureh; Mazumder, Samia H; Xu, Yong; Moin, Kamiar; Sloane, Bonnie F

2017-01-01

Methodologies to image and quantify the activity of proteolytic enzymes have been developed in an effort to identify protease-related druggable pathways that are involved in malignant progression of cancer. Our laboratory has pioneered techniques for functional live-cell imaging of protease activity in pathomimetic avatars for breast cancer. We analyze proteolysis in the context of proliferation and formation of structures by tumor cells in 3-D cultures over time (4D). In order to recapitulate the cellular composition and architecture of tumors in the pathomimetic avatars, we include other tumor-associated cells (e.g., fibroblasts, myoepithelial cells, microvascular endothelial cells). We also model noncellular aspects of the tumor microenvironment such as acidic pericellular pH. Use of pathomimetic avatars in concert with various types of imaging probes has allowed us to image, quantify, and follow the dynamics of proteolysis in the tumor microenvironment and to test interventions that impact directly or indirectly on proteolytic pathways. To facilitate use of the pathomimetic avatars for screening of therapeutic modalities, we have designed and fabricated custom 3D culture chambers with multiple wells that are either individual or connected by a channel to allow cells to migrate between wells. Optical glass microscope slides underneath an acrylic plate allow the cultures to be imaged with an inverted microscope. Fluid ports in the acrylic plate are at a level above the 3D cultures to allow introduction of culture media and test agents such as drugs into the wells and the harvesting of media conditioned by the cultures for immunochemical and biochemical analyses. We are using the pathomimetic avatars to identify druggable pathways, screen drug and natural product libraries and accelerate entry of validated drugs or natural products into clinical trials.

Informatics for practicing anatomical pathologists: marking a new era in pathology practice.

PubMed

Gabril, Manal Y; Yousef, George M

2010-03-01

Informatics can be defined as using highly advanced technologies to improve patient diagnosis or management. Pathology informatics had evolved as a response to the overwhelming amount of information that was available, in an attempt to better use and maintain them. The most commonly used tools of informatics can be classified into digital imaging, telepathology, as well as Internet and electronic data mining. Digital imaging is the storage of anatomical pathology information, either gross pictures or microscopic slides, in an electronic format. These images can be used for education, archival, diagnosis, and consultation. Virtual microscopy is the more advanced form of digital imaging with enhanced efficiency and accessibility. Telepathology is now increasingly becoming a useful tool in anatomical pathology practice. Different types of telepathology communications are available for both diagnostic and consultation services. The spectrum of applications of informatics in the field of anatomical pathology is broad and encompasses medical education, clinical services, and pathology research. Informatics is now settling on solid ground as an important tool for pathology teaching, with digital teaching becoming the standard tool in many institutions. After a slow start, we now witness the transition of informatics from the research bench to bedside. As we are moving into a new era of extensive pathology informatics utilization, several challenges have to be addressed, including the cost of the new technology, legal issues, and resistance of pathologists. It is clear from the current evidence that pathology informatics will continue to grow and have a major role in the future of our specialty. However, it is also clear that it is not going to fully replace the human factor or the regular microscope.

Comparative Cytogenetic Study on the Toxicity of Magnetite and Zinc Ferrite Nanoparticles in Sunflower Root Cells

NASA Astrophysics Data System (ADS)

Foca-nici, Ecaterina; Capraru, Gabriela; Creanga, Dorina

2010-12-01

In this experimental study the authors present their results regarding the cellular division rate and the percentage of chromosomal aberrations in the root meristematic cells of Helianthus annuus cultivated in the presence of different volume fractions of magnetic nanoparticle suspensions, ranging between 20 and 100 microl/l. The aqueous magnetic colloids were prepared from chemically co-precipitated ferrites coated in sodium oleate. Tissue samples from the root meristeme of 2-3 day old germinated seeds were taken to prepare microscope slides following Squash method combined with Fuelgen techniques. Microscope investigation (cytogenetic tests) has resulted in the evaluation of mitotic index and chromosomal aberration index that appeared diminished and respectively increased following the addition of magnetic nanoparticles in the culture medium of the young seedlings. Zinc ferrite toxic influence appeared to be higher than that of magnetite, according to both cytogenetic parameters.

Offset-sparsity decomposition for enhancement of color microscopic image of stained specimen in histopathology: further results

NASA Astrophysics Data System (ADS)

Kopriva, Ivica; Popović Hadžija, Marijana; Hadžija, Mirko; Aralica, Gorana

2016-03-01

Recently, novel data-driven offset-sparsity decomposition (OSD) method was proposed by us to increase colorimetric difference between tissue-structures present in the color microscopic image of stained specimen in histopathology. The OSD method performs additive decomposition of vectorized spectral images into image-adapted offset term and sparse term. Thereby, the sparse term represents an enhanced image. The method was tested on images of the histological slides of human liver stained with hematoxylin and eosin, anti-CD34 monoclonal antibody and Sudan III. Herein, we present further results related to increase of colorimetric difference between tissue structures present in the images of human liver specimens with pancreatic carcinoma metastasis stained with Gomori, CK7, CDX2 and LCA, and with colon carcinoma metastasis stained with Gomori, CK20 and PAN CK. Obtained relative increase of colorimetric difference is in the range [19.36%, 103.94%].