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Sample records for advanced molecular techniques

  1. Advanced techniques for constrained internal coordinate molecular dynamics.

    PubMed

    Wagner, Jeffrey R; Balaraman, Gouthaman S; Niesen, Michiel J M; Larsen, Adrien B; Jain, Abhinandan; Vaidehi, Nagarajan

    2013-04-30

    Internal coordinate molecular dynamics (ICMD) methods provide a more natural description of a protein by using bond, angle, and torsional coordinates instead of a Cartesian coordinate representation. Freezing high-frequency bonds and angles in the ICMD model gives rise to constrained ICMD (CICMD) models. There are several theoretical aspects that need to be developed to make the CICMD method robust and widely usable. In this article, we have designed a new framework for (1) initializing velocities for nonindependent CICMD coordinates, (2) efficient computation of center of mass velocity during CICMD simulations, (3) using advanced integrators such as Runge-Kutta, Lobatto, and adaptive CVODE for CICMD simulations, and (4) cancelling out the "flying ice cube effect" that sometimes arises in Nosé-Hoover dynamics. The Generalized Newton-Euler Inverse Mass Operator (GNEIMO) method is an implementation of a CICMD method that we have developed to study protein dynamics. GNEIMO allows for a hierarchy of coarse-grained simulation models based on the ability to rigidly constrain any group of atoms. In this article, we perform tests on the Lobatto and Runge-Kutta integrators to determine optimal simulation parameters. We also implement an adaptive coarse-graining tool using the GNEIMO Python interface. This tool enables the secondary structure-guided "freezing and thawing" of degrees of freedom in the molecule on the fly during molecular dynamics simulations and is shown to fold four proteins to their native topologies. With these advancements, we envision the use of the GNEIMO method in protein structure prediction, structure refinement, and in studying domain motion. PMID:23345138

  2. Vibrio parahaemolyticus: a review on the pathogenesis, prevalence, and advance molecular identification techniques

    PubMed Central

    Letchumanan, Vengadesh; Chan, Kok-Gan; Lee, Learn-Han

    2014-01-01

    Vibrio parahaemolyticus is a Gram-negative halophilic bacterium that is found in estuarine, marine and coastal environments. V. parahaemolyticus is the leading causal agent of human acute gastroenteritis following the consumption of raw, undercooked, or mishandled marine products. In rare cases, V. parahaemolyticus causes wound infection, ear infection or septicaemia in individuals with pre-existing medical conditions. V. parahaemolyticus has two hemolysins virulence factors that are thermostable direct hemolysin (tdh)-a pore-forming protein that contributes to the invasiveness of the bacterium in humans, and TDH-related hemolysin (trh), which plays a similar role as tdh in the disease pathogenesis. In addition, the bacterium is also encodes for adhesions and type III secretion systems (T3SS1 and T3SS2) to ensure its survival in the environment. This review aims at discussing the V. parahaemolyticus growth and characteristics, pathogenesis, prevalence and advances in molecular identification techniques. PMID:25566219

  3. 3. Advanced Polymer Molecular Science

    E-print Network

    Duh, Kevin

    3. Advanced Polymer Molecular Science Advanced Polymer Science 4. Photo-Functional Elements Supplies with New Functions Achieved with Artificial Collagen and Nano-structured Polymers Biocompatible. Organic Semi- conducting Polymer Creation through Precursor Methods Photofunctional Organic Chemistry

  4. Detecting the dormant: a review of recent advances in molecular techniques for assessing the viability of bacterial endospores.

    PubMed

    Mohapatra, Bidyut R; La Duc, Myron T

    2013-09-01

    Due to their contribution to gastrointestinal and pulmonary disease, their ability to produce various deadly exotoxins, and their resistance to extreme temperature, pressure, radiation, and common chemical disinfecting agents, bacterial endospores of the Firmicutes phylum are a major concern for public and environmental health. In addition, the hardy and dormant nature of endospores renders them a particularly significant threat to the integrity of robotic extraterrestrial life-detection investigations. To prevent the contamination of critical surfaces with seemingly ubiquitous bacterial endospores, clean rooms maintained at exceedingly stringent cleanliness levels (i.e., fewer than 100,000 airborne particles per ft(3)) are used for surgical procedures, pharmaceutical processing and packaging, and fabrication and assembly of medical devices and spacecraft components. However, numerous spore-forming bacterial species have been reported to withstand typical clean room bioreduction strategies (e.g., UV lights, maintained humidity, paucity of available nutrients), which highlights the need for rapid and reliable molecular methods for detecting, enumerating, and monitoring the incidence of viable endospores. Robust means of evaluating and tracking spore burden not only provide much needed information pertaining to endospore ecophysiology in different environmental niches but also empower decontamination and bioreduction strategies aimed at sustaining the reliability and integrity of clean room environments. An overview of recent molecular advances in detecting and enumerating viable endospores, as well as the expanding phylogenetic diversity of pathogenic and clean room-associated spore-forming bacteria, ensues. PMID:23912118

  5. 3. Advanced Polymer Molecular Science

    E-print Network

    Duh, Kevin

    3. Advanced Polymer Molecular Science Advanced Polymer Science 4. Photo-Functional Elements at the Center of Advanced Technology Photonic Device Science 5. Research on Functional Information Elements supporting the Next-generation Information Society Information Device Science EL 6. Energy Electronic

  6. Advanced radiographic imaging techniques.

    NASA Technical Reports Server (NTRS)

    Beal, J. B.; Brown, R. L.

    1973-01-01

    Examination of the nature and operational constraints of conventional X-radiographic and neutron imaging methods, providing a foundation for a discussion of advanced radiographic imaging systems. Two types of solid-state image amplifiers designed to image X rays are described. Operational theory, panel construction, and performance characteristics are discussed. A closed-circuit television system for imaging neutrons is then described and the system design, operational theory, and performance characteristics are outlined. Emphasis is placed on a description of the advantages of these imaging systems over conventional methods.

  7. Advanced Power Estimation Techniques MASSOUD PEDRAM

    E-print Network

    Pedram, Massoud

    Advanced Power Estimation Techniques MASSOUD PEDRAM University of Southern California Department of Electrical Engineering { Systems Los Angeles, CA 90089 massoud@zugros.usc.edu This chapter describes

  8. Signature molecular descriptor : advanced applications.

    SciTech Connect

    Visco, Donald Patrick, Jr.

    2010-04-01

    In this work we report on the development of the Signature Molecular Descriptor (or Signature) for use in the solution of inverse design problems as well as in highthroughput screening applications. The ultimate goal of using Signature is to identify novel and non-intuitive chemical structures with optimal predicted properties for a given application. We demonstrate this in three studies: green solvent design, glucocorticoid receptor ligand design and the design of inhibitors for Factor XIa. In many areas of engineering, compounds are designed and/or modified in incremental ways which rely upon heuristics or institutional knowledge. Often multiple experiments are performed and the optimal compound is identified in this brute-force fashion. Perhaps a traditional chemical scaffold is identified and movement of a substituent group around a ring constitutes the whole of the design process. Also notably, a chemical being evaluated in one area might demonstrate properties very attractive in another area and serendipity was the mechanism for solution. In contrast to such approaches, computer-aided molecular design (CAMD) looks to encompass both experimental and heuristic-based knowledge into a strategy that will design a molecule on a computer to meet a given target. Depending on the algorithm employed, the molecule which is designed might be quite novel (re: no CAS registration number) and/or non-intuitive relative to what is known about the problem at hand. While CAMD is a fairly recent strategy (dating to the early 1980s), it contains a variety of bottlenecks and limitations which have prevented the technique from garnering more attention in the academic, governmental and industrial institutions. A main reason for this is how the molecules are described in the computer. This step can control how models are developed for the properties of interest on a given problem as well as how to go from an output of the algorithm to an actual chemical structure. This report provides details on a technique to describe molecules on a computer, called Signature, as well as the computer-aided molecule design algorithm built around Signature. Two applications are provided of the CAMD algorithm with Signature. The first describes the design of green solvents based on data in the GlaxoSmithKline (GSK) Solvent Selection Guide. The second provides novel non-steroidal glucocorticoid receptor ligands with some optimally predicted properties. In addition to using the CAMD algorithm with Signature, it is demonstrated how to employ Signature in a high-throughput screening study. Here, after classifying both active and inactive inhibitors for the protein Factor XIa using Signature, the model developed is used to screen a large, publicly-available database called PubChem for the most active compounds.

  9. Advanced Spectroscopy Technique for Biomedicine

    NASA Astrophysics Data System (ADS)

    Zhao, Jianhua; Zeng, Haishan

    This chapter presents an overview of the applications of optical spectroscopy in biomedicine. We focus on the optical design aspects of advanced biomedical spectroscopy systems, Raman spectroscopy system in particular. Detailed components and system integration are provided. As examples, two real-time in vivo Raman spectroscopy systems, one for skin cancer detection and the other for endoscopic lung cancer detection, and an in vivo confocal Raman spectroscopy system for skin assessment are presented. The applications of Raman spectroscopy in cancer diagnosis of the skin, lung, colon, oral cavity, gastrointestinal tract, breast, and cervix are summarized.

  10. Stitching Techniques Advance Optics Manufacturing

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Because NASA depends on the fabrication and testing of large, high-quality aspheric (nonspherical) optics for applications like the James Webb Space Telescope, it sought an improved method for measuring large aspheres. Through Small Business Innovation Research (SBIR) awards from Goddard Space Flight Center, QED Technologies, of Rochester, New York, upgraded and enhanced its stitching technology for aspheres. QED developed the SSI-A, which earned the company an R&D 100 award, and also developed a breakthrough machine tool called the aspheric stitching interferometer. The equipment is applied to advanced optics in telescopes, microscopes, cameras, medical scopes, binoculars, and photolithography."

  11. Advancing disease mapping techniques with GSK

    E-print Network

    Advancing disease mapping techniques with GSK Healthcare company GSK is using the STFC Hartree Centre's intense computing expertise to identify connections between different genes and diseases in the progression of a disease can provide the key to developing a treatment or cure, and also to identifying new

  12. [Advances in cardiovascular medicine through molecular imaging].

    PubMed

    Nahrendorf, M; Weissleder, R

    2007-01-01

    We will witness a change of paradigm in cardiovascular imaging, which is empowered by advances in imaging technology, biochemistry, molecular biology and nanotechnology. Instead of simply following the physical distribution of established contrast agents, we now have the opportunity to noninvasively image biological processes such as enzyme activity, interaction with cell surface markers, gene expression and cell migration. These advancements open up new avenues in basic cardiovascular research and will greatly speed up the pace of discovery. Patient management will profit as well: cardiovascular molecular imaging will strengthen personlized and prophylactic medicine through timely and precise diagnostics. In our review we describe selected molecular imaging strategies in atherosclerosis, myocardial ischemia and healing. PMID:17187263

  13. Advanced Molecular Surveillance of Hepatitis C Virus

    PubMed Central

    Gonçalves Rossi, Livia Maria; Escobar-Gutierrez, Alejandro; Rahal, Paula

    2015-01-01

    Hepatitis C virus (HCV) infection is an important public health problem worldwide. HCV exploits complex molecular mechanisms, which result in a high degree of intrahost genetic heterogeneity. This high degree of variability represents a challenge for the accurate establishment of genetic relatedness between cases and complicates the identification of sources of infection. Tracking HCV infections is crucial for the elucidation of routes of transmission in a variety of settings. Therefore, implementation of HCV advanced molecular surveillance (AMS) is essential for disease control. Accounting for virulence is also important for HCV AMS and both viral and host factors contribute to the disease outcome. Therefore, HCV AMS requires the incorporation of host factors as an integral component of the algorithms used to monitor disease occurrence. Importantly, implementation of comprehensive global databases and data mining are also needed for the proper study of the mechanisms responsible for HCV transmission. Here, we review molecular aspects associated with HCV transmission, as well as the most recent technological advances used for virus and host characterization. Additionally, the cornerstone discoveries that have defined the pathway for viral characterization are presented and the importance of implementing advanced HCV molecular surveillance is highlighted. PMID:25781918

  14. Molecular dynamics simulations: advances and applications

    PubMed Central

    Hospital, Adam; Goñi, Josep Ramon; Orozco, Modesto; Gelpí, Josep L

    2015-01-01

    Molecular dynamics simulations have evolved into a mature technique that can be used effectively to understand macromolecular structure-to-function relationships. Present simulation times are close to biologically relevant ones. Information gathered about the dynamic properties of macromolecules is rich enough to shift the usual paradigm of structural bioinformatics from studying single structures to analyze conformational ensembles. Here, we describe the foundations of molecular dynamics and the improvements made in the direction of getting such ensemble. Specific application of the technique to three main issues (allosteric regulation, docking, and structure refinement) is discussed. PMID:26604800

  15. Advanced techniques for MRI of atherosclerotic plaque.

    PubMed

    Kerwin, William S; Canton, Gador

    2009-08-01

    This review examines the state of the art in vessel wall imaging by magnetic resonance imaging (MRI) with an emphasis on the biomechanical assessment of atherosclerotic plaque. Three areas of advanced techniques are discussed. First, alternative contrast mechanisms, including susceptibility, magnetization transfer, diffusion, and perfusion, are presented as to how they facilitate accurate determination of plaque constituents underlying biomechanics. Second, imaging technologies including hardware and sequences, are reviewed as to how they provide the resolution and signal-to-noise ratio necessary for determining plaque structure. Finally, techniques for combining MRI data into an overall assessment of plaque biomechanical properties, including wall shear stress and internal plaque strain, are presented. The paper closes with a discussion of the extent to which these techniques have been applied to different arteries commonly targeted by vessel wall MRI. PMID:20805732

  16. Insect pathogens: molecular approaches and techniques

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This book serves as a primer for molecular techniques in insect pathology and is tailored for a wide scientific audience. Contributing authors are internationally recognized experts. The book comprises four sections: 1) pathogen identification and diagnostics, 2) pathogen population genetics and p...

  17. Advanced Tools and Techniques for Formal Techniques in Aerospace Systems

    NASA Technical Reports Server (NTRS)

    Knight, John C.

    2005-01-01

    This is the final technical report for grant number NAG-1-02101. The title of this grant was "Advanced Tools and Techniques for Formal Techniques In Aerospace Systems". The principal investigator on this grant was Dr. John C. Knight of the Computer Science Department, University of Virginia, Charlottesville, Virginia 22904-4740. This report summarizes activities under the grant during the period 7/01/2002 to 9/30/2004. This report is organized as follows. In section 2, the technical background of the grant is summarized. Section 3 lists accomplishments and section 4 lists students funded under the grant. In section 5, we present a list of presentations given at various academic and research institutions about the research conducted. Finally, a list of publications generated under this grant is included in section 6.

  18. Advanced Bode Plot Techniques for Ultrasonic Transducers

    NASA Astrophysics Data System (ADS)

    DeAngelis, D. A.; Schulze, G. W.

    The Bode plot, displayed as either impedance or admittance versus frequency, is the most basic test used by ultrasonic transducer designers. With simplicity and ease-of-use, Bode plots are ideal for baseline comparisons such as spacing of parasitic modes or impedance, but quite often the subtleties that manifest as poor process control are hard to interpret or are nonexistence. In-process testing of transducers is time consuming for quantifying statistical aberrations, and assessments made indirectly via the workpiece are difficult. This research investigates the use of advanced Bode plot techniques to compare ultrasonic transducers with known "good" and known "bad" process performance, with the goal of a-priori process assessment. These advanced techniques expand from the basic constant voltage versus frequency sweep to include constant current and constant velocity interrogated locally on transducer or tool; they also include up and down directional frequency sweeps to quantify hysteresis effects like jumping and dropping phenomena. The investigation focuses solely on the common PZT8 piezoelectric material used with welding transducers for semiconductor wire bonding. Several metrics are investigated such as impedance, displacement/current gain, velocity/current gain, displacement/voltage gain and velocity/voltage gain. The experimental and theoretical research methods include Bode plots, admittance loops, laser vibrometry and coupled-field finite element analysis.

  19. Advances in nanodiagnostic techniques for microbial agents.

    PubMed

    Syed, Muhammad Ali

    2014-01-15

    Infectious diseases account for millions of sufferings and deaths in both developing as well as developed countries with a substantial economic loss. Massive increase in world population and international travel has facilitated their spread from one part of the world to other areas, making them one of the most significant global health risks. Furthermore, detection of bioterrorism agents in water, food and environmental samples as well traveler's baggage is a great challenge of the time for security purpose. Prevention strategies against infectious agents demand rapid and accurate detection and identification of the causative agents with highest sensitivity which should be equally available in different parts of the globe. Similarly, rapid and early diagnosis of infectious diseases has always been indispensable for their prompt cure and management, which has stimulated scientists to develop highly sophisticated techniques over centuries and the efforts continue unabated. Conventional diagnostic techniques are time consuming, tedious, expensive, less sensitive, and unsuitable for field situations. Nanodiagnostic assays have been promising for early, sensitive, point-of-care and cost-effective detection of microbial agents. There has been an explosive research in this area of science in last two decades yielding highly fascinating results. This review highlights some of the advancements made in the field of nanotechnology based assays for microbial detection since 2005 along with providing the basic understanding. PMID:24012709

  20. Inverse lithography technique for advanced CMOS nodes

    NASA Astrophysics Data System (ADS)

    Villaret, Alexandre; Tritchkov, Alexander; Entradas, Jorge; Yesilada, Emek

    2013-04-01

    Resolution Enhancement Techniques have continuously improved over the last decade, driven by the ever growing constraints of lithography process. Despite the large number of RET applied, some hotspot configurations remain challenging for advanced nodes due to aggressive design rules. Inverse Lithography Technique (ILT) is evaluated here as a substitute to the dense OPC baseline. Indeed ILT has been known for several years for its near-to-ideal mask quality, while also being potentially more time consuming in terms of OPC run and mask processing. We chose to evaluate Mentor Graphics' ILT engine "pxOPCTM" on both lines and via hotspot configurations. These hotspots were extracted from real 28nm test cases where the dense OPC solution is not satisfactory. For both layer types, the reference OPC consists of a dense OPC engine coupled to rule-based and/or model-based assist generation method. The same CM1 model is used for the reference and the ILT OPC. ILT quality improvement is presented through Optical Rule Check (ORC) results with various adequate detectors. Several mask manufacturing rule constraints (MRC) are considered for the ILT solution and their impact on process ability is checked after mask processing. A hybrid OPC approach allowing localized ILT usage is presented in order to optimize both quality and runtime. A real mask is prepared and fabricated with this method. Finally, results analyzed on silicon are presented to compare localized ILT to reference dense OPC.

  1. Molecular imaging of rheumatoid arthritis: emerging markers, tools, and techniques

    PubMed Central

    2014-01-01

    Early diagnosis and effective monitoring of rheumatoid arthritis (RA) are important for a positive outcome. Instant treatment often results in faster reduction of inflammation and, as a consequence, less structural damage. Anatomical imaging techniques have been in use for a long time, facilitating diagnosis and monitoring of RA. However, mere imaging of anatomical structures provides little information on the processes preceding changes in synovial tissue, cartilage, and bone. Molecular imaging might facilitate more effective diagnosis and monitoring in addition to providing new information on the disease pathogenesis. A limiting factor in the development of new molecular imaging techniques is the availability of suitable probes. Here, we review which cells and molecules can be targeted in the RA joint and discuss the advances that have been made in imaging of arthritis with a focus on such molecular targets as folate receptor, F4/80, macrophage mannose receptor, E-selectin, intercellular adhesion molecule-1, phosphatidylserine, and matrix metalloproteinases. In addition, we discuss a new tool that is being introduced in the field, namely the use of nanobodies as tracers. Finally, we describe additional molecules displaying specific features in joint inflammation and propose these as potential new molecular imaging targets, more specifically receptor activator of nuclear factor ?B and its ligand, chemokine receptors, vascular cell adhesion molecule-1, ?V?3 integrin, P2X7 receptor, suppression of tumorigenicity 2, dendritic cell-specific transmembrane protein, and osteoclast-stimulatory transmembrane protein. PMID:25099015

  2. COAL AND CHAR STUDIES BY ADVANCED EMR TECHNIQUES

    SciTech Connect

    R. Linn Belford; Robert B. Clarkson; Mark J. Nilges; Boris M. Odintsov; Alex I. Smirnov

    2001-04-30

    Advanced electronic magnetic resonance (EMR) as well as nuclear magnetic resonance (NMR) methods have been used to examine properties of coals, chars, and molecular species related to constituents of coal. During the span of this grant, progress was made on construction and applications to coals and chars of two high frequency EMR systems particularly appropriate for such studies--48 GHz and 95 GHz electron magnetic resonance spectrometer, on new low-frequency dynamic nuclear polarization (DNP) experiments to examine the interaction between water and the surfaces of suspended char particulates in slurries, and on a variety of proton nuclear magnetic resonance (NMR) techniques to measure characteristics of the water directly in contact with the surfaces and pore spaces of carbonaceous particulates.

  3. Automatic Molecular Design using Evolutionary Techniques

    NASA Technical Reports Server (NTRS)

    Globus, Al; Lawton, John; Wipke, Todd; Saini, Subhash (Technical Monitor)

    1998-01-01

    Molecular nanotechnology is the precise, three-dimensional control of materials and devices at the atomic scale. An important part of nanotechnology is the design of molecules for specific purposes. This paper describes early results using genetic software techniques to automatically design molecules under the control of a fitness function. The fitness function must be capable of determining which of two arbitrary molecules is better for a specific task. The software begins by generating a population of random molecules. The population is then evolved towards greater fitness by randomly combining parts of the better individuals to create new molecules. These new molecules then replace some of the worst molecules in the population. The unique aspect of our approach is that we apply genetic crossover to molecules represented by graphs, i.e., sets of atoms and the bonds that connect them. We present evidence suggesting that crossover alone, operating on graphs, can evolve any possible molecule given an appropriate fitness function and a population containing both rings and chains. Prior work evolved strings or trees that were subsequently processed to generate molecular graphs. In principle, genetic graph software should be able to evolve other graph representable systems such as circuits, transportation networks, metabolic pathways, computer networks, etc.

  4. Bringing Advanced Computational Techniques to Energy Research

    SciTech Connect

    Mitchell, Julie C

    2012-11-17

    Please find attached our final technical report for the BACTER Institute award. BACTER was created as a graduate and postdoctoral training program for the advancement of computational biology applied to questions of relevance to bioenergy research.

  5. 78 FR 59927 - Next Generation Risk Assessment: Incorporation of Recent Advances in Molecular, Computational...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-30

    ...Recent Advances in Molecular, Computational, and Systems Biology [External Review...Recent Advances in Molecular, Computational, and Systems Biology [External Review...Recent Advances in Molecular, Computational, and Systems Biology [External...

  6. Recent Advances in Molecular Magnetic Resonance Imaging of Liver Fibrosis

    PubMed Central

    Li, Zhiming; Sun, Jihong; Yang, Xiaoming

    2015-01-01

    Liver fibrosis is a life-threatening disease with high morbidity and mortality owing to its diverse causes. Liver biopsy, as the current gold standard for diagnosing and staging liver fibrosis, has a number of limitations, including sample variability, relatively high cost, an invasive nature, and the potential of complications. Most importantly, in clinical practice, patients often reject additional liver biopsies after initiating treatment despite their being necessary for long-term follow-up. To resolve these problems, a number of different noninvasive imaging-based methods have been developed for accurate diagnosis of liver fibrosis. However, these techniques only reflect morphological or perfusion-related alterations in the liver, and thus they are generally only useful for the diagnosis of late-stage liver fibrosis (liver cirrhosis), which is already characterized by “irreversible” anatomic and hemodynamic changes. Thus, it is essential that new approaches are developed for accurately diagnosing early-stage liver fibrosis as at this stage the disease may be “reversed” by active treatment. The development of molecular MR imaging technology has potential in this regard, as it facilitates noninvasive, target-specific imaging of liver fibrosis. We provide an overview of recent advances in molecular MR imaging for the diagnosis and staging of liver fibrosis and we compare novel technologies with conventional MR imaging techniques. PMID:25874221

  7. Molecular Technique to Understand Deep Microbial Diversity

    NASA Technical Reports Server (NTRS)

    Vaishampayan, Parag A.; Venkateswaran, Kasthuri J.

    2012-01-01

    Current sequencing-based and DNA microarray techniques to study microbial diversity are based on an initial PCR (polymerase chain reaction) amplification step. However, a number of factors are known to bias PCR amplification and jeopardize the true representation of bacterial diversity. PCR amplification of the minor template appears to be suppressed by the exponential amplification of the more abundant template. It is widely acknowledged among environmental molecular microbiologists that genetic biosignatures identified from an environment only represent the most dominant populations. The technological bottleneck has overlooked the presence of the less abundant minority population, and underestimated their role in the ecosystem maintenance. To generate PCR amplicons for subsequent diversity analysis, bacterial l6S rRNA genes are amplified by PCR using universal primers. Two distinct PCR regimes are employed in parallel: one using normal and the other using biotinlabeled universal primers. PCR products obtained with biotin-labeled primers are mixed with streptavidin-labeled magnetic beads and selectively captured in the presence of a magnetic field. Less-abundant DNA templates that fail to amplify in this first round of PCR amplification are subjected to a second round of PCR using normal universal primers. These PCR products are then subjected to downstream diversity analyses such as conventional cloning and sequencing. A second round of PCR amplified the minority population and completed the deep diversity picture of the environmental sample.

  8. Advanced interference management techniques for future wireless networks 

    E-print Network

    Razavi, Seyed Morteza

    2014-06-30

    In this thesis, we design advanced interference management techniques for future wireless networks under the availability of perfect and imperfect channel state information (CSI). We do so by considering a generalized ...

  9. Advances in molecular breeding of flowering dogwood (Cornus florida L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although the production and sales of ornamental crops represent significant contributions to the global economy, breeding and selection of ornamental plants using molecular markers lags far behind that used for agronomic crops. However, with the recent advances in molecular technologies including r...

  10. Molecular Genetics Techniques to Develop New Treatments for Brain Cancers

    SciTech Connect

    Fox, Jacob; Fathallan-Shaykh, Hassan

    2006-09-22

    The objectives of this report are: (1) to devise novel molecular gene therapies for malignant brain tumors, (2) advance our understanding of the immune system in the central nervous system; and (3) apply genomics to find molecular probes to diagnose brain tumors, predict prognosis, biological behavior and their response to treatment.

  11. Recent advances in DNA sequencing techniques

    NASA Astrophysics Data System (ADS)

    Singh, Rama Shankar

    2013-06-01

    Successful mapping of the draft human genome in 2001 and more recent mapping of the human microbiome genome in 2012 have relied heavily on the parallel processing of the second generation/Next Generation Sequencing (NGS) DNA machines at a cost of several millions dollars and long computer processing times. These have been mainly biochemical approaches. Here a system analysis approach is used to review these techniques by identifying the requirements, specifications, test methods, error estimates, repeatability, reliability and trends in the cost reduction. The first generation, NGS and the Third Generation Single Molecule Real Time (SMART) detection sequencing methods are reviewed. Based on the National Human Genome Research Institute (NHGRI) data, the achieved cost reduction of 1.5 times per yr. from Sep. 2001 to July 2007; 7 times per yr., from Oct. 2007 to Apr. 2010; and 2.5 times per yr. from July 2010 to Jan 2012 are discussed.

  12. Molecular biology techniques and applications for ocean sensing

    NASA Astrophysics Data System (ADS)

    Zehr, J. P.; Hewson, I.; Moisander, P. H.

    2008-11-01

    The study of marine microorganisms using molecular biological techniques is now widespread in the ocean sciences. These techniques target nucleic acids which record the evolutionary history of microbes, and encode for processes which are active in the ocean today. Here we review some of the most commonly used molecular biological techniques. Molecular biological techniques permit study of the abundance, distribution, diversity, and physiology of microorganisms in situ. These techniques include the polymerase chain reaction (PCR) and reverse-transcriptase PCR, quantitative PCR, whole assemblage "fingerprinting" approaches (based on nucleic acid sequence or length heterogeneity), oligonucleotide microarrays, and high-throughput shotgun sequencing of whole genomes and gene transcripts, which can be used to answer biological, ecological, evolutionary and biogeochemical questions in the ocean sciences. Moreover, molecular biological approaches may be deployed on ocean sensor platforms and hold promise for tracking of organisms or processes of interest in near-real time.

  13. Molecular techniques to interrogate and edit the Chlamydomonas nuclear genome.

    PubMed

    Jinkerson, Robert E; Jonikas, Martin C

    2015-05-01

    The success of the green alga Chlamydomonas reinhardtii as a model organism is to a large extent due to the wide range of molecular techniques that are available for its characterization. Here, we review some of the techniques currently used to modify and interrogate the C. reinhardtii nuclear genome and explore several technologies under development. Nuclear mutants can be generated with ultraviolet (UV) light and chemical mutagens, or by insertional mutagenesis. Nuclear transformation methods include biolistic delivery, agitation with glass beads, and electroporation. Transforming DNA integrates into the genome at random sites, and multiple strategies exist for mapping insertion sites. A limited number of studies have demonstrated targeted modification of the nuclear genome by approaches such as zinc-finger nucleases and homologous recombination. RNA interference is widely used to knock down expression levels of nuclear genes. A wide assortment of transgenes has been successfully expressed in the Chlamydomonas nuclear genome, including transformation markers, fluorescent proteins, reporter genes, epitope tagged proteins, and even therapeutic proteins. Optimized expression constructs and strains help transgene expression. Emerging technologies such as the CRISPR/Cas9 system, high-throughput mutant identification, and a whole-genome knockout library are being developed for this organism. We discuss how these advances will propel future investigations. PMID:25704665

  14. 78 FR 68058 - Next Generation Risk Assessment: Incorporation of Recent Advances in Molecular, Computational...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-13

    ...Recent Advances in Molecular, Computational, and Systems Biology [External Review...Recent Advances in Molecular, Computational, and Systems Biology [External Review...explores how new molecular, computational, and systems biology data can...

  15. Innovative Tools Advance Revolutionary Weld Technique

    NASA Technical Reports Server (NTRS)

    2009-01-01

    The iconic, orange external tank of the space shuttle launch system not only contains the fuel used by the shuttle s main engines during liftoff but also comprises the shuttle s backbone, supporting the space shuttle orbiter and solid rocket boosters. Given the tank s structural importance and the extreme forces (7.8 million pounds of thrust load) and temperatures it encounters during launch, the welds used to construct the tank must be highly reliable. Variable polarity plasma arc welding, developed for manufacturing the external tank and later employed for building the International Space Station, was until 1994 the best process for joining the aluminum alloys used during construction. That year, Marshall Space Flight Center engineers began experimenting with a relatively new welding technique called friction stir welding (FSW), developed in 1991 by The Welding Institute, of Cambridge, England. FSW differs from traditional fusion welding in that it is a solid-state welding technique, using frictional heat and motion to join structural components without actually melting any of the material. The weld is created by a shouldered pin tool that is plunged into the seam of the materials to be joined. The tool traverses the line while rotating at high speeds, generating friction that heats and softens but does not melt the metal. (The heat produced approaches about 80 percent of the metal s melting temperature.) The pin tool s rotation crushes and stirs the plasticized metal, extruding it along the seam as the tool moves forward. The material cools and consolidates, resulting in a weld with superior mechanical properties as compared to those weld properties of fusion welds. The innovative FSW technology promises a number of attractive benefits. Because the welded materials are not melted, many of the undesirables associated with fusion welding porosity, cracking, shrinkage, and distortion of the weld are minimized or avoided. The process is more energy efficient, safe (no toxic smoke or shielding gas, liquid metal splatter, arcing, dangerous voltage, or radiation), and environmentally sound (no consumables, fumes, or noise) than fusion welding. Under computer control, an automated FSW machine can create welds with high reproducibility, improving efficiency and overall quality of manufactured materials. The process also allows for welding dissimilar metals as well as those metals considered to be "unweldable" such as the 7xxx series aluminum alloys. Its effectiveness and versatility makes FSW useful for aerospace, rail, automotive, marine, and military applications. A downside to FSW, however, is the keyhole opening left in the weld when the FSW pin tool exits the weld joint. This is a significant problem when using the FSW process to join circumferential structures such as pipes and storage containers. Furthermore, weld joints that taper in material thickness also present problems when using the conventional FSW pin tool, because the threaded pin rotating within the weld joint material is a fixed length. There must be capability for the rotating pin to both increase and decrease in length in real time while welding the tapered material. (Both circumferential and tapered thickness weldments are found in the space shuttle external tank.) Marshall engineers addressed both the keyhole and tapered material thickness problems by developing the auto-adjustable pin tool. This unique piece of equipment automatically withdraws the pin into the tool s shoulder for keyhole closeout. In addition, the auto-adjustable pin tool retracts, or shortens, the rotating pin while welding a weld joint that tapers from one thickness to a thinner thickness. This year, the impact of the Marshall innovation was recognized with an "Excellence in Technology Transfer Award" from the Federal Laboratory Consortium.

  16. Advances in gamma titanium aluminides and their manufacturing techniques

    NASA Astrophysics Data System (ADS)

    Kothari, Kunal; Radhakrishnan, Ramachandran; Wereley, Norman M.

    2012-11-01

    Gamma titanium aluminides display attractive properties for high temperature applications. For over a decade in the 1990s, the attractive properties of titanium aluminides were outweighed by difficulties encountered in processing and machining at room temperature. But advances in manufacturing technologies, deeper understanding of titanium aluminides microstructure, deformation mechanisms, and advances in micro-alloying, has led to the production of gamma titanium aluminide sheets. An in-depth review of key advances in gamma titanium aluminides is presented, including microstructure, deformation mechanisms, and alloy development. Traditional manufacturing techniques such as ingot metallurgy and investment casting are reviewed and advances via powder metallurgy based manufacturing techniques are discussed. Finally, manufacturing challenges facing gamma titanium aluminides, as well as avenues to overcome them, are discussed.

  17. Teaching Molecular Biological Techniques in a Research Content

    ERIC Educational Resources Information Center

    Stiller, John W.; Coggins, T. Chad

    2006-01-01

    Molecular biological methods, such as the polymerase chain reaction (PCR) and gel electrophoresis, are now commonly taught to students in introductory biology courses at the college and even high school levels. This often includes hands-on experience with one or more molecular techniques as part of a general biology laboratory. To assure that most…

  18. Pathology and Molecular Genetics of Meningioma: Recent Advances

    PubMed Central

    SHIBUYA, Makoto

    2015-01-01

    Meningiomas are the most common intracranial primary neoplasm in adults. Although the spectrum of clinical and molecular genetic issues regarding meningiomas remains undefined, novel genetic alterations that are associated with tumor morphology, malignancy, or location have recently been discovered. This review focuses on recent advances in understanding of the heterogenous pathology of meningiomas, particularly on associations between the clinical, histological, etiological, epidemiological, and molecular genetical aspects of the neoplasm. PMID:25744347

  19. Rhabdomyosarcoma: Advances in Molecular and Cellular Biology

    PubMed Central

    Sun, Xin; Guo, Wei; Shen, Jacson K.; Mankin, Henry J.; Hornicek, Francis J.; Duan, Zhenfeng

    2015-01-01

    Rhabdomyosarcoma (RMS) is the most common soft tissue malignancy in childhood and adolescence. The two major histological subtypes of RMS are alveolar RMS, driven by the fusion protein PAX3-FKHR or PAX7-FKHR, and embryonic RMS, which is usually genetically heterogeneous. The prognosis of RMS has improved in the past several decades due to multidisciplinary care. However, in recent years, the treatment of patients with metastatic or refractory RMS has reached a plateau. Thus, to improve the survival rate of RMS patients and their overall well-being, further understanding of the molecular and cellular biology of RMS and identification of novel therapeutic targets are imperative. In this review, we describe the most recent discoveries in the molecular and cellular biology of RMS, including alterations in oncogenic pathways, miRNA (miR), in vivo models, stem cells, and important signal transduction cascades implicated in the development and progression of RMS. Furthermore, we discuss novel potential targeted therapies that may improve the current treatment of RMS. PMID:26420980

  20. Rhabdomyosarcoma: Advances in Molecular and Cellular Biology.

    PubMed

    Sun, Xin; Guo, Wei; Shen, Jacson K; Mankin, Henry J; Hornicek, Francis J; Duan, Zhenfeng

    2015-01-01

    Rhabdomyosarcoma (RMS) is the most common soft tissue malignancy in childhood and adolescence. The two major histological subtypes of RMS are alveolar RMS, driven by the fusion protein PAX3-FKHR or PAX7-FKHR, and embryonic RMS, which is usually genetically heterogeneous. The prognosis of RMS has improved in the past several decades due to multidisciplinary care. However, in recent years, the treatment of patients with metastatic or refractory RMS has reached a plateau. Thus, to improve the survival rate of RMS patients and their overall well-being, further understanding of the molecular and cellular biology of RMS and identification of novel therapeutic targets are imperative. In this review, we describe the most recent discoveries in the molecular and cellular biology of RMS, including alterations in oncogenic pathways, miRNA (miR), in vivo models, stem cells, and important signal transduction cascades implicated in the development and progression of RMS. Furthermore, we discuss novel potential targeted therapies that may improve the current treatment of RMS. PMID:26420980

  1. Advances in understanding angiogenesis through molecular studies

    SciTech Connect

    Kwon, Mijung; Libutti, Steven K. . E-mail: steven_libutti@nih.gov

    2006-01-01

    Tumors, in most cases, need angiogenesis for their sustained growth. A great deal of evidence has suggested that the process of angiogenesis is regulated by the balance between proangiogenic and antiangiogenic factors. Thus, the inhibition of tumor angiogenesis has been considered to be one of the key targets in anticancer therapy, and more than 60 antiangiogenic compounds are currently under clinical evaluation in cancer patients. However, the molecular mechanisms responsible for the activity of many of these antiangiogenic compounds are still not well understood. The recent development of microarray technology has allowed us to investigate the mechanism of action of these inhibitors more rapidly and extensively. With the use of microarray technology, novel molecules and pathways are shown to play a role in angiogenesis. This article also reviews new experimental approaches combined with microarray analysis to identify the molecular pathways involved in tumor-host interactions. Elucidation of the pathways that mediate both angiogenic and antiangiogenic responses will help us to develop better anticancer therapies.

  2. Airborne myxomycete spores: detection using molecular techniques

    NASA Astrophysics Data System (ADS)

    Kamono, Akiko; Kojima, Hisaya; Matsumoto, Jun; Kawamura, Kimitaka; Fukui, Manabu

    2009-01-01

    Myxomycetes are organisms characterized by a life cycle that includes a fruiting body stage. Myxomycete fruiting bodies contain spores, and wind dispersal of the spores is considered important for this organism to colonize new areas. In this study, the presence of airborne myxomycetes and the temporal changes in the myxomycete composition of atmospheric particles (aerosols) were investigated with a polymerase chain reaction (PCR)-based method for Didymiaceae and Physaraceae. Twenty-one aerosol samples were collected on the roof of a three-story building located in Sapporo, Hokkaido Island, northern Japan. PCR analysis of DNA extracts from the aerosol samples indicated the presence of airborne myxomycetes in all the samples, except for the one collected during the snowfall season. Denaturing gradient gel electrophoresis (DGGE) analysis of the PCR products showed seasonally varying banding patterns. The detected DGGE bands were subjected to sequence analyses, and four out of nine obtained sequences were identical to those of fruiting body samples collected in Hokkaido Island. It appears that the difference in the fruiting period of each species was correlated with the seasonal changes in the myxomycete composition of the aerosols. Molecular evidence shows that newly formed spores are released and dispersed in the air, suggesting that wind-driven dispersal of spores is an important process in the life history of myxomycetes. This study is the first to detect airborne myxomycetes with the use of molecular ecological analyses and to characterize their seasonal distribution.

  3. Coal and char studies by advanced EMR techniques

    SciTech Connect

    Belford, R.L.; Clarkson, R.B.; Odintsov, B.M.

    1998-09-30

    Advanced magnetic resonance (EMR) methods are used to examine properties of coals, chars, and molecular species related to constituents of coal. During this grant period, further progress was made on proton NMR and low-frequency dynamic nuclear polarization (DNP) to examine the interaction between fluids such as water and the surface of suspended char particles. Effects of char particle size on water nuclear spin relaxation, T2, were measured.

  4. Coal and Coal Constituent Studies by Advanced EMR Techniques.

    SciTech Connect

    Belford, R.L.; Clarkson, R.B.; Odintsov, B.; Ceroke, P.J.

    1997-09-30

    Advanced electronic magnetic resonance (EMR) methods are used to examine properties of coals, chars, and molecular species related to constituents of coal. During this grant period, progress was made on a high frequency EMR system particularly appropriate for such studies and on low-frequency dynamic nuclear polarization (DNP) to examine the interaction between fluids such as water and the surface of suspended char particles.

  5. Advances in molecular genetic systems in malaria.

    PubMed

    de Koning-Ward, Tania F; Gilson, Paul R; Crabb, Brendan S

    2015-06-01

    Robust tools for analysing gene function in Plasmodium parasites, which are the causative agents of malaria, are being developed at an accelerating rate. Two decades after genetic technologies for use in Plasmodium spp. were first described, a range of genetic tools are now available. These include conditional systems that can regulate gene expression at the genome, transcriptional or protein level, as well as more sophisticated tools for gene editing that use piggyBac transposases, integrases, zinc-finger nucleases or the CRISPR-Cas9 system. In this Review, we discuss the molecular genetic systems that are currently available for use in Plasmodium falciparum and Plasmodium berghei, and evaluate the advantages and limitations of these tools. We examine the insights that have been gained into the function of genes that are important during the blood stages of the parasites, which may help to guide the development and improvement of drug therapies and vaccines. PMID:25978707

  6. Advanced alloy design technique: High temperature cobalt base superalloy

    NASA Technical Reports Server (NTRS)

    Dreshfield, R. L.; Freche, J. C.; Sandrock, G. D.

    1972-01-01

    Advanced alloy design technique was developed for treating alloys that will have extended life in service at high temperature and intermediate temperatures. Process stabilizes microstructure of the alloy by designing it so that compound identified with embrittlement is eliminated or minimized. Design process is being used to develop both nickel and cobalt-base superalloys.

  7. Towards Optimal Circuit Layout Using Advanced Search Techniques

    E-print Network

    Areibi, Shawki M

    Towards Optimal Circuit Layout Using Advanced Search Techniques by Shawki Areibi A thesis presented be computationally fast but also generate layouts close to optimal. The work in this thesis involves exploring algorithmic solutions to the problem of circuit layout in VLSI design. The exploration is an attempt

  8. Recent advances in understanding the molecular basis of group B

    E-print Network

    Nizet, Victor

    a leading cause of neonatal pneumonia, sepsis and meningitis. Here we review recent informationRecent advances in understanding the molecular basis of group B Streptococcus virulence Heather C. Maisey1 , Kelly S. Doran2 and Victor Nizet1,3, * Group B Streptococcus commonly colonises healthy adults

  9. Responses of Cell Renewal Systems to Long-term Low-Level Radiation Exposure: A Feasibility Study Applying Advanced Molecular Biology Techniques on Available Histological and Cytological Material of Exposed Animals and Men

    SciTech Connect

    Fliedner Theodor M.; Feinendegen Ludwig E.; Meineke Viktor; Fritz Thomas E.

    2005-02-28

    First results of this feasibility study showed that evaluation of the stored material of the chronically irradiated dogs with modern molecular biological techniques proved to be successful and extremely promising. Therefore an in deep analysis of at least part of the huge amount of remaining material is of outmost interest. The methods applied in this feasibility study were pathological evaluation with different staining methods, protein analysis by means of immunohistochemistry, strand break analysis with the TdT-assay, DNA- and RNA-analysis as well as genomic examination by gene array. Overall more than 50% of the investigated material could be used. In particular the results of an increased stimulation of the immune system within the dogs of the 3mSv group as both compared to the control and higher dose groups gives implications for the in depth study of the cellular events occurring in context with low dose radiation. Based on the findings of this study a further evaluation and statistically analysis of more material can help to identify promising biomarkers for low dose radiation. A systematic evaluation of a correlation of dose rates and strand breaks within the dog tissue might moreover help to explain mechanisms of tolerance to IR. One central problem is that most sequences for dog specific primers are not known yet. The discovery of the dog genome is still under progress. In this study the isolation of RNA within the dog tissue was successful. But up to now there are no gene arrays or gene chips commercially available, tested and adapted for canine tissue. The uncritical use of untested genomic test systems for canine tissue seems to be ineffective at the moment, time consuming and ineffective. Next steps in the investigation of genomic changes after IR within the stored dog tissue should be limited to quantitative RT-PCR of tested primer sequences for the dog. A collaboration with institutions working in the field of the discovery of the dog genome could have synergistic effects.

  10. Advanced fault diagnosis methods in molecular networks.

    PubMed

    Habibi, Iman; Emamian, Effat S; Abdi, Ali

    2014-01-01

    Analysis of the failure of cell signaling networks is an important topic in systems biology and has applications in target discovery and drug development. In this paper, some advanced methods for fault diagnosis in signaling networks are developed and then applied to a caspase network and an SHP2 network. The goal is to understand how, and to what extent, the dysfunction of molecules in a network contributes to the failure of the entire network. Network dysfunction (failure) is defined as failure to produce the expected outputs in response to the input signals. Vulnerability level of a molecule is defined as the probability of the network failure, when the molecule is dysfunctional. In this study, a method to calculate the vulnerability level of single molecules for different combinations of input signals is developed. Furthermore, a more complex yet biologically meaningful method for calculating the multi-fault vulnerability levels is suggested, in which two or more molecules are simultaneously dysfunctional. Finally, a method is developed for fault diagnosis of networks based on a ternary logic model, which considers three activity levels for a molecule instead of the previously published binary logic model, and provides equations for the vulnerabilities of molecules in a ternary framework. Multi-fault analysis shows that the pairs of molecules with high vulnerability typically include a highly vulnerable molecule identified by the single fault analysis. The ternary fault analysis for the caspase network shows that predictions obtained using the more complex ternary model are about the same as the predictions of the simpler binary approach. This study suggests that by increasing the number of activity levels the complexity of the model grows; however, the predictive power of the ternary model does not appear to be increased proportionally. PMID:25290670

  11. Advanced Packaging Materials and Techniques for High Power TR Module: Standard Flight vs. Advanced Packaging

    NASA Technical Reports Server (NTRS)

    Hoffman, James Patrick; Del Castillo, Linda; Miller, Jennifer; Jenabi, Masud; Hunter, Donald; Birur, Gajanana

    2011-01-01

    The higher output power densities required of modern radar architectures, such as the proposed DESDynI [Deformation, Ecosystem Structure, and Dynamics of Ice] SAR [Synthetic Aperture Radar] Instrument (or DSI) require increasingly dense high power electronics. To enable these higher power densities, while maintaining or even improving hardware reliability, requires advances in integrating advanced thermal packaging technologies into radar transmit/receive (TR) modules. New materials and techniques have been studied and compared to standard technologies.

  12. Organic conductors as novel ``molecular rulers`` for advanced manufacturing processes

    SciTech Connect

    Williams, J.M.

    1995-12-31

    Future advanced manufacturing equipment used in high technology programs will require ultra-high precision and associated machining tool operations that require placement accuracy of {approximately} 1--100 nm (1 nm = 10 {angstrom}). There is consensus among engineers that this equipment will be based on STM (Scanning Tunneling Microscope) technology. All such STM-based ``drivers`` must contain a metrology system that requires absolute length standards referenced to atomic spacings for calibration. Properly designed organic conductor substrate crystals have the potential to be molecular rulers for STM-based advanced manufacturing equipment. The major challenges in future organic conductor research aimed at STM metrology application are listed.

  13. Technology development of fabrication techniques for advanced solar dynamic concentrators

    NASA Technical Reports Server (NTRS)

    Richter, Scott W.

    1991-01-01

    The objective of the advanced concentrator program is to develop the technology that will lead to lightweight, highly reflective, accurate, scaleable, and long lived space solar dynamic concentrators. The advanced concentrator program encompasses new and innovative concepts, fabrication techniques, materials selection, and simulated space environmental testing. Fabrication techniques include methods of fabricating the substrates and coating substrate surfaces to produce high quality optical surfaces, acceptable for further coating with vapor deposited optical films. The selected materials to obtain a high quality optical surface include microsheet glass and Eccocoat EP-3 epoxy, with DC-93-500 selected as a candidate silicone adhesive and levelizing layer. The following procedures are defined: cutting, cleaning, forming, and bonding microsheet glass. Procedures are also defined for surface cleaning, and EP-3 epoxy application. The results and analyses from atomic oxygen and thermal cycling tests are used to determine the effects of orbital conditions in a space environment.

  14. Technology development of fabrication techniques for advanced solar dynamic concentrators

    NASA Technical Reports Server (NTRS)

    Richter, Scott W.

    1991-01-01

    The objective of the advanced concentrator program is to develop the technology that will lead to lightweight, highly reflective, accurate, scaleable, and long lived space solar dynamic concentrators. The advanced concentrator program encompasses new and innovative concepts, fabrication techniques, materials selection, and simulated space environmental testing. Fabrication techniques include methods of fabricating the substrates and coating substrate surfaces to produce high-quality optical surfaces, acceptable for further coating with vapor deposited optical films. The selected materials to obtain a high quality optical surface include microsheet glass and Eccocoat EP-3 epoxy, with DC-93-500 selected as a candidate silicone adhesive and levelizing layer. The following procedures are defined: cutting, cleaning, forming, and bonding microsheet glass. Procedures are also defined for surface cleaning, and EP-3 epoxy application. The results and analyses from atomic oxygen and thermal cycling tests are used to determine the effects of orbital conditions in a space environment.

  15. The Advanced Space Plant Culture Device with Live Imaging Technique

    NASA Astrophysics Data System (ADS)

    Zheng, Weibo; Zhang, Tao; Tong, Guanghui

    The live imaging techniques, including the color and fluorescent imags, are very important and useful for space life science. The advanced space plant culture Device (ASPCD) with live imaging Technique, developed for Chinese Spacecraft, would be introduced in this paper. The ASPCD had two plant experimental chambers. Three cameras (two color cameras and one fluorescent camera) were installed in the two chambers. The fluorescent camera could observe flowering genes, which were labeled by GFP. The lighting, nutrient, temperature controling and water recycling were all independent in each chamber. The ASPCD would beed applied to investigate for the growth and development of the high plant under microgravity conditions on board the Chinese Spacecraft.

  16. Advances in Computational Techniques to Study GPCR-Ligand Recognition.

    PubMed

    Ciancetta, Antonella; Sabbadin, Davide; Federico, Stephanie; Spalluto, Giampiero; Moro, Stefano

    2015-12-01

    G-protein-coupled receptors (GPCRs) are among the most intensely investigated drug targets. The recent revolutions in protein engineering and molecular modeling algorithms have overturned the research paradigm in the GPCR field. While the numerous ligand-bound X-ray structures determined have provided invaluable insights into GPCR structure and function, the development of algorithms exploiting graphics processing units (GPUs) has made the simulation of GPCRs in explicit lipid-water environments feasible within reasonable computation times. In this review we present a survey of the recent advances in structure-based drug design approaches with a particular emphasis on the elucidation of the ligand recognition process in class A GPCRs by means of membrane molecular dynamics (MD) simulations. PMID:26538318

  17. Three-dimensional hybrid grid generation using advancing front techniques

    NASA Technical Reports Server (NTRS)

    Steinbrenner, John P.; Noack, Ralph W.

    1995-01-01

    A new 3-dimensional hybrid grid generation technique has been developed, based on ideas of advancing fronts for both structured and unstructured grids. In this approach, structured grids are first generate independently around individual components of the geometry. Fronts are initialized on these structure grids, and advanced outward so that new cells are extracted directly from the structured grids. Employing typical advancing front techniques, cells are rejected if they intersect the existing front or fail other criteria When no more viable structured cells exist further cells are advanced in an unstructured manner to close off the overall domain, resulting in a grid of 'hybrid' form. There are two primary advantages to the hybrid formulation. First, generating blocks with limited regard to topology eliminates the bottleneck encountered when a multiple block system is used to fully encapsulate a domain. Individual blocks may be generated free of external constraints, which will significantly reduce the generation time. Secondly, grid points near the body (presumably with high aspect ratio) will still maintain a structured (non-triangular or tetrahedral) character, thereby maximizing grid quality and solution accuracy near the surface.

  18. On The Use of Molecular Filter Based Techniques

    NASA Astrophysics Data System (ADS)

    Elliott, Greg; Glumac, Nick; Carter, Campbell

    1998-11-01

    Techniques employing molecular filters have been introduced in a variety of flow diagnostic techniques by various research groups. The molecular filter is a cylindrical optical cell which contains a molecule with absorption lines within the frequency of the laser interrogating the flow field. The molecular filter is placed in front of the receiving optics to modify the recorded intensity based on the frequency of the scattered light. There are three techniques which are currently being developed at Rutgers University. The first is termed Planar Doppler Velocimetry (PDV) which can measure multiple velocity components in a plane. This technique has been used in small laboratory facilities, as well as applied to measure the velocity field around models tested in large wind tunnels with an accuracy better than 2 m/s. A second technique termed Filtered Rayleigh scattering (FRS) has been extended to measure the instantaneous two-dimensional temperature in combustion environments. FRS has the advantage over typical Rayleigh scattering since measurements can be made close to surfaces (within 10um) and in flames dominated by solid particles. FRS temperature measurements in a hydrogen/air flame were compared to CARS measurements suggesting that an accuracy better than 3% can be achieved. The third technique, termed Filtered Angularly Resolved Rayleigh Scattering (FARRS), allows the simultaneous measurement of instantaneous pressure, density, temperature, and velocity fluctuations. FARRS measurements of turbulence quantities in subsonic and supersonic jets have been conducted and the correlation between various quantities are currently being computed.

  19. MOLECULAR OPTICAL SPECTROSCOPIC TECHNIQUES FOR HAZARDOUS WASTE SITE SCREENING

    EPA Science Inventory

    The U.S. Environmental Protection Agency is interested in field screening hazardous waste sites for contaminants in the soil and surface and ground water. his study is an initial technical overview of the principal molecular spectroscopic techniques and instrumentation currently ...

  20. Full Endoscopic Spinal Surgery Techniques: Advancements, Indications, and Outcomes.

    PubMed

    Yue, James J; Long, William

    2015-01-01

    Advancements in both surgical instrumentation and full endoscopic spine techniques have resulted in positive clinical outcomes in the treatment of cervical, thoracic, and lumbar spine pathologies. Endoscopic techniques impart minimal approach related disruption of non-pathologic spinal anatomy and function while concurrently maximizing functional visualization and correction of pathological tissues. An advanced understanding of the applicable functional neuroanatomy, in particular the neuroforamen, is essential for successful outcomes. Additionally, an understanding of the varying types of disc prolapse pathology in relation to the neuroforamen will result in more optimal surgical outcomes. Indications for lumbar endoscopic spine surgery include disc herniations, spinal stenosis, infections, medial branch rhizotomy, and interbody fusion. Limitations are based on both non spine and spine related findings. A high riding iliac wing, a more posteriorly located retroperitoneal cavity, an overly distal or proximally migrated herniated disc are all relative contra-indications to lumbar endoscopic spinal surgery techniques. Modifications in scope size and visual field of view angulation have enabled both anterior and posterior cervical decompression. Endoscopic burrs, electrocautery, and focused laser technology allow for the least invasive spinal surgical techniques in all age groups and across varying body habitus. Complications include among others, dural tears, dysesthsia, nerve injury, and infection. PMID:26114086

  1. Engineering molecular mechanics: an efficient static high temperature molecular simulation technique.

    PubMed

    Subramaniyan, Arun K; Sun, C T

    2008-07-16

    Inspired by the need for an efficient molecular simulation technique, we have developed engineering molecular mechanics (EMM) as an alternative molecular simulation technique to model high temperature (T>0 K) phenomena. EMM simulations are significantly more computationally efficient than conventional techniques such as molecular dynamics simulations. The advantage of EMM is achieved by converting the dynamic atomistic system at high temperature (T>0 K) into an equivalent static system. Fundamentals of the EMM methodology are derived using thermal expansion to modify the interatomic potential. Temperature dependent interatomic potentials are developed to account for the temperature effect. The efficiency of EMM simulations is demonstrated by simulating the temperature dependence of elastic constants of copper and nickel and the thermal stress developed in a confined copper system. PMID:21828740

  2. An Effective Technique for Endoscopic Resection of Advanced Stage Angiofibroma

    PubMed Central

    Mohammadi Ardehali, Mojtaba; Samimi, Seyyed Hadi; Bakhshaee, Mehdi

    2014-01-01

    Introduction: In recent years, the surgical management of angiofibroma has been greatly influenced by the use of endoscopic techniques. However, large tumors that extend into difficult anatomic sites present major challenges for management by either endoscopy or an open-surgery approach which needs new technique for the complete en block resection. Materials and Methods: In a prospective observational study we developed an endoscopic transnasal technique for the resection of angiofibroma via pushing and pulling the mass with 1/100000 soaked adrenalin tampons. Thirty two patients were treated using this endoscopic technique over 7 years. The mean follow-up period was 36 months. The main outcomes measured were tumor staging, average blood loss, complications, length of hospitalization, and residual and/or recurrence rate of the tumor. Results: According to the Radkowski staging, 23,5, and 4 patients were at stage IIC, IIIA, and IIIB, respectively. Twenty five patients were operated on exclusively via transnasal endoscopy while 7 patients were managed using endoscopy-assisted open-surgery techniques. Mean blood loss in patients was 1261± 893 cc. The recurrence rate was 21.88% (7 cases) at two years following surgery. Mean hospitalization time was 3.56 ± 0.6 days. Conclusion: Using this effective technique, endoscopic removal of more highly advanced angiofibroma is possible. Better visualization, less intraoperative blood loss, lower rates of complication and recurrence, and shorter hospitalization time are some of the advantages. PMID:24505571

  3. Genioglossus muscle advancement: A modification of the conventional technique.

    PubMed

    García Vega, José Ramón; de la Plata, María Mancha; Galindo, Néstor; Navarro, Miriam; Díez, Daniel; Láncara, Fernando

    2014-04-01

    Obstructive sleep apnoea syndrome (OSAS) is a pathophysiologic condition associated with fragmented sleep and arousals caused by nocturnal mechanical obstruction of the upper airway. This results in behavioural derangements, such as excessive daytime sleepiness and fatigue, and pathophysiologic derangements that cause morbidities and mortality including hypertension, arrhythmias, myocardial infarction, stroke and sudden death. The genioglossus advancement is a proven technique for the treatment of mild to moderate obstructive sleep apnoea syndrome by relieving airway obstruction at the hypopharyngeal level. In this article, we report a modification of the conventional genioglossus advancement described by Riley and Powell. The modification we describe replaces the bone segment at the mandibular basal bone rather than at the mid area of the symphysis. This means a linear movement that allows a greater advancement and avoids the rotation of the genioglossus muscle. Through this article we will describe the advantages of the surgical technique such as greater effectiveness, stability, more pleasing aesthetic outcome and the reduction of potential complications. PMID:23849847

  4. Advanced aeroservoelastic stabilization techniques for hypersonic flight vehicles

    NASA Technical Reports Server (NTRS)

    Chan, Samuel Y.; Cheng, Peter Y.; Myers, Thomas T.; Klyde, David H.; Magdaleno, Raymond E.; Mcruer, Duane T.

    1992-01-01

    Advanced high performance vehicles, including Single-Stage-To-Orbit (SSTO) hypersonic flight vehicles, that are statically unstable, require higher bandwidth flight control systems to compensate for the instability resulting in interactions between the flight control system, the engine/propulsion dynamics, and the low frequency structural modes. Military specifications, such as MIL-F-9490D and MIL-F-87242, tend to limit treatment of structural modes to conventional gain stabilization techniques. The conventional gain stabilization techniques, however, introduce low frequency effective time delays which can be troublesome from a flying qualities standpoint. These time delays can be alleviated by appropriate blending of gain and phase stabilization techniques (referred to as Hybrid Phase Stabilization or HPS) for the low frequency structural modes. The potential of using HPS for compensating structural mode interaction was previously explored. It was shown that effective time delay was significantly reduced with the use of HPS; however, the HPS design was seen to have greater residual response than a conventional gain stablized design. Additional work performed to advance and refine the HPS design procedure, to further develop residual response metrics as a basis for alternative structural stability specifications, and to develop strategies for validating HPS design and specification concepts in manned simulation is presented. Stabilization design sensitivity to structural uncertainties and aircraft-centered requirements are also assessed.

  5. Recent advances in the molecular diagnostics of gastric cancer

    PubMed Central

    Kanda, Mitsuro; Kodera, Yasuhiro

    2015-01-01

    Gastric cancer (GC) is the third most common cause of cancer-related death in the world, representing a major global health issue. Although the incidence of GC is declining, the outcomes for GC patients remain dismal because of the lack of effective biomarkers to detect early GC and predict both recurrence and chemosensitivity. Current tumor markers for GC, including serum carcinoembryonic antigen and carbohydrate antigen 19-9, are not ideal due to their relatively low sensitivity and specificity. Recent improvements in molecular techniques are better able to identify aberrant expression of GC-related molecules, including oncogenes, tumor suppressor genes, microRNAs and long non-coding RNAs, and DNA methylation, as novel molecular markers, although the molecular pathogenesis of GC is complicated by tumor heterogeneity. Detection of genetic and epigenetic alterations from gastric tissue or blood samples has diagnostic value in the management of GC. There are high expectations for molecular markers that can be used as new screening tools for early detection of GC as well as for patient stratification towards personalized treatment of GC through prediction of prognosis and drug-sensitivity. In this review, the studies of potential molecular biomarkers for GC that have been reported in the publicly available literature between 2012 and 2015 are reviewed and summarized, and certain highlighted papers are examined. PMID:26379391

  6. Advanced Techniques for Removal of Retrievable Inferior Vena Cava Filters

    SciTech Connect

    Iliescu, Bogdan; Haskal, Ziv J.

    2012-08-15

    Inferior vena cava (IVC) filters have proven valuable for the prevention of primary or recurrent pulmonary embolism in selected patients with or at high risk for venous thromboembolic disease. Their use has become commonplace, and the numbers implanted increase annually. During the last 3 years, in the United States, the percentage of annually placed optional filters, i.e., filters than can remain as permanent filters or potentially be retrieved, has consistently exceeded that of permanent filters. In parallel, the complications of long- or short-term filtration have become increasingly evident to physicians, regulatory agencies, and the public. Most filter removals are uneventful, with a high degree of success. When routine filter-retrieval techniques prove unsuccessful, progressively more advanced tools and skill sets must be used to enhance filter-retrieval success. These techniques should be used with caution to avoid damage to the filter or cava during IVC retrieval. This review describes the complex techniques for filter retrieval, including use of additional snares, guidewires, angioplasty balloons, and mechanical and thermal approaches as well as illustrates their specific application.

  7. Advanced Time-Resolved Fluorescence Microscopy Techniques for the Investigation of Peptide Self-Assembly

    NASA Astrophysics Data System (ADS)

    Anthony, Neil R.

    The ubiquitous cross beta sheet peptide motif is implicated in numerous neurodegenerative diseases while at the same time offers remarkable potential for constructing isomorphic high-performance bionanomaterials. Despite an emerging understanding of the complex folding landscape of cross beta structures in determining disease etiology and final structure, we lack knowledge of the critical initial stages of nucleation and growth. In this dissertation, I advance our understanding of these key stages in the cross-beta nucleation and growth pathways using cutting-edge microscopy techniques. In addition, I present a new combined time-resolved fluorescence analysis technique with the potential to advance our current understanding of subtle molecular level interactions that play a pivotal role in peptide self-assembly. Using the central nucleating core of Alzheimer's Amyloid-beta protein, Abeta(16 22), as a model system, utilizing electron, time-resolved, and non-linear microscopy, I capture the initial and transient nucleation stages of peptide assembly into the cross beta motif. In addition, I have characterized the nucleation pathway, from monomer to paracrystalline nanotubes in terms of morphology and fluorescence lifetime, corroborating the predicted desolvation process that occurs prior to cross-beta nucleation. Concurrently, I have identified unique heterogeneous cross beta domains contained within individual nanotube structures, which have potential bionanomaterials applications. Finally, I describe a combined fluorescence theory and analysis technique that dramatically increases the sensitivity of current time-resolved techniques. Together these studies demonstrate the potential for advanced microscopy techniques in the identification and characterization of the cross-beta folding pathway, which will further our understanding of both amyloidogenesis and bionanomaterials.

  8. Advanced Techniques for Power System Identification from Measured Data

    SciTech Connect

    Pierre, John W.; Wies, Richard; Trudnowski, Daniel

    2008-11-25

    Time-synchronized measurements provide rich information for estimating a power-system's electromechanical modal properties via advanced signal processing. This information is becoming critical for the improved operational reliability of interconnected grids. A given mode's properties are described by its frequency, damping, and shape. Modal frequencies and damping are useful indicators of power-system stress, usually declining with increased load or reduced grid capacity. Mode shape provides critical information for operational control actions. This project investigated many advanced techniques for power system identification from measured data focusing on mode frequency and damping ratio estimation. Investigators from the three universities coordinated their effort with Pacific Northwest National Laboratory (PNNL). Significant progress was made on developing appropriate techniques for system identification with confidence intervals and testing those techniques on field measured data and through simulation. Experimental data from the western area power system was provided by PNNL and Bonneville Power Administration (BPA) for both ambient conditions and for signal injection tests. Three large-scale tests were conducted for the western area in 2005 and 2006. Measured field PMU (Phasor Measurement Unit) data was provided to the three universities. A 19-machine simulation model was enhanced for testing the system identification algorithms. Extensive simulations were run with this model to test the performance of the algorithms. University of Wyoming researchers participated in four primary activities: (1) Block and adaptive processing techniques for mode estimation from ambient signals and probing signals, (2) confidence interval estimation, (3) probing signal design and injection method analysis, and (4) performance assessment and validation from simulated and field measured data. Subspace based methods have been use to improve previous results from block processing techniques. Bootstrap techniques have been developed to estimate confidence intervals for the electromechanical modes from field measured data. Results were obtained using injected signal data provided by BPA. A new probing signal was designed that puts more strength into the signal for a given maximum peak to peak swing. Further simulations were conducted on a model based on measured data and with the modifications of the 19-machine simulation model. Montana Tech researchers participated in two primary activities: (1) continued development of the 19-machine simulation test system to include a DC line; and (2) extensive simulation analysis of the various system identification algorithms and bootstrap techniques using the 19 machine model. Researchers at the University of Alaska-Fairbanks focused on the development and testing of adaptive filter algorithms for mode estimation using data generated from simulation models and on data provided in collaboration with BPA and PNNL. There efforts consist of pre-processing field data, testing and refining adaptive filter techniques (specifically the Least Mean Squares (LMS), the Adaptive Step-size LMS (ASLMS), and Error Tracking (ET) algorithms). They also improved convergence of the adaptive algorithms by using an initial estimate from block processing AR method to initialize the weight vector for LMS. Extensive testing was performed on simulated data from the 19 machine model. This project was also extensively involved in the WECC (Western Electricity Coordinating Council) system wide tests carried out in 2005 and 2006. These tests involved injecting known probing signals into the western power grid. One of the primary goals of these tests was the reliable estimation of electromechanical mode properties from measured PMU data. Applied to the system were three types of probing inputs: (1) activation of the Chief Joseph Dynamic Brake, (2) mid-level probing at the Pacific DC Intertie (PDCI), and (3) low-level probing on the PDCI. The Chief Joseph Dynamic Brake is a 1400 MW disturbance to the system and is injected for a ha

  9. CD52 is a molecular target in advanced systemic mastocytosis.

    PubMed

    Hoermann, Gregor; Blatt, Katharina; Greiner, Georg; Putz, Eva Maria; Berger, Angelika; Herrmann, Harald; Cerny-Reiterer, Sabine; Gleixner, Karoline V; Walz, Christoph; Hoetzenecker, Konrad; Müllauer, Leonhard; Reiter, Andreas; Sotlar, Karl; Sexl, Veronika; Valent, Peter; Mayerhofer, Matthias

    2014-08-01

    Advanced systemic mastocytosis (SM) is an aggressive hematopoietic neoplasm with poor prognosis and short survival times. So far, no curative therapy is available for affected patients. We have identified the cell surface antigen CD52 (CAMPATH-1) as a molecular target expressed abundantly on the surface of primary neoplastic mast cells (MCs) in patients with advanced SM. In contrast, neoplastic MCs of patients with indolent SM and normal MCs expressed only low levels or did not express CD52. To study the mechanisms of CD52 expression and the value of this antigen as a potential therapeutic target, we generated a human MC cell line, designated MCPV-1, by lentiviral immortalization of cord blood-derived MC progenitor cells. Functional studies revealed that activated RAS profoundly promotes surface expression of CD52. The CD52-targeting antibody alemtuzumab induced cell death in CD52(+) primary neoplastic MCs obtained from patients with SM as well as in MCPV-1 cells. NSG mice xenotransplanted with MCPV-1 cells survived significantly longer after treatment with alemtuzumab (median survival: 31 d untreated vs. 46 d treated; P=0.0012). We conclude that CD52 is a novel marker and potential therapeutic target in neoplastic MCs in patients with advanced SM. PMID:24760752

  10. Techniques for developing approximate optimal advanced launch system guidance

    NASA Technical Reports Server (NTRS)

    Feeley, Timothy S.; Speyer, Jason L.

    1991-01-01

    An extension to the authors' previous technique used to develop a real-time guidance scheme for the Advanced Launch System is presented. The approach is to construct an optimal guidance law based upon an asymptotic expansion associated with small physical parameters, epsilon. The trajectory of a rocket modeled as a point mass is considered with the flight restricted to an equatorial plane while reaching an orbital altitude at orbital injection speeds. The dynamics of this problem can be separated into primary effects due to thrust and gravitational forces, and perturbation effects which include the aerodynamic forces and the remaining inertial forces. An analytic solution to the reduced-order problem represented by the primary dynamics is possible. The Hamilton-Jacobi-Bellman or dynamic programming equation is expanded in an asymptotic series where the zeroth-order term (epsilon = 0) can be obtained in closed form.

  11. Advanced Fibre Bragg Grating and Microfibre Bragg Grating Fabrication Techniques

    NASA Astrophysics Data System (ADS)

    Chung, Kit Man

    Fibre Bragg gratings (FBGs) have become a very important technology for communication systems and fibre optic sensing. Typically, FBGs are less than 10-mm long and are fabricated using fused silica uniform phase masks which become more expensive for longer length or non-uniform pitch. Generally, interference UV laser beams are employed to make long or complex FBGs, and this technique introduces critical precision and control issues. In this work, we demonstrate an advanced FBG fabrication system that enables the writing of long and complex gratings in optical fibres with virtually any apodisation profile, local phase and Bragg wavelength using a novel optical design in which the incident angles of two UV beams onto an optical fibre can be adjusted simultaneously by moving just one optical component, instead of two optics employed in earlier configurations, to vary the grating pitch. The key advantage of the grating fabrication system is that complex gratings can be fabricated by controlling the linear movements of two translation stages. In addition to the study of advanced grating fabrication technique, we also focus on the inscription of FBGs written in optical fibres with a cladding diameter of several ten's of microns. Fabrication of microfibres was investigated using a sophisticated tapering method. We also proposed a simple but practical technique to filter out the higher order modes reflected from the FBG written in microfibres via a linear taper region while the fundamental mode re-couples to the core. By using this technique, reflection from the microfibre Bragg grating (MFBG) can be effectively single mode, simplifying the demultiplexing and demodulation processes. MFBG exhibits high sensitivity to contact force and an MFBG-based force sensor was also constructed and tested to investigate their suitability for use as an invasive surgery device. Performance of the contact force sensor packaged in a conforming elastomer material compares favourably to one of the best-performing commercial contact force sensors in catheterization applications. The proposed sensor features extremely high sensitivity up to 1.37-mN, miniature size (2.4-mm) that meets standard specification, excellent linearity, low hysteresis, and magnetic resonance imaging compatibility.

  12. Multiple advanced surgical techniques to treat acquired seminal duct obstruction

    PubMed Central

    Jiang, Hong-Tao; Yuan, Qian; Liu, Yu; Liu, Zeng-Qin; Zhou, Zhen-Yu; Xiao, Ke-Feng; Yang, Jiang-Gen

    2014-01-01

    The aim of this study was to evaluate the outcomes of multiple advanced surgical treatments (i.e. microsurgery, laparoscopic surgery and endoscopic surgery) for acquired obstructive azoospermia. We analyzed the surgical outcomes of 51 patients with suspected acquired obstructive azoospermia consecutively who enrolled at our center between January 2009 and May 2013. Modified vasoepididymostomy, laparoscopically assisted vasovasostomy and transurethral incision of the ejaculatory duct with holmium laser were chosen and performed based on the different obstruction sites. The mean postoperative follow-up time was 22 months (range: 9 months to 52 months). Semen analyses were initiated at four postoperative weeks, followed by trimonthly (months 3, 6, 9 and 12) semen analyses, until no sperm was found at 12 months or until pregnancy was achieved. Patency was defined as >10,000 sperm ml?1 of semen. The obstruction sites, postoperative patency and natural pregnancy rate were recorded. Of 51 patients, 47 underwent bilateral or unilateral surgical reconstruction; the other four patients were unable to be treated with surgical reconstruction because of pelvic vas or intratesticular tubules obstruction. The reconstruction rate was 92.2% (47/51), and the patency rate and natural pregnancy rate were 89.4% (42/47) and 38.1% (16/42), respectively. No severe complications were observed. Using multiple advanced surgical techniques, more extensive range of seminal duct obstruction was accessible and correctable; thus, a favorable patency and pregnancy rate can be achieved. PMID:25337841

  13. Advances in the Rising Bubble Technique for discharge measurement

    NASA Astrophysics Data System (ADS)

    Hilgersom, Koen; Luxemburg, Willem; Willemsen, Geert; Bussmann, Luuk

    2014-05-01

    Already in the 19th century, d'Auria described a discharge measurement technique that applies floats to find the depth-integrated velocity (d'Auria, 1882). The basis of this technique was that the horizontal distance that the float travels on its way to the surface is the image of the integrated velocity profile over depth. Viol and Semenov (1964) improved this method by using air bubbles as floats, but still distances were measured manually until Sargent (1981) introduced a technique that could derive the distances from two photographs simultaneously taken from each side of the river bank. Recently, modern image processing techniques proved to further improve the applicability of the method (Hilgersom and Luxemburg, 2012). In the 2012 article, controlling and determining the rising velocity of an air bubble still appeared a major challenge for the application of this method. Ever since, laboratory experiments with different nozzle and tube sizes lead to advances in our self-made equipment enabling us to produce individual air bubbles with a more constant rising velocity. Also, we introduced an underwater camera to on-site determine the rising velocity, which is dependent on the water temperature and contamination, and therefore is site-specific. Camera measurements of the rising velocity proved successful in a laboratory and field setting, although some improvements to the setup are necessary to capture the air bubbles also at depths where little daylight penetrates. References D'Auria, L.: Velocity of streams; A new method to determine correctly the mean velocity of any perpendicular in rivers and canals, (The) American Engineers, 3, 1882. Hilgersom, K.P. and Luxemburg, W.M.J.: Technical Note: How image processing facilitates the rising bubble technique for discharge measurement, Hydrology and Earth System Sciences, 16(2), 345-356, 2012. Sargent, D.: Development of a viable method of stream flow measurement using the integrating float technique, Proceedings of the Institution of Civil Engineers (London), Part 2, 71, 1-15, 1981. Viol, V. and Semenov, V.: Experiments in measuring discharges in canals by the photo-integration method, Soviet Hydrol. Selected Pap, 2, 198-199, 1964.

  14. A Sensitive TLRH Targeted Imaging Technique for Ultrasonic Molecular Imaging

    PubMed Central

    Hu, Xiaowen; Zheng, Hairong; Kruse, Dustin E.; Sutcliffe, Patrick; Stephens, Douglas N.; Ferrara, Katherine W.

    2010-01-01

    The primary goals of ultrasound molecular imaging are the detection and imaging of ultrasound contrast agents (microbubbles), which are bound to specific vascular surface receptors. Imaging methods that can sensitively and selectively detect and distinguish bound microbubbles from freely circulating microbubbles (free microbubbles) and surrounding tissue are critically important for the practical application of ultrasound contrast molecular imaging. Microbubbles excited by low frequency acoustic pulses emit wide-band echoes with a bandwidth extending beyond 20 MHz; we refer to this technique as TLRH (transmission at a low frequency and reception at a high frequency). Using this wideband, transient echo, we have developed and implemented a targeted imaging technique incorporating a multi-frequency co-linear array and the Siemens Antares® imaging system. The multi-frequency co-linear array integrates a center 5.4 MHz array, used to receive echoes and produce radiation force, and two outer 1.5 MHz arrays used to transmit low frequency incident pulses. The targeted imaging technique makes use of an acoustic radiation force sub-sequence to enhance accumulation and a TLRH imaging sub-sequence to detect bound microbubbles. The radiofrequency (RF) data obtained from the TLRH imaging sub-sequence are processsed to separate echo signatures between tissue, free microbubbles, and bound microbubbles. By imaging biotin-coated microbubbles targeted to avidin-coated cellulose tubes, we demonstrate that the proposed method has a high contrast-to-tissue ratio (up to 34 dB) and a high sensitivity to bound microbubbles (with the ratio of echoes from bound microbubbles versus free microbubbles extending up to 23 dB). The effects of the imaging pulse acoustic pressure, the radiation force sub-sequence and the use of various slow-time filters on the targeted imaging quality are studied. The TLRH targeted imaging method is demonstrated in this study to provide sensitive and selective detection of bound microbubbles for ultrasound molecularly-targeted imaging. PMID:20178897

  15. Advances in molecular design and synthesis of regioregular polythiophenes.

    PubMed

    Osaka, Itaru; McCullough, Richard D

    2008-09-01

    Regioregular poly(3-alkylthiophene)s (rrP3ATs) are an important class of pi-conjugated polymers that can be used in plastic electronic devices such as solar cells and field-effect transistors. rrP3ATs can be ordered in three dimensions: conformational ordering along the backbone, pi-stacking of flat polymer chains, and lamellar stacking between chains. All of these features lead to the excellent electrical properties of these materials. Creative molecular design and advanced synthesis are critical in controlling the properties of the materials as well as their device performance. This Account reports the advances in molecular design of new functional polythiophenes as well as the associated polymerization methods. Many functionalized regioregular polythiophenes have been designed and synthesized and show fascinating properties such as high conductivity, mobility, chemosensitivity, liquid crystallinity, or chirality. The methods for the synthesis of rrP3ATs are also applicable to other functional side chains. Di- and triblock copolymers consisting of rrP3AT and polyacrylate or polystyrene have also been successfully synthesized, which can facilitate the assembly of the polythiophene segments. The synthesis of rrP3ATs has evolved into a simple and economical system in which the synthesis can be carried out quickly at room temperature and is thus suitable for large-scale manufacturing. Intensive study has revealed that the regioregular polymerization of 3-alkylthiophenes proceeds by a chain-growth mechanism and can be made into a living system. This feature enables precise control of the molecular weight and facile end-group functionalization of the polymer chains, leading to tailor-made regioregular polythiophenes for specific applications. In addition, researchers have recently designed and synthesized regiosymmetric polythiophenesthese are regioregular but not coupled in a head-to-tail fashionby various methods. These reports indicate that these regiosymmetric polymers show very high mobilities when used in field-effect transistors due to their highly ordered structure. The remarkable performance of regioregular polythiophenes in recent years has allowed for the rapid development in printable electronics and seems destined to lead to further advances in this field. PMID:18729480

  16. Recent advances on host plants and expression cassettes' structure and function in plant molecular pharming.

    PubMed

    Makhzoum, Abdullah; Benyammi, Roukia; Moustafa, Khaled; Trémouillaux-Guiller, Jocelyne

    2014-04-01

    Plant molecular pharming is a promising system to produce important recombinant proteins such as therapeutic antibodies, pharmaceuticals, enzymes, growth factors, and vaccines. The system provides an interesting alternative method to the direct extraction of proteins from inappropriate source material while offering the possibility to overcome problems related to product safety and source availability. Multiple factors including plant hosts, genes of interest, expression vector cassettes, and extraction and purification techniques play important roles in the plant molecular pharming. Plant species, as a biosynthesis platform, are a crucial factor in achieving high yields of recombinant protein in plant. The choice of recombinant gene and its expression strategy is also of great importance in ensuring a high amount of the recombinant proteins. Many studies have been conducted to improve expression, accumulation, and purification of the recombinant protein from molecular pharming systems. Re-engineered vectors and expression cassettes are also pivotal tools in enhancing gene expression at the transcription and translation level, and increasing protein accumulation, stability, retention and targeting of specific organelles. In this review, we report recent advances and strategies of plant molecular pharming while focusing on the choice of plant hosts and the role of some molecular pharming elements and approaches: promoters, codon optimization, signal sequences, and peptides used for upstream design, purification and downstream processing. PMID:23959796

  17. Simple technique for sequential Q-switching of molecular lasers.

    NASA Technical Reports Server (NTRS)

    Lucht, R. A.; Allario, F.; Jarrett, O., Jr.

    1972-01-01

    A simple technique for sequentially Q-switching molecular lasers is discussed in which an optical scanner is used as an optical folding element in a laser cavity consisting of a stationary diffraction grating and partially reflecting mirror. Sequential Q-switching of a conventional CO2 laser is demonstrated in which over sixty-two transitions between 9.2 and 10.8 microns are observed. Rapid repetition rates (200 Hz) and narrow laser pulses (less than 5 microsec) allow conventional signal processing techniques to be used with this multiwavelength laser source which is a versatile tool for laser propagation studies, absorption spectroscopy, and gain measurements. Results of a preliminary experiment demonstrating the utility of measuring selective absorption of CO2 laser wavelengths by C2H4 are shown.

  18. Recent advances in the molecular basis of frontotemporal dementia

    PubMed Central

    Rademakers, Rosa; Neumann, Manuela; Mackenzie, Ian R. A.

    2013-01-01

    Frontotemporal dementia (FTD) is a clinical syndrome with heterogeneous molecular basis. Until recently, our knowledge was limited to a minority of cases associated with abnormalities of the tau protein or gene (MAPT). However, in 2006, mutations in progranulin (GRN) were discovered as another important cause of familial FTD. That same year, TAR DNA binding protein 43 (TDP-43) was identified as the pathological protein in the most common subtypes of FTD and ALS. Since then, significant efforts have been made to understand the normal functions and regulation of GRN and TDP-43 and their roles in neurodegeneration. More recently, other DNA/RNA binding proteins (FUS, EWS and TAF15) were identified as pathological proteins in most of the remaining cases of FTD. And just six months ago, abnormal expansion of a hexanucleotide repeat in C9ORF72 was found to be the most common genetic cause of both FTD and ALS. With this remarkable progress, it appears that all the common FTD-causing genes have now been discovered and the major pathological proteins identified. This review highlights recent advances in the molecular aspects of FTD, which will provide the basis for improved patient care through the future development of more targeted diagnostic tests and therapies. PMID:22732773

  19. Ciceromics: Advancement in Genomics and Recent Molecular Techniques

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genomics is a branch of science that decodes the encrypted information in DNA and reveals information such as the number of genes, genome organization and content. This information has tremendous application in agriculture, evolutionary biology and other areas of science. Although genomics has allow...

  20. Nanocrystalline materials: recent advances in crystallographic characterization techniques

    PubMed Central

    Ringe, Emilie

    2014-01-01

    Most properties of nanocrystalline materials are shape-dependent, providing their exquisite tunability in optical, mechanical, electronic and catalytic properties. An example of the former is localized surface plasmon resonance (LSPR), the coherent oscillation of conduction electrons in metals that can be excited by the electric field of light; this resonance frequency is highly dependent on both the size and shape of a nanocrystal. An example of the latter is the marked difference in catalytic activity observed for different Pd nanoparticles. Such examples highlight the importance of particle shape in nanocrystalline materials and their practical applications. However, one may ask ‘how are nanoshapes created?’, ‘how does the shape relate to the atomic packing and crystallography of the material?’, ‘how can we control and characterize the external shape and crystal structure of such small nanocrystals?’. This feature article aims to give the reader an overview of important techniques, concepts and recent advances related to these questions. Nucleation, growth and how seed crystallography influences the final synthesis product are discussed, followed by shape prediction models based on seed crystallography and thermodynamic or kinetic parameters. The crystallographic implications of epitaxy and orientation in multilayered, core-shell nanoparticles are overviewed, and, finally, the development and implications of novel, spatially resolved analysis tools are discussed. PMID:25485133

  1. Development of advanced strain diagnostic techniques for reactor environments.

    SciTech Connect

    Fleming, Darryn D.; Holschuh, Thomas Vernon,; Miller, Timothy J.; Hall, Aaron Christopher; Urrea, David Anthony,; Parma, Edward J.,

    2013-02-01

    The following research is operated as a Laboratory Directed Research and Development (LDRD) initiative at Sandia National Laboratories. The long-term goals of the program include sophisticated diagnostics of advanced fuels testing for nuclear reactors for the Department of Energy (DOE) Gen IV program, with the future capability to provide real-time measurement of strain in fuel rod cladding during operation in situ at any research or power reactor in the United States. By quantifying the stress and strain in fuel rods, it is possible to significantly improve fuel rod design, and consequently, to improve the performance and lifetime of the cladding. During the past year of this program, two sets of experiments were performed: small-scale tests to ensure reliability of the gages, and reactor pulse experiments involving the most viable samples in the Annulated Core Research Reactor (ACRR), located onsite at Sandia. Strain measurement techniques that can provide useful data in the extreme environment of a nuclear reactor core are needed to characterize nuclear fuel rods. This report documents the progression of solutions to this issue that were explored for feasibility in FY12 at Sandia National Laboratories, Albuquerque, NM.

  2. Hybrid inverse lithography techniques for advanced hierarchical memories

    NASA Astrophysics Data System (ADS)

    Xiao, Guangming; Hooker, Kevin; Irby, Dave; Zhang, Yunqiang; Ward, Brian; Cecil, Tom; Hall, Brett; Lee, Mindy; Kim, Dave; Lucas, Kevin

    2014-03-01

    Traditional segment-based model-based OPC methods have been the mainstream mask layout optimization techniques in volume production for memory and embedded memory devices for many device generations. These techniques have been continually optimized over time to meet the ever increasing difficulties of memory and memory periphery patterning. There are a range of difficult issues for patterning embedded memories successfully. These difficulties include the need for a very high level of symmetry and consistency (both within memory cells themselves and between cells) due to circuit effects such as noise margin requirements in SRAMs. Memory cells and access structures consume a large percentage of area in embedded devices so there is a very high return from shrinking the cell area as much as possible. This aggressive scaling leads to very difficult resolution, 2D CD control and process window requirements. Additionally, the range of interactions between mask synthesis corrections of neighboring areas can extend well beyond the size of the memory cell, making it difficult to fully take advantage of the inherent designed cell hierarchy in mask pattern optimization. This is especially true for non-traditional (i.e., less dependent on geometric rule) OPC/RET methods such as inverse lithography techniques (ILT) which inherently have more model-based decisions in their optimizations. New inverse methods such as model-based SRAF placement and ILT are, however, well known to have considerable benefits in finding flexible mask pattern solutions to improve process window, improve 2D CD control, and improve resolution in ultra-dense memory patterns. They also are known to reduce recipe complexity and provide native MRC compliant mask pattern solutions. Unfortunately, ILT is also known to be several times slower than traditional OPC methods due to the increased computational lithographic optimizations it performs. In this paper, we describe and present results for a methodology to greatly improve the ability of ILT to optimize advanced embedded memory designs while retaining significant hierarchy and cell design symmetry, therefore, have good turnaround time and CD uniformity. This paper will explain the enhancements which have been developed in order to overcome the traditional difficulties listed above. These enhancements are in the categories of local CD control, global chip processing options, process window benefit, turn-around time and hierarchy retention.

  3. Clinical Advances in Molecular Biomarkers for Cancer Diagnosis and Therapy

    PubMed Central

    Sethi, Seema; Ali, Shadan; Philip, Philip A.; Sarkar, Fazlul H.

    2013-01-01

    Cancer diagnosis is currently undergoing a paradigm shift with the incorporation of molecular biomarkers as part of routine diagnostic panel. The molecular alteration ranges from those involving the DNA, RNA, microRNAs (miRNAs) and proteins. The miRNAs are recently discovered small non-coding endogenous single-stranded RNAs that critically regulates the development, invasion and metastasis of cancers. They are altered in cancers and have the potential to serve as diagnostic markers for cancer. Moreover, deregulating their activity offers novel cancer therapeutic approaches. The availability of high throughput techniques for the identification of altered cellular molecules allowed their use in cancer diagnosis. Their application to a variety of body specimens from blood to tissues has been helpful for appreciating their use in the clinical context. The development of innovative antibodies for immunohistochemical detection of proteins also assists in diagnosis and risk stratification. Overall, the novel cancer diagnostic tools have extended their application as prognostic risk factors and can be used as targets for personalized medicine. PMID:23863689

  4. Advanced Geological Remote Sensing Description of the course: This course introduces the advanced theory and techniques of

    E-print Network

    Gilbes, Fernando

    GEOL 6225 Advanced Geological Remote Sensing Description of the course: This course introduces the advanced theory and techniques of remote sensing tools with emphasis on the geosciences. It also includes: Remote Sensing of the Environment John R. Jensen (2007) Second Edition. Pearson Prentice Hall. Reference

  5. ADVANCED TECHNIQUES FOR RESERVOIR SIMULATION AND MODELING OF NONCONVENTIONAL WELLS

    SciTech Connect

    Louis J. Durlofsky; Khalid Aziz

    2004-08-20

    Nonconventional wells, which include horizontal, deviated, multilateral and ''smart'' wells, offer great potential for the efficient management of oil and gas reservoirs. These wells are able to contact larger regions of the reservoir than conventional wells and can also be used to target isolated hydrocarbon accumulations. The use of nonconventional wells instrumented with downhole inflow control devices allows for even greater flexibility in production. Because nonconventional wells can be very expensive to drill, complete and instrument, it is important to be able to optimize their deployment, which requires the accurate prediction of their performance. However, predictions of nonconventional well performance are often inaccurate. This is likely due to inadequacies in some of the reservoir engineering and reservoir simulation tools used to model and optimize nonconventional well performance. A number of new issues arise in the modeling and optimization of nonconventional wells. For example, the optimal use of downhole inflow control devices has not been addressed for practical problems. In addition, the impact of geological and engineering uncertainty (e.g., valve reliability) has not been previously considered. In order to model and optimize nonconventional wells in different settings, it is essential that the tools be implemented into a general reservoir simulator. This simulator must be sufficiently general and robust and must in addition be linked to a sophisticated well model. Our research under this five year project addressed all of the key areas indicated above. The overall project was divided into three main categories: (1) advanced reservoir simulation techniques for modeling nonconventional wells; (2) improved techniques for computing well productivity (for use in reservoir engineering calculations) and for coupling the well to the simulator (which includes the accurate calculation of well index and the modeling of multiphase flow in the wellbore); and (3) accurate approaches to account for the effects of reservoir heterogeneity and for the optimization of nonconventional well deployment. An overview of our progress in each of these main areas is as follows. A general purpose object-oriented research simulator (GPRS) was developed under this project. The GPRS code is managed using modern software management techniques and has been deployed to many companies and research institutions. The simulator includes general black-oil and compositional modeling modules. The formulation is general in that it allows for the selection of a wide variety of primary and secondary variables and accommodates varying degrees of solution implicitness. Specifically, we developed and implemented an IMPSAT procedure (implicit in pressure and saturation, explicit in all other variables) for compositional modeling as well as an adaptive implicit procedure. Both of these capabilities allow for efficiency gains through selective implicitness. The code treats cell connections through a general connection list, which allows it to accommodate both structured and unstructured grids. The GPRS code was written to be easily extendable so new modeling techniques can be readily incorporated. Along these lines, we developed a new dual porosity module compatible with the GPRS framework, as well as a new discrete fracture model applicable for fractured or faulted reservoirs. Both of these methods display substantial advantages over previous implementations. Further, we assessed the performance of different preconditioners in an attempt to improve the efficiency of the linear solver. As a result of this investigation, substantial improvements in solver performance were achieved.

  6. Weldability and joining techniques for advanced fossil energy system alloys

    SciTech Connect

    Lundin, C.D.; Qiao, C.Y.P.; Liu, W.; Yang, D.; Zhou, G.; Morrison, M.

    1998-05-01

    The efforts represent the concerns for the basic understanding of the weldability and fabricability of the advanced high temperature alloys so necessary to affect increases in the efficiency of the next generation Fossil Energy Power Plants. The effort was divided into three tasks with the first effort dealing with the welding and fabrication behavior of 310HCbN (HR3C), the second task details the studies aimed at understanding the weldability of a newly developed 310TaN high temperature stainless (a modification of 310 stainless) and Task 3 addressed the cladding of austenitic tubing with Iron-Aluminide using the GTAW process. Task 1 consisted of microstructural studies on 310HCbN and the development of a Tube Weldability test which has applications to production welding techniques as well as laboratory weldability assessments. In addition, the evaluation of ex-service 310HCbN which showed fireside erosion and cracking at the attachment weld locations was conducted. Task 2 addressed the behavior of the newly developed 310 TaN modification of standard 310 stainless steel and showed that the weldability was excellent and that the sensitization potential was minimal for normal welding and fabrication conditions. The microstructural evolution during elevated temperature testing was characterized and the second phase particles evolved upon aging were identified. Task 3 details the investigation undertaken to clad 310HCbN tubing with Iron Aluminide and developed welding conditions necessary to provide a crack free cladding. The work showed that both a preheat and a post-heat was necessary for crack free deposits and the effect of a third element on the cracking potential was defined together with the effect of the aluminum level for optimum weldability.

  7. Investigation of joining techniques for advanced austenitic alloys

    SciTech Connect

    Lundin, C.D.; Qiao, C.Y.P.; Kikuchi, Y.; Shi, C.; Gill, T.P.S.

    1991-05-01

    Modified Alloys 316 and 800H, designed for high temperature service, have been developed at Oak Ridge National Laboratory. Assessment of the weldability of the advanced austenitic alloys has been conducted at the University of Tennessee. Four aspects of weldability of the advanced austenitic alloys were included in the investigation.

  8. Marie Curie Initial Training Network in Advanced Techniques in Computational Mechanics Page 1 of 4

    E-print Network

    Huerta, Antonio

    Marie Curie Initial Training Network in Advanced Techniques in Computational Mechanics ATCoMe Page): ....................................... ............................................................................................................................... ............................................................................................................................... ............................................................................................................................... ............................................................................................................................... ............................................................................................................................... #12;Marie Curie Initial Training Network in Advanced Techniques in Computational Mechanics ATCoMe Page Speaking Reading Writing English French Spanish German Portuguese #12;Marie Curie Initial Training Network

  9. 75 FR 44015 - Certain Semiconductor Products Made by Advanced Lithography Techniques and Products Containing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ... Certain Semiconductor Products Made by Advanced Lithography Techniques and Products Containing Same... certain semiconductor products made by advanced lithography techniques and products containing same by... information contained therein, is available for inspection during official business hours (8:45 a.m. to 5:15...

  10. ADVANCED NANOIMPRINT TECHNIQUE FOR MULTILAYER STRUCTURES AND FUNCTIONAL POLYMER APPLICATIONS 

    E-print Network

    Park, Hyunsoo

    2010-07-14

    in thermoplastic polymers using optimized nanoimprint lithography techniques such as layer-transfer and transfer-bonding methods are developed in this dissertation work. The capability and flexibility of the techniques developed here are expected to have deep...

  11. Applied Protein and Molecular Techniques for Characterization of B Cell Neoplasms in Horses.

    PubMed

    Badial, Peres R; Tallmadge, Rebecca L; Miller, Steven; Stokol, Tracy; Richards, Kristy; Borges, Alexandre S; Felippe, M Julia B

    2015-11-01

    Mature B cell neoplasms cover a spectrum of diseases involving lymphoid tissues (lymphoma) or blood (leukemia), with an overlap between these two presentations. Previous studies describing equine lymphoid neoplasias have not included analyses of clonality using molecular techniques. The objective of this study was to use molecular techniques to advance the classification of B cell lymphoproliferative diseases in five adult equine patients with a rare condition of monoclonal gammopathy, B cell leukemia, and concurrent lymphadenopathy (lymphoma/leukemia). The B cell neoplasms were phenotypically characterized by gene and cell surface molecule expression, secreted immunoglobulin (Ig) isotype concentrations, Ig heavy-chain variable (IGHV) region domain sequencing, and spectratyping. All five patients had hyperglobulinemia due to IgG1 or IgG4/7 monoclonal gammopathy. Peripheral blood leukocyte immunophenotyping revealed high proportions of IgG1- or IgG4/7-positive cells and relative T cell lymphopenia. Most leukemic cells lacked the surface B cell markers CD19 and CD21. IGHG1 or IGHG4/7 gene expression was consistent with surface protein expression, and secreted isotype and Ig spectratyping revealed one dominant monoclonal peak. The mRNA expression of the B cell-associated developmental genes EBF1, PAX5, and CD19 was high compared to that of the plasma cell-associated marker CD38. Sequence analysis of the IGHV domain of leukemic cells revealed mutated Igs. In conclusion, the protein and molecular techniques used in this study identified neoplastic cells compatible with a developmental transition between B cell and plasma cell stages, and they can be used for the classification of equine B cell lymphoproliferative disease. PMID:26311245

  12. TWS Symposium Application of molecular and genetic techniques to wildlife epidemiology

    E-print Network

    Ernest, Holly

    TWS Symposium ­ Application of molecular and genetic techniques to wildlife epidemiology Genetics primer: State of technology and applications for wildlife disease ecology & epidemiology View this online

  13. Advanced Characterization of Molecular Interactions in TALSPEAK-like Separations Systems

    SciTech Connect

    Nash, Kenneth; Guelis, Artem; Lumetta, Gregg J.; Sinkov, Sergey

    2015-10-21

    Combining unit operations in advanced aqueous reprocessing schemes brings obvious process compactness advantages, but at the same time greater complexity in process design and operation. Unraveling these interactions requires increasingly sophisticated analytical tools and unique approaches for adequate analysis and characterization that probe molecular scale interactions. Conventional slope analysis methods of solvent extraction are too indirect to provide much insight into such interactions. This project proposed the development and verification of several analytical tools based on studies of TALSPEAK-like aqueous processes. As such, the chemistry of trivalent fission product lanthanides, americium, curium, plutonium, neptunium and uranium figure prominently in these studies. As the project was executed, the primary focus fell upon the chemistry or trivalent lanthanides and actinides. The intent of the investigation was to compare and contrast the results from these various complementary techniques/studies to provide a stronger basis for predicting the performance of extractant/diluent mixtures as media for metal ion separations. As many/most of these techniques require the presence of metal ions at elevated concentrations, it was expected that these studies would take this investigation into the realm of patterns of supramolecular organization of metal complexes and extractants in concentrated aqueous/organic media. We expected to advance knowledge of the processes that enable and limit solvent extraction reactions as a result of the application of fundamental chemical principles to explaining interactions in complex media.

  14. Mechanical Properties of Nanostructured Materials Determined Through Molecular Modeling Techniques

    NASA Technical Reports Server (NTRS)

    Clancy, Thomas C.; Gates, Thomas S.

    2005-01-01

    The potential for gains in material properties over conventional materials has motivated an effort to develop novel nanostructured materials for aerospace applications. These novel materials typically consist of a polymer matrix reinforced with particles on the nanometer length scale. In this study, molecular modeling is used to construct fully atomistic models of a carbon nanotube embedded in an epoxy polymer matrix. Functionalization of the nanotube which consists of the introduction of direct chemical bonding between the polymer matrix and the nanotube, hence providing a load transfer mechanism, is systematically varied. The relative effectiveness of functionalization in a nanostructured material may depend on a variety of factors related to the details of the chemical bonding and the polymer structure at the nanotube-polymer interface. The objective of this modeling is to determine what influence the details of functionalization of the carbon nanotube with the polymer matrix has on the resulting mechanical properties. By considering a range of degree of functionalization, the structure-property relationships of these materials is examined and mechanical properties of these models are calculated using standard techniques.

  15. A Coupled Meshless Technique/Molecular Dynamics Approach for Deformation Characterization of Mono-crystalline Metal

    SciTech Connect

    Gu, Y. T.; Yarlagadda, Prasad K. D. V.

    2010-05-21

    This paper presents a multiscale study using the coupled Meshless technique/Molecular Dynamics (M{sup 2}) for exploring the deformation mechanism of mono-crystalline metal (focus on copper) under uniaxial tension. In M{sup 2}, an advanced transition algorithm using transition particles is employed to ensure the compatibility of both displacements and their gradients, and an effective local quasi-continuum approach is also applied to obtain the equivalent continuum strain energy density based on the atomistic potentials and Cauchy-Born rule. The key parameters used in M{sup 2} are firstly investigated using a benchmark problem. Then, M{sup 2} is applied to the multiscale simulation for a mono-crystalline copper bar. It has found that the mono-crystalline copper has very good elongation property, and the ultimate strength and Young's modulus are much higher than those obtained in macro-scale.

  16. Advanced endovascular techniques for thoracic and abdominal aortic dissections.

    PubMed

    Kölbel, T; Diener, H; Larena-Avellaneda, A; Debus, S

    2013-02-01

    Endovascular treatment of aortic dissection is still in its infancy and consists usually of implantation of thoracic tubular stent-grafts to cover the proximal entry tear and redirect flow into the true lumen. Large registries comparing endovascular treatment by thoracic endovascular aortic repair (TEVAR) with open surgery for aortic dissection of the descending aorta have demonstrated a clear benefit for endovascular treatment with lower mortality and morbidity rates turning TEVAR into the standard treatment for complicated type B aortic dissection. With this momentum of success endovascular techniques continue to challenge open surgical techniques also in the aortic arch and the ascending aorta. TEVAR for aortic dissection has become more complex requiring an individualized treatment strategy as endovascular techniques have developed with the advent of new devices and increased experience of the operators. In many cases straight implantation of a thoracic tubular stent-graft is sufficient. But as rerouting of the blood flow can also change perfusion of vital side-branches the endovascular operator needs to have a large armamentarium of techniques and adjunctive procedures in order to sufficiently address the individual patient morphology. This chapter reviews a variety of endovascular techniques including access techniques, proximal sealing, the Petticoat-technique, false lumen deployment, fenestration techniques, branch vessel stenting and false lumen obstruction by various techniques. PMID:23443592

  17. Tumor Functional and Molecular Imaging Utilizing Ultrasound and Ultrasound-Mediated Optical Techniques

    PubMed Central

    Yuan, Baohong; Rychak, Joshua

    2014-01-01

    Tumor functional and molecular imaging has significantly contributed to cancer preclinical research and clinical applications. Among typical imaging modalities, ultrasonic and optical techniques are two commonly used methods; both share several common features such as cost efficiency, absence of ionizing radiation, relatively inexpensive contrast agents, and comparable maximum-imaging depth. Ultrasonic and optical techniques are also complementary in imaging resolution, molecular sensitivity, and imaging space (vascular and extravascular). The marriage between ultrasonic and optical techniques takes advantages of both techniques. This review introduces tumor functional and molecular imaging using microbubble-based ultrasound and ultrasound-mediated optical imaging techniques. PMID:23219728

  18. Advancing the frontiers in nanocatalysis, biointerfaces, and renewable energy conversion by innovations of surface techniques.

    PubMed

    Somorjai, Gabor A; Frei, Heinz; Park, Jeong Y

    2009-11-25

    The challenge of chemistry in the 21st century is to achieve 100% selectivity of the desired product molecule in multipath reactions ("green chemistry") and develop renewable energy based processes. Surface chemistry and catalysis play key roles in this enterprise. Development of in situ surface techniques such as high-pressure scanning tunneling microscopy, sum frequency generation (SFG) vibrational spectroscopy, time-resolved Fourier transform infrared methods, and ambient pressure X-ray photoelectron spectroscopy enabled the rapid advancement of three fields: nanocatalysts, biointerfaces, and renewable energy conversion chemistry. In materials nanoscience, synthetic methods have been developed to produce monodisperse metal and oxide nanoparticles (NPs) in the 0.8-10 nm range with controlled shape, oxidation states, and composition; these NPs can be used as selective catalysts since chemical selectivity appears to be dependent on all of these experimental parameters. New spectroscopic and microscopic techniques have been developed that operate under reaction conditions and reveal the dynamic change of molecular structure of catalysts and adsorbed molecules as the reactions proceed with changes in reaction intermediates, catalyst composition, and oxidation states. SFG vibrational spectroscopy detects amino acids, peptides, and proteins adsorbed at hydrophobic and hydrophilic interfaces and monitors the change of surface structure and interactions with coadsorbed water. Exothermic reactions and photons generate hot electrons in metal NPs that may be utilized in chemical energy conversion. The photosplitting of water and carbon dioxide, an important research direction in renewable energy conversion, is discussed. PMID:19919130

  19. Advancing the Frontiers in Nanocatalysis, Biointerfaces, and Renewable Energy Conversion by Innovations of Surface Techniques

    SciTech Connect

    Somorjai, G.A.; Frei, H.; Park, J.Y.

    2009-07-23

    The challenge of chemistry in the 21st century is to achieve 100% selectivity of the desired product molecule in multipath reactions ('green chemistry') and develop renewable energy based processes. Surface chemistry and catalysis play key roles in this enterprise. Development of in situ surface techniques such as high-pressure scanning tunneling microscopy, sum frequency generation (SFG) vibrational spectroscopy, time-resolved Fourier transform infrared methods, and ambient pressure X-ray photoelectron spectroscopy enabled the rapid advancement of three fields: nanocatalysts, biointerfaces, and renewable energy conversion chemistry. In materials nanoscience, synthetic methods have been developed to produce monodisperse metal and oxide nanoparticles (NPs) in the 0.8-10 nm range with controlled shape, oxidation states, and composition; these NPs can be used as selective catalysts since chemical selectivity appears to be dependent on all of these experimental parameters. New spectroscopic and microscopic techniques have been developed that operate under reaction conditions and reveal the dynamic change of molecular structure of catalysts and adsorbed molecules as the reactions proceed with changes in reaction intermediates, catalyst composition, and oxidation states. SFG vibrational spectroscopy detects amino acids, peptides, and proteins adsorbed at hydrophobic and hydrophilic interfaces and monitors the change of surface structure and interactions with coadsorbed water. Exothermic reactions and photons generate hot electrons in metal NPs that may be utilized in chemical energy conversion. The photosplitting of water and carbon dioxide, an important research direction in renewable energy conversion, is discussed.

  20. Development of Advanced In-Situ Techniques for Chemistry Monitoring and Corrosion Mitigation in SCWO Environments

    SciTech Connect

    Macdonald, D. D.; Lvov, S. N.

    2000-03-31

    This project is developing sensing technologies and corrosion monitoring techniques for use in super critical water oxidation (SCWO) systems to reduce the volume of mixed low-level nuclear waste by oxidizing organic components in a closed cycle system where CO2 and other gaseous oxides are produced, leaving the radioactive elements concentrated in ash. The technique uses water at supercritical temperatures under highly oxidized conditions by maintaining a high fugacity of molecular oxygen in the system, which causes high corrosion rates of even the most corrosive resistant reactor materials. This project significantly addresses the high corrosion shortcoming through development of (a) advanced electrodes and sensors for in situ potentiometric monitoring of pH in high subcritical and supercritical aqueous solutions, (b) an approach for evaluating the association constants for 1-1 aqueous electrolytes using a flow-through electrochemical thermocell; (c) an electrochemical noise sensor for the in situ measurement of corrosion rate in subcritical and supercritical aqueous systems; (d) a model for estimating the effect of pressure on reaction rates, including corrosion reactions, in high subcritical and supercritical aqueous systems. The project achieved all objectives, except for installing some of the sensors into a fully operating SCWO system.

  1. Microcomposition of Human Urinary Calculi Using Advanced Imaging Techniques

    E-print Network

    insight to prevent and treat stone formation. Key Words: kidney, diagnostic imaging, nephrolithiasis on the molecular composition of stones, which is vital when studying early stone pathogenesis. We used synchrotron on a m (0.0001 cm) scale. Materials and Methods: Human stone samples were obtained during serial

  2. Advanced NDE techniques for quantitative characterization of aircraft

    NASA Technical Reports Server (NTRS)

    Heyman, Joseph S.; Winfree, William P.

    1990-01-01

    Recent advances in nondestructive evaluation (NDE) at NASA Langley Research Center and their applications that have resulted in quantitative assessment of material properties based on thermal and ultrasonic measurements are reviewed. Specific applications include ultrasonic determination of bolt tension, ultrasonic and thermal characterization of bonded layered structures, characterization of composite materials, and disbonds in aircraft skins.

  3. Bricklaying Curriculum: Advanced Bricklaying Techniques. Instructional Materials. Revised.

    ERIC Educational Resources Information Center

    Turcotte, Raymond J.; Hendrix, Laborn J.

    This curriculum guide is designed to assist bricklaying instructors in providing performance-based instruction in advanced bricklaying. Included in the first section of the guide are units on customized or architectural masonry units; glass block; sills, lintels, and copings; and control (expansion) joints. The next two units deal with cut,…

  4. Cocoa Growers' Bulletin No.52 November 2000 APPLICATION OF THE TECHNIQUES OF MOLECULAR BIOLOGY

    E-print Network

    Griffith, Gareth

    process. The most powerful of these tools are those of molecular biology, which permit direct analysis of molecular biology for each of these are described below Phytophthora Pod Rot (PPR), also widely knownCocoa Growers' Bulletin No.52 November 2000 - 46 - APPLICATION OF THE TECHNIQUES OF MOLECULAR

  5. How Molecular Structure Affects Mechanical Properties of an Advanced Polymer

    NASA Technical Reports Server (NTRS)

    Nicholson, Lee M.; Whitley, Karen S.; Gates, Thomas S.; Hinkley, Jeffrey A.

    2000-01-01

    density was performed over a range of temperatures below the glass transition temperature. The physical characterization, elastic properties and notched tensile strength all as a function of molecular weight and test temperature were determined. For the uncrosslinked SI material, it was shown that notched tensile strength is a strong function of both temperature and molecular weight, whereas stiffness is only a strong function of temperature. For the crosslinked PETI-SI material, it was shown that the effect of crosslinking significantly enhances the mechanical performance of the low molecular weight material; comparable to that exhibited by the high molecular weight material.

  6. Backscattered Electron Microscopy as an Advanced Technique in Petrography.

    ERIC Educational Resources Information Center

    Krinsley, David Henry; Manley, Curtis Robert

    1989-01-01

    Three uses of this method with sandstone, desert varnish, and granite weathering are described. Background information on this technique is provided. Advantages of this type of microscopy are stressed. (CW)

  7. Tagging and Purifying Proteins to Teach Molecular Biology and Advanced Biochemistry

    ERIC Educational Resources Information Center

    Roecklein-Canfield, Jennifer A.; Lopilato, Jane

    2004-01-01

    Two distinct courses, "Molecular Biology" taught by the Biology Department and "Advanced Biochemistry" taught by the Chemistry Department, complement each other and, when taught in a coordinated and integrated way, can enhance student learning and understanding of complex material. "Molecular Biology" is a comprehensive lecture-based course with a…

  8. Application of advanced cytometric and molecular technologies to minimal residual disease monitoring

    NASA Astrophysics Data System (ADS)

    Leary, James F.; He, Feng; Reece, Lisa M.

    2000-04-01

    Minimal residual disease monitoring presents a number of theoretical and practical challenges. Recently it has been possible to meet some of these challenges by combining a number of new advanced biotechnologies. To monitor the number of residual tumor cells requires complex cocktails of molecular probes that collectively provide sensitivities of detection on the order of one residual tumor cell per million total cells. Ultra-high-speed, multi parameter flow cytometry is capable of analyzing cells at rates in excess of 100,000 cells/sec. Residual tumor selection marker cocktails can be optimized by use of receiver operating characteristic analysis. New data minimizing techniques when combined with multi variate statistical or neural network classifications of tumor cells can more accurately predict residual tumor cell frequencies. The combination of these techniques can, under at least some circumstances, detect frequencies of tumor cells as low as one cell in a million with an accuracy of over 98 percent correct classification. Detection of mutations in tumor suppressor genes requires insolation of these rare tumor cells and single-cell DNA sequencing. Rare residual tumor cells can be isolated at single cell level by high-resolution single-cell cell sorting. Molecular characterization of tumor suppressor gene mutations can be accomplished using a combination of single- cell polymerase chain reaction amplification of specific gene sequences followed by TA cloning techniques and DNA sequencing. Mutations as small as a single base pair in a tumor suppressor gene of a single sorted tumor cell have been detected using these methods. Using new amplification procedures and DNA micro arrays it should be possible to extend the capabilities shown in this paper to screening of multiple DNA mutations in tumor suppressor and other genes on small numbers of sorted metastatic tumor cells.

  9. Nondestructive Evaluation of Thick Concrete Using Advanced Signal Processing Techniques

    SciTech Connect

    Clayton, Dwight A; Barker, Alan M; Santos-Villalobos, Hector J; Albright, Austin P; Hoegh, Kyle; Khazanovich, Lev

    2015-09-01

    The purpose of the U.S. Department of Energy Office of Nuclear Energy’s Light Water Reactor Sustainability (LWRS) Program is to develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the operating lifetimes of nuclear power plants (NPPs) beyond 60 years [1]. Since many important safety structures in an NPP are constructed of concrete, inspection techniques must be developed and tested to evaluate the internal condition. In-service containment structures generally do not allow for the destructive measures necessary to validate the accuracy of these inspection techniques. This creates a need for comparative testing of the various nondestructive evaluation (NDE) measurement techniques on concrete specimens with known material properties, voids, internal microstructure flaws, and reinforcement locations.

  10. Antenna Advancement Techniques and Integration of RFID Electronics on Organic Substrates for UHF RFID Applications in

    E-print Network

    Tentzeris, Manos

    Antenna Advancement Techniques and Integration of RFID Electronics on Organic Substrates for UHF RFID Applications in Automotive Sensing and Vehicle Security Li Yang, Amin Rida, Jiexin Li, and Manos M requirements and advanced approaches for improved performance UHF radio frequency identification (RFID) tags

  11. Advances Towards Synthetic Machines at the Molecular and Nanoscale Level

    PubMed Central

    Konstas, Kristina; Langford, Steven J.; Latter, Melissa J.

    2010-01-01

    The fabrication of increasingly smaller machines to the nanometer scale can be achieved by either a “top-down” or “bottom-up” approach. While the former is reaching its limits of resolution, the latter is showing promise for the assembly of molecular components, in a comparable approach to natural systems, to produce functioning ensembles in a controlled and predetermined manner. In this review we focus on recent progress in molecular systems that act as molecular machine prototypes such as switches, motors, vehicles and logic operators. PMID:20640163

  12. Advances in reduction techniques for tire contact problems

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K.

    1995-01-01

    Some recent developments in reduction techniques, as applied to predicting the tire contact response and evaluating the sensitivity coefficients of the different response quantities, are reviewed. The sensitivity coefficients measure the sensitivity of the contact response to variations in the geometric and material parameters of the tire. The tire is modeled using a two-dimensional laminated anisotropic shell theory with the effects of variation in geometric and material parameters, transverse shear deformation, and geometric nonlinearities included. The contact conditions are incorporated into the formulation by using a perturbed Lagrangian approach with the fundamental unknowns consisting of the stress resultants, the generalized displacements, and the Lagrange multipliers associated with the contact conditions. The elemental arrays are obtained by using a modified two-field, mixed variational principle. For the application of reduction techniques, the tire finite element model is partitioned into two regions. The first region consists of the nodes that are likely to come in contact with the pavement, and the second region includes all the remaining nodes. The reduction technique is used to significantly reduce the degrees of freedom in the second region. The effectiveness of the computational procedure is demonstrated by a numerical example of the frictionless contact response of the space shuttle nose-gear tire, inflated and pressed against a rigid flat surface. Also, the research topics which have high potential for enhancing the effectiveness of reduction techniques are outlined.

  13. Advanced imaging techniques for the study of plant growth and development

    PubMed Central

    Sozzani, Rosangela; Busch, Wolfgang; Spalding, Edgar P.; Benfey, Philip N.

    2014-01-01

    A variety of imaging methodologies are being used to collect data for quantitative studies of plant growth and development from living plants. Multi-level data, from macroscopic to molecular, and from weeks to seconds, can be acquired. Furthermore, advances in parallelized and automated image acquisition enable the throughput to capture images from large populations of plants under specific growth conditions. Image-processing capabilities allow for 3D or 4D reconstruction of image data and automated quantification of biological features. These advances facilitate the integration of imaging data with genome-wide molecular data to enable systems-level modeling. PMID:24434036

  14. Advancing weatherization performance: Measured results from the North Carolina field test of an advanced measure selection technique

    SciTech Connect

    Sharp, T.R.

    1993-07-01

    The field performance of weatherizations based on a newly-developed advanced residential energy conservation measure selection technique was tested alongside current Retro-Tech-based weatherizations in North Carolina. The two weatherization approaches were compared based on implementation ease, measures installed, labor and cost requirements, and energy savings achieved. One-hundred twenty low-income, single-family households served by three different weatherization agencies participated in the field test which was conducted between June 1989 and August 1991. Average heating energy savings were 33% for weatherizations based on the new technique and 23% for Retro-Tech-based weatherizations. Weatherizations based on the new technique achieved 43% more heating energy savings, cost around 10% less at two weatherization agencies and considerably more at the third, and were near equivalent in labor requirements. Major findings from the study include: (1) the advanced audit will install some measures in near identical quantities as Retro-Tech-based weatherizations and others in dramatically different quantities, (2) the advanced audit can significantly increase heating energy savings, (3) blower-door-directed air sealing can more than double the air leakage reductions achieved from standard air sealing techniques, (4) North Carolina low-income houses have much higher average leakage rates than similar New York houses but can be sealed as well or better, and (5) using the advanced audit will not increase weatherization costs and may actually lower costs for most weatherization agencies.

  15. CELLULAR, BIOCHEMICAL, AND MOLECULAR TECHNIQUES IN DEVELOPMENTAL TOXICOLOGY

    EPA Science Inventory

    Cellular, molecular and biochemical approaches vastly expand the possibilities for revealing the underlying mechanisms of developmental toxicity. The increasing interest in embryonic development as a model system for the study of gene expression has resulted in a cornucopia of i...

  16. Task 7: Image Enhancement and Advanced Information Extraction Techniques, 1385

    NASA Technical Reports Server (NTRS)

    Malila, W. A.; Nalepka, R. F. (principal investigators)

    1973-01-01

    The author has identified the following significant results. Atmospheric effects in satellite multispectral scanner data can influence results obtained with either manual image interpretation or computer information extraction techniques. The atmosphere attenuates radiation arriving from the surface and adds an extraneous path radiance component. Initial results of an investigation of atmospheric effects in ERTS-1 data are presented. Empirical analyses of ERTS-1 MSS data and simultaneous airborne MSS underflight data for one frame, along with theoretical calculations of atmospheric effects, are discussed. The effect of limited spatial resolution on the accuracy of information extracted from ERTS-1 data also is important. Problems occur when individual resolution elements contain two or more materials. Results from an initial application of Environmental Research Institute of Michigan techniques for estimating proportions of materials within individual elements are presented and discussed. Very accurate determination of surface areas of small lakes is achieved.

  17. Advanced techniques for target discrimination using laser speckle

    NASA Astrophysics Data System (ADS)

    Shirley, Lyle G.; Ariel, Emory D.; Hallerman, Gregory R.; Payson, Harold C.; Vivilecchia, John R.

    A new high-resolution imaging technique known as wavelength decorrelation is demonstrated in the laboratory for measuring target shape and estimating surface-scattering properties. In these demonstrations, the target is flood illuminated with a frequency-scanning Ti:sapphire ring laser. As the laser frequency changes, the speckle pattern in the backscattered light appears to boil; the time-varying intensity at a point in this pattern carries information about the target's range-resolved laser radar cross section U(z). A range resolution of better than 1 mm is demonstrated. A theoretical analysis of wavelength decorrelation is also presented, including the mathematical framework for predicting wavelength-decorrelation signatures. An additional technique known as speckle tracking is described for measuring a target's angular dynamics.

  18. Developments and advances concerning the hyperpolarisation technique SABRE.

    PubMed

    Mewis, Ryan E

    2015-10-01

    To overcome the inherent sensitivity issue in NMR and MRI, hyperpolarisation techniques are used. Signal Amplification By Reversible Exchange (SABRE) is a hyperpolarisation technique that utilises parahydrogen, a molecule that possesses a nuclear singlet state, as the source of polarisation. A metal complex is required to break the singlet order of parahydrogen and, by doing so, facilitates polarisation transfer to analyte molecules ligated to the same complex through the J-coupled network that exists. The increased signal intensities that the analyte molecules possess as a result of this process have led to investigations whereby their potential as MRI contrast agents has been probed and to understand the fundamental processes underpinning the polarisation transfer mechanism. As well as discussing literature relevant to both of these areas, the chemical structure of the complex, the physical constraints of the polarisation transfer process and the successes of implementing SABRE at low and high magnetic fields are discussed. PMID:26264565

  19. Added Value of Assessing Adnexal Masses with Advanced MRI Techniques

    PubMed Central

    Thomassin-Naggara, I.; Balvay, D.; Rockall, A.; Carette, M. F.; Ballester, M.; Darai, E.; Bazot, M.

    2015-01-01

    This review will present the added value of perfusion and diffusion MR sequences to characterize adnexal masses. These two functional MR techniques are readily available in routine clinical practice. We will describe the acquisition parameters and a method of analysis to optimize their added value compared with conventional images. We will then propose a model of interpretation that combines the anatomical and morphological information from conventional MRI sequences with the functional information provided by perfusion and diffusion weighted sequences. PMID:26413542

  20. Advanced materials and techniques for fibre-optic sensing

    NASA Astrophysics Data System (ADS)

    Henderson, Philip J.

    2014-06-01

    Fibre-optic monitoring systems came of age in about 1999 upon the emergence of the world's first significant commercialising company - a spin-out from the UK's collaborative MAST project. By using embedded fibre-optic technology, the MAST project successfully measured transient strain within high-performance composite yacht masts. Since then, applications have extended from smart composites into civil engineering, energy, military, aerospace, medicine and other sectors. Fibre-optic sensors come in various forms, and may be subject to embedment, retrofitting, and remote interrogation. The unique challenges presented by each implementation require careful scrutiny before widespread adoption can take place. Accordingly, various aspects of design and reliability are discussed spanning a range of representative technologies that include resonant microsilicon structures, MEMS, Bragg gratings, advanced forms of spectroscopy, and modern trends in nanotechnology. Keywords: Fibre-optic sensors, fibre Bragg gratings, MEMS, MOEMS, nanotechnology, plasmon.

  1. Pressure induced phase transitions studies using advanced synchrotron techniques

    NASA Astrophysics Data System (ADS)

    Liu, Haozhe; Liu, Lisa; Zhao, Jinggeng; HIT Overseas Collaborative Base at Argonne Collaboration

    2013-06-01

    In this presentation, the joint effort on high pressure research through program of Harbin Institute of Technology (HIT) Overseas Collaborative Base at Argonne will be introduced. Selected research projects on pressure induced phase transitions at room temperature and high/low temperature conditions, such as A2B3 type topological insulators, iron arsenide superconductors, piezoelectric/ferroelectric materials, ABO3 type single crystals and metallic glasses, will be presented. Recent development on imaging and diffraction tomography techniques in diamond anvil cell will be reviewed as well.

  2. Advances in dental veneers: materials, applications, and techniques

    PubMed Central

    Pini, Núbia Pavesi; Aguiar, Flávio Henrique Baggio; Lima, Débora Alves Nunes Leite; Lovadino, José Roberto; Terada, Raquel Sano Suga; Pascotto, Renata Corrêa

    2012-01-01

    Laminate veneers are a conservative treatment of unaesthetic anterior teeth. The continued development of dental ceramics offers clinicians many options for creating highly aesthetic and functional porcelain veneers. This evolution of materials, ceramics, and adhesive systems permits improvement of the aesthetic of the smile and the self-esteem of the patient. Clinicians should understand the latest ceramic materials in order to be able to recommend them and their applications and techniques, and to ensure the success of the clinical case. The current literature was reviewed to search for the most important parameters determining the long-term success, correct application, and clinical limitations of porcelain veneers. PMID:23674920

  3. Analysis techniques for coronary arteries and cardiac function using advanced MRI and CT imaging

    E-print Network

    Greenaway, Alan

    Analysis techniques for coronary arteries and cardiac function using advanced MRI and CT imaging angiography is used to assess the coronary arteries due to its high spatial resolution, and MR is used by CT feasible, while new MR techniques increase the spatial resolution imaging the coronary arteries

  4. Advanced Sonar Processing Techniques for Underwater Acoustic Multi-Input Multi-Output Communications

    E-print Network

    Evans, Brian L.

    Advanced Sonar Processing Techniques for Underwater Acoustic Multi-Input Multi sonar array processing techniques such as multichan- nel combining. In order to justify this assertion the communications as well as sonar fields; however, due to the unique propagat- ing physics of sound waves in water

  5. Advanced techniques for determining long term compatibility of materials with propellants

    NASA Technical Reports Server (NTRS)

    Green, R. L.; Stebbins, J. P.; Smith, A. W.; Pullen, K. E.

    1973-01-01

    A method for the prediction of propellant-material compatibility for periods of time up to ten years is presented. Advanced sensitive measurement techniques used in the prediction method are described. These include: neutron activation analysis, radioactive tracer technique, and atomic absorption spectroscopy with a graphite tube furnace sampler. The results of laboratory tests performed to verify the prediction method are presented.

  6. Advanced Techniques for Reservoir Simulation and Modeling of Non-Conventional Wells

    SciTech Connect

    Durlofsky, Louis J.

    2000-08-28

    This project targets the development of (1) advanced reservoir simulation techniques for modeling non-conventional wells; (2) improved techniques for computing well productivity (for use in reservoir engineering calculations) and well index (for use in simulation models), including the effects of wellbore flow; and (3) accurate approaches to account for heterogeneity in the near-well region.

  7. Biotechnology Apprenticeship for Secondary-Level Students: Teaching Advanced Cell Culture Techniques for Research

    ERIC Educational Resources Information Center

    Lewis, Jennifer R.; Kotur, Mark S.; Butt, Omar; Kulcarni, Sumant; Riley, Alyssa A.; Ferrell, Nick; Sullivan, Kathryn D.; Ferrari, Mauro

    2002-01-01

    The purpose of this article is to discuss "small-group apprenticeships (SGAs)" as a method to instruct cell culture techniques to high school participants. The study aimed to teach cell culture practices and to introduce advanced imaging techniques to solve various biomedical engineering problems. Participants designed and completed experiments…

  8. Advances in techniques for probing mechanoregulation of tissue morphogenesis.

    PubMed

    Sun, Jian; Xiao, Yuan; Wang, Shue; Slepian, Marvin J; Wong, Pak Kin

    2015-04-01

    Cells process various mechanical cues in the microenvironment to self-organize into high-order architectures during tissue morphogenesis. Impairment of morphogenic processes is the underlying cause of many diseases; as such, understanding the regulatory mechanisms associated with these processes will form the foundation for the development of innovative approaches in cell therapy and tissue engineering. Nevertheless, little is known about how cells collectively respond to mechanical cues in the microenvironment, such as global geometric guidance, local cell-cell interactions, and other physicochemical factors, for the emergence of the structural hierarchy across multiple length scales. To elucidate the mechanoregulation of tissue morphogenesis, numerous approaches based on biochemical, biomaterial, and biophysical techniques have been developed in the past decades. In this review, we summarize techniques and approaches for probing the mechanoregulation of tissue morphogenesis and illustrate their applications in vasculature development. The potential and limitations of these methods are also discussed with a view toward the investigation of a wide spectrum of tissue morphogenic processes. PMID:25331491

  9. Endoscopic therapy for early gastric cancer: Standard techniques and recent advances in ESD

    PubMed Central

    Kume, Keiichiro

    2014-01-01

    The technique of endoscopic submucosal dissection (ESD) is now a well-known endoscopic therapy for early gastric cancer. ESD was introduced to resect large specimens of early gastric cancer in a single piece. ESD can provide precision of histologic diagnosis and can also reduce the recurrence rate. However, the drawback of ESD is its technical difficulty, and, consequently, it is associated with a high rate of complications, the need for advanced endoscopic techniques, and a lengthy procedure time. Various advances in the devices and techniques used for ESD have contributed to overcoming these drawbacks. PMID:24914364

  10. Endoscopic therapy for early gastric cancer: standard techniques and recent advances in ESD.

    PubMed

    Kume, Keiichiro

    2014-06-01

    The technique of endoscopic submucosal dissection (ESD) is now a well-known endoscopic therapy for early gastric cancer. ESD was introduced to resect large specimens of early gastric cancer in a single piece. ESD can provide precision of histologic diagnosis and can also reduce the recurrence rate. However, the drawback of ESD is its technical difficulty, and, consequently, it is associated with a high rate of complications, the need for advanced endoscopic techniques, and a lengthy procedure time. Various advances in the devices and techniques used for ESD have contributed to overcoming these drawbacks. PMID:24914364

  11. Molecular alignment and orientation with a hybrid Raman scattering technique

    NASA Astrophysics Data System (ADS)

    Bustard, Philip J.; Lausten, R.; Sussman, Benjamin J.

    2012-11-01

    We demonstrate a scheme for the preparation of molecular alignment and angular momentum orientation using a hybrid combination of two limits of Raman scattering. First a weak, impulsive pump pulse initializes the system via the nonresonant dynamic Stark effect. Then, having overcome the influence of the vacuum fluctuations, an amplification pulse selectively enhances the initial coherences by transient stimulated Raman scattering, generating alignment and angular momentum orientation of molecular hydrogen. The amplitude and phase of the resulting coherent dynamics are experimentally probed, indicating an amplification factor of 4.5. An analytic theory is developed to model the dynamics.

  12. Recent advances in yeast molecular biology: recombinant DNA. [Lead abstract

    SciTech Connect

    Not Available

    1982-09-01

    Separate abstracts were prepared for the 25 papers presented at a workshop focusing on chromosomal structure, gene regulation, recombination, DNA repair, and cell type control, that have been obtained by experimental approaches incorporating the new technologies of yeast DNA transformation, molecular cloning, and DNA sequence analysis. (KRM)

  13. The Role of XAFS in Advancing the Frontiers of Molecular

    E-print Network

    Sparks, Donald L.

    . Hallock du Pont Chair of Soil and Environmental Chemistry Spectroscopy/Microscopy 4th PSI Summer School information on the molecular aspects and interactions of a compounds No direct electronic information Magnetic activated by perturbation Electronic spectroscopies UV, VIS, luminecent Oxidation state and limited

  14. Molecular Techniques and Links (Manish Raizada, University of Guelph)

    E-print Network

    Raizada, Manish N.

    ://www.bio.davidson.edu/courses/genomics/chip/chip.html Wikipedia, microarrays http://en.wikipedia.org/wiki/DNA_microarray Excellent Microarray Tutorial http://www.bioteach.ubc.ca/MolecularBiology/microarray how regulated) c. Analyze how gene is expressed in online microarray profiles d. Evolutionary Microarrays (mutant vs wild-type; overxpression vs wild-type) (whole procedure and analysis, 6mos) a

  15. The Use of Molecular Techniques at Hazardous Waste Sites

    EPA Science Inventory

    It is clear that typical protocols used for soil analysis would certainly fail to adequately interrogate ground-water treatment systems unless they were substantially modified. The modifications found necessary to compensate for the low biomass include molecular tools and techniq...

  16. Analysis of leading edge and trailing edge cover glass samples before and after treatment with advanced satellite contamination removal techniques

    NASA Technical Reports Server (NTRS)

    Hotaling, S. P.

    1993-01-01

    Two samples from Long Duration Exposure Facility (LDEF) experiment M0003-4 were analyzed for molecular and particulate contamination prior to and following treatment with advanced satellite contamination removal techniques (CO2 gas/solid jet spray and oxygen ion beam). The pre- and post-cleaning measurements and analyses are presented. The jet spray removed particulates in seconds. The low energy reactive oxygen ion beam removed 5,000 A of photo polymerized organic hydrocarbon contamination in less than 1 hour. Spectroscopic analytical techniques were applied to the analysis of cleaning efficiency including: Fourier transform infrared, Auger, x ray photoemissions, energy dispersive x ray, and ultraviolet/visible. The results of this work suggest that the contamination studied here was due to spacecraft self-contamination enhanced by atomic oxygen plasma dynamics and solar UV radiation. These results also suggest the efficacy for the jet spray and ion beam contamination control technologies for spacecraft optical surfaces.

  17. Molecular imaging with optics: primer and case for near-infrared fluorescence techniques in personalized medicine

    PubMed Central

    Sevick-Muraca, Eva M.; Rasmussen, John C.

    2010-01-01

    We compare and contrast the development of optical molecular imaging techniques with nuclear medicine with a didactic emphasis for initiating readers into the field of molecular imaging. The nuclear imaging techniques of gamma scintigraphy, single-photon emission computed tomography, and positron emission tomography are first briefly reviewed. The molecular optical imaging techniques of bioluminescence and fluorescence using gene reporter/probes and gene reporters are described prior to introducing the governing factors of autofluorescence and excitation light leakage. The use of dual-labeled, near-infrared excitable and radio-labeled agents are described with comparative measurements between planar fluorescence and nuclear molecular imaging. The concept of time-independent and -dependent measurements is described with emphasis on integrating time-dependent measurements made in the frequency domain for 3-D tomography. Finally, we comment on the challenges and progress for translating near-infrared (NIR) molecular imaging agents for personalized medicine. PMID:19021311

  18. Advances in Current Rating Techniques for Flexible Printed Circuits

    NASA Technical Reports Server (NTRS)

    Hayes, Ron

    2014-01-01

    Twist Capsule Assemblies are power transfer devices commonly used in spacecraft mechanisms that require electrical signals to be passed across a rotating interface. Flexible printed circuits (flex tapes, see Figure 2) are used to carry the electrical signals in these devices. Determining the current rating for a given trace (conductor) size can be challenging. Because of the thermal conditions present in this environment the most appropriate approach is to assume that the only means by which heat is removed from the trace is thru the conductor itself, so that when the flex tape is long the temperature rise in the trace can be extreme. While this technique represents a worst-case thermal situation that yields conservative current ratings, this conservatism may lead to overly cautious designs when not all traces are used at their full rated capacity. A better understanding of how individual traces behave when they are not all in use is the goal of this research. In the testing done in support of this paper, a representative flex tape used for a flight Solar Array Drive Assembly (SADA) application was tested by energizing individual traces (conductors in the tape) in a vacuum chamber and the temperatures of the tape measured using both fine-gauge thermocouples and infrared thermographic imaging. We find that traditional derating schemes used for bundles of wires do not apply for the configuration tested. We also determine that single active traces located in the center of a flex tape operate at lower temperatures than those on the outside edges.

  19. Advances in Reverberation Mapping of Quasars: Techniques, Experiments, and Implications

    NASA Astrophysics Data System (ADS)

    Denney, Kelly

    2014-01-01

    Reverberation mapping is the only method capable of directly measuring the mass of supermassive black holes in galaxies outside the local universe. In addition, it has the potential to act as a cosmological distance probe to sources spanning 0 < z &;lt; 4. This method is applicable to broad line active galaxies, or quasars, by taking advantage of the light travel time delay between variability signals observed from the central black hole accretion disk continuum emission and from the photoionized line-emitting gas in the vicinity of the central source. This shifts the observational requirements from spatial dependence to temporal dependence in order to resolve the central structure. So far, reverberation mapping experiments have primarily been carried out locally (z < 0.3), but I will discuss how several new experiments are targeting more distant sources and/or using more time efficient methods to apply this technique to quasars with a broader range of observed spectral characteristics and across cosmological scales. I will also discuss how the resulting measurements have the potential to impact our understanding of cosmology and dark energy.

  20. Recent advances in the molecular design of synthetic vaccines.

    PubMed

    Jones, Lyn H

    2015-11-20

    Vaccines have typically been prepared using whole organisms. These are normally either attenuated bacteria or viruses that are live but have been altered to reduce their virulence, or pathogens that have been inactivated and effectively killed through exposure to heat or formaldehyde. However, using whole organisms to elicit an immune response introduces the potential for infections arising from a reversion to a virulent form in live pathogens, unproductive reactions to vaccine components or batch-to-batch variability. Synthetic vaccines, in which a molecular antigen is conjugated to a carrier protein, offer the opportunity to circumvent these problems. This Perspective will highlight the progress that has been achieved in developing synthetic vaccines using a variety of molecular antigens. In particular, the different approaches used to develop conjugate vaccines using peptide/proteins, carbohydrates and other small molecule haptens as antigens are compared. PMID:26587710

  1. Using "Pseudomonas Putida xylE" Gene to Teach Molecular Cloning Techniques for Undergraduates

    ERIC Educational Resources Information Center

    Dong, Xu; Xin, Yi; Ye, Li; Ma, Yufang

    2009-01-01

    We have developed and implemented a serial experiment in molecular cloning laboratory course for undergraduate students majored in biotechnology. "Pseudomonas putida xylE" gene, encoding catechol 2, 3-dioxygenase, was manipulated to learn molecular biology techniques. The integration of cloning, expression, and enzyme assay gave students a chance…

  2. An icing physics study by using lifetime-based molecular tagging thermometry technique

    E-print Network

    Hu, Hui

    of the cleanest renewable power sources in the world today. The US Department of Energy has challenged the nationAn icing physics study by using lifetime-based molecular tagging thermometry technique Hui Hu 12 April 2010 Available online 18 April 2010 Keywords: Molecular tagging thermometry Icing physics

  3. Advanced Photoresist Technologies by Intricate Molecular Brush Architectures 

    E-print Network

    Cho, Sangho

    2015-08-07

    HS for use as the reactive majority of the molecular brush structures, we turned to RAFT copolymerization, as the free-radical copolymerizations of pHS with methacrylates have recently been reported.94 From the viewpoint of the comonomer pair, N...-substituted maleimides were more effective candidates than methacrylates for RAFT copolymerization with pHS because of their well-documented low tendency to homopolymerize when undergoing significant cross-propagation with styrenic comonomers.95,96 RAFT...

  4. A Novel Microcharacterization Technique in the Measurement of Strain and Orientation Gradient in Advanced Materials

    NASA Technical Reports Server (NTRS)

    Garmestai, H.; Harris, K.; Lourenco, L.

    1997-01-01

    Representation of morphology and evolution of the microstructure during processing and their relation to properties requires proper experimental techniques. Residual strains, lattice distortion, and texture (micro-texture) at the interface and the matrix of a layered structure or a functionally gradient material and their variation are among parameters important in materials characterization but hard to measure with present experimental techniques. Current techniques available to measure changes in interred material parameters (residual stress, micro-texture, microplasticity) produce results which are either qualitative or unreliable. This problem becomes even more complicated in the case of a temperature variation. These parameters affect many of the mechanical properties of advanced materials including stress-strain relation, ductility, creep, and fatigue. A review of some novel experimental techniques using recent advances in electron microscopy is presented here to measure internal stress, (micro)texture, interracial strength and (sub)grain formation and realignment. Two of these techniques are combined in the chamber of an Environmental Scanning Electron Microscope to measure strain and orientation gradients in advanced materials. These techniques which include Backscattered Kikuchi Diffractometry (BKD) and Microscopic Strain Field Analysis are used to characterize metallic and intermetallic matrix composites and superplastic materials. These techniques are compared with the more conventional x-ray diffraction and indentation techniques.

  5. Biomarkers and Molecular Imaging as Predictors of Response to Neoadjuvant Chemoradiotherapy in Patients With Locally Advanced Rectal Cancer.

    PubMed

    Molinari, Chiara; Matteucci, Federica; Caroli, Paola; Passardi, Alessandro

    2015-12-01

    Standard treatment of patients with locally advanced rectal cancer (LARC) includes neoadjuvant chemoradiotherapy (NCRT) followed by surgery. Tumor regression after NCRT varies substantially among individuals and pathological complete response is a known prognostic factor for LARC. The identification of a predictive model for response to chemoradiotherapy would help clinicians to identify patients who would probably benefit from multimodal treatment and to perform an early assessment of individual prognosis. Carcinoembryonic antigen has proven to be a good predictor of response in several clinical trials. Other widely studied predictive models in LARC include molecular biomarkers, analyzed at various levels and by different techniques, and molecular imaging, in particular magnetic resonance imaging and positron emission tomography/computed tomography. Although none of the studied markers have been approved in clinical practice, their evaluation in larger, prospective trials and in combined predictive models could be of use to define tailored therapeutic strategies. PMID:26170142

  6. Advances in high-resolution imaging – techniques for three-dimensional imaging of cellular structures

    PubMed Central

    Lidke, Diane S.; Lidke, Keith A.

    2012-01-01

    A fundamental goal in biology is to determine how cellular organization is coupled to function. To achieve this goal, a better understanding of organelle composition and structure is needed. Although visualization of cellular organelles using fluorescence or electron microscopy (EM) has become a common tool for the cell biologist, recent advances are providing a clearer picture of the cell than ever before. In particular, advanced light-microscopy techniques are achieving resolutions below the diffraction limit and EM tomography provides high-resolution three-dimensional (3D) images of cellular structures. The ability to perform both fluorescence and electron microscopy on the same sample (correlative light and electron microscopy, CLEM) makes it possible to identify where a fluorescently labeled protein is located with respect to organelle structures visualized by EM. Here, we review the current state of the art in 3D biological imaging techniques with a focus on recent advances in electron microscopy and fluorescence super-resolution techniques. PMID:22685332

  7. Techniques in molecular spectroscopy: from broad bandwidth to high resolution

    E-print Network

    Jin, Deborah

    and enable new applications. The new technique of cavity-enhanced di- rect frequency comb spectroscopy (CE. There are sev- eral key requirements for CE-DFCS: a frequency comb source that provides broad bandwidth and high on the coherence properties of spectral broadening in nonlinear fiber and the development of a high-power frequency

  8. Biochemistry and Molecular Biology Techniques for Person Characterization

    ERIC Educational Resources Information Center

    Herrero, Salvador; Ivorra, Jose Luis; Garcia-Sogo, Magdalena; Martinez-Cortina, Carmen

    2008-01-01

    Using the traditional serological tests and the most novel techniques for DNA fingerprinting, forensic scientists scan different traits that vary from person to person and use the data to include or exclude suspects based on matching with the evidence obtained in a criminal case. Although the forensic application of these methods is well known,…

  9. Pushing CT and MR Imaging to the Molecular Level for Studying the “Omics”: Current Challenges and Advancements

    PubMed Central

    Huang, Hsuan-Ming; Shih, Yi-Yu

    2014-01-01

    During the past decade, medical imaging has made the transition from anatomical imaging to functional and even molecular imaging. Such transition provides a great opportunity to begin the integration of imaging data and various levels of biological data. In particular, the integration of imaging data and multiomics data such as genomics, metabolomics, proteomics, and pharmacogenomics may open new avenues for predictive, preventive, and personalized medicine. However, to promote imaging-omics integration, the practical challenge of imaging techniques should be addressed. In this paper, we describe key challenges in two imaging techniques: computed tomography (CT) and magnetic resonance imaging (MRI) and then review existing technological advancements. Despite the fact that CT and MRI have different principles of image formation, both imaging techniques can provide high-resolution anatomical images while playing a more and more important role in providing molecular information. Such imaging techniques that enable single modality to image both the detailed anatomy and function of tissues and organs of the body will be beneficial in the imaging-omics field. PMID:24738056

  10. POC-Scale Testing of an Advanced Fine Coal Dewatering Equipment/Technique

    SciTech Connect

    B. K. Karekh; D. Tao; J. G. Groppo

    1998-08-28

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 mm) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20% level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy's program to show that ultra-clean coal could be effectively dewatered to 20% or lower moisture using either conventional or advanced dewatering techniques. The cost-sharing contract effort is for 45 months beginning September 30, 1994. This report discusses technical progress made during the quarter from January 1 ? March 31, 1998.

  11. MO-C-BRE-01: The WMIS-AAPM Joint Symposium: Advances in Molecular Imaging

    SciTech Connect

    Contag, C; Pogue, B; Lewis, J

    2014-06-15

    This joint symposium of the World Molecular Imaging Society (WMIS) and the AAPM includes three luminary speakers discussing work in new paradigms of molecular imaging in cancer (Contag), applications of optical imaging technologies to radiation therapy (Pogue) and an update on PET imaging as a surrogate biomarker for cancer progression and response to therapy. Learning Objectives: Appreciate the current trends in molecular and systems imaging. Understand how optical imaging technologies, and particularly Cerenkov detectors, can be used in advancing radiation oncology. Stay current on new PET tracers - and targets - of interest in cancer treatment.

  12. Clinical management of advanced gastric cancer: The role of new molecular drugs

    PubMed Central

    De Vita, Ferdinando; Di Martino, Natale; Fabozzi, Alessio; Laterza, Maria Maddalena; Ventriglia, Jole; Savastano, Beatrice; Petrillo, Angelica; Gambardella, Valentina; Sforza, Vincenzo; Marano, Luigi; Auricchio, Annamaria; Galizia, Gennaro; Ciardiello, Fortunato; Orditura, Michele

    2014-01-01

    Gastric cancer is the fourth most common malignant neoplasm and the second leading cause of death for cancer in Western countries with more than 20000 new cases yearly diagnosed in the United States. Surgery represents the main approach for this disease but, notwithstanding the advances in surgical techniques, we observed a minimal improvement in terms of overall survival with a significant increasing of relapsing disease rates. Despite the development of new drugs has significantly improved the effectiveness of chemotherapy, the prognosis of patients with unresectable or metastatic gastric adenocarcinoma remains poor. Recently, several molecular target agents have been investigated; in particular, trastuzumab represents the first target molecule showing improvements in overall survival in human epithelial growth factor 2-positive gastric cancer patients. New molecules targeting vascular epithelial growth factor, mammalian target of rapamycin, and anti hepatocyte growth factor-c-Met pathway are also under investigation, with interesting results. Anyway, it seems necessary to select more accurately the population to treat with new agents by the identification of new biomarkers in order to optimize the results. In this paper we review the actual “scenario” of targeted treatments, also focusing on the new agents in development for gastric cancer and gastro-esophageal carcinoma, discussing their efficacy and potential applications in clinical practice. PMID:25356019

  13. Reflection mass spectrometry technique for monitoring and controlling composition during molecular beam epitaxy

    DOEpatents

    Brennan, Thomas M. (Albuquerque, NM); Hammons, B. Eugene (Tijeras, NM); Tsao, Jeffrey Y. (Albuquerque, NM)

    1992-01-01

    A method for on-line accurate monitoring and precise control of molecular beam epitaxial growth of Groups III-III-V or Groups III-V-V layers in an advanced semiconductor device incorporates reflection mass spectrometry. The reflection mass spectrometry is responsive to intentional perturbations in molecular fluxes incident on a substrate by accurately measuring the molecular fluxes reflected from the substrate. The reflected flux is extremely sensitive to the state of the growing surface and the measurements obtained enable control of newly forming surfaces that are dynamically changing as a result of growth.

  14. Reflection mass spectrometry technique for monitoring and controlling composition during molecular beam epitaxy

    DOEpatents

    Brennan, T.M.; Hammons, B.E.; Tsao, J.Y.

    1992-12-15

    A method for on-line accurate monitoring and precise control of molecular beam epitaxial growth of Groups III-III-V or Groups III-V-V layers in an advanced semiconductor device incorporates reflection mass spectrometry. The reflection mass spectrometry is responsive to intentional perturbations in molecular fluxes incident on a substrate by accurately measuring the molecular fluxes reflected from the substrate. The reflected flux is extremely sensitive to the state of the growing surface and the measurements obtained enable control of newly forming surfaces that are dynamically changing as a result of growth. 3 figs.

  15. Quantum and Molecular Mechanical (QM/MM) Monte Carlo Techniques for Modeling Condensed-Phase Reactions

    PubMed Central

    Jorgensen, Wiliiam L.

    2014-01-01

    A recent review (Acc. Chem. Res. 2010, 43:142–151) examined our use and development of a combined quantum and molecular mechanical (QM/MM) technique for modelling organic and enzymatic reactions. Advances included the PDDG/PM3 semiempirical QM (SQM) method, computation of multi-dimensional potentials of mean force (PMF), incorporation of on-the-fly QM in Monte Carlo simulations, and a polynomial quadrature method for rapidly treating proton-transfer reactions. The current article serves as a follow up on our progress. Highlights include new reactions, alternative SQM methods, a polarizable OPLS force field, and novel solvent environments, e.g., “on water” and room temperature ionic liquids. The methodology is strikingly accurate across a wide range of condensed-phase and antibody-catalyzed reactions including substitution, decarboxylation, elimination, isomerization, and pericyclic classes. Comparisons are made to systems treated with continuum-based solvents and ab initio or density functional theory (DFT) methods. Overall, the QM/MM methodology provides detailed characterization of reaction paths, proper configurational sampling, several advantages over implicit solvent models, and a reasonable computational cost. PMID:25431625

  16. Recent advances in methamphetamine neurotoxicity mechanisms and its molecular pathophysiology.

    PubMed

    Yu, Shaobin; Zhu, Ling; Shen, Qiang; Bai, Xue; Di, Xuhui

    2015-01-01

    Methamphetamine (METH) is a sympathomimetic amine that belongs to phenethylamine and amphetamine class of psychoactive drugs, which are widely abused for their stimulant, euphoric, empathogenic, and hallucinogenic properties. Many of these effects result from acute increases in dopamine and serotonin neurotransmission. Subsequent to these acute effects, METH produces persistent damage to dopamine and serotonin release in nerve terminals, gliosis, and apoptosis. This review summarized the numerous interdependent mechanisms including excessive dopamine, ubiquitin-proteasome system dysfunction, protein nitration, endoplasmic reticulum stress, p53 expression, inflammatory molecular, D3 receptor, microtubule deacetylation, and HIV-1 Tat protein that have been demonstrated to contribute to this damage. In addition, the feasible therapeutic strategies according to recent studies were also summarized ranging from drug and protein to gene level. PMID:25861156

  17. Recent Advances in Methamphetamine Neurotoxicity Mechanisms and Its Molecular Pathophysiology

    PubMed Central

    Yu, Shaobin; Zhu, Ling; Shen, Qiang; Bai, Xue; Di, Xuhui

    2015-01-01

    Methamphetamine (METH) is a sympathomimetic amine that belongs to phenethylamine and amphetamine class of psychoactive drugs, which are widely abused for their stimulant, euphoric, empathogenic, and hallucinogenic properties. Many of these effects result from acute increases in dopamine and serotonin neurotransmission. Subsequent to these acute effects, METH produces persistent damage to dopamine and serotonin release in nerve terminals, gliosis, and apoptosis. This review summarized the numerous interdependent mechanisms including excessive dopamine, ubiquitin-proteasome system dysfunction, protein nitration, endoplasmic reticulum stress, p53 expression, inflammatory molecular, D3 receptor, microtubule deacetylation, and HIV-1 Tat protein that have been demonstrated to contribute to this damage. In addition, the feasible therapeutic strategies according to recent studies were also summarized ranging from drug and protein to gene level. PMID:25861156

  18. Polymicrobial chronic endophthalmitis diagnosed by culture and molecular technique.

    PubMed

    Mukherjee, A; Pramanik, S; Das, D; Roy, R; Therese, K L

    2014-01-01

    Accurate etiological diagnosis is the key to prevention of ocular morbidity in endophthalmitis cases. A 66 year old male was suffering from chronic endophthalmitis post-cataract surgery. Polymerase chain reaction examination on anterior chamber fluid was positive for Propionibacterium acnes but negative for the panfungal genome. He was advised vitrectomy with intravitreal injections. Polymerase chain reaction of vitreous aspirate was positive for P.acnes as well as panfungal genome. The vitreous sample also grew yeast in culture which was identified as Candida pseudotropicalis. Patient was treated on an alternate day regimen of intravitreal Vancomycin and Amphotericin B in the post-operative period. There was improvement in vision at final follow up. Chronic endophthalmitis can have polymicrobial etiology which will require appropriate diagnostic and therapeutic strategies. The role of molecular testing is vital in these cases as growth in culture is often negative. PMID:25008833

  19. Modulation/demodulation techniques for satellite communications. Part 2: Advanced techniques. The linear channel

    NASA Technical Reports Server (NTRS)

    Omura, J. K.; Simon, M. K.

    1982-01-01

    A theory is presented for deducing and predicting the performance of transmitter/receivers for bandwidth efficient modulations suitable for use on the linear satellite channel. The underlying principle used is the development of receiver structures based on the maximum-likelihood decision rule. The application of the performance prediction tools, e.g., channel cutoff rate and bit error probability transfer function bounds to these modulation/demodulation techniques.

  20. 2010NatureAmerica,Inc.Allrightsreserved. NATURE STRUCTURAL & MOLECULAR BIOLOGY ADVANCE ONLINE PUBLICATION 1

    E-print Network

    Ahringe, Julie

    ©2010NatureAmerica,Inc.Allrightsreserved. NATURE STRUCTURAL & MOLECULAR BIOLOGY ADVANCE ONLINE- tion of the DNA-RNA-protein `Central Dogma', came strong experi- mental evidence that histones with biological func- tions3. However, the reproducibility and biological relevance of histone

  1. Advances in understanding the molecular basis of the first steps in color vision

    E-print Network

    Palczewski, Krzysztof

    pigments Spectral tuning Energetics Color blindness Vision Retina a b s t r a c t Serving as one of our color blinding mutations impair secondary structural elements of these G protein-coupled receptorsAdvances in understanding the molecular basis of the first steps in color vision Lukas Hofmann

  2. Clinical applications of recent molecular advances in urologic malignancies: no longer chasing a "mirage"?

    PubMed

    Netto, George J

    2013-05-01

    As our understanding of the molecular events leading to the development and progression of genitourologic malignancies, new markers of detection, prognostication, and therapy prediction can be exploited in the management of these prevalent tumors. The current review discusses the recent advances in prostate, bladder, renal, and testicular neoplasms that are pertinent to the anatomic pathologist. PMID:23574774

  3. 2011NatureAmerica,Inc.Allrightsreserved. nature structural & molecular biology advance online publication

    E-print Network

    Washington at Seattle, University of

    ©2011NatureAmerica,Inc.Allrightsreserved. nature structural & molecular biology advance online experiment in protein structure predic- tion methods in which the amino acid sequences of structures that the CASP organizers did not indicate as oligomeric. For targets with homologs of known structure

  4. Multifunctional nanomaterials for advanced molecular imaging and cancer therapy

    NASA Astrophysics Data System (ADS)

    Subramaniam, Prasad

    Nanotechnology offers tremendous potential for use in biomedical applications, including cancer and stem cell imaging, disease diagnosis and drug delivery. The development of nanosystems has aided in understanding the molecular mechanisms of many diseases and permitted the controlled nanoscale manipulation of biological phenomena. In recent years, many studies have focused on the use of several kinds of nanomaterials for cancer and stem cell imaging and also for the delivery of anticancer therapeutics to tumor cells. However, the proper diagnosis and treatment of aggressive tumors such as brain and breast cancer requires highly sensitive diagnostic agents, in addition to the ability to deliver multiple therapeutics using a single platform to the target cells. Addressing these challenges, novel multifunctional nanomaterial-based platforms that incorporate multiple therapeutic and diagnostic agents, with superior molecular imaging and targeting capabilities, has been presented in this work. The initial part of this work presents the development of novel nanomaterials with superior optical properties for efficiently delivering soluble cues such as small interfering RNA (siRNA) into brain cancer cells with minimal toxicity. Specifically, this section details the development of non-toxic quantums dots for the imaging and delivery of siRNA into brain cancer and mesenchymal stem cells, with the hope of using these quantum dots as multiplexed imaging and delivery vehicles. The use of these quantum dots could overcome the toxicity issues associated with the use of conventional quantum dots, enabled the imaging of brain cancer and stem cells with high efficiency and allowed for the delivery of siRNA to knockdown the target oncogene in brain cancer cells. The latter part of this thesis details the development of nanomaterial-based drug delivery platforms for the co-delivery of multiple anticancer drugs to brain tumor cells. In particular, this part of the thesis focuses on the synthesis and use of a biodegradable dendritic polypeptide-based nanocarrier for the delivery of multiple anticancer drugs and siRNA to brain tumor cells. The co-delivery of important anticancer agents using a single platform was shown to increase the efficacy of the drugs manyfold, ensuring the cancer cell-specific delivery and minimizing dose limiting toxicities of the individual drugs. This would be of immense importance when used in vivo.

  5. Modulation/demodulation techniques for satellite communications. Part 3: Advanced techniques. The nonlinear channel

    NASA Technical Reports Server (NTRS)

    Omura, J. K.; Simon, M. K.

    1982-01-01

    A theory for deducing and predicting the performance of transmitter/receivers for bandwidth efficient modulations suitable for use on the nonlinear satellite channel is presented. The underlying principle used throughout is the development of receiver structures based on the maximum likelihood decision rule and aproximations to it. The bit error probability transfer function bounds developed in great detail in Part 4 is applied to these modulation/demodulation techniques. The effects of the various degrees of receiver mismatch are considered both theoretically and by numerous illustrative examples.

  6. Advances in the Molecular Genetics of Non-syndromic Syndactyly

    PubMed Central

    Deng, Hao; Tan, Ting

    2015-01-01

    Syndactyly, webbing of adjacent digits with or without bony fusion, is one of the most common hereditary limb malformations. It occurs either as an isolated abnormality or as a component of more than 300 syndromic anomalies. There are currently nine types of phenotypically diverse nonsyndromic syndactyly. Non-syndromic syndactyly is usually inherited as an autosomal dominant trait, although the more severe presenting types and subtypes may show autosomal recessive or X-linked pattern of inheritance. The phenotype appears to be not only caused by a main gene, but also dependant on genetic background and subsequent signaling pathways involved in limb formation. So far, the principal genes identified to be involved in congenital syndactyly are mainly involved in the zone of polarizing activity and sonic hedgehog pathway. This review summarizes the recent progress made in the molecular genetics, including known genes and loci responsible for non-syndromic syndactyly, and the signaling pathways those genetic factors involved in, as well as clinical features and animal models. We hope our review will contribute to the understanding of underlying pathogenesis of this complicated disorder and have implication on genetic counseling. PMID:26069458

  7. Advanced Molecular Probes for Sequence-Specific DNA Recognition

    NASA Astrophysics Data System (ADS)

    Bertucci, Alessandro; Manicardi, Alex; Corradini, Roberto

    DNA detection can be achieved using the Watson-Crick base pairing with oligonucleotides or oligonucleotide analogs, followed by generation of a physical or chemical signal coupled with a transducer device. The nature of the probe is an essential feature which determines the performances of the sensing device. Many synthetic processes are presently available for "molecular engineering" of DNA probes, enabling label-free and PCR-free detection to be performed. Furthermore, many DNA analogs with improved performances are available and are under development; locked nucleic acids (LNA), peptide nucleic acids (PNA) and their analogs, morpholino oligonucleotides (MO) and other modified probes have shown improved properties of affinity and selectivity in target recognition compared to those of simple DNA probes. The performances of these probes in sensing devices, and the requirements for detection of unamplified DNA will be discussed in this chapter. Chemistry and architectures for conjugation of probes to reporter units, surfaces and nanostructures will also be discussed. Examples of probes used in ultrasensitive detection of unamplified DNA are listed.

  8. Recent advances toward a molecular mechanism of efflux pump inhibition

    PubMed Central

    Opperman, Timothy J.; Nguyen, Son T.

    2015-01-01

    Multidrug resistance (MDR) in Gram-negative pathogens, such as the Enterobacteriaceae and Pseudomonas aeruginosa, poses a significant threat to our ability to effectively treat infections caused by these organisms. A major component in the development of the MDR phenotype in Gram-negative bacteria is overexpression of Resistance-Nodulation-Division (RND)-type efflux pumps, which actively pump antibacterial agents and biocides from the periplasm to the outside of the cell. Consequently, bacterial efflux pumps are an important target for developing novel antibacterial treatments. Potent efflux pump inhibitors (EPIs) could be used as adjunctive therapies that would increase the potency of existing antibiotics and decrease the emergence of MDR bacteria. Several potent inhibitors of RND-type efflux pump have been reported in the literature, and at least three of these EPI series were optimized in a pre-clinical development program. However, none of these compounds have been tested in the clinic. One of the major hurdles to the development of EPIs has been the lack of biochemical, computational, and structural methods that could be used to guide rational drug design. Here, we review recent reports that have advanced our understanding of the mechanism of action of several potent EPIs against RND-type pumps. PMID:25999939

  9. Molecular advances in autosomal dominant polycystic kidney disease.

    PubMed

    Gallagher, Anna Rachel; Germino, Gregory G; Somlo, Stefan

    2010-03-01

    Autosomal dominant polycystic disease (ADPKD) is the most common form of inherited kidney disease that results in renal failure. The understanding of the pathogenesis of ADPKD has advanced significantly since the discovery of the 2 causative genes, PKD1 and PKD2. Dominantly inherited gene mutations followed by somatic second-hit mutations inactivating the normal copy of the respective gene result in renal tubular cyst formation that deforms the kidney and eventually impairs its function. The respective gene products, polycystin-1 and polycystin-2, work together in a common cellular pathway. Polycystin-1, a large receptor molecule, forms a receptor-channel complex with polycystin-2, which is a cation channel belonging to the TRP family. Both polycystin proteins have been localized to the primary cilium, a nonmotile microtubule-based structure that extends from the apical membrane of tubular cells into the lumen. Here we discuss recent insights in the pathogenesis of ADPKD including the genetics of ADPKD, the properties of the respective polycystin proteins, the role of cilia, and some cell-signaling pathways that have been implicated in the pathways related to PKD1 and PKD2. PMID:20219615

  10. Progress of Molecular Targeted Therapies for Advanced Renal Cell Carcinoma

    PubMed Central

    Santoni, Matteo; Amantini, Consuelo; Burattini, Luciano; Berardi, Rossana; Santoni, Giorgio; Cascinu, Stefano; Muzzonigro, Giovanni

    2013-01-01

    Vascular endothelial growth factor (VEGF) plays a crucial role in tumor angiogenesis. VEGF expression in metastatic renal cell carcinoma (mRCC) is mostly regulated by hypoxia, predominantly via the hypoxia-induced factor (HIF)/Von Hippel-Lindau (VHL) pathway. Advances in our knowledge of VEGF role in tumor angiogenesis, growth, and progression have permitted development of new approaches for the treatment of mRCC, including several agents targeting VEGF and VEGF receptors: tyrosine kinase pathway, serine/threonine kinases, ?5?1-integrin, deacetylase, CD70, mammalian target of rapamycin (mTOR), AKT, and phosphatidylinositol 3?-kinase (PI3K). Starting from sorafenib and sunitinib, several targeted therapies have been approved for mRCC treatment, with a long list of agents in course of evaluation, such as tivozanib, cediranib, and VEGF-Trap. Here we illustrate the main steps of tumor angiogenesis process, defining the pertinent therapeutic targets and the efficacy and toxicity profiles of these new promising agents. PMID:24093097

  11. Detecting Molecular Properties by Various Laser-Based Techniques

    SciTech Connect

    Tse-Ming Hsin

    2007-08-03

    Four different laser-based techniques were applied to study physical and chemical characteristics of biomolecules and dye molecules. These techniques are liole burning spectroscopy, single molecule spectroscopy, time-resolved coherent anti-Stokes Raman spectroscopy and laser-induced fluorescence microscopy. Results from hole burning and single molecule spectroscopy suggested that two antenna states (C708 & C714) of photosystem I from cyanobacterium Synechocystis PCC 6803 are connected by effective energy transfer and the corresponding energy transfer time is {approx}6 ps. In addition, results from hole burning spectroscopy indicated that the chlorophyll dimer of the C714 state has a large distribution of the dimer geometry. Direct observation of vibrational peaks and evolution of coumarin 153 in the electronic excited state was demonstrated by using the fs/ps CARS, a variation of time-resolved coherent anti-Stokes Raman spectroscopy. In three different solvents, methanol, acetonitrile, and butanol, a vibration peak related to the stretch of the carbonyl group exhibits different relaxation dynamics. Laser-induced fluorescence microscopy, along with the biomimetic containers-liposomes, allows the measurement of the enzymatic activity of individual alkaline phosphatase from bovine intestinal mucosa without potential interferences from glass surfaces. The result showed a wide distribution of the enzyme reactivity. Protein structural variation is one of the major reasons that are responsible for this highly heterogeneous behavior.

  12. CodingisCoolLevel2 More Advanced Techniques in Computer Science

    E-print Network

    Barrash, Warren

    to create visual sketches · Using Processing to control Finch robots · One day of guided coding usingCodingisCool­Level2 More Advanced Techniques in Computer Science A Workshop for High School Students in Grades 11th-12th This two-day workshop introduces computer science principles using

  13. 75 FR 81643 - In the Matter of Certain Semiconductor Products Made by Advanced Lithography Techniques and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-28

    ... certain claims of U.S. Patent No. 6,042,998. 75 FR. 44,015 (July 27, 2010). The complaint named two... In the Matter of Certain Semiconductor Products Made by Advanced Lithography Techniques and Products... for ] importation, and sale within the United States after importation of certain...

  14. ADVANCED TEM TECHNIQUES FOR ASSESSING THE POSSIBLE BIOGENIC ORIGIN OF METEORITIC MAGNETITE CRYSTALS. M. Weyland

    E-print Network

    Dunin-Borkowski, Rafal E.

    ADVANCED TEM TECHNIQUES FOR ASSESSING THE POSSIBLE BIOGENIC ORIGIN OF METEORITIC MAGNETITE CRYSTALS of extraterrestrial life is provided by a small subset of magnetite (Fe3O4) crystals found in meteorite ALH84001 from bacteria [1, 2]. The conclusion that the meteoritic crystals are `physically and chemi- cally identical

  15. Real-time application of advanced three-dimensional graphic techniques for research aircraft simulation

    NASA Technical Reports Server (NTRS)

    Davis, Steven B.

    1990-01-01

    Visual aids are valuable assets to engineers for design, demonstration, and evaluation. Discussed here are a variety of advanced three-dimensional graphic techniques used to enhance the displays of test aircraft dynamics. The new software's capabilities are examined and possible future uses are considered.

  16. Exploring Advanced Techniques for Training an Artificial Neural Network on a Complex,

    E-print Network

    Meeden, Lisa A.

    Exploring Advanced Techniques for Training an Artificial Neural Network on a Complex, Multimodal. Artificial neural network (ANNs), inspired by the biologi- cal circuitry of the human brain, are one of the oldest and most versatile algorithms for machine learning. Academics and industry professionals have

  17. Fabrication of advanced electrochemical energy materials using sol-gel processing techniques

    NASA Technical Reports Server (NTRS)

    Chu, C. T.; Chu, Jay; Zheng, Haixing

    1995-01-01

    Advanced materials play an important role in electrochemical energy devices such as batteries, fuel cells, and electrochemical capacitors. They are being used as both electrodes and electrolytes. Sol-gel processing is a versatile solution technique used in fabrication of ceramic materials with tailored stoichiometry, microstructure, and properties. The application of sol-gel processing in the fabrication of advanced electrochemical energy materials will be presented. The potentials of sol-gel derived materials for electrochemical energy applications will be discussed along with some examples of successful applications. Sol-gel derived metal oxide electrode materials such as V2O5 cathodes have been demonstrated in solid-slate thin film batteries; solid electrolytes materials such as beta-alumina for advanced secondary batteries had been prepared by the sol-gel technique long time ago; and high surface area transition metal compounds for capacitive energy storage applications can also be synthesized with this method.

  18. The development of optical microscopy techniques for the advancement of single-particle studies

    SciTech Connect

    Marchuk, Kyle

    2013-05-15

    Single particle orientation and rotational tracking (SPORT) has recently become a powerful optical microscopy tool that can expose many molecular motions. Unfortunately, there is not yet a single microscopy technique that can decipher all particle motions in all environmental conditions, thus there are limitations to current technologies. Within, the two powerful microscopy tools of total internal reflection and interferometry are advanced to determine the position, orientation, and optical properties of metallic nanoparticles in a variety of environments. Total internal reflection is an optical phenomenon that has been applied to microscopy to produce either fluorescent or scattered light. The non-invasive far-field imaging technique is coupled with a near-field illumination scheme that allows for better axial resolution than confocal microscopy and epi-fluorescence microscopy. By controlling the incident illumination angle using total internal reflection fluorescence (TIRF) microscopy, a new type of imaging probe called “non-blinking” quantum dots (NBQDs) were super-localized in the axial direction to sub-10-nm precision. These particles were also used to study the rotational motion of microtubules being propelled by the motor protein kinesin across the substrate surface. The same instrument was modified to function under total internal reflection scattering (TIRS) microscopy to study metallic anisotropic nanoparticles and their dynamic interactions with synthetic lipid bilayers. Utilizing two illumination lasers with opposite polarization directions at wavelengths corresponding to the short and long axis surface plasmon resonance (SPR) of the nanoparticles, both the in-plane and out-of-plane movements of many particles could be tracked simultaneously. When combined with Gaussian point spread function (PSF) fitting for particle super-localization, the binding status and rotational movement could be resolved without degeneracy. TIRS microscopy was also used to find the 3D orientation of stationary metallic anisotropic nanoparticles utilizing only long-axis SPR enhancement. The polarization direction of the illuminating light was rotated causing the relative intensity of p-polarized and s-polarized light within the evanescent field to change. The interaction of the evanescent field with the particles is dependent on the orientation of the particle producing an intensity curve. This curve and the in-plane angle can be compared with simulations to accurately determine the 3D orientation. Differential interference contrast (DIC) microscopy is another non-invasive far-field technique based upon interferometry that does not rely on staining or other contrast enhancing techniques. In addition, high numerical aperture condensers and objectives can be used to give a very narrow depth of field allowing for the optical tomography of samples, which makes it an ideal candidate to study biological systems. DIC microscopy has also proven itself in determining the orientation of gold nanorods in both engineered environments and within cells. Many types of nanoparticles and nanostructures have been synthesized using lithographic techniques on silicon wafer substrates. Traditionally, reflective mode DIC microscopes have been developed and applied to the topographical study of reflective substrates and the imaging of chips on silicon wafers. Herein, a laser-illuminated reflected-mode DIC was developed for studying nanoparticles on reflective surfaces.

  19. The development of optical microscopy techniques for the advancement of single-particle studies

    NASA Astrophysics Data System (ADS)

    Marchuk, Kyle

    Single particle orientation and rotational tracking (SPORT) has recently become a powerful optical microscopy tool that can expose many molecular motions. Unfortunately, there is not yet a single microscopy technique that can decipher all particle motions in all environmental conditions, thus there are limitations to current technologies. Within, the two powerful microscopy tools of total internal reflection and interferometry are advanced to determine the position, orientation, and optical properties of metallic nanoparticles in a variety of environments. Total internal reflection is an optical phenomenon that has been applied to microscopy to produce either fluorescent or scattered light. The non-invasive far-field imaging technique is coupled with a near-field illumination scheme that allows for better axial resolution than confocal microscopy and epi-fluorescence microscopy. By controlling the incident illumination angle using total internal reflection fluorescence (TIRF) microscopy, a new type of imaging probe called "non-blinking" quantum dots (NBQDs) were super-localized in the axial direction to sub-10-nm precision. These particles were also used to study the rotational motion of microtubules being propelled by the motor protein kinesin across the substrate surface. The same instrument was modified to function under total internal reflection scattering (TIRS) microscopy to study metallic anisotropic nanoparticles and their dynamic interactions with synthetic lipid bilayers. Utilizing two illumination lasers with opposite polarization directions at wavelengths corresponding to the short and long axis surface plasmon resonance (SPR) of the nanoparticles, both the in-plane and out-of-plane movements of many particles could be tracked simultaneously. When combined with Gaussian point spread function (PSF) fitting for particle super-localization, the binding status and rotational movement could be resolved without degeneracy. TIRS microscopy was also used to find the 3D orientation of stationary metallic anisotropic nanoparticles utilizing only long-axis SPR enhancement. The polarization direction of the illuminating light was rotated causing the relative intensity of p-polarized and s-polarized light within the evanescent field to change. The interaction of the evanescent field with the particles is dependent on the orientation of the particle producing an intensity curve. This curve and the in-plane angle can be compared with simulations to accurately determine the 3D orientation. Differential interference contrast (DIC) microscopy is another non-invasive far-field technique based upon interferometry that does not rely on staining or other contrast enhancing techniques. In addition, high numerical aperture condensers and objectives can be used to give a very narrow depth of field allowing for the optical tomography of samples, which makes it an ideal candidate to study biological systems. DIC microscopy has also proven itself in determining the orientation of gold nanorods in both engineered environments and within cells. Many types of nanoparticles and nanostructures have been synthesized using lithographic techniques on silicon wafer substrates. Traditionally, reflective mode DIC microscopes have been developed and applied to the topographical study of reflective substrates and the imaging of chips on silicon wafers. Herein, a laser-illuminated reflected-mode DIC was developed for studying nanoparticles on reflective surfaces.

  20. Workshop on Magnetotactic Bacteria 9-11 June 2008, Balatonfred, Hungary Advanced electron microscopy techniques for studying

    E-print Network

    Dunin-Borkowski, Rafal E.

    , University of Pannonia, Veszprém, Hungary Several advanced transmission electron microscopy techniques using new and emerging electron microscopy techniques, including aberration-corrected electron microscopy, focused ion beam sectioning, live cell imaging in both transmission and scanning electron

  1. Achieving molecular selectivity in imaging using multiphoton Raman spectroscopy techniques

    SciTech Connect

    Holtom, Gary R. ); Thrall, Brian D. ); Chin, Beek Yoke ); Wiley, H Steven ); Colson, Steven D. )

    2000-12-01

    In the case of most imaging methods, contrast is generated either by physical properties of the sample (Differential Image Contrast, Phase Contrast), or by fluorescent labels that are localized to a particular protein or organelle. Standard Raman and infrared methods for obtaining images are based upon the intrinsic vibrational properties of molecules, and thus obviate the need for attached flurophores. Unfortunately, they have significant limitations for live-cell imaging. However, an active Raman method, called Coherent Anti-Stokes Raman Scattering (CARS), is well suited for microscopy, and provides a new means for imaging specific molecules. Vibrational imaging techniques, such as CARS, avoid problems associated with photobleaching and photo-induced toxicity often associated with the use of fluorescent labels with live cells. Because the laser configuration needed to implement CARS technology is similar to that used in other multiphoton microscopy methods, such as two -photon fluorescence and harmonic generation, it is possible to combine imaging modalities, thus generating simultaneous CARS and fluorescence images. A particularly powerful aspect of CARS microscopy is its ability to selectively image deuterated compounds, thus allowing the visualization of molecules, such as lipids, that are chemically indistinguishable from the native species.

  2. Advanced techniques for determining long term compatibility of materials with propellants

    NASA Technical Reports Server (NTRS)

    Green, R. L.

    1972-01-01

    The search for advanced measurement techniques for determining long term compatibility of materials with propellants was conducted in several parts. A comprehensive survey of the existing measurement and testing technology for determining material-propellant interactions was performed. Selections were made from those existing techniques which were determined could meet or be made to meet the requirements. Areas of refinement or changes were recommended for improvement of others. Investigations were also performed to determine the feasibility and advantages of developing and using new techniques to achieve significant improvements over existing ones. The most interesting demonstration was that of the new technique, the volatile metal chelate analysis. Rivaling the neutron activation analysis in terms of sensitivity and specificity, the volatile metal chelate technique was fully demonstrated.

  3. Advances in ion mobility-mass spectrometry instrumentation and techniques for characterizing structural heterogeneity.

    PubMed

    Maurer, Megan M; Donohoe, Gregory C; Valentine, Stephen J

    2015-10-21

    Over the last decade, the field of ion mobility-mass spectrometry (IM-MS) has experienced dramatic growth in its application toward ion structure characterization. Enabling advances in instrumentation during this time period include improved conformation resolution and ion sensitivity. Such advances have rendered IM-MS a powerful approach for characterizing samples presenting a diverse array of ion structures. The structural heterogeneity that can be interrogated by IM-MS techniques now ranges from samples containing mixtures of small molecules exhibiting a variety of structural types to those containing very large protein complexes and subcomplexes. In addition to this diversity, IM-MS techniques have been used to probe spontaneous and induced structural transformations occurring in solution or the gas phase. To support these measurement efforts, significant advances have been made in theoretical methods aimed at translating IM-MS data into structural information. These efforts have ranged from providing more reliable trial structures for comparison to the experimental measurements to dramatically reducing the time required to calculate collision cross sections for such structures. In this short review, recent advances in developments in IM-MS instrumentation, techniques, and theory are discussed with regard to their implications for characterization of gas- and solution-phase structural heterogeneity. PMID:26114255

  4. Rotational spectra of N2 + : An advanced undergraduate laboratory in atomic and molecular spectroscopy

    NASA Astrophysics Data System (ADS)

    Bayram, S. B.; Arndt, P. T.; Freamat, M. V.

    2015-10-01

    We describe an inexpensive instructional experiment that demonstrates the rotational energy levels of diatomic nitrogen, using the emission band spectrum of molecular nitrogen ionized by various processes in a commercial ac capillary discharge tube. The simple setup and analytical procedure is introduced as part of a sequence of educational experiments employed by a course of advanced atomic and molecular spectroscopy, where the study of rotational spectra is combined with the analysis of vibrational characteristics for a multifaceted picture of the quantum states of diatomic molecules.

  5. Unified Instrumentation: Examining the Simultaneous Application of Advanced Measurement Techniques for Increased Wind Tunnel Testing Capability

    NASA Technical Reports Server (NTRS)

    Fleming, Gary A. (Editor); Bartram, Scott M.; Humphreys, William M., Jr.; Jenkins, Luther N.; Jordan, Jeffrey D.; Lee, Joseph W.; Leighty, Bradley D.; Meyers, James F.; South, Bruce W.; Cavone, Angelo A.; Ingram, JoAnne L.

    2002-01-01

    A Unified Instrumentation Test examining the combined application of Pressure Sensitive Paint, Projection Moire Interferometry, Digital Particle Image Velocimetry, Doppler Global Velocimetry, and Acoustic Microphone Array has been conducted at the NASA Langley Research Center. The fundamental purposes of conducting the test were to: (a) identify and solve compatibility issues among the techniques that would inhibit their simultaneous application in a wind tunnel, and (b) demonstrate that simultaneous use of advanced instrumentation techniques is feasible for increasing tunnel efficiency and identifying control surface actuation / aerodynamic reaction phenomena. This paper provides summary descriptions of each measurement technique used during the Unified Instrumentation Test, their implementation for testing in a unified fashion, and example results identifying areas of instrument compatibility and incompatibility. Conclusions are drawn regarding the conditions under which the measurement techniques can be operated simultaneously on a non-interference basis. Finally, areas requiring improvement for successfully applying unified instrumentation in future wind tunnel tests are addressed.

  6. POC-Scale Testing of an Advanced Fine Coal Dewatering Equipment/Technique.

    SciTech Connect

    Tao, D.; Groppo, J.G.; Parekh, B.K.

    1997-11-05

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 mm) clean coal. Economical dewatering of an ultra-fine clean-coal product to a 20% level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20% or lower moisture using either conventional or advanced dewatering techniques. The cost-sharing contract effort is for 36 months beginning September 30, 1994. This report discusses technical progress made during the quarter from July 1 - September 30, 1997.

  7. POC-Scale Testing of an Advanced Fine Coal Dewatering Equipment/Technique.

    SciTech Connect

    Tao, D.; Groppo, J.G.; Parekh, B.K.

    1997-12-31

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 mm) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20% level moisture will be an important step in the successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20% or lower moisture using either conventional or advanced dewatering techniques. The cost-sharing contract effort is for 36 months beginning September 30, 1994. This report discusses technical progress made during the quarter from April 1 - June 30, 1997.

  8. POC-scale testing of an advanced fine coal dewatering equipment/technique

    SciTech Connect

    1998-09-01

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 pm) clean coal. Economical dewatering of an ultra-fine clean-coal product to a 20% level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20% or lower moisture using either conventional or advanced dewatering techniques. The cost-sharing contract effort is for 36 months beginning September 30, 1994. This report discusses technical progress made during the quarter from July 1 - September 30, 1997.

  9. Flaw Detection for Composite Materials Improved by Advanced Thermal Image Reconstruction Techniques

    NASA Technical Reports Server (NTRS)

    Martin, Richard E.; Gyekenyesi, Andrew L.

    2003-01-01

    The development of advanced composite materials for use in space and propulsion components has seen considerable growth over the past few years. In addition to improvements that have been made in material properties and processing techniques, similar growth must be seen in the development of methods for the detection of flaws, either generated in service or during manufacturing. Thermal imaging techniques have proven to be successful for the nondestructive evaluation (NDE) of composite materials, but their detection capabilities decrease as flaw depth increases. The purpose of this research is to investigate advanced thermal imaging methods and thermal image processing technologies to increase the maximum depth below surface that a flaw can be detected and improve the contrast between flawed regions and sound regions.

  10. An example of requirements for Advanced Subsonic Civil Transport (ASCT) flight control system using structured techniques

    NASA Technical Reports Server (NTRS)

    Mclees, Robert E.; Cohen, Gerald C.

    1991-01-01

    The requirements are presented for an Advanced Subsonic Civil Transport (ASCT) flight control system generated using structured techniques. The requirements definition starts from initially performing a mission analysis to identify the high level control system requirements and functions necessary to satisfy the mission flight. The result of the study is an example set of control system requirements partially represented using a derivative of Yourdon's structured techniques. Also provided is a research focus for studying structured design methodologies and in particular design-for-validation philosophies.

  11. [Principles and advanced techniques for better internetpresentations in obstetrics and gynecology].

    PubMed

    Seufert, R; Molitor, N; Pollow, K; Woernle, F; Hawighorst-Knapstein, S

    2001-08-01

    Internet presentations are common tools for better medical communication and better scientific work. Meanwhile a great number of gynecological and obstetrical institutions present data via the world wide web within a wide range of quality and performance. Specific HTML editors offer quick and easy presentations, but only advanced internet techniques enable interesting multimedia presentations. N-tier applications are the future standard and we must integrate them in general informatical systems. New Concepts, actual tools and general problems will be discussed and new principles similar to actual E commerce techniques are able to solve our special medical demands. PMID:11562809

  12. Recent advances in endpoint and in-line monitoring techniques for chemical-mechanical polishing processes

    NASA Astrophysics Data System (ADS)

    Stein, David J.; Hetherington, Dale L.

    2001-04-01

    We present a summary of the recent advances in endpoint and in-line monitoring techniques for chemical-mechanical polishing (CMP) processes. We discuss the technical challenges and review some of the approaches that have been published and/or patented. These methods include optical, thermal (pad temperature), friction (torque motor current), electrochemical, chemical, electrical, and acoustic (vibration). We also present experimental data obtained in our laboratory using selected endpoint methods for metal and oxide CMP.

  13. Study of advanced techniques for determining the long term performance of components

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The application of existing and new technology to the problem of determining the long-term performance capability of liquid rocket propulsion feed systems is discussed. The long term performance of metal to metal valve seats in a liquid propellant fuel system is stressed. The approaches taken in conducting the analysis are: (1) advancing the technology of characterizing components through the development of new or more sensitive techniques and (2) improving the understanding of the physical of degradation.

  14. Monte Carlo and Molecular Dynamics Tools 3. Monte Carlo techniques for time evolution

    E-print Network

    Sjöstrand, Torbjörn

    Monte Carlo and Molecular Dynamics Tools 3. Monte Carlo techniques for time evolution Torbj¨orn Sj for it to decay at time t Naively P(t) = c = N(t) = 1 - ct. Wrong! Conservation of probability driven by depletion

  15. Eigensolution techniques, their applications and the Fisher's information entropy of Tietz-Wei diatomic molecular potential

    E-print Network

    Falaye, B J; Ikhdair, S M; Hamzavi, M

    2014-01-01

    In this study, approximate analytical solution of Schr\\"odinger, Klein-Gordon and Dirac equations under the Tietz-Wei (TW) diatomic molecular potential are represented by using an approximation for the centrifugal term. We have applied three types of eigensolution techniques; the functional analysis approach (FAA), supersymmetry quantum mechanics (SUSYQM) and asymptotic iteration method (AIM) to solve Klein-Gordon Dirac and Schr\\"odinger equations, respectively. The energy eigenvalues and the corresponding eigenfunctions for these three wave equations are obtained and some numerical results and figures are reported. It has been shown that these techniques yielded exactly same results. some expectation values of the TW diatomic molecular potential within the framework of the Hellmann-Feynman theorem (HFT) have been presented. The probability distributions which characterize the quantum-mechanical states of TW diatomic molecular potential are analysed by means of complementary information measures of a probabil...

  16. POC-scale testing of an advanced fine coal dewatering equipment/technique

    SciTech Connect

    Groppo, J.G.; Parekh, B.K.; Rawls, P.

    1995-11-01

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 {mu}m) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20 percent level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20 percent or lower moisture using either conventional or advanced dewatering techniques. As the contract title suggests, the main focus of the program is on proof-of-concept testing of a dewatering technique for a fine clean coal product. The coal industry is reluctant to use the advanced fine coal recovery technology due to the non-availability of an economical dewatering process. in fact, in a recent survey conducted by U.S. DOE and Battelle, dewatering of fine clean coal was identified as the number one priority for the coal industry. This project will attempt to demonstrate an efficient and economic fine clean coal slurry dewatering process.

  17. Recent advances in small molecular, non-polymeric organic hole transporting materials for solid-state DSSC

    NASA Astrophysics Data System (ADS)

    Bui, Thanh-Tuan; Goubard, Fabrice

    2013-10-01

    Issue from thin-film technologies, dye-sensitized solar cells have become one of the most promising technologies in the field of renewable energies. Their success is not only due to their low weight, the possibility of making large flexible surfaces, but also to their photovoltaic efficiency which are found to be more and more significant (>12% with a liquid electrolyte, >7% with a solid organic hole conductor). This short review highlights recent advances in the characteristics and use of low-molecular-weight glass-forming organic materials as hole transporters in all solid-state dye-sensitized solar cells. These materials must feature specific physical and chemical properties that will ensure both the operation of a photovoltaic cell and the easy implementation. This review is an english extended version based on our recent article published in Matériaux & Techniques 101, 102 (2013).

  18. ADVANCING THE FUNDAMENTAL UNDERSTANDING AND SCALE-UP OF TRISO FUEL COATERS VIA ADVANCED MEASUREMENT AND COMPUTATIONAL TECHNIQUES

    SciTech Connect

    Biswas, Pratim; Al-Dahhan, Muthanna

    2012-11-01

    Tri-isotropic (TRISO) fuel particle coating is critical for the future use of nuclear energy produced byadvanced gas reactors (AGRs). The fuel kernels are coated using chemical vapor deposition in a spouted fluidized bed. The challenges encountered in operating TRISO fuel coaters are due to the fact that in modern AGRs, such as High Temperature Gas Reactors (HTGRs), the acceptable level of defective/failed coated particles is essentially zero. This specification requires processes that produce coated spherical particles with even coatings having extremely low defect fractions. Unfortunately, the scale-up and design of the current processes and coaters have been based on empirical approaches and are operated as?black boxes. Hence, a voluminous amount of experimental development and trial and error work has been conducted. It has been clearly demonstrated that the quality of the coating applied to the fuel kernels is impacted by the hydrodynamics, solids flow field, and flow regime characteristics of the spouted bed coaters, which themselves are influenced by design parameters and operating variables. Further complicating the outlook for future fuel-coating technology and nuclear energy production is the fact that a variety of new concepts will involve fuel kernels of different sizes and with compositions of different densities. Therefore, without a fundamental understanding the underlying phenomena of the spouted bed TRISO coater, a significant amount of effort is required for production of each type of particle with a significant risk of not meeting the specifications. This difficulty will significantly and negatively impact the applications of AGRs for power generation and cause further challenges to them as an alternative source of commercial energy production. Accordingly, the proposed work seeks to overcome such hurdles and advance the scale-up, design, and performance of TRISO fuel particle spouted bed coaters. The overall objectives of the proposed work are to advance the fundamental understanding of the hydrodynamics by systematically investigating the effect of design and operating variables, to evaluate the reported dimensionless groups as scaling factors, and to establish a reliable scale-up methodology for the TRISO fuel particle spouted bed coaters based on hydrodynamic similarity via advanced measurement and computational techniques. An additional objective is to develop an on-line non-invasive measurement technique based on gamma ray densitometry (i.e. Nuclear Gauge Densitometry) that can be installed and used for coater process monitoring to ensure proper performance and operation and to facilitate the developed scale-up methodology. To achieve the objectives set for the project, the work will use optical probes and gamma ray computed tomography (CT) (for the measurements of solids/voidage holdup cross-sectional distribution and radial profiles along the bed height, spouted diameter, and fountain height) and radioactive particle tracking (RPT) (for the measurements of the 3D solids flow field, velocity, turbulent parameters, circulation time, solids lagrangian trajectories, and many other of spouted bed related hydrodynamic parameters). In addition, gas dynamic measurement techniques and pressure transducers will be utilized to complement the obtained information. The measurements obtained by these techniques will be used as benchmark data to evaluate and validate the computational fluid dynamic (CFD) models (two fluid model or discrete particle model) and their closures. The validated CFD models and closures will be used to facilitate the developed methodology for scale-up, design and hydrodynamic similarity. Successful execution of this work and the proposed tasks will advance the fundamental understanding of the coater flow field and quantify it for proper and safe design, scale-up, and performance. Such achievements will overcome the barriers to AGR applications and will help assure that the US maintains nuclear energy as a feasible option to meet the nationÃ?Â?Ã?Â?Ã

  19. PET/SPECT molecular imaging in clinical neuroscience: recent advances in the investigation of CNS diseases

    PubMed Central

    Lu, Feng-Mei

    2015-01-01

    Molecular imaging is an attractive technology widely used in clinical practice that greatly enhances our understanding of the pathophysiology and treatment in central nervous system (CNS) diseases. It is a novel multidisciplinary technique that can be defined as real-time visualization, in vivo characterization and qualification of biological processes at the molecular and cellular level. It involves the imaging modalities and the corresponding imaging agents. Nowadays, molecular imaging in neuroscience has provided tremendous insights into disturbed human brain function. Among all of the molecular imaging modalities, positron emission tomography (PET) and single photon emission computed tomography (SPECT) have occupied a particular position that visualize and measure the physiological processes using high-affinity and high-specificity molecular radioactive tracers as imaging probes in intact living brain. In this review, we will put emphasis on the PET/SPECT applications in Alzheimer’s disease (AD) and Parkinson’s disease (PD) as major CNS disorders. We will first give an overview of the main classical molecular neuroimaging modalities. Then, the major clinical applications of PET and SPECT along with molecular probes in the fields of psychiatry and neurology will be discussed. PMID:26029646

  20. Molecular Technique to Reduce PCR Bias for Deeper Understanding of Microbial Diversity

    NASA Technical Reports Server (NTRS)

    Vaishampayan, Parag A.; Venkateswaran, Kasthuri J.

    2012-01-01

    Current planetary protection policies require that spacecraft targeted to sensitive solar system bodies be assembled and readied for launch in controlled cleanroom environments. A better understanding of the distribution and frequency at which high-risk contaminant microbes are encountered on spacecraft surfaces would significantly aid in assessing the threat of forward contamination. However, despite a growing understanding of the diverse microbial populations present in cleanrooms, less abundant microbial populations are probably not adequately taken into account due to technological limitations. This novel approach encompasses a wide spectrum of microbial species and will represent the true picture of spacecraft cleanroom-associated microbial diversity. All of the current microbial diversity assessment techniques are based on an initial PCR amplification step. However, a number of factors are known to bias PCR amplification and jeopardize the true representation of bacterial diversity. PCR amplification of a minor template appears to be suppressed by the amplification of a more abundant template. It is widely acknowledged among environmental molecular microbiologists that genetic biosignatures identified from an environment only represent the most dominant populations. The technological bottleneck overlooks the presence of the less abundant minority population and may underestimate their role in the ecosystem maintenance. DNA intercalating agents such as propidium monoazide (PMA) covalently bind with DNA molecules upon photolysis using visible light, and make it unavailable for DNA polymerase enzyme during polymerase chain reaction (PCR). Environmental DNA samples will be treated with suboptimum PMA concentration, enough to intercalate with 90 99% of the total DNA. The probability of PMA binding with DNA from abundant bacterial species will be much higher than binding with DNA from less abundant species. This will increase the relative DNA concentration of previously "shadowed" less abundant species available for PCR amplification. These PCR products obtained with and without PMA treatment will then be subjected to downstream diversity analyses such as sequencing and DNA microarray. It is expected that PMA-coupled PCR will amplify the "minority population" and help in understanding microbial diversity spectrum of an environmental sample at a much deeper level. This new protocol aims to overcome the major potential biases faced when analyzing microbial 16S rRNA gene diversity. This study will lead to a technological advancement and a commercial product that will aid microbial ecologists in understanding microbial diversity from various environmental niches. Implementation of this technique may lead to discoveries of novel microbes and their functions in sustenance of the ecosystem.

  1. Molecular tagging techniques and their applications to the study of complex thermal flow phenomena

    NASA Astrophysics Data System (ADS)

    Chen, Fang; Li, Haixing; Hu, Hui

    2015-08-01

    This review article reports the recent progress in the development of a new group of molecule-based flow diagnostic techniques, which include molecular tagging velocimetry (MTV) and molecular tagging thermometry (MTT), for both qualitative flow visualization of thermally induced flow structures and quantitative whole-field measurements of flow velocity and temperature distributions. The MTV and MTT techniques can also be easily combined to result in a so-called molecular tagging velocimetry and thermometry (MTV&T) technique, which is capble of achieving simultaneous measurements of flow velocity and temperature distribution in fluid flows. Instead of using tiny particles, the molecular tagging techniques (MTV, MTT, and MTV&T) use phosphorescent molecules, which can be turned into long-lasting glowing marks upon excitation by photons of appropriate wavelength, as the tracers for the flow velocity and temperature measurements. The unique attraction and implementation of the molecular tagging techniques are demonstrated by three application examples, which include: (1) to quantify the unsteady heat transfer process from a heated cylinder to the surrounding fluid flow in order to examine the thermal effects on the wake instabilities behind the heated cylinder operating in mixed and forced heat convection regimes, (2) to reveal the time evolution of unsteady heat transfer and phase changing process inside micro-sized, icing water droplets in order to elucidate the underlying physics pertinent to aircraft icing phenomena, and (3) to achieve simultaneous droplet size, velocity and temperature measurements of "in-flight" droplets to characterize the dynamic and thermodynamic behaviors of flying droplets in spray flows.

  2. Accelerated Testing Methodology in Constant Stress-Rate Testing for Advanced Structural Ceramics: A Preloading Technique

    NASA Technical Reports Server (NTRS)

    Choi, Sung R.; Gyekenyesi, John P.; Huebert, Dean; Bartlett, Allen; Choi, Han-Ho

    2001-01-01

    Preloading technique was used as a means of an accelerated testing methodology in constant stress-rate (dynamic fatigue) testing for two different brittle materials. The theory developed previously for fatigue strength as a function of preload was further verified through extensive constant stress-rate testing for glass-ceramic and CRT glass in room temperature distilled water. The preloading technique was also used in this study to identify the prevailing failure mechanisms at elevated temperatures, particularly at lower test rates in which a series of mechanisms would be associated simultaneously with material failure, resulting in significant strength increase or decrease. Two different advanced ceramics including SiC whisker-reinforced composite silicon nitride and 96 wt% alumina were used at elevated temperatures. It was found that the preloading technique can be used as an additional tool to pinpoint the dominant failure mechanism that is associated with such a phenomenon of considerable strength increase or decrease.

  3. Charge transport in molecular junctions: From tunneling to hopping with the probe technique

    NASA Astrophysics Data System (ADS)

    Kilgour, Michael; Segal, Dvira

    2015-07-01

    We demonstrate that a simple phenomenological approach can be used to simulate electronic conduction in molecular wires under thermal effects induced by the surrounding environment. This "Landauer-Büttiker's probe technique" can properly replicate different transport mechanisms, phase coherent nonresonant tunneling, ballistic behavior, and hopping conduction. Specifically, our simulations with the probe method recover the following central characteristics of charge transfer in molecular wires: (i) the electrical conductance of short wires falls off exponentially with molecular length, a manifestation of the tunneling (superexchange) mechanism. Hopping dynamics overtakes superexchange in long wires demonstrating an ohmic-like behavior. (ii) In off-resonance situations, weak dephasing effects facilitate charge transfer, but under large dephasing, the electrical conductance is suppressed. (iii) At high enough temperatures, kBT/?B > 1/25, with ?B as the molecular-barrier height, the current is enhanced by a thermal activation (Arrhenius) factor. However, this enhancement takes place for both coherent and incoherent electrons and it does not readily indicate on the underlying mechanism. (iv) At finite-bias, dephasing effects may impede conduction in resonant situations. We further show that memory (non-Markovian) effects can be implemented within the Landauer-Büttiker's probe technique to model the interaction of electrons with a structured environment. Finally, we examine experimental results of electron transfer in conjugated molecular wires and show that our computational approach can reasonably reproduce reported values to provide mechanistic information.

  4. Charge transport in molecular junctions: From tunneling to hopping with the probe technique.

    PubMed

    Kilgour, Michael; Segal, Dvira

    2015-07-14

    We demonstrate that a simple phenomenological approach can be used to simulate electronic conduction in molecular wires under thermal effects induced by the surrounding environment. This "Landauer-Büttiker's probe technique" can properly replicate different transport mechanisms, phase coherent nonresonant tunneling, ballistic behavior, and hopping conduction. Specifically, our simulations with the probe method recover the following central characteristics of charge transfer in molecular wires: (i) the electrical conductance of short wires falls off exponentially with molecular length, a manifestation of the tunneling (superexchange) mechanism. Hopping dynamics overtakes superexchange in long wires demonstrating an ohmic-like behavior. (ii) In off-resonance situations, weak dephasing effects facilitate charge transfer, but under large dephasing, the electrical conductance is suppressed. (iii) At high enough temperatures, kBT/?B > 1/25, with ?B as the molecular-barrier height, the current is enhanced by a thermal activation (Arrhenius) factor. However, this enhancement takes place for both coherent and incoherent electrons and it does not readily indicate on the underlying mechanism. (iv) At finite-bias, dephasing effects may impede conduction in resonant situations. We further show that memory (non-Markovian) effects can be implemented within the Landauer-Büttiker's probe technique to model the interaction of electrons with a structured environment. Finally, we examine experimental results of electron transfer in conjugated molecular wires and show that our computational approach can reasonably reproduce reported values to provide mechanistic information. PMID:26178094

  5. Advances in Rosetta structure prediction for difficult molecular-replacement problems

    SciTech Connect

    DiMaio, Frank

    2013-11-01

    Modeling advances using Rosetta structure prediction to aid in solving difficult molecular-replacement problems are discussed. Recent work has shown the effectiveness of structure-prediction methods in solving difficult molecular-replacement problems. The Rosetta protein structure modeling suite can aid in the solution of difficult molecular-replacement problems using templates from 15 to 25% sequence identity; Rosetta refinement guided by noisy density has consistently led to solved structures where other methods fail. In this paper, an overview of the use of Rosetta for these difficult molecular-replacement problems is provided and new modeling developments that further improve model quality are described. Several variations to the method are introduced that significantly reduce the time needed to generate a model and the sampling required to improve the starting template. The improvements are benchmarked on a set of nine difficult cases and it is shown that this improved method obtains consistently better models in less running time. Finally, strategies for best using Rosetta to solve difficult molecular-replacement problems are presented and future directions for the role of structure-prediction methods in crystallography are discussed.

  6. A sensor device with specific recognition sites for formaldehyde based on molecular imprinting technique

    NASA Astrophysics Data System (ADS)

    Zhang, Yumin; Zhang, Jin; Zhu, Zhongqi; Liu, Qingju

    2015-07-01

    A novel gas sensor for the detection of formaldehyde was developed based on molecular imprinting technique (MIT) with formaldehyde as template. The structure of the molecular imprinting nanoparticles (MINs) is of orthogonal perovskite. The MINs with a good dispersion possess high surface-to-volume ratio. The particles are spherical and uniform, and then the MINs are printed onto an alumina tube to form a sensor device. At 92°C, the response to 1 ppm formaldehyde based on the sensor is 8, while the response to the other test gases is less than 3. The response time and recovery time are 40 s and 90 s, respectively.

  7. Review of recent advances in analytical techniques for the determination of neurotransmitters

    PubMed Central

    Perry, Maura; Li, Qiang; Kennedy, Robert T.

    2009-01-01

    Methods and advances for monitoring neurotransmitters in vivo or for tissue analysis of neurotransmitters over the last five years are reviewed. The review is organized primarily by neurotransmitter type. Transmitter and related compounds may be monitored by either in vivo sampling coupled to analytical methods or implanted sensors. Sampling is primarily performed using microdialysis, but low-flow push-pull perfusion may offer advantages of spatial resolution while minimizing the tissue disruption associated with higher flow rates. Analytical techniques coupled to these sampling methods include liquid chromatography, capillary electrophoresis, enzyme assays, sensors, and mass spectrometry. Methods for the detection of amino acid, monoamine, neuropeptide, acetylcholine, nucleoside, and soluable gas neurotransmitters have been developed and improved upon. Advances in the speed and sensitivity of these methods have enabled improvements in temporal resolution and increased the number of compounds detectable. Similar advances have enabled improved detection at tissue samples, with a substantial emphasis on single cell and other small samples. Sensors provide excellent temporal and spatial resolution for in vivo monitoring. Advances in application to catecholamines, indoleamines, and amino acids have been prominent. Improvements in stability, sensitivity, and selectivity of the sensors have been of paramount interest. PMID:19800472

  8. Advances and Perspectives in the Molecular Diagnosis of Head and Neck Cancer

    PubMed Central

    Mydlarz, Wojciech K.; Hennessey, Patrick T.; Califano, Joseph A.

    2009-01-01

    Background Head and neck squamous cell carcinoma (HNSCC) is a debilitating and lethal disease. Despite significant advances in radiotherapy and surgical management, the 5-year survival rate for head and neck cancer has remained a dismal 50%. Advances in early detection have been made, but to improve patient outcomes better biomarkers and targeted therapeutic agents are needed. Novel biomarkers can improve early detection and provide data to optimize therapeutic strategy and patient survival, and could lead to potentially effective targeted therapies. Objective Report the advances in the discovery of novel biomarkers for HNSCC, and review the potential utility of biomarkers in the molecular diagnosis of HNSCC. Methods A review of the English literature (PubMed) from 1980 to 2009. Results/conclusion Currently the most widely accepted biomarker for HNSCC is high risk HPV status. EGFR is another promising biomarker, however, further research is necessary to determine its prognostic benefit. A large number of promising biomarker candidates are currently being evaluated including epigenetic, expression, and genomic based markers. Studies to validate the sensitivity and specificity of these biomarkers in clinical samples from adequately powered prospective cohorts are needed for successful translation of these findings into potential molecular diagnostic, prognostic, and therapeutic biomarkers for HNSCC. PMID:20161611

  9. System engineering techniques for establishing balanced design and performance guidelines for the advanced telerobotic testbed

    NASA Technical Reports Server (NTRS)

    Zimmerman, W. F.; Matijevic, J. R.

    1987-01-01

    Novel system engineering techniques have been developed and applied to establishing structured design and performance objectives for the Telerobotics Testbed that reduce technical risk while still allowing the testbed to demonstrate an advancement in state-of-the-art robotic technologies. To estblish the appropriate tradeoff structure and balance of technology performance against technical risk, an analytical data base was developed which drew on: (1) automation/robot-technology availability projections, (2) typical or potential application mission task sets, (3) performance simulations, (4) project schedule constraints, and (5) project funding constraints. Design tradeoffs and configuration/performance iterations were conducted by comparing feasible technology/task set configurations against schedule/budget constraints as well as original program target technology objectives. The final system configuration, task set, and technology set reflected a balanced advancement in state-of-the-art robotic technologies, while meeting programmatic objectives and schedule/cost constraints.

  10. Advanced techniques and technology for efficient data storage, access, and transfer

    NASA Technical Reports Server (NTRS)

    Rice, Robert F.; Miller, Warner

    1991-01-01

    Advanced techniques for efficiently representing most forms of data are being implemented in practical hardware and software form through the joint efforts of three NASA centers. These techniques adapt to local statistical variations to continually provide near optimum code efficiency when representing data without error. Demonstrated in several earlier space applications, these techniques are the basis of initial NASA data compression standards specifications. Since the techniques clearly apply to most NASA science data, NASA invested in the development of both hardware and software implementations for general use. This investment includes high-speed single-chip very large scale integration (VLSI) coding and decoding modules as well as machine-transferrable software routines. The hardware chips were tested in the laboratory at data rates as high as 700 Mbits/s. A coding module's definition includes a predictive preprocessing stage and a powerful adaptive coding stage. The function of the preprocessor is to optimally process incoming data into a standard form data source that the second stage can handle.The built-in preprocessor of the VLSI coder chips is ideal for high-speed sampled data applications such as imaging and high-quality audio, but additionally, the second stage adaptive coder can be used separately with any source that can be externally preprocessed into the 'standard form'. This generic functionality assures that the applicability of these techniques and their recent high-speed implementations should be equally broad outside of NASA.

  11. Nonlinear Raman Techniques in Femtosecond Time Resolved Spectroscopy for the Analysis and Control of Molecular Dynamics

    SciTech Connect

    Materny, Arnulf; Konradi, Jakow; Namboodiri, Vinu; Namboodiri, Mahesh; Scaria, Abraham

    2008-11-14

    The use of four-wave mixing techniques in femtosecond time-resolved spectroscopy has considerable advantages. Due to the many degrees of freedom offered e.g. by coherent anti-Stokes Raman scattering (CARS), the dynamics even of complex systems can be analyzed in detail. Using pulse shaping techniques in combination with a self-learning loop approach, molecular mode excitation can be controlled very efficiently in a multi-photon excitation process. Results obtained from the optimal control of CARS on {beta}-carotene are discussed.

  12. Determination of Electromagnetic Properties of Mesh Material Using Advanced Radiometer Techniques

    NASA Technical Reports Server (NTRS)

    Arrington, R. F.; Blume, H. J. C.

    1985-01-01

    The need for a large diameter deployable antenna to map soil moisture with a 10 kilometer or better resolution using a microwave radiometer is discussed. A 6 meter deployable antenna is also needed to map sea surface temperature on the Navy Remote Ocean Sensor System (NROSS). Both of these deployable antennas require a mesh membrane material as the reflecting surface. The determination of the electromagnetic properties of mesh materials is a difficult problem. The Antenna and Microwave Research Branch (AMRB) of Langley Research Center was asked to measure the material to be used on MROSS by NRL. A cooperative program was initiated to measure this mesh material using two advanced radiometer techniques.

  13. Molecular Prognostic Prediction for Locally Advanced Nasopharyngeal Carcinoma by Support Vector Machine Integrated Approach

    PubMed Central

    Zhang, Yan; Chen, Ming-Yuan; Xu, Jie; Wu, Xiang-Yuan; Li, Hong-Bo; Zeng, Yi-Xin; Hong, Ming-Huang; Liu, Quentin

    2012-01-01

    Background Accurate prognostication of locally advanced nasopharyngeal carcinoma (NPC) will benefit patients for tailored therapy. Here, we addressed this issue by developing a mathematical algorithm based on support vector machine (SVM) through integrating the expression levels of multi-biomarkers. Methodology/Principal Findings Ninety-seven locally advanced NPC patients in a randomized controlled trial (RCT), consisting of 48 cases serving as training set and 49 cases as testing set of SVM models, with 5-year follow-up were studied. We designed SVM models by selecting the variables from 38 tissue molecular biomarkers, which represent 6 tumorigenesis signaling pathways, and 3 EBV-related serological biomarkers. We designed 3 SVM models to refine prognosis of NPC with 5-year follow-up. The SVM1 displayed highly predictive sensitivity (sensitivity, specificity were 88.0% and 81.9%, respectively) by integrating the expression of 7 molecular biomarkers. The SVM2 model showed highly predictive specificity (sensitivity, specificity were 84.0% and 94.5%, respectively) by grouping the expression level of 12 molecular biomarkers and 3 EBV-related serological biomarkers. The SVM3 model, constructed by combination SVM1 with SVM2, displayed a high predictive capacity (sensitivity, specificity were 88.0% and 90.3%, respectively). We found that 3 SVM models had strong power in classification of prognosis. Moreover, Cox multivariate regression analysis confirmed these 3 SVM models were all the significant independent prognostic model for overall survival in testing set and overall patients. Conclusions/Significance Our SVM prognostic models designed in the RCT displayed strong power in refining patient prognosis for locally advanced NPC, potentially directing future target therapy against the related signaling pathways. PMID:22427815

  14. New Strategies in Pediatric Gliomas: Molecular Advances in Pediatric Low-Grade Gliomas as a Model

    PubMed Central

    Raabe, Eric; Kieran, Mark W.; Cohen, Kenneth J.

    2015-01-01

    Pediatric low-grade gliomas (pLGG) account for more brain tumors in children than any other histologic subtype. While surgery, chemotherapy and radiation remain the mainstay of upfront treatment, recent advances in molecular interrogation of pLGG have shown a small number of recurring genetic mutations in these tumors that might be exploited therapeutically. Notable findings include abnormalities in the RAS/MAP kinase pathway such as NF-1 loss or BRAF activation and mTOR activation. Recent identification of activating re-arrangements in c-MYB and MYBL1 in pediatric diffuse astrocytoma also provide candidates for therapeutic intervention. Targeting these molecularly identified pathways may allow for improved outcomes for patients as pediatric oncology moves into the era of biology-driven medicine. PMID:23881924

  15. Vascular effects of advanced glycation endproducts: Clinical effects and molecular mechanisms?

    PubMed Central

    Stirban, Alin; Gawlowski, Thomas; Roden, Michael

    2013-01-01

    The enhanced generation and accumulation of advanced glycation endproducts (AGEs) have been linked to increased risk for macrovascular and microvascular complications associated with diabetes mellitus. AGEs result from the nonenzymatic reaction of reducing sugars with proteins, lipids, and nucleic acids, potentially altering their function by disrupting molecular conformation, promoting cross-linking, altering enzyme activity, reducing their clearance, and impairing receptor recognition. AGEs may also activate specific receptors, like the receptor for AGEs (RAGE), which is present on the surface of all cells relevant to atherosclerotic processes, triggering oxidative stress, inflammation and apoptosis. Understanding the pathogenic mechanisms of AGEs is paramount to develop strategies against diabetic and cardiovascular complications. PMID:24634815

  16. Recent advances in coupling capillary electrophoresis based separation techniques to ESI and MALDI MS

    PubMed Central

    Zhong, Xuefei; Zhang, Zichuan; Jiang, Shan; Li, Lingjun

    2014-01-01

    Coupling capillary electrophoresis (CE) based separation techniques to mass spectrometry creates a powerful platform for analysis of a wide range of biomolecules from complex samples because it combines the high separation efficiency of CE and the sensitivity and selectivity of MS detection. ESI and MALDI, as the most common soft ionization techniques employed for CE and MS coupling, offer distinct advantages for biomolecular characterization. This review is focused primarily on technological advances in combining CE and chip-based CE with ESI and MALDI MS detection in the past five years. Selected applications in the analyses of metabolites, peptides, and proteins with the recently developed CE-MS platforms are also highlighted. PMID:24170529

  17. Individual Particle Analysis of Ambient PM 2.5 Using Advanced Electron Microscopy Techniques

    SciTech Connect

    Gerald J. Keeler; Masako Morishita

    2006-12-31

    The overall goal of this project was to demonstrate a combination of advanced electron microscopy techniques that can be effectively used to identify and characterize individual particles and their sources. Specific techniques to be used include high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM), STEM energy dispersive X-ray spectrometry (EDX), and energy-filtered TEM (EFTEM). A series of ambient PM{sub 2.5} samples were collected in communities in southwestern Detroit, MI (close to multiple combustion sources) and Steubenville, OH (close to several coal fired utility boilers). High-resolution TEM (HRTEM) -imaging showed a series of nano-metal particles including transition metals and elemental composition of individual particles in detail. Submicron and nano-particles with Al, Fe, Ti, Ca, U, V, Cr, Si, Ba, Mn, Ni, K and S were observed and characterized from the samples. Among the identified nano-particles, combinations of Al, Fe, Si, Ca and Ti nano-particles embedded in carbonaceous particles were observed most frequently. These particles showed very similar characteristics of ultrafine coal fly ash particles that were previously reported. By utilizing HAADF-STEM, STEM-EDX, and EF-TEM, this investigation was able to gain information on the size, morphology, structure, and elemental composition of individual nano-particles collected in Detroit and Steubenville. The results showed that the contributions of local combustion sources - including coal fired utilities - to ultrafine particle levels were significant. Although this combination of advanced electron microscopy techniques by itself can not identify source categories, these techniques can be utilized as complementary analytical tools that are capable of providing detailed information on individual particles.

  18. Recent Advances and New Techniques in Visualization of Ultra-short Relativistic Electron Bunches

    SciTech Connect

    Xiang, Dao; /SLAC

    2012-06-05

    Ultrashort electron bunches with rms length of {approx} 1 femtosecond (fs) can be used to generate ultrashort x-ray pulses in FELs that may open up many new regimes in ultrafast sciences. It is also envisioned that ultrashort electron bunches may excite {approx}TeV/m wake fields for plasma wake field acceleration and high field physics studies. Recent success of using 20 pC electron beam to drive an x-ray FEL at LCLS has stimulated world-wide interests in using low charge beam (1 {approx} 20 pC) to generate ultrashort x-ray pulses (0.1 fs {approx} 10 fs) in FELs. Accurate measurement of the length (preferably the temporal profile) of the ultrashort electron bunch is essential for understanding the physics associated with the bunch compression and transportation. However, the shorter and shorter electron bunch greatly challenges the present beam diagnostic methods. In this paper we review the recent advances in the measurement of ultra-short electron bunches. We will focus on several techniques and their variants that provide the state-of-the-art temporal resolution. Methods to further improve the resolution of these techniques and the promise to break the 1 fs time barrier is discussed. We review recent advances in the measurement of ultrashort relativistic electron bunches. We will focus on several techniques and their variants that are capable of breaking the femtosecond time barrier in measurements of ultrashort bunches. Techniques for measuring beam longitudinal phase space as well as the x-ray pulse shape in an x-ray FEL are also discussed.

  19. Methods for Quantification of Soil-Transmitted Helminths in Environmental Media: Current Techniques and Recent Advances.

    PubMed

    Collender, Philip A; Kirby, Amy E; Addiss, David G; Freeman, Matthew C; Remais, Justin V

    2015-12-01

    Limiting the environmental transmission of soil-transmitted helminths (STHs), which infect 1.5 billion people worldwide, will require sensitive, reliable, and cost-effective methods to detect and quantify STHs in the environment. We review the state-of-the-art of STH quantification in soil, biosolids, water, produce, and vegetation with regard to four major methodological issues: environmental sampling; recovery of STHs from environmental matrices; quantification of recovered STHs; and viability assessment of STH ova. We conclude that methods for sampling and recovering STHs require substantial advances to provide reliable measurements for STH control. Recent innovations in the use of automated image identification and developments in molecular genetic assays offer considerable promise for improving quantification and viability assessment. PMID:26440788

  20. Applications of Advanced, Waveform Based AE Techniques for Testing Composite Materials

    NASA Technical Reports Server (NTRS)

    Prosser, William H.

    1996-01-01

    Advanced, waveform based acoustic emission (AE) techniques have been previously used to evaluate damage progression in laboratory tests of composite coupons. In these tests, broad band, high fidelity acoustic sensors were used to detect signals which were then digitized and stored for analysis. Analysis techniques were based on plate mode wave propagation characteristics. This approach, more recently referred to as Modal AE, provides an enhanced capability to discriminate and eliminate noise signals from those generated by damage mechanisms. This technique also allows much more precise source location than conventional, threshold crossing arrival time determination techniques. To apply Modal AE concepts to the interpretation of AE on larger composite structures, the effects of wave propagation over larger distances and through structural complexities must be well characterized and understood. In this research, measurements were made of the attenuation of the extensional and flexural plate mode components of broad band simulated AE signals in large composite panels. As these materials have applications in a cryogenic environment, the effects of cryogenic insulation on the attenuation of plate mode AE signals were also documented.

  1. Advanced grazing-incidence techniques for modern soft-matter materials analysis

    PubMed Central

    Hexemer, Alexander; Müller-Buschbaum, Peter

    2015-01-01

    The complex nano-morphology of modern soft-matter materials is successfully probed with advanced grazing-incidence techniques. Based on grazing-incidence small- and wide-angle X-ray and neutron scattering (GISAXS, GIWAXS, GISANS and GIWANS), new possibilities arise which are discussed with selected examples. Due to instrumental progress, highly interesting possibilities for local structure analysis in this material class arise from the use of micro- and nanometer-sized X-ray beams in micro- or nanofocused GISAXS and GIWAXS experiments. The feasibility of very short data acquisition times down to milliseconds creates exciting possibilities for in situ and in operando GISAXS and GIWAXS studies. Tuning the energy of GISAXS and GIWAXS in the soft X-ray regime and in time-of flight GISANS allows the tailoring of contrast conditions and thereby the probing of more complex morphologies. In addition, recent progress in software packages, useful for data analysis for advanced grazing-incidence techniques, is discussed. PMID:25610632

  2. Advanced grazing-incidence techniques for modern soft-matter materials analysis

    SciTech Connect

    Hexemer, Alexander; Müller-Buschbaum, Peter

    2015-01-01

    The complex nano-morphology of modern soft-matter materials is successfully probed with advanced grazing-incidence techniques. Based on grazing-incidence small- and wide-angle X-ray and neutron scattering (GISAXS, GIWAXS, GISANS and GIWANS), new possibilities arise which are discussed with selected examples. Due to instrumental progress, highly interesting possibilities for local structure analysis in this material class arise from the use of micro- and nanometer-sized X-ray beams in micro- or nanofocused GISAXS and GIWAXS experiments. The feasibility of very short data acquisition times down to milliseconds creates exciting possibilities forin situandin operandoGISAXS and GIWAXS studies. Tuning the energy of GISAXS and GIWAXS in the soft X-ray regime and in time-of flight GISANS allows the tailoring of contrast conditions and thereby the probing of more complex morphologies. In addition, recent progress in software packages, useful for data analysis for advanced grazing-incidence techniques, is discussed.

  3. Advanced grazing-incidence techniques for modern soft-matter materials analysis

    DOE PAGESBeta

    Hexemer, Alexander; Müller-Buschbaum, Peter

    2015-01-01

    The complex nano-morphology of modern soft-matter materials is successfully probed with advanced grazing-incidence techniques. Based on grazing-incidence small- and wide-angle X-ray and neutron scattering (GISAXS, GIWAXS, GISANS and GIWANS), new possibilities arise which are discussed with selected examples. Due to instrumental progress, highly interesting possibilities for local structure analysis in this material class arise from the use of micro- and nanometer-sized X-ray beams in micro- or nanofocused GISAXS and GIWAXS experiments. The feasibility of very short data acquisition times down to milliseconds creates exciting possibilities forin situandin operandoGISAXS and GIWAXS studies. Tuning the energy of GISAXS and GIWAXS in themore »soft X-ray regime and in time-of flight GISANS allows the tailoring of contrast conditions and thereby the probing of more complex morphologies. In addition, recent progress in software packages, useful for data analysis for advanced grazing-incidence techniques, is discussed.« less

  4. Study of solid oxide fuel cell interconnects, protective coatings and advanced physical vapor deposition techniques

    NASA Astrophysics Data System (ADS)

    Gannon, Paul Edward

    High energy conversion efficiency, decreased environmentally-sensitive emissions and fuel flexibility have attracted increasing attention toward solid oxide fuel cell (SOFC) systems for stationary, transportation and portable power generation. Critical durability and cost issues, however, continue to impede wide-spread deployment. Many intermediate temperature (600-800°C) planar SOFC systems employ metallic alloy interconnect components, which physically connect individual fuel cells into electric series, facilitate gas distribution to appropriate SOFC electrode chambers (fuel/anode and oxidant[air]/cathode) and provide SOFC stack mechanical support. These demanding multifunctional requirements challenge commercially-available and inexpensive metallic alloys due to corrosion and related effects. Many ongoing investigations are aimed at enabling inexpensive metallic alloys (via bulk and/or surface modifications) as SOFC interconnects (SOFC(IC)s). In this study, two advanced physical vapor deposition (PVD) techniques: large area filtered vacuum arc deposition (LAFAD), and filtered arc plasma-assisted electron beam PVD (FA-EBPVD) were used to deposit a wide-variety of protective nanocomposite (amorphous/nanocrystalline) ceramic thin-film (<5microm) coatings on commercial and specialty stainless steels with different surface finishes. Both bare and coated steel specimens were subjected to SOFC(IC)-relevant exposures and evaluated using complimentary surface analysis techniques. Significant improvements were observed under simulated SOFC(IC) exposures with many coated specimens at ˜800°C relative to uncoated specimens: stable surface morphology; low area specific resistance (ASR <100mO·cm 2 >1,000 hours); and, dramatically reduced Cr volatility (>30-fold). Analyses and discussions of SOFC(IC) corrosion, advanced PVD processes and protective coating behavior are intended to advance understanding and accelerate the development of durable and commercially-viable SOFC systems.

  5. Molecular Dynamics and Monte Carlo simulations in the microcanonical ensemble: Quantitative comparison and reweighting techniques

    NASA Astrophysics Data System (ADS)

    Schierz, Philipp; Zierenberg, Johannes; Janke, Wolfhard

    2015-10-01

    Molecular Dynamics (MD) and Monte Carlo (MC) simulations are the most popular simulation techniques for many-particle systems. Although they are often applied to similar systems, it is unclear to which extent one has to expect quantitative agreement of the two simulation techniques. In this work, we present a quantitative comparison of MD and MC simulations in the microcanonical ensemble. For three test examples, we study first- and second-order phase transitions with a focus on liquid-gas like transitions. We present MD analysis techniques to compensate for conservation law effects due to linear and angular momentum conservation. Additionally, we apply the weighted histogram analysis method to microcanonical histograms reweighted from MD simulations. By this means, we are able to estimate the density of states from many microcanonical simulations at various total energies. This further allows us to compute estimates of canonical expectation values.

  6. Molecular Rayleigh Scattering Techniques Developed for Measuring Gas Flow Velocity, Density, Temperature, and Turbulence

    NASA Technical Reports Server (NTRS)

    Mielke, Amy F.; Seasholtz, Richard G.; Elam, Kristie A.; Panda, Jayanta

    2005-01-01

    Nonintrusive optical point-wise measurement techniques utilizing the principles of molecular Rayleigh scattering have been developed at the NASA Glenn Research Center to obtain time-averaged information about gas velocity, density, temperature, and turbulence, or dynamic information about gas velocity and density in unseeded flows. These techniques enable measurements that are necessary for validating computational fluid dynamics (CFD) and computational aeroacoustic (CAA) codes. Dynamic measurements allow the calculation of power spectra for the various flow properties. This type of information is currently being used in jet noise studies, correlating sound pressure fluctuations with velocity and density fluctuations to determine noise sources in jets. These nonintrusive techniques are particularly useful in supersonic flows, where seeding the flow with particles is not an option, and where the environment is too harsh for hot-wire measurements.

  7. PREFACE: 16th International workshop on Advanced Computing and Analysis Techniques in physics research (ACAT2014)

    NASA Astrophysics Data System (ADS)

    Fiala, L.; Lokajicek, M.; Tumova, N.

    2015-05-01

    This volume of the IOP Conference Series is dedicated to scientific contributions presented at the 16th International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT 2014), this year the motto was ''bridging disciplines''. The conference took place on September 1-5, 2014, at the Faculty of Civil Engineering, Czech Technical University in Prague, Czech Republic. The 16th edition of ACAT explored the boundaries of computing system architectures, data analysis algorithmics, automatic calculations, and theoretical calculation technologies. It provided a forum for confronting and exchanging ideas among these fields, where new approaches in computing technologies for scientific research were explored and promoted. This year's edition of the workshop brought together over 140 participants from all over the world. The workshop's 16 invited speakers presented key topics on advanced computing and analysis techniques in physics. During the workshop, 60 talks and 40 posters were presented in three tracks: Computing Technology for Physics Research, Data Analysis - Algorithms and Tools, and Computations in Theoretical Physics: Techniques and Methods. The round table enabled discussions on expanding software, knowledge sharing and scientific collaboration in the respective areas. ACAT 2014 was generously sponsored by Western Digital, Brookhaven National Laboratory, Hewlett Packard, DataDirect Networks, M Computers, Bright Computing, Huawei and PDV-Systemhaus. Special appreciations go to the track liaisons Lorenzo Moneta, Axel Naumann and Grigory Rubtsov for their work on the scientific program and the publication preparation. ACAT's IACC would also like to express its gratitude to all referees for their work on making sure the contributions are published in the proceedings. Our thanks extend to the conference liaisons Andrei Kataev and Jerome Lauret who worked with the local contacts and made this conference possible as well as to the program coordinator Federico Carminati and the conference chair Denis Perret-Gallix for their global supervision. Further information on ACAT 2014 can be found at http://www.particle.cz/acat2014

  8. Eigensolution techniques, their applications and the Fisher's information entropy of Tietz-Wei diatomic molecular model

    E-print Network

    B. J. Falaye; K. J. Oyewumi; S. M. Ikhdair; M. Hamzavi

    2014-10-28

    In this study, approximate analytical solution of Schr\\"odinger, Klein-Gordon and Dirac equations under the Tietz-Wei (TW) diatomic molecular potential are represented by using an approximation for the centrifugal term. We have applied three types of eigensolution techniques; the functional analysis approach (FAA), supersymmetry quantum mechanics (SUSYQM) and asymptotic iteration method (AIM) to solve Klein-Gordon Dirac and Schr\\"odinger equations, respectively. The energy eigenvalues and the corresponding eigenfunctions for these three wave equations are obtained and some numerical results and figures are reported. It has been shown that these techniques yielded exactly same results. some expectation values of the TW diatomic molecular potential within the framework of the Hellmann-Feynman theorem (HFT) have been presented. The probability distributions which characterize the quantum-mechanical states of TW diatomic molecular potential are analysed by means of complementary information measures of a probability distribution called the Fishers information entropy. This distribution has been described in terms of Jacobi polynomials, whose characteristics are controlled by the quantum numbers.

  9. Tracking down sulphate-reducing microorganisms by molecular and isotope-labelling techniques

    NASA Astrophysics Data System (ADS)

    Loy, Alexander

    2010-05-01

    Sulphate-reducing microorganisms (SRM) are of great ecological importance for carbon compound degradation and sulphur cycling in many anoxic ecosystems, including marine sediments, peatlands, and oil reservoirs. However, the activity of SRM can result in oil souring and pipeline corrosion and thus is also an economic burden for the oil industry. Molecular diversity surveys based on rRNA genes and dsrAB, genes that encode major subunits of the dissimilatory sulfite reductase, indicate that our view of the natural diversity of SRM (as we know it from cultivation) is far from being complete. This enormous phylogenetic diversity complicates unbiased identification and quantification of SRM by molecular methods such as fluorescence in situ hybridization, real-time PCR or DNA microarrays. Combining these 16S rRNA and dsrAB-based molecular methods with substrate-mediated isotope labelling techniques is a potential solution for identification and functional characterization of yet uncultivated SRM. Using SRM in peatlands as an example, the problems and opportunities of these techniques for diagnosing and monitoring SRM in the environment will be discussed in this talk.

  10. A multiscale modeling technique for bridging molecular dynamics with finite element method

    SciTech Connect

    Lee, Yongchang Basaran, Cemal

    2013-11-15

    In computational mechanics, molecular dynamics (MD) and finite element (FE) analysis are well developed and most popular on nanoscale and macroscale analysis, respectively. MD can very well simulate the atomistic behavior, but cannot simulate macroscale length and time due to computational limits. FE can very well simulate continuum mechanics (CM) problems, but has the limitation of the lack of atomistic level degrees of freedom. Multiscale modeling is an expedient methodology with a potential to connect different levels of modeling such as quantum mechanics, molecular dynamics, and continuum mechanics. This study proposes a new multiscale modeling technique to couple MD with FE. The proposed method relies on weighted average momentum principle. A wave propagation example has been used to illustrate the challenges in coupling MD with FE and to verify the proposed technique. Furthermore, 2-Dimensional problem has also been used to demonstrate how this method would translate into real world applications. -- Highlights: •A weighted averaging momentum method is introduced for bridging molecular dynamics (MD) with finite element (FE) method. •The proposed method shows excellent coupling results in 1-D and 2-D examples. •The proposed method successfully reduces the spurious wave reflection at the border of MD and FE regions. •Big advantages of the proposed method are simplicity and inexpensive computational cost of multiscale analysis.

  11. Choroid plexus papillomas: advances in molecular biology and understanding of tumorigenesis

    PubMed Central

    Safaee, Michael; Oh, Michael C.; Bloch, Orin; Sun, Matthew Z.; Kaur, Gurvinder; Auguste, Kurtis I.; Tihan, Tarik; Parsa, Andrew T.

    2013-01-01

    Choroid plexus papillomas are rare, benign tumors originating from the choroid plexus. Although generally found within the ventricular system, they can arise ectopically in the brain parenchyma or disseminate throughout the neuraxis. We sought to review recent advances in our understanding of the molecular biology and oncogenic pathways associated with this disease. A comprehensive PubMed literature review was conducted to identify manuscripts discussing the clinical, molecular, and genetic features of choroid plexus papillomas. Articles concerning diagnosis, treatment, and long-term patient outcomes were also reviewed. The introduction of atypical choroid plexus papilloma as a distinct entity has increased the need for accurate histopathologic diagnosis. Advances in immunohistochemical staining have improved our ability to differentiate choroid plexus papillomas from other intracranial tumors or metastatic lesions using combinations of key markers and mitotic indices. Recent findings have implicated Notch3 signaling, the transcription factor TWIST1, platelet-derived growth factor receptor, and the tumor necrosis factor–related apoptosis-inducing ligand pathway in choroid plexus papilloma tumorigenesis. A combination of commonly occurring chromosomal duplications and deletions has also been identified. Surgical resection remains the standard of care, although chemotherapy and radiotherapy may be considered for recurrent or metastatic lesions. While generally considered benign, these tumors possess a complex biology that sheds insight into other choroid plexus tumors, particularly malignant choroid plexus carcinomas. Improving our understanding of the molecular biology, genetics, and oncogenic pathways associated with this tumor will allow for the development of targeted therapies and improved outcomes for patients with this disease. PMID:23172371

  12. Advancing Molecular-Guided Surgery through probe development and testing in a moderate cost evaluation pipeline

    PubMed Central

    Pogue, Brian W; Paulsen, Keith D; Hull, Sally M.; Samkoe, Kimberly S.; Gunn, Jason; Hoopes, Jack; Roberts, David W.; Strong, Theresa V.; Draney, Daniel; Feldwisch, Joachim

    2015-01-01

    Molecular guided oncology surgery has the potential to transform the way decisions about resection are done, and can be critically important in areas such as neurosurgery where the margins of tumor relative to critical normal tissues are not readily apparent from visual or palpable guidance. Yet there are major financial barriers to advancing agents into clinical trials with commercial backing. We observe that development of these agents in the standard biological therapeutic paradigm is not viable, due to the high up front financial investment needed and the limitations in the revenue models of contrast agents for imaging. The hypothesized solution to this problem is to develop small molecular biologicals tagged with an established fluorescent reporter, through the chemical agent approval pathway, targeting a phase 0 trials initially, such that the initial startup phase can be completely funded by a single NIH grant. In this way, fast trials can be completed to de-risk the development pipeline, and advance the idea of fluorescence-guided surgery (FGS) reporters into human testing. As with biological therapies the potential successes of each agent are still moderate, but this process will allow the field to advance in a more stable and productive manner, rather than relying upon isolated molecules developed at high cost and risk. The pathway proposed and tested here uses peptide synthesis of an epidermal growth factor receptor (EGFR)-binding Affibody molecules, uniquely conjugated to IRDye 800CW, developed and tested in academic and industrial laboratories with well-established records for GMP production, fill & finish, toxicity testing, and early phase clinical trials with image guidance. PMID:25914500

  13. Advancing molecular-guided surgery through probe development and testing in a moderate cost evaluation pipeline

    NASA Astrophysics Data System (ADS)

    Pogue, Brian W.; Paulsen, Keith D.; Hull, Sally M.; Samkoe, Kimberley S.; Gunn, Jason; Hoopes, Jack; Roberts, David W.; Strong, Theresa V.; Draney, Daniel; Feldwisch, Joachim

    2015-03-01

    Molecular guided oncology surgery has the potential to transform the way decisions about resection are done, and can be critically important in areas such as neurosurgery where the margins of tumor relative to critical normal tissues are not readily apparent from visual or palpable guidance. Yet there are major financial barriers to advancing agents into clinical trials with commercial backing. We observe that development of these agents in the standard biological therapeutic paradigm is not viable, due to the high up front financial investment needed and the limitations in the revenue models of contrast agents for imaging. The hypothesized solution to this problem is to develop small molecular biologicals tagged with an established fluorescent reporter, through the chemical agent approval pathway, targeting a phase 0 trials initially, such that the initial startup phase can be completely funded by a single NIH grant. In this way, fast trials can be completed to de-risk the development pipeline, and advance the idea of fluorescence-guided surgery (FGS) reporters into human testing. As with biological therapies the potential successes of each agent are still moderate, but this process will allow the field to advance in a more stable and productive manner, rather than relying upon isolated molecules developed at high cost and risk. The pathway proposed and tested here uses peptide synthesis of an epidermal growth factor receptor (EGFR)-binding Affibody molecules, uniquely conjugated to IRDye 800CW, developed and tested in academic and industrial laboratories with well-established records for GMP production, fill and finish, toxicity testing, and early phase clinical trials with image guidance.

  14. Abstract--Software modules of an advanced vehicle can be updated using Remote Software Upload (RSU) techniques. The

    E-print Network

    Mahmud, Syed Masud

    Abstract-- Software modules of an advanced vehicle can be updated using Remote Software Upload (RSU) techniques. The RSU employs infrastructure-based wireless communication technique where the software supplier sends the software to the targeted vehicle via a roadside Base Station (BS). However, security

  15. Biosynthesis of polyunsaturated fatty acids in marine invertebrates: recent advances in molecular mechanisms.

    PubMed

    Monroig, Óscar; Tocher, Douglas R; Navarro, Juan C

    2013-10-01

    Virtually all polyunsaturated fatty acids (PUFA) originate from primary producers but can be modified by bioconversions as they pass up the food chain in a process termed trophic upgrading. Therefore, although the main primary producers of PUFA in the marine environment are microalgae, higher trophic levels have metabolic pathways that can produce novel and unique PUFA. However, little is known about the pathways of PUFA biosynthesis and metabolism in the levels between primary producers and fish that are largely filled by invertebrates. It has become increasingly apparent that, in addition to trophic upgrading, de novo synthesis of PUFA is possible in some lower animals. The unequivocal identification of PUFA biosynthetic pathways in many invertebrates is complicated by the presence of other organisms within them. These organisms include bacteria and algae with PUFA biosynthesis pathways, and range from intestinal flora to symbiotic relationships that can involve PUFA translocation to host organisms. This emphasizes the importance of studying biosynthetic pathways at a molecular level, and the continual expansion of genomic resources and advances in molecular analysis is facilitating this. The present paper highlights recent research into the molecular and biochemical mechanisms of PUFA biosynthesis in marine invertebrates, particularly focusing on cephalopod molluscs. PMID:24152561

  16. Biosynthesis of Polyunsaturated Fatty Acids in Marine Invertebrates: Recent Advances in Molecular Mechanisms

    PubMed Central

    Monroig, Óscar; Tocher, Douglas R.; Navarro, Juan C.

    2013-01-01

    Virtually all polyunsaturated fatty acids (PUFA) originate from primary producers but can be modified by bioconversions as they pass up the food chain in a process termed trophic upgrading. Therefore, although the main primary producers of PUFA in the marine environment are microalgae, higher trophic levels have metabolic pathways that can produce novel and unique PUFA. However, little is known about the pathways of PUFA biosynthesis and metabolism in the levels between primary producers and fish that are largely filled by invertebrates. It has become increasingly apparent that, in addition to trophic upgrading, de novo synthesis of PUFA is possible in some lower animals. The unequivocal identification of PUFA biosynthetic pathways in many invertebrates is complicated by the presence of other organisms within them. These organisms include bacteria and algae with PUFA biosynthesis pathways, and range from intestinal flora to symbiotic relationships that can involve PUFA translocation to host organisms. This emphasizes the importance of studying biosynthetic pathways at a molecular level, and the continual expansion of genomic resources and advances in molecular analysis is facilitating this. The present paper highlights recent research into the molecular and biochemical mechanisms of PUFA biosynthesis in marine invertebrates, particularly focusing on cephalopod molluscs. PMID:24152561

  17. Molecular Profiling-Selected Therapy for Treatment of Advanced Pancreaticobiliary Cancer: A Retrospective Multicenter Study

    PubMed Central

    Epelbaum, Ron; Shacham-Shmueli, Einat; Klein, Baruch; Agbarya, Abed; Brenner, Baruch; Brenner, Ronen; Gez, Eliahu; Golan, Talia; Hubert, Ayala; Purim, Ofer; Temper, Mark; Tepper, Ella; Voss, Andreas; Russell, Kenneth; Dvir, Addie; Soussan-Gutman, Lior; Stemmer, Salomon M.; Geva, Ravit

    2015-01-01

    This multicenter cohort study assessed the impact of molecular profiling (MP) on advanced pancreaticobiliary cancer (PBC). The study included 30 patients treated with MP-guided therapy after failing ?1 therapy for advanced PBC. Treatment was considered as having benefit for the patient if the ratio between the longest progression-free survival (PFS) on MP-guided therapy and the PFS on the last therapy before MP was ?1.3. The null hypothesis was that ?15% of patients gain such benefit. Overall, ?1 actionable (i.e., predictive of response to specific therapies) biomarker was identified/patient. Immunohistochemistry (the most commonly used method for guiding treatment decisions) identified 1–6 (median: 4) actionable biomarkers per patient. After MP, patients received 1–4 (median: 1) regimens/patient (most commonly, FOLFIRI/XELIRI). In a decision-impact analysis, of the 27 patients for whom treatment decisions before MP were available, 74.1% experienced a treatment decision change in the first line after MP. Twenty-four patients were evaluable for clinical outcome analysis; in 37.5%, the PFS ratio was ?1.3. In one-sided exact binomial test versus the null hypothesis, P = 0.0015; therefore, the null hypothesis was rejected. In conclusion, our analysis demonstrated the feasibility, clinical decision impact, and potential clinical benefits of MP-guided therapy in advanced PBC. PMID:26161408

  18. Molecular-Based Optical Measurement Techniques for Transition and Turbulence in High-Speed Flow

    NASA Technical Reports Server (NTRS)

    Bathel, Brett F.; Danehy, Paul M.; Cutler, Andrew D.

    2013-01-01

    High-speed laminar-to-turbulent transition and turbulence affect the control of flight vehicles, the heat transfer rate to a flight vehicle's surface, the material selected to protect such vehicles from high heating loads, the ultimate weight of a flight vehicle due to the presence of thermal protection systems, the efficiency of fuel-air mixing processes in high-speed combustion applications, etc. Gaining a fundamental understanding of the physical mechanisms involved in the transition process will lead to the development of predictive capabilities that can identify transition location and its impact on parameters like surface heating. Currently, there is no general theory that can completely describe the transition-to-turbulence process. However, transition research has led to the identification of the predominant pathways by which this process occurs. For a truly physics-based model of transition to be developed, the individual stages in the paths leading to the onset of fully turbulent flow must be well understood. This requires that each pathway be computationally modeled and experimentally characterized and validated. This may also lead to the discovery of new physical pathways. This document is intended to describe molecular based measurement techniques that have been developed, addressing the needs of the high-speed transition-to-turbulence and high-speed turbulence research fields. In particular, we focus on techniques that have either been used to study high speed transition and turbulence or techniques that show promise for studying these flows. This review is not exhaustive. In addition to the probe-based techniques described in the previous paragraph, several other classes of measurement techniques that are, or could be, used to study high speed transition and turbulence are excluded from this manuscript. For example, surface measurement techniques such as pressure and temperature paint, phosphor thermography, skin friction measurements and photogrammetry (for model attitude and deformation measurement) are excluded to limit the scope of this report. Other physical probes such as heat flux gauges, total temperature probes are also excluded. We further exclude measurement techniques that require particle seeding though particle based methods may still be useful in many high speed flow applications. This manuscript details some of the more widely used molecular-based measurement techniques for studying transition and turbulence: laser-induced fluorescence (LIF), Rayleigh and Raman Scattering and coherent anti-Stokes Raman scattering (CARS). These techniques are emphasized, in part, because of the prior experience of the authors. Additional molecular based techniques are described, albeit in less detail. Where possible, an effort is made to compare the relative advantages and disadvantages of the various measurement techniques, although these comparisons can be subjective views of the authors. Finally, the manuscript concludes by evaluating the different measurement techniques in view of the precision requirements described in this chapter. Additional requirements and considerations are discussed to assist with choosing an optical measurement technique for a given application.

  19. Measurements of the subcriticality using advanced technique of shooting source during operation of NPP reactors

    NASA Astrophysics Data System (ADS)

    Lebedev, G. V.; Petrov, V. V.; Bobylyov, V. T.; Butov, R. I.; Zhukov, A. M.; Sladkov, A. A.

    2014-12-01

    According to the rules of nuclear safety, the measurements of the subcriticality of reactors should be carried out in the process of performing nuclear hazardous operations. An advanced technique of shooting source of neutrons is proposed to meet this requirement. As such a source, a pulsed neutron source (PNS) is used. In order to realize this technique, it is recommended to enable a PNS with a frequency of 1-20 Hz. The PNS is stopped after achieving a steady-state (on average) number of neutrons in the reactor volume. The change in the number of neutrons in the reactor volume is measured in time with an interval of discreteness of ˜0.1 s. The results of these measurements with the application of a system of point-kinetics equations are used in order to calculate the sought subcriticality. The basic idea of the proposed technique used to measure the subcriticality is elaborated in a series of experiments on the Kvant assembly. The conditions which should be implemented in order to obtain a positive result of measurements are formulated. A block diagram of the basic version of the experimental setup is presented, whose main element is a pulsed neutron generator.

  20. Measurements of the subcriticality using advanced technique of shooting source during operation of NPP reactors

    SciTech Connect

    Lebedev, G. V. Petrov, V. V.; Bobylyov, V. T.; Butov, R. I.; Zhukov, A. M.; Sladkov, A. A.

    2014-12-15

    According to the rules of nuclear safety, the measurements of the subcriticality of reactors should be carried out in the process of performing nuclear hazardous operations. An advanced technique of shooting source of neutrons is proposed to meet this requirement. As such a source, a pulsed neutron source (PNS) is used. In order to realize this technique, it is recommended to enable a PNS with a frequency of 1–20 Hz. The PNS is stopped after achieving a steady-state (on average) number of neutrons in the reactor volume. The change in the number of neutrons in the reactor volume is measured in time with an interval of discreteness of ?0.1 s. The results of these measurements with the application of a system of point-kinetics equations are used in order to calculate the sought subcriticality. The basic idea of the proposed technique used to measure the subcriticality is elaborated in a series of experiments on the Kvant assembly. The conditions which should be implemented in order to obtain a positive result of measurements are formulated. A block diagram of the basic version of the experimental setup is presented, whose main element is a pulsed neutron generator.

  1. Technique for Elimination of Excited States from Atomic and Molecular Ion Beams

    NASA Astrophysics Data System (ADS)

    Vane, C. R.; Bannister, M. E.; Havener, C. C.; Liu, Yuan

    2012-06-01

    Fundamental interactions of atomic and molecular ions with electrons, neutral atoms and molecules, surfaces, and photons play major roles in many important plasma and chemical environments. Achieving a detailed understanding of these interactions is often complicated by the presence of uncharacterized populations of electronic or vibrational excited states, especially in making direct comparisons with theoretical predictions problematic. We are developing experimental techniques for reducing or eliminating ion source-generated excited states in atomic and molecular ion beams using a gas-filled RF quadrupole (RFQ) ion cooler, through natural radiative cooling during ion transit, and by preferential quenching in charge transfer collisions with selected buffer gases. Technical details and progress toward these goals will be presented. Research sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U. S. Department of Energy.

  2. Techniques for Evaluation of LAMP Amplicons and their Applications in Molecular Biology.

    PubMed

    Dehghan Esmatabadi, Mohammad Javad; Bozorgmehr, Ali; Motalebzadeh, Hesam; Bodaghabadi, Narges; Farhangi, Baharak; Babashah, Sadegh; Sadeghizadeh, Majid

    2015-01-01

    Loop-mediated isothermal amplification (LAMP) developed by Notomi et al. (2000) has made it possible to amplify DNA with high specificity, efficiency and rapidity under isothermal conditions. The ultimate products of LAMP are stem-loop structures with several inverted repeats of the target sequence and cauliflower-like patterns with multiple loops shaped by annealing between every other inverted repeats of the amplified target in the similar strand. Because the amplification process in LAMP is achieved by using four to six distinct primers, it is expected to amplify the target region with high selectivity. However, evaluation of reaction accuracy or quantitative inspection make it necessary to append other procedures to scrutinize the amplified products. Hitherto, various techniques such as turbidity assessment in the reaction vessel, post-reaction agarose gel electrophoresis, use of intercalating fluorescent dyes, real-time turbidimetry, addition of cationic polymers to the reaction mixture, polyacrylamide gel-based microchambers, lateral flow dipsticks, fluorescence resonance energy transfer (FRET), enzyme-linked immunosorbent assays and nanoparticle-based colorimetric tests have been utilized for this purpose. In this paper, we reviewed the best-known techniques for evaluation of LAMP amplicons and their applications in molecular biology beside their advantages and deficiencies. Regarding the properties of each technique, the development of innovative prompt, cost-effective and precise molecular detection methods for application in the broad field of cancer research may be feasible. PMID:26625736

  3. Coulomb-explosion technique for determining geometrical structures of molecular ions

    SciTech Connect

    Gemmell, D.S.

    1981-01-01

    Traditional experimental techniques (e.g. studies on photon absorption or emission) for determining the sterochemical structures of neutral molecules are extremeley difficult to apply to molecular ions because of problems in obtaining a sufficient spatial density of the ions to be studied. Recent high-resolution measurements on the energy and angle distributions of the fragments produced when fast (MeV) molecular-ion beams from an electrostatic accelerator dissociate (Coulomb explode) in thin foils and in gases, offer promising possibilities for deducing the sterochemical structures of the molecular ions constituting the incident beams. Bond lengths have been determined in this way for several diatomic projectiles (H/sub 2//sup +/, HeH/sup +/, CH/sup +/, NH/sup +/, OH/sup +/, N/sub 2//sup +/, O/sub 2//sup +/, etc.) with an accuracy of approx. 0.01 A. H/sub 3//sup +/ has been demonstrated (for the first time) to be equilateral triangular and the interproton distance measured. Measurements on single fragments from CO/sub 2//sup +/, N/sub 2/O/sup +/, C/sub 3/H/sub 3//sup +/, and CH/sub n//sup +/ have revealed the gross structures of the projectiles. An apparatus has recently been constructed at Argonne to permit precise measurements on fragments in coincidence. The apparatus has been tested on a known structure (OH/sub 2//sup +/). The O-H bond length was found to be 1.0 +- 0.04 A and the H-O-H bond angle was measured as 110 --- 2/sup 0/. These values are in excellent agreement with those found in optical experiments (0.999 A and 110.5/sup 0/). This Coulomb explosion technique can be expected to be refined in accuracy and to be extended to a wide range of molecular ions whose structures are inaccessible by other means.

  4. Contemporary molecular tools in microbial ecology and their application to advancing biotechnology.

    PubMed

    Rashid, Mamoon; Stingl, Ulrich

    2015-12-01

    Novel methods in microbial ecology are revolutionizing our understanding of the structure and function of microbes in the environment, but concomitant advances in applications of these tools to biotechnology are mostly lagging behind. After more than a century of efforts to improve microbial culturing techniques, about 70-80% of microbial diversity - recently called the "microbial dark matter" - remains uncultured. In early attempts to identify and sample these so far uncultured taxonomic lineages, methods that amplify and sequence ribosomal RNA genes were extensively used. Recent developments in cell separation techniques, DNA amplification, and high-throughput DNA sequencing platforms have now made the discovery of genes/genomes of uncultured microorganisms from different environments possible through the use of metagenomic techniques and single-cell genomics. When used synergistically, these metagenomic and single-cell techniques create a powerful tool to study microbial diversity. These genomics techniques have already been successfully exploited to identify sources for i) novel enzymes or natural products for biotechnology applications, ii) novel genes from extremophiles, and iii) whole genomes or operons from uncultured microbes. More can be done to utilize these tools more efficiently in biotechnology. PMID:26409315

  5. Advances in functional X-ray imaging techniques and contrast agents

    PubMed Central

    Chen, Hongyu; Rogalski, Melissa M.

    2012-01-01

    X-rays have been used for non-invasive high-resolution imaging of thick biological specimens since their discovery in 1895. They are widely used for structural imaging of bone, metal implants, and cavities in soft tissue. Recently, a number of new contrast methodologies have emerged which are expanding X-ray’s biomedical applications to functional as well as structural imaging. These techniques are promising to dramatically improve our ability to study in situ biochemistry and disease pathology. In this review, we discuss how X-ray absorption, X-ray fluorescence, and X-ray excited optical luminescence can be used for physiological, elemental, and molecular imaging of vasculature, tumours, pharmaceutical distribution, and the surface of implants. Imaging of endogenous elements, exogenous labels, and analytes detected with optical indicators will be discussed. PMID:22962667

  6. Visualisation of Ecohydrological Processes and Relationships for Teaching Using Advanced Techniques

    NASA Astrophysics Data System (ADS)

    Guan, H.; Wang, H.; Gutierrez-Jurado, H. A.; Yang, Y.; Deng, Z.

    2014-12-01

    Ecohydrology is an emerging discipline with a rapid research growth. This calls for enhancing ecohydrology education in both undergraduate and postgraduate levels. In other hydrology disciplines, hydrological processes are commonly observed in environments (e.g. streamflow, infiltration) or easily demonstrated in labs (e.g. Darcy's column). It is relatively difficult to demonstrate ecohydrological concepts and processes (e.g. soil-vegetation water relationship) in teaching. In this presentation, we report examples of using some advanced techniques to illustrate ecohydrological concepts, relationships, and processes, with measurements based on a native vegetation catchment in South Australia. They include LIDAR images showing the relationship between topography-control hdyroclimatic conditions and vegetation distribution, electrical resistivity tomography derived images showing stem structures, continuous stem water potential monitoring showing diurnal variations of plant water status, root zone moisture depletion during dry spells, and responses to precipitation inputs, and incorporating sapflow measurements to demonstrate environmental stress on plant stomatal behaviours.

  7. Planning and scheduling the Hubble Space Telescope: Practical application of advanced techniques

    NASA Technical Reports Server (NTRS)

    Miller, Glenn E.

    1994-01-01

    NASA's Hubble Space Telescope (HST) is a major astronomical facility that was launched in April, 1990. In late 1993, the first of several planned servicing missions refurbished the telescope, including corrections for a manufacturing flaw in the primary mirror. Orbiting above the distorting effects of the Earth's atmosphere, the HST provides an unrivaled combination of sensitivity, spectral coverage and angular resolution. The HST is arguably the most complex scientific observatory ever constructed and effective use of this valuable resource required novel approaches to astronomical observation and the development of advanced software systems including techniques to represent scheduling preferences and constraints, a constraint satisfaction problem (CSP) based scheduler and a rule based planning system. This paper presents a discussion of these systems and the lessons learned from operational experience.

  8. 75 FR 44015 - Certain Semiconductor Products Made by Advanced Lithography Techniques and Products Containing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ...Inv. No. 337-TA-729] Certain Semiconductor Products Made by Advanced Lithography...States after importation of certain semiconductor products made by advanced lithography...States after importation of certain semiconductor products made by advanced...

  9. Recent advances on techniques and theories of feedforward networks with supervised learning

    NASA Astrophysics Data System (ADS)

    Xu, Lei; Klasa, Stan

    1992-07-01

    The rediscovery and popularization of the back propagation training technique for multilayer perceptrons as well as the invention of the Boltzmann Machine learning algorithm has given a new boost to the study of supervised learning networks. In recent years, besides the widely spread applications and the various further improvements of the classical back propagation technique, many new supervised learning models, techniques as well as theories, have also been proposed in a vast number of publications. This paper tries to give a rather systematical review on the recent advances on supervised learning techniques and theories for static feedforward networks. We summarize a great number of developments into four aspects: (1) Various improvements and variants made on the classical back propagation techniques for multilayer (static) perceptron nets, for speeding up training, avoiding local minima, increasing the generalization ability, as well as for many other interesting purposes. (2) A number of other learning methods for training multilayer (static) perceptron, such as derivative estimation by perturbation, direct weight update by perturbation, genetic algorithms, recursive least square estimate and extended Kalman filter, linear programming, the policy of fixing one layer while updating another, constructing networks by converting decision tree classifiers, and others. (3) Various other feedforward models which are also able to implement function approximation, probability density estimation and classification, including various models of basis function expansion (e.g., radial basis functions, restricted coulomb energy, multivariate adaptive regression splines, trigonometric and polynomial bases, projection pursuit, basis function tree, and may others), and several other supervised learning models. (4) Models with complex structures, e.g., modular architecture, hierarchy architecture, and others. (5) A number of theoretical issues involving the universal approximation of continuous functions, best approximation ability, learnability, capability, generalization ability, and the relations between these abilities to the number of layers in a network, the number of the neurons needed, hidden neurons, as well as the number of training samples. Altogether, we try to give a global picture of the present state of supervised learning techniques and theories for training static feedforward networks.

  10. Molecular motions in lipid bilayers studied by the neutron backscattering technique

    E-print Network

    Maikel C. Rheinstädter; Tilo Seydel; Franz Demmel; Tim Salditt

    2005-04-17

    We report a high energy-resolution neutron backscattering study to investigate slow motions on nanosecond time scales in highly oriented solid supported phospholipid bilayers of the model system DMPC -d54 (deuterated 1,2-dimyristoyl-sn-glycero-3-phoshatidylcholine), hydrated with heavy water. This technique allows to discriminate the onset of mobility at different length scales for the different molecular components, as e.g.\\@ the lipid acyl-chains and the hydration water in between the membrane stacks, respectively, and provides a benchmark test regarding the feasibility of neutron backscattering investigations on these sample systems. We discuss freezing of the lipid acyl-chains, as observed by this technique, and observe a second freezing transition which we attribute to the hydration water.

  11. Gender identification of Grasshopper Sparrows comparing behavioral, morphological, and molecular techniques

    USGS Publications Warehouse

    Ammer, F.K.; Wood, P.B.; McPherson, R.J.

    2008-01-01

    Correct gender identification in monomorphic species is often difficult especially if males and females do not display obvious behavioral and breeding differences. We compared gender specific morphology and behavior with recently developed DNA techniques for gender identification in the monomorphic Grasshopper Sparrow (Ammodramus savannarum). Gender was ascertained with DNA in 213 individuals using the 2550F/2718R primer set and 3% agarose gel electrophoresis. Field observations using behavior and breeding characteristics to identify gender matched DNA analyses with 100% accuracy for adult males and females. Gender was identified with DNA for all captured juveniles that did not display gender specific traits or behaviors in the field. The molecular techniques used offered a high level of accuracy and may be useful in studies of dispersal mechanisms and winter assemblage composition in monomorphic species.

  12. Advancement of polarizable force field and its use for molecular modeling and design.

    PubMed

    Xu, Peijun; Wang, Jinguang; Xu, Yong; Chu, Huiying; Liu, Jiahui; Zhao, Meixia; Zhang, Depeng; Mao, Yingchen; Li, Beibei; Ding, Yang; Li, Guohui

    2015-01-01

    The most important requirement of biomolecular modeling is to deal with electrostatic energies. The electrostatic polarizability is an important part of electrostatic interaction for simulation systems. However, AMBER, CHARMM, OPLS, GROMOS, MMFF force fields etc. used in the past mostly apply fixed atomic center point charge to describe electrostatic energies, and are not sufficient for considering the influence of the electrostatic polarization. The emergence of polarizable force fields has solved this problem. In recent years, quickly developed polarizable force fields have involved a lot of fields. The chapter relating to polarizable force fields spread over several aspects. Firstly, we reviewed the history of the classical force fields and compared with polarizable force fields to elucidate the advancements of polarizable force fields. Secondly, it is introduced that the application of polarizable force fields to small molecules and biological macromolecules simulation, including molecular design. Finally, a brief development trend and perspective is given on rapidly growing polarizable force fields. PMID:25387957

  13. Molecularly targeted therapies for advanced or metastatic non-small-cell lung carcinoma

    PubMed Central

    Bayraktar, Soley; Rocha-Lima, Caio M

    2013-01-01

    Non-small-cell lung cancer (NSCLC) remains the leading cause of cancer-related death in both men and women in the United States. Platinum-based doublet chemotherapy has been a standard for patients with advanced stage disease. Improvements in overall survival and quality of life have been modest. Improved knowledge of the aberrant molecular signaling pathways found in NSCLC has led to the development of biomarkers with associated targeted therapeutics, thus changing the treatment paradigm for many NSCLC patients. In this review, we present a summary of many of the currently investigated biologic targets in NSCLC, discuss their current clinical trial status, and also discuss the potential for development of other targeted agents. PMID:23696960

  14. Advancements in sensing and perception using structured lighting techniques :an LDRD final report.

    SciTech Connect

    Novick, David Keith; Padilla, Denise D.; Davidson, Patrick A. Jr.; Carlson, Jeffrey J.

    2005-09-01

    This report summarizes the analytical and experimental efforts for the Laboratory Directed Research and Development (LDRD) project entitled ''Advancements in Sensing and Perception using Structured Lighting Techniques''. There is an ever-increasing need for robust, autonomous ground vehicles for counterterrorism and defense missions. Although there has been nearly 30 years of government-sponsored research, it is undisputed that significant advancements in sensing and perception are necessary. We developed an innovative, advanced sensing technology for national security missions serving the Department of Energy, the Department of Defense, and other government agencies. The principal goal of this project was to develop an eye-safe, robust, low-cost, lightweight, 3D structured lighting sensor for use in broad daylight outdoor applications. The market for this technology is wide open due to the unavailability of such a sensor. Currently available laser scanners are slow, bulky and heavy, expensive, fragile, short-range, sensitive to vibration (highly problematic for moving platforms), and unreliable for outdoor use in bright sunlight conditions. Eye-safety issues are a primary concern for currently available laser-based sensors. Passive, stereo-imaging sensors are available for 3D sensing but suffer from several limitations : computationally intensive, require a lighted environment (natural or man-made light source), and don't work for many scenes or regions lacking texture or with ambiguous texture. Our approach leveraged from the advanced capabilities of modern CCD camera technology and Center 6600's expertise in 3D world modeling, mapping, and analysis, using structured lighting. We have a diverse customer base for indoor mapping applications and this research extends our current technology's lifecycle and opens a new market base for outdoor 3D mapping. Applications include precision mapping, autonomous navigation, dexterous manipulation, surveillance and reconnaissance, part inspection, geometric modeling, laser-based 3D volumetric imaging, simultaneous localization and mapping (SLAM), aiding first responders, and supporting soldiers with helmet-mounted LADAR for 3D mapping in urban-environment scenarios. The technology developed in this LDRD overcomes the limitations of current laser-based 3D sensors and contributes to the realization of intelligent machine systems reducing manpower need.

  15. Advanced Modeling Techniques to Study Anthropogenic Influences on Atmospheric Chemical Budgets

    NASA Technical Reports Server (NTRS)

    Mathur, Rohit

    1997-01-01

    This research work is a collaborative effort between research groups at MCNC and the University of North Carolina at Chapel Hill. The overall objective of this research is to improve the level of understanding of the processes that determine the budgets of chemically and radiatively active compounds in the atmosphere through development and application of advanced methods for calculating the chemical change in atmospheric models. The research performed during the second year of this project focused on four major aspects: (1) The continued development and refinement of multiscale modeling techniques to address the issue of the disparate scales of the physico-chemical processes that govern the fate of atmospheric pollutants; (2) Development and application of analysis methods utilizing process and mass balance techniques to increase the interpretive powers of atmospheric models and to aid in complementary analysis of model predictions and observations; (3) Development of meteorological and emission inputs for initial application of the chemistry/transport model over the north Atlantic region; and, (4) The continued development and implementation of a totally new adaptive chemistry representation that changes the details of what is represented as the underlying conditions change.

  16. Applying Model Abstraction Techniques to the Advanced Low Altitude Radar Model (ALARM)

    NASA Astrophysics Data System (ADS)

    Plotz, Gary; Dibble, Serena

    2002-10-01

    Modeling of real systems relies on the arduous task of describing the physical phenomena in terms of mathematical models, which often require excessive amounts of computation time when used in simulations. In the last few years there has been a growing acceptance of model abstraction whose emphasis rests on the development of more manageable models. Abstraction refers to the intelligent capture of the essence of the behavior of a model, without all the details. In the past, model abstraction techniques have been applied to complex models, such as Advanced Low Altitude Radar Model (ALARM) to simplify analysis. The scope of this effort is to apply model abstraction techniques to ALARM; a DoD prototype radar model for simulating the volume detection capability of low flying targets within a digitally simulated environment. Due to the complexity of these models, it is difficult to capture and assess the relationship between the model parameters and the performance of the simulation. Under this effort, ALARM parameters were modified and/or deleted and the impact on the simulation run time assessed. In addition, several meta-models were developed and used to assess the impact of ALARM parameters on the simulation run time. This report establishes a baseline for ALARM from which additional meta-models can be compared and analyzed.

  17. Applying model abstraction techniques to the Advanced Low Altitude Radar Model (ALARM)

    NASA Astrophysics Data System (ADS)

    Plotz, Gary A.; Dibble, Serena

    2002-07-01

    Modeling of real systems relies on the arduous task of describing the physical phenomena in terms of mathematical models, which often require excessive amounts of computation time when used in simulations. In the last few years there has been a growing acceptance of model abstraction whose emphasis rests on the development of more manageable models. Abstraction refers to the intelligent capture of the essence of the behavior of a model, without all the details. In the past, model abstraction techniques have been applied to complex models, such as Advanced Low Altitude Radar Model (ALARM) to simplify analysis. The scope of this effort is to apply model abstraction techniques to ALARM; a DoD prototype radar model for simulating the volume detection capability of low flying targets within a digitally simulated environment. Due to the complexity of these models it is difficult to capture and assess the relationship between the model parameters and the performance of the simulation. Under this effort ALARM parameters were modified and/or deleted and the impact on the simulation run time assessed. In addition, several meta-models were developed and used to assess the impact of ALARM parameters on the simulation run time. This paper establishes a baseline for ALARM from which additional meta-models can be compared and analyzed.

  18. Investigation to advance prediction techniques of the low-speed aerodynamics of V/STOL aircraft

    NASA Technical Reports Server (NTRS)

    Maskew, B.; Strash, D.; Nathman, J.; Dvorak, F. A.

    1985-01-01

    A computer program, VSAERO, has been applied to a number of V/STOL configurations with a view to advancing prediction techniques for the low-speed aerodynamic characteristics. The program couples a low-order panel method with surface streamline calculation and integral boundary layer procedures. The panel method--which uses piecewise constant source and doublet panels-includes an iterative procedure for wake shape and models boundary layer displacement effect using the source transpiration technique. Certain improvements to a basic vortex tube jet model were installed in the code prior to evaluation. Very promising results were obtained for surface pressures near a jet issuing at 90 deg from a flat plate. A solid core model was used in the initial part of the jet with a simple entrainment model. Preliminary representation of the downstream separation zone significantly improve the correlation. The program accurately predicted the pressure distribution inside the inlet on the Grumman 698-411 design at a range of flight conditions. Furthermore, coupled viscous/potential flow calculations gave very close correlation with experimentally determined operational boundaries dictated by the onset of separation inside the inlet. Experimentally observed degradation of these operational boundaries between nacelle-alone tests and tests on the full configuration were also indicated by the calculation. Application of the program to the General Dynamics STOL fighter design were equally encouraging. Very close agreement was observed between experiment and calculation for the effects of power on pressure distribution, lift and lift curve slope.

  19. STED-FLCS: An Advanced Tool to Reveal Spatiotemporal Heterogeneity of Molecular Membrane Dynamics.

    PubMed

    Vicidomini, Giuseppe; Ta, Haisen; Honigmann, Alf; Mueller, Veronika; Clausen, Mathias P; Waithe, Dominic; Galiani, Silvia; Sezgin, Erdinc; Diaspro, Alberto; Hell, Stefan W; Eggeling, Christian

    2015-09-01

    Heterogeneous diffusion dynamics of molecules play an important role in many cellular signaling events, such as of lipids in plasma membrane bioactivity. However, these dynamics can often only be visualized by single-molecule and super-resolution optical microscopy techniques. Using fluorescence lifetime correlation spectroscopy (FLCS, an extension of fluorescence correlation spectroscopy, FCS) on a super-resolution stimulated emission depletion (STED) microscope, we here extend previous observations of nanoscale lipid dynamics in the plasma membrane of living mammalian cells. STED-FLCS allows an improved determination of spatiotemporal heterogeneity in molecular diffusion and interaction dynamics via a novel gated detection scheme, as demonstrated by a comparison between STED-FLCS and previous conventional STED-FCS recordings on fluorescent phosphoglycerolipid and sphingolipid analogues in the plasma membrane of live mammalian cells. The STED-FLCS data indicate that biophysical and biochemical parameters such as the affinity for molecular complexes strongly change over space and time within a few seconds. Drug treatment for cholesterol depletion or actin cytoskeleton depolymerization not only results in the already previously observed decreased affinity for molecular interactions but also in a slight reduction of the spatiotemporal heterogeneity. STED-FLCS specifically demonstrates a significant improvement over previous gated STED-FCS experiments and with its improved spatial and temporal resolution is a novel tool for investigating how heterogeneities of the cellular plasma membrane may regulate biofunctionality. PMID:26235350

  20. Study of DNA interactions with bifenthrin by spectroscopic techniques and molecular modeling

    NASA Astrophysics Data System (ADS)

    Zhu, Pan; Zhang, Guowen; Ma, Yadi; Zhang, Yepeng; Miao, Hong; Wu, Yongning

    2013-08-01

    The interaction between bifenthrin (BF) and calf thymus DNA (ctDNA) in physiological buffer (pH 7.4) was investigated by UV-vis absorption, fluorescence, circular dichroism (CD), and Fourier transform infrared (FT-IR) spectroscopy, coupled with viscosity measurements and molecular docking techniques. It was found that BF molecular could intercalate into the base pairs of ctDNA as evidenced by significant increases in absorption intensity, fluorescence polarization and relative viscosity of ctDNA, decrease in iodide quenching effect, and induced CD spectral changes. The association constant of BF with ctDNA was evaluated to be in the order of 104 L mol-1. Thermodynamic analysis of the binding data obtained at different temperatures suggested that the binding process was primarily driven by hydrogen bonds and van der Waals forces, as the values of the enthalpy change (?H) and the entropy change (?S) were calculated to be -31.13 ± 1.89 kJ mol-1 and -22.79 ± 1.21 J mol-1 K-1, respectively. The results of FT-IR spectra and molecular docking showed that a specific binding mainly existed between BF and adenine and guanine bases.

  1. The Synergy Between Total Scattering and Advanced Simulation Techniques: Quantifying Geopolymer Gel Evolution

    SciTech Connect

    White, Claire; Bloomer, Breaunnah E.; Provis, John L.; Henson, Neil J.; Page, Katharine L.

    2012-05-16

    With the ever increasing demands for technologically advanced structural materials, together with emerging environmental consciousness due to climate change, geopolymer cement is fast becoming a viable alternative to traditional cements due to proven mechanical engineering characteristics and the reduction in CO2 emitted (approximately 80% less CO2 emitted compared to ordinary Portland cement). Nevertheless, much remains unknown regarding the kinetics of the molecular changes responsible for nanostructural evolution during the geopolymerization process. Here, in-situ total scattering measurements in the form of X-ray pair distribution function (PDF) analysis are used to quantify the extent of reaction of metakaolin/slag alkali-activated geopolymer binders, including the effects of various activators (alkali hydroxide/silicate) on the kinetics of the geopolymerization reaction. Restricting quantification of the kinetics to the initial ten hours of reaction does not enable elucidation of the true extent of the reaction, but using X-ray PDF data obtained after 128 days of reaction enables more accurate determination of the initial extent of reaction. The synergies between the in-situ X-ray PDF data and simulations conducted by multiscale density functional theory-based coarse-grained Monte Carlo analysis are outlined, particularly with regard to the potential for the X-ray data to provide a time scale for kinetic analysis of the extent of reaction obtained from the multiscale simulation methodology.

  2. Experimental investigations on micro-scale thermal fluid phenomena by using advance flow diagnostic techniques

    NASA Astrophysics Data System (ADS)

    Jin, Zheyan

    2008-10-01

    Two-fluid mixing is an essential process for many microfluidic or "lab-on-a-chip" devices. Effective mixing of two fluids inside microchannels could be very challenging since turbulence is usually absent due to the nature of low Reynolds numbers of microflows. In the present study, a parametric study is carried out to elucidate underlying physics and to quantify the effectiveness of manipulating Electro-Kinetic-Instabilities (EKI) to actively control/enhance fluid mixing inside Y-shaped microchannels. Epi-fluorescence imaging technique is used to conduct qualitative flow visualization and quantitative scalar concentration field measurements to quantify the fluid mixing process inside the Y-shaped microchannels in terms of scalar concentration distributions, shedding frequency of the EKI waves and scalar mixing efficiency. The effects of the relevant parameters, such as the conductivity ratio of the two mixing streams, the strength of the applied static electric fields, the frequency and amplitude of the applied alternating perturbations, and micro-structures inside the microchannels on the evolution of the EKI waves and resultant fluid mixing process are investigated systematically. Micro-flows and heat transfer process inside small surface droplets have many interesting applications associated with microfluidics such as DNA molecule imaging, micro-pumps, and ink-jet printing. The second component of present study is to investigate the unsteady flow and heat transfer phenomena inside small surface droplets over a solid substrate at different temperature levels. Particle Image Velocimetry (PIV) technique is used to quantify the dynamics of the evaporation process and surface-tension induced Marangoni flows inside the small surface droplets. Molecular Tagging Thermometry (MTT) technique is used to map the transient temperature distributions inside the droplets to quantify the unsteady heat transfer process. The effects of the substrate temperature on the evaporation process, surface-tension induced Marangoni flows and micros-scale heat transfer process inside the surface droplets are quantified in detail.

  3. Advances in Resistive Pulse Sensors: Devices bridging the void between molecular and microscopic detection

    PubMed Central

    Kozak, Darby; Anderson, Will; Vogel, Robert; Trau, Matt

    2011-01-01

    Since the first reported use of a biological ion channel to detect differences in single stranded genomic base pairs in 1996, a renaissance in nanoscale resistive pulse sensors has ensued. This resurgence of a technique originally outlined and commercialized over fifty years ago has largely been driven by advances in nanoscaled fabrication, and ultimately, the prospect of a rapid and inexpensive means for genomic sequencing as well as other macromolecular characterization. In this pursuit, the potential application of these devices to characterize additional properties such as the size, shape, charge, and concentration of nanoscaled materials (10 – 900 nm) has been largely overlooked. Advances in nanotechnology and biotechnology are driving the need for simple yet sensitive individual object readout devices such as resistive pulse sensors. This review will examine the recent progress in pore-based sensing in the nanoscale range. A detailed analysis of three new types of pore sensors – in-series, parallel, and size-tunable pores – has been included. These pores offer improved measurement sensitivity over a wider particle size range. The fundamental physical chemistry of these techniques, which is still evolving, will be reviewed. PMID:22034585

  4. Genetics of hypertrophic cardiomyopathy: advances and pitfalls in molecular diagnosis and therapy

    PubMed Central

    Roma-Rodrigues, Catarina; Fernandes, Alexandra R

    2014-01-01

    Hypertrophic cardiomyopathy (HCM) is a primary disease of the cardiac muscle that occurs mainly due to mutations (>1,400 variants) in genes encoding for the cardiac sarcomere. HCM, the most common familial form of cardiomyopathy, affecting one in every 500 people in the general population, is typically inherited in an autosomal dominant pattern, and presents variable expressivity and age-related penetrance. Due to the morphological and pathological heterogeneity of the disease, the appearance and progression of symptoms is not straightforward. Most HCM patients are asymptomatic, but up to 25% develop significant symptoms, including chest pain and sudden cardiac death. Sudden cardiac death is a dramatic event, since it occurs without warning and mainly in younger people, including trained athletes. Molecular diagnosis of HCM is of the outmost importance, since it may allow detection of subjects carrying mutations on HCM-associated genes before development of clinical symptoms of HCM. However, due to the genetic heterogeneity of HCM, molecular diagnosis is difficult. Currently, there are mainly four techniques used for molecular diagnosis of HCM, including Sanger sequencing, high resolution melting, mutation detection using DNA arrays, and next-generation sequencing techniques. Application of these methods has proven successful for identification of mutations on HCM-related genes. This review summarizes the features of these technologies, highlighting their strengths and weaknesses. Furthermore, current therapeutics for HCM patients are correlated with clinically observed phenotypes and are based on the alleviation of symptoms. This is mainly due to insufficient knowledge on the mechanisms involved in the onset of HCM. Tissue engineering alongside regenerative medicine coupled with nanotherapeutics may allow fulfillment of those gaps, together with screening of novel therapeutic drugs and target delivery systems. PMID:25328416

  5. PREFACE: 15th International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT2013)

    NASA Astrophysics Data System (ADS)

    Wang, Jianxiong

    2014-06-01

    This volume of Journal of Physics: Conference Series is dedicated to scientific contributions presented at the 15th International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT 2013) which took place on 16-21 May 2013 at the Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China. The workshop series brings together computer science researchers and practitioners, and researchers from particle physics and related fields to explore and confront the boundaries of computing and of automatic data analysis and theoretical calculation techniques. This year's edition of the workshop brought together over 120 participants from all over the world. 18 invited speakers presented key topics on the universe in computer, Computing in Earth Sciences, multivariate data analysis, automated computation in Quantum Field Theory as well as computing and data analysis challenges in many fields. Over 70 other talks and posters presented state-of-the-art developments in the areas of the workshop's three tracks: Computing Technologies, Data Analysis Algorithms and Tools, and Computational Techniques in Theoretical Physics. The round table discussions on open-source, knowledge sharing and scientific collaboration stimulate us to think over the issue in the respective areas. ACAT 2013 was generously sponsored by the Chinese Academy of Sciences (CAS), National Natural Science Foundation of China (NFSC), Brookhaven National Laboratory in the USA (BNL), Peking University (PKU), Theoretical Physics Cernter for Science facilities of CAS (TPCSF-CAS) and Sugon. We would like to thank all the participants for their scientific contributions and for the en- thusiastic participation in all its activities of the workshop. Further information on ACAT 2013 can be found at http://acat2013.ihep.ac.cn. Professor Jianxiong Wang Institute of High Energy Physics Chinese Academy of Science Details of committees and sponsors are available in the PDF

  6. Advanced contrast nanoagents for photoacoustic molecular imaging, cytometry, blood test and photothermal theranostics†

    PubMed Central

    de la Zerda, Adam; Kim, Jin-Woo; Galanzha, Ekaterina I.; Gambhir, Sanjiv S.; Zharov, Vladimir P.

    2013-01-01

    Various nanoparticles have raised significant interest over the past decades for their unique physical and optical properties and biological utilities. Here we summarize the vast applications of advanced nanoparticles with a focus on carbon nanotube (CNT)-based or CNT-catalyzed contrast agents for photoacoustic (PA) imaging, cytometry and theranostics applications based on the photothermal (PT) effect. We briefly review the safety and potential toxicity of the PA/PT contrast nanoagents, while showing how the physical properties as well as multiple biological coatings change their toxicity profiles and contrasts. We provide general guidelines needed for the validation of a new molecular imaging agent in living subjects, and exemplify these guidelines with single-walled CNTs targeted to ?v?3, an integrin associated with tumor angiogenesis, and golden carbon nanotubes targeted to LYVE-1, endothelial lymphatic receptors. An extensive review of the potential applications of advanced contrast agents is provided, including imaging of static targets such as tumor angiogenesis receptors, in vivo cytometry of dynamic targets such as circulating tumor cells and nanoparticles in blood, lymph, bones and plants, methods to enhance the PA and PT effects with transient and stationary bubble conjugates, PT/PA Raman imaging and multispectral histology. Finally, theranostic applications are reviewed, including the nanophotothermolysis of individual tumor cells and bacteria with clustered nanoparticles, nanothrombolysis of blood clots, detection and purging metastasis in sentinel lymph nodes, spectral hole burning and multiplex therapy with ultrasharp rainbow nanoparticles. PMID:22025336

  7. Advances in the field of high?molecular?weight polycyclic aromatic hydrocarbon biodegradation by bacteria

    PubMed Central

    Kanaly, Robert A.; Harayama, Shigeaki

    2010-01-01

    Summary Interest in understanding prokaryotic biotransformation of high?molecular?weight polycyclic aromatic hydrocarbons (HMW PAHs) has continued to grow and the scientific literature shows that studies in this field are originating from research groups from many different locations throughout the world. In the last 10 years, research in regard to HMW PAH biodegradation by bacteria has been further advanced through the documentation of new isolates that represent diverse bacterial types that have been isolated from different environments and that possess different metabolic capabilities. This has occurred in addition to the continuation of in?depth comprehensive characterizations of previously isolated organisms, such as Mycobacterium vanbaalenii PYR?1. New metabolites derived from prokaryotic biodegradation of four? and five?ring PAHs have been characterized, our knowledge of the enzymes involved in these transformations has been advanced and HMW PAH biodegradation pathways have been further developed, expanded upon and refined. At the same time, investigation of prokaryotic consortia has furthered our understanding of the capabilities of microorganisms functioning as communities during HMW PAH biodegradation. PMID:21255317

  8. A Research Project-Based and Self-Determined Teaching System of Molecular Biology Techniques for Undergraduates

    ERIC Educational Resources Information Center

    Zhang, Shuping

    2008-01-01

    Molecular biology techniques play a very important role in understanding the biological activity. Students who major in biology should know not only how to perform experiments, but also the reasons for performing them. Having the concept of conducting research by integrating various techniques is especially important. This paper introduces a…

  9. Lip1 Lip2 Lip3 Naa Cr Cho PCho GPCho Identifying constituent tumor tissues subclasses in HR-MAS spectra using advanced blind source separation techniques

    E-print Network

    to histology. Conclusions Using advanced source separation techniques we can correctly decompose the observed tissues subclasses in HR-MAS spectra using advanced blind source separation techniques A. Croitor Sava, D vivo HR-MAS (high-resolution magic angle spinning spectroscopy) technique can preserve tissue

  10. Craniospinal Irradiation Techniques: A Dosimetric Comparison of Proton Beams With Standard and Advanced Photon Radiotherapy

    SciTech Connect

    Yoon, Myonggeun; Shin, Dong Ho; Kim, Jinsung; Kim, Jong Won; Kim, Dae Woong; Park, Sung Yong; Lee, Se Byeong; Kim, Joo Young; Park, Hyeon-Jin; Park, Byung Kiu; Shin, Sang Hoon

    2011-11-01

    Purpose: To evaluate the dosimetric benefits of advanced radiotherapy techniques for craniospinal irradiation in cancer in children. Methods and Materials: Craniospinal irradiation (CSI) using three-dimensional conformal radiotherapy (3D-CRT), tomotherapy (TOMO), and proton beam treatment (PBT) in the scattering mode was planned for each of 10 patients at our institution. Dosimetric benefits and organ-specific radiation-induced cancer risks were based on comparisons of dose-volume histograms (DVHs) and on the application of organ equivalent doses (OEDs), respectively. Results: When we analyzed the organ-at-risk volumes that received 30%, 60%, and 90% of the prescribed dose (PD), we found that PBT was superior to TOMO and 3D-CRT. On average, the doses delivered by PBT to the esophagus, stomach, liver, lung, pancreas, and kidney were 19.4 Gy, 0.6 Gy, 0.3 Gy, 2.5 Gy, 0.2 Gy, and 2.2 Gy for the PD of 36 Gy, respectively, which were significantly lower than the doses delivered by TOMO (22.9 Gy, 4.5 Gy, 6.1 Gy, 4.0 Gy, 13.3 Gy, and 4.9 Gy, respectively) and 3D-CRT (34.6 Gy, 3.6 Gy, 8.0 Gy, 4.6 Gy, 22.9 Gy, and 4.3 Gy, respectively). Although the average doses delivered by PBT to the chest and abdomen were significantly lower than those of 3D-CRT or TOMO, these differences were reduced in the head-and-neck region. OED calculations showed that the risk of secondary cancers in organs such as the stomach, lungs, thyroid, and pancreas was much higher when 3D-CRT or TOMO was used than when PBT was used. Conclusions: Compared with photon techniques, PBT showed improvements in most dosimetric parameters for CSI patients, with lower OEDs to organs at risk.

  11. Application of Energy Integration Techniques to the Design of Advanced Life Support Systems

    NASA Technical Reports Server (NTRS)

    Levri, Julie; Finn, Cory

    2000-01-01

    Exchanging heat between hot and cold streams within an advanced life support system can save energy. This savings will reduce the equivalent system mass (ESM) of the system. Different system configurations are examined under steady-state conditions for various percentages of food growth and waste treatment. The scenarios investigated represent possible design options for a Mars reference mission. Reference mission definitions are drawn from the ALSS Modeling and Analysis Reference Missions Document, which includes definitions for space station evolution, Mars landers, and a Mars base. For each scenario, streams requiring heating or cooling are identified and characterized by mass flow, supply and target temperatures and heat capacities. The Pinch Technique is applied to identify good matches for energy exchange between the hot and cold streams and to calculate the minimum external heating and cooling requirements for the system. For each pair of hot and cold streams that are matched, there will be a reduction in the amount of external heating and cooling required, and the original heating and cooling equipment will be replaced with a heat exchanger. The net cost savings can be either positive or negative for each stream pairing, and the priority for implementing each pairing can be ranked according to its potential cost savings. Using the Pinch technique, a complete system heat exchange network is developed and heat exchangers are sized to allow for calculation of ESM. The energy-integrated design typically has a lower total ESM than the original design with no energy integration. A comparison of ESM savings in each of the scenarios is made to direct future Pinch Analysis efforts.

  12. Nuclear structure of proton-rich intermediate mass nuclei studied with advanced lifetime measurement techniques

    NASA Astrophysics Data System (ADS)

    Morse, Christopher Scott

    The transition matrix elements between excited nuclear states provide valuable information about the structure of exotic nuclei. Lifetime measurements are a model-independent way to deduce these matrix elements from experimental data. Two studies of proton-rich nuclei near mass 70 are presented herein using advanced lifetime measurement techniques. The first study is a measurement of the 81+ and 91+ states in the odd-N, odd-Z nucleus 70As. The lifetimes of these states were determined by the application of the gamma-ray lineshape method to gamma-gamma coincidence data. The states were populated using with the 9Be(78Rb,70As) reaction and gamma rays were detected with the Segmented Germanium Array in coincidence with reaction products detected in the focal plane of the S800 Spectrograph. The B(E1;8+ ?7 -) and B(M1;9+?8 +) transition strengths were deduced and were found to support the assignment of these states to a coupling of the odd proton and neutron in the g9/2 orbital. The second study is a measurement of the 21+ state lifetime in the N=Z nucleus 74Rb. A novel technique called the Differential Recoil Distance Method was used to extract the lifetime from the gamma-ray spectra. The next-generation gamma-ray detector array GRETINA was used in the experiment, again coupled to the S800 Spectrograph to detect residues from 9Be(74Kr, 74Rb) charge exchange reactions. The B( E2;2+1?0+1) strength was calculated and is consistent with the measured strength of the transition between the isobaric analogue states in 74Kr, which may be a signature of shape coexistence in 74Rb.

  13. 75 FR 81643 - In the Matter of Certain Semiconductor Products Made by Advanced Lithography Techniques and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-28

    ...337-TA-729] In the Matter of Certain Semiconductor Products Made by Advanced Lithography...States after importation of certain semiconductor products made by advanced lithography...complaint named two respondents: Taiwan Semiconductor Manufacturing, Co., Ltd....

  14. Analysis of deformation patterns through advanced DINSAR techniques in Istanbul megacity

    NASA Astrophysics Data System (ADS)

    Balik Sanli, F.; Calò, F.; Abdikan, S.; Pepe, A.; Gorum, T.

    2014-09-01

    As result of the Turkey's economic growth and heavy migration processes from rural areas, Istanbul has experienced a high urbanization rate, with severe impacts on the environment in terms of natural resources pressure, land-cover changes and uncontrolled sprawl. As a consequence, the city became extremely vulnerable to natural and man-made hazards, inducing ground deformation phenomena that threaten buildings and infrastructures and often cause significant socio-economic losses. Therefore, the detection and monitoring of such deformation patterns is of primary importance for hazard and risk assessment as well as for the design and implementation of effective mitigation strategies. Aim of this work is to analyze the spatial distribution and temporal evolution of deformations affecting the Istanbul metropolitan area, by exploiting advanced Differential SAR Interferometry (DInSAR) techniques. In particular, we apply the Small BAseline Subset (SBAS) approach to a dataset of 43 TerraSAR-X images acquired, between November 2010 and June 2012, along descending orbits with an 11-day revisit time and a 3 m × 3 m spatial resolution. The SBAS processing allowed us to remotely detect and monitor subsidence patterns over all the urban area as well as to provide detailed information at the scale of the single building. Such SBAS measurements, effectively integrated with ground-based monitoring data and thematic maps, allows to explore the relationship between the detected deformation phenomena and urbanization, contributing to improve the urban planning and management.

  15. On Advanced Estimation Techniques for Exoplanet Detection and Characterization using Ground-based Coronagraphs

    NASA Technical Reports Server (NTRS)

    Lawson, Peter; Frazin, Richard

    2012-01-01

    The direct imaging of planets around nearby stars is exceedingly difficult. Only about 14 exoplanets have been imaged to date that have masses less than 13 times that of Jupiter. The next generation of planet-finding coronagraphs, including VLT-SPHERE, the Gemini Planet Imager, Palomar P1640, and Subaru HiCIAO have predicted contrast performance of roughly a thousand times less than would be needed to detect Earth-like planets. In this paper we review the state of the art in exoplanet imaging, most notably the method of Locally Optimized Combination of Images (LOCI), and we investigate the potential of improving the detectability of faint exoplanets through the use of advanced statistical methods based on the concepts of the ideal observer and the Hotelling observer. We propose a formal comparison of techniques using a blind data challenge with an evaluation of performance using the Receiver Operating Characteristic (ROC) and Localization ROC (LROC) curves. We place particular emphasis on the understanding and modeling of realistic sources of measurement noise in ground-based AO-corrected coronagraphs. The work reported in this paper is the result of interactions between the co-authors during a week-long workshop on exoplanet imaging that was held in Squaw Valley, California, in March of 2012

  16. Advances in Metal Artifact Reduction Techniques for Periprosthetic Soft Tissue Imaging.

    PubMed

    Ariyanayagam, Timothy; Malcolm, Paul Napier; Toms, Andoni Paul

    2015-09-01

    Artifact from metallic orthopedic prosthesis is caused by inhomogeneity in the B0 magnetic field, particularly in the frequency encoding direction. This results in signal voids, signal pileup, and geometric distortion. Advances in reducing this artifact allow us to assess the complications of joint replacement and improve imaging of nearby tissues such as within the pelvis. Selection of titanium implants and lower field strength MR units provide optimal conditions for artifact reduction. Conventional sequences can be optimized by using inversion recovery sequences, large matrices, high receiver bandwidths, and thin slices. Optimizing these parameters comes with a penalty in terms of signal-to-noise ratio or increased acquisition times. Successful artifact reduction depends on the strength of the frequency encoding gradients. Newer dedicated artifact reduction sequences include view-angle-tilting and a selection of multispectral techniques including multiacquisition variable-resonance image combination (MAVRIC) and slice encoding for metal artifact correction (SEMAC). Many of these are being used in combination. The multispectral sequences acquire three-dimensional data at very narrow frequencies and use of phase encoding for spatial localization. Planar images can then be reconstructed with very little susceptibility artifact. PMID:26583361

  17. Classification of human colonic tissues using FTIR spectra and advanced statistical techniques

    NASA Astrophysics Data System (ADS)

    Zwielly, A.; Argov, S.; Salman, A.; Bogomolny, E.; Mordechai, S.

    2010-04-01

    One of the major public health hazards is colon cancer. There is a great necessity to develop new methods for early detection of cancer. If colon cancer is detected and treated early, cure rate of more than 90% can be achieved. In this study we used FTIR microscopy (MSP), which has shown a good potential in the last 20 years in the fields of medical diagnostic and early detection of abnormal tissues. Large database of FTIR microscopic spectra was acquired from 230 human colonic biopsies. Five different subgroups were included in our database, normal and cancer tissues as well as three stages of benign colonic polyps, namely, mild, moderate and severe polyps which are precursors of carcinoma. In this study we applied advanced mathematical and statistical techniques including principal component analysis (PCA) and linear discriminant analysis (LDA), on human colonic FTIR spectra in order to differentiate among the mentioned subgroups' tissues. Good classification accuracy between normal, polyps and cancer groups was achieved with approximately 85% success rate. Our results showed that there is a great potential of developing FTIR-micro spectroscopy as a simple, reagent-free viable tool for early detection of colon cancer in particular the early stages of premalignancy among the benign colonic polyps.

  18. On Advanced Estimation Techniques for Exoplanet Detection and Characterization Using Ground-based Coronagraphs

    PubMed Central

    Lawson, Peter R.; Poyneer, Lisa; Barrett, Harrison; Frazin, Richard; Caucci, Luca; Devaney, Nicholas; Furenlid, Lars; G?adysz, Szymon; Guyon, Olivier; Krist, John; Maire, Jérôme; Marois, Christian; Mawet, Dimitri; Mouillet, David; Mugnier, Laurent; Pearson, Iain; Perrin, Marshall; Pueyo, Laurent; Savransky, Dmitry

    2015-01-01

    The direct imaging of planets around nearby stars is exceedingly difficult. Only about 14 exoplanets have been imaged to date that have masses less than 13 times that of Jupiter. The next generation of planet-finding coronagraphs, including VLT-SPHERE, the Gemini Planet Imager, Palomar P1640, and Subaru HiCIAO have predicted contrast performance of roughly a thousand times less than would be needed to detect Earth-like planets. In this paper we review the state of the art in exoplanet imaging, most notably the method of Locally Optimized Combination of Images (LOCI), and we investigate the potential of improving the detectability of faint exoplanets through the use of advanced statistical methods based on the concepts of the ideal observer and the Hotelling observer. We propose a formal comparison of techniques using a blind data challenge with an evaluation of performance using the Receiver Operating Characteristic (ROC) and Localization ROC (LROC) curves. We place particular emphasis on the understanding and modeling of realistic sources of measurement noise in ground-based AO-corrected coronagraphs. The work reported in this paper is the result of interactions between the co-authors during a week-long workshop on exoplanet imaging that was held in Squaw Valley, California, in March of 2012. PMID:26347393

  19. On Advanced Estimation Techniques for Exoplanet Detection and Characterization using Ground-Based Coronagraphs

    NASA Technical Reports Server (NTRS)

    Lawson, Peter R.; Frazin, Richard; Barrett, Harrison; Caucci, Luca; Devaney, Nicholas; Furenlid, Lars; Gladysz, Szymon; Guyon, Olivier; Krist, John; Maire, Jerome; Marois, Christian; Mawet, Dimitri; Mouillet, David; Mugnier, Laurent; Perrin, Marshall; Poyneer, Lisa; Pueyo, Laurent; Savransky, Dmitry; Soummer, Remi

    2012-01-01

    The direct imaging of planets around nearby stars is exceedingly difficult. Only about 14 exoplanets have been imaged to date that have masses less than 13 times that of Jupiter. The next generation of planet-finding coronagraphs, including VLT-SPHERE, the Gemini Planet Imager, Palomar P1640, and Subaru HiCIAO have predicted contrast performance of roughly a thousand times less than would be needed to detect Earth-like planets. In this paper we review the state of the art in exoplanet imaging, most notably the method of Locally Optimized Combination of Images (LOCI), and we investigate the potential of improving the detectability of faint exoplanets through the use of advanced statistical methods based on the concepts of the ideal observer and the Hotelling observer. We provide a formal comparison of techniques through a blind data challenge and evaluate performance using the Receiver Operating Characteristic (ROC) and Localization ROC (LROC) curves. We place particular emphasis on the understanding and modeling of realistic sources of measurement noise in ground-based AO-corrected coronagraphs. The work reported in this paper is the result of interactions between the co-authors during a week-long workshop on exoplanet imaging that was held in Squaw Valley, California, in March of 2012.

  20. Fluorescence imaging with near-infrared light: new technological advances that enable in vivo molecular imaging.

    PubMed

    Ntziachristos, Vasilis; Bremer, Christoph; Weissleder, Ralph

    2003-01-01

    A recent development in biomedical imaging is the non-invasive mapping of molecular events in intact tissues using fluorescence. Underpinning to this development is the discovery of bio-compatible, specific fluorescent probes and proteins and the development of highly sensitive imaging technologies for in vivo fluorescent detection. Of particular interest are fluorochromes that emit in the near infrared (NIR), a spectral window, whereas hemoglobin and water absorb minimally so as to allow photons to penetrate for several centimetres in tissue. In this review article we concentrate on optical imaging technologies used for non-invasive imaging of the distribution of such probes. We illuminate the advantages and limitations of simple photographic methods and turn our attention to fluorescence-mediated molecular tomography (FMT), a technique that can three-dimensionally image gene expression by resolving fluorescence activation in deep tissues. We describe theoretical specifics, and we provide insight into its in vivo capacity and the sensitivity achieved. Finally, we discuss its clinical feasibility. PMID:12541130

  1. Electrical characterization of ensemble of GaN nanowires grown by the molecular beam epitaxy technique

    SciTech Connect

    Kolkovsky, Vl.; Zytkiewicz, Z. R.; Sobanska, M.; Klosek, K.

    2013-08-26

    High quality Schottky contacts are formed on GaN nanowires (NWs) structures grown by the molecular beam epitaxy technique on Si(111) substrate. The current-voltage characteristics show the rectification ratio of about 10{sup 3} and the leakage current of about 10{sup ?4} A/cm{sup 2} at room temperature. From the capacitance-voltage measurements the free carrier concentration in GaN NWs is determined as about 10{sup 16} cm{sup ?3}. Two deep levels (H200 and E280) are found in the structures containing GaN NWs. H200 is attributed to an extended defect located at the interface between the substrate and SiN{sub x} or near the sidewalls at the bottom of the NWs whereas E280 is tentatively assigned to a gallium-vacancy- or nitrogen interstitials-related defect.

  2. Bacterial community structures of deep-sea water investigated by molecular biological techniques.

    PubMed

    Terahara, Takeshi; Yamada, Katsuhisa; Nakayama, Jiro; Igarashi, Yasuhiro; Kobayashi, Takeshi; Imada, Chiaki

    2016-02-01

    The aim of the present study was to investigate the bacterial community structures of deep-sea water (DSW) and surface seawater (SSW) samples in Japan by molecular biological techniques. DGGE analyses and pyrosequencing analysis revealed that bacterial community structures of DSW were diverse and differed from those of SSW. This is the first report on the horizontal variation of bacterial community structures of DSW throughout Japan. In addition, pyrosequencing analysis revealed that the number of phyla in DSW was larger than that in SSW, and specific phyla, such as Firmicutes and Planctomycetes, were characterized by a higher proportion of the bacterial community structure in DSW than in SSW. Taken together, these results indicate that a variety of bacteria that are specifically adapted to the DSW environments can be expected to be found in DSW, and DSW would thus be a potential resource for novel or unique microorganisms and compounds. PMID:26475936

  3. APPLICATION OF ADVANCED IN VITRO TECHNIQUES TO MEASURE, UNDERSTAND AND PREDICT THE KINETICS AND MECHANISMS OF XENOBIOTIC METABOLISM

    EPA Science Inventory

    We have developed a research program in metabolism that involves numerous collaborators across EPA as well as other federal and academic labs. A primary goal is to develop and apply advanced in vitro techniques to measure, understand and predict the kinetics and mechanisms of xen...

  4. Techniques Optimized for Reducing Instabilities in Advanced Nickel-Base Superalloys for Turbine Blades

    NASA Technical Reports Server (NTRS)

    MacKay, Rebecca A.; Locci, Ivan E.; Garg, anita; Ritzert, Frank J.

    2002-01-01

    The High-Speed Research (HSR) Airfoil Alloy program developed fourth-generation single-crystal superalloys with up to an 85 F increase in creep rupture capability over current production airfoil alloys. Recent results have been generated at the NASA Glenn Research Center on these fourth-generation alloys, but in coated form, for subsonic turbine blade applications under NASA's Ultra-Efficient Engine Technology (UEET) Program. One goal for UEET is to optimize the airfoil alloy/thermal barrier coating system for 3100 F turbine inlet temperatures. The state-of-the art turbine blade airfoil system consists of a superalloy single crystal that provides the basic mechanical performance of the airfoil. A thermal barrier coating is used to reduce the temperature of the base superalloy, and a bondcoat is deposited between the base material and the thermal barrier coating. The bondcoat improves the oxidation and corrosion resistance of the base superalloy and improves the spallation resistance of the thermal barrier coating. A commercial platinum aluminide bondcoat was applied to the HSR-developed alloys, and a diffusion zone developed as a result of interaction between the bondcoat and the superalloy. Optimized strength is obtained for superalloys when the refractory element content is high and the limits of microstructural stability are approached or exceeded slightly. For fourthgeneration alloys, instability leads to the formation of topologically close packed (TCP) phases, which form internally in the superalloy, and a secondary reaction zone (SRZ), which forms under the diffusion zone. There was a concern that excessive quantities of either TCP or SRZ might decrease the mechanical properties of the superalloy, with SRZ thought to be particularly detrimental and its formation unpredictable. Thus, an SRZreduction effort was initiated in the NASA UEET Program so that methods developed during the HSR project could be optimized further to reduce or eliminate the SRZ. An SRZ is a three-phase constituent composed of TCP and stringers of gamma phase in a matrix of gamma prime. An incoherent grain boundary separates the SRZ from the gammagamma prime microstructure of the superalloy. The SRZ is believed to form as a result of local chemistry changes in the superalloy due to the application of the diffusion aluminide bondcoat. Locally high surface stresses also appear to promote the formation of the SRZ. Thus, techniques that change the local alloy chemistry or reduce surface stresses have been examined for their effectiveness in reducing SRZ. These SRZ-reduction steps are performed on the test specimen or the turbine blade before the bondcoat is applied. Stressrelief heat treatments developed at NASA Glenn have been demonstrated to reduce significantly the amount of SRZ that develops during subsequent high-temperature exposures. Stress-relief heat treatments reduce surface stresses by recrystallizing a thin surface layer of the superalloy. However, in alloys with very high propensities to form SRZ, stress relief heat treatments alone do not eliminate SRZ entirely. Thus, techniques that modify the local chemistry under the bondcoat have been emphasized and optimized successfully at Glenn. One such technique is carburization, which changes the local chemistry by forming submicron carbides near the surface of the superalloy. Detailed characterizations have demonstrated that the depth and uniform distribution of these carbides are enhanced when a stress relief treatment and an appropriate surface preparation are employed in advance of the carburization treatment. Even in alloys that have the propensity to develop a continuous SRZ layer beneath the diffusion zone, the SRZ has been completely eliminated or reduced to low, manageable levels when this combination of techniques is utilized. Now that the techniques to mitigate SRZ have been established at Glenn, TCP phase formation is being emphasized in ongoing work under the UEET Program. The limitsf stability of the fourth-generation alloys with respect to TCP phase formation are currently bei

  5. Full symmetry implementation in condensed matter and molecular physics-Modified group projector technique

    NASA Astrophysics Data System (ADS)

    Damnjanovi?, Milan; Miloševi?, Ivanka

    2015-06-01

    Symmetry is well established as one of the fundamental concepts in physics, accurately extracting relevant characteristics of the studied object, giving deep and transparent insight to its properties. In the solid state and molecular physics the most abundant application is reduction of the dimension of the eigenproblem of the Hamiltonian, with the resulting eigenvectors labeled by good quantum numbers, forming the so called symmetry adapted basis. Such a basis is the starting point for subsequent analysis of the physical properties of the system, performed usually by applying adequate perturbation technique. Standard procedure for finding a symmetry adapted basis involves Wigner operators, which are sums of the operators acting in the quantum state space (Hilbert space, most usually) over all elements of the symmetry group of the systems. However, both the dimension of the state space and the number of the symmetry transformations are infinite even in the simplest approximate models in crystal physics making obstacles for direct application of the standard Wigner projector technique, and its numerical implementation. On the other hand, there is a minimal part of the system, the full symmetry elementary cell (symcell), from which the whole system can be built by action of the full symmetry group elements on it. A clear heuristic idea, that symcell and full symmetry group, determine the properties of the entire system, is fully realized within modified group projector technique. Namely, when applying this technique, the full symmetry of the system is used to provide reduction of calculations to the symcell only, singling out its state space (of a finite dimension!) as the effective state space to be worked in. Physical observables, expressed through their irreducible tensor components, obtain their counterparts in this finite-dimensional space of a symcell. It remains to consider only the symmetry transformations which leave the symcell invariant. This is absolutely sufficient for the complete information on the properties of the system. In this report we review the modified group projector technique, giving detailed algorithm for its application, which is also a clear prescription for its numerical implementation. Generality of the method allows unified treatment of the most important dynamical models for ions (lattice dynamics within harmonic approximation), electrons (tight-binding method for the quantum states) and spin subsystem (spin waves in quasi classical approach), with specific details considered separately. Finally, relaxation techniques, optimization of the structure and of the spin ordering are analyzed, in order to provide the most efficient symmetry based procedures.

  6. New AFM Techniques for Investigating Molecular Growth Mechanisms of Protein Crystals

    NASA Technical Reports Server (NTRS)

    Li, Huayu; Nadarajah, Arunan; Konnert, John H.; Pusey, Marc L.

    1998-01-01

    Atomic Force Microscopy (AFM) has emerged as a powerful technique for investigating protein crystal growth. Earlier AFM studies were among the first to demonstrate that these crystals grew by dislocation and 2D nucleation growth mechanisms [1]. These investigations were restricted to the micron range where only surface features, such as dislocation hillocks and 2D islands are visible. Most AFM instruments can scan at higher resolutions and have the potential to resolve individual protein molecules at nanometer ranges. Such scans are essential for determining the molecular packing arrangements on crystal faces and for probing the growth process at the molecular level. However, at this resolution the AFM tip influences the image produced, with the resulting image being a convolution of the tip shape and the surface morphology [2]. In most studies this problem is resolved by deconvoluting the image to obtain the true surface morphology. Although deconvolution routines work reasonably well for simple one- dimensional shapes, for complex surfaces this approach does not produce accurate results. In this study we devised a new approach which takes advantage of the precise molecular order of crystal surfaces, combined with the knowledge of individual molecular shapes from the crystallographic data of the protein and the AFM tip shape. This information is used to construct expected theoretical AFM images by convoluting the tip shape with the constructed crystal surface shape for a given surface packing arrangement. By comparing the images from actual AFM scans with the constructed ones for different possible surface packing arrangements, the correct packing arrangement can be conclusively determined. This approach was used in this study to determine the correct one from two possible packing arrangements on (I 10) faces of tetragonal lysozyme crystals. Another novel AFM technique was also devised to measure the dimension of individual growth units of the crystal faces. Measuring these units was not attempted before and most studies have assumed that the growth unit consisted of individual protein molecules. The linescan mode of AFM instruments allows the crystal surface to be scanned along a single line. By scanning across a growth step an image showing the motion of the step is obtained. Normally such an image shows a straight line for continuous and constant step velocity. In this study by increasing the scan rate and by decreasing the step velocity (by decreasing the supersaturation), we were able to capture images of individual growth events, shown by jump discontinuities in the step line. By suitable integration of the image the growth unit dimension in the scanned direction can be obtained. Since multiple units can be involved in the growth process it is necessary to collect a statistically relevant sample before drawing conclusions about the growth mechanism. This technique was successfully employed to obtain the dimensions of growth units for the (110) face, showing that they consisted of various aggregates corresponding to the 43 helices in the crystal structure.

  7. Development of Ultra-High Molecular Weight Polyethylene (UHMWPE) Coating by Cold Spray Technique

    NASA Astrophysics Data System (ADS)

    Ravi, Kesavan; Ichikawa, Yuji; Deplancke, Tiana; Ogawa, Kazuhiro; Lame, Olivier; Cavaille, Jean-Yves

    2015-08-01

    Ultra-high molecular weight polyethylene or UHMWPE is an extremely difficult material to coat with, as it is rubbery and chemically very inert. The Cold Spray process appears to be a promising alternative processing technique but polymers are in general difficult to deposit using this method. So, attempts to develop UHMWPE coatings were made using a downstream injection cold spray technique incorporating a few modifications. A conventional cold spray machine yielded only a few deposited particles of UHMWPE on the substrate surface, but with some modifications in the nozzle geometry (especially the length and inner geometry) a thin coating of 45 ?m on Al substrate was obtained. Moreover, experiments with the addition of fumed nano-alumina to the feedstock yielded a coating of 1-4 mm thickness on Al and polypropylene substrates. UHMWPE was seen to be melt crystallized during the coating formation, as can be seen from the differential calorimetry curves. Influence of nano-ceramic particles was explained by observing the creation of a bridge bond between UHMWPE particles.

  8. Low-mass molecular dynamics simulation: a simple and generic technique to enhance configurational sampling.

    PubMed

    Pang, Yuan-Ping

    2014-09-26

    CLN025 is one of the smallest fast-folding proteins. Until now it has not been reported that CLN025 can autonomously fold to its native conformation in a classical, all-atom, and isothermal-isobaric molecular dynamics (MD) simulation. This article reports the autonomous and repeated folding of CLN025 from a fully extended backbone conformation to its native conformation in explicit solvent in multiple 500-ns MD simulations at 277K and 1atm with the first folding event occurring as early as 66.1ns. These simulations were accomplished by using AMBER forcefield derivatives with atomic masses reduced by 10-fold on Apple Mac Pros. By contrast, no folding event was observed when the simulations were repeated using the original AMBER forcefields of FF12SB and FF14SB. The results demonstrate that low-mass MD simulation is a simple and generic technique to enhance configurational sampling. This technique may propel autonomous folding of a wide range of miniature proteins in classical, all-atom, and isothermal-isobaric MD simulations performed on commodity computers-an important step forward in quantitative biology. PMID:25181342

  9. AB140. Ten years experiences of diagnosis spinal muscular atrophy using molecular techniques

    PubMed Central

    Nguyen, Thi Phuong Mai; Nguyen, Thi Mai Huong; Ngo, Manh Tien; Ly, Thi Thanh Ha; Ngo, Thi Tuyet Nhung; An, Thuy Lan; Vu, Dinh Quang; Nguyen, Xuan Huy; Ngo, Diem Ngoc; Bui, Phuong Thao; Nguyen, Ngoc Khanh; Vu, Chi Dung; Tran, Danh Cuong

    2015-01-01

    Background and objective Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder caused by mutations in the survival motor neuron gene (SMN). This article aims to identify the deletion exon 7 of SMN1/SMN2 genes in postnatal diagnosis and prenatal diagnosis with spinal muscular atrophy. Methods A total of 1,111 patients suspected SMA and 66 pregnant women who had affected children were collected from 2005 to 2015. The deletion of exon 7 SMN1/SMN2 genes was identified by PCR-restriction fragment length polymorphism (RFLP) techniques. Results We identified a homozygous deletion exon 7 of SMN1 in 353/1,111 (31.77%); 55/1,111 (4.95%) patients had deletion exon 7 of SMN-2 gene. In 66 pregnant women, there is 14/67 (20.9%) fetuses had deletion exon 7 of SMN-1 gene; 2/67 (2.98%) fetuses had deletion exon 7 of SMN-2 gene and 51/67 (76.12%) fetuses had no deletion. Conclusions Using molecular techniques to detect the deletion exon 7 of SMN1 gene is useful for postnatal and prenatal diagnosis with SMA.

  10. Advanced Glycation End Products: A Molecular Target for Vascular Complications in Diabetes

    PubMed Central

    Yamagishi, Sho-ichi; Nakamura, Nobutaka; Suematsu, Mika; Kaseda, Kuniyoshi; Matsui, Takanori

    2015-01-01

    A nonenzymatic reaction between reducing sugars and amino groups of proteins, lipids and nucleic acids contributes to the aging of macromolecules and subsequently alters their structural integrity and function. This process has been known to progress at an accelerated rate under hyperglycemic and/or oxidative stress conditions. Over a course of days to weeks, early glycation products undergo further reactions such as rearrangements and dehydration to become irreversibly cross-linked, fluorescent and senescent macroprotein derivatives termed advanced glycation end products (AGEs). There is a growing body of evidence indicating that interaction of AGEs with their receptor (RAGE) elicits oxidative stress generation and as a result evokes proliferative, inflammatory, thrombotic and fibrotic reactions in a variety of cells. This evidence supports AGEs’ involvement in diabetes- and aging-associated disorders such as diabetic vascular complications, cancer, Alzheimer’s disease and osteoporosis. Therefore, inhibition of AGE formation could be a novel molecular target for organ protection in diabetes. This report summarizes the pathophysiological role of AGEs in vascular complications in diabetes and discusses the potential clinical utility of measurement of serum levels of AGEs for evaluating organ damage in diabetes. PMID:26605646

  11. Inherited pancreatic endocrine tumor syndromes: advances in molecular pathogenesis, diagnosis, management, and controversies.

    PubMed

    Jensen, Robert T; Berna, Marc J; Bingham, David B; Norton, Jeffrey A

    2008-10-01

    Pancreatic endocrine tumors (PETs) can occur as part of 4 inherited disorders, including Multiple Endocrine Neoplasia type 1 (MEN1), von Hippel-Lindau disease (VHL), neurofibromatosis 1 (NF-1) (von Recklinghausen disease), and the tuberous sclerosis complex (TSC). The relative frequency with which patients who have these disorders develop PETs is MEN1>VHL>NF-1>TSC. Over the last few years, there have been major advances in the understanding of the genetics and molecular pathogenesis of these disorders as well in the localization and the medical and surgical treatment of PETs in such patients. The study of PETs in these disorders not only has provided insights into the possible pathogenesis of sporadic PETs but also has presented several unique management and treatment issues, some of which are applicable to patients with sporadic PETs. Therefore, the study of PETs in these uncommon disorders has provided valuable insights that, in many cases, are applicable to the general group of patients with sporadic PETs. In this article, these areas are reviewed briefly along with the current state of knowledge of the PETs in these disorders, and the controversies that exist in their management are summarized briefly and discussed. PMID:18798544

  12. Molecular Advances Leading to Treatment Implications for Fragile X Premutation Carriers

    PubMed Central

    Polussa, Jonathan; Schneider, Andrea; Hagerman, Randi

    2014-01-01

    Fragile X syndrome (FXS) is the most common single gene cause of intellectual disability and it is characterized by a CGG expansion of more than 200 repeats in the FMR1 gene, leading to methylation of the promoter and gene silencing. The fragile X premutation, characterized by a 55 to 200 CGG repeat expansion, causes health problems and developmental difficulties in some, but not all, carriers. The premutation causes primary ovarian insufficiency in approximately 20% of females, psychiatric problems (including depression and/or anxiety) in approximately 50% of carriers and a neurodegenerative disorder, the fragile X-associated tremor ataxia syndrome (FXTAS), in approximately 40% of males and 16% of females later in life. Recent clinical studies in premutation carriers have expanded the health problems that may be seen. Advances in the molecular pathogenesis of the premutation have shown significant mitochondrial dysfunction and oxidative stress in neurons which may be amenable to treatment. Here we review the clinical problems of carriers and treatment recommendations. PMID:25436181

  13. Removal of effluent dissolved organic matter of different molecular sizes by advanced treatments and soil infiltration.

    PubMed

    Zhang, Xue; Zhao, Xuan; Gao, Yutuan; Zhang, Meng

    2014-01-01

    Removal of municipal effluent-derived dissolved organic matter (DOM) of various apparent molecular weights (AMWs) was compared among ozonation, nanofiltration, ultrafiltration, and magnetic ion exchange (MIEX) resin coagulation. These advanced technologies were applied as pretreatments for soil aquifer treatment (SAT). Soil aquifer treatment alone removed 20 to 30% of dissolved organic carbon (DOC) and UV254. Soil aquifer treatment effectively removed 100% and 76% of DOM with AMWs of 21.3 to 31.6 kDa and 0.4 to 1.0 kDa, respectively. With pretreatments of ozonation, MIEX resin coagulation and nanofiltration, substantially higher removals (40 to 75%) were achieved for DOC and UV254. The removal efficiency of the entire system decreased as nanofiltration-SAT > ozonation-SAT > MIEX-SAT > ultrafiltration-SAT, which is positively related to the removal efficiency for medium AMW (1.8 to 7.7 kDa, mainly humic substances) DOM during pretreatments. Different pretreatments should, therefore, be chosen in accordance with the water quality of feed water and water products and SAT removal efficiency. PMID:24617114

  14. Advanced Glycation End Products: A Molecular Target for Vascular Complications in Diabetes.

    PubMed

    Yamagishi, Sho-Ichi; Nakamura, Nobutaka; Suematsu, Mika; Kaseda, Kuniyoshi; Matsui, Takanori

    2015-01-01

    A nonenzymatic reaction between reducing sugars and amino groups of proteins, lipids and nucleic acids contributes to the aging of macromolecules and subsequently alters their structural integrity and function. This process has been known to progress at an accelerated rate under hyperglycemic and/or oxidative stress conditions. Over a course of days to weeks, early glycation products undergo further reactions such as rearrangements and dehydration to become irreversibly cross-linked, fluorescent and senescent macroprotein derivatives termed advanced glycation end products (AGEs). There is a growing body of evidence indicating that interaction of AGEs with their receptor (RAGE) elicits oxidative stress generation and as a result evokes proliferative, inflammatory, thrombotic and fibrotic reactions in a variety of cells. This evidence supports AGEs' involvement in diabetes- and aging-associated disorders such as diabetic vascular complications, cancer, Alzheimer's disease and osteoporosis. Therefore, inhibition of AGE formation could be a novel molecular target for organ protection in diabetes. This report summarizes the pathophysiological role of AGEs in vascular complications in diabetes and discusses the potential clinical utility of measurement of serum levels of AGEs for evaluating organ damage in diabetes. PMID:26605646

  15. Utilizing advanced polymerization techniques for simplifying polymer grafting from silica colloidal crystal substrates

    NASA Astrophysics Data System (ADS)

    Yerneni, Charu K.

    Polyacrylamide has been well established as a biocompatible material when Polyacrylamide gel electrophoresis (PAGE) came into existence in the 1960s. Under aqueous buffer conditions it becomes non-adsorptive to proteins and due to its molecular level pore forming nature could be used in size based biomolecule separations. Since then considerable research has been done to explore the non-adsorptive nature of polyacrylamide on a platform or substrate. Attempts were made to grow polyacrylamide chains from silica as a substrate which can then be used in various protein separation techniques. Based on an ionic polymerization method which was used for gel casting in PAGE, polymers were grown on silica gel. Though considerable thickness could be achieved, polymerization was not just confined to the surface. Therefore a rigid polymer brush layer could not be achieved. Atom transfer radical polymerization (ATRP) method showed the solution to this problem. Polymer brush layers with acceptable thickness could now be achieved for growing polyacrylamide from silica gel. Yet it still suffered from several disadvantages such as the need of an inert atmosphere for polymerization and limited thickness. Many developments have taken place in the past decade which led to improvements in substrate and polymerization methods. This research used non porous sub-micron silica as the substrate and AGET ATRP (Activator generated electron transfer atom transfer radical polymerization) for surface grafting polyacrylamide. Non porous submicron silica has been shown to be a better stationary phase substrate for protein separations than conventional substrates. AGET ATRP enables polymerization to be performed under ambient conditions and in water based solutions which gives thicknesses much higher than conventional ATRP. Data from various analytical techniques showed that within the experimental range the polymerization is linear and has decent control. This means silica nanoparticles coated with polyacrylamide of varying thickness can be produced by varying the reaction time. Linear polymerization kinetics was studied using IR spectroscopy, elemental analysis, ellipsometry, GPC etc. All of them closely agree with each other. Attempts were made to expand the applicability of this novel way of material synthesis. HILIC is known as a premium separation mode for polar analytes. Glycoproteins form an important class of analytes which need better separation columns. Polyacrylamide coated nonporous colloidal silica is shown here to be a better column packing material. Combined results show that AGET ATRP can be a better and simpler alternative to ATRP for grafting polyacrylamide onto silica based substrates. Future efforts can possibly lead to the expansion of the applicability of this method for making materials for many other separation methods.

  16. [The use of molecular cytogenetic and cytogenetic techniques for the diagnosis of Prader-Willi and Angelman syndrome].

    PubMed

    Iourov, I Y; Vorsanova, S G; Kurinnaaya, O S; Kolotii, A D; Demidova, I A; Kravets, V S; Yurov, Yu B

    2014-01-01

    We examined 30 patients with a presumptive diagnosis of Prader-Willi and Angelman syndromes. In four patients, 15q11.2-q13 deletions were identified by cytogenetic techniques. The FISH method was used to study eight patients, in five of them microdeletions were also confirmed. High-resolution comparative genomic hybridization (CGH) and comparative genomic hybridization using DNA microarrays (array CGH) allowed to find 15q11.2-q13 deletions in five patients. These cases demonstrate the need for high-resolution post-genomic technologies (array CGH - molecular karyotyping) in the combination with classical cytogenetic and molecular cytogenetic techniques. PMID:24637817

  17. Molecular Imaging of Tumors Using a Quantitative T1 Mapping Technique via Magnetic Resonance Imaging

    PubMed Central

    Herrmann, Kelsey; Johansen, Mette L.; Craig, Sonya E.; Vincent, Jason; Howell, Michael; Gao, Ying; Lu, Lan; Erokwu, Bernadette; Agnes, Richard S.; Lu, Zheng-Rong; Pokorski, Jonathan K.; Basilion, James; Gulani, Vikas; Griswold, Mark; Flask, Chris; Brady-Kalnay, Susann M.

    2015-01-01

    Magnetic resonance imaging (MRI) of glioblastoma multiforme (GBM) with molecular imaging agents would allow for the specific localization of brain tumors. Prior studies using T1-weighted MR imaging demonstrated that the SBK2-Tris-(Gd-DOTA)3 molecular imaging agent labeled heterotopic xenograft models of brain tumors more intensely than non-specific contrast agents using conventional T1-weighted imaging techniques. In this study, we used a dynamic quantitative T1 mapping strategy to more objectively compare intra-tumoral retention of the SBK2-Tris-(Gd-DOTA)3 agent over time in comparison to non-targeted control agents. Our results demonstrate that the targeted SBK2-Tris-(Gd-DOTA)3 agent, a scrambled-Tris-(Gd-DOTA)3 control agent, and the non-specific clinical contrast agent Optimark™ all enhanced flank tumors of human glioma cells with similar maximal changes on T1 mapping. However, the retention of the agents differs. The non-specific agents show significant recovery within 20 min by an increase in T1 while the specific agent SBK2-Tris-(Gd-DOTA)3 is retained in the tumors and shows little recovery over 60 min. The retention effect is demonstrated by percent change in T1 values and slope calculations as well as by calculations of gadolinium concentration in tumor compared to muscle. Quantitative T1 mapping demonstrates the superior binding and retention in tumors of the SBK2-Tris-(Gd-DOTA)3 agent over time compared to the non-specific contrast agent currently in clinical use. PMID:26435847

  18. A Structure-Activity Relationship Study of Naphthoquinone Derivatives as Antitubercular Agents Using Molecular Modeling Techniques.

    PubMed

    Sharma, Mukesh C

    2015-12-01

    Tuberculosis (TB) is one of the major causes of death worldwide. Mycobacterium tuberculosis, the leading causative agent of TB, is responsible for the morbidity and mortality of a large population worldwide. In view of above and as a part of our effort to develop new and potent anti-TB agents, a series of substituted naphthoquinone derivatives were subjected to molecular modeling using various feature selection methods. The statistically significant best 2D-QSAR model having correlation coefficient [Formula: see text] and cross-validated squared correlation coefficient [Formula: see text] with external predictive ability of [Formula: see text] was developed by SA-PLS, and group-based QSAR model having [Formula: see text] and [Formula: see text] with [Formula: see text] was developed by SA-PLS. Further analysis using three-dimensional QSAR technique identifies a suitable model obtained by SA-partial least square method leading to antitubercular activity prediction. k-nearest neighbor molecular field analysis was used to construct the best 3D-QSAR model using SA-PLS method, showing good correlative and predictive capabilities in terms of [Formula: see text] and [Formula: see text]. The pharmacophore analysis results obtained from this study show that the distance between the aromatic/hydrophobic and the naphthoquinone moiety sites to the aliphatic and acceptor groups should be connected with almost the same distance for significant antitubercular activity. The information rendered by QSAR models may lead to a better understanding of structural requirements of antitubercular activity and also can help in the design of novel potent antitubercular activity. PMID:26159131

  19. The Role of Molecular Scale Investigations in Advanci,ng the Frontiers of Contaminant Speciation and Bioavailability in Soils

    E-print Network

    Sparks, Donald L.

    Speciation and Bioavailability in Soils Donald L. Sparks* Department of Plant and Soil Sciences, University and heterogeneous soils and poultry litter will be addressed. For example, using a variety of molecular attenuation mechanism, significantly affecting the bioavailability of metals. In recent years, micro-focused X

  20. Advanced Sensing and Control Techniques to Facilitate Semi-Autonomous Decommissioning

    SciTech Connect

    Schalkoff, Robert J.

    1999-06-01

    This research is intended to advance the technology of semi-autonomous teleoperated robotics as applied to Decontamination and Decommissioning (D&D) tasks. Specifically, research leading to a prototype dual-manipulator mobile work cell is underway. This cell is supported and enhanced by computer vision, virtual reality and advanced robotics technology.

  1. An advanced technique for speciation of organic nitrogen in atmospheric aerosols

    NASA Astrophysics Data System (ADS)

    Samy, S.; Robinson, J.; Hays, M. D.

    2011-12-01

    The chemical composition of organic nitrogen (ON) in the environment is a research topic of broad significance. The topic intersects the branches of atmospheric, aquatic, and ecological science; thus, a variety of instrumentation, analytical methods, and data interpretation tools have evolved for determination of ON. Recent studies that focus on atmospheric particulate nitrogen (N) suggest a significant fraction (20-80%) of total N is bound in organic compounds. The sources, bioavailability and transport mechanisms of these N-containing compounds can differ, producing a variety of environmental consequences. Amino acids (AA) are a key class of atmospheric ON compounds that can contribute to secondary organic aerosol (SOA) formation and potentially influence water cycles, air pollutant scavenging, and the radiation balance. AA are water-soluble organic compounds (WSOC) that can significantly alter the acid-base chemistry of aerosols, and may explain the buffering capacity that impacts heterogeneous atmospheric chemistry. The chemical transformations that N-containing organic compounds (including AA) undergo can increase the light-absorbing capacity of atmospheric carbon via formation of 'brown carbon'. Suggested sources of atmospheric AA include: marine surface layer transport from bursting sea bubbles, the suspension of bacteria, fungi, algae, pollen, spores, or biomass burning. Methodology for detection of native (underivatized) amino acids (AA) in atmospheric aerosols has been developed and validated (Samy et al., 2011). This presentation describes the use of LC-MS (Q-TOF) and microwave-assisted gas phase hydrolysis for detection of free and combined amino acids in aerosols collected in a Southeastern U.S. forest environment. Accurate mass detection and the addition of isotopically labeled surrogates prior to sample preparation allows for sensitive quantitation of target AA in a complex aerosol matrix. A total of 16 native AA were detected above the reporting threshold as water-soluble free AA, with an average concentration of 22 ± 9 ng m-3 (N=13). Following microwave-assisted gas phase hydrolysis, the total AA concentration in the forest environment increased significantly (70 ± 35 ng m-3) and additional compounds (methionine, isoleucine) were detected above the reporting threshold. The ability to quantify AA in aerosol samples without derivatization reduces time consuming preparation procedures while providing the advancement of selective mass determination that eliminates potential interferences associated with traditional fluorescence detection. This step forward in precise mass determination with the use of internal standardization, improves the confidence of compound identification. With the increasing focus on WSOC (including ON) characterization in the atmospheric science community, native detection by LC-MS (Q-TOF) will play a central role in determining the most direct approach to quantify an increasing fraction of the co-extracted polar organic compounds. Method application for further characterization of atmospheric ON will be discussed. Reference: Samy, S., Robinson, J., and M.D. Hays. "An Advanced LC-MS (Q-TOF) Technique for the Detection of Amino Acids in Atmospheric Aerosols", Analytical Bioanalytical Chemistry, 2011, DOI: 10.1007/s00216-011-5238-2

  2. The investigation of advanced remote sensing, radiative transfer and inversion techniques for the measurement of atmospheric constituents

    NASA Technical Reports Server (NTRS)

    Deepak, Adarsh; Wang, Pi-Huan

    1985-01-01

    The research program is documented for developing space and ground-based remote sensing techniques performed during the period from December 15, 1977 to March 15, 1985. The program involved the application of sophisticated radiative transfer codes and inversion methods to various advanced remote sensing concepts for determining atmospheric constituents, particularly aerosols. It covers detailed discussions of the solar aureole technique for monitoring columnar aerosol size distribution, and the multispectral limb scattered radiance and limb attenuated radiance (solar occultation) techniques, as well as the upwelling scattered solar radiance method for determining the aerosol and gaseous characteristics. In addition, analytical models of aerosol size distribution and simulation studies of the limb solar aureole radiance technique and the variability of ozone at high altitudes during satellite sunrise/sunset events are also described in detail.

  3. ION-MOLECULAR EQUILIBRIUM TECHNIQUE APPLYED TO Cr O AND NiO ACTIVITY DETERMINATION. GIBBS ENERGY OF FORMATION OF

    E-print Network

    Rudnyi, Evgenii B.

    - 1 - ION-MOLECULAR EQUILIBRIUM TECHNIQUE APPLYED TO Cr O AND 2 3 NiO ACTIVITY DETERMINATION. GIBBS ENERGY OF FORMATION OF NiCr O . 2 4 RUDNYI E.B., KAIBICHEVA E.A., SIDOROV L.N. Department of Chemistry, Ur. Depart. Academy of science of USSR, Sverdlovsk, 620219, U.S.S.R. Short title - "GIBBS ENERGY

  4. www.BioTechniques.com285Vol. 50 | No. 5 | 2011 Pop quiz: What's the best molecular

    E-print Network

    Vertes, Akos

    Features www.BioTechniques.com285Vol. 50 | No. 5 | 2011 Tech News Pop quiz: What's the best abundance andmRNAexpressiondoserveasmolecular bellwethers of the cellular condition, these biomolecules turn over far too slowly. When it comes to cellular status, the molecular canary

  5. Capillary nano-immunoassays: advancing quantitative proteomics analysis, biomarker assessment, and molecular diagnostics.

    PubMed

    Chen, Jin-Qiu; Wakefield, Lalage M; Goldstein, David J

    2015-01-01

    There is an emerging demand for the use of molecular profiling to facilitate biomarker identification and development, and to stratify patients for more efficient treatment decisions with reduced adverse effects. In the past decade, great strides have been made to advance genomic, transcriptomic and proteomic approaches to address these demands. While there has been much progress with these large scale approaches, profiling at the protein level still faces challenges due to limitations in clinical sample size, poor reproducibility, unreliable quantitation, and lack of assay robustness. A novel automated capillary nano-immunoassay (CNIA) technology has been developed. This technology offers precise and accurate measurement of proteins and their post-translational modifications using either charge-based or size-based separation formats. The system not only uses ultralow nanogram levels of protein but also allows multi-analyte analysis using a parallel single-analyte format for increased sensitivity and specificity. The high sensitivity and excellent reproducibility of this technology make it particularly powerful for analysis of clinical samples. Furthermore, the system can distinguish and detect specific protein post-translational modifications that conventional Western blot and other immunoassays cannot easily capture. This review will summarize and evaluate the latest progress to optimize the CNIA system for comprehensive, quantitative protein and signaling event characterization. It will also discuss how the technology has been successfully applied in both discovery research and clinical studies, for signaling pathway dissection, proteomic biomarker assessment, targeted treatment evaluation and quantitative proteomic analysis. Lastly, a comparison of this novel system with other conventional immuno-assay platforms is performed. PMID:26048678

  6. Path Integral Molecular Dynamics within the Grand Canonical-like Adaptive Resolution Technique: Quantum-Classical Simulation of Liquid Water

    E-print Network

    Agarwal, Animesh

    2015-01-01

    Quantum effects due to the spatial delocalization of light atoms are treated in molecular simulation via the path integral technique. Among several methods, Path Integral (PI) Molecular Dynamics (MD) is nowadays a powerful tool to investigate properties induced by spatial delocalization of atoms; however computationally this technique is very demanding. The abovementioned limitation implies the restriction of PIMD applications to relatively small systems and short time scales. One possible solution to overcome size and time limitation is to introduce PIMD algorithms into the Adaptive Resolution Simulation Scheme (AdResS). AdResS requires a relatively small region treated at path integral level and embeds it into a large molecular reservoir consisting of generic spherical coarse grained molecules. It was previously shown that the realization of the idea above, at a simple level, produced reasonable results for toy systems or simple/test systems like liquid parahydrogen. Encouraged by previous results, in this ...

  7. Advanced imaging techniques II: using a compound microscope for photographing point-mount specimens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Digital imaging technology has revolutionized the practice photographing insects for scientific study. Herein described are lighting and mounting techniques designed for imaging micro Hymenoptera. Techniques described here are applicable to all small insects, as well as other invertebrates. The ke...

  8. Visceral Leishmaniasis: Advancements in Vaccine Development via Classical and Molecular Approaches

    PubMed Central

    Joshi, Sumit; Rawat, Keerti; Yadav, Narendra Kumar; Kumar, Vikash; Siddiqi, Mohammad Imran; Dube, Anuradha

    2014-01-01

    Visceral leishmaniasis (VL) or kala-azar, a vector-borne protozoan disease, shows endemicity in larger areas of the tropical, subtropical and the Mediterranean countries. WHO report suggested that an annual incidence of VL is nearly 200,000 to 400,000 cases, resulting in 20,000 to 30,000 deaths per year. Treatment with available anti-leishmanial drugs are not cost effective, with varied efficacies and higher relapse rate, which poses a major challenge to current kala-azar control program in Indian subcontinent. Therefore, a vaccine against VL is imperative and knowing the fact that recovered individuals developed lifelong immunity against re-infection, it is feasible. Vaccine development program, though time taking, has recently gained momentum with the emergence of omic era, i.e., from genomics to immunomics. Classical as well as molecular methodologies have been overtaken with alternative strategies wherein proteomics based knowledge combined with computational techniques (immunoinformatics) speed up the identification and detailed characterization of new antigens for potential vaccine candidates. This may eventually help in the designing of polyvalent synthetic and recombinant chimeric vaccines as an effective intervention measures to control the disease in endemic areas. This review focuses on such newer approaches being utilized for vaccine development against VL. PMID:25202307

  9. Removal of Lattice Imperfections that Impact the Optical Quality of Ti:Sapphire using Advanced Magnetorheological Finishing Techniques

    SciTech Connect

    Menapace, J A; Schaffers, K I; Bayramian, A J; Davis, P J; Ebbers, C A; Wolfe, J E; Caird, J A; Barty, C J

    2008-02-26

    Advanced magnetorheological finishing (MRF) techniques have been applied to Ti:sapphire crystals to compensate for sub-millimeter lattice distortions that occur during the crystal growing process. Precise optical corrections are made by imprinting topographical structure onto the crystal surfaces to cancel out the effects of the lattice distortion in the transmitted wavefront. This novel technique significantly improves the optical quality for crystals of this type and sets the stage for increasing the availability of high-quality large-aperture sapphire and Ti:sapphire optics in critical applications.

  10. Gas phase reaction kinetics at very low temperatures: recent advances on carbon chemistry using the CRESU technique

    NASA Astrophysics Data System (ADS)

    Canosa, A.

    2007-12-01

    The review describes briefly the chemistry of interstellar clouds and focusses on how bimolecular neutral-neutral reactions may influence its evolution. Experimental techniques that give information on the reactivity and the dynamics of these processes are presented with a special attention to the CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme) technique, which is the only one able to deliver rate coefficients at very low temperatures for reactions between two neutral partners. Recent advances concerning the reactivity of carbon-bearing molecules are described in more detail with a special attention to the reaction kinetics of C2 and C4H with small stable hydrocarbons.

  11. Investigation of Nalidixic Acid Resistance Mechanism in Salmonella enterica Using Molecular Simulation Techniques.

    PubMed

    Preethi, B; Shanthi, V; Ramanathan, K

    2015-09-01

    The emergence of nalidixic acid-resistant strains of Salmonella typhimurium remains to be a major public health problem. In particular, the substitution of Asn in place of Asp at the 87 loci in the GyrA of S. typhimurium was experimentally stated for nalidixic acid resistance. However, the data on the possible mechanism of nalidixic acid resistance are limited. In this study, I-Mutant2.0 and DUET program were employed to explore the impact of mutation on the stability of GyrA protein. Subsequently, molecular simulation techniques were employed to provide detailed information on the nalidixic acid-resistant associates with the D87N mutation in the GyrA of S. typhimurium. The binding free energy data depicts that nalidixic acid forms stable complex only with native-type GyrA than mutant (D87N) type GyrA protein. Moreover, our results theoretically suggest that hydrogen bonding formed by the Arg91 is certainly responsible for the GyrA of S. typhimurium drug selectivity. It is hoped that these evidences are immensely important for the development of new antibiotic and to overcome the nalidixic acid resistance in the near future. PMID:26208690

  12. Unraveling micro-mechanisms of grain boundary migration using molecular dynamics simulation and reaction path techniques

    NASA Astrophysics Data System (ADS)

    Lu, Shijing; Brenner, Donald

    2014-03-01

    Understanding grain boundary (GB) migration mechanisms plays a key role in understanding the deformation mechanics of nano-crystalline materials. Despite the many theories have been proposed, there still exists widespread disagreement in the research community. For instance, the normal direction diffusion model is often assumed in conventional grain growth models, but recent studies have suggested that shear-coupled grain boundary migration is dominate for high angle structures during stress driven dynamics. This study addresses the competition between the two mechanisms by using molecular dynamics simulations to characterize symmetric tilt grain boundary migration in response to an external driving force. The fundamental idea is to first determine an order parameters using principal coordinate analysis and then find the reaction pathways under different simulation conditions by minimum free energy path (MFEP) search techniques. Once the MFEP is found, the free energy profile for GB migration can be computed from thermodynamic integration. Our preliminary results show that migration behavior of a symmetric tilt grain boundary with various misorientation angles can be well represented by two order parameters, and surprisingly the MFEP for most misorientation GBs has a zigzag shape instead of the commonly observed a smoothed interface. This work was supported by a grant from the Office of Naval Research.

  13. Advanced in situ Spectroscopic Techniques And Their Applications In Environmental Biogeochemistry: Introduction To The Special Section

    EPA Science Inventory

    Understanding the molecular-scale complexities and interplay of chemical and biological processes of contaminants at solid, liquid, and gas interfaces is a fundamental and crucial element to enhance our understanding of anthropogenic environmental impacts. The ability to describ...

  14. The challenge of advanced model-based fdir techniques for aerospace systems: the 2011 situation

    NASA Astrophysics Data System (ADS)

    Zolghadri, A.

    2013-12-01

    For aerospace systems, advanced model-based Fault Detection, Identification, and Recovery (FDIR) challenges range from predesign and design stages for upcoming and new programs up to the improvement of the performance of in-service flying systems. However, today, their application to real aerospace world has remained extremely limited. The paper underlines the reasons for a widening gap between the advanced scientific FDIR methods being developed by the academic community and technological solutions demanded by the aerospace industry.

  15. Comparative study of four advanced 3d-conformal radiation therapy treatment planning techniques for head and neck cancer

    PubMed Central

    Herrassi, Mohamed Yassine; Bentayeb, Farida; Malisan, Maria Rosa

    2013-01-01

    For the head-and-neck cancer bilateral irradiation, intensity-modulated radiation therapy (IMRT) is the most reported technique as it enables both target dose coverage and organ-at-risk (OAR) sparing. However, during the last 20 years, three-dimensional conformal radiotherapy (3DCRT) techniques have been introduced, which are tailored to improve the classic shrinking field technique, as regards both planning target volume (PTV) dose conformality and sparing of OAR’s, such as parotid glands and spinal cord. In this study, we tested experimentally in a sample of 13 patients, four of these advanced 3DCRT techniques, all using photon beams only and a unique isocentre, namely Bellinzona, Forward-Planned Multisegments (FPMS), ConPas, and field-in-field (FIF) techniques. Statistical analysis of the main dosimetric parameters of PTV and OAR’s DVH’s as well as of homogeneity and conformity indexes was carried out in order to compare the performance of each technique. The results show that the PTV dose coverage is adequate for all the techniques, with the FPMS techniques providing the highest value for D95%; on the other hand, the best sparing of parotid glands is achieved using the FIF and ConPas techniques, with a mean dose of 26 Gy to parotid glands for a PTV prescription dose of 54 Gy. After taking into account both PTV coverage and parotid sparing, the best global performance was achieved by the FIF technique with results comparable to that of IMRT plans. This technique can be proposed as a valid alternative when IMRT equipment is not available or patient is not suitable for IMRT treatment. PMID:23776314

  16. Appropriate indication of fronto-orbital advancement by distraction osteogenesis in syndromic craniosynostosis: Beyond the conventional technique.

    PubMed

    Satoh, Kaneshige; Mitsukawa, Nobuyuki; Kubota, Yoshitaka; Akita, Shinsuku

    2015-12-01

    Currently the distraction technique could be very useful for posterior expansion in syndromic craniosynostosis. Even for fronto-orbital advancement (FOA), it is thought that distraction has the definitive advantage over the conventional technique. The authors describe the appropriate indication of distraction for FOA in our series of craniosynostosis patients. Since 1998, FOA by distraction has been used for 61 cases of simple and syndromic craniosynostosis. Among these, seven severe cases were extracted with a conspicuous craniofacial deformity with a multiple honeycomb appearance in 3DCT views. Early surgery for FOA by distraction to the extent possible was performed and a retrospective study was conducted. Seven children were identified. All of them exhibited a severe craniofacial deformity. Pfeiffer syndrome in 5 children and clover-leaf skull in two unidentified children were diagnosed. Mean age at surgery for FOA by distraction ranged 10-18 months. Mean operative time: 3-3.5 h. Blood loss: 230-320 mL. The mean advancement by distraction: 20-27 mm. We conclude FOA by distraction when a large amount of advancement is required for early severe cases as our series can be definitely one of the most appropriate candidates beyond the conventional technique, despite disadvantages. PMID:26463472

  17. Experimental and molecular docking studies on DNA binding interaction of adefovir dipivoxil: Advances toward treatment of hepatitis B virus infections

    NASA Astrophysics Data System (ADS)

    Shahabadi, Nahid; Falsafi, Monireh

    The toxic interaction of adefovir dipivoxil with calf thymus DNA (CT-DNA) was investigated in vitro under simulated physiological conditions by multi-spectroscopic techniques and molecular modeling study. The fluorescence spectroscopy and UV absorption spectroscopy indicated drug interacted with CT-DNA in a groove binding mode. The binding constant of UV-visible and the number of binding sites were 3.33 ± 0.2 × 104 L mol-1and 0.99, respectively. The fluorimetric studies showed that the reaction between the drug and CT-DNA is exothermic (?H = 34.4 kJ mol-1; ?S = 184.32 J mol-1 K-1). Circular dichroism spectroscopy (CD) was employed to measure the conformational change of CT-DNA in the presence of adefovir dipivoxil, which verified the groove binding mode. Furthermore, the drug induces detectable changes in its viscosity. The molecular modeling results illustrated that adefovir strongly binds to groove of DNA by relative binding energy of docked structure -16.83 kJ mol-1. This combination of multiple spectroscopic techniques and molecular modeling methods can be widely used in the investigation on the toxic interaction of small molecular pollutants and drugs with bio macromolecules, which contributes to clarify the molecular mechanism of toxicity or side effect in vivo.

  18. Experimental and molecular docking studies on DNA binding interaction of adefovir dipivoxil: advances toward treatment of hepatitis B virus infections.

    PubMed

    Shahabadi, Nahid; Falsafi, Monireh

    2014-05-01

    The toxic interaction of adefovir dipivoxil with calf thymus DNA (CT-DNA) was investigated in vitro under simulated physiological conditions by multi-spectroscopic techniques and molecular modeling study. The fluorescence spectroscopy and UV absorption spectroscopy indicated drug interacted with CT-DNA in a groove binding mode. The binding constant of UV-visible and the number of binding sites were 3.33±0.2×10(4) L mol(-1)and 0.99, respectively. The fluorimetric studies showed that the reaction between the drug and CT-DNA is exothermic (?H=34.4 kJ mol(-1); ?S=184.32 J mol(-1) K(-1)). Circular dichroism spectroscopy (CD) was employed to measure the conformational change of CT-DNA in the presence of adefovir dipivoxil, which verified the groove binding mode. Furthermore, the drug induces detectable changes in its viscosity. The molecular modeling results illustrated that adefovir strongly binds to groove of DNA by relative binding energy of docked structure -16.83 kJ mol(-1). This combination of multiple spectroscopic techniques and molecular modeling methods can be widely used in the investigation on the toxic interaction of small molecular pollutants and drugs with bio macromolecules, which contributes to clarify the molecular mechanism of toxicity or side effect in vivo. PMID:24548808

  19. Growth of organic molecular single crystal trans-stilbene by selective self seeding from vertical Bridgman technique

    NASA Astrophysics Data System (ADS)

    Arulchakkaravarthi, A.; Jayavel, P.; Santhanaraghavan, P.; Ramasamy, P.

    2002-01-01

    Single crystal growth of organic molecular materials by melt growth is plagued by serious difficulties owing to poor thermal conductivity, non-availability of good seed etc. Of all the melt growth techniques, Bridgman technique is widely preferred because of the low cost, versatility, easy adaptability, simple instrumentation etc. In the Bridgman technique the control on the formation/birth of the first single nuclei is still an art and in this paper we have proposed a selective self seeding technique for initiating single crystal growth. Trans-stilbene crystals have been grown using vertical Bridgman technique and using a modified ampoule design. Trans-stilbene crystal grown by using conventional method and by the present method were characterized for quality assessment by DCD and time resolution measurements.

  20. Adaptations of advanced safety and reliability techniques to petroleum and other industries

    NASA Technical Reports Server (NTRS)

    Purser, P. E.

    1974-01-01

    The underlying philosophy of the general approach to failure reduction and control is presented. Safety and reliability management techniques developed in the industries which have participated in the U.S. space and defense programs are described along with adaptations to nonaerospace activities. The examples given illustrate the scope of applicability of these techniques. It is indicated that any activity treated as a 'system' is a potential user of aerospace safety and reliability management techniques.

  1. [Application of molecular biology techniques in the identification of pathogenic fungi and the diagnosis of fungal infection].

    PubMed

    Li, Ruo-yu; Li, Dong-ming; Yu, Jin; Liu, Wei; Ji, Zhao-hui; Wang, Duan-li

    2004-10-01

    With the increasing incidence and mortality of fungal infection, the requirements for strict diagnostic approaches became a very urgent issue. Because of the traditional detective techniques, such as culture, gave poor diagnostic outcomes, the molecular biological techniques are expected to develop the potential diagnostic approaches. During the past decades, we have carried out serial studies on the molecular properties of pathogenic fungi, and we would like to review as following. Firstly, we applied several molecular tools in classification and identification of pathogenic fungi. We performed random amplification of polymorphic DNA (RAPD), restriction fragment length polymorphism (RFLP) and other techniques in studying the typing, to classify and identify the properties of Dermatophytes, Candida spp., Cryptococcus neoformans, Dematiaceous fungi, and Aspergillus spp. Interestingly, we found the same T. rubrum strain might infect different sites of the host, while a site-specificity displayed in T. mentagrophytes. This finding indicated the genetic discrepancies among the fungi. Beside, we also found that the E. dermatitis strains with different virulences possessed some discrepancies at gene level. We then developed a PCR-based molecular procedure to identify the novel species in Exophiala spp. As the applicable strategy, we also investigated the rDNA sequence properties in several fungi. And as a result, we submitted for the first time to GenBank the complete sequence of Aspergillus fumigatus rDNA/ITSI/ITSII, which provided the basis for designing the species-specific probes and for its further clinical applications. Secondly, we have tried to develop the molecular diagnostic approaches based on our DNA sequence data which were used for identification studies previously. By analyzing the DNA sequence of Aspergillus fumigatus rDNA/ITSI/ITSII, we developed a nested PCR method to detect Aspergillus fumigatus genes. Our preliminary results indicated that this PCR-based molecular approach has great importance in the diagnosis of invasive aspergillosis. We also designed the species-specific probes and then established several in situ hybridization procedures. We found these hybridization methods could get the positive rate up to 81% (13/16), which suggests that these methods have potential diagnostic value for invasive candidiasis and aspergillosis. Based on our experiences, we would conclude that the molecular biological techniques possess great value to investigate the biological properties of pathogenic fungi, and we are looking forward to see more and more molecular tools will be used in the pathogenic mechanisms of fungal infections and antifungal activity studies. PMID:15489939

  2. Australian endemic pest tephritids: genetic, molecular and microbial tools for improved Sterile Insect Technique

    PubMed Central

    2014-01-01

    Among Australian endemic tephritid fruit flies, the sibling species Bactrocera tryoni and Bactrocera neohumeralis have been serious horticultural pests since the introduction of horticulture in the nineteenth century. More recently, Bactrocera jarvisi has also been declared a pest in northern Australia. After several decades of genetic research there is now a range of classical and molecular genetic tools that can be used to develop improved Sterile Insect Technique (SIT) strains for control of these pests. Four-way crossing strategies have the potential to overcome the problem of inbreeding in mass-reared strains of B. tryoni. The ability to produce hybrids between B. tryoni and the other two species in the laboratory has proved useful for the development of genetically marked strains. The identification of Y-chromosome markers in B. jarvisi means that male and female embryos can be distinguished in any strain that carries a B. jarvisi Y chromosome. This has enabled the study of homologues of the sex-determination genes during development of B jarvisi and B. tryoni, which is necessary for the generation of genetic-sexing strains. Germ-line transformation has been established and a draft genome sequence for B. tryoni released. Transcriptomes from various species, tissues and developmental stages, to aid in identification of manipulation targets for improving SIT, have been assembled and are in the pipeline. Broad analyses of the microbiome have revealed a metagenome that is highly variable within and across species and defined by the environment. More specific analyses detected Wolbachia at low prevalence in the tropics but absent in temperate regions, suggesting a possible role for this endosymbiont in future control strategies. PMID:25470996

  3. Beyond the World Health Organization grading of infiltrating gliomas: advances in the molecular genetics of glioma classification

    PubMed Central

    Vigneswaran, Krishanthan; Neill, Stewart

    2015-01-01

    Background Traditional classification of diffuse infiltrating gliomas (DIGs) as World Health Organization (WHO) grades II-IV is based on histological features of a heterogeneous population of tumors with varying prognoses and treatments. Over the last decade, research efforts have resulted in a better understanding of the molecular basis of glioma formation as well as the genetic alterations commonly identified in diffuse gliomas. Methods A systematic review of the current literature related to advances in molecular phenotypes, mutations, and genomic analysis of gliomas was carried out using a PubMed search for these key terms. Data was studied and synthesized to generate a comprehensive review of glioma subclassification. Results This new data helps supplement the existing WHO grading scale by subtyping gliomas into specific molecular groups. The emerging molecular profile of diffuse gliomas includes the studies of gene expression and DNA methylation in different glioma subtypes. The discovery of novel mutations in isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) provides new biomarkers as points of stratification of gliomas based on prognosis and treatment response. Gliomas that harbor CpG island hypermethylator phenotypes constitute a subtype of glioma with improved survival. The difficulty of classifying oligodendroglial lineage of tumors can be aided with identification of 1p/19q codeletion. Glioblastomas (GBMs) previously described as primary or secondary can now be divided based on gene expression into proneural, mesenchymal, and classical subtypes and the identification of mutations in the promoter region of the telomerase reverse transcriptase (TERTp) have been correlated with poor prognosis in GBMs. Conclusions Incorporation of new molecular and genomic changes into the existing WHO grading of DIGs may provide better patient prognostication as well as advance the development of patient-specific treatments and clinical trials. PMID:26015937

  4. Advanced computational techniques for re-sequencing DNA with polymerase signaling assay

    E-print Network

    Shamir, Ron

    whose nucleic acid sequences are approximately known in advance. This is the case in validation in a target sequence, have been suggested for computa- tionally determining a polynucleotide sequence from its oligonucleotide content. We present here new methods that use such arrays for re-sequen- cing. Our methods

  5. FINAL REPORT. ADVANCED SENSING AND CONTROL TECHNIQUES TO FACILITATE SEMI-AUTONOMOUS DECOMMISSIONING

    EPA Science Inventory

    This research is intended to advance the technology of semi-autonomous teleoperated robotics as applied to Decontamination and Decommissioning (D&D) tasks. Specifically, research leading to a prototype dual-manipulatormobile work cell is underway. This cell is supported and enha...

  6. ADVANCED SENSING AND CONTROL TECHNIQUES TO FACILITATE SEMI-AUTONOMOUS DECOMMISSIONING

    EPA Science Inventory

    This research is intended to advance the technology of semiautonomous teleoperated robotics as applied to Decontamination and Decommissioning (D&D) tasks. Specifically, research leading to a prototype dual-manipulator mobile work cell is proposed. This cell is supported and enhan...

  7. Recent advances in electronic nose techniques for monitoring of fermentation process.

    PubMed

    Jiang, Hui; Zhang, Hang; Chen, Quansheng; Mei, Congli; Liu, Guohai

    2015-12-01

    Microbial fermentation process is often sensitive to even slight changes of conditions that may result in unacceptable end-product quality. Thus, the monitoring of the process is critical for discovering unfavorable deviations as early as possible and taking the appropriate measures. However, the use of traditional analytical techniques is often time-consuming and labor-intensive. In this sense, the most effective way of developing rapid, accurate and relatively economical method for quality assurance in microbial fermentation process is the use of novel chemical sensor systems. Electronic nose techniques have particular advantages in non-invasive monitoring of microbial fermentation process. Therefore, in this review, we present an overview of the most important contributions dealing with the quality control in microbial fermentation process using the electronic nose techniques. After a brief description of the fundamentals of the sensor techniques, some examples of potential applications of electronic nose techniques monitoring are provided, including the implementation of control strategies and the combination with other monitoring tools (i.e. sensor fusion). Finally, on the basis of the review, the electronic nose techniques are critically commented, and its strengths and weaknesses being highlighted. In addition, on the basis of the observed trends, we also propose the technical challenges and future outlook for the electronic nose techniques. PMID:26338367

  8. BB 493/593 Fall 2015 1 BB 493/593 Biochemistry Laboratory Molecular Techniques 1

    E-print Network

    Phone: 737-1773 E-mail: vanzeek@science.oregonstate.edu Office Hours: Wed 10-11 am and by appointment Dr. Adrian Gombart Phone: 737-8018 E-mail: Adrian.Gombart@oregonstate.edu Office Hours TBA Teaching Reaction (PCR) Molecular Cloning Site-Directed Mutagenesis DNA Sequencing Molecular Barcoding

  9. Time-frequency and advanced frequency estimation techniques for the investigation of bat echolocation calls.

    PubMed

    Kopsinis, Yannis; Aboutanios, Elias; Waters, Dean A; McLaughlin, Steve

    2010-02-01

    In this paper, techniques for time-frequency analysis and investigation of bat echolocation calls are studied. Particularly, enhanced resolution techniques are developed and/or used in this specific context for the first time. When compared to traditional time-frequency representation methods, the proposed techniques are more capable of showing previously unseen features in the structure of bat echolocation calls. It should be emphasized that although the study is focused on bat echolocation recordings, the results are more general and applicable to many other types of signal. PMID:20136233

  10. Advanced techniques for noise source identification on a large generator unit

    SciTech Connect

    Williams, R.G.D. ); Yang, S.J. )

    1993-03-01

    Power station acoustic noise assessment, which has experienced increased environmental awareness and subsequently more stringent legislation for a number of years, has received and added stimulus due to the recent advent of powerful measurement and analysis techniques including sound intensity and coherence. These experimental techniques are explained and results, for a generator unit, illustrate their value in providing a unique, correlated insight into noise problems. This includes noise quantification, full explanation of site sound pressure level in terms of the various influences and major noise source identification. These techniques are widely applicable and an invaluable aid to any industrial noise problem.

  11. Microprobing the Molecular Spatial Distribution and Structural Architecture of Feed-type Sorghum Seed Tissue (Sorghum Bicolor L.) using the Synchrotron Radiation Infrared Microspectroscopy Technique

    SciTech Connect

    P Yu

    2011-12-31

    Sorghum seed (Sorghum bicolor L.) has unique degradation and fermentation behaviours compared with other cereal grains such as wheat, barley and corn. This may be related to its cell and cell-wall architecture. The advanced synchrotron radiation infrared microspectroscopy (SR-IMS) technique enables the study of cell or living cell biochemistry within cellular dimensions. The objective of this study was to use the SR-IMS imaging technique to microprobe molecular spatial distribution and cell architecture of the sorghum seed tissue comprehensively. High-density mapping was carried out using SR-IMS on beamline U2B at the National Synchrotron Light Source (Brookhaven National Laboratory, NY, USA). Molecular images were systematically recorded from the outside to the inside of the seed tissue under various chemical functional groups and their ratios [peaks at {approx}1725 (carbonyl C=O ester), 1650 (amide I), 1657 (protein secondary structure {alpha}-helix), 1628 (protein secondary structure {beta}-sheet), 1550 (amide II), 1515 (aromatic compounds of lignin), 1428, 1371, 1245 (cellulosic compounds in plant seed tissue), 1025 (non-structural CHO, starch granules), 1246 (cellulosic material), 1160 (CHO), 1150 (CHO), 1080 (CHO), 930 (CHO), 860 (CHO), 3350 (OH and NH stretching), 2960 (CH{sub 3} anti-symmetric), 2929 (CH{sub 2} anti-symmetric), 2877 (CH{sub 3} symmetric) and 2848 cm{sup -1} (CH{sub 2} asymmetric)]. The relative protein secondary structure {alpha}-helix to {beta}-sheet ratio image, protein amide I to starch granule ratio image, and anti-symmetric CH{sub 3} to CH{sub 2} ratio image were also investigated within the intact sorghum seed tissue. The results showed unique cell architecture, and the molecular spatial distribution and intensity in the sorghum seed tissue (which were analyzed through microprobe molecular imaging) were generated using SR-IMS. This imaging technique and methodology has high potential and could be used for scientists to develop specific cereal grain varieties with targeted food and feed quality, and can also be used to monitor the degree of grain maturity, grain damage, the fate of organic contaminants and the effect of chemical treatment on plant and grain seeds.

  12. Electrical test structures and measurement techniques for the characterisation of advanced photomasks 

    E-print Network

    Tsiamis, Andreas

    2010-01-01

    Existing photomask metrology is struggling to keep pace with the rapid reduction of IC dimensions as traditional measurement techniques are being stretched to their limits. This thesis examines the use of on-mask probable ...

  13. Integration of Micro Patterning Techniques into Volatile Functional Materials and Advanced Devices 

    E-print Network

    Hong, Jung M.

    2010-07-14

    -molecules and organic materials), micro-contact printing and shadow mask methods are investigated. A novel micro-contact printing technique was developed to generate micro patterns of volatile materials with variable size and density. A PDMS (Polydimethylsiloxane) stamp...

  14. Advanced fault diagnosis techniques and their role in preventing cascading blackouts 

    E-print Network

    Zhang, Nan

    2007-04-25

    This dissertation studied new transmission line fault diagnosis approaches using new technologies and proposed a scheme to apply those techniques in preventing and mitigating cascading blackouts. The new fault diagnosis approaches are based on two...

  15. A numerical technique for calculation of the noise of high-speed propellers with advanced blade geometry

    NASA Technical Reports Server (NTRS)

    Nystrom, P. A.; Farassat, F.

    1980-01-01

    A numerical technique and computer program were developed for the prediction of the noise of propellers with advanced geometry. The blade upper and lower surfaces are described by a curvilinear coordinate system, which was also used to divide the blade surfaces into panels. Two different acoustic formulations in the time domain were used to improve the speed and efficiency of the noise calculations: an acoustic formualtion with the Doppler factor singularity for panels moving at subsonic speeds and the collapsing sphere formulation for panels moving at transonic or supersonic speeds. This second formulation involves a sphere which is centered at the observer position and whose radius decreases at the speed of sound. The acoustic equation consisted of integrals over the curve of intersection for both the sphere and the panels on the blade. Algorithms used in some parts of the computer program are discussed. Comparisons with measured acoustic data for two model high speed propellers with advanced geometry are also presented.

  16. Advanced imaging technique for automated classification of casts and crystals in urine

    NASA Astrophysics Data System (ADS)

    Paranjape, Amit S.; Castleman, Kenneth; Milner, Thomas E.; Rylander, H. Grady

    2007-02-01

    We present the development and demonstration of a novel technique for microscopic analysis of urine particles. Casts and crystals in urine are indicative of clinically important abnormalities. Current urinalysis techniques using flow cytometry and image analysis are limited by their inability to detect, identify and classify crystals and casts. Casts, crystals and yeast cells reported by current automated urine particle analyzers must be confirmed by a second microscopic review involving a human operator to prevent false positives. Human examination of suspect urine samples is resource intensive and time consuming. We introduce a new imaging method to add functionality for recognition of casts and crystals in urine. Our approach uses a polarization microscopy technique to aid classification of crystals, casts and other urine particles. Crystals and casts in urine exhibit unique interference patterns when imaged using a fixed polarizer and analyzer in a crossed configuration. These interference patterns are a measure of birefringence (retardation angle) of the cast or crystal being imaged. Preliminary experiments indicate that uric acid shows a polarization color, and larger crystals exhibit a series of concentric black lines. We show that these unique 'signatures' when used in conjunction with a hierarchical pattern recognition technique can reliably classify the analytes with improved accuracy. The new imaging technique combined with the classification algorithm can address the shortcomings of current urinalysis techniques; and provide quicker and more accurate results.

  17. External Magnetic Field Reduction Techniques for the Advanced Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Niedra, Janis M.; Geng, Steven M.

    2013-01-01

    Linear alternators coupled to high efficiency Stirling engines are strong candidates for thermal-to-electric power conversion in space. However, the magnetic field emissions, both AC and DC, of these permanent magnet excited alternators can interfere with sensitive instrumentation onboard a spacecraft. Effective methods to mitigate the AC and DC electromagnetic interference (EMI) from solenoidal type linear alternators (like that used in the Advanced Stirling Convertor) have been developed for potential use in the Advanced Stirling Radioisotope Generator. The methods developed avoid the complexity and extra mass inherent in data extraction from multiple sensors or the use of shielding. This paper discusses these methods, and also provides experimental data obtained during breadboard testing of both AC and DC external magnetic field devices.

  18. Advanced techniques for the storage and use of very large, heterogeneous spatial databases

    NASA Technical Reports Server (NTRS)

    Peuquet, Donna J.

    1987-01-01

    Progress is reported in the development of a prototype knowledge-based geographic information system. The overall purpose of this project is to investigate and demonstrate the use of advanced methods in order to greatly improve the capabilities of geographic information system technology in the handling of large, multi-source collections of spatial data in an efficient manner, and to make these collections of data more accessible and usable for the Earth scientist.

  19. Three dimensional imaging technique suitable for the measurements of the internal energies of asymmetrical diatomic molecular ions

    NASA Astrophysics Data System (ADS)

    Sauza, J. B.; Panchenko, D. I.; Duot, A. C.; Strom, R. A.; Andrianarijaona, V. M.

    2015-05-01

    We propose a three dimensional imaging technique that could be used to measure the internal energy of asymmetrical diatomic molecular ions such as HeH+ and CO+. The detection scheme is similar to the one used for symmetrical diatomic molecular ions, which accesses the internal energy of the ion through the kinetic energy release in a resonant dissociative charge transfer (see for instance). In that technique, the fragments hit two detectors which send the positions of the impacts along with the difference between the times of impacts to a computer. The computed kinetic energy release is related to the vibrational excitation level of the initial molecular ion. In the case of an asymmetrical ion, the lighter fragment has a higher recoil velocity and goes further away transversally from the center of mass direction. The heavier fragment would not hit the first detector if the beam is judiciously misaligned. Therefore, we make distinction between the two particles. Details of the technique will be presented. Authors wish to give special thanks to Pacific Union College Student Senate for their financial support.

  20. Path integral molecular dynamics within the grand canonical-like adaptive resolution technique: Simulation of liquid water

    NASA Astrophysics Data System (ADS)

    Agarwal, Animesh; Delle Site, Luigi

    2015-09-01

    Quantum effects due to the spatial delocalization of light atoms are treated in molecular simulation via the path integral technique. Among several methods, Path Integral (PI) Molecular Dynamics (MD) is nowadays a powerful tool to investigate properties induced by spatial delocalization of atoms; however, computationally this technique is very demanding. The above mentioned limitation implies the restriction of PIMD applications to relatively small systems and short time scales. One of the possible solutions to overcome size and time limitation is to introduce PIMD algorithms into the Adaptive Resolution Simulation Scheme (AdResS). AdResS requires a relatively small region treated at path integral level and embeds it into a large molecular reservoir consisting of generic spherical coarse grained molecules. It was previously shown that the realization of the idea above, at a simple level, produced reasonable results for toy systems or simple/test systems like liquid parahydrogen. Encouraged by previous results, in this paper, we show the simulation of liquid water at room conditions where AdResS, in its latest and more accurate Grand-Canonical-like version (GC-AdResS), is merged with two of the most relevant PIMD techniques available in the literature. The comparison of our results with those reported in the literature and/or with those obtained from full PIMD simulations shows a highly satisfactory agreement.

  1. Advancements in subsea intervention and construction techniques for dropped object protection, pipeline stabilization and grouting related activities

    SciTech Connect

    Hudson, J.W.

    1998-12-31

    This paper is a state of the art review of Subsea Intervention and Construction Techniques using ROVs for pipeline protection, stabilization and grouting-related activities. It identifies the important stages involved in the various processes and reviews the problems experienced. Technical advances and improvements over the years have, in certain instances, produced new problems, these are highlighted and discussed. Common problem areas are investigated and the remedial measures used to overcome these are discussed, together with their effect on the final integrity of the particular product or service affected.

  2. POC-SCALE TESTING OF AN ADVANCED FINE COAL DEWATERING EQUIPMENT/TECHNIQUE

    SciTech Connect

    X.H. Wang; J. Wiseman; D.J. Sung; D. McLean; William Peters; Jim Mullins; John Hugh; G. Evans; Vince Hamilton; Kenneth Robinette; Tim Krim; Michael Fleet

    1999-08-01

    Dewatering of ultra-fine (minus 150 {micro}m) coal slurry to less than 20% moisture is difficult using the conventional dewatering techniques. The main objective of the project was to evaluate a novel surface modification technique, which utilizes the synergistic effect of metal ions and surfactants in combination for the dewatering of ultra-fine clean-coal slurries using various dewatering techniques on a proof-of-concept (POC) scale of 0.5 to 2 tons per hour. The addition of conventional reagents and the application of coal surface modification technique were evaluated using vacuum filtration, hyperbaric (pressure) filtration, ceramic plate filtration and screen-bowl centrifuge techniques. The laboratory and pilot-scale dewatering studies were conducted using the fine-size, clean-coal slurry produced in the column flotation circuit at the Powell Mountain Coal Company, St. Charles, VA. The pilot-scale studies were conducted at the Mayflower preparation plant in St. Charles, VA. The program consisted of nine tasks, namely, Task 1--Project Work Planning, Task 2--Laboratory Testing, Task 3--Engineering Design, Task 4--Procurement and Fabrication, Task 5--Installation and Shakedown, Task 6--System Operation, Task 7--Process Evaluation, Task 8--Equipment Removal, and Task 9--Reporting.

  3. Visualization of delamination in composite materials utilizing advanced X-ray imaging techniques

    NASA Astrophysics Data System (ADS)

    Vavrik, D.; Jakubek, J.; Jandejsek, I.; Krejci, F.; Kumpova, I.; Zemlicka, J.

    2015-04-01

    This work is focused on the development of instrumental radiographic methods for detection of delaminations in layered carbon fibre reinforced plastic composites used in the aerospace industry. The main limitation of current visualisation techniques is a very limited possibility to image so-called closed delaminations in which delaminated layers are in contact practically with no physical gap. In this contribution we report the development of innovative methods for closed delamination detection using an X-ray phase contrast technique for which the distance between delamination surfaces is not relevant. The approach is based on the energetic sensitivity of phase-enhanced radiography. Based on the applied methodology, we can distinguish both closed and open delamination. Further we have demonstrated the possibility to visualise open delaminations characterised by a physical gap between delaminated layers. This delamination type was successfully identified and visualized utilizing a high resolution and computed tomography table-top technique based on proper beam-hardening effect correction.

  4. Advanced analysis technique for the evaluation of linear alternators and linear motors

    NASA Technical Reports Server (NTRS)

    Holliday, Jeffrey C.

    1995-01-01

    A method for the mathematical analysis of linear alternator and linear motor devices and designs is described, and an example of its use is included. The technique seeks to surpass other methods of analysis by including more rigorous treatment of phenomena normally omitted or coarsely approximated such as eddy braking, non-linear material properties, and power losses generated within structures surrounding the device. The technique is broadly applicable to linear alternators and linear motors involving iron yoke structures and moving permanent magnets. The technique involves the application of Amperian current equivalents to the modeling of the moving permanent magnet components within a finite element formulation. The resulting steady state and transient mode field solutions can simultaneously account for the moving and static field sources within and around the device.

  5. Advanced NMR-based techniques for pore structure analysis of coal. Final project report

    SciTech Connect

    Smith, D.M.; Hua, D.W.

    1996-02-01

    During the 3 year term of the project, new methods have been developed for characterizing the pore structure of porous materials such as coals, carbons, and amorphous silica gels. In general, these techniques revolve around; (1) combining multiple techniques such as small-angle x-ray scattering (SAXS) and adsorption of contrast-matched adsorbates or {sup 129}Xe NMR and thermoporometry (the change in freezing point with pore size), (2) combining adsorption isotherms over several pressure ranges to obtain a more complete description of pore filling, or (3) applying NMR ({sup 129}Xe, {sup 14}N{sub 2}, {sup 15}N{sub 2}) techniques with well-defined porous solids with pores in the large micropore size range (>1 nm).

  6. Advanced Analytical Techniques for the Measurement of Nanomaterials in Food and Agricultural Samples: A Review

    PubMed Central

    Bandyopadhyay, Susmita; Peralta-Videa, Jose R.; Gardea-Torresdey, Jorge L.

    2013-01-01

    Abstract Nanotechnology offers substantial prospects for the development of state-of-the-art products and applications for agriculture, water treatment, and food industry. Profuse use of nanoproducts will bring potential benefits to farmers, the food industry, and consumers, equally. However, after end-user applications, these products and residues will find their way into the environment. Therefore, discharged nanomaterials (NMs) need to be identified and quantified to determine their ecotoxicity and the levels of exposure. Detection and characterization of NMs and their residues in the environment, particularly in food and agricultural products, have been limited, as no single technique or method is suitable to identify and quantify NMs. In this review, we have discussed the available literature concerning detection, characterization, and measurement techniques for NMs in food and agricultural matrices, which include chromatography, flow field fractionation, electron microscopy, light scattering, and autofluorescence techniques, among others. PMID:23483065

  7. Advanced atomic force microscopy techniques for characterizing the properties of cellulosic nanomaterials

    NASA Astrophysics Data System (ADS)

    Wagner, Ryan Bradley

    The measurement of nanomechanical properties is of great interest to science and industry. Key to progress in this area is the development of new techniques and analysis methods to identify, measure, and quantify these properties. In this dissertation, new data analysis methods and experimental techniques for measuring nanomechanical properties with the atomic force microscope (AFM) are considered. These techniques are then applied to the study of cellulose nanoparticles, an abundant, plant derived nanomaterial. Quantifying uncertainty is a prerequisite for the manufacture of reliable nano-engineered materials and products. However, rigorous uncertainty quantification is rarely applied for material property measurements with the AFM. A framework is presented to ascribe uncertainty to local nanomechanical properties of any nanoparticle or surface measured with the AFM by taking into account the main uncertainty sources inherent in such measurements. This method is demonstrated by quantifying uncertainty in force displacement AFM based measurements of the transverse elastic modulus of tunicate cellulose nanocrystals. Next, a more comprehensive study of different types of cellulose nanoparticles is undertaken with contact resonance (CR) AFM. CR-AFM is a dynamic AFM technique that exploits the resonance frequency of the AFM cantilever while it is permanent contact with the sample surface to predict nanomechanical properties. This technique offers improved measurement sensitivity over static AFM methods for some material systems. The effects of cellulose source material and processing technique on the properties of cellulose nanoparticles are compared. Finally, dynamic AFM cantilever vibration shapes are studied. Many AFM modes exploit the dynamic response of a cantilever in permanent contact with a sample to extract local material properties. A common challenge to these modes is that they assume a certain shape of cantilever vibration, which is not accessible in standard AFM measurements. A method is presented to measure these vibrational shapes. This method is then used to study CR-AFM, providing unique insight into CR-AFM modeling and experiments. The methodologies discussed in this dissertation provide improved capability to measure nanomechanical properties with the AFM.

  8. Image enhancement and advanced information extraction techniques for ERTS-1 data

    NASA Technical Reports Server (NTRS)

    Malila, W. A. (principal investigator); Nalepka, R. F.; Sarno, J. E.

    1975-01-01

    The author has identified the following significant results. It was demonstrated and concluded that: (1) the atmosphere has significant effects on ERTS MSS data which can seriously degrade recognition performance; (2) the application of selected signature extension techniques serve to reduce the deleterious effects of both the atmosphere and changing ground conditions on recognition performance; and (3) a proportion estimation algorithm for overcoming problems in acreage estimation accuracy resulting from the coarse spatial resolution of the ERTS MSS, was able to significantly improve acreage estimation accuracy over that achievable by conventional techniques, especially for high contrast targets such as lakes and ponds.

  9. Optical diagnostics of gas-dynamic flows using advanced laser measurement techniques

    NASA Technical Reports Server (NTRS)

    Gross, K. P.

    1985-01-01

    Using laser-induced fluorescence to probe nitrogen flows seeded with small amounts of nitric oxide, simultaneous measurements of all three thermodynamic scalar quantities temperature, density, and pressure, were demonstrated in a supersonic turbulent boundary layer. Instrumental uncertainty is 1% for temperature and 2% for density and pressure, making the techniques suitable for measurements of turbulent fluctuations. This technology is currently being transferred to an experimental program designed to use these optical techniques in conjunction with traditional methods to make measurements in turbulent flowfields that were not possible before. A detailed descritpion of the research progress and pertinent results are presented.

  10. Development of a real-time aeroperformance analysis technique for the X-29A advanced technology demonstrator

    NASA Technical Reports Server (NTRS)

    Ray, R. J.; Hicks, J. W.; Alexander, R. I.

    1988-01-01

    The X-29A advanced technology demonstrator has shown the practicality and advantages of the capability to compute and display, in real time, aeroperformance flight results. This capability includes the calculation of the in-flight measured drag polar, lift curve, and aircraft specific excess power. From these elements many other types of aeroperformance measurements can be computed and analyzed. The technique can be used to give an immediate postmaneuver assessment of data quality and maneuver technique, thus increasing the productivity of a flight program. A key element of this new method was the concurrent development of a real-time in-flight net thrust algorithm, based on the simplified gross thrust method. This net thrust algorithm allows for the direct calculation of total aircraft drag.

  11. Assessing public transport travel behaviour from smart card data with advanced data mining techniques AGARD, Bruno; PARTOVI-NIA, Vahid; TRPANIER, Martin

    E-print Network

    Partovi Nia, Vahid

    Assessing public transport travel behaviour from smart card data with advanced data mining, Brazil 1 ASSESSING PUBLIC TRANSPORT TRAVEL BEHAVIOUR FROM SMART CARD DATA WITH ADVANCED DATA MINING innovative data mining techniques for grouping and characterising public transport users. This study uses

  12. Advanced microprocessor based power protection system using artificial neural network techniques

    SciTech Connect

    Chen, Z.; Kalam, A.; Zayegh, A.

    1995-12-31

    This paper describes an intelligent embedded microprocessor based system for fault classification in power system protection system using advanced 32-bit microprocessor technology. The paper demonstrates the development of protective relay to provide overcurrent protection schemes for fault detection. It also describes a method for power fault classification in three-phase system based on the use of neural network technology. The proposed design is implemented and tested on a single line three phase power system in power laboratory. Both the hardware and software development are described in detail.

  13. Advanced computer techniques for inverse modeling of electric current in cardiac tissue

    SciTech Connect

    Hutchinson, S.A.; Romero, L.A.; Diegert, C.F.

    1996-08-01

    For many years, ECG`s and vector cardiograms have been the tools of choice for non-invasive diagnosis of cardiac conduction problems, such as found in reentrant tachycardia or Wolff-Parkinson-White (WPW) syndrome. Through skillful analysis of these skin-surface measurements of cardiac generated electric currents, a physician can deduce the general location of heart conduction irregularities. Using a combination of high-fidelity geometry modeling, advanced mathematical algorithms and massively parallel computing, Sandia`s approach would provide much more accurate information and thus allow the physician to pinpoint the source of an arrhythmia or abnormal conduction pathway.

  14. POC-scale testing of an advanced fine coal dewatering equipment/technique. Quarterly progress report, July - September 1996

    SciTech Connect

    Tao, D.; Groppo, J.G.; Parekh, B.K.

    1996-10-01

    The advanced fine-coal cleaning techniques such as column flotation, recovers a low-ash ultra-fine size clean-coal product. However, economical dewatering of the clean coal product to less than 20 percent moisture using conventional technology is difficult. This research program objective is to evaluate a novel coal surface modification technique developed at the University of Kentucky Center for Applied Energy Research in conjunction with conventional and advanced dewatering technique at a pilot scale. The study which is in progress is being conducted at the Powell Mountain Coal Company`s Mayflower preparation plant located in St. Charles, VA. During this quarter laboratory dewatering studies were conducted using a 4-in diameter laboratory chemical centrifuge. The baseline data provided a filter cake with about 32% moisture. Addition of 0.3 kg/t of a cationic surfactant lowered the moisture to 29%. Addition of anionic and non-ionic surfactant was not effective in reducing the filter cake moisture content. In the pilot scale studies, a comparison was conducted between the high pressure and vacuum dewatering techniques. The base line data with high pressure and vacuum filtration provided filter cakes with 23.6% and 27.8% moisture, respectively. Addition of 20 g/t of cationic flocculent provided 21% filter cake moisture using the high pressure filter. A 15% moisture filter cake was obtained using 1.5 kg/t of non-ionic surfactant. Vacuum filter provided about 23% to 25% moisture product with additional reagents. The high pressure filter processed about 3 to 4 times more solids compared to vacuum filter.

  15. Advance development of a technique for characterizing the thermomechanical properties of thermally stable polymers

    NASA Technical Reports Server (NTRS)

    Gillham, J. K.; Stadnicki, S. J.; Hazony, Y.

    1974-01-01

    The torsional braid experiment has been interfaced with a centralized hierarchical computing system for data acquisition and data processing. Such a system, when matched by the appropriate upgrading of the monitoring techniques, provides high resolution thermomechanical spectra of rigidity and damping, and their derivatives with respect to temperature.

  16. An advanced test technique to quantify thermomechanical fatigue damage accumulation in composite materials

    NASA Technical Reports Server (NTRS)

    Castelli, Michael G.

    1993-01-01

    A mechanical test technique was developed to assist in quantifying the accumulation of damage in composite materials during thermomechanical fatigue (TMF) cycling. This was accomplished by incorporating definitive elastic mechanical property measurements into an ongoing load-controlled TMF test without disturbing the test specimen or significantly altering the test conditions. The technique allows two fundamental composite properties consisting of the isothermal elastic static moduli and the macroscopic coefficient of thermal expansion (CTE) to be measured and collected as functions of the TMF cycles. The specific implementation was incorporated into the commonly employed idealized in-phase and out-of-phase TMF cycles. However, the techniques discussed could be easily implemented into any form of load-controlled TMF mission cycle. By quantifying the degradations of these properties, tremendous insights are gained concerning the progression of macroscopic composite damage and often times the progression of damage within a given constituent. This information should also be useful for the characterization and essential for the verification of analytical damage modeling methodologies. Several examples utilizing this test technique are given for three different fiber lay-ups of titanium metal matrix composites.

  17. Teachers' Questioning Techniques in Advanced Level Chemistry Lessons: A Tanzanian Perspective

    ERIC Educational Resources Information Center

    Kira, Ernest; Komba, Sotco; Kafanabo, Eugenia; Tilya, Frank

    2013-01-01

    This study investigated the extent to which teachers' questioning techniques and the way teachers handled students' responses facilitated students' learning and promoted their thinking skills. The study focused on three secondary schools in Dar es Salaam. The data collection process involved classroom observations during chemistry…

  18. Advanced Techniques for Reservoir Simulation and Modeling of Non-Conventional Wells

    SciTech Connect

    Durlofsky, Louis J.; Aziz, Khalid

    2001-08-23

    Research results for the second year of this project on the development of improved modeling techniques for non-conventional (e.g., horizontal, deviated or multilateral) wells were presented. The overall program entails the development of enhanced well modeling and general simulation capabilities. A general formulation for black-oil and compositional reservoir simulation was presented.

  19. Using Essential Oils to Teach Advanced-Level Organic Chemistry Separation Techniques and Spectroscopy

    ERIC Educational Resources Information Center

    Bott, Tina M.; Wan, Hayley

    2013-01-01

    Students sometimes have difficulty grasping the importance of when and how basic distillation techniques, column chromatography, TLC, and basic spectroscopy (IR and NMR) can be used to identify unknown compounds within a mixture. This two-part experiment uses mixtures of pleasant-smelling, readily available terpenoid compounds as unknowns to…

  20. Carbon dioxide capture and separation techniques for advanced power generation point sources

    SciTech Connect

    Pennline, H.W.; Luebke, D.R.; Morsi, B.I.; Heintz, Y.J.; Jones, K.L.; Ilconich, J.B.

    2006-09-01

    The capture/separation step for carbon dioxide (CO2) from large-point sources is a critical one with respect to the technical feasibility and cost of the overall carbon sequestration scenario. For large-point sources, such as those found in power generation, the carbon dioxide capture techniques being investigated by the in-house research area of the National Energy Technology Laboratory possess the potential for improved efficiency and costs as compared to more conventional technologies. The investigated techniques can have wide applications, but the research has focused on capture/separation of carbon dioxide from flue gas (postcombustion from fossil fuel-fired combustors) and from fuel gas (precombustion, such as integrated gasification combined cycle – IGCC). With respect to fuel gas applications, novel concepts are being developed in wet scrubbing with physical absorption; chemical absorption with solid sorbents; and separation by membranes. In one concept, a wet scrubbing technique is being investigated that uses a physical solvent process to remove CO2 from fuel gas of an IGCC system at elevated temperature and pressure. The need to define an ideal solvent has led to the study of the solubility and mass transfer properties of various solvents. Fabrication techniques and mechanistic studies for hybrid membranes separating CO2 from the fuel gas produced by coal gasification are also being performed. Membranes that consist of CO2-philic silanes incorporated into an alumina support or ionic liquids encapsulated into a polymeric substrate have been investigated for permeability and selectivity. An overview of two novel techniques is presented along with a research progress status of each technology.

  1. Advanced model-based FDIR techniques for aerospace systems: Today challenges and opportunities

    NASA Astrophysics Data System (ADS)

    Zolghadri, Ali

    2012-08-01

    This paper discusses some trends and recent advances in model-based Fault Detection, Isolation and Recovery (FDIR) for aerospace systems. The FDIR challenges range from pre-design and design stages for upcoming and new programs, to improvement of the performance of in-service flying systems. For space missions, optimization of flight conditions and safe operation is intrinsically related to GNC (Guidance, Navigation & Control) system of the spacecraft and includes sensors and actuators monitoring. Many future space missions will require autonomous proximity operations including fault diagnosis and the subsequent control and guidance recovery actions. For upcoming and future aircraft, one of the main issues is how early and robust diagnosis of some small and subtle faults could contribute to the overall optimization of aircraft design. This issue would be an important factor for anticipating the more and more stringent requirements which would come in force for future environmentally-friendlier programs. The paper underlines the reasons for a widening gap between the advanced scientific FDIR methods being developed by the academic community and technological solutions demanded by the aerospace industry.

  2. Advances in iterative non-uniformity correction techniques for infrared scene projection

    NASA Astrophysics Data System (ADS)

    Danielson, Tom; Franks, Greg; LaVeigne, Joe; Prewarski, Marcus; Nehring, Brian

    2015-05-01

    Santa Barbara Infrared (SBIR) is continually developing improved methods for non-uniformity correction (NUC) of its Infrared Scene Projectors (IRSPs) as part of its comprehensive efforts to achieve the best possible projector performance. The most recent step forward, Advanced Iterative NUC (AI-NUC), improves upon previous NUC approaches in several ways. The key to NUC performance is achieving the most accurate possible input drive-to-radiance output mapping for each emitter pixel. This requires many highly-accurate radiance measurements of emitter output, as well as sophisticated manipulation of the resulting data set. AI-NUC expands the available radiance data set to include all measurements made of emitter output at any point. In addition, it allows the user to efficiently manage that data for use in the construction of a new NUC table that is generated from an improved fit of the emitter response curve. Not only does this improve the overall NUC by offering more statistics for interpolation than previous approaches, it also simplifies the removal of erroneous data from the set so that it does not propagate into the correction tables. AI-NUC is implemented by SBIR's IRWindows4 automated test software as part its advanced turnkey IRSP product (the Calibration Radiometry System or CRS), which incorporates all necessary measurement, calibration and NUC table generation capabilities. By employing AI-NUC on the CRS, SBIR has demonstrated the best uniformity results on resistive emitter arrays to date.

  3. Large ensemble modeling of last deglacial retreat of the West Antarctic Ice Sheet: comparison of simple and advanced statistical techniques

    NASA Astrophysics Data System (ADS)

    Pollard, D.; Chang, W.; Haran, M.; Applegate, P.; DeConto, R.

    2015-11-01

    A 3-D hybrid ice-sheet model is applied to the last deglacial retreat of the West Antarctic Ice Sheet over the last ~ 20 000 years. A large ensemble of 625 model runs is used to calibrate the model to modern and geologic data, including reconstructed grounding lines, relative sea-level records, elevation-age data and uplift rates, with an aggregate score computed for each run that measures overall model-data misfit. Two types of statistical methods are used to analyze the large-ensemble results: simple averaging weighted by the aggregate score, and more advanced Bayesian techniques involving Gaussian process-based emulation and calibration, and Markov chain Monte Carlo. Results for best-fit parameter ranges and envelopes of equivalent sea-level rise with the simple averaging method agree quite well with the more advanced techniques, but only for a large ensemble with full factorial parameter sampling. Best-fit parameter ranges confirm earlier values expected from prior model tuning, including large basal sliding coefficients on modern ocean beds. Each run is extended 5000 years into the "future" with idealized ramped climate warming. In the majority of runs with reasonable scores, this produces grounding-line retreat deep into the West Antarctic interior, and the analysis provides sea-level-rise envelopes with well defined parametric uncertainty bounds.

  4. Advanced Materials and Fabrication Techniques for the Orion Attitude Control Motor

    NASA Technical Reports Server (NTRS)

    Gorti, Sridhar; Holmes, Richard; O'Dell, John; McKechnie, Timothy; Shchetkovskiy, Anatoliy

    2013-01-01

    Rhenium, with its high melting temperature, excellent elevated temperature properties, and lack of a ductile-to-brittle transition temperature (DBTT), is ideally suited for the hot gas components of the ACM (Attitude Control Motor), and other high-temperature applications. However, the high cost of rhenium makes fabricating these components using conventional fabrication techniques prohibitive. Therefore, near-net-shape forming techniques were investigated for producing cost-effective rhenium and rhenium alloy components for the ACM and other propulsion applications. During this investigation, electrochemical forming (EL-Form ) techniques were evaluated for producing the hot gas components. The investigation focused on demonstrating that EL-Form processing techniques could be used to produce the ACM flow distributor. Once the EL-Form processing techniques were established, a representative rhenium flow distributor was fabricated, and samples were harvested for material properties testing at both room and elevated temperatures. As a lower cost and lighter weight alternative to an all-rhenium component, rhenium- coated graphite and carbon-carbon were also evaluated. The rhenium-coated components were thermal-cycle tested to verify that they could withstand the expected thermal loads during service. High-temperature electroforming is based on electrochemical deposition of compact layers of metals onto a mandrel of the desired shape. Mandrels used for electro-deposition of near-net shaped parts are generally fabricated from high-density graphite. The graphite mandrel is easily machined and does not react with the molten electrolyte. For near-net shape components, the inner surface of the electroformed part replicates the polished graphite mandrel. During processing, the mandrel itself becomes the cathode, and scrap or refined refractory metal is the anode. Refractory metal atoms from the anode material are ionized in the molten electrolytic solution, and are deposited onto the cathodic mandrel by electrochemical reduction. Rotation of the mandrel ensures uniform distribution of refractory material. The EL-Form process allows for manufacturing in an inert atmosphere with deposition rates from 0.0004 to 0.002 in./h (10.2 to 50.8 m/h). Thicknesses typically range from microns to greater than 0.5 in. (13 mm). The refractory component produced is fabricated, dependably, to within one micron of the desired tolerances with no shrinkage or distortion as in other refractory metal manufacture techniques. The electroforming process has been used to produce solid, nonporous deposits of rhenium, iridium, niobium, tungsten, and their alloys.

  5. Development of nanomaterial-enabled advanced oxidation techniques for treatment of organic micropollutants

    NASA Astrophysics Data System (ADS)

    Oulton, Rebekah Lynn

    Increasing demand for limited fresh water resources necessitates that alternative water sources be developed. Nonpotable reuse of treated wastewater represents one such alternative. However, the ubiquitous presence of organic micropollutants such as pharmaceuticals and personal care products (PPCPs) in wastewater effluents limits use of this resource. Numerous investigations have examined PPCP fate during wastewater treatment, focusing on their removal during conventional and advanced treatment processes. Analysis of influent and effluent data from published studies reveals that at best 1-log10 concentration unit of PPCP removal can generally be achieved with conventional treatment. In contrast, plants employing advanced treatment methods, particularly ozonation and/or membranes, remove most PPCPs often to levels below analytical detection limits. However, membrane treatment is cost prohibitive for many facilities, and ozone treatment can be very selective. Ozone-recalcitrant compounds require the use of Advanced Oxidation Processes (AOPs), which utilize highly reactive hydroxyl radicals (*OH) to target resistant pollutants. Due to cost and energy use concerns associated with current AOPs, alternatives such as catalytic ozonation are under investigation. Catalytic ozonation uses substrates such as activated carbon to promote *OH formation during ozonation. Here, we show that multi-walled carbon nanotubes (MWCNTs) represent another viable substrate, promoting *OH formation during ozonation to levels exceeding activated carbon and equivalent to conventional ozone-based AOPs. Via a series of batch reactions, we observ a strong correlation between *OH formation and MWCNT surface oxygen concentrations. Results suggest that deprotonated carboxyl groups on the CNT surface are integral to their reactivity toward ozone and corresponding *OH formation. From a practical standpoint, we show that industrial grade MWCNTs exhibit similar *OH production as their research-grade counterparts. Accelerated aging studies indicate that MWCNTs maintain surface reactivity for an extended period during ozonation treatment. Further, *OH generation is essentially unaffected in complex water matrices containing known radical scavengers, and is effective for degradation of the ozone-recalcitrant herbicide atrazine. A proof-of-concept study verified that results from batch systems can be replicated in a flow-through reactor utilizing MWCNTs immobilized on a ceramic membrane support. Collective, results suggest that CNT-enhanced ozonation may provide a viable treatment alternative for emerging organic micropollutants.

  6. POC-SCALE TESTING OF AN ADVANCED FINE COAL DEWATERING EQUIPMENT/TECHNIQUE

    SciTech Connect

    B.K. PAREKH; D. TAO; J.G. GROPPO

    1998-02-03

    The main objective of the proposed program is to evaluate a novel surface modification technique, which utilizes the synergistic effect of metal ions-surfactant combination, for dewatering of ultra-fine clean coal on a proof-of-concept scale of 1 to 2 tph. The novel surface modification technique developed at the UKCAER will be evaluated using vacuum, centrifuge, and hyperbaric filtration equipment. Dewatering tests will be conducted using the fine clean-coal froth produced by the column flotation units at the Powell Mountain Coal Company, Mayflower Preparation Plant in St. Charles, Virginia. The POC-scale studies will be conducted on two different types of clean coal, namely, high-sulfur and low-sulfur clean coal. The Mayflower Plant processes coals from five different seams, thus the dewatering studies results could be generalized for most of the bituminous coals.

  7. Characterization of failure modes in deep UV and deep green LEDs utilizing advanced semiconductor localization techniques.

    SciTech Connect

    Tangyunyong, Paiboon; Miller, Mary A.; Cole, Edward Isaac, Jr.

    2012-03-01

    We present the results of a two-year early career LDRD that focused on defect localization in deep green and deep ultraviolet (UV) light-emitting diodes (LEDs). We describe the laser-based techniques (TIVA/LIVA) used to localize the defects and interpret data acquired. We also describe a defect screening method based on a quick electrical measurement to determine whether defects should be present in the LEDs. We then describe the stress conditions that caused the devices to fail and how the TIVA/LIVA techniques were used to monitor the defect signals as the devices degraded and failed. We also describe the correlation between the initial defects and final degraded or failed state of the devices. Finally we show characterization results of the devices in the failed conditions and present preliminary theories as to why the devices failed for both the InGaN (green) and AlGaN (UV) LEDs.

  8. Advances on molecular mechanism of the adaptive evolution of Chiroptera (bats).

    PubMed

    Yunpeng, Liang; Li, Yu

    2015-01-01

    As the second biggest animal group in mammals, Chiroptera (bats) demonstrates many unique adaptive features in terms of flight, echolocation, auditory acuity, feeding habit, hibernation and immune defense, providing an excellent system for understanding the molecular basis of how organisms adapt to the living environments encountered. In this review, we summarize the researches on the molecular mechanism of the adaptive evolution of Chiroptera, especially the recent researches at the genome levels, suggesting a far more complex evolutionary pattern and functional diversity than previously thought. In the future, along with the increasing numbers of Chiroptera species genomes available, new evolutionary patterns and functional divergence will be revealed, which can promote the further understanding of this animal group and the molecular mechanism of adaptive evolution. PMID:25608810

  9. Recent Advances in Genetic Technique of Microbial Report Cells and Their Applications in Cell Arrays

    PubMed Central

    Kim, Do Hyun; Kim, Moon Il; Park, Hyun Gyu

    2015-01-01

    Microbial cell arrays have attracted consistent attention for their ability to provide unique global data on target analytes at low cost, their capacity for readily detectable and robust cell growth in diverse environments, their high degree of convenience, and their capacity for multiplexing via incorporation of molecularly tailored reporter cells. To highlight recent progress in the field of microbial cell arrays, this review discusses research on genetic engineering of reporter cells, technologies for patterning live cells on solid surfaces, cellular immobilization in different polymers, and studies on their application in environmental monitoring, disease diagnostics, and other related fields. On the basis of these results, we discuss current challenges and future prospects for novel microbial cell arrays, which show promise for use as potent tools for unraveling complex biological processes. PMID:26436087

  10. Application of Advanced Process Control techniques to a pusher type reheating furnace

    NASA Astrophysics Data System (ADS)

    Zanoli, S. M.; Pepe, C.; Barboni, L.

    2015-11-01

    In this paper an Advanced Process Control system aimed at controlling and optimizing a pusher type reheating furnace located in an Italian steel plant is proposed. The designed controller replaced the previous control system, based on PID controllers manually conducted by process operators. A two-layer Model Predictive Control architecture has been adopted that, exploiting a chemical, physical and economic modelling of the process, overcomes the limitations of plant operators’ mental model and knowledge. In addition, an ad hoc decoupling strategy has been implemented, allowing the selection of the manipulated variables to be used for the control of each single process variable. Finally, in order to improve the system flexibility and resilience, the controller has been equipped with a supervision module. A profitable trade-off between conflicting specifications, e.g. safety, quality and production constraints, energy saving and pollution impact, has been guaranteed. Simulation tests and real plant results demonstrated the soundness and the reliability of the proposed system.

  11. Advances in head and neck fine-needle aspiration and ultrasound technique for the pathologist.

    PubMed

    Jakowski, Joseph D; DiNardo, Laurence J

    2015-07-01

    The success of fine-needle aspiration (FNA) biopsy in the evaluation of head and neck (H&N) masses has already been established. Herein we outline the most recent advancement for the pathologist who performs traditional palpation-guided FNA (PGFNA) in the H&N while also incorporating ultrasound-guided FNA (UGFNA) into their practice. We provide an overview of the educational and training opportunities in H&N ultrasound and UGFNA with emphasis on the advantages and limitations for the pathologist. Throughout are useful clinical and technical pearls, many of which may also interest those who practice PGFNA, including local anesthesia use and FNA procedures in pediatric patients. PMID:25677264

  12. Advanced Fluid--Structure Interaction Techniques in Application to Horizontal and Vertical Axis Wind Turbines

    NASA Astrophysics Data System (ADS)

    Korobenko, Artem

    During the last several decades engineers and scientists put significant effort into developing reliable and efficient wind turbines. As a wind power production demands grow, the wind energy research and development need to be enhanced with high-precision methods and tools. These include time-dependent, full-scale, complex-geometry advanced computational simulations at large-scale. Those, computational analysis of wind turbines, including fluid-structure interaction simulations (FSI) at full scale is important for accurate and reliable modeling, as well as blade failure prediction and design optimization. In current dissertation the FSI framework is applied to most challenging class of problems, such as large scale horizontal axis wind turbines and vertical axis wind turbines. The governing equations for aerodynamics and structural mechanics together with coupled formulation are explained in details. The simulations are performed for different wind turbine designs, operational conditions and validated against field-test and wind tunnel experimental data.

  13. Advanced data visualization and sensor fusion: Conversion of techniques from medical imaging to Earth science

    NASA Technical Reports Server (NTRS)

    Savage, Richard C.; Chen, Chin-Tu; Pelizzari, Charles; Ramanathan, Veerabhadran

    1993-01-01

    Hughes Aircraft Company and the University of Chicago propose to transfer existing medical imaging registration algorithms to the area of multi-sensor data fusion. The University of Chicago's algorithms have been successfully demonstrated to provide pixel by pixel comparison capability for medical sensors with different characteristics. The research will attempt to fuse GOES (Geostationary Operational Environmental Satellite), AVHRR (Advanced Very High Resolution Radiometer), and SSM/I (Special Sensor Microwave Imager) sensor data which will benefit a wide range of researchers. The algorithms will utilize data visualization and algorithm development tools created by Hughes in its EOSDIS (Earth Observation SystemData/Information System) prototyping. This will maximize the work on the fusion algorithms since support software (e.g. input/output routines) will already exist. The research will produce a portable software library with documentation for use by other researchers.

  14. Advanced space power requirements and techniques. Task 1: Mission projections and requirements. Volume 1: Technical report

    NASA Technical Reports Server (NTRS)

    Wolfe, M. G.

    1978-01-01

    The objectives of this study were to: (1) develop projections of the NASA, DoD, and civil space power requirements for the 1980-1995 time period; (2) identify specific areas of application and space power subsystem type needs for each prospective user; (3) document the supporting and historical base, including relevant cost related measures of performance; and (4) quantify the benefits of specific technology projection advancements. The initial scope of the study included: (1) construction of likely models for NASA, DoD, and civil space systems; (2) generation of a number of future scenarios; (3) extraction of time phased technology requirements based on the scenarios; and (4) cost/benefit analyses of some of the technologies identified.

  15. Cross-band relative absorption technique for the measurement of molecular mixing ratios.

    PubMed

    Prasad, Narasimha S; Pliutau, Denis

    2013-06-01

    We describe a new method for the measurement of molecular mixing ratios called Cross-Band Relative Absorption (CoBRA). The proposed method is based on relative measurements in different molecular bands referenced to a band of O2 with properly selected wavelength combinations providing high level of cancelation in temperature sensitivities. The CoBRA approach is particularly promising for satellite based remote sensing of molecular mixing ratios of the atmospheric trace gases. Very low temperature sensitivities and the potential of achieving close weighting function matching for the measurement and reference wavelengths are the main advantages of the method. The effectiveness of CoBRA approach is demonstrated for the retrieval of CO2 mixing ratios (XCO2) with application to the ASCENDS mission. PMID:23736581

  16. Molecular diagnosis of soft tissue neoplasia: clinical applications and recent advances.

    PubMed

    Hameed, Meera

    2014-11-01

    Sarcomas are rare and heterogeneous neoplasms of mesenchymal tissues with diverse morphologies and clinical behavior. In the last few years, the discovery of specific genetic aberrations in these tumors has allowed better classification and understanding of mechanisms driving their pathogenesis. While the majority of sarcomas are still treated by traditional modalities, molecular markers driving the pathogenesis have paved the way for more accurate diagnosis and opportunity to explore other therapeutic strategies. This review discusses the available molecular tools in sarcoma diagnostics and highlight some of the biological significance of the recent discoveries and their clinical applications. PMID:25109831

  17. Integration of Advanced Probabilistic Analysis Techniques with Multi-Physics Models

    SciTech Connect

    Cetiner, Mustafa Sacit; none,; Flanagan, George F.; Poore III, Willis P.; Muhlheim, Michael David

    2014-07-30

    An integrated simulation platform that couples probabilistic analysis-based tools with model-based simulation tools can provide valuable insights for reactive and proactive responses to plant operating conditions. The objective of this work is to demonstrate the benefits of a partial implementation of the Small Modular Reactor (SMR) Probabilistic Risk Assessment (PRA) Detailed Framework Specification through the coupling of advanced PRA capabilities and accurate multi-physics plant models. Coupling a probabilistic model with a multi-physics model will aid in design, operations, and safety by providing a more accurate understanding of plant behavior. This represents the first attempt at actually integrating these two types of analyses for a control system used for operations, on a faster than real-time basis. This report documents the development of the basic communication capability to exchange data with the probabilistic model using Reliability Workbench (RWB) and the multi-physics model using Dymola. The communication pathways from injecting a fault (i.e., failing a component) to the probabilistic and multi-physics models were successfully completed. This first version was tested with prototypic models represented in both RWB and Modelica. First, a simple event tree/fault tree (ET/FT) model was created to develop the software code to implement the communication capabilities between the dynamic-link library (dll) and RWB. A program, written in C#, successfully communicates faults to the probabilistic model through the dll. A systems model of the Advanced Liquid-Metal Reactor–Power Reactor Inherently Safe Module (ALMR-PRISM) design developed under another DOE project was upgraded using Dymola to include proper interfaces to allow data exchange with the control application (ConApp). A program, written in C+, successfully communicates faults to the multi-physics model. The results of the example simulation were successfully plotted.

  18. Advanced sensing and control techniques to facilitate semi-autonomous decommissioning. 1998 annual progress report

    SciTech Connect

    Schalkoff, R.J.; Geist, R.M.; Dawson, D.M.

    1998-06-01

    'This research is intended to advance the technology of semi-autonomous teleoperated robotics as applied to Decontamination and Decommissioning (D and D) tasks. Specifically, research leading to a prototype dual-manipulator mobile work cell is underway. This cell is supported and enhanced by computer vision, virtual reality and advanced robotics technology. This report summarizes work after approximately 1.5 years of a 3-year project. The autonomous, non-contact creation of a virtual environment from an existing, real environment (virtualization) is an integral part of the workcell functionality. This requires that the virtual world be geometrically correct. To this end, the authors have encountered severe sensitivity in quadric estimation. As a result, alternative procedures for geometric rendering, iterative correction approaches, new calibration methods and associated hardware, and calibration quality examination software have been developed. Following geometric rendering, the authors have focused on improving the color and texture recognition components of the system. In particular, the authors have moved beyond first-order illumination modeling to include higher order diffuse effects. This allows us to combine the surface geometric information, obtained from the laser projection and surface recognition components of the system, with a stereo camera image. Low-level controllers for Puma 560 robotic arms were designed and implemented using QNX. The resulting QNX/PC based low-level robot control system is called QRobot. A high-level trajectory generator and application programming interface (API) as well as a new, flexible robot control API was required. Force/torque sensors and interface hardware have been identified and ordered. A simple 3-D OpenGL-based graphical Puma 560 robot simulator was developed and interfaced with ARCL and RCCL to assist in the development of robot motion programs.'

  19. Eigensolution techniques, their applications and Fisher?s information entropy of the Tietz-Wei diatomic molecular model

    NASA Astrophysics Data System (ADS)

    Falaye, B. J.; Oyewumi, K. J.; Ikhdair, S. M.; Hamzavi, M.

    2014-11-01

    In this study, the approximate analytical solutions of Schrödinger, Klein-Gordon and Dirac equations under the Tietz-Wei (TW) diatomic molecular potential are represented by using an approximation for the centrifugal term. We have applied three types of eigensolution techniques: the functional analysis approach, supersymmetry quantum mechanics and the asymptotic iteration method to solve the Klein-Gordon, Dirac and Schrödinger equations, respectively. The energy eigenvalues and the corresponding eigenfunctions for these three wave equations are obtained, and some numerical results and figures are reported. It has been shown that these techniques yielded exactly the same results. some expectation values of the TW diatomic molecular potential within the framework of the Hellmann-Feynman theorem have been presented. The probability distributions that characterize the quantum mechanical states of TW diatomic molecular potential are analyzed by means of complementary information measures of a probability distribution called Fisher's information entropy. This distribution has been described in terms of Jacobi polynomials, whose characteristics are controlled by quantum numbers.

  20. Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy: An analytical technique to understand therapeutic responses at the molecular level

    PubMed Central

    Kalmodia, Sushma; Parameswaran, Sowmya; Yang, Wenrong; Barrow, Colin J.; Krishnakumar, Subramanian

    2015-01-01

    Rapid monitoring of the response to treatment in cancer patients is essential to predict the outcome of the therapeutic regimen early in the course of the treatment. The conventional methods are laborious, time-consuming, subjective and lack the ability to study different biomolecules and their interactions, simultaneously. Since; mechanisms of cancer and its response to therapy is dependent on molecular interactions and not on single biomolecules, an assay capable of studying molecular interactions as a whole, is preferred. Fourier Transform Infrared (FTIR) spectroscopy has become a popular technique in the field of cancer therapy with an ability to elucidate molecular interactions. The aim of this study, was to explore the utility of the FTIR technique along with multivariate analysis to understand whether the method has the resolution to identify the differences in the mechanism of therapeutic response. Towards achieving the aim, we utilized the mouse xenograft model of retinoblastoma and nanoparticle mediated targeted therapy. The results indicate that the mechanism underlying the response differed between the treated and untreated group which can be elucidated by unique spectral signatures generated by each group. The study establishes the efficiency of non-invasive, label-free and rapid FTIR method in assessing the interactions of nanoparticles with cellular macromolecules towards monitoring the response to cancer therapeutics. PMID:26568521

  1. Testing the Cambrian explosion hypothesis by using a molecular dating technique.

    PubMed

    Bromham, L; Rambaut, A; Fortey, R; Cooper, A; Penny, D

    1998-10-13

    Molecular studies have the potential to shed light on the origin of the animal phyla by providing independent estimates of the divergence times, but have been criticized for failing to account adequately for variation in rate of evolution. A method of dating divergence times from molecular data addresses the criticisms of earlier studies and provides more realistic, but wider, confidence intervals. The data are not compatible with the Cambrian explosion hypothesis as an explanation for the origin of metazoan phyla, and provide additional support for an extended period of Precambrian metazoan diversification. PMID:9770496

  2. Multispectral indices and advanced classification techniques to detect percent residue cover over agricultural crops using Landsat data

    NASA Astrophysics Data System (ADS)

    Pacheco, Anna; McNairn, Heather; Smith, Anne M.

    2006-08-01

    Detecting and quantifying crop residue cover on agricultural fields is essential in identifying conservation tillage practices and estimating carbon sequestration, both of which are important goals within the Agricultural Policy Framework of Agriculture and Agri-Food Canada. Crop residue is traditionally measured using ground survey techniques such as the line-transect method or visual (drive-by) assessment but these techniques are tedious, time-consuming and subjective. With the increased number of advanced earth observation satellites, remote sensing has now become a viable option for mapping agricultural land management practices and percent crop residue cover. A wide variety of indices such as the Normalized Difference Index (NDI) and the Modified Soil Adjusted Crop Residue Index (MSACRI) were developed using multispectral data for this purpose but results have been mixed. Advanced classification techniques including linear spectral mixture analysis (SMA) and spectral angle mapper (SAM) provide an alternative to derive percent crop residue cover. Landsat-7 SLC-Off data were acquired over an agricultural study site in Eastern Ontario on May 25 2005. Simultaneous ground data were collected to characterize residue type, position, direction and percent cover. NDI, MSACRI, SMA and SAM were all computed and used to derive percent crop residue cover information. Preliminary results indicate that the SMA model predicts percent crop residue cover over agricultural fields with the most success, especially over fields of corn residue with an R2 value of 0.85 (RMSE of 12.46 and D of 0.99). However, further investigation is needed where residue models are validated against a larger dataset with greater variability in percent crop residue cover.

  3. March 1998 361MOLECULAR TECHNIQUES IN ECOLOGY Ecology, 79(2), 1998, pp. 361382

    E-print Network

    Snow, Allison A.

    for most taxa, although techniques based on nucleic acids (par- ticularly DNA sequencing and mitochondrial's application, and (3) the pragmatics of time and costs of materials. Here we evaluate the application of several major techniques (protein electrophoresis, nuclear and mitochondrial RFLPs [restriction fragment

  4. Technological Advances in Bifidobacterial Molecular Genetics: Application to Functional Genomics and Medical Treatments

    PubMed Central

    FUKIYA, Satoru; HIRAYAMA, Yosuke; SAKANAKA, Mikiyasu; KANO, Yasunobu; YOKOTA, Atsushi

    2012-01-01

    Bifidobacteria are well known as beneficial intestinal bacteria that exert health-promoting effects in humans. In addition to physiological and immunological investigations, molecular genetic technologies have been developed and have recently started to be applied to clarify the molecular bases of host-Bifidobacterium interactions. These technologies include transformation technologies and Escherichia coli-Bifidobacterium shuttle vectors that enable heterologous gene expression. In this context, a plasmid artificial modification method that protects the introduced plasmid from the restriction system in host bifidobacteria has recently been developed to increase transformation efficiency. On the other hand, targeted gene inactivation systems, which are vital for functional genomics, seemed far from being practically applicable in bifidobacteria. However, remarkable progress in this technology has recently been achieved, enabling functional genomics in bifidobacteria. Integrated use of these molecular genetic technologies with omics-based analyses will surely boost characterization of the molecular basis underlying beneficial effects of bifidobacteria. Applications of recombinant bifidobacteria to medical treatments have also progressed. PMID:24936345

  5. 78 FR 59927 - Next Generation Risk Assessment: Incorporation of Recent Advances in Molecular, Computational...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-30

    ... Systems Biology [External Review Draft] AGENCY: Environmental Protection Agency (EPA). ACTION: Notice of... Molecular, Computational, and Systems Biology '' (EPA/600/R-13/214A). EPA is also announcing that Eastern..., Computational, and Systems Biology '' is available primarily via the Internet on the NCEA home page under...

  6. Upfront molecular testing in patients with advanced gastro-esophageal cancer: Is it time yet?

    PubMed Central

    Mikhail, Sameh; Ciombor, Kristen; Noonan, Anne; Wu, Christina; Goldberg, Richard; Zhao, Weiqiang; Wei, Lai; Mathey, Kristina; Yereb, Melissa; Timmers, Cynthia; Bekaii-Saab, Tanios

    2015-01-01

    Introduction Targeting HER2 has improved outcomes in metastatic GE (mGE) cancer. In this study, we aim to explore the feasibility of molecular profiling in patients with refractory mGE cancer in routine clinical practice. Methods Archival formalin-fixed, paraffin-embedded (FFPE) samples for patients with mGE were analyzed with commercially available targeted next generation sequencing (NGS) and/or FISH for MET amplification. We also reviewed the patients' medical records for concurrent HER 2 testing. Results Tumor samples from 99 patients with mGE cancer were analyzed as follows: NGS (N = 56), FISH for MET amplification (N = 65), IHC and/or FISH for HER2 (N = 87). Of patients who underwent NGS, 50/56 (89%) had at least one actionable molecular alteration. The most notable actionable alterations included cell cycle abnormalities (58%), HER2 amplification (30%), PI3KCA mutation (14%), MCL1 amplification (11%), PTEN loss (9%), CDH1 mutation (2%) and MET amplification (5%). Ninety-two percent (12/13) of patients with HER2 amplification by NGS were positive for HER2 by IHC and/or FISH. In contrast, only 12/18 (66%) patients positive for HER2 by IHC and/or FISH demonstrated HER2 amplification by NGS. Conclusion Comprehensive molecular testing is feasible in clinical practice and provides a platform for screening patients for molecularly guided clinical trials and available targeted therapies. PMID:26082439

  7. Research Advances: Nanoscale Molecular Tweezers; Cinnamon as Pesticide?; Recently Identified Dietary Sources of Antioxidants

    NASA Astrophysics Data System (ADS)

    King, Angela G.

    2004-12-01

    This Report from Other Journals surveys articles of interest to chemists that have been recently published in other science journals. Topics surveyed include reports that receptors have been designed to act as molecular tweezers; cinnamon has potential in the fight against mosquitoes; and high levels of antioxidants are found in some surprising foods. See Featured Molecules .

  8. Introduction of soft X-ray spectromicroscopy as an advanced technique for plant biopolymers research.

    PubMed

    Karunakaran, Chithra; Christensen, Colleen R; Gaillard, Cedric; Lahlali, Rachid; Blair, Lisa M; Perumal, Vijayan; Miller, Shea S; Hitchcock, Adam P

    2015-01-01

    Soft X-ray absorption spectroscopy coupled with nano-scale microscopy has been widely used in material science, environmental science, and physical sciences. In this work, the advantages of soft X-ray absorption spectromicroscopy for plant biopolymer research were demonstrated by determining the chemical sensitivity of the technique to identify common plant biopolymers and to map the distributions of biopolymers in plant samples. The chemical sensitivity of soft X-ray spectroscopy to study biopolymers was determined by recording the spectra of common plant biopolymers using soft X-ray and Fourier Transform mid Infrared (FT-IR) spectroscopy techniques. The soft X-ray spectra of lignin, cellulose, and polygalacturonic acid have distinct spectral features. However, there were no distinct differences between cellulose and hemicellulose spectra. Mid infrared spectra of all biopolymers were unique and there were differences between the spectra of water soluble and insoluble xylans. The advantage of nano-scale spatial resolution exploited using soft X-ray spectromicroscopy for plant biopolymer research was demonstrated by mapping plant cell wall biopolymers in a lentil stem section and compared with the FT-IR spectromicroscopy data from the same sample. The soft X-ray spectromicroscopy enables mapping of biopolymers at the sub-cellular (~30 nm) resolution whereas, the limited spatial resolution in the micron scale range in the FT-IR spectromicroscopy made it difficult to identify the localized distribution of biopolymers. The advantages and limitations of soft X-ray and FT-IR spectromicroscopy techniques for biopolymer research are also discussed. PMID:25811457

  9. Introduction of Soft X-Ray Spectromicroscopy as an Advanced Technique for Plant Biopolymers Research

    PubMed Central

    Karunakaran, Chithra; Christensen, Colleen R.; Gaillard, Cedric; Lahlali, Rachid; Blair, Lisa M.; Perumal, Vijayan; Miller, Shea S.; Hitchcock, Adam P.

    2015-01-01

    Soft X-ray absorption spectroscopy coupled with nano-scale microscopy has been widely used in material science, environmental science, and physical sciences. In this work, the advantages of soft X-ray absorption spectromicroscopy for plant biopolymer research were demonstrated by determining the chemical sensitivity of the technique to identify common plant biopolymers and to map the distributions of biopolymers in plant samples. The chemical sensitivity of soft X-ray spectroscopy to study biopolymers was determined by recording the spectra of common plant biopolymers using soft X-ray and Fourier Transform mid Infrared (FT-IR) spectroscopy techniques. The soft X-ray spectra of lignin, cellulose, and polygalacturonic acid have distinct spectral features. However, there were no distinct differences between cellulose and hemicellulose spectra. Mid infrared spectra of all biopolymers were unique and there were differences between the spectra of water soluble and insoluble xylans. The advantage of nano-scale spatial resolution exploited using soft X-ray spectromicroscopy for plant biopolymer research was demonstrated by mapping plant cell wall biopolymers in a lentil stem section and compared with the FT-IR spectromicroscopy data from the same sample. The soft X-ray spectromicroscopy enables mapping of biopolymers at the sub-cellular (~30 nm) resolution whereas, the limited spatial resolution in the micron scale range in the FT-IR spectromicroscopy made it difficult to identify the localized distribution of biopolymers. The advantages and limitations of soft X-ray and FT-IR spectromicroscopy techniques for biopolymer research are also discussed. PMID:25811457

  10. Advanced definition study for the determination of atmospheric ozone using the satellite eclipse technique

    NASA Technical Reports Server (NTRS)

    Emmons, R.; Preski, R. J.; Kierstead, F. H., Jr.; Doll, F. C.; Wight, D. T.; Romick, D. C.

    1973-01-01

    A study was made to evaluate the potential for remote ground-based measurement of upper atmospheric ozone by determining the absorption ratio of selected narrow bands of sunlight as reflected by satellites while passing into eclipse, using the NASA Mobile Satellite Photometric Observatory (MOSPO). Equipment modifications to provide optimum performance were analyzed and recommendations were made for improvements to the system to accomplish this. These included new sensor tubes, pulse counting detection circuitry, filters, beam splitters and associated optical revision, along with an automatic tracking capability plus corresponding operational techniques which should extend the overall measurement capability to include use of satellites down to 5th magnitude.

  11. Advanced Technologies for the Improvement of Spray Application Techniques in Spanish Viticulture: An Overview

    PubMed Central

    Gil, Emilio; Arnó, Jaume; Llorens, Jordi; Sanz, Ricardo; Llop, Jordi; Rosell-Polo, Joan R.; Gallart, Montserrat; Escolà, Alexandre

    2014-01-01

    Spraying techniques have been undergoing continuous evolution in recent decades. This paper presents part of the research work carried out in Spain in the field of sensors for characterizing vineyard canopies and monitoring spray drift in order to improve vineyard spraying and make it more sustainable. Some methods and geostatistical procedures for mapping vineyard parameters are proposed, and the development of a variable rate sprayer is described. All these technologies are interesting in terms of adjusting the amount of pesticides applied to the target canopy. PMID:24451462

  12. Development of techniques for advanced optical contamination measurement with internal reflection spectroscopy, phase 1, volume 1

    NASA Technical Reports Server (NTRS)

    Hayes, J. D.

    1972-01-01

    The feasibility of monitoring volatile contaminants in a large space simulation chamber using techniques of internal reflection spectroscopy was demonstrated analytically and experimentally. The infrared spectral region was selected as the operational spectral range in order to provide unique identification of the contaminants along with sufficient sensitivity to detect trace contaminant concentrations. It was determined theoretically that a monolayer of the contaminants could be detected and identified using optimized experimental procedures. This ability was verified experimentally. Procedures were developed to correct the attenuated total reflectance spectra for thick sample distortion. However, by using two different element designs the need for such correction can be avoided.

  13. Advanced Failure Determination Measurement Techniques Used in Thermal Fatigue Life Testing of Electronic Packaging

    NASA Technical Reports Server (NTRS)

    Wallace, A. P.; Cornford, S. L.; Gross, M. A.

    1996-01-01

    Thermal fatigue life testing of various electronic packaging technologies is being performed by the Reliability Technology Group at the Jet Propulsion Laboratory. These testing efforts are in progress to improve uderstanding of the reliability issues associated with low volume packaging technologies for space applications and to develop qualification and acceptance approaches for these technologies. The work described here outlines the electrical failure detection techniques used during testing by documenting the circuits and components used to make these measurements, the sensitivity of the measurements, and the applicability of each specific measurement.

  14. Next Generation Risk Assessment: Incorporation of Recent Advances in Molecular, Computational, and Systems Biology (Final Report)

    EPA Science Inventory

    Cover of the Next Generation of Risk Assessment Final report This final report, "Next Generation Risk Assessment: Recent Advances in Molec...

  15. Screening strawberry (Fragria x ananassa) germplasm for anthracnose disease resistance using traditional techniques and molecular makers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anthracnose of strawberry may be caused by any of three Colletotrichum species: C. acutatum, C. gloeosporioides or C. fragariae. These destructive pathogens may infect the fruit, leaves, petioles, crowns or roots and may cause plant death. Traditional and molecular approaches were used to identify a...

  16. SCIENCE RESULTS INTEGRATION. BRINGING MOLECULAR BIOLOGY TECHNIQUES TO REGIONAL WATER MONITORING PROGRAMS

    EPA Science Inventory

    EPA's Office of Research and Development (ORD) develops innovative methods for use in environmental monitoring and assessment by scientists in Regions, states, and Tribes. Molecular-biology-based methods are not yet established in the environmental monitoring "tool box". SRI (Sci...

  17. Experimental investigations of micro-scale flow and heat transfer phenomena by using molecular tagging techniques

    E-print Network

    Hu, Hui

    and accretion processes as water droplets impinge onto cold wind turbine blades. Keywords: molecular tagging, China. 5 Present address: BD Medical, Franklin Lakes, NJ 07417, USA. 1. Introduction At present, the most commonly used tool for in situ imaging of microflows is the micro-particle imaging velocimetry

  18. Advanced combination of laser and synchrotron techniques to study minerals at extreme conditions in the time-domain mode (Invited)

    NASA Astrophysics Data System (ADS)

    Prakapenka, V.; Zinin, P.; Goncharov, A.; Zhuravlev, K. K.; Tkachev, S. N.

    2013-12-01

    Over the past two decades, high pressure research has made breakthrough progress in many fields of science mainly due to significant advances in development of both high pressure vessels (diamond anvil cell and large volume press) and high brilliance synchrotron based techniques, including high resolution x-ray micro-diffraction, x-ray spectroscopy (absorption, emission, resonance), micro-imaging, inelastic and nuclear resonance scattering. Combination of double-sided laser heating with synchrotron x-ray radiation has stimulated synthesis and investigation of new materials with unique composition and properties in-situ at high temperatures and high pressures in the diamond anvil cell. Equation of state, structure, phase transformations, element partitioning, electronic and optical properties of various minerals (single crystal, powder, nano-crystalline, amorphous solid and fluids) have been successfully studied at extreme conditions with help of the lasers and x-ray beams. Recent developments in pulse laser heating technique, including application of fiber lasers and flat top laser beam shaping optics, result in significant improvement in synthesis of new metastable materials with tuneable composition and properties controlled in-situ with high resolution x-ray and optical techniques in time-domain mode. To study elastic properties of opaque minerals in situ at high pressure and temperature we have combined laser ultrasonic with laser heating techniques. The shear and longitudinal wave velocities were measured for iron at pressures up to 60 GPa in the diamond anvil cell. The details and application of the synchrotron and optical techniques for studies unique physical and chemical properties of minerals in-situ at extreme conditions will be discussed on example of iron-bearing materials.

  19. Direct assignment of molecular vibrations via normal mode analysis of the neutron dynamic pair distribution function technique

    NASA Astrophysics Data System (ADS)

    Fry-Petit, A. M.; Rebola, A. F.; Mourigal, M.; Valentine, M.; Drichko, N.; Sheckelton, J. P.; Fennie, C. J.; McQueen, T. M.

    2015-09-01

    For over a century, vibrational spectroscopy has enhanced the study of materials. Yet, assignment of particular molecular motions to vibrational excitations has relied on indirect methods. Here, we demonstrate that applying group theoretical methods to the dynamic pair distribution function analysis of neutron scattering data provides direct access to the individual atomic displacements responsible for these excitations. Applied to the molecule-based frustrated magnet with a potential magnetic valence-bond state, LiZn2Mo3O8, this approach allows direct assignment of the constrained rotational mode of Mo3O13 clusters and internal modes of MoO6 polyhedra. We anticipate that coupling this well known data analysis technique with dynamic pair distribution function analysis will have broad application in connecting structural dynamics to physical properties in a wide range of molecular and solid state systems.

  20. Molecular Techniques for the Detection and Differentiation of Host and Parasitoid Species and the Implications for Fruit Fly Management

    PubMed Central

    Jenkins, Cheryl; Chapman, Toni A.; Micallef, Jessica L.; Reynolds, Olivia L.

    2012-01-01

    Parasitoid detection and identification is a necessary step in the development and implementation of fruit fly biological control strategies employing parasitoid augmentive release. In recent years, DNA-based methods have been used to identify natural enemies of pest species where morphological differentiation is problematic. Molecular techniques also offer a considerable advantage over traditional morphological methods of fruit fly and parasitoid discrimination as well as within-host parasitoid identification, which currently relies on dissection of immature parasitoids from the host, or lengthy and labour-intensive rearing methods. Here we review recent research focusing on the use of molecular strategies for fruit fly and parasitoid detection and differentiation and discuss the implications of these studies on fruit fly management. PMID:26466628

  1. Direct assignment of molecular vibrations via normal mode analysis of the neutron dynamic pair distribution function technique.

    PubMed

    Fry-Petit, A M; Rebola, A F; Mourigal, M; Valentine, M; Drichko, N; Sheckelton, J P; Fennie, C J; McQueen, T M

    2015-09-28

    For over a century, vibrational spectroscopy has enhanced the study of materials. Yet, assignment of particular molecular motions to vibrational excitations has relied on indirect methods. Here, we demonstrate that applying group theoretical methods to the dynamic pair distribution function analysis of neutron scattering data provides direct access to the individual atomic displacements responsible for these excitations. Applied to the molecule-based frustrated magnet with a potential magnetic valence-bond state, LiZn2Mo3O8, this approach allows direct assignment of the constrained rotational mode of Mo3O13 clusters and internal modes of MoO6 polyhedra. We anticipate that coupling this well known data analysis technique with dynamic pair distribution function analysis will have broad application in connecting structural dynamics to physical properties in a wide range of molecular and solid state systems. PMID:26429001

  2. Study on the interaction of the epilepsy drug, zonisamide with human serum albumin (HSA) by spectroscopic and molecular docking techniques

    NASA Astrophysics Data System (ADS)

    Shahabadi, Nahid; Khorshidi, Aref; Moghadam, Neda Hossinpour

    2013-10-01

    In the present investigation, an attempt has been made to study the interaction of zonisamide (ZNS) with the transport protein, human serum albumin (HSA) employing UV-Vis, fluorometric, circular dichroism (CD) and molecular docking techniques. The results indicated that binding of ZNS to HSA caused strong fluorescence quenching of HSA through static quenching mechanism, hydrogen bonds and van der Waals contacts are the major forces in the stability of protein ZNS complex and the process of the binding of ZNS with HSA was driven by enthalpy (?H = -193.442 kJ mol-1). The results of CD and UV-Vis spectroscopy showed that the binding of this drug to HSA induced conformational changes in HSA. Furthermore, the study of molecular docking also indicated that zonisamide could strongly bind to the site I (subdomain IIA) of HSA mainly by hydrophobic interaction and there were hydrogen bond interactions between this drug and HSA, also known as the warfarin binding site.

  3. Advanced techniques for neoclassical tearing mode control in DIII-D

    SciTech Connect

    Volpe, F. A. G.; Austin, M. E.; La Haye, R. J.; Lohr, J.; Prater, R.; Strait, E. J.; Welander, A. S.

    2009-10-15

    Two techniques were developed at DIII-D [J. L. Luxon, Nucl. Fusion 42, 64 (2002)] to tackle ITER-specific aspects of neoclassical tearing mode (NTM) control, namely, (1) the relatively small size of the rotating islands, smaller than the electron cyclotron current drive (ECCD) deposition region, and (2) the increased tendency of the islands, compared to present devices, to lock to the wall or to the residual error field, in a position not necessarily accessible to ECCD. Modulated ECCD is known to suppress small islands more efficiently, when ''broad,'' than continuous ECCD. At DIII-D, a NTM of poloidal/toroidal mode numbers m/n=3/2 was completely stabilized by a new technique where oblique electron cyclotron emission acted at the same time as an indicator of good alignment between ECCD and the island, and as a waveform generator, for modulation in synch and in phase with the island O-point. In another experiment, after locking in an unfavorable position, a 2/1 island was steered by externally generated magnetic perturbations, brought in the view of the gyrotrons and partly stabilized by ECCD in the island O-point. Magnetic perturbations were also used to sustain and control the mode rotation, which has the potential for an easier ECCD modulation.

  4. Advanced numerical techniques for accurate unsteady simulations of a wingtip vortex

    NASA Astrophysics Data System (ADS)

    Ahmad, Shakeel

    A numerical technique is developed to simulate the vortices associated with stationary and flapping wings. The Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations are used over an unstructured grid. The present work assesses the locations of the origins of vortex generation, models those locations and develops a systematic mesh refinement strategy to simulate vortices more accurately using the URANS model. The vortex center plays a key role in the analysis of the simulation data. A novel approach to locating a vortex center is also developed referred to as the Max-Max criterion. Experimental validation of the simulated vortex from a stationary NACA0012 wing is achieved. The tangential velocity along the core of the vortex falls within five percent of the experimental data in the case of the stationary NACA0012 simulation. The wing surface pressure coefficient also matches with the experimental data. The refinement techniques are then focused on unsteady simulations of pitching and dual-mode wing flapping. Tip vortex strength, location, and wing surface pressure are analyzed. Links to vortex behavior and wing motion are inferred. Key words: vortex, tangential velocity, Cp, vortical flow, unsteady vortices, URANS, Max-Max, Vortex center

  5. Advanced radiation techniques for inspection of diesel engine combustion chamber materials components. Final report

    SciTech Connect

    1995-10-09

    Heavy duty truck engines must meet stringent life cycle cost and regulatory requirements. Meeting these requirements has resulted in convergence on 4-stroke 6-in-line, turbocharged, and after-cooled engines with direct-injection combustion systems. These engines provide much higher efficiencies (42%, fuel consumption 200 g/kW-hr) than automotive engines (31%, fuel consumption 270 g/kW-hr), but at higher initial cost. Significant near-term diesel engine improvements are necessary and are spurred by continuing competitive, Middle - East oil problems and Congressional legislation. As a result of these trends and pressures, Caterpillar has been actively pursuing a low-fuel consumption engine research program with emphasis on product quality through process control and product inspection. The goal of this project is to combine the nondestructive evaluation and computational resources and expertise available at LLNL with the diesel engine and manufacturing expertise of the Caterpillar Corporation to develop in-process monitoring and inspection techniques for diesel engine combustion chamber components and materials. Early development of these techniques will assure the optimization of the manufacturing process by design/inspection interface. The transition from the development stage to the manufacturing stage requires a both a thorough understanding of the processes and a way of verifying conformance to process standards. NDE is one of the essential tools in accomplishing both elements and in this project will be integrated with Caterpillar`s technological and manufacturing expertise to accomplish the project goals.

  6. A hybrid numerical technique for predicting the aerodynamic and acoustic fields of advanced turboprops

    NASA Technical Reports Server (NTRS)

    Homicz, G. F.; Moselle, J. R.

    1985-01-01

    A hybrid numerical procedure is presented for the prediction of the aerodynamic and acoustic performance of advanced turboprops. A hybrid scheme is proposed which in principle leads to a consistent simultaneous prediction of both fields. In the inner flow a finite difference method, the Approximate-Factorization Alternating-Direction-Implicit (ADI) scheme, is used to solve the nonlinear Euler equations. In the outer flow the linearized acoustic equations are solved via a Boundary-Integral Equation (BIE) method. The two solutions are iteratively matched across a fictitious interface in the flow so as to maintain continuity. At convergence the resulting aerodynamic load prediction will automatically satisfy the appropriate free-field boundary conditions at the edge of the finite difference grid, while the acoustic predictions will reflect the back-reaction of the radiated field on the magnitude of the loading source terms, as well as refractive effects in the inner flow. The equations and logic needed to match the two solutions are developed and the computer program implementing the procedure is described. Unfortunately, no converged solutions were obtained, due to unexpectedly large running times. The reasons for this are discussed and several means to alleviate the situation are suggested.

  7. QA procedures needed for advanced RT techniques and its impact on treatment outcome

    NASA Astrophysics Data System (ADS)

    Knöös, T.

    2015-01-01

    The radiotherapy process is reviewed briefly and potential risks or pitfalls are identified. The focus is on modern advanced modalities in radiation therapy such as IMRT, VMAT, gating and tracking and also for the unknown to come. Existing methods, or quality controls (QC), or with better word barriers, are introduced at important steps of process with the purpose of prohibiting errors to continue through the process and thus avoiding an unwanted erroneous irradiation of the patient. The soft branch of quality assurance (QA) such as peer-review is also a major component of today's process and its safety. The importance of knowing your QCs is pointed out. The role of dosimetry method i.e. 3D-dosimetry is reviewed. Staff have to be working with awareness and alertness that can reduce most of the risks. Having comprehensive protocols known by all involved together with well-trained staff at the department with dedicated functions and responsibilities will further reduce the risk for unintended irradiations of patient. Having a well-designed QA system with the appropriate barriers have the possibility of producing high quality radiotherapy, which will also result in better outcome for the patients. The international head and neck trial illustrates very well the importance of accurate radiotherapy.

  8. Advance of the upsetting technology theory and technique in a hydraulic press

    SciTech Connect

    Liu Zhubai; Wang Liandong; Liang Chen; Liu Guohui

    1996-12-31

    The tension stress theory of a rigid-plastic mechanical model when the ratio of height to diameter (HID) larger than 1 and the shearing stress theory if a hydrostatic stress mechanical model when HID less than 1 are advanced for the problem of upsetting a cylinder between common flat platens. The former breaks the saying described in traditional engineering plastic mechanics that there always exist three-dimensional compressive stresses in the interior of an upsetting body. The latter perfectly interprets the problem that there often present the flaws with meat pie in the heavy forgings. The new theory of flat platen upsetting has been testified by the qualitative physical simulation, the quantitative numerical simulation, the generalized slip-line solution, the mechanical slab method and the dissecting test in production. Two new mechanical model for upsetting a square body and the new technology and its mechanical principal of upsetting between the cone-shaped platens are further proposed on the basis of the new theory.

  9. Dynamic rain fade compensation techniques for the advanced communications technology satellite

    NASA Technical Reports Server (NTRS)

    Manning, Robert M.

    1992-01-01

    The dynamic and composite nature of propagation impairments that are incurred on earth-space communications links at frequencies in and above the 30/20 GHz Ka band necessitate the use of dynamic statistical identification and prediction processing of the fading signal in order to optimally estimate and predict the levels of each of the deleterious attenuation components. Such requirements are being met in NASA's Advanced Communications Technology Satellite (ACTS) project by the implementation of optimal processing schemes derived through the use of the ACTS Rain Attenuation Prediction Model and nonlinear Markov filtering theory. The ACTS Rain Attenuation Prediction Model discerns climatological variations on the order of 0.5 deg in latitude and longitude in the continental U.S. The time-dependent portion of the model gives precise availability predictions for the 'spot beam' links of ACTS. However, the structure of the dynamic portion of the model, which yields performance parameters such as fade duration probabilities, is isomorphic to the state-variable approach of stochastic control theory and is amenable to the design of such statistical fade processing schemes which can be made specific to the particular climatological location at which they are employed.

  10. Advanced passivation techniques for Si solar cells with high-? dielectric materials

    NASA Astrophysics Data System (ADS)

    Geng, Huijuan; Lin, Tingjui; Letha, Ayra Jagadhamma; Hwang, Huey-Liang; Kyznetsov, Fedor A.; Smirnova, Tamara P.; Saraev, Andrey A.; Kaichev, Vasily V.

    2014-09-01

    Electronic recombination losses at the wafer surface significantly reduce the efficiency of Si solar cells. Surface passivation using a suitable thin dielectric layer can minimize the recombination losses. Herein, advanced passivation using simple materials (Al2O3, HfO2) and their compounds H(Hf)A(Al)O deposited by atomic layer deposition (ALD) was investigated. The chemical composition of Hf and Al oxide films were determined by X-ray photoelectron spectroscopy (XPS). The XPS depth profiles exhibit continuous uniform dense layers. The ALD-Al2O3 film has been found to provide negative fixed charge (-6.4 × 1011 cm-2), whereas HfO2 film provides positive fixed charge (3.2 × 1012 cm-2). The effective lifetimes can be improved after oxygen gas annealing for 1 min. I-V characteristics of Si solar cells with high-? dielectric materials as passivation layers indicate that the performance is significantly improved, and ALD-HfO2 film would provide better passivation properties than that of the ALD-Al2O3 film in this research work.

  11. Advanced passivation techniques for Si solar cells with high-? dielectric materials

    SciTech Connect

    Geng, Huijuan; Hwang, Huey-Liang; Kyznetsov, Fedor A.; Smirnova, Tamara P.; Saraev, Andrey A.; Kaichev, Vasily V.

    2014-09-22

    Electronic recombination losses at the wafer surface significantly reduce the efficiency of Si solar cells. Surface passivation using a suitable thin dielectric layer can minimize the recombination losses. Herein, advanced passivation using simple materials (Al{sub 2}O{sub 3}, HfO{sub 2}) and their compounds H{sub (Hf)}A{sub (Al)}O deposited by atomic layer deposition (ALD) was investigated. The chemical composition of Hf and Al oxide films were determined by X-ray photoelectron spectroscopy (XPS). The XPS depth profiles exhibit continuous uniform dense layers. The ALD-Al{sub 2}O{sub 3} film has been found to provide negative fixed charge (?6.4?×?10{sup 11?}cm{sup ?2}), whereas HfO{sub 2} film provides positive fixed charge (3.2?×?10{sup 12?}cm{sup ?2}). The effective lifetimes can be improved after oxygen gas annealing for 1?min. I-V characteristics of Si solar cells with high-? dielectric materials as passivation layers indicate that the performance is significantly improved, and ALD-HfO{sub 2} film would provide better passivation properties than that of the ALD-Al{sub 2}O{sub 3} film in this research work.

  12. The advancement of a technique using principal component analysis for the non-intrusive depth profiling of radioactive contamination

    SciTech Connect

    Adams, J. C.; Joyce, M. J.; Mellor, M.

    2011-07-01

    A non-intrusive technique using principal component analysis, to infer the depth of the fission fragment caesium-137, when it is buried under silica sand has been described. Using energy variances within different {gamma}-ray spectra, a complete depth model was produced for a single caesium-137 source buried under 1 mm depths ranging between 5-50 mm. This was achieved using a cadmium telluride detector and a bespoke phantom. In this paper we describe the advancement of the technique by further validating it using blind tests for applications outside of the laboratory, where not only the depth (z) but also the surface (x, y) location of {gamma}-ray emitting contamination is often poorly characterised. At present the technique has been tested at the point of maximum activity above the entrained {gamma}-ray emitting source (where the optimal x, y location is known). This is not usually practical in poorly characterized environments where the detector cannot be conveniently placed at such an optimal location to begin with and scanning at multiple points around the region of interest is often required. Using a uniform scanning time, the point of maximum intensity can be located by sampling in terms of total count rate, and converging on this optimal point of maximum intensity. (authors)

  13. The Application of Advanced Cultivation Techniques in the Long Term Maintenance of Space Flight Plant Biological Systems

    NASA Technical Reports Server (NTRS)

    Heyenga, A. G.

    2003-01-01

    The development of the International Space Station (ISS) presents extensive opportunities for the implementation of long duration space life sciences studies. Continued attention has been placed in the development of plant growth chamber facilities capable of supporting the cultivation of plants in space flight microgravity conditions. The success of these facilities is largely dependent on their capacity to support the various growth requirements of test plant species. The cultivation requirements for higher plant species are generally complex, requiring specific levels of illumination, temperature, humidity, water, nutrients, and gas composition in order to achieve normal physiological growth and development. The supply of water, nutrients, and oxygen to the plant root system is a factor, which has proven to be particularly challenging in a microgravity space flight environment. The resolution of this issue is particularly important for the more intensive crop cultivation of plants envisaged in Nasa's advanced life support initiative. BioServe Space Technologies is a NASA, Research Partnership Center (RPC) at the University of Colorado, Boulder. BioServe has designed and operated various space flight plant habitat systems, and placed specific emphasis on the development and enhanced performance of subsystem components such as water and nutrient delivery, illumination, gas exchange and atmosphere control, temperature and humidity control. The further development and application of these subsystems to next generation habitats is of significant benefit and contribution towards the development of both the Space Plant biology and the Advanced Life Support Programs. The cooperative agreement between NASA Ames Research center and BioServe was established to support the further implementation of advanced cultivation techniques and protocols to plant habitat systems being coordinated at NASA Ames Research Center. Emphasis was placed on the implementation of passive-based water and nutrient support systems and techniques, which can be used to minimize demands on power, mass, and operational complexity in space flight studies. This effort has direct application to the development of next-generation space flight plant chambers such as the Plant Research Unit (PRU). Work was also directed at the development of in-flight plant preservation techniques and protocols consistent with the interest in applying recent developments in gene chip micro array technologies. Cultivation technologies and protocols were evaluated in a 55 day space flight plant growth study, conducted on the ISS, mission 9A (10/7/02 - 12/7/02).

  14. Application and development of advanced Lorentz microscopy techniques for the study of magnetic nanostructures

    NASA Astrophysics Data System (ADS)

    Beacham, Robert J.

    This PhD project presents an investigation into the development of magnetic imaging methods in the TEM and their application in imaging narrow domain walls in multilayer magnetic structures. Lorentz microscopy techniques are limited in quantitative magnetic imaging as this generally requires using scanning imaging modes which limits the capability of imaging dynamic processes. The first imaging method developed in this study is a phase gradient technique with the aim of producing quantitative magnetic contrast proportional to the magnetic induction of the sample whilst maintaining a live imaging mode. This method uses a specifically engineered, semi-electron-transparent graded wedge aperture to controllably perturb intensity in the back focal plane. The results of this study found that this method could produce magnetic contrast proportional to the sample induction, however the required gradient of the wedge aperture made this contrast close to the noise level with large associated errors. In the second part of this study we investigated the development of a technique aimed at gaining sub-microsecond temporal resolution within TEMs based on streak imaging. We are using ramped pulsed magnetic fields, applied across nanowire samples to both induce magnetic behaviour and detect the electron beam across the detector with respect to time. We are coupling this with a novel pixelated detector on the TEM in the form of a Medipix/Timepix chip capable of microsecond exposure times without adding noise. Running this detector in integral mode and allowing for practical limitations such as experiment time and aperture stability, the resultant streak images were taken in Fresnel, Foucault and low angle diffraction imaging modes. We found that while this method is theoretically viable, the limiting factor was the contrast of the magnetic signal in the streak and therefore the total image counts. Domain walls (DWs) in synthetic antiferromagnetically (SAF) coupled films patterned as nanowires offer exciting possibilities; the domain walls in these multilayers have narrower widths and reduced magnetostatic energy compared to those in single layer nanowires. In this study Co90Fe10/Ru/Co90Fe10 films were used to investigate the existence and structure of these walls. Nanowires were fabricated in these films and the DW structure was studied with respect to both wire width and varying magnetic layer thickness. It was found that while the DW structure does not appear to vary with the range of wire widths used, it changed significantly with varying thickness.

  15. Advanced numerical modeling and hybridization techniques for third-generation infrared detector pixel arrays

    NASA Astrophysics Data System (ADS)

    Schuster, Jonathan

    Infrared (IR) detectors are well established as a vital sensor technology for military, defense and commercial applications. Due to the expense and effort required to fabricate pixel arrays, it is imperative to develop numerical simulation models to perform predictive device simulations which assess device characteristics and design considerations. Towards this end, we have developed a robust three-dimensional (3D) numerical simulation model for IR detector pixel arrays. We used the finite-difference time-domain technique to compute the optical characteristics including the reflectance and the carrier generation rate in the device. Subsequently, we employ the finite element method to solve the drift-diffusion equations to compute the electrical characteristics including the I(V) characteristics, quantum efficiency, crosstalk and modulation transfer function. We use our 3D numerical model to study a new class of detector based on the nBn-architecture. This detector is a unipolar unity-gain barrier device consisting of a narrow-gap absorber layer, a wide-gap barrier layer, and a narrow-gap collector layer. We use our model to study the underlying physics of these devices and to explain the anomalously long lateral collection lengths for photocarriers measured experimentally. Next, we investigate the crosstalk in HgCdTe photovoltaic pixel arrays employing a photon-trapping (PT) structure realized with a periodic array of pillars intended to provide broadband operation. The PT region drastically reduces the crosstalk; making the use of the PT structures not only useful to obtain broadband operation, but also desirable for reducing crosstalk, especially in small pitch detector arrays. Then, the power and flexibility of the nBn architecture is coupled with a PT structure to engineer spectrally filtering detectors. Last, we developed a technique to reduce the cost of large-format, high performance HgCdTe detectors by nondestructively screen-testing detector arrays prior to their final hybridization onto expensive silicon read-out integrated circuit (ROIC) chips. The approach is to temporarily hybridize each candidate HgCdTe detector array to a standard reusable ROIC for complete screen testing. We tested the technique by temporarily hybridizing LPE grown HgCdTe test chips to fan-out boards and characterizing their performance.

  16. A miRNA Signature of Chemoresistant Mesenchymal Phenotype Identifies Novel Molecular Targets Associated with Advanced Pancreatic Cancer

    PubMed Central

    Bera, Alakesh; VenkataSubbaRao, Kolaparthi; Manoharan, Muthu Saravanan; Hill, Ping; Freeman, James W.

    2014-01-01

    In this study a microRNA (miRNA) signature was identified in a gemcitabine resistant pancreatic ductal adenocarcinoma (PDAC) cell line model (BxPC3-GZR) and this signature was further examined in advanced PDAC tumor specimens from The Cancer Genome Atlas (TCGA) database. BxPC3-GZR showed a mesenchymal phenotype, expressed high levels of CD44 and showed a highly significant deregulation of 17 miRNAs. Based on relevance to cancer, a seven-miRNA signature (miR-100, miR-125b, miR-155, miR-21, miR-205, miR-27b and miR-455-3p) was selected for further studies. A strong correlation was observed for six of the seven miRNAs in 43 advanced tumor specimens compared to normal pancreas tissue. To assess the functional relevance we initially focused on miRNA-125b, which is over-expressed in both the BxPC3-GZR model and advanced PDAC tumor specimens. Knockdown of miRNA-125b in BxPC3-GZR and Panc-1 cells caused a partial reversal of the mesenchymal phenotype and enhanced response to gemcitabine. Moreover, RNA-seq data from each of 40 advanced PDAC tumor specimens from the TCGA data base indicate a negative correlation between expression of miRNA-125b and five of six potential target genes (BAP1, BBC3, NEU1, BCL2, STARD13). Thus far, two of these target genes, BBC3 and NEU1, that are tumor suppressor genes but not yet studied in PDAC, appear to be functional targets of miR-125b since knockdown of miR125b caused their up regulation. These miRNAs and their molecular targets may serve as targets to enhance sensitivity to chemotherapy and reduce metastatic spread. PMID:25184537

  17. Advanced electron microscopic techniques provide a deeper insight into the peculiar features of podocytes.

    PubMed

    Burghardt, Tillmann; Hochapfel, Florian; Salecker, Benjamin; Meese, Christine; Gröne, Hermann-Josef; Rachel, Reinhard; Wanner, Gerhard; Krahn, Michael P; Witzgall, Ralph

    2015-12-15

    Podocytes constitute the outer layer of the glomerular filtration barrier, where they form an intricate network of interdigitating foot processes which are connected by slit diaphragms. A hitherto unanswered puzzle concerns the question of whether slit diaphragms are established between foot processes of the same podocyte or between foot processes of different podocytes. By employing focused ion beam-scanning electron microscopy (FIB-SEM), we provide unequivocal evidence that slit diaphragms are formed between foot processes of different podocytes. We extended our investigations of the filtration slit by using dual-axis electron tomography of human and mouse podocytes as well as of Drosophila melanogaster nephrocytes. Using this technique, we not only find a single slit diaphragm which spans the filtration slit around the whole periphery of the foot processes but additional punctate filamentous contacts between adjacent foot processes. Future work will be necessary to determine the proteins constituting the two types of cell-cell contacts. PMID:26400546

  18. Development of a corrosion detection experiment to evaluate conventional and advanced NDI techniques

    SciTech Connect

    Roach, D.

    1995-12-31

    The Aging Aircraft NDI Validation Center (AANC) was established by the Federal Aviation Administration Technical Center (FAATC) at Sandia National Laboratories in August of 1991. The goal of the AANC is to provide independent validation of technologies intended to enhance the structural inspection of aging commuter and transport aircraft. The deliverables from the AANC`s validation activities are assessments of the reliability of existing and emerging inspection technologies as well as analyses of the cost benefits to be derived from their implementation. This paper describes the methodology developed by the AANC to assess the performance of NDI techniques. In particular, an experiment being developed to evaluate corrosion detection devices will be presented. The experiment uses engineered test specimens, as well as complete aircraft test beds to provide metrics for NDI validation.

  19. Advanced laser techniques from semiconductor manufacturing transition to solar PV production

    NASA Astrophysics Data System (ADS)

    Mendes, Marco; Slagle, Rick; Fu, Jie; Porneala, Christian; Song, Xiangyang; Hannon, Mat; Sercel, Jeff

    2010-02-01

    For semiconductor manufacturing, a mature industry, a number of laser techniques are employed in production. Diodepumped solid-state (DPSS) lasers are used in applications that cannot be performed by mechanical, chemical, or other laser fabrication methods as well as where they add value through increased throughput and/or improved process quality. Applications such as edge isolation, wafer scribing/dicing, via formation, laser doping and annealing for Semicon are being applied to crystalline silicon PV manufacture as well as research and development for the next generation of high efficiency cells. Similarly, selective material removal for exposing underlying layers without thermal damage is vital in the production of thin film PV panels. In this paper, some of the most important applications of lasers along with experimental results will be reviewed to illustrate how laser methods can have a significant impact on the development and productivity of the photovoltaic industry.

  20. Fault detection in heavy duty wheels by advanced vibration processing techniques and lumped parameter modeling

    NASA Astrophysics Data System (ADS)

    Malago`, M.; Mucchi, E.; Dalpiaz, G.

    2016-03-01

    Heavy duty wheels are used in applications such as automatic vehicles and are mainly composed of a polyurethane tread glued to a cast iron hub. In the manufacturing process, the adhesive application between tread and hub is a critical assembly phase, since it is completely made by an operator and a contamination of the bond area may happen. Furthermore, the presence of rust on the hub surface can contribute to worsen the adherence interface, reducing the operating life. In this scenario, a quality control procedure for fault detection to be used at the end of the manufacturing process has been developed. This procedure is based on vibration processing techniques and takes advantages of the results of a lumped parameter model. Indicators based on cyclostationarity can be considered as key parameters to be adopted in a monitoring test station at the end of the production line due to their not deterministic characteristics.

  1. Development of advanced techniques for rotorcraft state estimation and parameter identification

    NASA Technical Reports Server (NTRS)

    Hall, W. E., Jr.; Bohn, J. G.; Vincent, J. H.

    1980-01-01

    An integrated methodology for rotorcraft system identification consists of rotorcraft mathematical modeling, three distinct data processing steps, and a technique for designing inputs to improve the identifiability of the data. These elements are as follows: (1) a Kalman filter smoother algorithm which estimates states and sensor errors from error corrupted data. Gust time histories and statistics may also be estimated; (2) a model structure estimation algorithm for isolating a model which adequately explains the data; (3) a maximum likelihood algorithm for estimating the parameters and estimates for the variance of these estimates; and (4) an input design algorithm, based on a maximum likelihood approach, which provides inputs to improve the accuracy of parameter estimates. Each step is discussed with examples to both flight and simulated data cases.

  2. Beam profile measurements on the advanced test accelerator using optical techniques

    SciTech Connect

    Chong, Y.P.; Kalibjian, R.; Cornish, J.P.; Kallman, J.S.; Donnelly, D.

    1986-01-01

    Beam current density profiles of ATA have been measured both spatially and temporally using a number of diagnostics. An extremely important technique involves measuring optical emissions from either a target foil inserted into the beam path or gas atoms and molecules excited by beam electrons. This paper describes the detection of the optical emission. A 2-D gated television camera with a single or dual micro-channel-plate (MCP) detector for high gain provides excellent spatial and temporal resolution. Measurements are routinely made with resolutions of 1 mm and 5 ns respectively. The optical line of sight allows splitting part of the signal to a streak camera or photometer for even higher time resolution.

  3. Combustion synthesis of advanced materials. [using in-situ infiltration technique

    NASA Technical Reports Server (NTRS)

    Moore, J. J.; Feng, H. J.; Perkins, N.; Readey, D. W.

    1992-01-01

    The combustion synthesis of ceramic-metal composites using an in-situ liquid infiltration technique is described. The effect of varying the reactants and their stoichiometry to provide a range of reactant and product species i.e. solids, liquids and gases, with varying physical properties e.g. thermal conductivity, on the microstructure and morphology of synthesized products is also described. Alternatively, conducting the combustion synthesis reaction in a reactive gas environment is also discussed, in which advantages can be gained from the synergistic effects of combustion synthesis and vapor phase transport. In each case, the effect of the presence or absence of gravity (density) driven fluid flow and vapor transport is discussed as is the potential for producing new and perhaps unique materials by conducting these SHS reactions under microgravity conditions.

  4. Advances in Airborne Altimetric Techniques for the Measurement of Snow on Arctic Sea Ice

    NASA Astrophysics Data System (ADS)

    Newman, T.; Farrell, S. L.; Richter-Menge, J.; Elder, B. C.; Ruth, J.; Connor, L. N.

    2014-12-01

    Current sea ice observations and models indicate a transition towards a more seasonal Arctic ice pack with a smaller, and geographically more variable, multiyear ice component. To gain a comprehensive understanding of the processes governing this transition it is important to include the impact of the snow cover, determining the mechanisms by which snow is both responding to and forcing changes to the sea ice pack. Data from NASA's Operation IceBridge (OIB) snow radar system, which has been making yearly surveys of the western Arctic since 2009, offers a key resource for investigating the snow cover. In this work, we characterize the OIB snow radar instrument response to ascertain the location of 'side-lobes', aiding the interpretation of snow radar data. We apply novel wavelet-based techniques to identify the primary reflecting interfaces within the snow pack from which snow depth estimates are derived. We apply these techniques to the range of available snow radar data collected over the last 6 years during the NASA OIB mission. Our results are validated through comparison with a range of in-situ data. We discuss the impact of sea ice surface morphology on snow radar returns (with respect to ice type) and the topographic conditions over which accurate snow-radar-derived snow depths may be obtained. Finally we present improvements to in situ survey design that will allow for both an improved sampling of the snow radar footprint and more accurate assessment of the uncertainties in radar-derived snow depths in the future.

  5. MULTIPOLE EXPANSION TECHNIQUES FOR THE CALCULATION AND CHARACTERIZATION OF MOLECULAR ELECTROSTATIC POTENTIALS

    EPA Science Inventory

    The electrostatic interaction between a chemical and its site of biological action is often important in determining biological activity. In order to include this interaction in methods to assess the potential biological activity of large molecules, rapid and reliable techniques ...

  6. Recent advances in the molecular imaging of programmed cell death: part I--pathophysiology and radiotracers.

    PubMed

    Blankenberg, Francis G; Strauss, H William

    2012-11-01

    In humans, apoptosis (programmed cell death) is the most common form of cell death after necrosis. Apoptosis is a series of genetically preprogrammed biochemical and morphologic energy-requiring events that, after a specific external or internal stimulus, results in the physiologic disappearance of a cell via its self-disintegration and packaging of its contents into membrane vesicles called apoptotic bodies. Apoptotic bodies can readily be ingested, with their nutrients and even organelles recycled by neighboring cells or phagocytes without local inflammation. In contrast, necrosis is characterized by the primary loss of plasma membrane integrity and the uncontrolled release of a cell's contents, often causing local inflammation, tissue damage, and scarring. Alternate forms of cell death also exist, associated with specific molecular mechanisms involving enzymes, organelles, genes, external stimuli, or blockade of normal cell proliferation. In this review we will briefly outline the molecular mechanisms of apoptosis that can be imaged with radiotracers now under development. PMID:23033360

  7. Technical Needs for Prototypic Prognostic Technique Demonstration for Advanced Small Modular Reactor Passive Components

    SciTech Connect

    Meyer, Ryan M.; Coble, Jamie B.; Hirt, Evelyn H.; Ramuhalli, Pradeep; Mitchell, Mark R.; Wootan, David W.; Berglin, Eric J.; Bond, Leonard J.; Henager, Charles H.

    2013-05-17

    This report identifies a number of requirements for prognostics health management of passive systems in AdvSMRs, documents technical gaps in establishing a prototypical prognostic methodology for this purpose, and describes a preliminary research plan for addressing these technical gaps. AdvSMRs span multiple concepts; therefore a technology- and design-neutral approach is taken, with the focus being on characteristics that are likely to be common to all or several AdvSMR concepts. An evaluation of available literature is used to identify proposed concepts for AdvSMRs along with likely operational characteristics. Available operating experience of advanced reactors is used in identifying passive components that may be subject to degradation, materials likely to be used for these components, and potential modes of degradation of these components. This information helps in assessing measurement needs for PHM systems, as well as defining functional requirements of PHM systems. An assessment of current state-of-the-art approaches to measurements, sensors and instrumentation, diagnostics and prognostics is also documented. This state-of-the-art evaluation, combined with the requirements, may be used to identify technical gaps and research needs in the development, evaluation, and deployment of PHM systems for AdvSMRs. A preliminary research plan to address high-priority research needs for the deployment of PHM systems to AdvSMRs is described, with the objective being the demonstration of prototypic prognostics technology for passive components in AdvSMRs. Greater efficiency in achieving this objective can be gained through judicious selection of materials and degradation modes that are relevant to proposed AdvSMR concepts, and for which significant knowledge already exists. These selections were made based on multiple constraints including the analysis performed in this document, ready access to laboratory-scale facilities for materials testing and measurement, and potential synergies with other national laboratory and university partners.

  8. Techniques and Outcome of Surgery for Locally Advanced and Local Recurrent Rectal Cancer.

    PubMed

    Renehan, A G

    2016-02-01

    Locally advanced primary rectal cancer is variably defined, but generally refers to T3 and T4 tumours. Radical surgery is the mainstay of treatment for these tumours but there is a high-risk for local recurrence. National Institute for Health and Care Excellence (2011) guidelines recommend that patients with these tumours be considered for preoperative chemoradiotherapy and this is the starting point for any discussion, as it is standard care. However, there are many refinements of this pathway and these are the subject of this overview. In surgical terms, there are two broad settings: (i) patients with tumours contained within the mesorectal envelope, or in the lower rectum, limited to invading the sphincter muscles (namely some T2 and most T3 tumours); and (ii) patients with tumours directly invading or adherent to pelvic organs or structures, mainly T4 tumours - here referred to as primary rectal cancer beyond total mesorectal excision (PRC-bTME). Major surgical resection using the principles of TME is the mainstay of treatment for the former. Where anal sphincter sacrifice is indicated for low rectal cancers, variations of abdominoperineal resection - referred to as tailored excision - including the extralevator abdominoperineal excision (ELAPE), are required. There is debate whether or not plastic reconstruction or mesh repair is required after these surgical procedures. To achieve cure in PRC-bTME tumours, most patients require extended multivisceral exenterative surgery, carried out within specialist multidisciplinary centres. The surgical principles governing the treatment of recurrent rectal cancer (RRC) parallel those for PRC-bTME, but typically only half of these patients are suitable for this type of major surgery. Peri-operative morbidity and mortality are considerable after surgery for PRC-bTME and RRC, but unacceptable levels of variation in clinical practice and outcome exist globally. To address this, there are now major efforts to standardise terminology and classifications, to allow appropriate comparisons in future studies. PMID:26683258

  9. NCCN Task Force Report: Optimizing Treatment of Advanced Renal Cell Carcinoma With Molecular Targeted Therapy

    PubMed Central

    Hudes, Gary R.; Carducci, Michael A.; Choueiri, Toni K.; Esper, Peg; Jonasch, Eric; Kumar, Rashmi; Margolin, Kim A.; Michaelson, M. Dror; Motzer, Robert J.; Pili, Roberto; Roethke, Susan; Srinivas, Sandy

    2015-01-01

    The outcome of patients with metastatic renal cell carcinoma has been substantially improved with administration of the currently available molecularly targeted therapies. However, proper selection of therapy and management of toxicities remain challenging. NCCN convened a multidisciplinary task force panel to address the clinical issues associated with these therapies in attempt to help practicing oncologists optimize patient outcomes. This report summarizes the background data presented at the task force meeting and the ensuing discussion. PMID:21335444

  10. Covalent molecular probes for class A G protein-coupled receptors: advances and applications.

    PubMed

    Weichert, Dietmar; Gmeiner, Peter

    2015-06-19

    Covalent modification of G protein-coupled receptors (GPCRs) by employing specific molecular probes has for decades provided a successful strategy to facilitate the elucidation of the structure and function of this pharmacologically important class of membrane proteins. The ligands typically comprise a pharmacophore that generates affinity for a given GPCR and contain a reactive functionality that may form a covalent bond with a suitably positioned amino acid residue. Covalent ligands have been successfully applied to circumvent poor affinity of compounds when stable labeling of receptor populations was required, and they have been used in the isolation, purification, and pharmacological characterization of specific subtypes of GPCRs. Recently, structural studies have demonstrated that covalent molecular probes are effective at stabilizing GPCRs to obtain X-ray crystal structures, thus providing valuable insights for the development of novel therapeutics. Herein, we review covalently binding molecular probes for class A GPCRs with a focus on ligands comprising cross-linking groups that do not require photoactivation and further highlight their significant and diverse applications. PMID:25860503

  11. Molecular Dynamics Simulations of Guanine Quadruplex Loops: Advances and Force Field Limitations

    PubMed Central

    Fadrná, Eva; Špa?ková, Nad'a; Štefl, Richard; Ko?a, Jaroslav; Cheatham, Thomas E.; Šponer, Ji?í

    2004-01-01

    A computational analysis of d(GGGGTTTTGGGG)2 guanine quadruplexes containing either lateral or diagonal four-thymidine loops was carried out using molecular dynamics (MD) simulations in explicit solvent, locally enhanced sampling (LES) simulations, systematic conformational search, and free energy molecular-mechanics, Poisson Boltzmann, surface area (MM-PBSA) calculations with explicit inclusion of structural monovalent cations. The study provides, within the approximations of the applied all-atom additive force field, a qualitatively complete analysis of the available loop conformational space. The results are independent of the starting structures. Major conformational transitions not seen in conventional MD simulations are observed when LES is applied. The favored LES structures consistently provide lower free energies (as estimated by molecular-mechanics, Poisson Boltzmann, surface area) than other structures. Unfortunately, the predicted optimal structure for the diagonal loop arrangement differs substantially from the atomic resolution experiments. This result is attributed to force field deficiencies, such as the potential misbalance between solute-cation and solvent-cation terms. The MD simulations are unable to maintain the stable coordination of the monovalent cations inside the diagonal loops as reported in a recent x-ray study. The optimal diagonal and lateral loop arrangements appear to be close in energy although a proper inclusion of the loop monovalent cations could stabilize the diagonal architecture. PMID:15240460

  12. Analysis of the REJ Module of Polycystin-1 Using Molecular Modeling and Force-Spectroscopy Techniques

    PubMed Central

    Xu, Meixiang; Ma, Liang; Bujalowski, Paul J.; Sutton, R. Bryan; Oberhauser, Andres F.

    2013-01-01

    Polycystin-1 is a large transmembrane protein, which, when mutated, causes autosomal dominant polycystic kidney disease, one of the most common life-threatening genetic diseases that is a leading cause of kidney failure. The REJ (receptor for egg lelly) module is a major component of PC1 ectodomain that extends to about 1000 amino acids. Many missense disease-causing mutations map to this module; however, very little is known about the structure or function of this region. We used a combination of homology molecular modeling, protein engineering, steered molecular dynamics (SMD) simulations, and single-molecule force spectroscopy (SMFS) to analyze the conformation and mechanical stability of the first ~420 amino acids of REJ. Homology molecular modeling analysis revealed that this region may contain structural elements that have an FNIII-like structure, which we named REJd1, REJd2, REJd3, and REJd4. We found that REJd1 has a higher mechanical stability than REJd2 (~190 pN and 60 pN, resp.). Our data suggest that the putative domains REJd3 and REJd4 likely do not form mechanically stable folds. Our experimental approach opens a new way to systematically study the effects of disease-causing mutations on the structure and mechanical properties of the REJ module of PC1. PMID:23762046

  13. Molecular self-assembly of conducting polymer by Conducting Probe Technique in Atomic Force Microscope

    NASA Astrophysics Data System (ADS)

    Yamamoto, Shin-ichi; Ogawa, Kazufumi

    2007-04-01

    A polypyrrole derivative monolayer was investigated for the application as a wire. First, a pyrrole derivative monolayer was prepared by chemically adsorbing (self-assembling) monolayer (CAM) of 6-pyrrolylhexyl-12,12,12-trichloro-12- siladodecanoate (PEN) on a glass substrate. Then, the monolayer was polymerized in the presence of pure water by electrooxidation. The surface characterization of the molecular interaction was investigated by measuring the properties of CAMs attached to the glass substrate in the lateral direction. We formed PEN having polypyrrolyl groups, using Pt-patterned electrodes on glass surfaces and measured the conductance under a small bias voltage, using a conductive cantilever of atomic force microscopy (AFM). The polypyrrole derivative monolayer thus synthesized was covalently bonded to the glass substrate and showed conductivity as high as 3.05..103 S/cm after electro-oxidized. The method of preparing a conductive polymer monolayer by the combining chemical adsorption and electro-oxidation leads to a lot molecular wire to perpendicular to the Pt electrodes, and it is one of the key technologies for molecular devices.

  14. Therapeutic efficacy of a hybrid mandibular advancement device in the management of obstructive sleep apnea assessed with acoustic reflection technique.

    PubMed

    Agarwal, S S; Jayan, B; Kumar, Sunil

    2015-01-01

    Obstructive sleep apnea (OSA) is one of the most common forms of sleep-disordered breathing. Various treatment modalities include behavior modification therapy, nasal continuous positive airway pressure (CPAP), oral appliance therapy, and various surgical modalities. Oral appliances are noninvasive and recommended treatment modality for snoring, mild to moderate OSA cases and severe OSA cases when patient is not compliant to CPAP therapy and unwilling for surgery. Acoustic reflection technique (ART) is a relatively new modality for three-dimensional assessment of airway caliber in various clinical situations. The accuracy and reproducibility of acoustic rhinometry and acoustic pharyngometry assessment are comparable to computerized tomography and magnetic resonance imaging. This case report highlights the therapeutic efficacy of an innovative customized acrylic hybrid mandibular advancement device in the management of polysomnography diagnosed OSA cases, and the treatment results were assessed by ART. PMID:25961623

  15. Design of a dedicated beamline for x-ray microfocusing- and coherence- based techniques at the Advanced Photon Source

    SciTech Connect

    Yun, W.; Lai, B.; Shu, D.; Khounsary, A.; Cai, J.; Barraza, J.; Legnini, D.

    1995-12-31

    A dedicated insertion-device beamline has been designed and is being constructed at the Advanced Photon Source (APS) for development of x- ray microfocusing- and coherence-based techniques and applications. Important parameters considered in this design include preservation of source brilliance and coherence, selectable transverse coherence length and energy bandwidth, high beam angular stability, high order harmonic suppression, quick x-ray energy scan, and accurate and stable x-ray energy. The overall design of this beamline layout and the major beamline components are described. The use of a horizontally deflecting mirror as the first optical component is one of the main features of this beamline design, and the resulting advantages are briefly discussed.

  16. Fuel Injector Patternation Evaluation in Advanced Liquid-Fueled, High Pressure, Gas Turbine Combustors, Using Nonintrusive Optical Diagnostic Techniques

    NASA Technical Reports Server (NTRS)

    Locke, R. J.; Hicks, Y. R.; Anderson, R. C.; Zaller, M. M.

    1998-01-01

    Planar laser-induced fluorescence (PLIF) imaging and planar Mie scattering are used to examine the fuel distribution pattern (patternation) for advanced fuel injector concepts in kerosene burning, high pressure gas turbine combustors. Three diverse fuel injector concepts for aerospace applications were investigated under a broad range of operating conditions. Fuel PLIF patternation results are contrasted with those obtained by planar Mie scattering. Further comparison is also made for one injector with data obtained through phase Doppler measurements. Differences in spray patterns for diverse conditions and fuel injector configurations are readily discernible. An examination of the data has shown that a direct determination of the fuel spray angle at realistic conditions is also possible. The results obtained in this study demonstrate the applicability and usefulness of these nonintrusive optical techniques for investigating fuel spray patternation under actual combustor conditions.

  17. Advancement and application of gas chromatography isotope ratio mass spectrometry techniques for atmospheric trace gas analysis

    NASA Astrophysics Data System (ADS)

    Giebel, Brian M.

    2011-12-01

    The use of gas chromatography isotope ratio mass spectrometry (GC-IRMS) for compound specific stable isotope analysis is an underutilized technique because of the complexity of the instrumentation and high analytical costs. However stable isotopic data, when coupled with concentration measurements, can provide additional information on a compounds production, transformation, loss, and cycling within the biosphere and atmosphere. A GC-IRMS system was developed to accurately and precisely measure delta13C values for numerous oxygenated volatile organic compounds having natural and anthropogenic sources. The OVOCs include methanol, ethanol, acetone, methyl ethyl ketone, 2-pentanone, and 3-pentanone. Guided by the requirements for analysis of trace components in air, the GC-IRMS system was developed with the goals of increasing sensitivity, reducing dead-volume and peak band broadening, optimizing combustion and water removal, and decreasing the split ratio to the IRMS. The technique relied on a two-stage preconcentration system, a low-volume capillary reactor and water trap, and a balanced reference gas delivery system. Measurements were performed on samples collected from two distinct sources (i.e. biogenic and vehicle emissions) and ambient air collected from downtown Miami and Everglades National Park. However, the instrumentation and the method have the capability to analyze a variety of source and ambient samples. The measured isotopic signatures that were obtained from source and ambient samples provide a new isotopic constraint for atmospheric chemists and can serve as a new way to evaluate their models and budgets for many OVOCs. In almost all cases, OVOCs emitted from fuel combustion were enriched in 13C when compared to the natural emissions of plants. This was particularly true for ethanol gas emitted in vehicle exhaust, which was observed to have a uniquely enriched isotopic signature that was attributed to ethanol's corn origin and use as an alternative fuel or fuel additive. Results from this effort show that ethanol's unique isotopic signature can be incorporated into air chemistry models for fingerprinting and source apportionment purposes and can be used as a stable isotopic tracer for biofuel inputs to the atmosphere on local to regional scales.

  18. Advanced InSAR techniques for the management and characterization of geothermal resources

    NASA Astrophysics Data System (ADS)

    Bellotti, F.; Falorni, G.; Morgan, J.; Rucci, A.; Ferretti, A.

    2012-04-01

    InSAR is a remote sensing tool that has applications in both geothermal exploitation and in the management of producing fields. The technique has developed rapidly in recent years and the most evolved algorithms, now capable of providing precise ground movement measurements with unprecedented spatial density over large areas, allow the monitoring of the effects of fluid injection and extraction on surface deformation and the detection of active faults. Multi-interferogram approaches have been used at several geothermal sites in different stages of development. SqueeSAR™, which represents the latest breakthrough in InSAR technology, provides a significant increase in the spatial density of measurement points by exploiting signal returns from both point-like and distributed scatterers. Furthermore, recent satellite radar sensors have a higher spatial resolution (down to 1 m), as well as a higher temporal frequency of image acquisitions (down to a few days). The coupling of the new algorithm with this new generation of satellites provides a valuable tool for monitoring the different phases of geothermal production and in support of the decision making process. Some examples from the US are presented here: the first case study involves the use of InSAR within a suite of tools for exploration of the San Emidio geothermal field in Nevada. This project aimed to develop geophysical techniques to identify and map large aperture fractures for the placement of new production/exploration wells. The second and third examples examine two zones in California: the Salton Sea area, where multi-interferogram InSAR provided an overview of surface deformation at a producing geothermal reservoir. Surface deformation in this area was complex, and the added detail provided insight into the interplay of tectonics and production activities. Additional InSAR studies have also been carried out at the Geysers field in order to evaluate the behavior of an Enhanced Geothermal System (EGS) in response to high rates of water injection, with a strong interest in researching induced seismicity and ground deformation. These studies, along with the continuing developments in radar satellite technology and in the field of InSAR, show considerable promise for the future monitoring of geothermal production facilities.

  19. Current advances and future trends in characterizing poorly water-soluble drugs using spectroscopic, imaging and data analytical techniques.

    PubMed

    Wu, Jian X; van den Berg, Frans; Rantanen, Jukka; Rades, Thomas; Yang, Mingshi

    2014-01-01

    A common feature of many new analytical techniques that allows fast and non-destructive analysis of poorly-water-soluble drug is that they generate a large amount of data with a multivariate character within a short time frame, which in turn highlights the need for advanced data analytical methods in extracting information from the complex data set. The current review critically examines how spectroscopy and imaging techniques can be utilized for fast and non-destructive characterization of solid state poorly water-soluble drug formulations. The first part of the present review describes the basics behind many of the currently used methods including Raman, near infrared (NIR), infrared (IR) spectroscopy and X-ray powder diffractometry in characterizing poorly water soluble drugs. Key emphasis was placed on a critical review of the currently used spectral preprocessing methods, and the influence of selected preprocessing on spectral data sets is exemplified. Further the existing uni- and multivariate spectral data analytical methods in analyzing complex spectral data sets are reviewed, covering estimation of spectral peak moments, peak modeling, variations of Principal Component Analysis (PCA), variations of Partial Least Squares (PLS) analysis and Multivariate Curve Resolution (MCR). The second part of the present review discusses hyperspectral imaging, UV imaging, optical microscopy imaging and process imaging methods suitable for characterization of poorly water-soluble solid state drug formulations. Image analytical techniques suitable for analyzing hyperspectral image data set are described. Further, the application of various image analytical techniques leading to the estimation of nucleation and crystal growth rates from polarized light microscopy is described. PMID:23651397

  20. Characterization of natural resin materials using water adsorption and various advanced techniques

    NASA Astrophysics Data System (ADS)

    Favvas, Evangelos P.; Kouvelos, Evangelos P.; Papageorgiou, Sergios K.; Tsanaktsidis, Constantinos G.; Mitropoulos, Athanasios Ch.

    2015-05-01

    A physicochemical characterization of natural raw resin material was evaluated and reported. The studied material is a natural resin, a natural product from pinus halepensis trees which is collected from the forests of Chalkidiki region of North Greece. The plurality of this product combined with its special property of removing water from commercial liquid fuels commands the detailed physicochemical characterization of this material. In particular, various techniques, such as water adsorption at 22 °C, thermogravimetric analysis, differential scanning calorimetry, Fourier transform infrared spectroscopy and X-ray diffraction, were used in order to evaluate the structural and surface properties of the material. The water adsorption isotherm was also measured and fitted using the Guggenheim, Anderson and De Boer model in order to correlate the water activity characteristics. In addition, the kinetics of the adsorption was also fitted with good accuracy using the exponential Chapman model. Furthermore, as the results show, the natural resin presents good thermal characteristics. Finally, the studied material presents efficient water adsorption properties, up to 246.8 mmol/g, and it can be proposed as a promising dehydration material.

  1. Application of advanced grid generation techniques for flow field computations about complex configurations

    NASA Technical Reports Server (NTRS)

    Kathong, Monchai; Tiwari, Surendra N.

    1988-01-01

    In the computation of flowfields about complex configurations, it is very difficult to construct a boundary-fitted coordinate system. An alternative approach is to use several grids at once, each of which is generated independently. This procedure is called the multiple grids or zonal grids approach; its applications are investigated. The method conservative providing conservation of fluxes at grid interfaces. The Euler equations are solved numerically on such grids for various configurations. The numerical scheme used is the finite-volume technique with a three-stage Runge-Kutta time integration. The code is vectorized and programmed to run on the CDC VPS-32 computer. Steady state solutions of the Euler equations are presented and discussed. The solutions include: low speed flow over a sphere, high speed flow over a slender body, supersonic flow through a duct, and supersonic internal/external flow interaction for an aircraft configuration at various angles of attack. The results demonstrate that the multiple grids approach along with the conservative interfacing is capable of computing the flows about the complex configurations where the use of a single grid system is not possible.

  2. Integrative Utilization of Microenvironments, Biomaterials and Computational Techniques for Advanced Tissue Engineering.

    PubMed

    Shamloo, Amir; Mohammadaliha, Negar; Mohseni, Mina

    2015-10-20

    This review aims to propose the integrative implementation of microfluidic devices, biomaterials, and computational methods that can lead to a significant progress in tissue engineering and regenerative medicine researches. Simultaneous implementation of multiple techniques can be very helpful in addressing biological processes. Providing controllable biochemical and biomechanical cues within artificial extracellular matrix similar to in vivo conditions is crucial in tissue engineering and regenerative medicine researches. Microfluidic devices provide precise spatial and temporal control over cell microenvironment. Moreover, generation of accurate and controllable spatial and temporal gradients of biochemical factors is attainable inside microdevices. Since biomaterials with tunable properties are a worthwhile option to construct artificial extracellular matrix, in vitro platforms that simultaneously utilize natural, synthetic, or engineered biomaterials inside microfluidic devices are phenomenally advantageous to experimental studies in the field of tissue engineering. Additionally, collaboration between experimental and computational methods is a useful way to predict and understand mechanisms responsible for complex biological phenomena. Computational results can be verified by using experimental platforms. Computational methods can also broaden the understanding of the mechanisms behind the biological phenomena observed during experiments. Furthermore, computational methods are powerful tools to optimize the fabrication of microfluidic devices and biomaterials with specific features. Here we present a succinct review of the benefits of microfluidic devices, biomaterial, and computational methods in the case of tissue engineering and regeneration medicine. Furthermore, some breakthroughs in biological phenomena including the neuronal axon development, cancerous cell migration and blood vessel formation via angiogenesis by virtue of the aforementioned approaches are discussed. PMID:26281975

  3. Advanced Techniques for Seismic Protection of Historical Buildings: Experimental and Numerical Approach

    SciTech Connect

    Mazzolani, Federico M.

    2008-07-08

    The seismic protection of historical and monumental buildings, namely dating back from the ancient age up to the 20th Century, is being looked at with greater and greater interest, above all in the Euro-Mediterranean area, its cultural heritage being strongly susceptible to undergo severe damage or even collapse due to earthquake. The cultural importance of historical and monumental constructions limits, in many cases, the possibility to upgrade them from the seismic point of view, due to the fear of using intervention techniques which could have detrimental effects on their cultural value. Consequently, a great interest is growing in the development of sustainable methodologies for the use of Reversible Mixed Technologies (RMTs) in the seismic protection of the existing constructions. RMTs, in fact, are conceived for exploiting the peculiarities of innovative materials and special devices, and they allow ease of removal when necessary. This paper deals with the experimental and numerical studies, framed within the EC PROHITECH research project, on the application of RMTs to the historical and monumental constructions mainly belonging to the cultural heritage of the Euro-Mediterranean area. The experimental tests and the numerical analyses are carried out at five different levels, namely full scale models, large scale models, sub-systems, devices, materials and elements.

  4. The Conqueror Worm: recent advances with cholinergic anthelmintics and techniques excite research for better therapeutic drugs

    PubMed Central

    Martin, R.J.; Puttachary, S.; Buxton, S.K.; Verma, S.; Robertson, A.P.

    2014-01-01

    The following account is based on a review lecture given recently at the British Society of Parasitology. We point out that nematode parasites cause very widespread infections of humans, particularly in economically underdeveloped areas where sanitation and hygiene are not adequate. In the absence of adequate clean water and effective vaccines, control and prophylaxis relies on anthelmintic drugs. Widespread use of anthelmintics to control nematode parasites of animals has given rise to the development of resistance and so there is a concern that similar problems will occur in humans if mass drug administration is continued. Recent research on the cholinergic anthelmintic drugs has renewed enthusiasm for the further development of cholinergic anthelmintics. Here we illustrate the use of three parasite nematode models, Ascaris suum, Oesophagostomum dentatum and Brugia malayi, microfluidic techniques and the Xenopus oocyte expression system for testing and examining the effects of cholinergic anthelmintics. We also show how the combination of derquantel, the selective nematode cholinergic antagonist and abamectin produce increased inhibition of the nicotinic acetylcholine receptors on the nematode body muscle. We are optimistic that new compounds and combinations of compounds can limit the effects of drug resistance, allowing anthelmintics to be continued to be used for effective treatment of human and animal helminth parasites. PMID:24871674

  5. Advanced Techniques for Seismic Protection of Historical Buildings: Experimental and Numerical Approach

    NASA Astrophysics Data System (ADS)

    Mazzolani, Federico M.

    2008-07-01

    The seismic protection of historical and monumental buildings, namely dating back from the ancient age up to the 20th Century, is being looked at with greater and greater interest, above all in the Euro-Mediterranean area, its cultural heritage being strongly susceptible to undergo severe damage or even collapse due to earthquake. The cultural importance of historical and monumental constructions limits, in many cases, the possibility to upgrade them from the seismic point of view, due to the fear of using intervention techniques which could have detrimental effects on their cultural value. Consequently, a great interest is growing in the development of sustainable methodologies for the use of Reversible Mixed Technologies (RMTs) in the seismic protection of the existing constructions. RMTs, in fact, are conceived for exploiting the peculiarities of innovative materials and special devices, and they allow ease of removal when necessary. This paper deals with the experimental and numerical studies, framed within the EC PROHITECH research project, on the application of RMTs to the historical and monumental constructions mainly belonging to the cultural heritage of the Euro-Mediterranean area. The experimental tests and the numerical analyses are carried out at five different levels, namely full scale models, large scale models, sub-systems, devices, materials and elements.

  6. Recent advances in controlled synthesis of two-dimensional transition metal dichalcogenides via vapour deposition techniques.

    PubMed

    Shi, Yumeng; Li, Henan; Li, Lain-Jong

    2015-05-01

    In recent years there have been many breakthroughs in two-dimensional (2D) nanomaterials, among which the transition metal dichalcogenides (TMDs) attract significant attention owing to their unusual properties associated with their strictly defined dimensionalities. TMD materials with a generalized formula of MX2, where M is a transition metal and X is a chalcogen, represent a diverse and largely untapped source of 2D systems. Semiconducting TMD monolayers such as MoS2, MoSe2, WSe2 and WS2 have been demonstrated to be feasible for future electronics and optoelectronics. The exotic electronic properties and high specific surface areas of 2D TMDs offer unlimited potential in various fields including sensing, catalysis, and energy storage applications. Very recently, the chemical vapour deposition technique (CVD) has shown great promise to generate high-quality TMD layers with a scalable size, controllable thickness and excellent electronic properties. Wafer-scale deposition of mono to few layer TMD films has been obtained. Despite the initial success in the CVD synthesis of TMDs, substantial research studies on extending the methodology open up a new way for substitution doping, formation of monolayer alloys and producing TMD stacking structures or superlattices. In this tutorial review, we will introduce the latest development of the synthesis of monolayer TMDs by CVD approaches. PMID:25327436

  7. Advanced compilation techniques in the PARADIGM compiler for distributed-memory multicomputers

    NASA Technical Reports Server (NTRS)

    Su, Ernesto; Lain, Antonio; Ramaswamy, Shankar; Palermo, Daniel J.; Hodges, Eugene W., IV; Banerjee, Prithviraj

    1995-01-01

    The PARADIGM compiler project provides an automated means to parallelize programs, written in a serial programming model, for efficient execution on distributed-memory multicomputers. .A previous implementation of the compiler based on the PTD representation allowed symbolic array sizes, affine loop bounds and array subscripts, and variable number of processors, provided that arrays were single or multi-dimensionally block distributed. The techniques presented here extend the compiler to also accept multidimensional cyclic and block-cyclic distributions within a uniform symbolic framework. These extensions demand more sophisticated symbolic manipulation capabilities. A novel aspect of our approach is to meet this demand by interfacing PARADIGM with a powerful off-the-shelf symbolic package, Mathematica. This paper describes some of the Mathematica routines that performs various transformations, shows how they are invoked and used by the compiler to overcome the new challenges, and presents experimental results for code involving cyclic and block-cyclic arrays as evidence of the feasibility of the approach.

  8. Advances in the regionalization approach: geostatistical techniques for estimating flood quantiles

    NASA Astrophysics Data System (ADS)

    Chiarello, Valentina; Caporali, Enrica; Matthies, Hermann G.

    2015-04-01

    The knowledge of peak flow discharges and associated floods is of primary importance in engineering practice for planning of water resources and risk assessment. Streamflow characteristics are usually estimated starting from measurements of river discharges at stream gauging stations. However, the lack of observations at site of interest as well as the measurement inaccuracies, bring inevitably to the necessity of developing predictive models. Regional analysis is a classical approach to estimate river flow characteristics at sites where little or no data exists. Specific techniques are needed to regionalize the hydrological variables over the considered area. Top-kriging or topological kriging, is a kriging interpolation procedure that takes into account the geometric organization and structure of hydrographic network, the catchment area and the nested nature of catchments. The continuous processes in space defined for the point variables are represented by a variogram. In Top-kriging, the measurements are not point values but are defined over a non-zero catchment area. Top-kriging is applied here over the geographical space of Tuscany Region, in Central Italy. The analysis is carried out on the discharge data of 57 consistent runoff gauges, recorded from 1923 to 2014. Top-kriging give also an estimation of the prediction uncertainty in addition to the prediction itself. The results are validated using a cross-validation procedure implemented in the package rtop of the open source statistical environment R The results are compared through different error measurement methods. Top-kriging seems to perform better in nested catchments and larger scale catchments but no for headwater or where there is a high variability for neighbouring catchments.

  9. Seismic response analysis of NAGRA-Net stations using advanced geophysical techniques

    NASA Astrophysics Data System (ADS)

    Poggi, Valerio; Edwards, Benjamin; Dal Moro, Giancarlo; Keller, Lorenz; Fäh, Donat

    2015-04-01

    In cooperation with the National Cooperative for the Disposal of Radioactive Waste (Nagra), the Swiss Seismological Service (SED) has recently completed the installation of ten new seismological observation stations, three of them including a co-located borehole sensor. The ultimate goal of the project is to densify the existing Swiss Digital Seismic Network (SDSNet) in northern Switzerland, in order to improve the detection of very-low magnitude events and to improve the accuracy of future location solutions. This is strategic for unbiased monitoring of micro seismicity at the locations of proposed nuclear waste repositories. To further improve the quality and usability of the recordings, a seismic characterization of the area surrounding the installation area was performed at each site. The investigation consisted of a preliminary geological and geotechnical study, followed by a seismic site response analysis by means of state-of-the-art geophysical techniques. For the borehole stations, in particular, the characterization was performed by combining different types of active seismic methods (P-S refraction tomography, surface wave analysis, Vertical Seismic Profiling - VSP) with ambient vibration based approaches (wavelet decomposition, H/V spectral ratio, polarization analysis, three-component f-k analysis). The results of all analyses converged to the definition of a mean velocity profile for the site, which was later used for the computation of engineering parameters (travel time average velocity and quarter-wavelength parameters) and the analytical SH-wave transfer function. Empirical site-amplification functions are automatically determined for any station connected to the Swiss seismic networks. They are determined based on building statistical models of systematic site-specific effects in recordings of small earthquakes when compared to the Swiss stochastic ground-motion model. Computed site response is validated through comparison with these empirical functions, and finally used to correct recordings before further processing.

  10. Symmetry-Based Techniques for Qualitative Understanding of Rovibrational Effects in Spherical-Top Molecular Spectra and Dynamics

    NASA Astrophysics Data System (ADS)

    Mitchell, Justin Chadwick

    2011-12-01

    Using light to probe the structure of matter is as natural as opening our eyes. Modern physics and chemistry have turned this art into a rich science, measuring the delicate interactions possible at the molecular level. Perhaps the most commonly used tool in computational spectroscopy is that of matrix diagonalization. While this is invaluable for calculating everything from molecular structure and energy levels to dipole moments and dynamics, the process of numerical diagonalization is an opaque one. This work applies symmetry and semi-classical techniques to elucidate numerical spectral analysis for high-symmetry molecules. Semi-classical techniques, such as the Potential Energy Surfaces, have long been used to help understand molecular vibronic and rovibronic spectra and dynamics. This investigation focuses on newer semi-classical techniques that apply Rotational Energy Surfaces (RES) to rotational energy level clustering effects in high-symmetry molecules. Such clusters exist in rigid rotor molecules as well as deformable spherical tops. This study begins by using the simplicity of rigid symmetric top molecules to clarify the classical-quantum correspondence of RES semi-classical analysis and then extends it to a more precise and complete theory of modern high-resolution spectra. RES analysis is extended to molecules having more complex and higher rank tensorial rotational and rovibrational Hamiltonians than were possible to understand before. Such molecules are shown to produce an extraordinary range of rotational level clusters, corresponding to a panoply of symmetries ranging from C4v to C2 and C1 (no symmetry) with a corresponding range of new angular momentum localization and J-tunneling effects. Using RES topography analysis and the commutation duality relations between symmetry group operators in the lab-frame to those in the body-frame, it is shown how to better describe and catalog complex splittings found in rotational level clusters. Symmetry character analysis is generalized to give analytic eigensolutions. An appendix provides vibrational analogies. For the first time, interactions between molecular vibrations (polyads) are described semi-classically by multiple RES. This is done for the nu 3/2nu4 dyad of CF4. The nine-surface RES topology of the U(9)-dyad agrees with both computational and experimental work. A connection between this and a simpler U(2) example is detailed in an Appendix.

  11. MDR-TB screening in a setting with molecular diagnostic techniques: who got tested, who didn't and why?

    PubMed Central

    Govindarajan, S.; Sharath, B. N.; Tripathy, J. P.; Chinnakali, P.; Kumar, A. M. V.; Muthaiah, M.; Vivekananda, K.; Paulraj, A. K.; Roy, G.

    2015-01-01

    Setting: The Revised National Tuberculosis Control Programme, Puducherry, India, which has facilities for molecular diagnostic technique. Objective: To determine pre-diagnostic and pre-treatment attrition among presumptive multidrug-resistant tuberculosis (MDR-TB) patients and reasons for attrition. Methods: In this mixed-methods study, the quantitative component consisted of retrospective cohort analysis through record review of all presumptive MDR-TB patients recorded between October 2012 and September 2013. The qualitative component included in-depth interviews with key informants involved in programmatic management of drug-resistant tuberculosis services. Results: Of 341 eligible presumptive MDR-TB patients, pre-diagnostic and pre-treatment attrition was respectively 45.5% (155/341) and 29% (2/7). Patients with extra-pulmonary TB (RR = 2.3), those with human immuno-deficiency and TB co-infection (RR = 1.7), those registered during October–December 2012 (RR = 1.3) and those identified from primary/secondary health centres (RR = 1.8) were less likely to be tested. Themes that emerged during the analysis of the qualitative data were ‘lack of a systematic mechanism to track referrals for culture and drug susceptibility testing’, ‘absence of courier service to transport sputum’, ‘lack of knowledge and ownership among staff of general health system’, ‘shortage of diagnostic kits’ and ‘patient non-adherence’. Conclusion: Despite the introduction of molecular diagnostic techniques, operational issues in MDR-TB screening remain a concern and require urgent attention. PMID:26400385

  12. Benefits and drawbacks of molecular techniques for diagnosis of viral respiratory infections. Experience with two multiplex PCR assays.

    PubMed

    García-Arroyo, Laura; Prim, Núria; Martí, Neus; Roig, Maria Carme; Navarro, Ferran; Rabella, Núria

    2016-01-01

    Molecular techniques have represented a major step forward in the diagnosis of viral respiratory infections. They are considered highly sensitive and specific compared to conventional techniques. In this study two nucleic acid amplification tests (NAATs) were compared to conventional methods (immunofluorescence and viral culture). The aim of this work was to discuss the clinical interpretation of the results obtained by NAATs on the basis of the two-decade experience of our group and the literature. Eighty nasopharyngeal aspirates were collected from children under six years attended for acute respiratory illness at the pediatric emergency room of a third level Hospital. Both NAATs tested (Seeplex(®) and Clart(®) ) showed an overall higher performance regarding sensitivity (76% and 90%, respectively). Compared to Seeplex(®) , the Clart(®) system tripled the number of multiple detections (8 by Seeplex(®) vs. 25 by Clart(®) ). In some specimens both NAATs detected different viruses. Given these discrepancies and the fact that detection of viral nucleic acids is not necessarily related to the current clinical syndrome, the interpretation of molecular results may not always be so straightforward. The pros and cons of NAATs should always be taken into account when giving a result. J. Med. Virol. 88:45-50, 2016. © 2015 Wiley Periodicals, Inc. PMID:26100363

  13. PREFACE: Exploring surfaces and buried interfaces of functional materials by advanced x-ray and neutron techniques Exploring surfaces and buried interfaces of functional materials by advanced x-ray and neutron techniques

    NASA Astrophysics Data System (ADS)

    Sakurai, Kenji

    2010-12-01

    This special issue is devoted to describing recent applications of x-ray and neutron scattering techniques to the exploration of surfaces and buried interfaces of various functional materials. Unlike many other surface-sensitive methods, these techniques do not require ultra high vacuum, and therefore, a variety of real and complicated surfaces fall within the scope of analysis. It must be particularly emphasized that the techniques are capable of seeing even buried function interfaces as well as the surface. Furthermore, the information, which ranges from the atomic to mesoscopic scale, is highly quantitative and reproducible. The non-destructive nature of the techniques is another important advantage of using x-rays and neutrons, when compared with other atomic-scale analyses. This ensures that the same specimen can be measured by other techniques. Such features are fairly attractive when exploring multilayered materials with nanostructures (dots, tubes, wires, etc), which are finding applications in electronic, magnetic, optical and other devices. The Japan Applied Physics Society has established a group to develop the research field of studying buried function interfaces with x-rays and neutrons. As the methods can be applied to almost all types of materials, from semiconductor and electronic devices to soft materials, participants have fairly different backgrounds but share a common interest in state-of-the-art x-ray and neutron techniques and sophisticated applications. A series of workshops has been organized almost every year since 2001. Some international interactions have been continued intensively, although the community is part of a Japanese society. This special issue does not report the proceedings of the recent workshop, although all the authors are in some way involved in the activities of the above society. Initially, we intended to collect quite long overview papers, including the authors' latest and most important original results, as well as updates on recent progress and global trends in the field. We planned to cover quite a wide area of surface and buried interface science with x-rays and neutrons. Following a great deal of discussion during the editing process, we have decided to change direction. As we intend to publish similar special issues on a frequent basis, we will not insist on editing this issue as systematic and complete collections of research. Many authors decided to write an ordinary research paper rather than an article including systematic accounts. Due to this change in policy, some authors declined to contribute, and the number of papers is now just 12. However, readers will find that the special issue gives an interesting collection of new original research in surface and buried interface studies with x-rays and neutrons. The 12 papers cover the following research topics: (1) polymer analysis by diffuse scattering; (2) discussion of the electrochemical solid--liquid interface by synchrotron x-ray diffraction; (3) analysis of capped nanodots by grazing incidence small-angle x-ray scattering (GISAXS); (4) discussion of the strain distribution in silicon by high-resolution x-ray diffraction; (5) study of mesoporous structures by a combination of x-ray reflectivity and GISAXS; (6) discussion of energy-dispersive x-ray reflectometry and its applications; (7) neutron reflectivity studies on hydrogen terminated silicon interface; (8) the fabrication and performance of a special mirror for water windows; (9) depth selective analysis by total-reflection x-ray diffraction; (10) nanoparticle thin films prepared by a gas deposition technique; (11) discussion of crystal truncation rod (CTR) scattering of semiconductor nanostructures; (12) magnetic structure analysis of thin films by polarized neutron reflectivity. While not discussed in the present special issue, x-ray and neutron techniques have made great progress. The most important steps forward have been in 2D/3D real-space imaging, and realtime measurement. Advances in such technologies are bringing with them new opportunities in surfac

  14. Micropen direct-write technique for fabrication of advanced electroceramic and optical materials

    NASA Astrophysics Data System (ADS)

    Sun, Jingjing

    Direct-write technologies, a subset of the rapid prototyping, have been applied for many applications including electronics, photonics and biomedical engineering. Among them, Micropen(TM) is a promising technique, providing precision deposition of materials with various viscosities, on-line design changes and writing on nonplanar substrates. The objective of this project was to directly write two- and three-dimensional novel structures by Micropen(TM) for potential optical and transducer applications. First, to gain a basic understanding of Micropen(TM) operation, poly(methyl methacrylate) (PMMA) solutions were developed as a model system. The effects of solution rheological properties on deposition conditions were investigated. Secondly, PMMA/SiO2 hybrids were developed using sol-gel process. The effects of organic/inorganic ratios on thermal stability, microstructure and optical properties were studied. The solution with 80 wt% PMMA loading was chosen to deposit lines for optical applications. Another application was the direct-write of lead zirconate titanate (PZT) thick films (6-70 mum) for MEMS or high frequency medical imaging applications. Pastes consisting of 15-30 vol% ceramic loading in a sol-gel solution were prepared for the deposition of films on various substrates. The PZT sol was used as a binder as well as to achieve low temperature heat treatment of the films. Using the 15 vol% paste with a 250-mum pen tip, a four-layer film was deposited on a silicon substrate. This 16-mum film with 1 cm 2 area had K of 870, tandelta of 4.1%, Pr of 12.2 muC/cm 2 and Ec of 27 kV/cm. Furthermore, Micropen(TM) was utilized for the direct-write of ceramic skeletal structures to develop PZT ceramic/polymer composites with 2-2 connectivity for medical ultrasound transducers. Ceramic/binder based pastes were developed as writing materials. The 35 vol% paste exhibited shear thinning with a viscosity of 45 Pa?s at lower shear rate and 3 Pa?s at higher shear rate. Using a 100-mum pen tip, the fabricated composite with ˜360 mum height had resonance frequencies of ˜4 MHz, and electromechanical properties of K=650, tandelta=2.1%, kt=0.60 and d33=210 pC/N. Finally, composites with linear and Gaussian volume fraction gradients were fabricated by Micropen(TM). Their vibration amplitude profiles showed maximum output at center with gradual decreasing towards edge of the composites.

  15. Advanced Techniques for Assessment of Postural and Locomotor Ataxia, Spatial Orientation, and Gaze Stability

    NASA Technical Reports Server (NTRS)

    Wall, Conrad., III

    1999-01-01

    In addition to adapting to microgravity, major neurovestibular problems of space flight include postflight difficulties with standing, walking, turning corners, and other activities that require stable upright posture and gaze stability. These difficulties inhibit astronauts' ability to stand or escape from their vehicle during emergencies. The long-ter7n goal of the NSBRI is the development of countermeasures to ameliorate the effects of long duration space flight. These countermeasures must be tested with valid and reliable tools. This project aims to develop quantitative, parametric approaches for assessing gaze stability and spatial orientation during normal gait and when gait is perturbed. Two of this year's most important findings concern head fixation distance and ideal trajectory analysis. During a normal cycle of walking the head moves up and down linearly. A simultaneous angular pitching motion of the head keeps it aligned toward an imaginary point in space at a distance of about one meter in front of a subject and along the line of march. This distance is called the head fixation distance. Head fixation distance provides the fundamental framework necessary for understanding the functional significance of the vestibular reflexes that couple head motion to eye motion. This framework facilitates the intelligent design of counter-measures for the effects of exposure to microgravity upon the vestibular ocular reflexes. Ideal trajectory analysis is a simple candidate countermeasure based upon quantifying body sway during repeated up and down stair stepping. It provides one number that estimates the body sway deviation from an ideal sinusoidal body sway trajectory normalized on the subject's height. This concept has been developed with NSBRI funding in less than one year. These findings are explained in more detail below. Compared to assessments of the vestibuo-ocular reflex, analysis of vestibular effects on locomotor function is relatively less well developed and quantified. We are improving this situation by applying methodologies such as nonlinear orbital stability to quantify responses and by using multivariate statistical approaches to link together the responses across separate tests. In this way we can exploit the information available and increase the ability to discriminate between normal and pathological responses. Measures of stability and orientation are compared to measures such as dynamic visual acuity and with balance function tests. The responses of normal human subjects and of patients having well documented pathophysiologies are being characterized. When these studies are completed, we should have a clearer idea about normal and abnormal patterns of eye, head, and body movements during locomotion and their stability in a wide range of environments. We plan eventually to use this information to validate the efficacy of candidate neurovestibular and neuromuscular rehabilitative techniques. Some representative studies made during this year are summarized.

  16. Secondary sentinel lymph node tracing technique: a new method for tracing lymph nodes in radical gastrectomy for advanced gastric cancer*

    PubMed Central

    LI, Zong-lin; JIANG, Huai-wu; SONG, Min; XU, Liang; XIA, Dong; LIU, Qing

    2015-01-01

    Objective: To explore the feasibility and clinical value of secondary sentinel lymph node (SSLN) tracing technique in radical gastrectomy for advanced gastric cancer (AGC). Methods: From January 2009 to June 2011, 247 patients who suffered from gastric angle cancer with metastasis in No. 3 group lymph nodes were divided randomly into groups A and B. Methylthioninium chloride was injected into the peripheral tissue of the metastatic No. 3 group lymph nodes of 138 patients in group A before tumor resections. SSLNs were traced and individual lymphadenectomies were carried out based on the biopsy results of the SSLNs. Standard D2 radical gastrectomies were carried out directly on 109 patients in group B. Postoperative follow-up and survival analysis were carried out for patients in both groups. Results: SSLNs were found in 114 (82.6%) patients in group A. Ninety of those patients (78.9%) demonstrated existing metastasis in SSLNs. According to Kaplan-Meier’s method, the postoperative 3-year cumulative survival rates were 63.5% and 47.5%, and the median survival time were 40 and 36 months for the patients of groups A and B, respectively (P<0.05). Conclusions: The SSLN tracing technique is feasible in radical gastrectomy for AGC. It gives surgeons important information about the terminal status of lymph node metastasis and provides some scientific basis for individual lymphadenectomy. PMID:26537207

  17. A joint numerical and experimental study of the jet of an aircraft engine installation with advanced techniques

    NASA Astrophysics Data System (ADS)

    Brunet, V.; Molton, P.; Bézard, H.; Deck, S.; Jacquin, L.

    2012-01-01

    This paper describes the results obtained during the European Union JEDI (JEt Development Investigations) project carried out in cooperation between ONERA and Airbus. The aim of these studies was first to acquire a complete database of a modern-type engine jet installation set under a wall-to-wall swept wing in various transonic flow conditions. Interactions between the engine jet, the pylon, and the wing were studied thanks to ¤advanced¥ measurement techniques. In parallel, accurate Reynolds-averaged Navier Stokes (RANS) simulations were carried out from simple ones with the Spalart Allmaras model to more complex ones like the DRSM-SSG (Differential Reynolds Stress Modef of Speziale Sarkar Gatski) turbulence model. In the end, Zonal-Detached Eddy Simulations (Z-DES) were also performed to compare different simulation techniques. All numerical results are accurately validated thanks to the experimental database acquired in parallel. This complete and complex study of modern civil aircraft engine installation allowed many upgrades in understanding and simulation methods to be obtained. Furthermore, a setup for engine jet installation studies has been validated for possible future works in the S3Ch transonic research wind-tunnel. The main conclusions are summed up in this paper.

  18. Advanced Aromatic Polymers with Excellent Antiatomic Oxygen Performance Derived from Molecular Precursor Strategy and Copolymerization of Polyhedral Oligomeric Silsesquioxane.

    PubMed

    Wang, Pei; Tang, Yusheng; Yu, Zhen; Gu, Junwei; Kong, Jie

    2015-09-16

    In this contribution, the advanced aromatic polymers with excellent antiatomic oxygen (AO) performance were designed and synthesized using molecular precursor strategy and copolymerization of polyhedral oligomeric silsesquioxane (POSS). A soluble poly(p-phenylene benzobisoxazole) (PBO) precursor, that is, TBS-PBO (tert-butyldimethylsilyl was denoted as TBS), was designed to overcome the poor solubility of PBO in organic solvents. Then the new copolymer of TBS-PBO-POSS was synthesized by the copolymerization of TBS-PBO and POSS, which possessed good solubility and film-forming ability in common organic solvents, such as N-methylpyrrolidone, N,N-dimethylacetamide, and dimethyl sulfoxide. More importantly, the TBS-PBO-POSS films exhibited outstanding antiatomic oxygen properties because of the incorporation of POSS monomers with cagelike structure into the main chain of copolymer, which drastically reduced the AO-induced erosion owing to the formation of the passivating silica layer on the surface of polymers. When the TBS-PBO-POSS films were exposed to AO effective fluences of 1.5495 × 10(20) atom cm(-2) (5 h) and 4.6486 × 10(20) atom cm(-2) (15 h), the relative mass loss was merely 0.19% and 0.41%, respectively. This work provides a new perspective and efficient strategy for the molecular design of aromatic heterocyclic polymers possessing excellent combination properties including processing convenience and antioxidative and mechanical properties, which can be employed as potential candidates to endure the aggressive environment encountered in low earth orbits. PMID:26322523

  19. Asymptomatic bacteriuria: prevalence rates of causal microorganisms, etiology of infection in different patient populations, and recent advances in molecular detection.

    PubMed

    Ipe, Deepak S; Sundac, Lana; Benjamin, William H; Moore, Kate H; Ulett, Glen C

    2013-09-01

    Bacteriuria, or the presence of bacteria in urine, is associated with both asymptomatic and symptomatic urinary tract infection and underpins much of the dynamic of microbial colonization of the urinary tract. The prevalence of bacteriuria in dissimilar patient groups such as healthy adults, institutionalized elderly, pregnant women, and immune-compromised patients varies widely. In addition, assessing the importance of 'significant bacteriuria' in infected individuals represents a diagnostic challenge, partly due to various causal microorganisms, and requires careful consideration of the distinct etiologies of bacteriuria in different populations and circumstances. Recent molecular discoveries have revealed how some bacterial traits can enable organisms to grow in human urine, which, as a fitness adaptation, is likely to influence the progression of bacteriuria in some individuals. In this review, we comprehensively analyze currently available data on the prevalence of causal organisms with a focus on asymptomatic bacteriuria in dissimilar populations. We evaluate recent advances in the molecular detection of bacteriuria from a diagnostic viewpoint and briefly discuss the potential benefits and some of the challenges of these approaches. Overall, this review provides an update on the comparative prevalence and etiology of bacteriuria from both microbiological and clinical perspectives. PMID:23808987

  20. AGRO/HORT/BOTA 339: Introduction to the molecular techniques of

    E-print Network

    Emshwiller, Eve

    : 348 Plant Sciences Lab: 219 Plant Sciences Email: jane@wisc.edu Email: djayaraman@wisc.edu Phone: 262-6457 Phone: 890-0155 OFFICE HOURS MF 1:30-2:30 and by appointment SCHEDULE LEC 11am-12:15 pm TR 136 Plant LEC Sept 20: The basics of cloning LAB Sept 19 or 20: Basic bacterial culture techniques (growth

  1. Moving from histological subtyping to molecular characterization: new treatment opportunities in advanced non-small-cell lung cancer.

    PubMed

    Carnio, Simona; Novello, Silvia; Bironzo, Paolo; Scagliotti, Giorgio Vittorio

    2014-12-01

    Over the last 10 years, the systemic treatment of advanced non-small-cell lung cancer has progressively moved away from the 'one-size-fits-all' approach to histological subtyping. Currently, there is a progressive implementation of targeted therapies based on specific molecular characteristics such as the EGF receptor sensitizing mutations and the anaplastic lymphoma kinase rearrangements. Despite the availability of effective agents against these abnormalities, acquired resistance is still a major issue. A new generation of tyrosine kinase inhibitors for EGF receptor and anaplastic lymphoma kinase targeting acquired resistance mechanisms have been recently investigated. Several promising tyrosine kinase inhibitors that hit other targets are also in clinical development, including: rat sarcoma gene/MEK, BRAF1, PIK3A, c-mesenchymal-epithelial transition, c-ros oncogene 1, rearranged during transfection, human EGFR 2, FGFR, VEGFR, PDGFR and discoidin death receptor 2. Furthermore, new advances in immunology have been achieved through the discovery of vaccines and immune checkpoint pathways such as the cytotoxic T-lymphocyte-associated antigen-4, programmed cell death protein 1 and its ligands. PMID:25183305

  2. Novel genotype-phenotype associations in human cancers enabled by advanced molecular platforms and computational analysis of whole slide images

    PubMed Central

    Cooper, Lee A.D.; Kong, Jun; Gutman, David A.; Dunn, William D.; Nalisnik, Michael; Brat, Daniel J.

    2014-01-01

    Technological advances in computing, imaging and genomics have created new opportunities for exploring relationships between histology, molecular events and clinical outcomes using quantitative methods. Slide scanning devices are now capable of rapidly producing massive digital image archives that capture histological details in high-resolution. Commensurate advances in computing and image analysis algorithms enable mining of archives to extract descriptions of histology, ranging from basic human annotations to automatic and precisely quantitative morphometric characterization of hundreds of millions of cells. These imaging capabilities represent a new dimension in tissue-based studies, and when combined with genomic and clinical endpoints, can be used to explore biologic characteristics of the tumor microenvironment and to discover new morphologic biomarkers of genetic alterations and patient outcomes. In this paper we review developments in quantitative imaging technology and illustrate how image features can be integrated with clinical and genomic data to investigate fundamental problems in cancer. Using motivating examples from the study of glioblastomas (GBMs), we demonstrate how public data from The Cancer Genome Atlas (TCGA) can serve as an open platform to conduct in silico tissue based studies that integrate existing data resources. We show how these approaches can be used to explore the relation of the tumor microenvironment to genomic alterations and gene expression patterns and to define nuclear morphometric features that are predictive of genetic alterations and clinical outcomes. Challenges, limitations and emerging opportunities in the area of quantitative imaging and integrative analyses are also discussed. PMID:25599536

  3. In vivo molecular imaging of chemokine receptor CXCR4 expression in patients with advanced multiple myeloma

    PubMed Central

    Philipp-Abbrederis, Kathrin; Herrmann, Ken; Knop, Stefan; Schottelius, Margret; Eiber, Matthias; Lückerath, Katharina; Pietschmann, Elke; Habringer, Stefan; Gerngroß, Carlos; Franke, Katharina; Rudelius, Martina; Schirbel, Andreas; Lapa, Constantin; Schwamborn, Kristina; Steidle, Sabine; Hartmann, Elena; Rosenwald, Andreas; Kropf, Saskia; Beer, Ambros J; Peschel, Christian; Einsele, Hermann; Buck, Andreas K; Schwaiger, Markus; Götze, Katharina; Wester, Hans-Jürgen; Keller, Ulrich

    2015-01-01

    CXCR4 is a G-protein-coupled receptor that mediates recruitment of blood cells toward its ligand SDF-1. In cancer, high CXCR4 expression is frequently associated with tumor dissemination and poor prognosis. We evaluated the novel CXCR4 probe [68Ga]Pentixafor for in vivo mapping of CXCR4 expression density in mice xenografted with human CXCR4-positive MM cell lines and patients with advanced MM by means of positron emission tomography (PET). [68Ga]Pentixafor PET provided images with excellent specificity and contrast. In 10 of 14 patients with advanced MM [68Ga]Pentixafor PET/CT scans revealed MM manifestations, whereas only nine of 14 standard [18F]fluorodeoxyglucose PET/CT scans were rated visually positive. Assessment of blood counts and standard CD34+ flow cytometry did not reveal significant blood count changes associated with tracer application. Based on these highly encouraging data on clinical PET imaging of CXCR4 expression in a cohort of MM patients, we conclude that [68Ga]Pentixafor PET opens a broad field for clinical investigations on CXCR4 expression and for CXCR4-directed therapeutic approaches in MM and other diseases. PMID:25736399

  4. Continuous distribution model for the investigation of complex molecular architectures near interfaces with scattering techniques

    NASA Astrophysics Data System (ADS)

    Shekhar, Prabhanshu; Nanda, Hirsh; Lösche, Mathias; Heinrich, Frank

    2011-11-01

    Biological membranes are composed of a thermally disordered lipid matrix and therefore require non-crystallographic scattering approaches for structural characterization with x-rays or neutrons. Here we develop a continuous distribution (CD) model to refine neutron or x-ray reflectivity data from complex architectures of organic molecules. The new model is a flexible implementation of the composition-space refinement of interfacial structures to constrain the resulting scattering length density profiles. We show this model increases the precision with which molecular components may be localized within a sample, with a minimal use of free model parameters. We validate the new model by parameterizing all-atom molecular dynamics (MD) simulations of bilayers and by evaluating the neutron reflectivity of a phospholipid bilayer physisorbed to a solid support. The determination of the structural arrangement of a sparsely-tethered bilayer lipid membrane (stBLM) comprised of a multi-component phospholipid bilayer anchored to a gold substrate by a thiolated oligo(ethylene oxide) linker is also demonstrated. From the model we extract the bilayer composition and density of tether points, information which was previously inaccessible for stBLM systems. The new modeling strategy has been implemented into the ga_refl reflectivity data evaluation suite, available through the National Institute of Standards and Technology (NIST) Center for Neutron Research (NCNR).

  5. Continuous distribution model for the investigation of complex molecular architectures near interfaces with scattering techniques

    SciTech Connect

    Shekhar, Prabhanshu; Nanda, Hirsh; Heinrich, Frank; Loesche, Mathias

    2011-11-15

    Biological membranes are composed of a thermally disordered lipid matrix and therefore require non-crystallographic scattering approaches for structural characterization with x-rays or neutrons. Here we develop a continuous distribution (CD) model to refine neutron or x-ray reflectivity data from complex architectures of organic molecules. The new model is a flexible implementation of the composition-space refinement of interfacial structures to constrain the resulting scattering length density profiles. We show this model increases the precision with which molecular components may be localized within a sample, with a minimal use of free model parameters. We validate the new model by parameterizing all-atom molecular dynamics (MD) simulations of bilayers and by evaluating the neutron reflectivity of a phospholipid bilayer physisorbed to a solid support. The determination of the structural arrangement of a sparsely-tethered bilayer lipid membrane (stBLM) comprised of a multi-component phospholipid bilayer anchored to a gold substrate by a thiolated oligo(ethylene oxide) linker is also demonstrated. From the model we extract the bilayer composition and density of tether points, information which was previously inaccessible for stBLM systems. The new modeling strategy has been implemented into the ga lowbar refl reflectivity data evaluation suite, available through the National Institute of Standards and Technology (NIST) Center for Neutron Research (NCNR).

  6. Measurement of surface stay times for physical adsorption of gases. Ph.D. Thesis - Va. Univ.; [using molecular beam time of flight technique

    NASA Technical Reports Server (NTRS)

    Wilmoth, R. G.

    1973-01-01

    A molecular beam time-of-flight technique is studied as a means of determining surface stay times for physical adsorption. The experimental approach consists of pulsing a molecular beam, allowing the pulse to strike an adsorbing surface and detecting the molecular pulse after it has subsequently desorbed. The technique is also found to be useful for general studies of adsorption under nonequilibrium conditions including the study of adsorbate-adsorbate interactions. The shape of the detected pulse is analyzed in detail for a first-order desorption process. For mean stay times, tau, less than the mean molecular transit times involved, the peak of the detected pulse is delayed by an amount approximately equal to tau. For tau much greater than these transit times, the detected pulse should decay as exp(-t/tau). However, for stay times of the order of the transit times, both the molecular speed distributions and the incident pulse duration time must be taken into account.

  7. Current Advances in the Application of Raman Spectroscopy for Molecular Diagnosis of Cervical Cancer

    PubMed Central

    Ramos, Inês Raquel Martins; Malkin, Alison; Lyng, Fiona Mary

    2015-01-01

    Raman spectroscopy provides a unique biochemical fingerprint capable of identifying and characterizing the structure of molecules, cells, and tissues. In cervical cancer, it is acknowledged as a promising biochemical tool due to its ability to detect premalignancy and early malignancy stages. This review summarizes the key research in the area and the evidence compiled is very encouraging for ongoing and further research. In addition to the diagnostic potential, promising results for HPV detection and monitoring treatment response suggest more than just a diagnosis prospective. A greater body of evidence is however necessary before Raman spectroscopy is fully validated for clinical use and larger comprehensive studies are required to fully establish the role of Raman spectroscopy in the molecular diagnostics of cervical cancer. PMID:26180802

  8. New advances in molecular mechanisms and emerging therapeutic targets in alcoholic liver diseases

    PubMed Central

    Williams, Jessica A; Manley, Sharon; Ding, Wen-Xing

    2014-01-01

    Alcoholic liver disease is a major health problem in the United States and worldwide. Chronic alcohol consumption can cause steatosis, inflammation, fibrosis, cirrhosis and even liver cancer. Significant progress has been made to understand key events and molecular players for the onset and progression of alcoholic liver disease from both experimental and clinical alcohol studies. No successful treatments are currently available for treating alcoholic liver disease; therefore, development of novel pathophysiological-targeted therapies is urgently needed. This review summarizes the recent progress on animal models used to study alcoholic liver disease and the detrimental factors that contribute to alcoholic liver disease pathogenesis including miRNAs, S-adenosylmethionine, Zinc deficiency, cytosolic lipin-1?, IRF3-mediated apoptosis, RIP3-mediated necrosis and hepcidin. In addition, we summarize emerging adaptive protective effects induced by alcohol to attenuate alcohol-induced liver pathogenesis including FoxO3, IL-22, autophagy and nuclear lipin-1?. PMID:25278688

  9. Biosynthesis, structural architecture and biotechnological potential of bacterial tannase: a molecular advancement.

    PubMed

    Jana, Arijit; Halder, Suman Kumar; Banerjee, Amrita; Paul, Tanmay; Pati, Bikash Ranjan; Mondal, Keshab Chandra; Das Mohapatra, Pradeep Kumar

    2014-04-01

    Tannin-rich materials are abundantly generated as wastes from several agroindustrial activities. Therefore, tannase is an interesting hydrolase, for bioconversion of tannin-rich materials into value added products by catalyzing the hydrolysis of ester and depside bonds and unlocked a new prospect in different industrial sectors like food, beverages, pharmaceuticals, etc. Microorganisms, particularly bacteria are one of the major sources of tannase. In the last decade, cloning and heterologous expression of novel tannase genes and structural study has gained momentum. In this article, we have emphasized critically on bacterial tannase that have gained worldwide research interest for their diverse properties. The present paper delineate the developments that have taken place in understanding the role of tannase action, microbial sources, various cultivation aspects, downstream processing, salient biochemical properties, structure and active sites, immobilization, efforts in cloning and overexpression and with special emphasis on recent molecular and biotechnological achievements. PMID:24613317

  10. Recent advances in Employing Molecular Modelling to Determine the Specificity of Glycan-Binding Proteins

    PubMed Central

    Grant, Oliver C.; Woods, Robert J.

    2014-01-01

    Impressive improvements in docking performance can be achieved by applying energy bonuses to poses in which glycan hydroxyl groups occupy positions otherwise preferred by bound waters. In addition, inclusion of glycosidic conformational energies allows unlikely glycan conformations to be appropriately penalized. A method for predicting the binding specificity of glycan-binding proteins has been developed, which is based on grafting glycan branches onto a minimal binding determinant in the binding site. Grafting can be used either to screen virtual libraries of glycans, such as the known glycome, or to identify docked poses of minimal binding determinants that are consistent with specificity data. The reviewed advances allow accurate modelling of carbohydrate-protein 3D co-complexes, but challenges remain in ranking the affinity of congeners. PMID:25108191

  11. Advances in understanding the molecular basis of the first steps in color vision.

    PubMed

    Hofmann, Lukas; Palczewski, Krzysztof

    2015-11-01

    Serving as one of our primary environmental inputs, vision is the most sophisticated sensory system in humans. Here, we present recent findings derived from energetics, genetics and physiology that provide a more advanced understanding of color perception in mammals. Energetics of cis-trans isomerization of 11-cis-retinal accounts for color perception in the narrow region of the electromagnetic spectrum and how human eyes can absorb light in the near infrared (IR) range. Structural homology models of visual pigments reveal complex interactions of the protein moieties with the light sensitive chromophore 11-cis-retinal and that certain color blinding mutations impair secondary structural elements of these G protein-coupled receptors (GPCRs). Finally, we identify unsolved critical aspects of color tuning that require future investigation. PMID:26187035

  12. Advances in understanding the molecular basis of the first steps in color vision

    PubMed Central

    Hofmann, Lukas; Palczewski, Krzysztof

    2015-01-01

    Serving as one of our primary environmental inputs, vision is the most sophisticated sensory system in humans. Here, we present recent findings derived from energetics, genetics and physiology that provide a more advanced understanding of color perception in mammals. Energetics of cis–trans isomerization of 11-cis-retinal accounts for color perception in the narrow region of the electromagnetic spectrum and how human eyes can absorb light in the near infrared (IR) range. Structural homology models of visual pigments reveal complex interactions of the protein moieties with the light sensitive chromophore 11-cis-retinal and that certain color blinding mutations impair secondary structural elements of these G protein-coupled receptors (GPCRs). Finally, we identify unsolved critical aspects of color tuning that require future investigation. PMID:26187035

  13. Molecular imaging with radionuclides, a powerful technique for studying biological processes in vivo

    NASA Astrophysics Data System (ADS)

    Cisbani, E.; Cusanno, F.; Garibaldi, F.; Magliozzi, M. L.; Majewski, S.; Torrioli, S.; Tsui, B. M. W.

    2007-02-01

    Our team is carrying on a systematic study devoted to the design of a SPECT detector with submillimeter resolution and adequate sensitivity (1 cps/kBq). Such system will be used for functional imaging of biological processes at molecular level in small animal. The system requirements have been defined by two relevant applications: study of atherosclerotic plaques characterization and stem cells diffusion and homing. In order to minimize costs and implementation time, the gamma detector will be based—as much as possible—on conventional components: scintillator crystal and position sensitive PhotoMultipliers read by individual channel electronics. A coded aperture collimator should be adapted to maximize the efficiency. The optimal selection of the detector components is investigated by systematic use of Monte-Carlo simulations (and laboratory validation tests); and finally preliminary results are presented and discussed here.

  14. POC-scale testing of an advanced fine coal dewatering equipment/technique. Quarterly technical progress report 6, January--March 1996

    SciTech Connect

    Tao, D.; Groppo, J.G.; Parekh, B.K.

    1996-05-03

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine clean coal. Economical dewatering of an ultra-fine clean coal product to a 20% level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20% or lower moisture using either conventional or advanced dewatering techniques. The cost-sharing contract effort is for 36 months beginning September 30, 1994. This report discusses technical progress made during the quarter from January 1- March 31, 1996.

  15. Advances in molecular-based personalized non-small-cell lung cancer therapy: targeting epidermal growth factor receptor and mechanisms of resistance

    PubMed Central

    Jotte, Robert M; Spigel, David R

    2015-01-01

    Molecularly targeted therapies, directed against the features of a given tumor, have allowed for a personalized approach to the treatment of advanced non-small-cell lung cancer (NSCLC). The reversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib had undergone turbulent clinical development until it was discovered that these agents have preferential activity in patients with NSCLC harboring activating EGFR mutations. Since then, a number of phase 3 clinical trials have collectively shown that EGFR-TKI monotherapy is more effective than combination chemotherapy as first-line therapy for EGFR mutation-positive advanced NSCLC. The next generation of EGFR-directed agents for EGFR mutation-positive advanced NSCLC is irreversible TKIs against EGFR and other ErbB family members, including afatinib, which was recently approved, and dacomitinib, which is currently being tested in phase 3 trials. As research efforts continue to explore the various proposed mechanisms of acquired resistance to EGFR-TKI therapy, agents that target signaling pathways downstream of EGFR are being studied in combination with EGFR TKIs in molecularly selected advanced NSCLC. Overall, the results of numerous ongoing phase 3 trials involving the EGFR TKIs will be instrumental in determining whether further gains in personalized therapy for advanced NSCLC are attainable with newer agents and combinations. This article reviews key clinical trial data for personalized NSCLC therapy with agents that target the EGFR and related pathways, specifically based on molecular characteristics of individual tumors, and mechanisms of resistance. PMID:26310719

  16. Identification and assessment of genetic similarity of soil bacterial isolates of Pseudomonas spp. using molecular techniques.

    PubMed

    Lisek, Anna; Sas Paszt, Lidia; Trzci?ski, Pawe?

    2014-01-01

    Bacteria of the genus Pseudomonas are often components of bioproducts designed to enhance the condition of the soil and plants. The use of Pseudomonas bacteria in bioproducts must be preceded by the acquisition, characterization and selection of beneficial strains living in the soil. A prerequisite for the selection of bacterial strains for use in bioproducts is to be able to identify the isolates rapidly and accurately. To identify and differentiate 15 bacterial isolates obtained from the soil surrounding the roots of sour cherry trees and to assess their genetic similarity, the rep-PCR technique and restriction analysis of the 16S rRNA gene and the 16S-ITS-23S rRNA operon were used. In addition, a sequence analysis of the 16S rRNA gene was performed. The analyses made it possible to divide the isolates into four clusters and to confirm their affiliation with the Pseudomonas species. RFLP analysis of the 16S-ITS-23S rRNA operon enabled greater differentiation of the isolates than RFLP of the 16S rRNA gene. The greatest differentiation of isolates within the clusters was obtained after using the rep-PCR technique. However, none of the techniques was able to discriminate all the isolates, which indicates very high genetic similarity of the Pseudomonas isolates found in the same sample of soil from around the roots of sour cherry trees. The tests performed will find application for distinguishing and identifying Pseudomonas strains collected from the soil in order to select the most valuable bacterial strains that produce beneficial effects on plants. PMID:25546939

  17. Recent advance in molecular angiogenesis in glioblastoma: the challenge and hope for anti-angiogenic therapy.

    PubMed

    Zhang, Meng; Ye, Gengfan; Li, Jianyi; Wang, Yunyan

    2015-10-01

    Glioblastoma (GBM) is the most highly malignant brain tumor in the human central nerve system. In this paper, we review new and significant molecular findings on angiogenesis and possible resistance mechanisms. Expression of a number of genes and regulators has been shown to be upregulated in GBM microvessel cells, such as interleukin-8, signal transducer and activator of transcription 3, Tax-interacting protein-1, hypoxia induced factor-1 and anterior gradient protein 2. The regulator factors that may strongly promote angiogenesis by promoting endothelial cell metastasis, changing the microenvironment, enhancing the ability of resistance to anti-angiogenic therapy, and that inhibit angiogenesis are reviewed. Based on the current knowledge, several potential targets and strategies are proposed for better therapeutic outcomes, such as its mRNA interference of DII4-Notch signaling pathway and depletion of b1 integrin expression. We also discuss possible mechanisms underlying the resistance to anti-angiogenesis and future directions and challenges in developing new targeted therapy for GBM. PMID:26437643

  18. Update on Recent Molecular and Genetic Advances in Frontotemporal Lobar Degeneration

    PubMed Central

    Bigio, Eileen H.

    2009-01-01

    Great strides have been made in the last 2 years in the field of frontotemporal lobar degeneration (FTLD), particularly with respect to the genetics and molecular biology of FTLD with ubiquitinated inclusions. It is now clear that most cases of familial FTLD with ubiquitinated inclusions have mutations in the progranulin gene, located on chromosome 17. It is also clear that most ubiquitinated inclusions in FTLD with ubiquitinated inclusions are composed primarily of TAR DNA-binding protein-43. Thus, FTLDs can be separated into 2 major groups (i.e. tauopathies and ubiquitinopathies), and most of the ubiquitinopathies can now be defined as TAR DNA-binding protein-43 proteinopathies. Many of the familial FTLDs are linked to chromosome 17, including both the familial tauopathies and the familial TAR DNA-binding protein-43 proteinopathies with progranulin mutations. This review highlights the neuropathologic features and the most important discoveries of the last 2 years and places these findings into the historical context of FTLD. PMID:18596549

  19. Septic Shock in Advanced Age: Transcriptome Analysis Reveals Altered Molecular Signatures in Neutrophil Granulocytes

    PubMed Central

    Vieira da Silva Pellegrina, Diogo; Severino, Patricia; Vieira Barbeiro, Hermes; Maziero Andreghetto, Flávia; Tadeu Velasco, Irineu; Possolo de Souza, Heraldo; Machado, Marcel Cerqueira César; Reis, Eduardo Moraes; Pinheiro da Silva, Fabiano

    2015-01-01

    Sepsis is one of the highest causes of mortality in hospitalized people and a common complication in both surgical and clinical patients admitted to hospital for non-infectious reasons. Sepsis is especially common in older people and its incidence is likely to increase substantially as a population ages. Despite its increased prevalence and mortality in older people, immune responses in the elderly during septic shock appear similar to that in younger patients. The purpose of this study was to conduct a genome-wide gene expression analysis of circulating neutrophils from old and young septic patients to better understand how aged individuals respond to severe infectious insult. We detected several genes whose expression could be used to differentiate immune responses of the elderly from those of young people, including genes related to oxidative phosphorylation, mitochondrial dysfunction and TGF-? signaling, among others. Our results identify major molecular pathways that are particularly affected in the elderly during sepsis, which might have a pivotal role in worsening clinical outcomes compared with young people with sepsis. PMID:26047321

  20. The FADE mass-stat: A technique for inserting or deleting particles in molecular dynamics simulations

    SciTech Connect

    Borg, Matthew K.; Lockerby, Duncan A.; Reese, Jason M.

    2014-02-21

    The emergence of new applications of molecular dynamics (MD) simulation calls for the development of mass-statting procedures that insert or delete particles on-the-fly. In this paper we present a new mass-stat which we term FADE, because it gradually “fades-in” (inserts) or “fades-out” (deletes) molecules over a short relaxation period within a MD simulation. FADE applies a time-weighted relaxation to the intermolecular pair forces between the inserting/deleting molecule and any neighbouring molecules. The weighting function we propose in this paper is a piece-wise polynomial that can be described entirely by two parameters: the relaxation time scale and the order of the polynomial. FADE inherently conserves overall system momentum independent of the form of the weighting function. We demonstrate various simulations of insertions of atomic argon, polyatomic TIP4P water, polymer strands, and C{sub 60} Buckminsterfullerene molecules. We propose FADE parameters and a maximum density variation per insertion-instance that restricts spurious potential energy changes entering the system within desired tolerances. We also demonstrate in this paper that FADE compares very well to an existing insertion algorithm called USHER, in terms of accuracy, insertion rate (in dense fluids), and computational efficiency. The USHER algorithm is applicable to monatomic and water molecules only, but we demonstrate that FADE can be generally applied to various forms and sizes of molecules, such as polymeric molecules of long aspect ratio, and spherical carbon fullerenes with hollow interiors.

  1. Dispersing perylene diimide/SWCNT hybrids: structural insights at the molecular level and fabricating advanced materials.

    PubMed

    Tsarfati, Yael; Strauss, Volker; Kuhri, Susanne; Krieg, Elisha; Weissman, Haim; Shimoni, Eyal; Baram, Jonathan; Guldi, Dirk M; Rybtchinski, Boris

    2015-06-17

    The unique properties of carbon nanotubes (CNT) are advantageous for emerging applications. Yet, the CNT insolubility hampers their potential. Approaches based on covalent and noncovalent methodologies have been tested to realize stable dispersions of CNTs. Noncovalent approaches are of particular interest as they preserve the CNT's structures and properties. We report on hybrids, in which perylene diimide (PDI) amphiphiles are noncovalently immobilized onto single wall carbon nanotubes (SWCNT). The resulting hybrids were dispersed and exfoliated both in water and organic solvents in the presence of two different PDI derivatives, PP2b and PP3a. The dispersions were investigated using cryogenic transmission electron microscopy (cryo-TEM), providing unique structural insights into the exfoliation. A helical arrangement of PP2b assemblies on SWCNTs dominates in aqueous dispersions, while a single layer of PP2b and PP3a was found on SWCNTs in organic dispersions. The dispersions were probed by steady-state and time-resolved spectroscopies, revealing appreciable charge redistribution in the ground state, and an efficient electron transfer from SWCNTs to PDIs in the excited state. We also fabricated hybrid materials from the PP2b/SWCNT dispersions. A supramolecular membrane was prepared from aqueous dispersions and used for size-selective separation of gold nanoparticles. Hybrid buckypaper films were prepared from the organic dispersions. In the latter, high conductivity results from enhanced electronic communication and favorable morphology within the hybrid material. Our findings shed light onto SWCNT/dispersant molecular interactions, and introduce a versatile approach toward universal solution processing of SWCNT-based materials. PMID:25977989

  2. Bacterial community structure and activity of sulfate reducing bacteria in a membrane aerated biofilm analyzed by microsensor and molecular techniques.

    PubMed

    Liu, Hong; Tan, Shuying; Sheng, Zhiya; Liu, Yang; Yu, Tong

    2014-11-01

    The activities and vertical spatial distribution of sulfate reducing bacteria (SRB) in an oxygen (O2 )-based membrane aerated biofilm (MAB) were investigated using microsensor (O2 and H2 S) measurements and molecular techniques (polymerase chain reaction-denaturing gradient gel electrophoresis [PCR-DGGE] and fluorescence in situ hybridization [FISH]). The O2 concentration profile revealed that O2 penetrated from the bottom (substratum) of the gas permeable membrane, and was gradually consumed within the biofilm until it was completely depleted near the biofilm/bulk liquid interface, indicating oxic and anoxic zone in the MAB. The H2 S concentration profile showed that H2 S production was found in the upper 285?µm of the biofilm, indicating a high activity of SRB in this region. The results from DGGE of the PCR-amplified dissimilatory sulfite reductase subunit B (dsrB) gene and FISH showed an uneven spatial distribution of SRB. The maximum SRB biomass was located in the upper biofilm. The information from the molecular analysis can be supplemented with that from microsensor measurements to better understand the microbial community and activity of SRB in the MAB. PMID:24890472

  3. Evaluation and comparison of molecular techniques for epidemiological typing of Salmonella enterica subsp. enterica serovar dublin.

    PubMed Central

    Liebisch, B; Schwarz, S

    1996-01-01

    A total of 28 unrelated isolates of the Salmonella enterica subsp. enterica serovar dublin (S. dublin) collected during a 6-year period, as well as four samples of the S. dublin live vaccine strain Bovisaloral and its prototype strain S. dublin 442/039, were investigated by different molecular typing methods for the following reasons: (i) to find the most discriminatory method for the epidemiological typing of isolates belonging to this Salmonella serovar and (ii) to evaluate these methods for their capacity to discriminate among the live vaccine strain Bovisaloral, its prototype strain S. dublin 442/039, and field isolates of the serovar dublin. Five different plasmid profiles were observed; a virulence plasmid of 76 kbp as identified by hybridization with an spvB-spvC gene probe was present in all isolates. The detection of 16S rRNA genes and that of IS200 elements proved to be unsuitable for the epidemiological typing of S. dublin; only one hybridization pattern could be observed with each of these methods. The results obtained from macrorestriction analysis strongly depended on the choice of restriction enzyme. While the enzyme NotI yielded the lowest discriminatory index among all enzymes tested, it was the only enzyme that allowed discrimination between the Bovisaloral vaccine strain and its prototype strain. In contrast to the enzymes XbaI and SpeI, which only differentiated among the S. dublin field isolates, XhoI as well as AvrII also produced restriction fragment patterns of the Bovisaloral strain and of its prototype strain that were not shared by any of the S. dublin field isolates. Macrorestriction analysis proved to be the most discriminatory method not only for the epidemiological typing of S. dublin field isolates but also for the identification of the S. dublin live vaccine strain Bovisaloral. PMID:8904430

  4. A Bird’s-Eye View of Molecular Changes in Plant Gravitropism Using Omics Techniques

    PubMed Central

    Schüler, Oliver; Hemmersbach, Ruth; Böhmer, Maik

    2015-01-01

    During evolution, plants have developed mechanisms to adapt to a variety of environmental stresses, including drought, high salinity, changes in carbon dioxide levels and pathogens. Central signaling hubs and pathways that are regulated in response to these stimuli have been identified. In contrast to these well studied environmental stimuli, changes in transcript, protein and metabolite levels in response to a gravitational stimulus are less well understood. Amyloplasts, localized in statocytes of the root tip, in mesophyll cells of coleoptiles and in the elongation zone of the growing internodes comprise statoliths in higher plants. Deviations of the statocytes with respect to the earthly gravity vector lead to a displacement of statoliths relative to the cell due to their inertia and thus to gravity perception. Downstream signaling events, including the conversion from the biophysical signal of sedimentation of distinct heavy mass to a biochemical signal, however, remain elusive. More recently, technical advances, including clinostats, drop towers, parabolic flights, satellites, and the International Space Station, allowed researchers to study the effect of altered gravity conditions – real and simulated micro- as well as hypergravity on plants. This allows for a unique opportunity to study plant responses to a purely anthropogenic stress for which no evolutionary program exists. Furthermore, the requirement for plants as food and oxygen sources during prolonged manned space explorations led to an increased interest in the identi-fication of genes involved in the adaptation of plants to microgravity. Transcriptomic, proteomic, phosphoproteomic, and metabolomic profiling strategies provide a sensitive high-throughput approach to identify biochemical alterations in response to changes with respect to the influence of the gravitational vector and thus the acting gravitational force on the transcript, protein and metabolite level. This review aims at summarizing recent experimental approaches and discusses major observations.

  5. Advanced Cu chemical displacement technique for SiO2-based electrochemical metallization ReRAM application

    PubMed Central

    2014-01-01

    This study investigates an advanced copper (Cu) chemical displacement technique (CDT) with varying the chemical displacement time for fabricating Cu/SiO2-stacked resistive random-access memory (ReRAM). Compared with other Cu deposition methods, this CDT easily controls the interface of the Cu-insulator, the switching layer thickness, and the immunity of the Cu etching process, assisting the 1-transistor-1-ReRAM (1T-1R) structure and system-on-chip integration. The modulated shape of the Cu-SiO2 interface and the thickness of the SiO2 layer obtained by CDT-based Cu deposition on SiO2 were confirmed by scanning electron microscopy and atomic force microscopy. The CDT-fabricated Cu/SiO2-stacked ReRAM exhibited lower operation voltages and more stable data retention characteristics than the control Cu/SiO2-stacked sample. As the Cu CDT processing time increased, the forming and set voltages of the CDT-fabricated Cu/SiO2-stacked ReRAM decreased. Conversely, decreasing the processing time reduced the on-state current and reset voltage while increasing the endurance switching cycle time. Therefore, the switching characteristics were easily modulated by Cu CDT, yielding a high performance electrochemical metallization (ECM)-type ReRAM. PMID:25364318

  6. Advanced Glycation End-Products Reduce Collagen Molecular Sliding to Affect Collagen Fibril Damage Mechanisms but Not Stiffness

    PubMed Central

    Fessel, Gion; Li, Yufei; Diederich, Vincent; Guizar-Sicairos, Manuel; Schneider, Philipp; Sell, David R.; Monnier, Vincent M.; Snedeker, Jess G.

    2014-01-01

    Advanced glycation end-products (AGE) contribute to age-related connective tissue damage and functional deficit. The documented association between AGE formation on collagens and the correlated progressive stiffening of tissues has widely been presumed causative, despite the lack of mechanistic understanding. The present study investigates precisely how AGEs affect mechanical function of the collagen fibril – the supramolecular functional load-bearing unit within most tissues. We employed synchrotron small-angle X-ray scattering (SAXS) and carefully controlled mechanical testing after introducing AGEs in explants of rat-tail tendon using the metabolite methylglyoxal (MGO). Mass spectrometry and collagen fluorescence verified substantial formation of AGEs by the treatment. Associated mechanical changes of the tissue (increased stiffness and failure strength, decreased stress relaxation) were consistent with reports from the literature. SAXS analysis revealed clear changes in molecular deformation within MGO treated fibrils. Underlying the associated increase in tissue strength, we infer from the data that MGO modified collagen fibrils supported higher loads to failure by maintaining an intact quarter-staggered conformation to nearly twice the level of fibril strain in controls. This apparent increase in fibril failure resistance was characterized by reduced side-by-side sliding of collagen molecules within fibrils, reflecting lateral molecular interconnectivity by AGEs. Surprisingly, no change in maximum fibril modulus (2.5 GPa) accompanied the changes in fibril failure behavior, strongly contradicting the widespread assumption that tissue stiffening in ageing and diabetes is directly related to AGE increased fibril stiffness. We conclude that AGEs can alter physiologically relevant failure behavior of collagen fibrils, but that tissue level changes in stiffness likely occur at higher levels of tissue architecture. PMID:25364829

  7. Testing an advanced satellite technique for dust detection as a decision support system for the air quality assessment

    NASA Astrophysics Data System (ADS)

    Falconieri, Alfredo; Filizzola, Carolina; Femiano, Rossella; Marchese, Francesco; Sannazzaro, Filomena; Pergola, Nicola; Tramutoli, Valerio; Di Muro, Ersilia; Divietri, Mariella; Crisci, Anna Maria; Lovallo, Michele; Mangiamele, Lucia; Vaccaro, Maria Pia; Palma, Achille

    2014-05-01

    In order to correctly apply the European directive for air quality (2008/50/CE), local Authorities are often requested to discriminate the possible origin (natural/anthropic) of anomalous concentration of pollutants in the air (art.20 Directive 2008/50/CE). In this framework, it's been focused on PM10 and PM2,5 concentrations and sources. In fact, depending on their origin, appropriate counter-measures can be taken devoted to prevent their production (e.g. by traffic restriction) or simply to reduce their impact on citizen health (e.g. information campaigns). In this context suitable satellite techniques can be used in order to identify natural sources (particularly Saharan dust, but also volcanic ash or forest fire smoke) that can be responsible of over-threshold concentration of PM10/2,5 in populated areas. In the framework of the NIBS (Networking and Internationalization of Basilicata Space Technologies) project, funded by the Basilicata Region within the ERDF 2007-2013 program, the School of Engineering of University of Basilicata, the Institute of Methodologies for Environmental Analysis of National Research Council (IMAA-CNR) and the Regional Agency for the Protection of the Environment of Basilicata Region (ARPAB) have started a collaboration devoted to assess the potential of the use of advanced satellite techniques for Saharan dust events identification to support ARPAB activities related to the application of the European directive for air quality (2008/50/CE) in Basilicata region. In such a joint activity, the Robust Satellite Technique (RST) approach has been assessed and tested as a decision support system for monitoring and evaluating air quality at local and regional level. In particular, RST-DUST products, derived by processing high temporal resolution data provided by SEVIRI (Spinning Enhanced Visible and Infrared Imager) sensor on board Meteosat Second Generation platforms, have been analysed together with PM10 measurements performed by the ground-based stations operated by ARPAB. Such an inter-comparison was devoted to investigate possible PM10 over-threshold occurrences and to better evaluate their possible causes (i.e. anthropogenic and/or natural sources). The analysis demonstrated the added value of an independent, automatic and unsupervised satellite based system (capable of discriminating over-threshold PM10 data produced by natural source from the ones occurred because of anthropogenic causes) in supporting the decisions of the considered end-user (ARPAB) in a pre-operational context.

  8. The species flocks of East African cichlid fishes: recent advances in molecular phylogenetics and population genetics

    NASA Astrophysics Data System (ADS)

    Salzburger, Walter; Meyer, Axel

    With more than 3,000 species, the fish family Cichlidae is one of the most species-rich families of vertebrates. Cichlids occur in southern and central America, Africa, Madagascar, and India. The hotspot of their biodiversity is East Africa, where they form adaptive radiations composed of hundreds of endemic species in several lakes of various sizes and ages. The unparalleled species richness of East African cichlids has been something of a conundrum for evolutionary biologists and ecologists, since it has been in doubt whether these hundreds of species arose by allopatric speciation or whether it is necessary to invoke somewhat less traditional models of speciation, such as micro-allopatric, peripatric, or even sympatric speciation or evolution through sexual selection mediated by female choice. Ernst Mayr's analyses of these evolutionary uniquely diverse species assemblages have contributed to a more direct approach to this problem and have led to a deeper understanding of the patterns and processes that caused the formation of these huge groups of species. We review here recent molecular data on population differentiation and phylogenetics, which have helped to unravel, to some extent, the patterns and processes that led to the formation and ecological maintenance of cichlid species flocks. It is becoming apparent that sexually selected traits do play an important role in speciation in micro-allopatric or even sympatric settings. Species richness seems to be roughly correlated with the surface area, but not the age, of the lakes. We observe that the oldest lineages of a species flock of cichlids are often less species-rich and live in the open water or deepwater habitats. While the species flocks of the Lake Malawai and the Lake Victoria areas were shown to be monophyletic, the cichlid assemblage of Lake Tanganyika seems to consist of several independent species flocks. Cichlids emerge as an evolutionary model system in which many fundamental questions in evolution and ecology can be tested successfully, yet for other fish species flocks the relative importance of alternative mechanisms of speciation is likely to differ from that in cichlid fish.

  9. 670 | VOL.11 NO.6 | JUNE2014 | nAture methods Advances in techniques for recording large-scale brain activity

    E-print Network

    Cai, Long

    Articles 670 | VOL.11 NO.6 | JUNE2014 | nAture methods Advances in techniques for recording large-scale brain activity contribute to both the elucidation of neurophysiological principles and the development of brain-machine interfaces (Bmis). here we describe a neurophysiological paradigm for performing tethered

  10. Advances in fluorescence labeling strategies for dynamic cellular imaging

    PubMed Central

    Dean, Kevin M; Palmer, Amy E

    2014-01-01

    Synergistic advances in optical physics, probe design, molecular biology, labeling techniques and computational analysis have propelled fluorescence imaging into new realms of spatiotemporal resolution and sensitivity. This review aims to discuss advances in fluorescent probes and live-cell labeling strategies, two areas that remain pivotal for future advances in imaging technology. Fluorescent protein– and bio-orthogonal–based methods for protein and RNA imaging are discussed as well as emerging bioengineering techniques that enable their expression at specific genomic loci (for example, CRISPR and TALENs). Important attributes that contribute to the success of each technique are emphasized, providing a guideline for future advances in dynamic live-cell imaging. PMID:24937069

  11. Computer-assisted studies of molecular structure and genotoxic activity by pattern recognition techniques.

    PubMed Central

    Stouch, T R; Jurs, P C

    1985-01-01

    Often a compound's biological activity is determined by complex relationships between its structural components. Such a relationship often can only be adequately described and exploited by multivariate structure-activity relationship (SAR) studies that can deal with many variables simultaneously. Pattern recognition (PR) is a multivariate technique that is well suited for the qualitative, active-inactive, data that is often supplied by biological assays. PR studies of compounds of known activity can yield information that will allow the prediction of the activity of untested compounds. ADAPT is a computerized system that was developed for such PR-SAR studies. A general introduction to this field is presented and the methodology used for such a study is described in the context of an actual study of mutagenic compounds. The data requirements, descriptor generation, and the details of a PR study are discussed. In addition, the example study was chosen to highlight the problems that may occur if a study is not well formulated and carefully executed. Current work and future plans for computerized mutagen screening are discussed. PMID:3905380

  12. Electronic and Molecular Structure Studies of a (Bio)Inorganic Complex A Multi-Technique Approach

    NASA Astrophysics Data System (ADS)

    Bill, Eckhard; Beckmann, Udo; Wieghardt, Karl

    2002-12-01

    The electronic structure of the dimeric iron complex [Fe2(bbpo)Cl4] n- with the tetranionic ligand 1,2-bis(3,5-di-tert-butyl-2-hydroxyphenyl)oxamide was studied in two different oxidation states. Combined Mössbauer and EPR investigations in conjunction with magnetic susceptibility measurements are used to demonstrate the complementarity of the techniques. The dianion [Fe2(bbpo)Cl4]2-(2) is a high-spin iron(III) compound with magnetic properties resulting from competing exchange and zero-field interactions of the iron sites. Unusual integer-spin EPR spectra could be recorded from an excited spin septet, S t=3, of the coupled system. Electrochemical oxidation yields the monoanion [Fe2(bbpoox1)Cl4]- (2 ox ) which also is an iron(III) compound; the ligand is redox non-innocent and forms a ? radical that is bound to one of the iron centers and the total spin S t=1/2 ground states of the molecule originates from exchange coupling of the three paramagnetic centers. A simplified spin coupling scheme assuming infinitively strong radical-iron(III) interaction yields a reasonable and rational interpretation of the magnetic and electronic properties of 2 ox .

  13. Airborne Fungi in Sahara Dust Aerosols Reaching the Eastern Caribbean: II. Species Identification Using Molecular Techniques

    NASA Astrophysics Data System (ADS)

    de La Mota, A.; Betancourt, C.; Detres, Y.; Armstrong, R.

    2003-12-01

    Fungi samples from filters collected in Castle Bruce, Dominica from March through July 2002, were previously purified and identified to genus level using classic macroscopic and microscopic techniques. A total of 105 isolated colonies were cultured in liquid media and the mycelial mats used for DNA extraction. PCR was used to amplify the ITS region of the rDNA using the ITS1 and ITS4 primers. Both strands of the amplified products were sequenced and the final identification to species level was completed by a GenBank search. Fourteen different species and one fungal endophyte were identified from genders Aspergillus,Penicillium, Fusarium, Cladosporium, Curvularia and Phanerochaete. Some of these species such as A. fumigatus, A. japonicus, P. citrinum and C. cladosporoides are known to cause respiratory disorders in humans. A. fumigatus causes an aggressive pulmonary allergic response that might result in allergic bronchopulmonary aspergillosis. Other species such as F. equiseti and C. brachyspora are plant pathogens affecting economically important crops. Sahara dust is an important source of fungal spores of species that are not common in the Caribbean region.

  14. Advances in clinical and molecular understanding of the FMR1 premutation and fragile X-associated tremor/ataxia syndrome

    PubMed Central

    Hagerman, Randi; Hagerman, Paul

    2014-01-01

    Summary Fragile X syndrome, the leading heritable form of cognitive impairment, is caused by epigenetic silencing of the fragile X (FMR1) gene consequent to large expansions (>200 repeats) of a non-coding CGG-repeat element. Smaller, “premutation” expansions (55–200 repeats) can give rise to a family of neurodevelopmental (ADHD, autism spectrum disorder, seizure disorder) and neurodegenerative (FXTAS) clinical phenotypes through an entirely distinct molecular mechanism involving increased FMR1 mRNA production and toxicity. Basic cellular, animal, and human studies have helped to elucidate the underlying RNA toxicity mechanism, while clinical research is providing a more nuanced picture of the spectrum of clinical involvement. Whereas advances on both mechanistic and clinical fronts are driving new approaches to targeted treatment, two important issues/needs are emerging: to define the extent to which the mechanisms contributing to FXTAS also contribute to other neurodegenerative and medical disorders, and to redefine FXTAS in light of its differing presentations and associated features. PMID:23867198

  15. Removal of Lattice Imperfections that Impact the Optical Quality of Ti:Sapphire using Advanced Magnetorheological Finishing Techniques

    SciTech Connect

    Menapace, J A; Schaffers, K I; Bayramian, A J; Davis, P J; Ebbers, C A; Wolfe, J E; Caird, J A; Barty, C J; Joyce, D B; Schmid, K; Schmid, F

    2007-10-09

    Ti:sapphire has become the premier lasing medium material for use in solid-state femtosecond high-peak power laser systems because of its wide wavelength tuning range. With a tuneable range from 680 to 1100 nm, peaking at 800 nm, Ti:sapphire lasing crystals can easily be tuned to the required pump wavelength and provide very high pump brightness due to their good beam quality and high output power of typically several watts. Femtosecond lasers are used for precision cutting and machining of materials ranging from steel to tooth enamel to delicate heart tissue and high explosives. These ultra-short pulses are too brief to transfer heat or shock to the material being cut, which means that cutting, drilling, and machining occur with virtually no damage to surrounding material. Furthermore, these lasers can cut with high precision, making hairline cuts of less than 100 microns in thick materials along a computer-generated path. Extension of laser output to higher energies is limited by the size of the amplification medium. Yields of high quality large diameter crystals have been constrained by lattice distortions that may appear in the boule limiting the usable area from which high quality optics can be harvested. Lattice distortions affect the transmitted wavefront of these optics which ultimately limits the high-end power output and efficiency of the laser system, particularly when operated in multi-pass mode. To make matters even more complicated, Ti:sapphire is extremely hard (Mohs hardness of 9 with diamond being 10) which makes it extremely difficult to accurately polish using conventional methods without subsurface damage or significant wavefront error. In this presentation, we demonstrate for the first time that Magnetorheological finishing (MRF) can be used to compensate for the lattice distortions in Ti:sapphire by perturbing the transmitted wavefront. The advanced MRF techniques developed allow for precise polishing of the optical inverse of lattice distortions with magnitudes of about 70 nm in optical path difference onto one or both of the optical surfaces to produce high quality optics from otherwise unusable Ti:sapphire crystals. The techniques include interferometric, software, and machine modifications to precisely locate and polish sub-millimeter sites onto the optical surfaces that can not be polished into the optics conventionally. This work may allow extension of Ti:sapphire based systems to peak powers well beyond one petawatt.

  16. A FEASIBILITY AND OPTIMIZATION STUDY TO DETERMINE COOLING TIME AND BURNUP OF ADVANCED TEST REACTOR FUELS USING A NONDESTRUCTIVE TECHNIQUE

    SciTech Connect

    Jorge Navarro

    2013-12-01

    The goal of this study presented is to determine the best available non-destructive technique necessary to collect validation data as well as to determine burn-up and cooling time of the fuel elements onsite at the Advanced Test Reactor (ATR) canal. This study makes a recommendation of the viability of implementing a permanent fuel scanning system at the ATR canal and leads3 to the full design of a permanent fuel scan system. The study consisted at first in determining if it was possible and which equipment was necessary to collect useful spectra from ATR fuel elements at the canal adjacent to the reactor. Once it was establish that useful spectra can be obtained at the ATR canal the next step was to determine which detector and which configuration was better suited to predict burnup and cooling time of fuel elements non-destructively. Three different detectors of High Purity Germanium (HPGe), Lanthanum Bromide (LaBr3), and High Pressure Xenon (HPXe) in two system configurations of above and below the water pool were used during the study. The data collected and analyzed was used to create burnup and cooling time calibration prediction curves for ATR fuel. The next stage of the study was to determine which of the three detectors tested was better suited for the permanent system. From spectra taken and the calibration curves obtained, it was determined that although the HPGe detector yielded better results, a detector that could better withstand the harsh environment of the ATR canal was needed. The in-situ nature of the measurements required a rugged fuel scanning system, low in maintenance and easy to control system. Based on the ATR canal feasibility measurements and calibration results it was determined that the LaBr3 detector was the best alternative for canal in-situ measurements; however in order to enhance the quality of the spectra collected using this scintillator a deconvolution method was developed. Following the development of the deconvolution method for ATR applications the technique was tested using one-isotope, multi-isotope and fuel simulated sources. Burnup calibrations were perfomed using convoluted and deconvoluted data. The calibrations results showed burnup prediction by this method improves using deconvolution. The final stage of the deconvolution method development was to perform an irradiation experiment in order to create a surrogate fuel source to test the deconvolution method using experimental data. A conceptual design of the fuel scan system is path forward using the rugged LaBr3 detector in an above the water configuration and deconvolution algorithms.

  17. Using Advanced Remote Sensing Data Fusion Techniques for Studying Earth Surface Processes and Hazards: A Landslide Detection Case Study

    NASA Astrophysics Data System (ADS)

    Hulslander, D.

    2014-12-01

    A major problem in earth surface process and hazards research is we have little to no knowledge of precisely where and when the next significant event may occur. This makes it nearly impossible to set up adequate instrumentation and observation ahead of time. Furthermore, it is not practical to overcome this challenge by instrumenting and observing everywhere all the time. We can't be everywhere and see everything. Remote sensing helps us to fill that gap with missions such as Landsat and WorldView2 offering regular global coverage. However, remote sensing systems for global monitoring have several inherent compromises. Tradeoffs must be made between data storage, processing capacity, spatial resolution, spectral resolution, and temporal resolution. Additionally, instruments and systems must be designed in advance and from a generalized standpoint to serve as many purposes as possible, often at the expense of high performance in specific tasks. Because of these practical constraints, when using remote sensing data to study earth surface processes it is critical to maximize signal content or information obtained from all available data. Several approaches, including multi-temporal data fusion, multi-sensor data fusion, and fusion with derivative products such as band ratios or vegetation indices can help expand how much information can be extracted from remote sensing acquisitions. Fused dataset results contain more coherent information than the sum of their individual constituents. Examples using Landsat and WorldView2 data in this study show this added information makes it possible to map earth surface processes and events, such as the 2011 Cinque Terre landslides, in a more automated and repeatable fashion over larger areas than is possible with manual imagery analysis techniques and with greater chance of successful detection.

  18. Environmental Forensics: Molecular Insight into Oil Spill Weathering Helps Advance High Magnetic Field FT-ICR Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    McKenna, Amy

    2013-03-01

    The depletion of terrestrial global oil reserves has shifted oil exploration into offshore and ultra-deep water (> 5000 ft) oil reserves to meet global energy demands. Deep water reservoirs are currently in production in many parts of the world, including the Gulf of Mexico, but production is complicated by the water depth and thick salt caps that challenge reservoir characterization / production. The explosion aboard the Deepwater Horizon in April 2010 resulted in an estimated total release of ~5 million barrels (BP claims that they collected ~1M barrels, for a net release of 4 M) of light, sweet crude oil into the Gulf of Mexico and shifted attention toward the environmental risks associated with offshore oil production. The growing emphasis on deep water and ultra-deep water oil production poses a significant environmental threat, and increased regulations require that oil companies minimize environmental impact to prevent oil spills, and mitigate environmental damage when spills occur. Every oil spill is unique. The molecular transformations that occur to petroleum after contact with seawater depend on the physical and chemical properties of the spilled oil, environmental conditions, and deposition environment. Molecular-level knowledge of the composition, distribution, and total mass of released hydrocarbons is essential to disentangle photo- and bio-degradation, source identification, and long-term environmental impact of hydrocarbons released into the environment. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) is unsurpassed in its ability to characterize complex mixtures at the level of elemental composition assignment. Only FT-ICR mass spectrometry can routinely achieve the required minimum resolving power necessary to elucidate molecular-level characterization of crude oil. Conversely, the spectral complexity of petroleum facilitates identification of systematic errors in the accumulation, transfer, excitation, and detection events in the FT-ICR experiment. For example, the high density of peaks at each nominal mass unit provides unprecedented insight into how excitation conditions affect ion motion during detection. Aggregated oil (i.e., tar balls, tar mats) that reached the surface exhibits a more than two-fold increase in the total number of detected species, with an increased number of oxygenated species. Principal component analysis (PCA) applied to two possible source oils (contained within the same ship) and weathered samples provide the first application of FT-ICR MS for source identification. Molecular formulae from parent and weathered oil indicate that the lightest petroleum fractions (saturated hydrocarbons) are the most readily oxidized components, and can serve as a template to determine chemical transformations that occur throughout the water column. The ability to differentiate and catalogue compositional changes that occur to oil after its release into the environment relies heavily on gains achieved in nearly all steps in the FT-ICR mass spectral experiment required to accommodate larger ion populations inherent to heavily weathered crude oil. Here, we present the requirement for FT-ICR MS for comprehensive oil spill characterization, and highlight advances made to FT-ICR MS experimental conditions developed from petroleum characterization. Work supported by DMR-06-54118, NSF CHE-10-49753 (RAPID), BP/The Gulf of Mexico Research Initiative, and the State of Florida

  19. Molecular Epidemiology of EGFR Mutations in Asian Patients with Advanced Non-Small-Cell Lung Cancer of Adenocarcinoma Histology – Mainland China Subset Analysis of the PIONEER study

    PubMed Central

    Shi, Yuankai; Li, Junling; Zhang, Shucai; Wang, Mengzhao; Yang, Shujun; Li, Ning; Wu, Gang; Liu, Wei; Liao, Guoqing; Cai, Kaican; Chen, Liang’an; Zheng, Meizhen; Yu, Ping; Wang, Xiuwen; Liu, Yunpeng; Guo, Qisen; Nie, Ligong; Liu, Jiwei; Han, Xiaohong

    2015-01-01

    Epidermal growth factor receptor (EGFR) mutations are the strongest response predictors to EGFR tyrosine kinase inhibitors (TKI) therapy, but knowledge of the EGFR mutation frequency on lung adenocarcinoma is still limited to retrospective studies. The PIONEER study (NCT01185314) is a prospective molecular epidemiology study in Asian patients with newly diagnosed advanced lung adenocarcinoma, aiming to prospectively analyze EGFR mutation status in IIIB/IV treatment-naïve lung adenocarcinomas in Asia. We report the mainland China subset results. Eligible patients (?20 yrs old, IIIB/IV adenocarcinoma and treatment-naïve) were registered in 17 hospitals in mainland China. EGFR was tested for mutations by amplification refractory mutation system using biopsy samples. Demographic and clinical characteristics were collected for subgroup analyses. A total of 747 patients were registered. Successful EGFR mutation analysis was performed in 741, with an overall mutation rate of 50.2%. The EGFR active mutation rate is 48.0% (with 1.3% of combined active and resistance mutations). Tobacco use (>30 pack-year vs. 0–10 pack-year, OR 0.27, 95%CI: 0.17–0.42) and regional lymph nodes involvement (N3 vs. N0, OR 0.47, 95%CI: 0.29–0.76) were independent predictors of EGFR mutation in multivariate analysis. However, even in regular smokers, the EGFR mutation frequency was 35.3%. The EGFR mutation frequency was similar between diverse biopsy sites and techniques. The overall EGFR mutation frequency of the mainland China subset was 50.2%, independently associated with the intensity of tobacco use and regional lymph nodes involvement. The relatively high frequency of EGFR mutations in the mainland China subset suggest that any effort to obtain tissue sample for EGFR mutation testing should be encouraged. PMID:26599344

  20. The usefulness of molecular techniques to assess the presence of Aeromonas spp. harboring virulence markers in foods.

    PubMed

    Bin Kingombe, César I; Huys, Geert; Howald, Denise; Luthi, Elisabeth; Swings, Jean; Jemmi, Thomas

    2004-07-15

    A total of 78 raw and 123 processed and ready-to-eat retail food samples were used to assess the presence of motile Aeromonas spp. harboring virulence genes (cytotoxic enterotoxin and hemolysin genes) using a recently described PCR method in comparison with the conventional cultivation method based on the use of Ampicillin-Dextrin Agar (ADA) medium. With the ADA-based method, 65/201 (32.3%) samples showed presumptive Aeromonas spp. colonies whereas the PCR method revealed the presence of Aeromonas spp. harboring the targeted virulence genes in 51/201 (25.4%) of the tested samples. The rate of contaminated samples and the presence of pathogenic Aeromonas were significantly lower with both methods for processed than in case of raw samples. A polyphasic identification approach including biochemical and molecular techniques was applied to a selection of 34 PCR-positive presumptive Aeromonas isolates. Following fatty acid methyl ester (FAME) analysis and amplified fragment length polymorphism (AFLP) fingerprinting, a total of 33 isolates (97%) could be identified to the DNA hybridization group (HG) level. The majority of these isolates belonged to the species Aeromonas hydrophila HG3 (50%) and Aeromonas veronii biovar sobria (HG8/10) (38%). Molecular characterization of PCR amplicons obtained from these strains by PCR-Restriction Fragment Length Polymorphism (PCR-RFLP) fingerprinting and PCR-Amplicon Sequence Analysis (PCR-ASA) allowed classification of all strains in a known PCR-RFLP and PCR-ASA type. In conclusion, the current findings demonstrate that the combined use of PCR-based virulence marker detection, PCR-RFLP and PCR-ASA offers a rapid, sensitive, and specific system to assess the presence and prevalence of Aeromonas spp. harboring virulence markers in food samples. PMID:15193799