Sample records for advanced molecular techniques

  1. Advanced molecular biologic techniques in toxicologic disease.

    PubMed

    Ward, Jeanine; Szabo, Gyongyi; McManus, David; Boyer, Edward

    2011-12-01

    The advancement of molecular biologic techniques and their capabilities to answer questions pertaining to mechanisms of pathophysiologic events have greatly expanded over the past few years. In particular, these opportunities have provided researchers and clinicians alike the framework from with which to answer clinical questions not amenable for elucidation using previous, more antiquated methods. Utilizing extremely small molecules, namely microRNA, DNA, protein, and nanoparticles, we discuss the background and utility of these approaches to the progressive, practicing physician. Finally, we consider the application of these tools employed as future bedside point of care tests, aiding in the ultimate goal of unsurpassed patient care. PMID:22072091

  2. Recent advances and techniques in synchrotron radiation based molecular physics

    Microsoft Academic Search

    P. A Hatherly; B. O Fisher; D. J Collins; M Stankiewicz; M. D Roper

    2001-01-01

    The application of synchrotron radiation to problems in molecular physics has proved highly successful, producing wide-ranging scientific data and spawning developments in experimental techniques and apparatus. As a particular example, studies of soft X-ray (0.1–1 keV) interaction with molecules are essentially not possible without access to synchrotron radiation. In this paper, we present experimental details and recent results of work

  3. Advanced Techniques for Constrained Internal Coordinate Molecular Dynamics

    PubMed Central

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

    2013-01-01

    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 in order to make the CICMD method robust and widely usable. In this paper we have designed a new framework for 1) initializing velocities for non-independent 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 paper, 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 MD 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

  4. Exploration of advanced characterization techniques for molecular composites. Final report, February 1984-January 1985

    SciTech Connect

    VanderHart, D.L.; Wang, F.W.; Eby, R.K.; Fanconi, B.M.; DeVries, K.L.

    1986-02-01

    The techniques of solid-state nuclear magnetic resonance, fluorescence spectroscopy, electron-spin resonance, and x-ray diffraction were applied to characterize aspects of the solid-state structures of rigid-rod polymers and their blends with flexible polymers. NMR and fluorescence spectroscopies were used to investigate the degree to which the rigid rod - flexible polymers blends exist as phase-separated systems. It was found that these materials form primarily phase-segregated structures, a condition that limits the reinforcing potential of rigid rod polymers in molecular composites. Most specimens also reinforcing potential of rigid-rod polymers in molecular composites. Most specimens also exhibited NMR signals indicative of mobile, and presumably lower-molecular-weight, species. It is postulated that these mobile species are either water or residual acid from which the materials are processed. Information regarding the location of the mobile species in the structures exhibited by rigid-rod polymers and their blends with flexible polymers is deduced from NMR. Electron-spin resonance measurements confirmed that free radicals are generated during mechanically stressing rigid-rod polymer fibers. The as-processed fibers contained appreciable levels of free radicals, and annealing at elevated temperatures caused a decrease in the free-radical concentration by a factor of three. X-ray-diffraction experiments were conducted at elevated pressure in a diamond anvil cell. The observed diffraction pattern is suggestive of the formation of a more ordered structure at elevated pressures.

  5. Recent Advances in Nanobiotechnology and High-Throughput Molecular Techniques for Systems Biomedicine

    PubMed Central

    Kim, Eung-Sam; Ahn, Eun Hyun; Chung, Euiheon; Kim, Deok-Ho

    2013-01-01

    Nanotechnology-based tools are beginning to emerge as promising platforms for quantitative high-throughput analysis of live cells and tissues. Despite unprecedented progress made over the last decade, a challenge still lies in integrating emerging nanotechnology-based tools into macroscopic biomedical apparatuses for practical purposes in biomedical sciences. In this review, we discuss the recent advances and limitations in the analysis and control of mechanical, biochemical, fluidic, and optical interactions in the interface areas of nanotechnology-based materials and living cells in both in vitro and in vivo settings. PMID:24258011

  6. Molecular Techniques in Hematopathology

    Microsoft Academic Search

    Bobby L. Boyanton Jr; Jennifer R. Rushton

    \\u000a The discipline of hematopathology traditionally relies upon morphologic evaluation, cytochemical stains, immunohistochemistry,\\u000a flow cytometry, and karyotypic analysis to classify hematolymphoid neoplasms. Although these time-honored methods still comprise\\u000a the primary diagnostic arsenal of the pathologist, the last few decades have borne witness to the widespread acceptance of\\u000a molecular techniques to classify these neoplasms. No longer considered ancillary, molecular analyses have led

  7. Techniques for Molecular Imaging Probe Design

    PubMed Central

    Reynolds, Fred; Kelly, Kimberly A.

    2011-01-01

    Molecular imaging allows clinicians to visualize disease specific molecules, thereby providing relevant information in the diagnosis and treatment of patients. With advances in genomics and proteomics and underlying mechanisms of disease pathology, the number of targets identified has significantly outpaced the number of developed molecular imaging probes. There has been a concerted effort to bridge this gap with multidisciplinary efforts in chemistry, proteomics, physics, material science, and biology; all essential to progress in molecular imaging probe development. In this review, we will discuss target selection, screening techniques and probe optimization with the aim of developing clinically relevant molecularly targeted imaging agents. PMID:22201532

  8. Advanced Coating Removal Techniques

    NASA Technical Reports Server (NTRS)

    Seibert, Jon

    2006-01-01

    An important step in the repair and protection against corrosion damage is the safe removal of the oxidation and protective coatings without further damaging the integrity of the substrate. Two such methods that are proving to be safe and effective in this task are liquid nitrogen and laser removal operations. Laser technology used for the removal of protective coatings is currently being researched and implemented in various areas of the aerospace industry. Delivering thousands of focused energy pulses, the laser ablates the coating surface by heating and dissolving the material applied to the substrate. The metal substrate will reflect the laser and redirect the energy to any remaining protective coating, thus preventing any collateral damage the substrate may suffer throughout the process. Liquid nitrogen jets are comparable to blasting with an ultra high-pressure water jet but without the residual liquid that requires collection and removal .As the liquid nitrogen reaches the surface it is transformed into gaseous nitrogen and reenters the atmosphere without any contamination to surrounding hardware. These innovative technologies simplify corrosion repair by eliminating hazardous chemicals and repetitive manual labor from the coating removal process. One very significant advantage is the reduction of particulate contamination exposure to personnel. With the removal of coatings adjacent to sensitive flight hardware, a benefit of each technique for the space program is that no contamination such as beads, water, or sanding residue is left behind when the job is finished. One primary concern is the safe removal of coatings from thin aluminum honeycomb face sheet. NASA recently conducted thermal testing on liquid nitrogen systems and found that no damage occurred on 1/6", aluminum substrates. Wright Patterson Air Force Base in conjunction with Boeing and NASA is currently testing the laser remOval technique for process qualification. Other applications of liquid nitrogen operations include cutting of both soft and hard materials. While the laser will not cut materials, it can be used to roughen surfaces and to remove other materials from the substrate including oil, grease, and mold. The space program can benefit from several of these applications with the need for precise removal of coatings and other organic compounds in areas adjacent to sensitive space flight hardware. Significant advantages are evident when comparing liquid nitrogen and laser removal operations over current techniques of media blasting and sanding.

  9. Advanced qualification techniques

    SciTech Connect

    Winokur, P.S; Shaneyfelt, M.R.; Meisenheimer, T.L.; Fleetwood, D.M.

    1993-12-01

    This paper demonstrates use of the Qualified Manufacturers List (QML) methodology to qualify commercial and military microelectronics for use in space applications. QML ``builds in`` the hardness of product through statistical process control (SPC) of technology parameters relevant to the radiation response, test structure to integrated circuit (IC) correlations, and techniques for extrapolating laboratory test results to low-dose-rate space scenarios. Each of these elements is demonstrated and shown to be a cost-effective alternative to expensive end-of-line IC testing. Several examples of test structured-IC correlations are provided and recent work on complications arising from transistor scaling and geometry is discussed. The use of a 10-keV x-ray wafer-level test system to support SPC and establish ``process capability`` is illustrated and a comparison of 10-keV x-ray and Co{sup 60} gamma irradiations is provided for a wide range of CMOS technologies. The x-ray tester is shown to be cost-effective and its use in lot acceptance/qualification is recommended. Finally, a comparison is provided between MIL-STD-883D, Test Method 1019.4, which governs the testing of packaged semiconductor microcircuits in the DoD, and ESA/SSC Basic Specification No. 22900, Europe`s Total Dose Steady-State Irradiation Test Method. Test Method 1019.4 focuses on conservative estimates of MOS hardness for space and tactical applications, while Basic Specification 22900 focuses on improved simulation of low-dose-rate space environments.

  10. Review of advanced imaging techniques

    PubMed Central

    Chen, Yu; Liang, Chia-Pin; Liu, Yang; Fischer, Andrew H.; Parwani, Anil V.; Pantanowitz, Liron

    2012-01-01

    Pathology informatics encompasses digital imaging and related applications. Several specialized microscopy techniques have emerged which permit the acquisition of digital images (“optical biopsies”) at high resolution. Coupled with fiber-optic and micro-optic components, some of these imaging techniques (e.g., optical coherence tomography) are now integrated with a wide range of imaging devices such as endoscopes, laparoscopes, catheters, and needles that enable imaging inside the body. These advanced imaging modalities have exciting diagnostic potential and introduce new opportunities in pathology. Therefore, it is important that pathology informaticists understand these advanced imaging techniques and the impact they have on pathology. This paper reviews several recently developed microscopic techniques, including diffraction-limited methods (e.g., confocal microscopy, 2-photon microscopy, 4Pi microscopy, and spatially modulated illumination microscopy) and subdiffraction techniques (e.g., photoactivated localization microscopy, stochastic optical reconstruction microscopy, and stimulated emission depletion microscopy). This article serves as a primer for pathology informaticists, highlighting the fundamentals and applications of advanced optical imaging techniques. PMID:22754737

  11. Advanced techniques for microwave reflectometry

    SciTech Connect

    Sanchez, J.; Branas, B.; Luna, E. de la; Estrada, T. [Asociacion Euratom-CIEMAT, Madrid (Spain); Zhuravlev, V. [Asociacion Euratom-CIEMAT, Madrid (Spain)]|[Kurchatov Institute, Moscow (Russian Federation); Hartfuss, H.J.; Hirsch, M.; Geist, T. [Max-Planck Institut fuer Plasmaphysik, Garching (Germany); Segovia, J.; Oramas, J.L. [Univ. Politecnica, Madrid (Spain)

    1994-12-31

    Microwave reflectometry has been applied during the last years as a plasma diagnostic of increasing interest, mainly due to its simplicity, no need for large access ports and low radiation damage of exposed components. Those characteristics make reflectometry an attractive diagnostic for the next generation devices. Systems used either for density profile or density fluctuations have also shown great development, from the original single channel heterodyne to the multichannel homodyne receivers. In the present work we discuss three different advanced reflectometer systems developed by CIEMAT members in collaboration with different institutions. The first one is the broadband heterodyne reflectometer installed on W7AS for density fluctuations measurements. The decoupling of the phase and amplitude of the reflected beam allows for quantitative analysis of the fluctuations. Recent results showing the behavior of the density turbulence during the L-H transition on W7AS are shown. The second system shows how the effect of the turbulence can be used for density profile measurements by reflectometry in situations where the complicated geometry of the waveguides cannot avoid many parasitic reflections. Experiments from the TJ-I tokamak will be shown. Finally, a reflectometer system based on the Amplitude Modulation (AM) technique for density profile measurements is discussed and experimental results from the TJ-I tokamak are shown. The AM system offers the advantage of being almost insensitive to the effect of fluctuations. It is able to take a direct measurement of the time delay of the microwave pulse which propagates to the reflecting layer and is reflected back. In order to achieve fast reconstruction for real time monitoring of the density profile application of Neural Networks algorithms will be presented the method can reduce the computing times by about three orders of magnitude. 10 refs., 10 figs.

  12. Advanced spacecraft thermal control techniques

    Microsoft Academic Search

    C. H. Fritz

    1977-01-01

    The problems of rejecting large amounts of heat from spacecraft were studied. Shuttle Space Laboratory heat rejection uses 1 kW for pumps and fans for every 5 kW (thermal) heat rejection. This is rather inefficient, and for future programs more efficient methods were examined. Two advanced systems were studied and compared to the present pumped-loop system. The advanced concepts are

  13. The application of advanced analytical techniques to direct coal liquefaction

    SciTech Connect

    Brandes, S.D.; Winschel, R.A.; Burke, F.P.; Robbins, G.A.

    1991-12-31

    Consol is coordinating a program designed to bridge the gap between the advanced, modern techniques of the analytical chemist and the application of those techniques by the direct coal liquefaction process developer, and to advance our knowledge of the process chemistry of direct coal liquefaction. The program is designed to provide well-documented samples to researchers who are utilizing techniques potentially useful for the analysis of coal derived samples. The choice of samples and techniques was based on an extensive survey made by Consol of the present status of analytical methodology associated with direct coal liquefaction technology. Sources of information included process developers and analytical chemists. Identified in the survey are a number of broadly characterizable needs. These categories include a need for: A better understanding of the nature of the high molecular weight, non-distillable residual materials (both soluble and insoluble) in the process streams; improved techniques for molecular characterization, heteroatom and hydrogen speciation and a knowledge of the hydrocarbon structural changes across coal liquefaction systems; better methods for sample separation; application of advanced data analysis methods; the use of more advanced predictive models; on-line analytical techniques; and better methods for catalyst monitoring.

  14. The application of advanced analytical techniques to direct coal liquefaction

    SciTech Connect

    Brandes, S.D.; Winschel, R.A.; Burke, F.P.; Robbins, G.A.

    1991-01-01

    Consol is coordinating a program designed to bridge the gap between the advanced, modern techniques of the analytical chemist and the application of those techniques by the direct coal liquefaction process developer, and to advance our knowledge of the process chemistry of direct coal liquefaction. The program is designed to provide well-documented samples to researchers who are utilizing techniques potentially useful for the analysis of coal derived samples. The choice of samples and techniques was based on an extensive survey made by Consol of the present status of analytical methodology associated with direct coal liquefaction technology. Sources of information included process developers and analytical chemists. Identified in the survey are a number of broadly characterizable needs. These categories include a need for: A better understanding of the nature of the high molecular weight, non-distillable residual materials (both soluble and insoluble) in the process streams; improved techniques for molecular characterization, heteroatom and hydrogen speciation and a knowledge of the hydrocarbon structural changes across coal liquefaction systems; better methods for sample separation; application of advanced data analysis methods; the use of more advanced predictive models; on-line analytical techniques; and better methods for catalyst monitoring.

  15. 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."

  16. Advances in Molecular Imaging with Ultrasound

    PubMed Central

    Gessner, Ryan; Dayton, Paul A.

    2010-01-01

    Ultrasound imaging has long demonstrated utility in the study and measurement of anatomic features and noninvasive observation of blood flow. Within the last decade, advances in molecular biology and contrast agents have allowed researchers to use ultrasound to detect changes in the expression of molecular markers on the vascular endothelium and other intravascular targets. This new technology, referred to as ultrasonic molecular imaging, is still in its infancy. However, in preclinical studies, ultrasonic molecular imaging has shown promise in assessing angiogenesis, inflammation, and thrombus. In this review, we discuss recent advances in microbubble-type contrast agent development, ultrasound technology, and signal processing strategies that have the potential to substantially improve the capabilities and utility of ultrasonic molecular imaging. PMID:20487678

  17. Advances in multimodality molecular imaging

    Microsoft Academic Search

    Habib Zaidi; Rameshwar Prasad

    2009-01-01

    Multimodality molecular imaging using high resolution positron emission tomography (PET) combined with other modalities is now playing a pivotal role in basic and clinical research. The introduction of combined PET\\/CT systems in clinical setting has revolutionized the practice of diagnostic imaging. The complementarity between the intrinsically aligned anatomic (CT) and functional or metabolic (PET) information provided in a \\

  18. Advanced Techniques Using Contrast Media in Neuroimaging

    PubMed Central

    Ferré, Jean-Christophe; Shiroishi, Mark S.; Law, Meng

    2012-01-01

    This article presents an overview of advanced MRI techniques using contrast media in neuroimaging, focusing on T2*-weighted dynamic susceptibility contrast MR imaging (DSC-MRI) and T1-weighted dynamic contrast-enhanced MR imaging (DCE-MRI). Image acquisition and data processing methods as well as their clinical application in brain tumors, stroke, dementia and multiple sclerosis are discussed. PMID:23088946

  19. Advanced Metamorphic Techniques in Computer Philippe Beaucamps

    E-print Network

    Paris-Sud XI, Université de

    of virus protection techniques against detection and then study the METAPHOR virus, today's most advanced mutate its binary form on each replication: as early as in 1988 a first virus protected itself using "popularity". Nevertheless antiviruses quickly adapted to this protection by letting viruses decrypt

  20. Advances in alternative DNA delivery techniques

    Microsoft Academic Search

    D. D. Songstad; D. A. Somers; R. J. Griesbach

    1995-01-01

    This review describes recent advances in alternative DNA-delivery techniques with particular emphasis on silicon carbide fibers, intact tissue electroporation, electrophoresis and microinjection. The advantages\\/disadvantages of each method along with a historical overview and theory of practice are discussed.

  1. Advances in techniques for diagnosing fusion plasmas

    Microsoft Academic Search

    Peter E Stott

    1997-01-01

    Fusion research relies heavily on plasma diagnostics in order to operate safely, to explore and optimise the performance of a fusion experiment and to study in detail the plasma physics. In recent years, there have been many advances in plasma diagnostics, not only as a result of the development of new and innovative techniques, but also by the improvement and

  2. Advances in plant molecular farming.

    PubMed

    Obembe, Olawole O; Popoola, Jacob O; Leelavathi, Sadhu; Reddy, Siva V

    2011-01-01

    Plant molecular farming (PMF) is a new branch of plant biotechnology, where plants are engineered to produce recombinant pharmaceutical and industrial proteins in large quantities. As an emerging subdivision of the biopharmaceutical industry, PMF is still trying to gain comparable social acceptance as the already established production systems that produce these high valued proteins in microbial, yeast, or mammalian expression systems. This article reviews the various cost-effective technologies and strategies, which are being developed to improve yield and quality of the plant-derived pharmaceuticals, thereby making plant-based production system suitable alternatives to the existing systems. It also attempts to overview the different novel plant-derived pharmaceuticals and non-pharmaceutical protein products that are at various stages of clinical development or commercialization. It then discusses the biosafety and regulatory issues, which are crucial (if strictly adhered to) to eliminating potential health and environmental risks, which in turn is necessary to earning favorable public perception, thus ensuring the success of the industry. PMID:21115109

  3. 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

  4. Emerging techniques and molecular imaging in breast cancer.

    PubMed

    Yang, Wei Tse

    2011-08-01

    The sensitivity of screening mammography is limited in the evaluation of dense breasts, with as few as 45% of cancers visible in extremely dense breasts. Supplementary imaging for improved sensitivity in women with dense breasts is necessary to overcome this limitation. Emerging technologies that advance the applications of digital mammography include digital breast tomosynthesis and dedicated breast cone-beam computed tomography. Molecular imaging goes beyond structural imaging. A functional imaging technique that provides information on the biology, physiology, and metabolic pathways of cancer might help to improve the sensitivity and specificity of breast cancer diagnosis, facilitate early assessment of treatment response, and help individualize therapy options for patients. Advanced magnetic resonance, nuclear medicine, and optical imaging techniques in the realm of molecular imaging will be explored in this article. PMID:21782119

  5. Advanced Techniques for MRI of Atherosclerotic Plaque

    PubMed Central

    Kerwin, William S.; Canton, Gador

    2011-01-01

    This review examines the state of the art in vessel wall imaging by 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 in regards to how they facilitate accurate determination of plaque constituents underlying biomechanics. Second, imaging technologies, including hardware and sequences, are reviewed in regards to how they provide the resolution and SNR 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

  6. 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.

  7. Advanced decision aiding techniques applicable to space

    NASA Technical Reports Server (NTRS)

    Kruchten, Robert J.

    1987-01-01

    RADC has had an intensive program to show the feasibility of applying advanced technology to Air Force decision aiding situations. Some aspects of the program, such as Satellite Autonomy, are directly applicable to space systems. For example, RADC has shown the feasibility of decision aids that combine the advantages of laser disks and computer generated graphics; decision aids that interface object-oriented programs with expert systems; decision aids that solve path optimization problems; etc. Some of the key techniques that could be used in space applications are reviewed. Current applications are reviewed along with their advantages and disadvantages, and examples are given of possible space applications. The emphasis is to share RADC experience in decision aiding techniques.

  8. Advanced AE Techniques in Composite Materials Research

    NASA Technical Reports Server (NTRS)

    Prosser, William H.

    1996-01-01

    Advanced, waveform based acoustic emission (AE) techniques have been successfully used to evaluate damage mechanisms in laboratory testing of composite coupons. An example is presented in which the initiation of transverse matrix cracking was monitored. 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 specimens or structures, the effects of modal wave propagation over larger distances and through structural complexities must be well characterized and understood. To demonstrate these effects, measurements of the far field, peak amplitude attenuation of the extensional and flexural plate mode components of broad band simulated AE signals in large composite panels are discussed. These measurements demonstrated that the flexural mode attenuation is dominated by dispersion effects. Thus, it is significantly affected by the thickness of the composite plate. Furthermore, the flexural mode attenuation can be significantly larger than that of the extensional mode even though its peak amplitude consists of much lower frequency components.

  9. Advanced techniques in current signature analysis

    SciTech Connect

    Smith, S.F.; Castleberry, K.N.

    1992-03-01

    In general, both ac and dc motors can be characterized as weakly nonlinear systems, in which both linear and nonlinear effects occur simultaneously. Fortunately, the nonlinearities are generally well behaved and understood and an be handled via several standard mathematical techniques already well developed in the systems modeling area; examples are piecewise linear approximations and Volterra series representations. Field measurements of numerous motors and motor-driven systems confirm the rather complex nature of motor current spectra and illustrate both linear and nonlinear effects (including line harmonics and modulation components). Although previous current signature analysis (CSA) work at Oak Ridge and other sites has principally focused on the modulation mechanisms and detection methods (AM, PM, and FM), more recent studies have been conducted on linear spectral components (those appearing in the electric current at their actual frequencies and not as modulation sidebands). For example, large axial-flow compressors ({approximately}3300 hp) in the US gaseous diffusion uranium enrichment plants exhibit running-speed ({approximately}20 Hz) and high-frequency vibrational information (>1 kHz) in their motor current spectra. Several signal-processing techniques developed to facilitate analysis of these components, including specialized filtering schemes, are presented. Finally, concepts for the designs of advanced digitally based CSA units are offered, which should serve to foster the development of much more computationally capable ``smart`` CSA instrumentation in the next several years. 3 refs.

  10. 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

  11. Molecular targeted therapy for advanced gastric cancer

    PubMed Central

    2013-01-01

    Although medical treatment has been shown to improve quality of life and prolong survival, no significant progress has been made in the treatment of advanced gastric cancer (AGC) within the last two decades. Thus, the optimum standard first-line chemotherapy regimen for AGC remains debatable, and most responses to chemotherapy are partial and of short duration; the median survival is approximately 7 to 11 months, and survival at 2 years is exceptionally > 10%. Recently, remarkable progress in tumor biology has led to the development of new agents that target critical aspects of oncogenic pathways. For AGC, many molecular targeting agents have been evaluated in international randomized studies, and trastuzumab, an anti-HER-2 monoclonal antibody, has shown antitumor activity against HER-2-positive AGC. However, this benefit is limited to only ~20% of patients with AGC (patients with HER-2-positive AGC). Therefore, there remains a critical need for both the development of more effective agents and the identification of molecular predictive and prognostic markers to select those patients who will benefit most from specific chemotherapeutic regimens and targeted therapies. PMID:23525404

  12. Molecular biomarkers in advanced renal cell carcinoma.

    PubMed

    Maroto, Pablo; Rini, Brian

    2014-04-15

    The availability of agents directly targeting tumorigenic and angiogenic pathways has significantly improved the outcomes of patients with advanced renal cell carcinoma (RCC) in recent years. However, all patients eventually become resistant and a substantial percentage experience immediate disease progression with first-line targeted therapy. In addition, patients have variable clinical benefit and/or tolerance to different agents, including drugs within the same class. Thus, the choice of therapy for an individual patient remains empiric at present. Upon this landscape, several molecular biomarkers have been investigated with the purpose of guiding therapy. This review discusses prognostic biomarkers correlating with the outcome of patients independent of therapy, and predictive biomarkers of treatment response, including circulating biomarkers (such as VEGF and VEGF-related proteins, cytokine and angiogenic factors, and lactate dehydrogenase), and tissue-based biomarkers (such as single-nucleotide polymorphisms). Many potential prognostic and predictive molecular biomarkers have now been identified in RCC, although none has yet entered into clinical practice, and all require prospective validation in appropriately designed randomized studies. In the near future, however, validated biomarkers may become integral to management strategies in RCC, enabling tailored treatment for individual patients to improve clinical outcomes. PMID:24526734

  13. Microcomposition of Human Urinary Calculi Using Advanced Imaging Techniques

    PubMed Central

    Blaschko, Sarah D.; Miller, Joe; Chi, Thomas; Flechner, Lawrence; Fakra, Sirine; Kahn, Arnold; Kapahi, Pankaj; Stoller, Marshall L.

    2013-01-01

    Purpose Common methods of commercial urolithiasis analysis, such as light microscopy and Fourier transform infrared spectroscopy, provide limited or no information on the molecular composition of stones, which is vital when studying early stone pathogenesis. We used synchrotron radiation based microfocused x-ray fluorescence, x-ray absorption and x-ray diffraction advanced imaging techniques to identify and map the elemental composition, including trace elements, of urinary calculi on a ?m (0.0001 cm) scale. Materials and Methods Human stone samples were obtained during serial percutaneous nephrolithotomy and ureteroscopy procedures. A portion of each sample was sent for commercial stone analysis and a portion was retained for synchrotron radiation based advanced imaging analysis. Results Synchrotron radiation based methods of stone analysis correctly identified stone composition and provided additional molecular detail on elemental components and spatial distribution in uroliths. Resolution was on the order of a few ?m. Conclusions Knowledge of all elements present in lithogenesis at this detail allows for better understanding of early stone formation events, which may provide additional insight to prevent and treat stone formation. PMID:23021997

  14. 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

  15. Below-the-knee revascularization. Advanced techniques.

    PubMed

    SCHWARZWALDER, U; ZELLER, T

    2009-10-01

    This review summarizes new developments in revascularization and advanced techniques to treat lesions below the knee (BTK). The primary goal of endovascular therapy is the re-establishment of pulsatile, straight-line flow to the foot. This treatment results in relieving ischemic pain, healing of (neuro)ischemic ulcers, preventing limb loss, improving quality of life and potentially prolong survival. Balloon angioplasty is the currently established therapy, bare-metal stents are reserved for failed percutaneous transluminal angioplasty (PTA). Novel devices such as laser, excisional and rotational atherectomy systems, drug eluting stents or drug coated balloons still lack data demonstrating improved efficacy compared to conventional balloon angioplasty. The typical patient group of complex below-the-knee lesions represents an increasing population due to the increasing prevalence of diabetes and end-stage renal failure. Excellent acute technical success rates above 90%, a low frequency of complications, and high limb salvage rate of about 95% even in patients with long segment and diffuse disease seem to justify a more widespread use of endovascular therapy in tibial arteries. However, the current results of balloon angioplasty studies show a 1-year restenosis rate between 30% for short stenoses treatment and up to 80% following recanalization of an occlusion. PMID:19741578

  16. 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.

  17. The impact of advanced diagnostic techniques on electrothermal thruster design

    NASA Astrophysics Data System (ADS)

    Janson, S. W.

    1992-07-01

    Diagnostic techniques are described that can be used to measure efficiency loss mechanisms that hinder electrothermal thruster performance. The requirements of electric thrusters are discussed for a range of applications, and ideal electrothermal thruster performance is explained analytically. Advanced diagnostics are described that probe plume flow at the molecular level to derive species- and state-specific information that can verify the models of thruster operation. Measurements are reported of thermal radiation losses, dissociation, rotational and vibrational state distributions, and mass-selected plume velocity. Vibrational, rotational, and translational temperatures of 930-2100 K are found for the plume of a low-power hydrogen arcjet operating with an Isp of about 850 s. Satisfactory performance gains for electrothermal thrusters can be achieved by redesigning constrictor/nozzle geometries to minimze supersonic heating.

  18. Stochastic molecular dynamics: A combined Monte Carlo and molecular dynamics technique for isothermal simulations

    E-print Network

    Attard, Phil

    Stochastic molecular dynamics: A combined Monte Carlo and molecular dynamics technique techniques--Monte Carlo and molecular dynamics--has their own advantage. The molecular dynamics method can to cover the important states of the system in an efficient manner. In recent years the molecular dynamics

  19. 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.

  20. EDITORIAL: Advanced Measurement Techniques in Aerodynamics Advanced Measurement Techniques in Aerodynamics

    NASA Astrophysics Data System (ADS)

    van Oudheusden, B. W.; Scarano, F.

    2009-07-01

    This issue of Measurement Science and Technology contains a special feature section with selected papers from the EWA International workshop on Advanced Measurement Techniques in Aerodynamics, which was held at the Delft University of Technology, Delft, The Netherlands, 31 March-1 April 2008. The workshop was funded by the European Windtunnel Association (EWA, www.eu-ewa.aero), which is an EU-funded network established in 2004 under the European Sixth Framework Programme with the goal of integrating and standardizing the different capabilities of European wind tunnels and related flow measurement techniques. The workshop was organized with the objective of stimulating discussion among leading European universities, research institutes and industry in the field of advanced aerodynamics measurement techniques, in order to provide a transfer of new ideas from upstream research centres to wind tunnel operators and industrial users. Non-intrusive flow diagnostic techniques nowadays offer renewed capabilities for industrial wind-tunnel applications. Particle image velocimetry (PIV) plays a leading role for particular applications (unsteady and complex flows, rotorcraft aerodynamics, turbulent separated flows) and can provide solutions that cannot be achieved with conventional techniques (e.g. in the analysis of vortex flows). This formed the main motivation to revise the state-of-the-art of PIV along with other non-intrusive optical techniques such as PSP, DGV and BOS. The two-day workshop contained sessions dedicated to several specific topics: rotorcraft aerodynamics applications; state-of-the-art of high-speed PIV and configurations for time-resolved measurements; three-dimensional PIV; non-intrusive load characterization by PSP and PIV. The main conclusion emerging from the closing discussion was that the new capabilities offered by time-resolved PIV are of great scientific and industrial interest for application to unsteady flows and in particular to the determination of unsteady aerodynamic forces and loads. We believe that this workshop provided a useful framework facilitating the transfer of new ideas from developer to the user communities. At the same time the workshop provided the upstream research community with important feedback about the areas of relevance for industrial aerodynamics.

  1. Journal of Cellular Biochemistry Supplement 39:194210 (2002) Advances in Molecular Labeling, High Throughput

    E-print Network

    Gordon, Geoffrey J.

    2002-01-01

    imaging techniques have the potential to impact cellular diagnostics for cancer screening, clinical will be achieved by advances in both instrumentation engineering (software and hardware) and molecular biochemistry. J. Cell. Biochem. Suppl. 39: 194­210, 2002. ß 2002 Wiley-Liss, Inc. Key words: microscopy; protein

  2. Application of molecular techniques on heterotrophic hydrogen production research

    Microsoft Academic Search

    R. Y. Li; T. Zhang; H. H. P. Fang

    2011-01-01

    This paper reviews the application of molecular techniques in heterotrophic hydrogen production studies. Commonly used molecular techniques are introduced briefly first, including cloning-sequencing after polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), terminal-restriction fragment length polymorphism (T-RFLP), fluorescence in situ hybridization (FISH) and quantitative real-time PCR. Application of the molecular techniques in heterotrophic hydrogen production studies are discussed in

  3. Advances in Diagnostic Techniques for Induction Machines

    Microsoft Academic Search

    Alberto Bellini; Fiorenzo Filippetti; Carla Tassoni; GÉrard-AndrÉ Capolino

    2008-01-01

    This paper investigates diagnostic techniques for electrical machines with special reference to induction machines and to papers published in the last ten years. A comprehensive list of references is reported and examined, and research activities classified into four main topics: 1) electrical faults; 2) mechanical faults; 3) signal processing for analysis and monitoring; and 4) artificial intelligence and decision-making techniques.

  4. Polyphase merge sorting: an advanced technique

    Microsoft Academic Search

    R. L. Gilstad

    1960-01-01

    Designers of generalized library sort packages for the current and future generations of computers are faced with the challenge of developing new techniques that provide more effective use of these computers. The major concern in developing efficient sorting routines in the past has been the internal sorting techniques, that is, the methods of manipulating the data within the memory of

  5. Advanced channel coding techniques using bit-level soft information 

    E-print Network

    Jiang, Jing

    2009-06-02

    In this dissertation, advanced channel decoding techniques based on bit-level soft information are studied. Two main approaches are proposed: bit-level probabilistic iterative decoding and bit-level algebraic soft-decision (list) decoding (ASD...

  6. Molecular Techniques to Assess Microbial Community Structure, Function, and Dynamics in the Environment

    Microsoft Academic Search

    Gurdeep Rastogi; Rajesh K. Sani

    \\u000a Culture-based methods are important in investigating the microbial ecology of natural and anthropogenically impacted environments,\\u000a but they are extremely biased in their evaluation of microbial genetic diversity by selecting a particular population of microorganisms.\\u000a With recent advances in genomics and sequencing technologies, microbial community analyses using culture-independent molecular\\u000a techniques have initiated a new era of microbial ecology. Molecular analyses of

  7. Multidirectional mobilities: Advanced measurement techniques and applications

    NASA Astrophysics Data System (ADS)

    Ivarsson, Lars Holger

    Today high noise-and-vibration comfort has become a quality sign of products in sectors such as the automotive industry, aircraft, components, households and manufacturing. Consequently, already in the design phase of products, tools are required to predict the final vibration and noise levels. These tools have to be applicable over a wide frequency range with sufficient accuracy. During recent decades a variety of tools have been developed such as transfer path analysis (TPA), input force estimation, substructuring, coupling by frequency response functions (FRF) and hybrid modelling. While these methods have a well-developed theoretical basis, their application combined with experimental data often suffers from a lack of information concerning rotational DOFs. In order to measure response in all 6 DOFs (including rotation), a sensor has been developed, whose special features are discussed in the thesis. This transducer simplifies the response measurements, although in practice the excitation of moments appears to be more difficult. Several excitation techniques have been developed to enable measurement of multidirectional mobilities. For rapid and simple measurement of the loaded mobility matrix, a MIMO (Multiple Input Multiple Output) technique is used. The technique has been tested and validated on several structures of different complexity. A second technique for measuring the loaded 6-by-6 mobility matrix has been developed. This technique employs a model of the excitation set-up, and with this model the mobility matrix is determined from sequential measurements. Measurements on ``real'' structures show that both techniques give results of similar quality, and both are recommended for practical use. As a further step, a technique for measuring the unloaded mobilities is presented. It employs the measured loaded mobility matrix in order to calculate compensation forces and moments, which are later applied in order to compensate for the loading of the measurement equipment. The developed measurement techniques have been used in a hybrid coupling of a plate-and-beam structure to study different aspects of the coupling technique. Results show that RDOFs are crucial and have to be included in this case. The importance of stiffness residuals when mobilities are estimated from modal superposition is demonstrated. Finally it is shown that proper curve fitting can correct errors from inconsistently measured data.

  8. 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.

  9. ADVANCED SPECTROSCOPIC AND MICRO-SCOPIC CHARACTERISATION TECHNIQUES -

    E-print Network

    Sparks, Donald L.

    - 1 - ADVANCED SPECTROSCOPIC AND MICRO- SCOPIC CHARACTERISATION TECHNIQUES - TOOLS TO ENLIGHTEN wide time scales. Ex- situ batch and flow techniques offer high elemental sensitivity, but their time-situ synchrotron-based, quick scanning X-ray absorption spectroscopy (Q-XAS) and attenuated total reflectance

  10. Advanced techniques for enhancing wireless RF transmitters' power efficiency

    Microsoft Academic Search

    Slim Boumaiza

    2008-01-01

    This paper expounds on power efficiency enhancement techniques that are sought for the reduction of power consumption of wireless radio frequency power amplifiers (RFPA) and transmitters. The paper will focus on advanced power amplification architectures such as doherty power amplifiers (DPA), linear amplification using nonlinear components (LINC), envelop elimination and restoration (EER) and envelope tracking (ET) techniques. Overview on each

  11. Recent Advances in Molecular Scale Electronics

    E-print Network

    Zhou, Chongwu

    of benzene-1,4-dithiol, which have been self-assembled onto two facing gold electrodes, has been achieved the preparation of this molecular scale wire. The formation of self-assembled monolayers (SAMs) and multilayers on gold surfaces of rigid rod conjugated oligomers that have thiol, ,-dithiol, thioacetyl

  12. Advances in molecular imaging: targeted optical contrast agents for cancer diagnostics

    PubMed Central

    Hellebust, Anne; Richards-Kortum, Rebecca

    2012-01-01

    Over the last three decades, our understanding of the molecular changes associated with cancer development and progression has advanced greatly. This has led to new cancer therapeutics targeted against specific molecular pathways; such therapies show great promise to reduce mortality, in part by enabling physicians to tailor therapy for patients based on a molecular profile of their tumor. Unfortunately, the tools for definitive cancer diagnosis – light microscopic examination of biopsied tissue stained with nonspecific dyes – remain focused on the analysis of tissue ex vivo. There is an important need for new clinical tools to support the molecular diagnosis of cancer. Optical molecular imaging is emerging as a technique to help meet this need. Targeted, optically active contrast agents can specifically label extra-and intracellular biomarkers of cancer. Optical images can be acquired in real time with high spatial resolution to image-specific molecular targets, while still providing morphologic context. This article reviews recent advances in optical molecular imaging, highlighting the advances in technology required to improve early cancer detection, guide selection of targeted therapy and rapidly evaluate therapeutic efficacy. PMID:22385200

  13. Advanced automated char image analysis techniques

    SciTech Connect

    Tao Wu; Edward Lester; Michael Cloke [University of Nottingham, Nottingham (United Kingdom). School of Chemical, Environmental and Mining Engineering

    2006-05-15

    Char morphology is an important characteristic when attempting to understand coal behavior and coal burnout. In this study, an augmented algorithm has been proposed to identify char types using image analysis. On the basis of a series of image processing steps, a char image is singled out from the whole image, which then allows the important major features of the char particle to be measured, including size, porosity, and wall thickness. The techniques for automated char image analysis have been tested against char images taken from ICCP Char Atlas as well as actual char particles derived from pyrolyzed char samples. Thirty different chars were prepared in a drop tube furnace operating at 1300{sup o}C, 1% oxygen, and 100 ms from 15 different world coals sieved into two size fractions (53-75 and 106-125 {mu}m). The results from this automated technique are comparable with those from manual analysis, and the additional detail from the automated sytem has potential use in applications such as combustion modeling systems. Obtaining highly detailed char information with automated methods has traditionally been hampered by the difficulty of automatic recognition of individual char particles. 20 refs., 10 figs., 3 tabs.

  14. 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.

  15. 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

  16. Advanced wiring technique and hardware application: Airplane and space vehicle

    NASA Technical Reports Server (NTRS)

    Ernst, H. L.; Eichman, C. D.

    1972-01-01

    An advanced wiring system is described which achieves the safety/reliability required for present and future airplane and space vehicle applications. Also, present wiring installation techniques and hardware are analyzed to establish existing problem areas. An advanced wiring system employing matrix interconnecting unit, plug to plug trunk bundles (FCC or ribbon cable) is outlined, and an installation study presented. A planned program to develop, lab test and flight test key features of these techniques and hardware as a part of the SST technology follow-on activities is discussed.

  17. Recent advances in gel-based proteome profiling techniques

    Microsoft Academic Search

    Yi Hu; Xuan Huang; Grace Y. J. Chen; Shao Q. Yao

    2004-01-01

    This review focuses on recent developments in gel-based proteomics techniques. By combining traditional sodium dodecyl sulfate-polyacrylamide\\u000a gel electrophoresis (SDS-PAGE) and two-dimensional gel electrophoretic techniques with recent advances in protein labeling\\u000a using different classes of molecules (i.e., fluorescent dyes, chemical probes, radioisotopes), new technologies have been\\u000a developed that allow for high-throughput studies of proteins at the whole-proteome scale.

  18. Advanced flip chip bonding techniques using transferred microsolder bumps

    Microsoft Academic Search

    Nobutatsu Koshoubu; Suzuko Ishizawa; Hideki Tsunetsugu; Hideyuki Takahara

    1999-01-01

    For future high-speed and high-density OE-MCM (optoelectronic multi-chip module) packaging, a technique will be needed that can bond several high-speed photonic devices and LSIs onto an OE substrate using various heat-treatment processes and can allow control of the device's position for optical alignment and high-density packaging. In the present work, we produce two advanced transferred microsolder bump bonding techniques for

  19. 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.

  20. 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.

  1. Coal and char studies by advanced EMR techniques

    SciTech Connect

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

    1999-03-31

    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 and type on water nuclear spin relaxation, T2, were measured and modeled.

  2. COAL AND COAL CONSTITUENT STUDIES BY ADVANCED EMR TECHNIQUES

    SciTech Connect

    R. Linn Belford; Robert B. Clarkson

    1997-03-28

    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 setting up a separate high frequency EMR system particularly appropriate for such studies and exploring the use of low-frequency dynamic nuclear polarization (DNP) to examine the interaction between fluids such as water and the surface of suspended char particles.

  3. Application of molecular techniques on heterotrophic hydrogen production research.

    PubMed

    Li, R Y; Zhang, T; Fang, H H P

    2011-09-01

    This paper reviews the application of molecular techniques in heterotrophic hydrogen production studies. Commonly used molecular techniques are introduced briefly first, including cloning-sequencing after polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), terminal-restriction fragment length polymorphism (T-RFLP), fluorescence in situ hybridization (FISH) and quantitative real-time PCR. Application of the molecular techniques in heterotrophic hydrogen production studies are discussed in details, focusing on identification of new isolates for hydrogen production, characterization of microbial compositions in bioreactors, monitoring microbial diversity variation, visualization of microbial distribution in hydrogen-producing granular sludge, and quantification of various microbial populations. Some significant findings in recent hydrogen production studies with the application of molecular techniques are discussed, followed by a research outlook of the heterotrophic biohydrogen field. PMID:21398117

  4. Molecular techniques: Extracting DNA from dried dots, PCR and sequencing

    E-print Network

    Schall, Joseph J.

    Molecular techniques: Extracting DNA from dried dots, PCR and sequencing Every molecular laboratory, but we are always tinkering with protocols. 1. Extracting DNA from filter paper disks. A piece of a dried results. 2. Extracting DNA from vectors. For several projects we have extracted parasite DNA from vectors

  5. Applications of molecular biology techniques to transfusion medicine

    Microsoft Academic Search

    Marion E Reid; Maria Rios; Karina Yazdanbakhsh

    2000-01-01

    Other articles in this issue of Seminars in Hematology have reviewed the results of basic research in relation to the understanding of the genes, the molecular basis of blood group variants, and structural and functional aspects of the proteins carrying blood group antigens. Although molecular techniques are currently being used in a limited fashion in clinical laboratories, their application has

  6. Advanced Groupband Data Modem Using Orthogonally Multiplexed QAM Technique

    Microsoft Academic Search

    B. Hirosaki; S. Hasegawa; A. Sabato

    1986-01-01

    An advanced groupband data modem based on the orthogonally multiplexed QAM technique is proposed. Its performance is evaluated through experiments. In the proposed modem, data are transmitted by a number of orthogonally multiplexed parallel subchannels. Because of this orthogonally multiplexing parallelism, the proposed modem becomes more immune to Gaussian noises, impulsive noises, and channel distortions, compared to the conventional Class

  7. ENGO 531: Advanced Photogrammetric and Ranging Techniques Sample Questions

    E-print Network

    Habib, Ayman

    affecting the size of the laser footprint? 5. What are the main components of a LiDAR system? 6. What and their typical values for commercial LiDAR systems: a. Scan rate/frequency, b. Pulse rate/frequency, c. GroundENGO 531: Advanced Photogrammetric and Ranging Techniques Sample Questions 1 of 2 Chapter 4: LiDAR

  8. SAE Paper 980199 Advanced Design and Validation Techniques

    E-print Network

    SAE Paper 980199 Advanced Design and Validation Techniques for Electronic Control Units Max Fuchs products. This paper presents the state-of-the-art of the design methods for the development of electronic comfort, and operational convenience in upper class automobiles requires an intensive use of electronic

  9. 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

  10. Advanced geometric techniques in 3D process simulation

    Microsoft Academic Search

    N. A. Golias; R. W. Dutton

    1996-01-01

    The modeling of semiconductor devices in the deep submicron era is a complicated and challenging procedure. Due to continuous scaling of IC structures many physical effects pose requirements for a full 3D simulation. The incorporation of advanced computational geometry techniques is imperative in the realization of such 3D process simulation tools. The simulation of a virtual factory, with the various

  11. ADVANCED TECHNIQUES FOR IMPROVING INDIRECT BRANCH PREDICTION ACCURACY

    E-print Network

    Vintan, Lucian N.

    ADVANCED TECHNIQUES FOR IMPROVING INDIRECT BRANCH PREDICTION ACCURACY Adrian Florea and Lucian N. Vintan Computer Science Department "Lucian Blaga" University of Sibiu, E. Cioran Street, No. 4, Sibiu.vintan@ulbsibiu.ro KEYWORDS Indirect branches / function calls, dynamic branch and value prediction, execution

  12. Molecular phylogeny of advanced snakes (Serpentes, Caenophidia) with an emphasis on South American Xenodontines

    E-print Network

    Murphy, Bob

    Molecular phylogeny of advanced snakes (Serpentes, Caenophidia) with an emphasis on South American a molecular phylogenetic analysis of caenophidian (advanced) snakes using sequences from two mitochondrial optimization parsimony analysis resulted in a wellresolved phylogenetic tree, which corroborates some clades

  13. Advanced Fault Diagnosis Methods in Molecular Networks

    PubMed Central

    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

  14. Molecular rotors and motors: recent advances and future challenges.

    PubMed

    Michl, Josef; Sykes, E Charles H

    2009-05-26

    At the "Molecular Rotors and Motors" symposium of the Spring 2009 ACS National Meeting in Salt Lake City (March 22-26), a diverse mix of talks addressed many current issues in the field. Speakers described topics that varied from single-molecule rotors and nanomachines to exquisite synthetic approaches toward building functional materials and mathematical and computational methods aimed at uncovering design opportunities and highlighting the fundamental limitations of molecular motors. While the realization of building useful nanomachines remains far off, a general consensus abounded that investigating biological systems and understanding the implications of the laws of thermodynamics and quantum mechanics for the behavior of nanostructures will help drive important advances in the quest for molecular machinery. Molecular rotors were demonstrated to have practical applications as probes for microviscosity, and many speakers presented experimental studies that indicated that highly directed translation and rotation of individual molecules, as well as interacting dipolar arrays, are just around the corner. While this Nano Focus is not intended to be a comprehensive review of the subject, it will focus on several key advances that were presented at the ACS meeting and highlight future challenges for the field of molecular rotors and motors. PMID:19845364

  15. Recent Advances in Molecular, Multimodal and Theranostic Ultrasound Imaging

    PubMed Central

    Kiessling, Fabian; Fokong, Stanley; Bzyl, Jessica; Lederle, Wiltrud; Palmowski, Moritz; Lammers, Twan

    2014-01-01

    Ultrasound (US) imaging is an exquisite tool for the non-invasive and real-time diagnosis of many different diseases. In this context, US contrast agents can improve lesion delineation, characterization and therapy response evaluation. US contrast agents are usually micrometer-sized gas bubbles, stabilized with soft or hard shells. By conjugating antibodies to the microbubble (MB) surface, and by incorporating diagnostic agents, drugs or nucleic acids into or onto the MB shell, molecular, multimodal and theranostic MB can be generated. We here summarize recent advances in molecular, multimodal and theranostic US imaging, and introduce concepts how such advanced MB can be generated, applied and imaged. Examples are given for their use to image and treat oncological, cardiovascular and neurological diseases. Furthermore, we discuss for which therapeutic entities incorporation into (or conjugation to) MB is meaningful, and how US-mediated MB destruction can increase their extravasation, penetration, internalization and efficacy. PMID:24316070

  16. 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.

  17. Advanced Morphological and Functional Magnetic Resonance Techniques in Glaucoma

    PubMed Central

    Mastropasqua, Rodolfo; Agnifili, Luca; Mattei, Peter A.; Caulo, Massimo; Fasanella, Vincenzo; Navarra, Riccardo; Mastropasqua, Leonardo; Marchini, Giorgio

    2015-01-01

    Glaucoma is a multifactorial disease that is the leading cause of irreversible blindness. Recent data documented that glaucoma is not limited to the retinal ganglion cells but that it also extends to the posterior visual pathway. The diagnosis is based on the presence of signs of glaucomatous optic neuropathy and consistent functional visual field alterations. Unfortunately these functional alterations often become evident when a significant amount of the nerve fibers that compose the optic nerve has been irreversibly lost. Advanced morphological and functional magnetic resonance (MR) techniques (morphometry, diffusion tensor imaging, arterial spin labeling, and functional connectivity) may provide a means for observing modifications induced by this fiber loss, within the optic nerve and the visual cortex, in an earlier stage. The aim of this systematic review was to determine if the use of these advanced MR techniques could offer the possibility of diagnosing glaucoma at an earlier stage than that currently possible.

  18. Advances Towards Integrated Biodetection Systems for Environmental Molecular Microbiology

    Microsoft Academic Search

    Darrell P. Chandler

    2002-01-01

    To overcome many of the limitations associated with indirect detection methods, new techniques for the sensitive, specific, and direct detection of nucleic acids are required in order to accurately and quantitatively ascribe phenotype\\/function to uncultivated microorganisms. However, if advanced diagnostic and detection systems are going to be applied in environmental microbiology, future \\

  19. Recent Advances in Molecular Diagnosis of Thyroid Cancer

    PubMed Central

    Legakis, Ioannis; Syrigos, Konstantinos

    2011-01-01

    Recent molecular studies have described a number of abnormalities associated with the progression and dedifferentiation of thyroid carcinoma. These distinct molecular events are often associated with specific stages of tumor development. In particular, remarkable advances have occurred in several major biological areas of thyroid cancer, including the molecular alterations for the loss of radioiodine avidity of thyroid cancer, the pathogenic role of the MAP kinase and PI3K/Akt pathways and their related genetic alterations, and the aberrant methylation of functionally important genes in thyroid tumorigenesis and pathogenesis. Recognition of these features is crucial to the management of patients with thyroid cancer. Novel treatments are being designed based on our enhanced understanding of this disease process. PMID:21603167

  20. Advanced scheduling problem using constraint programming techniques in SCM environment

    Microsoft Academic Search

    Young-Su Yun; Mitsuo Gen

    2002-01-01

    In this paper we consider a preemptive and non-preemptive scheduling model as one of the advanced scheduling problems considered by a constraint programming technique and propose a new genetic algorithm (GA) considering simultaneously the preemptive and non-preemptive cases of the activities of jobs under single machine job-shop scheduling problems. In the proposed GA, we develop a new method for representing

  1. Molecular ultrastructure of the urothelial surface: insights from a combination of various microscopic techniques.

    PubMed

    Zupan?i?, Daša; Romih, Rok; Robenek, Horst; Žužek Rožman, Kristina; Samardžija, Zoran; Kostanjšek, Rok; Kreft, Mateja Erdani

    2014-11-01

    The urothelium forms the blood-urine barrier, which depends on the complex organization of transmembrane proteins, uroplakins, in the apical plasma membrane of umbrella cells. Uroplakins compose 16 nm intramembrane particles, which are assembled into urothelial plaques. Here we present an integrated survey on the molecular ultrastructure of urothelial plaques in normal umbrella cells with advanced microscopic techniques. We analyzed the ultrastructure and performed measurements of urothelial plaques in the normal mouse urothelium. We used field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), transmission electron microscopy (TEM) on immunolabeled ultrathin sections (immuno-TEM), and freeze-fracture replicas (FRIL). We performed immunolabeling of uroplakins for scanning electron microscopy (immuno-FESEM). All microscopic techniques revealed a variability of urothelial plaque diameters ranging from 332 to 1179 nm. All immunolabeling techniques confirmed the presence of uroplakins in urothelial plaques. FRIL showed the association of uroplakins with 16 nm intramembrane particles and their organization into plaques. Using different microscopic techniques and applied qualitative and quantitative evaluation, new insights into the urothelial apical surface molecular ultrastructure have emerged and may hopefully provide a timely impulse for many ongoing studies. The combination of various microscopic techniques used in this study shows how these techniques complement one another. The described advantages and disadvantages of each technique should be considered for future studies of molecular and structural membrane specializations in other cells and tissues. PMID:25060677

  2. Stem cell systems informatics for advanced clinical biodiagnostics: tracing molecular signatures from bench to bedside.

    PubMed

    Faustino, Randolph S; Arrell, D Kent; Folmes, Clifford D L; Terzic, Andre; Perez-Terzic, Carmen

    2013-08-01

    Development of innovative high throughput technologies has enabled a variety of molecular landscapes to be interrogated with an unprecedented degree of detail. Emergence of next generation nucleotide sequencing methods, advanced proteomic techniques, and metabolic profiling approaches continue to produce a wealth of biological data that captures molecular frameworks underlying phenotype. The advent of these novel technologies has significant translational applications, as investigators can now explore molecular underpinnings of developmental states with a high degree of resolution. Application of these leading-edge techniques to patient samples has been successfully used to unmask nuanced molecular details of disease vs healthy tissue, which may provide novel targets for palliative intervention. To enhance such approaches, concomitant development of algorithms to reprogram differentiated cells in order to recapitulate pluripotent capacity offers a distinct advantage to advancing diagnostic methodology. Bioinformatic deconvolution of several "-omic" layers extracted from reprogrammed patient cells, could, in principle, provide a means by which the evolution of individual pathology can be developmentally monitored. Significant logistic challenges face current implementation of this novel paradigm of patient treatment and care, however, several of these limitations have been successfully addressed through continuous development of cutting edge in silico archiving and processing methods. Comprehensive elucidation of genomic, transcriptomic, proteomic, and metabolomic networks that define normal and pathological states, in combination with reprogrammed patient cells are thus poised to become high value resources in modern diagnosis and prognosis of patient disease. PMID:23986272

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

    PubMed Central

    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.

  4. A Brief Review of Molecular Techniques to Assess Plant Diversity

    PubMed Central

    Arif, Ibrahim A.; Bakir, Mohammad A.; Khan, Haseeb A.; Al Farhan, Ahmad H.; Al Homaidan, Ali A.; Bahkali, Ali H.; Sadoon, Mohammad Al; Shobrak, Mohammad

    2010-01-01

    Massive loss of valuable plant species in the past centuries and its adverse impact on environmental and socioeconomic values has triggered the conservation of plant resources. Appropriate identification and characterization of plant materials is essential for the successful conservation of plant resources and to ensure their sustainable use. Molecular tools developed in the past few years provide easy, less laborious means for assigning known and unknown plant taxa. These techniques answer many new evolutionary and taxonomic questions, which were not previously possible with only phenotypic methods. Molecular techniques such as DNA barcoding, random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP), microsatellites and single nucleotide polymorphisms (SNP) have recently been used for plant diversity studies. Each technique has its own advantages and limitations. These techniques differ in their resolving power to detect genetic differences, type of data they generate and their applicability to particular taxonomic levels. This review presents a basic description of different molecular techniques that can be utilized for DNA fingerprinting and molecular diversity analysis of plant species. PMID:20559503

  5. Inside Out: A Novel Labral Repair and Advancement Technique

    PubMed Central

    Mei-Dan, Omer; Pascual-Garrido, Cecilia; Kark, Jonathan A.; McConkey, Mark O.

    2014-01-01

    Labral tears are a significant cause of hip pain and are currently the most common indication for hip arthroscopy. Compared with labral debridement, labral repair has significantly better outcomes in terms of both daily activities and athletic pursuits in the setting of femoral acetabular impingement. The techniques described in the literature all use anchor placement on the capsular aspect of the acetabular rim, which can be difficult especially anteriorly, where the rim is very thin, and has the potential for significant complications. Anchor breakage, anchor slippage into the surrounding (capsular side) soft tissue, and penetration of the cartilage surface are among the most common complications. We describe an intra-articular anchor placement technique for labral repair from inside out. This technique, because of the location of the anchor and direction of suture pull, can assist in labral advancement in cases in which the native labrum fails to create a seal because of its location away from the femoral head. PMID:24904768

  6. Eliminating pharmaceutical impurities: Recent advances in detection techniques.

    PubMed

    Liu, David Q; Sun, Mingjiang; Wu, Lianming

    2010-01-01

    The elimination of organic impurities to produce highly pure drug substances is an important goal of process chemistry. For the detection of general impurities, hyphenated techniques (eg, liquid chromatography-mass spectrometry [LC-MS]) play a critical role in rapid structural identification (qualitative detection) and in understanding the mechanisms of formation of the impurities, enabling informed decisions to control and eliminate the impurities resulting from the chemical process where possible. Concern regarding genotoxic impurities (GTIs), which must typically be controlled at low parts-per-million limits, continues to increase, and significant advances have been achieved in recent years for the selective and sensitive quantitation (quantitative detection) of such impurities. Conventional detection techniques, such as ultraviolet (UV) detection, are often inadequate for the detection of potentially minute quantities of GTIs; therefore, various advanced MS-based detection strategies, either stand-alone or in conjunction with chemical approaches, are playing an increasing role in this field. The primary aim of this review is to highlight recent advances in qualitative and quantitative detection of impurities at trace levels, with a particular focus on GTIs. PMID:21061235

  7. Ayman F. HabibAdvanced Photogrammetric Techniques LiDAR Mapping

    E-print Network

    Habib, Ayman

    and diffuse. Laser Principles #12;Ayman F. HabibAdvanced Photogrammetric Techniques 8 · Laser wavelength 500DAR measurements #12;Ayman F. HabibAdvanced Photogrammetric Techniques 13 Nutating Mirror Scanning Pattern Conical

  8. 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.

  9. 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 ...

  10. Protein-Folding Dynamics: Overview of Molecular Simulation Techniques

    Microsoft Academic Search

    Harold A. Scheraga; Mey Khalili; Adam Liwo

    2007-01-01

    Molecular dynamics (MD) is an invaluable tool with which to study protein folding in silico. Although just a few years ago the dynamic behavior of a protein molecule could be simulated only in the neighborhood of the experimental conformation (or protein unfolding could be simulated at high temperature), the advent of distributed computing, new techniques such as replica-exchange MD, new

  11. PARALLEL MOLECULAR DYNAMICS TECHNIQUES FOR THE SIMULATION OF ANISOTROPIC SYSTEMS

    E-print Network

    Wilson, Mark R.

    PARALLEL MOLECULAR DYNAMICS TECHNIQUES FOR THE SIMULATION OF ANISOTROPIC SYSTEMS M. R. WILSON to parallelisation 1.1. THE NEED FOR PARALLELISM With the rapidincreases inthe speed of moderncomputers over the past few years, many people pose the question, \\why bother with parallel comput- ing?" For many researchers

  12. Efficient determination of Hugoniot states using classical molecular simulation techniques

    Microsoft Academic Search

    JOHN K. BRENNAN; BETSY M. RICE

    2003-01-01

    We present a methodology for the efficient calculation of the shock Hugoniot using standard molecular simulation techniques. The method is an extension of an equation of state methodology proposed by Erpenbeck [1992, Phys. Rev. A, 46, 6406] and is considered as an alternative to other methods that generate Hugoniot properties. We illustrate the methodology for shocked liquid N2 using two

  13. Recent Molecular Advances on Downstream Plant Responses to Abiotic Stress

    PubMed Central

    dos Reis, Sávio Pinho; Lima, Aline Medeiros; de Souza, Cláudia Regina Batista

    2012-01-01

    Abiotic stresses such as extremes of temperature and pH, high salinity and drought, comprise some of the major factors causing extensive losses to crop production worldwide. Understanding how plants respond and adapt at cellular and molecular levels to continuous environmental changes is a pre-requisite for the generation of resistant or tolerant plants to abiotic stresses. In this review we aimed to present the recent advances on mechanisms of downstream plant responses to abiotic stresses and the use of stress-related genes in the development of genetically engineered crops. PMID:22942725

  14. Modern Measurement Techniques for Testing Advanced Military Communications and Radars, 2nd Edition

    E-print Network

    Anlage, Steven

    Modern Measurement Techniques for Testing Advanced Military Communications and Radars, 2nd Edition;Modern Measurement Techniques for Testing Advanced Military Communications and Radars, 2nd Edition methods. #12;Modern Measurement Techniques for Testing Advanced Military Communications and Radars, 2nd

  15. Enhancement of PANS model's performance by introducing advanced numerical techniques

    NASA Astrophysics Data System (ADS)

    Basara, Branislav

    2008-11-01

    The Partially-Averaged Navier-Stokes (PANS) approach is a recently proposed method by Girimaji (2003), which changes seamlessly from RANS to the direct numerical solution of the Navier-Stokes equations (DNS) as the unresolved-to-total ratios of kinetic energy and dissipation are varied. The parameter which determines the unresolved-to-total kinetic energy ratio fk is defined based on the grid spacing. The PANS asymptotic behaviour goes smoothly from RANS to DNS with decreasing fk. In the work of Basara, Krajnovic and Girimaji (2008), it was shown that a dynamic update of the PANS key parameter fk by changing at each point and at the end of every time step is the promising approach to provide the optimum modeling on employed computational meshes. This work is extended here by introducing numerical techniques which efficiently increase a grid resolution and with that, decrease the parameter fk. This is achieved by employment of the effective non-reflecting boundary conditions and cutting computational domains, and by adaptive grids which allow keeping in advance prescribed value of the parameter fk. The results will show benefits of using the advanced numerical techniques in conjunction with PANS method.

  16. Recent Advances in Techniques for Hyperspectral Image Processing

    NASA Technical Reports Server (NTRS)

    Plaza, Antonio; Benediktsson, Jon Atli; Boardman, Joseph W.; Brazile, Jason; Bruzzone, Lorenzo; Camps-Valls, Gustavo; Chanussot, Jocelyn; Fauvel, Mathieu; Gamba, Paolo; Gualtieri, Anthony; Marconcini, Mattia; Tilton, James C.; Trianni, Giovanna

    2009-01-01

    Imaging spectroscopy, also known as hyperspectral imaging, has been transformed in less than 30 years from being a sparse research tool into a commodity product available to a broad user community. Currently, there is a need for standardized data processing techniques able to take into account the special properties of hyperspectral data. In this paper, we provide a seminal view on recent advances in techniques for hyperspectral image processing. Our main focus is on the design of techniques able to deal with the highdimensional nature of the data, and to integrate the spatial and spectral information. Performance of the discussed techniques is evaluated in different analysis scenarios. To satisfy time-critical constraints in specific applications, we also develop efficient parallel implementations of some of the discussed algorithms. Combined, these parts provide an excellent snapshot of the state-of-the-art in those areas, and offer a thoughtful perspective on future potentials and emerging challenges in the design of robust hyperspectral imaging algorithms

  17. Advanced IMCW Lidar Techniques for ASCENDS CO2 Column Measurements

    NASA Astrophysics Data System (ADS)

    Campbell, Joel; lin, bing; nehrir, amin; harrison, fenton; obland, michael

    2015-04-01

    Global atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity-Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud contamination. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating the need to correct for sidelobe bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These results are extended to include Richardson-Lucy deconvolution techniques to extend the resolution of the lidar beyond that implied by limit of the bandwidth of the modulation.

  18. Recent advances in molecular diagnostics of hepatitis B virus

    PubMed Central

    Datta, Sibnarayan; Chatterjee, Soumya; Veer, Vijay

    2014-01-01

    Hepatitis B virus (HBV) is one of the important global health problems today. Infection with HBV can lead to a variety of clinical manifestations including severe hepatic complications like liver cirrhosis and hepatocellular carcinoma. Presently, routine HBV screening and diagnosis is primarily based on the immuno-detection of HBV surface antigen (HBsAg). However, identification of HBV DNA positive cases, who do not have detectable HBsAg has greatly encouraged the use of nucleic acid amplification based assays, that are highly sensitive, specific and are to some extent tolerant to sequence variation. In the last few years, the field of HBV molecular diagnostics has evolved rapidly with advancements in the molecular biology tools, such as polymerase chain reaction (PCR) and real-time PCR. Recently, apart of PCR based amplification methods, a number of isothermal amplification assays, such as loop mediated isothermal amplification, transcription mediated amplification, ligase chain reaction, and rolling circle amplification have been utilized for HBV diagnosis. These assays also offer options for real time detection and integration into biosensing devices. In this manuscript, we review the molecular technologies that are presently available for HBV diagnostics, with special emphasis on isothermal amplification based technologies. We have also included the recent trends in the development of biosensors and use of next generation sequencing technologies for HBV. PMID:25356025

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

    SciTech Connect

    Iliescu, Bogdan; Haskal, Ziv J., E-mail: ziv2@mac.com [University of Maryland School of Medicine, Division of Vascular and Interventional Radiology (United States)

    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.

  20. Advanced Synchrotron Techniques at High Pressure Collaborative Access Team (HPCAT)

    NASA Astrophysics Data System (ADS)

    Shen, G.; Sinogeikin, S. V.; Chow, P.; Kono, Y.; Meng, Y.; Park, C.; Popov, D.; Rod, E.; Smith, J.; Xiao, Y.; Mao, H.

    2012-12-01

    High Pressure Collaborative Access Team (HPCAT) is dedicated to advancing cutting-edge, multidisciplinary, high-pressure science and technology using synchrotron radiation at Sector 16 of the Advanced Photon Source (APS) of Argonne National Laboratory. At HPCAT an array of novel x-ray diffraction and spectroscopic techniques has been integrated with high pressure and extreme temperature instrumentation for studies of structure and materials properties at extreme conditions.. HPCAT consists of four active independent beamlines performing a large range of various experiments at extreme conditions. 16BM-B beamline is dedicated to energy dispersive and white Laue X-ray diffraction. The majority of experiments are performed with a Paris-Edinburgh large volume press (to 7GPa and 2500K) and include amorphous and liquid structure measurement, white beam radiography, elastic sound wave velocity measurement of amorphous solid materials, with viscosity and density measurement of liquid being under development. 16BM-D is a monochromatic diffraction beamline for powder and single crystal diffraction at high pressure and high (resistive heating) / low (cryostats) temperature. The additional capabilities include high-resolution powder diffraction and x-ray absorption near edge structure (XANES) spectroscopy. The insertion device beamline of HPCAT has two undulators in canted mode (operating independently) and LN cooled Si monochromators capable of providing a large range of energies. 16IDB is a microdiffraction beamline mainly focusing on high-pressure powder and single crystal diffraction in DAC at high temperatures (double-sided laser heating and resistive heating) and low temperature (various cryostats). The modern instrumentation allows high-quality diffraction at megabar pressures from light element, fast experiments with pulsed laser heating, fast dynamic experiments with Pilatus detector, and so on. 16ID-D beamline is dedicated to x-ray scattering and spectroscopy research of materials under high pressure in DAC. The available techniques include nuclear forward scattering, nuclear resonant inelastic scattering with 2meV energy resolution for determining phonon density of state and Mössbauer effect, x-ray inelastic scattering (X-ray Raman) with 1eV energy resolution for the study of charge dynamics and chemical bonding, x-ray spectroscopy for the study of electronic excitations, X-ray emission (including partial fluorescence yield, resonant emission). Many of these measurements can be done at low temperature, with in-situ pressure measurement, or at high temperature with portable laser heating. All these advanced synchrotron techniques, as well as supporting facilities, employed at HPCAT, will be discussed.

  1. 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

  2. Recent advancement of molecular mechanisms of liver fibrosis.

    PubMed

    Seki, Ekihiro; Brenner, David A

    2015-07-01

    Liver fibrosis occurs in response to any etiology of chronic liver injury including hepatitis B and C, alcohol consumption, fatty liver disease, cholestasis, and autoimmune hepatitis. Hepatic stellate cells (HSCs) are the primary source of activated myofibroblasts that produce extracellular matrix (ECM) in the liver. Various inflammatory and fibrogenic pathways contribute to the activation of HSCs. Recent studies also discovered that liver fibrosis is reversible and activated HSCs can revert to quiescent HSCs when causative agents are removed. Although the basic research for liver fibrosis has progressed remarkably, sensitive and specific biomarkers as non-invasive diagnostic tools, and effective anti-fibrotic agents have not been developed yet. This review highlights the recent advances in cellular and molecular mechanisms of liver fibrosis, especially focusing on origin of myofibroblasts, inflammatory signaling, autophagy, cellular senescence, HSC inactivation, angiogenesis, and reversibility of liver fibrosis. PMID:25869468

  3. 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.

  4. Recent Advances in Seismic Wavefront Tracking Techniques and Their Applications

    NASA Astrophysics Data System (ADS)

    Sambridge, M.; Rawlinson, N.; Hauser, J.

    2007-12-01

    In observational seismology, wavefront tracking techniques are becoming increasingly popular as a means of predicting two point traveltimes and their associated paths. Possible applications include reflection migration, earthquake relocation and seismic tomography at a wide variety of scales. Compared with traditional ray based techniques such as shooting and bending, wavefront tracking has the advantage of locating traveltimes between the source and every point in the medium; in many cases, improved efficiency and robustness; and greater potential for tracking multiple arrivals. In this presentation, two wavefront tracking techniques will be considered: the so-called Fast Marching Method (FMM), and a wavefront construction (WFC) scheme. Over the last several years, FMM has become a mature technique in seismology, with a number of improvements to the underlying theory and the release of software tools that allow it to be used in a variety of applications. At its core, FMM is a grid based solver that implicitly tracks a propagating wavefront by seeking finite difference solutions to the eikonal equation along an evolving narrow band. Recent developments include the use of source grid refinement to improve accuracy, the introduction of a multi-stage scheme to allow reflections and refractions to be tracked in layered media, and extension to spherical coordinates. Implementation of these ideas has led to a number of different applications, including teleseismic tomography, wide-angle reflection and refraction tomography, earthquake relocation, and ambient noise imaging using surface waves. The WFC scheme represents the wavefront surface as a set of points in 6-D phase space; these points are advanced in time using local initial value ray tracing in order to form a sequence of wavefront surfaces that fill the model volume. Surface refinement and simplification techniques inspired by recent developments in computer graphics are used to maintain a fixed density of nodes as the wavefront evolves. In addition to being computationally efficient and robust, the new WFC scheme can also be used to track multi-arrivals in complex media, and thus may lead to new developments in seismic tomography.

  5. Sculpting 3D worlds with music: advanced texturing techniques

    NASA Astrophysics Data System (ADS)

    Greuel, Christian; Bolas, Mark T.; Bolas, Niko; McDowall, Ian E.

    1996-04-01

    Sound within the virtual environment is often considered to be secondary to the graphics. In a typical scenario, either audio cues are locally associated with specific 3D objects or a general aural ambiance is supplied in order to alleviate the sterility of an artificial experience. This paper discusses a completely different approach, in which cues are extracted from live or recorded music in order to create geometry and control object behaviors within a computer- generated environment. Advanced texturing techniques used to generate complex stereoscopic images are also discussed. By analyzing music for standard audio characteristics such as rhythm and frequency, information is extracted and repackaged for processing. With the Soundsculpt Toolkit, this data is mapped onto individual objects within the virtual environment, along with one or more predetermined behaviors. Mapping decisions are implemented with a user definable schedule and are based on the aesthetic requirements of directors and designers. This provides for visually active, immersive environments in which virtual objects behave in real-time correlation with the music. The resulting music-driven virtual reality opens up several possibilities for new types of artistic and entertainment experiences, such as fully immersive 3D `music videos' and interactive landscapes for live performance.

  6. Pediatric Cardiopulmonary Resuscitation: Advances in Science, Techniques, and Outcomes

    PubMed Central

    Topjian, Alexis A.; Berg, Robert A.; Nadkarni, Vinay M.

    2009-01-01

    More than 25% of children survive to hospital discharge after in-hospital cardiac arrests, and 5% to 10% survive after out-of-hospital cardiac arrests. This review of pediatric cardiopulmonary resuscitation addresses the epidemiology of pediatric cardiac arrests, mechanisms of coronary blood flow during cardiopulmonary resuscitation, the 4 phases of cardiac arrest resuscitation, appropriate interventions during each phase, special resuscitation circumstances, extracorporeal membrane oxygenation cardiopulmonary resuscitation, and quality of cardiopulmonary resuscitation. The key elements of pathophysiology that impact and match the timing, intensity, duration, and variability of the hypoxic-ischemic insult to evidence-based interventions are reviewed. Exciting discoveries in basic and applied-science laboratories are now relevant for specific subpopulations of pediatric cardiac arrest victims and circumstances (eg, ventricular fibrillation, neonates, congenital heart disease, extracorporeal cardiopulmonary resuscitation). Improving the quality of interventions is increasingly recognized as a key factor for improving outcomes. Evolving training strategies include simulation training, just-in-time and just-in-place training, and crisis-team training. The difficult issue of when to discontinue resuscitative efforts is addressed. Outcomes from pediatric cardiac arrests are improving. Advances in resuscitation science and state-of-the-art implementation techniques provide the opportunity for further improvement in outcomes among children after cardiac arrest. PMID:18977991

  7. 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...

  8. The use of molecular imaging combined with genomic techniques to understand the heterogeneity in cancer metastasis

    PubMed Central

    Chowdhury, R; Ganeshan, B; Irshad, S; Lawler, K; Eisenblätter, M; Milewicz, H; Rodriguez-Justo, M; Miles, K; Ellis, P; Groves, A; Punwani, S

    2014-01-01

    Tumour heterogeneity has, in recent times, come to play a vital role in how we understand and treat cancers; however, the clinical translation of this has lagged behind advances in research. Although significant advancements in oncological management have been made, personalized care remains an elusive goal. Inter- and intratumour heterogeneity, particularly in the clinical setting, has been difficult to quantify and therefore to treat. The histological quantification of heterogeneity of tumours can be a logistical and clinical challenge. The ability to examine not just the whole tumour but also all the molecular variations of metastatic disease in a patient is obviously difficult with current histological techniques. Advances in imaging techniques and novel applications, alongside our understanding of tumour heterogeneity, have opened up a plethora of non-invasive biomarker potential to examine tumours, their heterogeneity and the clinical translation. This review will focus on how various imaging methods that allow for quantification of metastatic tumour heterogeneity, along with the potential of developing imaging, integrated with other in vitro diagnostic approaches such as genomics and exosome analyses, have the potential role as a non-invasive biomarker for guiding the treatment algorithm. PMID:24597512

  9. 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. [Univ. of Tennessee, Knoxville, TN (United States)

    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.

  10. Photogrammetric Geo-Referencing Ayman F. HabibAdvanced Photogrammetric Techniques

    E-print Network

    Habib, Ayman

    Photogrammetric Geo-Referencing Chapter 3 Ayman F. HabibAdvanced Photogrammetric Techniques 1 #12 · Concluding Remarks Ayman F. HabibAdvanced Photogrammetric Techniques 2 Concluding Remarks #12;Notation Stands to the coordinate system denoted by a into a vector defined relative to the di d d b b a Ayman F. Habib

  11. Advanced Techniques for Modelling and Detection of Cracks in Hot Wire Steel

    Microsoft Academic Search

    Mehbub-ur RAHMAN; René MARKLEIN

    2006-01-01

    This paper presents innovative and advanced electromagnetic and ultrasonic techniques for the in-line inspection of hot wire steel. The hot wire inspection procedure is performed with two types of sensor techniques: the eddy current (EC) sensor technique and the electromagnetic ultrasonic (EMUS) sensor technique. Any type of crack on the upper surface of the steel wire disturbs the eddy current

  12. Visualizing epigenetics: current advances and advantages in HDAC PET imaging techniques

    PubMed Central

    Wang, Changning; Schroeder, Frederick A.; Hooker, Jacob M.

    2013-01-01

    Abnormal gene regulation as a consequence of flawed epigenetic mechanisms may be central to the initiation and persistence of many human diseases. However, the association of epigenetic dysfunction with disease and the development of therapeutic agents for treatment are slow. Developing new methodologies used to visualize chromatin modifying enzymes and their function in the human brain would be valuable for diagnosis of brain disorders and drug discovery. We provide an overview of current invasive and noninvasive techniques for measuring expression and functions of chromatin modifying enzymes in the brain, emphasizing tools applicable to histone deacetylase (HDAC) enzymes as a leading example. The majority of current techniques are invasive and difficult to translate to what is happening within a human brain in vivo. However, recent progress in molecular imaging provides new, noninvasive ways to visualize epigenetics in human brain. Neuroimaging tool development presents a unique set of challenges in order to identify and validate CNS radiotracers for HDACs and other histone modifying enzymes. We summarize advances in the effort to image HDACs and HDAC inhibitory effects in the brain using PET and highlight generalizable techniques that can be adapted to investigate other specific components of epigenetic machinery. Translational tools like neuroimaging by PET and MRI provide the best way to link our current understanding of epigenetic changes with in vivo function in normal and diseased brain. These tools will be a critical addition to ex vivo methods to evaluate - and intervene - in CNS dysfunction. PMID:24051365

  13. 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.

  14. Molecular genetic techniques for gene manipulation in Candida albicans

    PubMed Central

    Xu, Qiu-Rong; Yan, Lan; Lv, Quan-Zhen; Zhou, Mi; Sui, Xue; Cao, Yong-Bing; Jiang, Yuan-Ying

    2014-01-01

    Candida albicans is one of the most common fungal pathogen in humans due to its high frequency as an opportunistic and pathogenic fungus causing superficial as well as invasive infections in immunocompromised patients. An understanding of gene function in C. albicans is necessary to study the molecular basis of its pathogenesis, virulence and drug resistance. Several manipulation techniques have been used for investigation of gene function in C. albicans, including gene disruption, controlled gene expression, protein tagging, gene reintegration, and overexpression. In this review, the main cassettes containing selectable markers used for gene manipulation in C. albicans are summarized; the advantages and limitations of these cassettes are discussed concerning the influences on the target gene expression and the virulence of the mutant strains. PMID:24759671

  15. Photoionization of excited molecular states using multiphoton excitation techniques

    NASA Astrophysics Data System (ADS)

    Dehmer, P. M.; Pratt, S. T.; Dehmer, J. L.

    1984-09-01

    Photoelectron spectra are reported for three photon resonant, four photon ionization of H2 via the B 1?+u, v=7 (J=2,4) and C 1?u, v=0-4 (J=1) levels and of N2 via the o3 1?u, v=1,2, b 1?u, v=3-5, and c 1?u, v=0 levels. The results reflect both the spectroscopy and the dynamics of photoionization of excited molecular states and are discussed in terms of the selection rules for photoionization and the relative probabilities of photoionization from Rydberg and valence states. In some cases, in accordance with the Franck-Condon principle, the results demonstrate that resonant multiphoton ionization through Rydberg states may be a powerful technique for the production of electronic, vibrational, and rotational state selected ions. However, in other cases, systematic departures from Franck-Condon factors are observed, which reflect the more subtle dynamics of excited state photoionization.

  16. Modeling large RNAs and ribonucleoprotein particles using molecular mechanics techniques.

    PubMed Central

    Malhotra, A; Tan, R K; Harvey, S C

    1994-01-01

    There is a growing body of low-resolution structural data that can be utilized to devise structural models for large RNAs and ribonucleoproteins. These models are routinely built manually. We introduce an automated refinement protocol to utilize such data for building low-resolution three-dimensional models using the tools of molecular mechanics. In addition to specifying the positions of each nucleotide, the protocol provides quantitative estimates of the uncertainties in those positions, i.e., the resolution of the model. In typical applications, the resolution of the models is about 10-20 A. Our method uses reduced representations and allows us to refine three-dimensional structures of systems as big as the 16S and 23S ribosomal RNAs, which are about one to two orders of magnitude larger than nucleic acids that can be examined by traditional all-atom modeling methods. Nonatomic resolution structural data--secondary structure, chemical cross-links, chemical and enzymatic footprinting patterns, protein positions, solvent accessibility, and so on--are combined with known motifs in RNA structure to predict low-resolution models of large RNAs. These structural constraints are imposed on the RNA chain using molecular mechanics-type potential functions with parameters based on the quality of experimental data. Surface potential functions are used to incorporate shape and positional data from electron microscopy image reconstruction experiments into our models. The structures are optimized using techniques of energy refinement to get RNA folding patterns. In addition to providing a consensus model, the method finds the range of models consistent with the data, which allows quantitative evaluation of the resolution of the model. The method also identifies conflicts in the experimental data. Although our protocol is aimed at much larger RNAs, we illustrate these techniques using the tRNA structure as an example and test-bed. Images FIGURE 7 FIGURE 8 PMID:7521223

  17. Recent advances in molecular recognition based on nanoengineered platforms.

    PubMed

    Mu, Bin; Zhang, Jingqing; McNicholas, Thomas P; Reuel, Nigel F; Kruss, Sebastian; Strano, Michael S

    2014-04-15

    Nanoparticles and nanoengineered platforms have great potential for technologies involving biomoleuclar detection or cell-related biosensing, and have provided effective chemical interfaces for molecular recognition. Typically, chemists work on the modification of synthetic polymers or macromolecules, which they link to the nanoparticles by covalent or noncovalent approaches. The motivation for chemical modification is to enhance the selectivity and sensitivity, and to improve the biocompatibility for the in vivo applications. In this Account, we present recent advances in the development and application of chemical interfaces for molecular recognition for nanoparticles and nanoengineered platforms, in particular single-walled carbon nanotubes (SWNTs). We discuss emerging approaches for recognizing small molecules, glycosylated proteins, and serum biomarkers. For example, we compare and discuss detection methods for ATP, NO, H2O2, and monosaccharides for recent nanomaterials. Fluorometric detection appears to have great potential for quantifying concentration gradients and determining their location in living cells. For macromolecular detection, new methods for glycoprofiling using such interfaces appear promising, and benefit specifically from the potential elimination of cumbersome labeling and liberation steps during conventional analysis of glycans, augmenting the currently used mass spectrometry (MS), capillary electrophoresis (CE), and liquid chromatography (LC) methods. In particular, we demonstrated the great potential of fluorescent SWNTs for glycan-lectin interactions sensing. In this case, SWNTs are noncovalently functionalized to introduce a chelated nickel group. This group provides a docking site for the His-tagged lectin and acts as the signal modulator. As the nickel proximity to the SWNT surface changes, the fluorescent signal is increased or attenuated. When a free glycan or glycosylated probe interacts with the lectin, the signal increases and they are able to obtain loading curves similar to surface plasmon resonance measurements. They demonstrate the sensitivity and specificity of this platform with two higher-affined glycan-lectin pairs: fucose (Fuc) to PA-IIL and N-acetylglucosamine (GlcNAc) to GafD. Lastly, we discuss how developments in protein biomarker detection in general are benefiting specifically from label-free molecular recognition. Electrical field effect transistors, chemi-resistive and fluorometric nanosensors based on various nanomaterials have demonstrated substantial progress in recent years in addressing this challenging problem. In this Account, we compare the balance between sensitivity, selectivity, and nonspecific adsorption for various applications. In particular, our group has utilized SWNTs as fluorescence sensors for label-free protein-protein interaction measurements. In this assay, we have encapsulated each nanotube in a biocompatible polymer, chitosan, which has been further modified to conjugate nitrilotriacetic acid (NTA) groups. After Ni(2+) chelation, NTA Ni(2+) complexes bind to his-tagged proteins, resulting in a local environment change of the SWNT array, leading to optical fluorescence modulation with detection limit down to 100 nM. We have further engineered the platform to monitor single protein binding events, with an even lower detection limit down to 10 pM. PMID:24467652

  18. Performance Assessment Techniques for Teacher Career Ladder Advancement.

    ERIC Educational Resources Information Center

    Burke, Peter; Lind, Kathryn G.

    1987-01-01

    Describes the career ladder program developed for Wisconsin teachers. Includes a description of the requirements for advancement, the performance assessment component, and the different steps in the career ladder. Includes two figures. (MD)

  19. Surgical technique: new advancements for expanding indications and safety

    Microsoft Academic Search

    Guido Torzilli

    2010-01-01

    The technical issues discussed herein represent part of the panorama of innovative approaches proposed for the surgical treatment\\u000a of hepatocellular carcinoma (HCC); in particular, the attention is focused on the recent advances in the field of planning\\u000a the surgical strategy and performing liver dissection via ultrasound guidance. It is described how recent technical \\u000a advances have allowed the range of scenarios

  20. Functional characterisation of metal(loid) processes in planta through the integration of synchrotron techniques and plant molecular biology

    PubMed Central

    Donner, Erica; Punshon, Tracy; Guerinot, Mary Lou; Lombi, Enzo

    2013-01-01

    Functional characterisation of the genes regulating metal(loid) homeostasis in plants is a major focus of crop biofortification, phytoremediation, and food security research. This paper focuses on the potential for advancing plant metal(loid) research by combining molecular biology and synchrotron-based techniques. Recent advances in x-ray focussing optics and fluorescence detection have greatly improved the potential of synchrotron techniques for plant science research, allowing metal(loids) to be imaged in vivo in hydrated plant tissues at sub-micron resolution. Laterally resolved metal(loid) speciation can also be determined. By using molecular techniques to probe the location of gene expression and protein localisation and combining it with this synchrotron-derived data, functional information can be effectively and efficiently assigned to specific genes. This paper provides a review of the state of the art in this field, and provides examples as to how synchrotron-based methods can be combined with molecular techniques to facilitate functional characterisation of genes in planta. PMID:22200921

  1. 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…

  2. 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.

  3. 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.

  4. The advancing clinical impact of molecular imaging in CVD.

    PubMed

    Osborn, Eric A; Jaffer, Farouc A

    2013-12-01

    Molecular imaging seeks to unravel critical molecular and cellular events in living subjects by providing complementary biological information to current structural clinical imaging modalities. In recent years, molecular imaging efforts have marched forward into the clinical cardiovascular arena, and are now actively illuminating new biology in a broad range of conditions, including atherosclerosis, myocardial infarction, thrombosis, vasculitis, aneurysm, cardiomyopathy, and valvular disease. Development of novel molecular imaging reporters is occurring for many clinical cardiovascular imaging modalities (positron emission tomography, single-photon emission computed tomography, magnetic resonance imaging), as well as in translational platforms such as intravascular fluorescence imaging. The ability to image, track, and quantify molecular biomarkers in organs not routinely amenable to biopsy (e.g., the heart and vasculature) open new clinical opportunities to tailor therapeutics based on a cardiovascular disease molecular profile. In addition, molecular imaging is playing an increasing role in atherosclerosis drug development in phase II clinical trials. Here, we present state-of-the-art clinical cardiovascular molecular imaging strategies, and explore promising translational approaches positioned for clinical testing in the near term. PMID:24332285

  5. The Advancing Clinical Impact of Molecular Imaging in Cardiovascular Disease

    PubMed Central

    Osborn, Eric A; Jaffer, Farouc A

    2013-01-01

    Molecular imaging seeks to unravel critical molecular and cellular events in living subjects by providing complementary biological information to current structural clinical imaging modalities. In recent years, molecular imaging efforts have marched forward into the clinical cardiovascular arena, and are now actively illuminating new biology in a broad range of conditions, including atherosclerosis, myocardial infarction, thrombosis, vasculitis, aneurysm, cardiomyopathy, and valvular disease. Development of novel molecular imaging reporters is occurring for many clinical cardiovascular imaging modalities (PET, SPECT, MRI), as well in translational platforms such as intravascular fluorescence imaging. The ability to image, track, and quantify molecular biomarkers in organs not routinely amenable to biopsy (e.g. the heart and vasculature) open new clinical opportunities to tailor therapeutics based on a cardiovascular disease molecular profile. In addition, molecular imaging is playing an increasing role in atherosclerosis drug development in Phase II clinical trials. Here we present state-of-the-art clinical cardiovascular molecular imaging strategies, and explore promising translational approaches positioned for clinical testing in the near term. PMID:24332285

  6. New Strategies in Melanoma: Molecular Testing in Advanced Disease

    PubMed Central

    Woodman, Scott E.; Lazar, Alexander J.; Aldape, Kenneth D.; Davies, Michael A.

    2014-01-01

    Melanoma is one of the most aggressive forms of skin cancer. The management of melanoma is evolving rapidly due to an improved understanding of the molecular heterogeneity of this disease, and the development of effective, personalized targeted therapy strategies. While previous classification systems have been based predominantly on clinical and histologic criteria, there is now a strong rationale to add molecular markers to the diagnostic evaluation of these tumors. Research has demonstrated that the types and prevalence of genetic alterations varies between melanoma subtypes. Thus, rational molecular testing should be based on an understanding of the events likely to be present in a given tumor, and the clinical implications of testing results. This review summarizes the existing data supporting the rationale for molecular testing in clinically-defined melanoma subtypes. Emerging challenges and controversies in the use of various molecular testing platforms, and the implications of these differences for clinical testing, will also be discussed. PMID:22275506

  7. 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.

  8. Clinical application of high throughput molecular screening techniques for pharmacogenomics

    PubMed Central

    Wiita, Arun P; Schrijver, Iris

    2011-01-01

    Genetic analysis is one of the fastest-growing areas of clinical diagnostics. Fortunately, as our knowledge of clinically relevant genetic variants rapidly expands, so does our ability to detect these variants in patient samples. Increasing demand for genetic information may necessitate the use of high throughput diagnostic methods as part of clinically validated testing. Here we provide a general overview of our current and near-future abilities to perform large-scale genetic testing in the clinical laboratory. First we review in detail molecular methods used for high throughput mutation detection, including techniques able to monitor thousands of genetic variants for a single patient or to genotype a single genetic variant for thousands of patients simultaneously. These methods are analyzed in the context of pharmacogenomic testing in the clinical laboratories, with a focus on tests that are currently validated as well as those that hold strong promise for widespread clinical application in the near future. We further discuss the unique economic and clinical challenges posed by pharmacogenomic markers. Our ability to detect genetic variants frequently outstrips our ability to accurately interpret them in a clinical context, carrying implications both for test development and introduction into patient management algorithms. These complexities must be taken into account prior to the introduction of any pharmacogenomic biomarker into routine clinical testing. PMID:23226057

  9. Advanced computational techniques to simulate up-to-date automotive antenna EM\\/EMC problems

    Microsoft Academic Search

    F. G. Bogdanov; R. G. Jobava; D. D. Karkashadze; P. Tsereteli; A. L. Gheonjian; E. A. Yavolovskaya; I. Oganezova

    2010-01-01

    Based on the recent enhancements of the traditional MoM, a combined set of the advanced methods, techniques and special means is proposed to provide an accurate and effective simulation of EM\\/EMC automotive antenna problems.

  10. AN ADVANCED ENSEMBLE IMPACT MONITORING AND IDENTIFICATION TECHNIQUE FOR AEROSPACE COMPOSITE

    E-print Network

    Boyer, Edmond

    AN ADVANCED ENSEMBLE IMPACT MONITORING AND IDENTIFICATION TECHNIQUE FOR AEROSPACE COMPOSITE the small balls with the different materials and masses as the impactors. However under the various impact network, cantilever composite structure, random interfering noise 1. INTRODUCTION Aerospace structures can

  11. Reliable detection of the fungal pathogenfusarium oxysporum f.sp.albedinis, causal agent of bayoud disease of date palm, using molecular techniques

    Microsoft Academic Search

    Stanley Freeman; Marcel Maymon

    2000-01-01

    Bayoud, caused by the soilborne fungus Fusarium oxysporumf.sp. albedinis (FOA), is the most serious disease of date palm. Since the disease is located in the North African countries of Morocco and Algeria, and advancing steadily eastwards, the ultimate goal is to prevent spread of the pathogen to other date-growing areas in the region and farther afield. Molecular diagnostic techniques have

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

    Microsoft Academic Search

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

    1998-01-01

    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

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

    E-print Network

    Park, Hyunsoo

    2010-07-14

    for broader adoption of the nanoimprint technique. One of the problems is the residual layer that remains in the polymer pattern after nanoimprint. The conventional approach, oxygen reactive-ion-etching (RIE) process, to remove the residual layers, increases...

  14. Evaluation of Concurrent Error Detection Techniques on the Advanced Encryption Standard

    E-print Network

    Paris-Sud XI, Université de

    252 Evaluation of Concurrent Error Detection Techniques on the Advanced Encryption Standard K of the Advanced Encryption Standard. The protection schemes under comparison are either directly issued from Encryption Standard. Secure devices are used for storage and processing of confidential data. For that

  15. 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

  16. Advanced processing and information extraction techniques applied to ERTS-1 MSS data

    NASA Technical Reports Server (NTRS)

    Malila, W. A.; Nalepka, R. F.

    1974-01-01

    Conventional automatic data processing and information extraction techniques fall short of providing the information required by the user in some applications. For those cases, advanced techniques are needed to permit the extraction of the necessary information. Advanced techniques are described and examples of their application to ERTS-1 MSS data are provided. The techniques are designed to help overcome problems in location, mensuration, and classification accuracies which result from geometric distortions of the ERTS MSS data, the relatively coarse resolution of the sensor, and variations in atmospheric state over the region to be surveyed. It is shown that each of these factors can seriously degrade one's ability to extract necessary information. Further, it is shown that advanced techniques can alleviate the effects of these factors.

  17. Application of advanced coating techniques to rocket engine components

    NASA Technical Reports Server (NTRS)

    Verma, S. K.

    1988-01-01

    The materials problem in the space shuttle main engine (SSME) is reviewed. Potential coatings and the method of their application for improved life of SSME components are discussed. A number of advanced coatings for turbine blade components and disks are being developed and tested in a multispecimen thermal fatigue fluidized bed facility at IIT Research Institute. This facility is capable of producing severe strains of the degree present in blades and disk components of the SSME. The potential coating systems and current efforts at IITRI being taken for life extension of the SSME components are summarized.

  18. Advanced implementations of the iterative multi region technique

    NASA Astrophysics Data System (ADS)

    Kaburcuk, Fatih

    The integration of the finite-difference time-domain (FDTD) method into the iterative multi-region (IMR) technique, an iterative approach used to solve large-scale electromagnetic scattering and radiation problems, is presented in this dissertation. The idea of the IMR technique is to divide a large problem domain into smaller subregions, solve each subregion separately, and combine the solutions of subregions after introducing the effect of interaction to obtain solutions at multiple frequencies for the large domain. Solution of the subregions using the frequency domain solvers has been the preferred approach as such solutions using time domain solvers require computationally expensive bookkeeping of time signals between subregions. In this contribution we present an algorithm that makes it feasible to use the FDTD method, a time domain numerical technique, in the IMR technique to obtain solutions at a pre-specified number of frequencies in a single simulation. As a result, a considerable reduction in memory storage requirements and computation time is achieved. A hybrid method integrated into the IMR technique is also presented in this work. This hybrid method combines the desirable features of the method of moments (MoM) and the FDTD method to solve large-scale radiation problems more efficiently. The idea of this hybrid method based on the IMR technique is to divide an original problem domain into unconnected subregions and use the more appropriate method in each domain. The most prominent feature of this proposed method is to obtain solutions at multiple frequencies in a single IMR simulation by constructing time-limited waveforms. The performance of the proposed method is investigated numerically using different configurations composed of two, three, and four objects.

  19. Classification of dermatological images using advanced clustering techniques.

    PubMed

    Tasoulis, S K; Doukas, C N; Maglogiannis, I; Plagianakos, V P

    2010-01-01

    Computer vision-based diagnosis systems have been widely used in dermatology, aiming at the early detection of skin cancer and more specifically the recognition of malignant melanoma tumor. This paper proposes a novel clustering technique for the characterization and categorization of pigmented skin lesions in dermatological images. Appropriate image processing techniques (i.e. segmentation, border detection, color and texture processing) are utilized for feature extraction. The proposed method uses Principal Component Analysis and is considered appropriate, since it is suitable for problems with high dimensional data. Initial experimental results have proved the superiority of this method against traditional ones. PMID:21096085

  20. DOE`s new advanced and simplified VA technique

    SciTech Connect

    Timm, R.E. [R.E. Timm and Associates, Inc., Hinsdale, IL (United States)

    1993-12-31

    ``Experience indicates that most security systems are poorly designed and easily breached. The integrity of electronic security systems depends on the conceptual design philosophy, including a complete analysis of requirements and a thorough vulnerability assessment, prior to the selection, placement, and utilization of detection equipment.`` [Quote by the Center for Continuing Engineering Education, University of Wisconsin, Milwaukee] A new advanced vulnerability analysis model has been developed for use by security professionals who have comprehensive backgrounds in physical security. The model has been developed as an analytical tool to aid in the management, engineering design, analysis, tactical planning, and testing of security systems. It is comprised of elements that together combine to provide quantitative and qualitative evaluation of protection effectiveness. The Advanced Logic Prototype Heuristic Analysis (ALPHA) model is comprised of three basic parts: (1) an event tree logic diagram, (2) a heuristic rule base, and (3) a fuzzy set decision guide. These three parts when manipulated together, provide a top-down overview of a protection system that portrays the layers, balance, and gradation of the security system and its protection elements.

  1. In Situ Techniques for Monitoring Electrochromism: An Advanced Laboratory Experiment

    ERIC Educational Resources Information Center

    Saricayir, Hakan; Uce, Musa; Koca, Atif

    2010-01-01

    This experiment employs current technology to enhance and extend existing lab content. The basic principles of spectroscopic and electroanalytical techniques and their use in determining material properties are covered in some detail in many undergraduate chemistry programs. However, there are limited examples of laboratory experiments with in…

  2. Advances in seismic interpretation using new volume visualization techniques

    Microsoft Academic Search

    Laurent Castanie; Fabien Bosquet; Bruno Levy

    s the use of 3D seismic interpretation continues to become part of the main stream work process with the industry, visualization techniques also continue to evolve as software and hardware improves. In the past 10 years, volume rendering tools have been progres- sively adopted by the geophysical community as the emer- gence of high-end graphics workstations with 3D texture capabilities

  3. Advancements in Drying Techniques for Food, Fiber, and Fuel

    Microsoft Academic Search

    Satyanarayan R. S. Dev; Vijaya G. S. Raghavan

    2012-01-01

    Removal of moisture from biological materials, popularly called drying, has numerous benefits, including ease of handling due to reduction in bulk, resulting in reduced handling costs. Moreover, drying prevents microbial growth and spoilage. Though different drying techniques share a common objective, conceptually they are different and require modification\\/adaptation based on the biomaterial that is dried. There have been significant scientific

  4. Advanced Artificial Intelligence Techniques applied to a Motocross Game

    Microsoft Academic Search

    Benoit Chaperot; Colin Fyfe

    We have previously investigated the use of artificial neural networks to ride simulated motorbikes in a new com- puter game. These artificial neural networks were trained using two different training techniques, the Evolutionary Algorithms and the Backpropagation Algorithm. In this paper, we detail some of the investigations to improve the training, with a view to having the computer controlled bikes

  5. Recent Advances in Techniques for Hyperspectral Image Processing

    Microsoft Academic Search

    A. Plaza; J. A. Benediktsson; J. Boardman; J. Brazile; L. Bruzzone; G. Camps-Valls; J. Chanussot; M. Fauvel; P. Gamba; A. Gualtieri; M. Marconcini; J. C. Tilton; G. Trianni

    2007-01-01

    Imaging spectroscopy, also known as hyperspectral imaging, has been transformed in less than thirty years from being a sparse research tool into a commodity product available to a broad user community. Currently, there is a need for standardized data processing techniques able to take into account the special properties of hyperspec- tral data. In this paper, we provide a seminal

  6. 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.

  7. Advanced botulinum toxin techniques against wrinkles in the upper face

    Microsoft Academic Search

    Giovanni Salti; Ilaria Ghersetich

    2008-01-01

    The use of botulinum toxin type A for facial rejuvenation is one of the most common procedure in esthetic medicine. Overall clinical and study experience with botulinum toxin type A for facial enhancement has confirmed that it is effective and safe even in the long term. The different injection techniques, the starting doses, the sex, the dilution, and the storing

  8. Advances in simulation study on organic small molecular solar cells

    NASA Astrophysics Data System (ADS)

    Zhang, Xuan; Guo, Wenge; Li, Ming; Ma, Wentao; Meng, Sen

    2015-02-01

    Recently, more focuses have been put on organic semiconductors because of its advantages, such as its flexibility, ease of fabrication and potential low cost, etc. The reasons we pay highlight on small molecular photovoltaic material are its ease of purification, easy to adjust and determine structure, easy to assemble range units and get high carrier mobility, etc. Simulation study on organic small molecular solar cells before the experiment can help the researchers find relationship between the efficiency and structure parameters, properties of material, estimate the performance of the device, bring the optimization of guidance. Also, the applicability of the model used in simulation can be discussed by comparison with experimental data. This paper summaries principle, structure, progress of numerical simulation on organic small molecular solar cells.

  9. Next Generation Risk Assessment: Incorporation of Recent Advances in Molecular, Computational, and Systems Biology (External Review Draft)

    EPA Science Inventory

    EPA is releasing a draft report "Next Generation Risk Assessment: Incorporation of Recent Advances in Molecular, Computational, and Systems Biology" that explores how new molecular, computational and systems biology data and approaches (together called "NexGen") could better info...

  10. 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.

  11. Advanced Techniques in Pulmonary Function Test Analysis Interpretation and Diagnosis

    PubMed Central

    Gildea, T.J.; Bell, C. William

    1980-01-01

    The Pulmonary Functions Analysis and Diagnostic System is an advanced clinical processing system developed for use at the Pulmonary Division, Department of Medicine at the University of Nebraska Medical Center. The system generates comparative results and diagnostic impressions for a variety of routine and specialized pulmonary functions test data. Routine evaluation deals with static lung volumes, breathing mechanics, diffusing capacity, and blood gases while specialized tests include lung compliance studies, small airways dysfunction studies and dead space to tidal volume ratios. Output includes tabular results of normal vs. observed values, clinical impressions and commentary and, where indicated, a diagnostic impression. A number of pulmonary physiological and state variables are entered or sampled (A to D) with periodic status reports generated for the test supervisor. Among the various physiological variables sampled are respiratory frequency, minute ventilation, oxygen consumption, carbon dioxide production, and arterial oxygen saturation.

  12. Recent Advances in Stable Isotope Techniques for N2O Source Partitioning in Soils

    NASA Astrophysics Data System (ADS)

    Baggs, E.; Mair, L.; Mahmood, S.

    2007-12-01

    The use of 13C, 15N and 18O enables us to overcome uncertainties associated with soil C and N processes and to assess the links between species diversity and ecosystem function. Recent advances in stable isotope techniques enable determination of process rates, and are fundamental for examining interactions between C and N cycles. Here we will introduce the 15N-, 18O- and 13C-enrichment techniques we have developed to distinguish between different N2O-producing processes in situ in soils, presenting selected results, and will critically assess their potential, alone and in combination with molecular techniques, to help address key research questions for soil biogeochemistry and microbial ecology. We have developed 15N- 18O-enrichment techniques to distinguish between, and to quantify, N2O production during ammonia oxidation, nitrifier denitrification and denitrification. This provides a great advantage over natural abundance approaches as it enables quantification of N2O from each microbial source, which can be coupled with quantification of N2 production, and used to examine interactions between different processes and cycles. These approaches have also provided new insights into the N cycle and how it interacts with the C cycle. For example, we now know that ammonia oxidising bacteria significantly contribute to N2O emissions from soils, both via the traditionally accepted ammonia oxidation pathway, and also via denitrification (nitrifier denitrification) which can proceed even under aerobic conditions. We are also linking emissions from each source to diversity and activity of relevant microbial functional groups, for example through the development and application of a specific nirK primer for the nitrite reductase in ammonia oxidising bacteria. Recently, isotopomers have been proposed as an alternative for source partitioning N2O at natural abundance levels, and offers the potential to investigate N2O production from nitrate ammonification, and overcomes the need to apply 18O-H2O to determine nitrifier denitrification. However, this only provides an estimated, not a quantified, contribution, and further developments are required for quantification using isotope enrichment. Despite some limitations, such techniques become even more powerful when linked with other recent developments, such as nanoSIMS, gene expression and 13C-stable isotope probing of microbial RNA, and when linked to other disciplines. These may help address remaining questions such as: which microbes are producing N2O in soil, what is the influence of plants and mycorrhizal fungi on rhizosphere processes, and where is denitrification occurring in soil?

  13. 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.

  14. Evaluation of double-patterning techniques for advanced logic nodes

    NASA Astrophysics Data System (ADS)

    Koay, Chiew-Seng; Holmes, Steven; Petrillo, Karen; Colburn, Matthew; Burns, Sean; Dunn, Shannon; Cantone, Jason; Hetzer, David; Kawakami, Shinichiro; van Dommelen, Youri; Jiang, Aiqin; Many, Michael; Routh, Robert; Huli, Lior; Martinick, Brian; Rodgers, Martin; Tomizawa, Hideyuki; Kini, Sumanth

    2010-04-01

    The development of Double-Patterning (DP) techniques continues to push forward aiming to extend the immersion based lithography below 36 nm half pitch. There are widespread efforts to make DP viable for further scaling of semiconductor devices. We have developed Develop/Etch/Develop/Etch (DE2) and Double-Expose-Track-Optimized (DETO) techniques for producing pitch-split patterns capable of supporting semiconductor devices for the 16 nm and 11 nm nodes. The IBM Alliance has established a DETO baseline, in collaboration with ASML, TEL, CNSE, and KLATencor, to evaluate the manufacturability of DETO by using commercially available resist systems. Presented in this paper are the long-term performance results of these systems relevant to defectivity, overlay, and CD uniformity.

  15. 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.

  16. 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…

  17. 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

    Discusses small-group apprenticeships (SGAs) as a method for introducing cell culture techniques to high school participants. Teaches cell culture practices and introduces advance imaging techniques to solve various biomedical engineering problems. Clarifies and illuminates the value of small-group laboratory apprenticeships. (Author/KHR)

  18. Microwave dielectric measurements using time domain spectroscopy - Note on recent technique advances

    Microsoft Academic Search

    A. Suggett

    1975-01-01

    Use of the techniques of time domain spectroscopy (TDS) to determine the microwave properties of materials is a rapidly developing field. Two recent advances in techniques are described. Firstly, a method for reducing the uncertainty with which the time domain waveform can be referred to a common time origin which permits 'time referencing' to better than 0.08 ps-more than an

  19. An MDCT Domain Frame-Loss Concealment Technique for MPEG Advanced Audio Coding

    Microsoft Academic Search

    Sang-Uk Ryu; Kenneth Rose

    2007-01-01

    We propose a frame loss concealment technique for decoders com- patible with MPEG advanced audio coding (AAC). The spectral in- formation of the lost frame is estimated in the modified discrete co- sine transform (MDCT) domain via efficient techniques that are tai- lored to individual source signal components: In noise-like spectral bins the MDCT coefficients are obtained by shaped-noise insertion,

  20. A Review of Recent Advances in Surface Defect Detection using Texture analysis Techniques

    Microsoft Academic Search

    Xianghua Xie

    2008-01-01

    In this paper, we systematically review recent advances in surface inspection using computer vision and image processing techniques, particularly those based on texture analysis methods. The aim is to review the state-of-the-art techniques for the purposes of visual inspection and decision making schemes that are able to discriminate the features extracted from normal and defective regions. This field is so

  1. 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

  2. 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.

  3. Advances in Molecular and Cellular Therapies for Hearing Loss

    Microsoft Academic Search

    Michael S Hildebrand; Stephen S Newton; Samuel P Gubbels; Abraham M Sheffield; Amit Kochhar; Michelle G de Silva; Hans-Henrik M Dahl; Scott D Rose; Mark A Behlke; Richard JH Smith

    2008-01-01

    Development of effective therapeutics for hearing loss has proven to be a slow and difficult process, evidenced by the lack of restorative medicines and technologies currently available to the otolaryngologist. In large part this is attributable to the limited regenerative potential in cochlear cells and the secondary degeneration of the cochlear architecture that commonly follows sensorineural hearing impairment. Therapeutic advances

  4. Molecular tumor profiling: translating genomic insights into clinical advances

    Microsoft Academic Search

    Alison H Trainer

    2004-01-01

    Molecular profiling of the transcripts or proteins within an individual tumor may in future provide important prognostic and therapeutic clinical information both for the affected individual and for their extended family, but for the time being traditional genetics and pathology retain their place in the clinic.

  5. 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

  6. Recent Advances in Molecular Biology of Thyroid Cancer and Their Clinical Implications

    PubMed Central

    Xing, Mingzhao

    2009-01-01

    Synopsis Thyroid cancer is the most common endocrine malignancy with a rapid rising incidence in recent years. Novel efficient management strategies are increasingly needed for this cancer. Remarkable advances have occurred in recent years in understanding the molecular biology of thyroid cancer. This is reflected in several major biological areas of thyroid cancer, including the molecular alterations for the loss of radioiodine avidity of thyroid cancer, the pathogenic role of the MAP kinase and PI3K/Akt pathways and their related genetic alterations, and the aberrant methylation of functionally important genes in thyroid tumorigenesis and pathogenesis. These exciting advances in molecular biology of thyroid cancer provide unprecedented opportunities for the development of molecular-based novel diagnostic, prognostic, and therapeutic strategies for this cancer. PMID:19040974

  7. 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.

  8. 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

  9. Recent Advances in Spaceborne Precipitation Radar Measurement Techniques and Technology

    NASA Technical Reports Server (NTRS)

    Im, Eastwood; Durden, Stephen L.; Tanelli, Simone

    2006-01-01

    NASA is currently developing advanced instrument concepts and technologies for future spaceborne atmospheric radars, with an over-arching objective of making such instruments more capable in supporting future science needs and more cost effective. Two such examples are the Second-Generation Precipitation Radar (PR-2) and the Nexrad-In-Space (NIS). PR-2 is a 14/35-GHz dual-frequency rain radar with a deployable 5-meter, wide-swath scanned membrane antenna, a dual-polarized/dual-frequency receiver, and a realtime digital signal processor. It is intended for Low Earth Orbit (LEO) operations to provide greatly enhanced rainfall profile retrieval accuracy while consuming only a fraction of the mass of the current TRMM Precipitation Radar (PR). NIS is designed to be a 35-GHz Geostationary Earth Orbiting (GEO) radar for providing hourly monitoring of the life cycle of hurricanes and tropical storms. It uses a 35-m, spherical, lightweight membrane antenna and Doppler processing to acquire 3-dimensional information on the intensity and vertical motion of hurricane rainfall.

  10. Advances in polymer optical devices and waveguide fabrication techniques

    NASA Astrophysics Data System (ADS)

    Herman, Warren N.; Chen, Wei-Yen; Kim, Younggu; Hutchinson, Glenn; Cao, Wei Lou; Leng, Yongzhang; Yun, Victor; Liang, Hongye; Peng, Yi-Hsing; Du, Min; Lucas, Lisa; Ho, Ping-Tong; Goldhar, Julius; Lee, Chi H.

    2004-10-01

    We report progress in the development of polymer waveguides and devices for photonic applications in three areas: non-photolithographic techniques for polymer waveguide fabrication, bistability in laterally-coupled polymer microring resonators, and ultrafast photoconductive switches fabricated from semiconducting polymers. The non-photolithographic techniques for waveguide fabrication under development include laser milling with an excimer laser and programmable automatic dispensing of multimode polymer waveguides using an Essemtech automatic dispenser. Asymmetric diffraction gratings fabricated using phase masks and the interference of two excimer laser beams have exhibited concentration of optical power into the 1st diffraction order. Polymer micro-ring resonators laterally coupled to a bus line were fabricated by lithography from benzocyclobutene with radii as small as 10 ?m and free spectral ranges on the order of 20 nm. These devices exhibit bistability in the frequency domain which can arise from thermal or nonlinear optical changes in refractive index and that may have application for all-optical switching. Metal-polymer-metal switches fabricated with interdigitated electrodes in an inverted structure exhibited fast transient photoconductive pulsewidths under 20 ps in response to femtosecond pump laser pulses, but the measurement was bandwidth limited by the oscilloscope. Here we report pump-probe measurements that indicate carrier lifetimes on the order of 2 ps.

  11. 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

  12. 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...

  13. Cocoa phytochemicals: recent advances in molecular mechanisms on health.

    PubMed

    Kim, Jiyoung; Kim, Jaekyoon; Shim, Jaesung; Lee, Chang Yong; Lee, Ki Won; Lee, Hyong Joo

    2014-01-01

    Recent reports on cocoa are appealing in that a food commonly consumed for pure pleasure might also bring tangible benefits for human health. Cocoa consumption is correlated with reduced health risks of cardiovascular diseases, hypertension, atherosclerosis, and cancer, and the health-promoting effects of cocoa are mediated by cocoa-driven phytochemicals. Cocoa is rich in procyanidins, theobromine, (-)-epicatechin, catechins, and caffeine. Among the phytochemicals present in consumed cocoa, theobromine is most available in human plasma, followed by caffeine, (-)-epicatechin, catechin, and procyanidins. It has been reported that cocoa phytochemicals specifically modulate or interact with specific molecular targets linked to the pathogenesis of chronic human diseases, including cardiovascular diseases, cancer, neurodegenerative diseases, obesity, diabetes, and skin aging. This review summarizes comprehensive recent findings on the beneficial actions of cocoa-driven phytochemicals in molecular mechanisms of human health. PMID:24580540

  14. Advances in molecular detection of Aspergillus : an update

    Microsoft Academic Search

    M. Z. Abdin; Malik M. Ahmad; Saleem Javed

    2010-01-01

    Filamentous cosmopolitan fungi of the genus Aspergillus can be harmful in two ways, directly they can be opportunistic pathogens causing aspergillosis and indirectly due to aflatoxin\\u000a production on food products which can lead to aflatoxicosis. Therefore, a number of methods have been proposed so far for\\u000a detection of the fungi with lowest possible concentration at the earliest. Molecular methods such

  15. Advanced fabrication techniques for hydrogen-cooled engine structures

    NASA Technical Reports Server (NTRS)

    Buchmann, O. A.; Arefian, V. V.; Warren, H. A.; Vuigner, A. A.; Pohlman, M. J.

    1985-01-01

    Described is a program for development of coolant passage geometries, material systems, and joining processes that will produce long-life hydrogen-cooled structures for scramjet applications. Tests were performed to establish basic material properties, and samples constructed and evaluated to substantiate fabrication processes and inspection techniques. Results of the study show that the basic goal of increasing the life of hydrogen-cooled structures two orders of magnitude relative to that of the Hypersonic Research Engine can be reached with available means. Estimated life is 19000 cycles for the channels and 16000 cycles for pin-fin coolant passage configurations using Nickel 201. Additional research is required to establish the fatigue characteristics of dissimilar-metal coolant passages (Nickel 201/Inconel 718) and to investigate the embrittling effects of the hydrogen coolant.

  16. Advanced guide coating techniques for Ultra-Cold Neutron transport

    NASA Astrophysics Data System (ADS)

    Ding, Xinjian

    2012-10-01

    The UCNA experiment utilizes Ultra-Cold Neutrons (UCN) to measure angular correlations in beta-decay. UCN are produced in a solid deuterium source and then transported to the experimental decay volume through a sequence of guide tubes. Requirements for the UCNA guides include smooth surfaces, high Fermi potentials, and also a very low depolarization probability per bounce. We review the UCNA guide system and the pulsed-laser deposition process we use to produce diamond like carbon (DLC) coatings on Cu and quartz tubes. Several improvements (magnetic field shaping of the plasma plume from the laser target and better guide mounting) over previous coating techniques will be described and their effectiveness presented.

  17. Molecular heterogeneity and prognostic implications of synchronous advanced colorectal neoplasia

    PubMed Central

    Malesci, A; Basso, G; Bianchi, P; Fini, L; Grizzi, F; Celesti, G; Di Caro, G; Delconte, G; Dattola, F; Repici, A; Roncalli, M; Montorsi, M; Laghi, L

    2014-01-01

    Background: It is uncertain whether synchronous colorectal cancers (S-CRCs) preferentially develop through widespread DNA methylation and whether they have a prognosis worse than solitary CRC. As tumours with microsatellite instability (MSI) may confound the effect of S-CRC methylation on outcome, we addressed this issue in a series of CRC characterised by BRAF and MS status. Methods: Demographics, clinicopathological records and disease-specific survival (DSS) were assessed in 881 consecutively resected CRC undergoing complete colonoscopy. All tumours were typed for BRAFc.1799T>A mutation and MS status, followed by search of germ-line mutation in patients with MSI CRC. Results: Synchronous colorectal cancers (50/881, 5.7%) were associated with stage IV microsatellite-stable (MSS) CRC (19/205, 9.3%, P=0.001) and with HNPCC (9/32, 28%, P<0.001). BRAF mutation (60/881, 6.8%) was associated with sporadic MSI CRC (37/62, 60%, P<0.001) but not with S-CRC (3/50, 6.0%, P=0.96). Synchronous colorectal cancer (HR 1.82; 95% CI 1.15–2.87; P=0.01), synchronous advanced adenoma (HR 1.81; 95% CI 1.27–2.58; P=0.001), and BRAFc.1799T>A mutation (HR 2.16; 95% CI 1.25–3.73; P=0.01) were stage-independent predictors of death from MSS CRC. Disease-specific survival of MSI CRC patients was not affected by S-CRC (HR 0.74; 95% CI 0.09–5.75; P=0.77). Conclusion: Microsatellite-stable CRCs have a worse prognosis if S-CRC or synchronous advanced adenoma are diagnosed. The occurrence and the enhanced aggressiveness of synchronous MSS advanced neoplasia are not associated with BRAF mutation. PMID:24434431

  18. 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

  19. Clinical and molecular comparison between borderline serous ovarian tumors and advanced serous papillary ovarian carcinomas.

    PubMed

    Halperin, R; Zehavi, S; Dar, P; Habler, L; Hadas, E; Bukovsky, I; Schneider, D

    2001-01-01

    The aim of this study was to characterize the clinical and molecular markers of borderline serous ovarian tumors (BSOT), and to study their expression in the progression from benign lesions to advanced serous papillary ovarian carcinomas (SPOC). The clinical records of 20 patients with BSOT and 22 patients with SPOC were reviewed. Specimens from all these cases and from six benign ovarian serous cystadenomas were evaluated for expression of estrogen receptors (ER), progesterone receptors (PR), p53. HER-2/neu and Ki-67 by immunohistochemical techniques. The mean patient age and the age at menarche differed significantly between the compared groups of BSOT and SPOC (p=0.0006 and p=0.0014, respectively). No difference was observed comparing the other clinical parameters. The immunohistochemical analysis demonstrated a significant increase in the expression of ER (100% vs 72.7%), and a significant decrease in the immunoreactivity for p53 (0% vs 45.4%) and Ki-67 (2% vs 26.8%) in cases of BSOT compared with those of SPOC (p=0.007, p=0.0003 and p=0.012, respectively). No significant difference was demonstrated comparing the expression of PR and HER-2/neu. The immunostaining of benign ovarian serous cystadenoma specimens did not differ significantly from immunoreactivity observed in cases of BSOT. According to immunohistochemical analysis, BSOT had much more in common with benign serous tumors than with SPOC. The main difference between BSOT and SPOC was regarding the overexpression of p53 and Ki-67. PMID:11695812

  20. Hydrogeophysical Techniques for Site Characterization and Monitoring: Recent Advances in Ground-penetrating Radar

    Microsoft Academic Search

    Sébastien Lambot; Evert Slob; Marnik Vanclooster; Johan A. Huisman; Harry Vereecken

    \\u000a We introduce ground penetrating radar (GPR) basic principles and applications in environmental engineering, with emphasis\\u000a on quantitative methods for soil water content estimation. The main limitations of these techniques are discussed. Then, we\\u000a summarize our recent advances on the development and use of advanced off-ground GPR for shallow subsurface characterization.\\u000a The proposed method is based on full-waveform forward and inverse

  1. Observational Error Structures and the Value of Advanced Assimilation Techniques.

    NASA Astrophysics Data System (ADS)

    Swanson, K. L.; Palmer, T. N.; Vautard, R.

    2000-05-01

    The ability of four-dimensional variational (4DVAR) assimilation of data to reduce various observational error structures in a quasigeostrophic model is studied. It is found that 4DVAR with assimilation periods on the order of a week is very efficient at reducing error in phase space directions that have not amplified in the past, that is, those phase space directions that do not lie on the unstable manifold of the system. This is particularly true for observational errors that project in rapidly growing singular vector phase space directions.In general, long period 4DVAR changes the forecast error growth rates to rates similar to the leading Lyapunov exponents for the system. However, error structures that grow significantly faster than the leading Lyapunov vector and are not readily reduced by long period 4DVAR can be constructed by doing a singular vector decomposition in the subspace of growing backward Lyapunov vectors. This procedure is an approximation to calculating the singular vectors using an appropriate analysis error covariance metric for the assimilation technique. 4DVAR acting on observational errors constructed in this manner yields forecast error growth a factor of 5 larger than that of the leading Lyapunov vector over a 4-day forecast period.The addition of model error places limits on the application of long assimilation period 4DVAR. Model error adds a background level of error to the assimilated solution that cannot be reduced, and also limits how far into the past the assimilation period can be extended. These effects combine to reduce the quality of the optimal assimilated state that can obtained by applying 4DVAR. However, model error does not diminish the ability of long assimilation period 4DVAR to reduce rapidly growing singular vector-type error components. Since long assimilation periods can potentially produce large analysis errors if model error exists, the relative benefit of extending the assimilation period to reduce forecast error growth rates must be weighed in a given situation.

  2. 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.

  3. 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

  4. Advanced optical tweezers for the study of cellular and molecular biomechanics

    Microsoft Academic Search

    Gary J. Brouhard; Henry T. Schek; Alan J. Hunt

    2003-01-01

    Optical tweezers are an important tool for studying cellular and molecular biomechanics. We present a robust optical tweezers device with advanced features including: multiple optical traps, acousto-optic trap steering, and back focal plane interferometry position detection. We integrate these features into an upright microscope, with no compromise to its capabilities (differential interference contrast microscopy (DIC), fluorescence microscopy, etc.). Acousto-optic deflectors

  5. Recent advance in our understanding of the molecular nature of chromosomal abnormalities

    Microsoft Academic Search

    Hiroki Kurahashi; Hasbaira Bolor; Takema Kato; Hiroshi Kogo; Makiko Tsutsumi; Hidehito Inagaki; Tamae Ohye

    2009-01-01

    The completion of the human genome project has enabled researchers to characterize the breakpoints for various chromosomal structural abnormalities including deletions, duplications or translocations. This in turn has shed new light on the molecular mechanisms underlying the onset of gross chromosomal rearrangements. On the other hand, advances in genetic manipulation technologies for various model organisms has increased our knowledge of

  6. Bacteria and Archaea: Molecular techniques reveal astonishing diversity

    Microsoft Academic Search

    James O. McInerney; Marice Mullarkey; Martina E. Wernecke; Richard Powell

    2002-01-01

    The last decade has produced a significant advance in our appreciation of the diversity of prokaryotic organisms (commonly given the generic term “bacteria”). The need for this improvement was clear as the current list of approximately 5,000 accredited species has long been known to be a major underestimate of living prokaryotic species. The primary reasons for this poor census were

  7. Culture-independent molecular techniques for soil microbial ecology

    Microsoft Academic Search

    Penny R. Hirsch; Tim H. Mauchline; Ian M. Clark

    2010-01-01

    The advent of nucleic acid-based molecular methods, in particular the polymerase chain reaction (PCR), has revolutionised the study of soil microbial ecology, previously constrained by an inability to culture the majority of cells detected by direct microscopic observation. Extraction of DNA and RNA directly from cells in soil circumvents the requirement to grow microorganisms in laboratory culture, avoiding problems associated

  8. Stress and elastic constants in anisotropic solids: Molecular dynamics techniques

    Microsoft Academic Search

    J. F. Lutsko

    1988-01-01

    The local stress tensor commonly used in statistical mechanics is cast in a form useful for molecular dynamics (MD) simulations. It is then used to derive fluctuation formulas for the local elastic constants of a system. The formulas are used in an MD measurement of the local elastic constants of an ideal crystal which are found to be in good

  9. TECHNIQUES FOR MOLECULAR ANALYSIS Practical approaches to plant volatile analysis

    E-print Network

    Tholl, Dorothea

    plant VOCs to low-molecular and largely lipophilic products that belong to the classes of terpenes and non-terpene aliphatics (including nitrogen- and sulfur-containing compounds), phenylpropa- noids such as glandular trichomes or resin ducts (Gershenzon et al., 2000; McGarvey and Croteau, 1995) which release

  10. 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...

  11. 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.

  12. Advanced combustion techniques for controlling NO sub x emissions of high altitude cruise aircraft

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.; Reck, G. M.

    1976-01-01

    An array of experiments designed to explore the potential of advanced combustion techniques for controlling the emissions of aircraft into the upper atmosphere was discussed. Of particular concern are the oxides of nitrogen (NOx) emissions into the stratosphere. The experiments utilize a wide variety of approaches varying from advanced combustor concepts to fundamental flame tube experiments. Results are presented which indicate that substantial reductions in cruise NOx emissions should be achievable in future aircraft engines. A major NASA program is described which focuses the many fundamental experiments into a planned evolution and demonstration of the prevaporized-premixed combustion technique in a full-scale engine.

  13. Recent advances in molecular biology of parasitic viruses.

    PubMed

    Banik, Gouri Rani; Stark, Damien; Rashid, Harunor; Ellis, John T

    2015-01-01

    The numerous protozoa that can inhabit the human gastro-intestinal tract are known, yet little is understood of the viruses which infect these protozoa. The discovery, morphologic details, purification methods of virus-like particles, genome and proteome of the parasitic viruses, Entamoeba histolytica, Giardia lamblia, Trichomonas vaginalis, and the Eimeria sp. are described in this review. The protozoan viruses share many common features: most of them are RNA or double-stranded RNA viruses, ranging between 5 and 8 kilobases, and are spherical or icosahedral in shape with an average diameter of 30-40 nm. These viruses may influence the function and pathogenicity of the protozoa which they infect, and may be important to investigate from a clinical perspective. The viruses may be used as specific genetic transfection vectors for the parasites and may represent a research tool. This review provides an overview on recent advances in the field of protozoan viruses. PMID:25019235

  14. 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

  15. Molecular techniques for the investigation of meningococcal disease epidemiology

    Microsoft Academic Search

    Martin C. J. Maiden; Matthias Frosch

    2001-01-01

    Meningococcal disease remains a major cause of childhood morbidity and mortality world wide and no comprehensive vaccine is\\u000a available against the causative organism, Neisseria meningitidis. Molecular studies of the diversity of this bacterium have provided a number of key insights into its biology, which have\\u000a implications for control of meningococcal disease. These have included the identification of hyperinvasive lineages and

  16. 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.

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

    SciTech Connect

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

    1990-08-15

    This invention is comprised of 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.

  18. 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

  19. MOLECULAR ADVANCES IN AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE

    PubMed Central

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

    2010-01-01

    Autosomal dominant polycystic disease (ADPKD) is the most common form of inherited kidney disease that results renal failure. The understanding the pathogenesis of ADPKD has advanced significantly since the discovery of the two causative genes, PKD1 or 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 non-motile 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

  20. The Congenital Muscular Dystrophies: Recent Advances and Molecular Insights

    PubMed Central

    Mendell, Jerry R.; Boué, Daniel R.; Martin, Paul T.

    2010-01-01

    Over the past decade, molecular understanding of the congenital muscular dystrophies (CMDs) has greatly expanded. The diseases can be classified into 3 major groups based on the affected genes and the location of their expressed protein: abnormalities of extracellular matrix proteins (LAMA2, COL6A1, COL6A2, COL6A3), abnormalities of membrane receptors for the extracellular matrix (fukutin, POMGnT1, POMT1, POMT2, FKRP, LARGE, and ITGA7), and abnormal endoplasmic reticulum protein (SEPN1). The diseases begin in the perinatal period or shortly thereafter. A specific diagnosis can be challenging because the muscle pathology is usually not distinctive. Immunostaining of muscle using a battery of antibodies can help define a disorder that will need confirmation by gene testing. In muscle diseases with overlapping pathological features, such as CMD, careful attention to the clinical clues (e.g., family history, central nervous system features) can help guide the battery of immunostains necessary to target an unequivocal diagnosis. PMID:17163796

  1. Clinical decision support systems for brain tumor characterization using advanced magnetic resonance imaging techniques

    PubMed Central

    Tsolaki, Evangelia; Kousi, Evanthia; Svolos, Patricia; Kapsalaki, Efthychia; Theodorou, Kyriaki; Kappas, Constastine; Tsougos, Ioannis

    2014-01-01

    In recent years, advanced magnetic resonance imaging (MRI) techniques, such as magnetic resonance spectroscopy, diffusion weighted imaging, diffusion tensor imaging and perfusion weighted imaging have been used in order to resolve demanding diagnostic problems such as brain tumor characterization and grading, as these techniques offer a more detailed and non-invasive evaluation of the area under study. In the last decade a great effort has been made to import and utilize intelligent systems in the so-called clinical decision support systems (CDSS) for automatic processing, classification, evaluation and representation of MRI data in order for advanced MRI techniques to become a part of the clinical routine, since the amount of data from the aforementioned techniques has gradually increased. Hence, the purpose of the current review article is two-fold. The first is to review and evaluate the progress that has been made towards the utilization of CDSS based on data from advanced MRI techniques. The second is to analyze and propose the future work that has to be done, based on the existing problems and challenges, especially taking into account the new imaging techniques and parameters that can be introduced into intelligent systems to significantly improve their diagnostic specificity and clinical application. PMID:24778769

  2. Clinical decision support systems for brain tumor characterization using advanced magnetic resonance imaging techniques.

    PubMed

    Tsolaki, Evangelia; Kousi, Evanthia; Svolos, Patricia; Kapsalaki, Efthychia; Theodorou, Kyriaki; Kappas, Constastine; Tsougos, Ioannis

    2014-04-28

    In recent years, advanced magnetic resonance imaging (MRI) techniques, such as magnetic resonance spectroscopy, diffusion weighted imaging, diffusion tensor imaging and perfusion weighted imaging have been used in order to resolve demanding diagnostic problems such as brain tumor characterization and grading, as these techniques offer a more detailed and non-invasive evaluation of the area under study. In the last decade a great effort has been made to import and utilize intelligent systems in the so-called clinical decision support systems (CDSS) for automatic processing, classification, evaluation and representation of MRI data in order for advanced MRI techniques to become a part of the clinical routine, since the amount of data from the aforementioned techniques has gradually increased. Hence, the purpose of the current review article is two-fold. The first is to review and evaluate the progress that has been made towards the utilization of CDSS based on data from advanced MRI techniques. The second is to analyze and propose the future work that has to be done, based on the existing problems and challenges, especially taking into account the new imaging techniques and parameters that can be introduced into intelligent systems to significantly improve their diagnostic specificity and clinical application. PMID:24778769

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

    PubMed

    Acevedo, Orlando; Jorgensen, Wiliiam L

    2014-09-01

    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

  4. 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.

  5. Advanced Signal Processing Techniques for Fault Detection and Diagnosis in a Wind Turbine

    E-print Network

    Paris-Sud XI, Université de

    Advanced Signal Processing Techniques for Fault Detection and Diagnosis in a Wind Turbine Induction rotor bars and bearing damages. Index Terms--Wind turbines, motor current signature analy- sis, time of maintenance in offshore environment, teledetection of wind turbine faults is becoming a crucial issue

  6. Urban Wastewater Reclamation and Reuse Advanced Techniques: Novel Membrane BioReactor Technology

    Microsoft Academic Search

    Zhiqiang Wang; Huichuan Zhang; Li Tian; Lei Liu

    2011-01-01

    The study on municipal wastewater reclamation technology is increasingly urged to develop for the lack of water resource and water environmental pollution. As an advanced wastewater treatment technique, membrane bio-reactor was deeply studied and applied recently, but the application of MBR in municipal wastewater reclamation and the membrane fouling were not resolved well till now. The combination of air and

  7. ADVANCED MOTION COMPENSATION TECHNIQUES FOR BLOCKING ARTIFACTS REDUCTION IN 3-D VIDEO CODING SYSTEMS

    E-print Network

    Shen, Zuowei

    ADVANCED MOTION COMPENSATION TECHNIQUES FOR BLOCKING ARTIFACTS REDUCTION IN 3-D VIDEO CODING compensation model to reduce blocking artifacts in a highly scalable video coding system. Previous works have compensation (OBMC) to reduce blocking artifacts. However, both methods generate distinct side effects

  8. Removal of selected pharmaceuticals from sewage water by advanced treatment techniques

    Microsoft Academic Search

    René Wetzig

    The presence of pharmaceuticals as trace pollutants in natural surface water bodies, ground water and drinking water has recently led to some concern. Since sewage is the main source of this type of pollution, some attempts have been made to remove pharmaceuticals by advanced physical, chemical and biological techniques which go further than the conventional treatment. A few of these

  9. Evaluation of Testing Techniques for the losipescu Shear Test for Advanced Composite Materials

    Microsoft Academic Search

    S. Lee; M. Munro

    1990-01-01

    The purpose of the study was to explore and subsequently establish ex perimental techniques for the losipescu shear test method for advanced composite materials. For the preparation of notches in the Iosipescu specimens it was found that con ventional machine cutting tools could be used provided that the base of the notch was in spected for micro-damage. The occurrence of

  10. 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.

  11. PDE Estimation Techniques for Advanced Battery Management Systems -Part I: SOC Estimation

    E-print Network

    Krstic, Miroslav

    PDE Estimation Techniques for Advanced Battery Management Systems - Part I: SOC Estimation S. J examine a new battery state-of-charge (SOC) estimation algorithm based upon the backstepping method This paper investigates a Li-ion battery state-of-charge (SOC) estimation algorithm based upon

  12. Recent advances in hantavirus molecular biology and disease.

    PubMed

    Hussein, Islam T M; Haseeb, Abdul; Haque, Absarul; Mir, Mohammad A

    2011-01-01

    Hantaviruses are emerging zoonotic pathogens that belong to the Bunyaviridae family. They have been classified as category A pathogens by CDC (centers for disease control and prevention). Hantaviruses pose a serious threat to human health because their infection causes two highly fatal diseases, hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS). These pathogens are transmitted to humans through aerosolized excreta of their infected rodent hosts. Hantaviruses have a tripartite-segmented negative-sense RNA genome. The three genomic RNA segments, S, M, and L, encode a nucleocapsid protein (N), a precursor glycoprotein that is processed into two envelope glycoproteins (Gn and Gc) and the viral RNA-dependent RNA polymerase (RdRp), respectively. N protein is the major structural component of the virus, its main function is to protect and encapsidate the three genomic RNAs forming three viral ribonucleocapsids. Recent studies have proposed that N in conjunction with RdRp plays important roles in the transcription and replication of viral genome. In addition, N preferentially facilitates the translation of viral mRNA in cells. Glycoproteins, Gn and Gc, play major roles in viral attachment and entry to the host cells, virulence, and assembly and packaging of new virions in infected cells. RdRp functions as RNA replicase and transcriptase to replicate and transcribe the viral RNA and is also thought to have endonuclease activity. Currently, no antiviral therapy or vaccine is available for the treatment of hantavirus-associated diseases. Understanding the molecular details of hantavirus life cycle will help in the identification of targets for antiviral therapeutics and in the design of potential antiviral drug for the treatment of HFRS and HCPS. Due to the alarming fatality of hantavirus diseases, development of an effective vaccine against hantaviruses is a necessity. PMID:21459193

  13. MR techniques for in vivo molecular and cellular imaging.

    PubMed

    Delikatny, Edward J; Poptani, Harish

    2005-01-01

    MR-based molecular imaging is a science in infancy. Current clinical contrast agents are often geared toward the assessment of gross physiologic function, rather than targeting specific biochemical pathways. The development of specific targeted smart contrast agents for Food and Drug Administration approval or clinical trials has only begun. The fact that MR imaging can obtain images of extremely high resolution, coupled with its ability to simultaneously assess structure and function through the use of targeted contrast agents indicates that MR will play a pivotal role in clinical molecular imaging of the future. Many of the challenges that face MR imaging and spectroscopy are inherent to all modalities in the rapidly growing field of molecular imaging. The development of smart contrast agents to report on receptor function, and to monitor gene expression or the results of gene therapy in humans is paramount. These compounds need to undergo rigorous testing to be approved for clinical use: the assessment of acute toxicity, pharmacokinetics, long-term accumulation, and subsequent chronic effects. For receptor-targeted contrast agents, the degree of receptor occupancy and the intrinsic agonist or antagonist properties of the probe that may affect normal cellular function need to be determined to avoid undesired side effects. The particular problems that face MR imaging, those of sensitivity and target specificity, need to be overcome. Signal amplification achieved through high relaxivity contrast agents containing multiple paramagnetic centers, or of larger superparamagnetic particles, is the first step in this direction. The modulation of relaxivity through oligomerization, or other modifications that cause restriction of rotational motions, shows great promise for improving the discriminative powers of MR imaging, and may permit multiple targets to be assessed simultaneously. Moreover, the introduction of smart indicators that lead to changes in spectroscopic properties will allow further discrimination to be achieved through the implementation of chemical shift or spectroscopic imaging. The growing number of MR imaging applications in this rapidly expanding field point to a bright future for MR imaging in molecular imaging. PMID:15693657

  14. Optimization techniques in molecular structure and function elucidation

    PubMed Central

    Sahinidis, Nikolaos V.

    2009-01-01

    This paper discusses recent optimization approaches to the protein side-chain prediction problem, protein structural alignment, and molecular structure determination from X-ray diffraction measurements. The machinery employed to solve these problems has included algorithms from linear programming, dynamic programming, combinatorial optimization, and mixed-integer nonlinear programming. Many of these problems are purely continuous in nature. Yet, to this date, they have been approached mostly via combinatorial optimization algorithms that are applied to discrete approximations. The main purpose of the paper is to offer an introduction and motivate further systems approaches to these problems. PMID:20160866

  15. Chronic phase advance alters circadian physiological rhythms and peripheral molecular clocks.

    PubMed

    Wolff, Gretchen; Duncan, Marilyn J; Esser, Karyn A

    2013-08-01

    Shifting the onset of light, acutely or chronically, can profoundly affect responses to infection, tumor progression, development of metabolic disease, and mortality in mammals. To date, the majority of phase-shifting studies have focused on acute exposure to a shift in the timing of the light cycle, whereas the consequences of chronic phase shifts alone on molecular rhythms in peripheral tissues such as skeletal muscle have not been studied. In this study, we tested the effect of chronic phase advance on the molecular clock mechanism in two phenotypically different skeletal muscles. The phase advance protocol (CPA) involved 6-h phase advances (earlier light onset) every 4 days for 8 wk. Analysis of the molecular clock, via bioluminescence recording, in the soleus and flexor digitorum brevis (FDB) muscles and lung demonstrated that CPA advanced the phase of the rhythm when studied immediately after CPA. However, if the mice were placed into free-running conditions (DD) for 2 wk after CPA, the molecular clock was not phase shifted in the two muscles but was still shifted in the lung. Wheel running behavior remained rhythmic in CPA mice; however, the endogenous period length of the free-running rhythm was significantly shorter than that of control mice. Core body temperature, cage activity, and heart rate remained rhythmic throughout the experiment, although the onset of the rhythms was significantly delayed with CPA. These results provide clues that lifestyles associated with chronic environmental desynchrony, such as shift work, can have disruptive effects on the molecular clock mechanism in peripheral tissues, including both types of skeletal muscle. Whether this can contribute, long term, to increased incidence of insulin resistance/metabolic disease requires further study. PMID:23703115

  16. Molecular beam epitaxy for advanced gate stack materials and processes

    NASA Astrophysics Data System (ADS)

    Locquet, Jean-Pierre

    2005-03-01

    The material requirements for future CMOS generations - as given by the ITRS roadmap - are very challenging. This includes a high K dielectric without a low K interfacial layer, a high mobility channel and the appropriate metal gate. With the help of two projects INVEST and ET4US, we are building up a molecular beam epitaxy (MBE) infrastructure to grow this material set on large area wafers that can be further processed into small scale devices. In the INVEST project, we have developed an MBE system for the growth of complex oxides on semiconductors. The system follows the overall design of a production tool and is equipped with an RF atomic oxygen source, effusion cells, e-beam evaporators and a differential pumping stage. The oxide growth process starts with desorbing the initial surface oxide on the Si wafers in ultra-high vacuum and high temperature to create a clean reconstructed 2x1 surface. Using the atomic oxygen it is possible to oxidize the surface in a well controlled manner at low temperature and to grow very thin and dense SiOx layers, followed by the growth of 2-6 nm amorphous high K dielectrics. The process parameters permit to tune the interface layer from a SiOx rich to a silicide rich interface with a significant impact on the capacitance and the leakage. Initial focus is on developing an optimized growth recipe for high quality amorphous HfO2 and LaHfO3.5 films. This recipe was subsequently used to make wafers for a transistor batch that gave us the first N short channel MBE MOSFET's (100 nm) using an etched gate process flow. Some highlights of the first batch for 3nm HfO2 MOSFET are a high mobility (> 270 cm^2/Vs) with a corresponding low leakage current of 2 mA/cm^2). While there were some process issues for LaHfO3.5, the 3 nm MOSFET showed very low leakage currents below 10-6 A/cm^2. Interestingly all the LaHFO3.5 MOSFETs showed very low threshold voltage instabilities. In collaboration with C. Marchiori, M. Sousa, A.Guiller, H. Siegwart, D. Caimi, J. Fompeyrine, D. J Webb, C. Rossel, R. Germann of IBM Research GmbH Zurich Switzerland; L. Pantisano, M. Claes, T. Conard, M. Demand, W. Deweerd, S. DeGendt, M. Heyns, M. Houssa, M. Aoulaiche, G. Lujan, L. Ragnarsson, E. Rohr, T. Schram of IMEC Leuven Belgium; J. Hooker, Z.M Rittersma, Y. Furukawa of Philips Research Leuven Belgium and J. W. Seo of EPFL Lausanne Switzerland.

  17. Advance of Molecular Imaging Technology and Targeted Imaging Agent in Imaging and Therapy

    PubMed Central

    Chen, Zhi-Yi; Wang, Yi-Xiang; Lin, Yan; Zhang, Jin-Shan; Yang, Feng; Zhou, Qiu-Lan; Liao, Yang-Ying

    2014-01-01

    Molecular imaging is an emerging field that integrates advanced imaging technology with cellular and molecular biology. It can realize noninvasive and real time visualization, measurement of physiological or pathological process in the living organism at the cellular and molecular level, providing an effective method of information acquiring for diagnosis, therapy, and drug development and evaluating treatment of efficacy. Molecular imaging requires high resolution and high sensitive instruments and specific imaging agents that link the imaging signal with molecular event. Recently, the application of new emerging chemical technology and nanotechnology has stimulated the development of imaging agents. Nanoparticles modified with small molecule, peptide, antibody, and aptamer have been extensively applied for preclinical studies. Therapeutic drug or gene is incorporated into nanoparticles to construct multifunctional imaging agents which allow for theranostic applications. In this review, we will discuss the characteristics of molecular imaging, the novel imaging agent including targeted imaging agent and multifunctional imaging agent, as well as cite some examples of their application in molecular imaging and therapy. PMID:24689058

  18. 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.

  19. Reliable detection of the fungal pathogen fusarium oxysporum f.sp. albedinis , causal agent of bayoud disease of date palm, using molecular techniques

    Microsoft Academic Search

    Stanley Freeman; Marcel Maymon

    2000-01-01

    Bayoud, caused by the soilborne fungusFusarium oxysporum f.sp.albedinis (FOA), is the most serious disease of date palm. Since the disease is located in the North African countries of Morocco and\\u000a Algeria, and advancing steadily eastwards, the ultimate goal is to prevent spread of the pathogen to other date-growing areas\\u000a in the region and farther afield. Molecular diagnostic techniques have been

  20. 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.

  1. Probing Molecular Dynamics with Non-linear Optical Techniques

    NASA Astrophysics Data System (ADS)

    Lausten, Rune

    The dynamics of molecules in the gas and liquid phase is investigated using ultrafast optical techniques. The development of sub-25 fs ultrafast sources using noncollinear optical parametric amplification is discussed. These intense pulses are utilized in coherent anti-Stokes Raman scattering to investigate vibrational motion in I2 Br2 and IBr. For larger bio-molecules relevant dynamics may not be related to the absorption of light. Here, a new technique is introduced, in which an optically excitable molecule is incorporated into the bio-molecule. Photoisomerization of the trigger molecule initiates structural rearrangement in the larger system. To demonstrate this approach, azobenzene was synthesized into short strands of DNA to time-resolve base pair destacking dynamics and DNA melting. The isomerization of azobenzene in thin polymer films (and their corresponding change in optical properties) was also used to write birefringence and surface relief gratings. This method was used to demonstrate a rewritable Bragg filter for telecom wavelengths. Lastly, an alternative to typical crystal based wavemixing is presented for the generation of ultrafast tunable ultraviolet and deep ultraviolet pulses. The approach utilizes difference frequency four wave mixing in hollow waveguides filled with noble gas.

  2. 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).

  3. 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.

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

    SciTech Connect

    NONE

    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.

  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. Advanced digital modulation: Communication techniques and monolithic GaAs technology

    NASA Technical Reports Server (NTRS)

    Wilson, S. G.; Oliver, J. D., Jr.; Kot, R. C.; Richards, C. R.

    1983-01-01

    Communications theory and practice are merged with state-of-the-art technology in IC fabrication, especially monolithic GaAs technology, to examine the general feasibility of a number of advanced technology digital transmission systems. Satellite-channel models with (1) superior throughput, perhaps 2 Gbps; (2) attractive weight and cost; and (3) high RF power and spectrum efficiency are discussed. Transmission techniques possessing reasonably simple architectures capable of monolithic fabrication at high speeds were surveyed. This included a review of amplitude/phase shift keying (APSK) techniques and the continuous-phase-modulation (CPM) methods, of which MSK represents the simplest case.

  7. [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

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

    SciTech Connect

    Holtom, Gary R. (BATTELLE (PACIFIC NW LAB)); Thrall, Brian D. (BATTELLE (PACIFIC NW LAB)); Chin, Beek Yoke (BATTELLE (PACIFIC NW LAB)); Wiley, H Steven (BATTELLE (PACIFIC NW LAB)); Colson, Steven D. (BATTELLE (PACIFIC NW LAB))

    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.

  9. 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.

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

    PubMed

    Lu, Feng-Mei; Yuan, Zhen

    2015-06-01

    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

  11. 'Boomerang' technique: an improved method for conformal treatment of locally advanced nasopharyngeal cancer.

    PubMed

    Corry, June; Hornby, Colin; Fisher, Richard; D'Costa, Ieta; Porceddu, Sandro; Rischin, Danny; Peters, Lester J

    2004-06-01

    The primary aim of the present study was to assess radiation dosimetry and subsequent clinical outcomes in patients with locally advanced nasopharyngeal cancer using a novel radiation technique termed the 'Boomerang'. Dosimetric comparisons were made with both conventional and intensity modulated radiation therapy (IMRT) techniques. This is a study of 22 patients treated with this technique from June 1995 to October 1998. The technique used entailed delivery of 36 Gy in 18 fractions via parallel opposed fields, then 24 Gy in 12 fractions via asymmetric rotating arc fields for a total of 60 Gy in 30 fractions. Patients also received induction and concurrent chemotherapy. The radiation dosimetry was excellent. Dose-volume histograms showed that with the arc fields, 90% of the planning target volume received 94% of the prescribed dose. Relative to other conventional radiation therapy off-cord techniques, the Boomerang technique results in a 27% greater proportion of the prescribed dose being received by 90% of the planning target volume. This translates into an overall 10% greater dose received for the same prescribed dose. At 3 years, the actuarial loco-regional control rate, the failure-free survival rate and the overall survival rate were 91, 75 and 91%, respectively. At 5 years, the actuarial loco-regional control rate, the failure-free survival rate and the overall survival rate were 74, 62 and 71%, respectively. The Boomerang technique provided excellent radiation dosimetry with correspondingly good loco-regional control rates (in conjunction with chemotherapy) and very acceptable acute and late toxicity profiles. Because treatment can be delivered with conventional standard treatment planning and delivery systems, it is a validated treatment option for centres that do not have the capability or capacity for IMRT. A derivative of the Boomerang technique, excluding the parallel opposed component, is now our standard for patients with locally advanced nasopharyngeal cancer when IMRT is not available. PMID:15230751

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

    SciTech Connect

    Groppo, J.G.; Parekh, B.K. [Univ. of Kentucky, Lexington, KY (United States); Rawls, P. [Department of Energy, Pittsburgh, PA (United States)

    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.

  13. 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

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

    SciTech Connect

    DiMaio, Frank, E-mail: dimaio@u.washington.edu [University of Washington, UW Box 357350, Seattle, WA 98195 (United States)

    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.

  15. [Application of modern molecular biology techniques to study micro-ecosystem in the rumen].

    PubMed

    Duan, Zhi-yong; Guo, Yan-qiu; Liu, Jian-xin

    2006-02-01

    The microbial community inhabiting in the rumen is characterized by its high population density, wide diversity and interactive complexity. However, until recently our knowledge of rumen microbiology was primarily based on classical culture based techniques (isolation, enumeration and nutritional characterization) which probably only account for 10% to 20% of the rumen microbial population. Modem molecular biology techniques provide effective methods to study the micro-ecosystem in the rumen. The use of molecular techniques based on nucleic acid probes is likely to revolutionize the approach to microbial ecology in the rumen and provide, not simply a refinement or increased understanding but a complete description of rumen community for the first time. Modem molecular techniques based on sequence comparisons of nucleic acids may be used to explore molecular characterization and provide a classification scheme which predicts natural evolutionary relationships. Genetic fingerprinting techniques that provide a pattern or profile of genetic diversity have been applied in a variety of environmental studies for the analysis of microbial communities. Whole-cell hybridization is a powerful technique which may be used to study the structure and function of microbial communities in situ and describe the expression of key enzymes. Real-time quantitative PCR technique may be conducted to accurately quantify the target microorganisms in the rumen. Development of these procedures and techniques will result in greater insights into community structure and activity of rumen microbial communities in relation to functional interactions, spatial and temporal relationships between different microorganisms and between microorganisms and feed particles. The successful development and application of these methods promise to provide the first opportunity to link distribution and identity of rumen microbes in their natural environment with their genetic potential and in situ activities. PMID:16579489

  16. Protein NMR Techniques, 3rd Methods in Molecular Biology, Springer Verlag (Humana Press), 2011

    E-print Network

    Linsley, Braddock K.

    Protein NMR Techniques, 3rd ed. Methods in Molecular Biology, Springer Verlag (Humana Press), 2011, 518 pages. The field of protein NMR spectroscopy has rapidly expanded into new areas of biochemistry of the latest innovations in the field of protein NMR. It focuses on the application of NMR to biochemistry

  17. Molecular techniques in the biotechnological fight against halogenated compounds in anoxic environments

    PubMed Central

    Ding, Chang; He, Jianzhong

    2012-01-01

    Summary Microbial treatment of environmental contamination by anthropogenic halogenated organic compounds has become popular in recent decades, especially in the subsurface environments. Molecular techniques such as polymerase chain reaction?based fingerprinting methods have been extensively used to closely monitor the presence and activities of dehalogenating microbes, which also lead to the discovery of new dehalogenating bacteria and novel functional genes. Nowadays, traditional molecular techniques are being further developed and optimized for higher sensitivity, specificity, and accuracy to better fit the contexts of dehalogenation. On the other hand, newly developed high throughput techniques, such as microarray and next?generation sequencing, provide unsurpassed detection ability, which has enabled large?scale comparative genomic and whole?genome transcriptomic analysis. The aim of this review is to summarize applications of various molecular tools in the field of microbially mediated dehalogenation of various halogenated organic compounds. It is expected that traditional molecular techniques and nucleic?acid?based biomarkers will still be favoured in the foreseeable future because of relative low costs and high flexibility. Collective analyses of metagenomic sequencing data are still in need of information from individual dehalogenating strains and functional reductive dehalogenase genes in order to draw reliable conclusions. PMID:22070763

  18. 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.

  19. 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 rate 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.

  20. Nanopositioning techniques development for synchrotron radiation instrumentation applications at the Advanced Photon Source

    SciTech Connect

    Shu Deming [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2010-06-23

    At modern synchrotron radiation sources and beamlines, high-precision positioning techniques present a significant opportunity to support state-of-the-art synchrotron radiation research. Meanwhile, the required instrument positioning performance and capabilities, such as resolution, dynamic range, repeatability, speed, and multiple axes synchronization are exceeding the limit of commercial availability. This paper presents the current nanopositioning techniques developed for the Argonne Center for Nanoscale Materials (CNM)/Advanced Photon Source (APS) hard x-ray nanoprobe and high-resolution x-ray monochromators and analyzers for the APS X-ray Operations and Research (XOR) beamlines. Future nanopositioning techniques to be developed for the APS renewal project will also be discussed.

  1. 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.

  2. Local analysis technique for the Advanced Neutron Source Reactor fuel defect studies

    SciTech Connect

    Giles, G.E. Jr. [Oak Ridge National Lab., TN (United States)

    1997-03-01

    The safety analysis for the Advanced Neutron Source Reactor (ANSR) required the development of a new analysis technique to determine fuel integrity and to assure avoidance of critical heat flux (CHF) conditions. The ANSR is a research reactor design intended to provide the highest continuous neutron beam intensity of any reactor in the world. Reliance on previous safety analysis techniques such as those used in the High Flux Isotope Reactor would result in a design that would not meet the requirements. A more accurate but still conservative analysis technique was developed for the ANSR safety analyses. This technique, the local analysis technique (LAT), relaxed some of the overly conservative assumptions of previous hot-spot studies by using a large number of detailed analyses. The conditions used in these analyses were spread over the possible distributions found in specific designs. This technique was used to analyze several core designs to produce confidence in the fuel plate integrity that could be damaged by excessive fuel temperatures and avoidance of CHF conditions. This approach can be used for other reactor designs and should allow increases in the operating power levels. Alternatively, the LAT could be used to demonstrate increased safety margins for present operating conditions.

  3. Molecular entomology and prospects for malaria control

    Microsoft Academic Search

    Frank H. Collins; Luna Kamau; Hilary A. Ranson; John M. Vulule

    2000-01-01

    During the past decade, the techniques of molecular and cell biology have been embraced by many scientists doing research on anopheline vectors of malaria parasites. Some of the most important research advances in molecular entomology have concerned the development of sophisticated molecular tools for procedures such as genetic and physical mapping and germ line transformation. Major advances have also been

  4. New strategies in ovarian cancer: translating the molecular complexity of ovarian cancer into treatment advances.

    PubMed

    Liu, Joyce; Matulonis, Ursula A

    2014-10-15

    An improved understanding of the genomics of ovarian cancer and the separation of ovarian cancer into histologically and molecularly defined subgroups have affected drug development and clinical trial design in ovarian cancer. Active therapies that have been tested in ovarian cancer include agents that inhibit angiogenesis and poly (ADP-ribose) polymerase inhibitors (PARPi). However, no FDA drug approvals for ovarian cancer have been granted since 2006, and overall survival improvements have been difficult to achieve with new agents. The genomic complexity of ovarian cancer and modest single-agent activity of many biologic agents in this disease have led to testing of biologic agent combinations. In this article, we review recent advances in the understanding of the molecular diversity of ovarian cancer as well as emerging therapeutic strategies such as new agents and biologic combinations that attempt to target multiple aberrant pathways in this cancer. PMID:25320365

  5. 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.

  6. 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.

  7. Techniques for measurement of the thermal expansion of advanced composite materials

    NASA Technical Reports Server (NTRS)

    Tompkins, Stephen S.

    1989-01-01

    Techniques available to measure small thermal displacements in flat laminates and structural tubular elements of advanced composite materials are described. Emphasis is placed on laser interferometry and the laser interferometric dilatometer system used at the National Aeronautics and Space Administration (NASA) Langley Research Center. Thermal expansion data are presented for graphite-fiber reinforced 6061 and 2024 aluminum laminates and for graphite fiber reinforced AZ91 C and QH21 A magnesium laminates before and after processing to minimize or eliminate thermal strain hysteresis. Data are also presented on the effects of reinforcement volume content on thermal expansion of silicon-carbide whisker and particulate reinforced aluminum.

  8. Molecular Techniques for Detection, Species Differentiation, and Phylogenetic Analysis of Microsporidia

    PubMed Central

    Franzen, Caspar; Müller, Andreas

    1999-01-01

    Microsporidia are obligate intracellular protozoan parasites that infect a broad range of vertebrates and invertebrates. These parasites are now recognized as one of the most common pathogens in human immunodeficiency virus-infected patients. For most patients with infectious diseases, microbiological isolation and identification techniques offer the most rapid and specific determination of the etiologic agent. This is not a suitable procedure for microsporidia, which are obligate intracellular parasites requiring cell culture systems for growth. Therefore, the diagnosis of microsporidiosis currently depends on morphological demonstration of the organisms themselves. Although the diagnosis of microsporidiosis and identification of microsporidia by light microscopy have greatly improved during the last few years, species differentiation by these techniques is usually impossible and transmission electron microscopy may be necessary. Immunfluorescent-staining techniques have been developed for species differentiation of microsporidia, but the antibodies used in these procedures are available only at research laboratories at present. During the last 10 years, the detection of infectious disease agents has begun to include the use of nucleic acid-based technologies. Diagnosis of infection caused by parasitic organisms is the last field of clinical microbiology to incorporate these techniques and molecular techniques (e.g., PCR and hybridization assays) have recently been developed for the detection, species differentiation, and phylogenetic analysis of microsporidia. In this paper we review human microsporidial infections and describe and discuss these newly developed molecular techniques. PMID:10194459

  9. Advancing IM-CW Lidar Modulation Techniques for ASCENDS CO2 Column Measurements from Space

    NASA Astrophysics Data System (ADS)

    Campbell, J. F.; Lin, B.; Nehrir, A. R.; Harrison, F. W.; Chen, S.; Obland, M. D.

    2013-12-01

    Global atmospheric carbon dioxide (CO2) measurements through the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) decadal survey recommended space mission are critical for improving our understanding of CO2 sources and sinks. IM-CW (Intensity Modulated Continuous Wave) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS science requirements. In previous laboratory and flight experiments we have successfully used linear swept frequency modulation to discriminate surface lidar returns from intermediate aerosol and cloud contamination. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate clouds, which is a requirement for the inversion of the CO2 column mixing ratio from the instrument optical depth measurements, has been demonstrated with the linear swept frequency modulation technique. We are concurrently investigating advanced techniques to help improve the auto-correlation properties of the transmitted waveform implemented through physical hardware to make cloud rejection more robust in special restricted scenarios. Several different modulation techniques are compared including orthogonal linear swept, orthogonal non-linear swept, time shifted PN, sine wave modulated PN, and sine wave pulsed PN. Different PN code techniques are presented that are appropriate for different types of lidar hardware, including our current ASCENDS IM-CW concept space hardware. These techniques have excellent auto-correlation properties without sidelobes while possessing a finite bandwidth (by way of a new cyclic digital filter), which will reduce bias error in the presence of multiple scatterers. Our analyses show that the studied modulation techniques can increase the accuracy of CO2 column measurements from space.

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

    E-print Network

    Kilgour, Michael

    2015-01-01

    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-B\\"uttiker's probe technique" can properly replicate different transport mechanisms: phase coherent nonresonant tunneling, ballistic behavior, and hopping conduction, to provide results consistent with experiments. 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. Under large dephasing the electrical conductance is suppressed. (iii) At high enough temperatures, $k_BT/\\epsilon_B>1/25$, with $\\epsilon_B$ as ...

  11. 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.

  12. 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

  13. Advanced fluorescence microscopy techniques--FRAP, FLIP, FLAP, FRET and FLIM.

    PubMed

    Ishikawa-Ankerhold, Hellen C; Ankerhold, Richard; Drummen, Gregor P C

    2012-01-01

    Fluorescence microscopy provides an efficient and unique approach to study fixed and living cells because of its versatility, specificity, and high sensitivity. Fluorescence microscopes can both detect the fluorescence emitted from labeled molecules in biological samples as images or photometric data from which intensities and emission spectra can be deduced. By exploiting the characteristics of fluorescence, various techniques have been developed that enable the visualization and analysis of complex dynamic events in cells, organelles, and sub-organelle components within the biological specimen. The techniques described here are fluorescence recovery after photobleaching (FRAP), the related fluorescence loss in photobleaching (FLIP), fluorescence localization after photobleaching (FLAP), Förster or fluorescence resonance energy transfer (FRET) and the different ways how to measure FRET, such as acceptor bleaching, sensitized emission, polarization anisotropy, and fluorescence lifetime imaging microscopy (FLIM). First, a brief introduction into the mechanisms underlying fluorescence as a physical phenomenon and fluorescence, confocal, and multiphoton microscopy is given. Subsequently, these advanced microscopy techniques are introduced in more detail, with a description of how these techniques are performed, what needs to be considered, and what practical advantages they can bring to cell biological research. PMID:22469598

  14. 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.

  15. Monitoring of microbial souring in chemically treated, produced-water biofilm systems using molecular techniques.

    PubMed

    Kjellerup, B V; Veeh, R H; Sumithraratne, P; Thomsen, T R; Buckingham-Meyer, K; Frølund, B; Sturman, P

    2005-04-01

    The identification of bacteria in oil production facilities has previously been based on culture techniques. However, cultivation of bacteria from these often-extreme environments can lead to errors in identifying the microbial community members. In this study, molecular techniques including fluorescence in situ hybridization, PCR, denaturing gradient gel electrophoresis, and sequencing were used to track changes in bacterial biofilm populations treated with nitrate, nitrite, or nitrate+molybdate as agents for the control of sulfide production. Results indicated that nitrite and nitrate+molybdate reduced sulfide production, while nitrate alone had no effect on sulfide generation. No long-term effect on sulfide production was observed. Initial sulfate-reducing bacterial numbers were not influenced by the chemical treatments, although a significant increase in sulfate-reducing bacteria was observed after termination of the treatments. Molecular analysis showed a diverse bacterial population, but no major shifts in the population due to treatment effects were observed. PMID:15843975

  16. System Design Techniques for Reducing the Power Requirements of Advanced life Support Systems

    NASA Technical Reports Server (NTRS)

    Finn, Cory; Levri, Julie; Pawlowski, Chris; Crawford, Sekou; Luna, Bernadette (Technical Monitor)

    2000-01-01

    The high power requirement associated with overall operation of regenerative life support systems is a critical Z:p technological challenge. Optimization of individual processors alone will not be sufficient to produce an optimized system. System studies must be used in order to improve the overall efficiency of life support systems. Current research efforts at NASA Ames Research Center are aimed at developing approaches for reducing system power and energy usage in advanced life support systems. System energy integration and energy reuse techniques are being applied to advanced life support, in addition to advanced control methods for efficient distribution of power and thermal resources. An overview of current results of this work will be presented. The development of integrated system designs that reuse waste heat from sources such as crop lighting and solid waste processing systems will reduce overall power and cooling requirements. Using an energy integration technique known as Pinch analysis, system heat exchange designs are being developed that match hot and cold streams according to specific design principles. For various designs, the potential savings for power, heating and cooling are being identified and quantified. The use of state-of-the-art control methods for distribution of resources, such as system cooling water or electrical power, will also reduce overall power and cooling requirements. Control algorithms are being developed which dynamically adjust the use of system resources by the various subsystems and components in order to achieve an overall goal, such as smoothing of power usage and/or heat rejection profiles, while maintaining adequate reserves of food, water, oxygen, and other consumables, and preventing excessive build-up of waste materials. Reductions in the peak loading of the power and thermal systems will lead to lower overall requirements. Computer simulation models are being used to test various control system designs.

  17. 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

  18. 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 [Jacobs University Bremen, School of Science and Engineering Campus Ring 1, 28759 Bremen (Germany)

    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.

  19. SPECT and PET serve as molecular imaging techniques and in vivo biomarkers for brain metastases.

    PubMed

    Palumbo, Barbara; Buresta, Tommaso; Nuvoli, Susanna; Spanu, Angela; Schillaci, Orazio; Fravolini, Mario Luca; Palumbo, Isabella

    2014-01-01

    Nuclear medicine techniques (single photon emission computerized tomography, SPECT, and positron emission tomography, PET) represent molecular imaging tools, able to provide in vivo biomarkers of different diseases. To investigate brain tumours and metastases many different radiopharmaceuticals imaged by SPECT and PET can be used. In this review the main and most promising radiopharmaceuticals available to detect brain metastases are reported. Furthermore the diagnostic contribution of the combination of SPECT and PET data with radiological findings (magnetic resonance imaging, MRI) is discussed. PMID:24897023

  20. SPECT and PET Serve as Molecular Imaging Techniques and in Vivo Biomarkers for Brain Metastases

    PubMed Central

    Palumbo, Barbara; Buresta, Tommaso; Nuvoli, Susanna; Spanu, Angela; Schillaci, Orazio; Fravolini, Mario Luca; Palumbo, Isabella

    2014-01-01

    Nuclear medicine techniques (single photon emission computerized tomography, SPECT, and positron emission tomography, PET) represent molecular imaging tools, able to provide in vivo biomarkers of different diseases. To investigate brain tumours and metastases many different radiopharmaceuticals imaged by SPECT and PET can be used. In this review the main and most promising radiopharmaceuticals available to detect brain metastases are reported. Furthermore the diagnostic contribution of the combination of SPECT and PET data with radiological findings (magnetic resonance imaging, MRI) is discussed. PMID:24897023

  1. Ancillary techniques in bone marrow pathology: molecular diagnostics on bone marrow trephine biopsies

    Microsoft Academic Search

    Falko Fend; Oliver Bock; Markus Kremer; Katja Specht; Leticia Quintanilla-Martinez

    2005-01-01

    Pathologic examination of trephine bone marrow (BM) biopsies plays a central role in the diagnosis and staging of haematological\\u000a neoplasms and other disorders affecting haematopoiesis. Haematopathology has been profoundly influenced by the advent of molecular\\u000a genetic techniques suitable for paraffin-embedded tissues, and certain applications, such as the determination of B- and T-cell\\u000a clonality, belong to its standard diagnostic repertoire. Many

  2. Application of Molecular Fingerprinting Techniques to Explore the Diversity of Bacterial Endophytic Communities

    Microsoft Academic Search

    Leo S. van Overbeek; Jim van Vuurde; Jan D. van Elsas

    Molecular fingerprinting methods are required as tools to supplement conventional methods in endophyte research to study cultivable\\u000a and non-cultivable populations in plants. The intricacies of plants make these techniques difficult to perform. The presence\\u000a of chloroplast and mitochondrial DNA in total plant DNA extracts, the abundance of plant DNA versus bacterial DNA, and the\\u000a presence of (poly) phenolics may hamper

  3. NEU806 2011 Syllabus for the "molecular approach section" The goal of these sections is to introduce some very basic molecular tools/techniques,

    E-print Network

    Liu, Taosheng

    is to introduce some very basic molecular tools/techniques, which are routine procedures used in molecular neuroscience labs. Students will have the opportunity to practice genotyping, PCR, cloning, plasmid cloning strategies (by Hongbing Wang). 2. Student will clone the PCR products (obtained from Nov 23

  4. 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

  5. Process window enhancement using advanced RET techniques for 20nm contact layer

    NASA Astrophysics Data System (ADS)

    Ping, Yang; McGowan, Sarah; Gong, Ying; Foong, Yee Mei; Liu, Jian; Qiu, Jianhong; Shu, Vincent; Yan, Bo; Ye, Jun; Li, Pengcheng; Zhou, Hui; Pandey, Taksh; Liang, Jiao; Aquino, Chris; Baron, Stanislas; Kapasi, Sanjay

    2014-03-01

    At the 20nm technology node, it is challenging for simple resolution enhancements techniques (RET) to achieve sufficient process margin due to significant coupling effects for dense features. Advanced computational lithography techniques including Source Mask Optimization (SMO), thick mask modeling (M3D), Model Based Sub Resolution Assist Features (MB-SRAF) and Process Window Solver (PW Solver) methods are now required in the mask correction processes to achieve optimal lithographic goals. An OPC solution must not only converge to a nominal condition with high fidelity, but also provide this fidelity over an acceptable process window condition. The solution must also be sufficiently robust to account for potential scanner or OPC model tuning. In many cases, it is observed that with even a small change in OPC parameters, the mask correction could have a big change, therefore making OPC optimization quite challenging. On top of this, different patterns may have significantly different optimum source maps and different optimum OPC solution paths. Consequently, the need for finding a globally optimal OPC solution becomes important. In this work, we introduce a holistic solution including source and mask optimization (SMO), MB-SRAF, conventional OPC and Co-Optimization OPC, in which each technique plays a unique role in process window enhancement: SMO optimizes the source to find the best source solution for all critical patterns; Co-Optimization provides the optimized location and size of scattering bars and guides the optimized OPC solution; MB-SRAF and MB-OPC then utilizes all information from advanced solvers and performs a globally optimized production solution.

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

    E-print Network

    Dunin-Borkowski, Rafal E.

    Workshop on Magnetotactic Bacteria 9-11 June 2008, Balatonfüred, Hungary Advanced electron microscopy techniques for studying magnetosomes in magnetotactic bacteria Rafal E. Dunin-Borkowski1 , Takeshi) in air-dried cells of magnetotactic bacteria. These techniques have provided a wealth of information

  7. 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

  8. Complex Reaction Environments and Competing Reaction Mechanisms in Zeolite Catalysis: Insights from Advanced Molecular Dynamics.

    PubMed

    De Wispelaere, Kristof; Ensing, Bernd; Ghysels, An; Meijer, Evert Jan; Van Speybroeck, Veronique

    2015-06-22

    The methanol-to-olefin process is a showcase example of complex zeolite-catalyzed chemistry. At real operating conditions, many factors affect the reactivity, such as framework flexibility, adsorption of various guest molecules, and competitive reaction pathways. In this study, the strength of first principle molecular dynamics techniques to capture this complexity is shown by means of two case studies. Firstly, the adsorption behavior of methanol and water in H-SAPO-34 at 350?°C is investigated. Hereby an important degree of framework flexibility and proton mobility was observed. Secondly, the methylation of benzene by methanol through a competitive direct and stepwise pathway in the AFI topology was studied. Both case studies clearly show that a first-principle molecular dynamics approach enables unprecedented insights into zeolite-catalyzed reactions at the nanometer scale to be obtained. PMID:25951509

  9. New advanced surface modification technique: titanium oxide ceramic surface implants: long-term clinical results

    NASA Astrophysics Data System (ADS)

    Szabo, Gyorgy; Kovacs, Lajos; Barabas, Jozsef; Nemeth, Zsolt; Maironna, Carlo

    2001-11-01

    The purpose of this paper is to discuss the background to advanced surface modification technologies and to present a new technique, involving the formation of a titanium oxide ceramic coating, with relatively long-term results of its clinical utilization. Three general techniques are used to modify surfaces: the addition or removal of material and the change of material already present. Surface properties can also be changed without the addition or removal of material, through the laser or electron beam thermal treatment. The new technique outlined in this paper relates to the production of a corrosion-resistant 2000-2500 A thick, ceramic oxide layer with a coherent crystalline structure on the surface of titanium implants. The layer is grown electrochemically from the bulk of the metal and is modified by heat treatment. Such oxide ceramic-coated implants have a number of advantageous properties relative to implants covered with various other coatings: a higher external hardness, a greater force of adherence between the titanium and the oxide ceramic coating, a virtually perfect insulation between the organism and the metal (no possibility of metal allergy), etc. The coated implants were subjected to various physical, chemical, electronmicroscopic, etc. tests for a qualitative characterization. Finally, these implants (plates, screws for maxillofacial osteosynthesis and dental root implants) were applied in surgical practice for a period of 10 years. Tests and the experience acquired demonstrated the good properties of the titanium oxide ceramic-coated implants.

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

    SciTech Connect

    Lebedev, G. V., E-mail: lgv2004@mail.ru; Petrov, V. V. [National Research Center Kurchatov Institute (Russian Federation); Bobylyov, V. T.; Butov, R. I.; Zhukov, A. M.; Sladkov, A. A. [Dukhov VNIIA (Russian Federation)

    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.

  11. Probing the molecular interaction of triazole fungicides with human serum albumin by multispectroscopic techniques and molecular modeling.

    PubMed

    Zhang, Jing; Zhuang, Shulin; Tong, Changlun; Liu, Weiping

    2013-07-31

    Triazole fungicides, one category of broad-spectrum fungicides, are widely applied in agriculture and medicine. The extensive use leads to many residues and casts potential detrimental effects on aquatic ecosystems and human health. After exposure of the human body, triazole fungicides may penetrate into the bloodstream and interact with plasma proteins. Whether they could have an impact on the structure and function of proteins is still poorly understood. By using multispectroscopic techniques and molecular modeling, the interaction of several typical triazole fungicides with human serum albumin (HSA), the major plasma protein, was investigated. The steady-state and time-resolved fluorescence spectra manifested that static type, due to complex formation, was the dominant mechanism for fluorescence quenching. Structurally related binding modes speculated by thermodynamic parameters agreed with the prediction of molecular modeling. For triadimefon, hydrogen bonding with Arg-218 and Arg-222 played an important role, whereas for imazalil, myclobutanil, and penconazole, the binding process was mainly contributed by hydrophobic and electrostatic interactions. Via alterations in three-dimensional fluorescence and circular dichroism spectral properties, it was concluded that triazoles could induce slight conformational and some microenvironmental changes of HSA. It is anticipated that these data can provide some information for possible toxicity risk of triazole fungicides to human health and be helpful in reinforcing the supervision of food safety. PMID:23834846

  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. Recent Advances in the Molecular Pathogenesis of Dystonia-Plus Syndromes and Heredodegenerative Dystonias

    PubMed Central

    Casper, Catharina; Kalliolia, Eirini; Warner, Thomas T

    2013-01-01

    The majority of studies investigating the molecular pathogenesis and cell biology underlying dystonia have been performed in individuals with primary dystonia. This includes monogenic forms such as DYT1and DYT6 dystonia, and primary focal dystonia which is likely to be multifactorial in origin. In recent years there has been renewed interest in non-primary forms of dystonia including the dystonia-plus syndromes and heredodegenerative disorders. These are caused by a variety of genetic mutations and their study has contributed to our understanding of the neuronal dysfunction that leads to dystonia These findings have reinforced themes identified from study of primary dystonia including abnormal dopaminergic signalling, cellular trafficking and mitochondrial function. In this review we highlight recent advances in the understanding of the dystonia-plus syndromes and heredodegenerative dystonias. PMID:23814535

  14. Control of molecular weight of polystyrene using the reverse iodine transfer polymerization (RITP)-emulsion technique.

    PubMed

    Oh, Hyeong Geun; Shin, Hongcheol; Jung, Hyejun; Lee, Byung Hyung; Choe, Soonja

    2011-01-15

    The RITP-emulsion polymerization of styrene in the presence of molecular iodine has been successfully performed using potassium persulfate (KPS) as an initiator and 1-hexadecanesulfonate as an emulsifier under argon atmosphere at 80°C for 7 hrs in the absence of light. The effects of the iodine concentration, molar ratio between KPS and iodine, and solid contents on the molecular weight of polystyrene (PS) were studied. As the iodine concentration increased from 0.05 to 0.504 mmol under the fixed [KPS]/[I(2)] ratio at 4.5, the weight-average molecular weight of PS substantially decreased from 126,120 to 35,690 g/mol, the conversion increased from 85.0% to 95.2%, and the weight-average particle diameter decreased from 159 to 103 nm. In addition, as the ratio of [KPS]/[I(2)] increased from 0.5 to 6.0 at the fixed [I(2)] of 0.504 mmol, the weight-average molecular weight of PS decreased from 72,170 to 30,640 g/mol with high conversion between 81.7% and 96.5%. Moreover, when the styrene solid content increased from 10 to 40 wt.% at the fixed [KPS]/[I(2)] ratio of 4.5, the weight-average molecular weight of PS varied between 33,500 and 37,200 g/mol, the conversion varied between 94.9% and 89.7% and the weight-average diameter varied from 122 to 205 nm. Thus, the control of molecular weight of PS less than 100,000g/mol with high conversion (95%) and particle stability of up to 40 wt.% solid content were easily achieved through the usage of iodine with suitable ratio of [KPS]/[I(2)] in the RITP-emulsion polymerization technique, which is of great industrial importance. PMID:20950818

  15. Resected gastric cancer with D2 dissection: advances in adjuvant chemoradiotherapy and radiotherapy techniques.

    PubMed

    Wu, Qiang; Li, Guangjun; Xu, Feng

    2015-06-01

    Surgery is the main treatment option for locally advanced gastric cancer. D2 dissection has been recommended worldwide as standard lymphadenectomy for resectable gastric cancer. Furthermore, the role of peri- or postoperative chemotherapy for D2-dissected gastric cancer has been established in both Western and European countries. It has been disputed whether adding radiotherapy to chemotherapy could further benefit those patients. Until recently, studies from Korea and China may have made it clear. In North America, however, the INT-0116 trial does not rule out that chemoradiotherapy is effective in patients with D2 dissection, but the ongoing CRITICS trial will, hopefully, clarify this. In addition, literature published in the past decade supports the theory that improved radiotherapy techniques are likely to accurately deliver radiation dose and significantly reduce radiation toxicity. Finally, the status of E2F-1 and HER-2 may be associated with efficacy of radiotherapy based on retrospective studies. PMID:26004039

  16. STAR-LITE (Safe Techniques Advance Research - Laboratory Interactive Training Environment)

    NSDL National Science Digital Library

    Janus Research Group

    The National Institutes of Health, Division of Occupational Health and Safety (DOHS) developed a laboratory safety training program called STAR-LITE (Safe Techniques Advance Research – Laboratory Interactive Training Environment.) STAR-LITE is an interactive computer-based laboratory safety training program for high school students and undergraduate university students. The program incorporates common features seen in today’s video games, i.e., selection of an individualized character; first-person views; and three-dimensional graphics. The method of instruction integrates visualization of consequences, e.g., slips/trips/falls, inhalation of chemical hazards, spills of biohazardous liquids, development of critical-thinking proficiencies, and application of problem-solving skills.

  17. 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.

  18. Efficient Boolean and multi-input flow techniques for advanced mask data processing

    NASA Astrophysics Data System (ADS)

    Salazar, Daniel; Moore, Bill; Valadez, John

    2012-11-01

    Mask data preparation (MDP) typically involves multiple flows, sometimes consisting of many steps to ensure that the data is properly written on the mask. This may include multiple inputs, transformations (scaling, orientation, etc.), and processing (layer extraction, sizing, Boolean operations, data filtering). Many MDP techniques currently in practice require multiple passes through the input data and/or multiple file I/O steps to achieve these goals. This paper details an approach which efficiently process the data, resulting in minimal I/O and greatly improved turnaround times (TAT). This approach takes advanced processing algorithms and adapts them to produce efficient and reliable data flow. In tandem with this processing flow, an internal jobdeck mapping approach, transparent to the user, allows an essentially unlimited number of pattern inputs to be handled in a single pass, resulting in increased flexibility and ease of use. Transformations and processing operations are critical to MDP. Transformations such as scaling, reverse tone and orientation, along with processing including sizing, Boolean operations and data filtering are key parts of this. These techniques are often employed in sequence and/or in parallel in a complex functional chain. While transformations typically are done "up front" when the data is input, processing is less straightforward, involving multiple reads and writes to handle the more intricate functionality and also the collection of input patterns which may be required to produce the data that comprises a single mask. The approach detailed in this paper consists of two complementary techniques: efficient MDP flow and jobdeck mapping. Efficient MDP flow is achieved by pipelining the output of each step to the input of the subsequent step. Rather than writing the output of a particular processing step to file and then reading it in to the following step, the pipelining or chaining of the steps results in an efficient flow with minimal file I/O. The efficient MDP flow is enhanced by a technique called jobdeck mapping which allows in essence an unlimited number of pattern inputs by taking each transformed pattern and including it in an input jobdeck. Making use of established jobdeck handling capabilities, the user-selected input pattern/transformation combinations are mapped to an input jobdeck which is processed by the advanced flow, allowing great flexibility and user control of the process.

  19. Intelligent systems for the characterization and quantification of microbial systems from advanced analytical techniques

    NASA Astrophysics Data System (ADS)

    Goodacre, Royston; McGovern, Aoife C.; Timmins, Eadaoin M.; Winson, Michael K.; Kaderbhai, Naheed; Broadhurst, David; Taylor, Janet; Gilbert, Richard; Rowland, Jem J.; Kell, Douglas B.

    1999-12-01

    The ideal method for rapid, precise and accurate analyses of the chemical composition of microbial systems, both within biotechnology and for the identification of potentially pathogenic organisms, would have minimum sample preparation, would analyze samples directly, would be rapid, automated, accurate and (at least relatively) inexpensive. With recent developments in analytical instrumentation, these requirements are increasingly being fulfilled by the vibrational spectroscopic methods of Fourier transform-infrared spectroscopy (FT-IR) and dispersive Raman microscopy. Both techniques are extremely rapid, taking seconds rather than minutes to collect a spectrum from a sample and are fully automated. This paper gives an overview of some of the biotechnological and clinical studies that are currently in progress in 'The Aberystwyth Quantitative Biology' and 'Molecular and Spectroscopic Systematics' groups within the Institute of Biological Sciences, University of Wales, Aberystwyth.

  20. 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

  1. Using DRIFT molecular spectroscopy with uni- and multivariate spectral techniques to detect protein molecular structure differences among different genotypes of barley.

    PubMed

    Liu, Na; Yu, Peiqiang

    2010-05-26

    The objectives of this study were to characterize protein molecular structure using DRIFT spectroscopy with univariate and multivariate molecular spectral analyses and identify the structure differences in both hull and seeds among six spring barley varieties [AC Metcalfe (malting-type), CDC Dolly (feed-type, spring forage type), McLeod (feed-type), CDC Helgason (feed-type), CDC Trey (feed-type), CDC Cowboy (feed-type)]. The molecular structure spectral analyses involved protein amide I and II region ca. 1716-1485 cm(-1) (attributed to protein amide I C=O and C-N stretching; amide II N-H bending and C-N stretching) together with agglomerative hierarchical cluster (CLA) and principal component analyses (PCA). The results showed that the molecular spectral techniques were able to identify spectral differences associated with the molecular structural differences among the barley varieties. The molecular spectral analyses at the region of ca. 1715-1485 cm(-1) together with the cluster and principal component analyses were able to show that the molecular structures of the seeds (NOT hull) exhibited distinguished differences among the barley varieties. It was found that CDC Helgason had the distinguished differences from AC Metcalfe, McLeod, and CDC Cowboy in both protein amide I and II. The molecular spectral technique provides a new approach for plant protein molecular structure and biopolymer conformation study. PMID:20441231

  2. Molecular and genetic advances in the regeneration of the intervertebral disc

    PubMed Central

    Maerz, Tristan; Herkowitz, Harry; Baker, Kevin

    2013-01-01

    Background: Owing to the debilitating nature of degenerative disc disease (DDD) and other spine pathologies, significant research has been performed with the goal of healing or regenerating the intervertebral disc (IVD). Structural complexity, coupled with low vascularity and cellularity, make IVD regeneration an extremely challenging task. Methods: Tissue engineering-based strategies utilize three components to enhance tissue regeneration; scaffold materials to guide cell growth, biomolecules to enhance cell migration and differentiation, and cells (autologous, or allogeneic) to initiate the process of tissue formation. Significant advances in IVD regeneration have been made utilizing these tissue engineering strategies. Results: The current literature demonstrates that members of the transforming growth factor beta (TGF-?) superfamily are efficacious in the regeneration of an anabolic response in the IVD and to facilitate chondrogenic differentiation. Gene therapy, though thwarted by safety concerns and the risk of ectopic transfection, has significant potential for a targeted and sustained regenerative response. Stem cells in combination with injectable, biocompatible, and biodegradable scaffolds in the form of hydrogels can differentiate into de novo IVD tissue and facilitate regeneration of the existing matrix. Therapies that address both anabolism and the inherent catabolic state of the IVD using either direct inhibitors or broad-spectrum inhibitors show extensive promise. Conclusion: This review article summarizes the genetic and molecular advances that promise to play an integral role in the development of new strategies to combat DDD and promote healing of injured discs. PMID:23646279

  3. 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.

  4. 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.

  5. 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.

  6. A technique for mass spectrometer measurements of atomic and molecular oxygen in the lower thermosphere

    NASA Technical Reports Server (NTRS)

    Kayser, D. C.; Potter, W. E.

    1978-01-01

    A neutral mass spectrometer with a quasi-open ion source was flown on each of the Atmosphere Explorer (AE) C, D, and E satellites. The three instruments provided an opportunity to study the effects of different source insert materials on the source surface chemistry. It was found that, after a period of conditioning in space, the recombination coefficient of atomic oxygen on gold appears to be substantially lower than it is on Nichrome V. The lower recombination coefficient on gold allows the spectrometer to directly measure a significant fraction of the incident atomic oxygen, making it possible to distinguish between ambient O and O2. Equations are developed to calculate the atomic and molecular oxygen densities. Preliminary measurements of molecular oxygen densities obtained by this technique agree well with measurements taken in the fly-through mode of operation.

  7. A new crossed molecular beam apparatus using time-sliced ion velocity imaging technique

    SciTech Connect

    Wu Guorong; Zhang Weiqing; Pan Huilin; Shuai Quan; Jiang Bo; Dai Dongxu; Yang Xueming [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023 (China)

    2008-09-15

    A new crossed molecular beam apparatus has been constructed for investigating polyatomic chemical reactions using the time-sliced ion velocity map imaging technique. A unique design is adopted for one of the two beam sources and allows us to set up the molecular beam source either horizontally or vertically. This can be conveniently used to produce versatile atomic or radical beams from photodissociation and as well as electric discharge. Intensive H-atom beam source with high speed ratio was produced by photodissociation of the HI molecule and was reacted with the CD{sub 4} molecule. Vibrational-state resolved HD product distribution was measured by detecting the CD{sub 3} product. Preliminary results were also reported on the F+SiH{sub 4} reaction using the discharged F atom beam. These results demonstrate that this new instrument is a powerful tool for investigating chemical dynamics of polyatomic reactions.

  8. Penicillium marneffei Infection and Recent Advances in the Epidemiology and Molecular Biology Aspects

    PubMed Central

    Vanittanakom, Nongnuch; Cooper, Chester R.; Fisher, Matthew C.; Sirisanthana, Thira

    2006-01-01

    Penicillium marneffei infection is an important emerging public health problem, especially among patients infected with human immunodeficiency virus in the areas of endemicity in southeast Asia, India, and China. Within these regions, P. marneffei infection is regarded as an AIDS-defining illness, and the severity of the disease depends on the immunological status of the infected individual. Early diagnosis by serologic and molecular assay-based methods have been developed and are proving to be important in diagnosing infection. The occurrence of natural reservoirs and the molecular epidemiology of P. marneffei have been studied; however, the natural history and mode of transmission of the organism remain unclear. Soil exposure, especially during the rainy season, has been suggested to be a critical risk factor. Using a highly discriminatory molecular technique, multilocus microsatellite typing, to characterize this fungus, several isolates from bamboo rats and humans were shown to share identical multilocus genotypes. These data suggest either that transmission of P. marneffei may occur from rodents to humans or that rodents and humans are coinfected from common environmental sources. These putative natural cycles of P. marneffei infection need further investigation. Studies on the fungal genetics of P. marneffei have been focused on the characterization of genetic determinants that may play important roles in asexual development, mycelial-to-yeast phase transition, and the expression of antigenic determinants. Molecular studies have identified several genes involved in germination, hyphal development, conidiogenesis, and yeast cell polarity. A number of functionally important genes, such as the malate synthase- and catalase-peroxidase protein-encoding genes, have been identified as being upregulated in the yeast phase. Future investigations pertaining to the roles of these genes in host-fungus interactions may provide the key knowledge to understanding the pathogenicity of P. marneffei. PMID:16418525

  9. Planetary and Space Science 55 (2007) 19591963 A technique to determine the mean molecular mass of a planetary

    E-print Network

    Mendillo, Michael

    2007-01-01

    Planetary and Space Science 55 (2007) 1959­1963 A technique to determine the mean molecular mass, Boston, MA 02215, USA b Planetary and Space Sciences Research Institute, The Open University, Walton Hall

  10. Comments on advanced, time-resolved imaging techniques for free-electron laser (FEL) experiments

    SciTech Connect

    Lumpkin, A.H.

    1992-01-01

    An extensive set of time-resolved imaging experiments has been performed on rf-linac driven free-electron lasers (FELs) over the past few years. These experiments have addressed both micropulse and macropulse timescales on both the charged-particle beam and the wiggler/undulator outputs (spontaneous emission and lasing). A brief review of first measurements on photoinjecter micropulse elongation, submacropulse phase slew in drive lasers, submacropulse wavelength shifts in lasers, etc. is presented. This is followed by discussions of new measurements of 35-MeV electron beam micropulse bunch length (<10 ps) using optical transition radiation, some of the first single bend synchrotron radiation beam profile measurements at gamma <80, and comments on the low-jitter synchroscan streak camera tuner. These techniques will be further developed on the 200-650 MeV linac test stand at the Advanced Photon Source (APS) in the next few years. Such techniques should be adaptable to many of the present FEL designs and to some aspects of the next generation of light sources.

  11. Comments on advanced, time-resolved imaging techniques for free-electron laser (FEL) experiments

    SciTech Connect

    Lumpkin, A.H.

    1992-11-01

    An extensive set of time-resolved imaging experiments has been performed on rf-linac driven free-electron lasers (FELs) over the past few years. These experiments have addressed both micropulse and macropulse timescales on both the charged-particle beam and the wiggler/undulator outputs (spontaneous emission and lasing). A brief review of first measurements on photoinjecter micropulse elongation, submacropulse phase slew in drive lasers, submacropulse wavelength shifts in lasers, etc. is presented. This is followed by discussions of new measurements of 35-MeV electron beam micropulse bunch length (<10 ps) using optical transition radiation, some of the first single bend synchrotron radiation beam profile measurements at gamma <80, and comments on the low-jitter synchroscan streak camera tuner. These techniques will be further developed on the 200-650 MeV linac test stand at the Advanced Photon Source (APS) in the next few years. Such techniques should be adaptable to many of the present FEL designs and to some aspects of the next generation of light sources.

  12. Recoil separators for radiative capture using radioactive ion beams. Recent advances and detection techniques

    NASA Astrophysics Data System (ADS)

    Ruiz, Chris; Greife, Uwe; Hager, Ulrike

    2014-06-01

    Radiative capture reactions involving the fusion of hydrogen or helium are ubiquitous in the stellar history of the universe, and are some of the most important reactions in the processes that govern nucleosynthesis and energy generation in both static and explosive scenarios. However, radiative capture reactions pose some of the most difficult experimental challenges due to extremely small cross sections. With the advent of recoil separators and techniques in inverse kinematics, it is now possible to measure radiative capture reactions on very short-lived radioactive nuclei, and in the presence of high experimental backgrounds. In this paper we review the experimental needs for making measurements of astrophysical importance on radiative capture reactions. We also review some of the important historical advances in the field of recoil separators as well as describe current techniques and performance milestones, including descriptions of some of the separators most recently working at radioactive ion beam facilities, such as DRAGON at TRIUMF and the DRS at the Holifield Radioactive Ion Beam Facility. We will also summarize some of the scientific highlight measurements at the RIB facilities.

  13. Advanced system identification techniques for wind turbine structures with special emphasis on modal parameters

    SciTech Connect

    Bialasiewicz, J.T.

    1995-06-01

    The goal of this research is to develop advanced system identification techniques that can be used to accurately measure the frequency response functions of a wind-turbine structure immersed in wind noise. To allow for accurate identification, the authors have developed a special test signal called the Pseudo-Random Binary Sequence (PRBS). The Matlab program that generates this signal allows the user to interactively tailor its parameters for the frequency range of interest based on the response of the wind turbine under test. By controlling NREL`s Mobile Hydraulic Shaker System, which is attached to the wind turbine structure, the PRBS signal produces the wide-band excitation necessary to perform system identification in the presence of wind noise. The techniques presented here will enable researchers to obtain modal parameters from an operating wind turbine, including frequencies, damping coefficients, and mode shapes. More importantly, the algorithms they have developed and tested (so far using input-output data from a simulated structure) permit state-space representation of the system under test, particularly the modal state space representation. This is the only system description that reveals the internal behavior the system, such as the interaction between the physical parameters, and which, in contrast to transfer functions, is valid for non-zero initial conditions.

  14. 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.

  15. EPS in Environmental Microbial Biofilms as Examined by Advanced Imaging Techniques

    NASA Astrophysics Data System (ADS)

    Neu, T. R.; Lawrence, J. R.

    2006-12-01

    Biofilm communities are highly structured associations of cellular and polymeric components which are involved in biogenic and geogenic environmental processes. Furthermore, biofilms are also important in medical (infection), industrial (biofouling) and technological (biofilm engineering) processes. The interfacial microbial communities in a specific habitat are highly dynamic and change according to the environmental parameters affecting not only the cellular but also the polymeric constituents of the system. Through their EPS biofilms interact with dissolved, colloidal and particulate compounds from the bulk water phase. For a long time the focus in biofilm research was on the cellular constituents in biofilms and the polymer matrix in biofilms has been rather neglected. The polymer matrix is produced not only by different bacteria and archaea but also by eukaryotic micro-organisms such as algae and fungi. The mostly unidentified mixture of EPS compounds is responsible for many biofilm properties and is involved in biofilm functionality. The chemistry of the EPS matrix represents a mixture of polymers including polysaccharides, proteins, nucleic acids, neutral polymers, charged polymers, amphiphilic polymers and refractory microbial polymers. The analysis of the EPS may be done destructively by means of extraction and subsequent chemical analysis or in situ by means of specific probes in combination with advanced imaging. In the last 15 years laser scanning microscopy (LSM) has been established as an indispensable technique for studying microbial communities. LSM with 1-photon and 2-photon excitation in combination with fluorescence techniques allows 3-dimensional investigation of fully hydrated, living biofilm systems. This approach is able to reveal data on biofilm structural features as well as biofilm processes and interactions. The fluorescent probes available allow the quantitative assessment of cellular as well as polymer distribution. For this purpose lectin-binding- analysis has been suggested as a suitable approach to image glycoconjugates within the polymer matrix of biofilm communities. More recently synchrotron radiation is increasingly recognized as a powerful tool for studying biological samples. Hard X-ray excitation can be used to map elemental composition whereas IR imaging allows examination of biological macromolecules. A further technique called soft X-ray scanning transmission microscopy (STXM) has the advantage of both techniques and may be employed to detect elements as well as biomolecules. Using the appropriate spectra, near edge X-ray absorption fine structure (NEXAFS) microscopy allows quantitative chemical mapping at 50 nm resolution. In this presentation the applicability of LSM and STXM will be demonstrated using several examples of different environmental biofilm systems. The techniques in combination provide a new view of complex microbial communities and their interaction with the environment. These advanced imaging techniques offer the possibility to study the spatial structure of cellular and polymeric compounds in biofilms as well as biofilm microhabitats, biofilm functionality and biofilm processes.

  16. 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.

  17. 78 FR 68058 - Next Generation Risk Assessment: Incorporation of Recent Advances in Molecular, Computational...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-13

    ...Molecular, Computational, and Systems Biology [External Review Draft] AGENCY: Environmental...Molecular, Computational, and Systems Biology [External Review Draft]'' (EPA...molecular, computational, and systems biology data can better inform risk...

  18. 78 FR 59927 - Next Generation Risk Assessment: Incorporation of Recent Advances in Molecular, Computational...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-30

    ...Molecular, Computational, and Systems Biology [External Review Draft] AGENCY: Environmental...Molecular, Computational, and Systems Biology [External Review Draft]'' (EPA...Molecular, Computational, and Systems Biology [External Review Draft]'' is...

  19. Using FDTD to improve our understanding of partial wave spectroscopy for advancing ultra early-stage cancer detection techniques

    Microsoft Academic Search

    Jamesina J. Simpson; I. R. Capoglu; V. Backman

    2009-01-01

    We present numerical modeling techniques and results geared towards improving our understanding of the physical basis underlying partial wave spectroscopy. This work is in support of an ongoing effort in developing and advancing ultra early-stage cancer detection techniques. First, our initial finite-difference time-domain (FDTD) modeling methodology and results for synthesizing partial wave spectroscopy are presented for an inhomogeneous dielectric sphere.

  20. The ORIGAMI Project: advanced tools and techniques for high-end mixing and interaction between real and virtual content

    Microsoft Academic Search

    Giovanni Bazzoni; Enrico Bianchi; Oliver Grau; Alec Knox; Reinhard Koch; Fabio Lavagetto; Alex Parkinson; Federico Pedersini; Augusto Sarti; Graham Thomas; Stefano Tubaro

    2002-01-01

    ORIGAMI is an EU-funded IST project with the goal to develop advanced tools and new production techniques for high-quality mixing of real and virtual content for film and TV productions. In particular, the project proposes new techniques for 3D camera calibration and tracking and for 3D scene reconstruction and plenoptic modelling. Such solutions will support a variety of different object

  1. An Intensive Hands-on Course Designed to Teach Molecular Biology Techniques to Physiology Graduate Students

    NSDL National Science Digital Library

    Dr. Andrea D. Weston (University of Western Ontario Department of Physiology)

    2002-03-01

    To address a growing need to make research trainees in physiology comfortable with the tools of molecular biology, we have developed a laboratory-intensive course designed for graduate students. This course is offered to a small group of students over a three-week period and is organized such that comprehensive background lectures are coupled with extensive hands-on experience. The course is divided into seven modules, each organized by a faculty member who has particular expertise in the area covered by that module. The modules focus on basic methods such as cDNA subcloning, sequencing, gene transfer, polymerase chain reaction, and protein and RNA expression analysis. Each module begins with a lecture that introduces the technique in detail by providing a historical perspective, describing both the uses and limitations of that technique, and comparing the method with others that yield similar information. Most of the lectures are followed by a laboratory session during which students follow protocols that were carefully designed to avoid pitfalls. Throughout these laboratory sessions, students are given an appreciation of the importance of proper technique and accuracy. Communication among the students, faculty, and the assistant coordinator is focused on when and why each procedure would be used, the importance of each step in the procedure, and approaches to troubleshooting. The course ends with an exam that is designed to test the studentsÂ? general understanding of each module and their ability to apply the various techniques to physiological questions.

  2. Evaluation of genetically modified sugarcane lines carrying Cry 1AC gene using molecular marker techniques.

    PubMed

    Ismail, Roba M

    2013-01-01

    Five genetically modified insect resistant sugarcane lines harboring the Bt Cry 1AC gene to produce insecticidal proteins were compared with non-transgenic control by using three types of molecular marker techniques namely, RAPD, ISSR and AFLP. These techniques were applied on transgenic and non-transgenic plants to investigate the genetic variations, which may appear in sugarcane clones. This variation might demonstrate the genomic changes associated with the transformation process, which could change important molecular basis of various biological phenomena. Genetic variations were screened using 22 different RAPD primers, 10 ISSR primers and 13 AFLP primer combinations. Analysis of RAPD and ISSR banding patterns gave no exclusive evidence for genetic variations. Meanwhile, the percentage of polymorphic bands was 0.45% in each of RAPD and ISSR, while the polymorphism generated by AFLP analysis was 1.8%. The maximum percentage of polymorphic bands was 1.4%, 1.1% and 5.5% in RAPD, ISSR and AFLP, respectively. These results demonstrate that most transgenic lines showed genomic homogeneity and verified minor genomic changes. Dendrograms revealing the relationships among the transgenic and control plants were developed from the data of each of the three marker types. PMID:23549345

  3. 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....

  4. 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…

  5. Advances in turbulent mixing techniques to study microsecond protein folding reactions

    PubMed Central

    Kathuria, Sagar V.; Chan, Alexander; Graceffa, Rita; Nobrega, R. Paul; Matthews, C. Robert; Irving, Thomas C.; Perot, Blair; Bilsel, Osman

    2013-01-01

    Recent experimental and computational advances in the protein folding arena have shown that the readout of the one-dimensional sequence information into three-dimensional structure begins within the first few microseconds of folding. The initiation of refolding reactions has been achieved by several means, including temperature jumps, flash photolysis, pressure jumps and rapid mixing methods. One of the most commonly used means of initiating refolding of chemically-denatured proteins is by turbulent flow mixing with refolding dilution buffer, where greater than 99% mixing efficiency has been achieved within 10’s of microseconds. Successful interfacing of turbulent flow mixers with complementary detection methods, including time-resolved Fluorescence Spectroscopy (trFL), Förster Resonance Energy Transfer (FRET), Circular Dichroism (CD), Small-Angle X-ray Scattering (SAXS), Hydrogen Exchange (HX) followed by Mass Spectrometry (MS) and Nuclear Magnetic Resonance Spectroscopy (NMR), Infrared Spectroscopy (IR), and Fourier Transform IR Spectroscopy (FTIR), has made this technique very attractive for monitoring various aspects of structure formation during folding. Although continuous-flow (CF) mixing devices interfaced with trFL detection have a dead time of only 30 µs, burst-phases have been detected in this time scale during folding of peptides and of large proteins (e.g., CheY and TIM barrels). Furthermore, a major limitation of CF mixing technique has been the requirement of large quantities of sample. In this brief communication, we will discuss the recent flurry of activity in micromachining and microfluidics, guided by computational simulations, that are likely to lead to dramatic improvements in time resolution and sample consumption for CF mixers over the next few years. PMID:23868289

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

    SciTech Connect

    Yoon, Myonggeun, E-mail: radioyoon@gmail.com [Proton Therapy Center, National Cancer Center, Goyang (Korea, Republic of); Shin, Dong Ho [Proton Therapy Center, National Cancer Center, Goyang (Korea, Republic of); Kim, Jinsung [Department of Radiation Oncology, Samsung Medical Center, Seoul (Korea, Republic of); Kim, Jong Won; Kim, Dae Woong; Park, Sung Yong; Lee, Se Byeong; Kim, Joo Young [Proton Therapy Center, National Cancer Center, Goyang (Korea, Republic of); Park, Hyeon-Jin; Park, Byung Kiu [Pediatric Oncology Clinic, Center for Specific Organs Cancer, National Cancer Center, Goyang (Korea, Republic of); Shin, Sang Hoon [Neuro-Oncology Clinic, Center for Specific Organs Cancer, National Cancer Center, Goyang (Korea, Republic of)

    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.

  7. 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...

  8. Advanced Characterization Techniques for Defining Vineyard Management Zones Susan Hubbard*1,2, Yoram Rubin*1, and Phil Freese*3

    E-print Network

    Rubin, Yoram

    Advanced Characterization Techniques for Defining Vineyard Management Zones Susan Hubbard*1@lbl.gov II. SOIL WATER CONTENT ESTIMATION AT THE MONDAVI VINEYARD USING GPR GROUNDWAVE DATA Surface Ground and subsequently to estimate soil water content within vineyard sites in a non-invasive and manner and with high

  9. A review of techniques, advances and outstanding issues in numerical modelling for rock mechanics and rock engineering

    Microsoft Academic Search

    L. Jing

    2003-01-01

    The purpose of this review paper is to present the techniques, advances, problems and likely future developments in numerical modelling for rock mechanics. Such modelling is essential for studying the fundamental processes occurring in rocks and for rock engineering design. The review begins by explaining the special nature of rock masses and the consequential difficulties when attempting to model their

  10. Accepted in Journal of Nuclear Materials Advanced characterization techniques for SiC and PyC coatings on high-

    E-print Network

    Paris-Sud XI, Université de

    Accepted in Journal of Nuclear Materials Advanced characterization techniques for SiC and Py be first examined. The SiC layer is expected to have a cubic structure (-SiC) to compensate for the swelling effect due to irradiation. The SiC grain size is an important parameter to characterize because

  11. Development of urban area geospatial information products from high resolution satellite imagery using advanced image analysis techniques

    Microsoft Academic Search

    Aaron K. Shackelford

    2004-01-01

    The latest generation of commercial satellite imaging sensors have a number of characteristics (e.g. high spatial resolution, multispectral bands, and quick revisit time), that make them ideal data sources for a variety of urban area applications. The goal of this doctoral research was to develop advanced automated and semi-automated image analysis and classification techniques for the extraction of urban area

  12. The novel quantitative technique for assessment of gait symmetry using advanced statistical learning algorithm.

    PubMed

    Wu, Jianning; Wu, Bin

    2015-01-01

    The accurate identification of gait asymmetry is very beneficial to the assessment of at-risk gait in the clinical applications. This paper investigated the application of classification method based on statistical learning algorithm to quantify gait symmetry based on the assumption that the degree of intrinsic change in dynamical system of gait is associated with the different statistical distributions between gait variables from left-right side of lower limbs; that is, the discrimination of small difference of similarity between lower limbs is considered the reorganization of their different probability distribution. The kinetic gait data of 60 participants were recorded using a strain gauge force platform during normal walking. The classification method is designed based on advanced statistical learning algorithm such as support vector machine algorithm for binary classification and is adopted to quantitatively evaluate gait symmetry. The experiment results showed that the proposed method could capture more intrinsic dynamic information hidden in gait variables and recognize the right-left gait patterns with superior generalization performance. Moreover, our proposed techniques could identify the small significant difference between lower limbs when compared to the traditional symmetry index method for gait. The proposed algorithm would become an effective tool for early identification of the elderly gait asymmetry in the clinical diagnosis. PMID:25705672

  13. Advanced real-time dynamic scene generation techniques for improved performance and fidelity

    NASA Astrophysics Data System (ADS)

    Bowden, Mark H.; Buford, James A.; Mayhall, Anthony J.

    2000-07-01

    Recent advances in real-time synthetic scene generation for Hardware-in-the-loop (HWIL) testing at the U.S. Army Aviation and Missile Command (AMCOM) Aviation and Missile Research, Development, and Engineering Center (AMRDEC) improve both performance and fidelity. Modeling ground target scenarios requires tradeoffs because of limited texture memory for imagery and limited main memory for elevation data. High- resolution insets have been used in the past to provide better fidelity in specific areas, such as in the neighborhood of a target. Improvements for ground scenarios include smooth transitions for high-resolution insets to reduce high spatial frequency artifacts at the borders of the inset regions and dynamic terrain paging to support large area databases. Transport lag through the scene generation system, including sensor emulation and interface components, has been dealt with in the past through the use of sub-window extraction from oversize scenes. This compensates for spatial effects of transport lag but not temporal effects. A new system has been developed and used successfully to compensate for a flashing coded beacon in the scene. Other techniques have been developed to synchronize the scene generator with the seeker under test (SUT) and to model atmospheric effects, sensor optic and electronics, and angular emissivity attenuation.

  14. On advanced estimation techniques for exoplanet detection and characterization using ground-based coronagraphs

    NASA Astrophysics Data System (ADS)

    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

    2012-07-01

    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.

  15. Comparison of molecular and microscopic technique for detection of Theileria spp. in carrier cattle.

    PubMed

    Noaman, Vahid

    2014-03-01

    In Iran, theileriosis is normally diagnosed with traditional Giemsa staining method. This is not applicable for identification of the carrier animals. The aim of this study was to compare conventional Giemsa staining method with the PCR technique in the detection of Theileria organisms. In this study, examinations were performed on 150 blood samples from cattle without clinical signs. Sensitivity and specificity of 50 microscopic fields were compared with Theileria specific PCR. The degree of agreement between PCR and microscopic test was determined by Kappa (?) values with 95 % confidence intervals. PCR showed that 42 samples were Theileria spp. positive, while routine microscopy showed erythrocytes harboring Theileria like structures in 11 blood samples. Examination of 50 microscopic fields showed 57 % sensitivity and 99 % specificity compared to 100 % sensitivity and specificity for PCR. The ? coefficient between PCR and Microscopy (50 fields) techniques indicated no level of agreement. Our results showed that the microscopic examination remains the convenient technique for day-to-day diagnosis of clinical cases in the laboratory but for the detection of carrier animal containing low parasitemia. Therefore, molecular methods such as PCR can be used as a safe method for identifying cattle persistently infected with Theileria spp. PMID:24505180

  16. 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

  17. Advances and challenges in the molecular biology and treatment of glioblastoma—is there any hope for the future?

    PubMed Central

    Veliz, Ignacio; Loo, Yong; Castillo, Omar; Karachaliou, Niki; Nigro, Olga

    2015-01-01

    Malignant gliomas, such as glioblastoma multiforme (GBM), present some of the greatest challenges in the management of cancer patients worldwide. Even with aggressive surgical resections and recent advances in radiotherapy and chemotherapy, the prognosis for GBM patients remains dismal and quality of life is poor. Although new molecular pathways crucial to the biology and invasive ability of GBM are coming to light, translation of basic science achievements into clinical practice is slow. Optimal management requires a multidisciplinary approach and knowledge of potential complications arising from both disease and treatment. To help illustrate “where we are going” with GBM, we here include a detailed depiction of the molecular alterations underlying this fatal disease, as well as intensive research over the past two decades that has led to considerable advances in the understanding of basic GBM biology, pathogenesis and therapeutic approaches. PMID:25705639

  18. Probing the interaction of anthraquinone with DNA by spectroscopy, molecular modeling and cancer cell imaging technique.

    PubMed

    Yang, Lei; Fu, Zheng; Niu, Xiaoqing; Zhang, Guisheng; Cui, Fengling; Zhou, Chunwu

    2015-05-25

    A new anthraquinone derivative, (E)-2-(1-(4,5-dihydroxy-6-(hydroxymethyl)-tetrahydro-2H-pyran-2-yloxyimino)ethyl)-1,4-dihydroxyanthracene-9,10-dione (AODGlc), was synthesized and its binding properties towards DNA were explored under physiological conditions by fluorescence spectroscopy, DNA melting as well as docking techniques. The experimental results revealed that AODGlc could bind to calf thymus DNA (ctDNA) through intercalation between DNA base pairs. The values of thermodynamic parameters at different temperatures including ?G, ?H, and ?S and the molecular modeling study implied that hydrophobic interactions and hydrogen bonds were the main interactions in the AODGlc-ctDNA system. Cervical cancer cells (HepG2 cells) were used in cell viability assay and cell imaging experiment. AODGlc could interact with HepG2 cells and kill HepG2 cells under high concentration with nice curative effect, indicating its potential bioapplication in the future. PMID:25834985

  19. Synthesis and Bioconjugation of Gold Nanoparticles as Potential Molecular Probes for Light-Based Imaging Techniques

    PubMed Central

    Rayavarapu, Raja Gopal; Petersen, Wilma; Ungureanu, Constantin; Post, Janine N.; van Leeuwen, Ton G.; Manohar, Srirang

    2007-01-01

    We have synthesized and characterized gold nanoparticles (spheres and rods) with optical extinction bands within the “optical imaging window.” The intense plasmon resonant driven absorption and scattering peaks of these nanoparticles make them suitable as contrast agents for optical imaging techniques. Further, we have conjugated these gold nanoparticles to a mouse monoclonal antibody specific to HER2 overexpressing SKBR3 breast carcinoma cells. The bioconjugation protocol uses noncovalent modes of binding based on a combination of electrostatic and hydrophobic interactions of the antibody and the gold surface. We discuss various aspects of the synthesis and bioconjugation protocols and the characterization results of the functionalized nanoparticles. Some proposed applications of these potential molecular probes in the field of biomedical imaging are also discussed. PMID:18354723

  20. Congenital candidiasis: confirmation of mother-neonate transmission using molecular analysis techniques.

    PubMed

    Tiraboschi, Iris Carla Niveyro; Niveyro, Carla; Mandarano, Ana Maria; Messer, Shawn A; Bogdanowicz, Elizabeth; Kurlat, Isabel; Lasala, María Beatriz

    2010-02-01

    We describe a case of congenital acquired candidiasis in a preterm female delivered through Caesarean section due to the premature rupture of the amniotic membrane. The neonate presented with suspected chorioamnionitis and erythematous desquamative skin. Candida albicans was isolated from the placenta, mouth, groin, and periumbilical lesions. The infant developed candidemia due to Candida albicans and the same yeast was also isolated from a catheter. Culture inoculated with swabs from the mouth and vagina of the mother yielded C. albicans and C. krusei. All C. albicans isolates from the mother and the neonate were visually indistinguishable by molecular typing techniques which included chromosomal karyotyping and restriction endonuclease analysis followed by pulsed-field gel electrophoresis. These findings allowed the clinical condition to be confirmed as congenital acquisition of candidiasis in this case. PMID:19306215

  1. The Application of Molecular Techniques to the Study of Wastewater Treatment Systems

    NASA Astrophysics Data System (ADS)

    Wojnowska-Bary?a, Irena; Cydzik-Kwiatkowska, Agnieszka; Zieli?ska, Magdalena

    Wastewater treatment systems tend to be engineered to select for a few functional microbial groups that may be organized in various spatial structures such as activated sludge flocs, biofilm or granules and represented by single coherent phylogenic groups such as ammonia-oxidizing bacteria (AOB) and polyphosphate-accumulating organisms (PAO). In order to monitor and control engineered microbial structure in wastewater treatment systems, it is necessary to understand the relationships between the microbial community structure and the process performance. This review focuses on bacterial communities in wastewater treatment processes, the quantity of microorganisms and structure of microbial consortia in wastewater treatment bioreactors. The review shows that the application of molecular techniques in studies of engineered environmental systems has increased our insight into the vast diversity and interaction of microorganisms present in wastewater treatment systems.

  2. Selective extraction of lamivudine in human serum and urine using molecularly imprinted polymer technique.

    PubMed

    Shekarchi, Maryam; Pourfarzib, Mojgan; Akbari-Adergani, Behrouz; Mehramizi, Ali; Javanbakht, Mehran; Dinarvand, Rassoul

    2013-07-15

    In this work, a novel technique is described for determination of lamivudine in biological fluids by molecularly imprinted polymers (MIPs) as the sample clean-up method joint with high performance liquid chromatography (HPLC). MIPs were prepared using methacrylic acid as functional monomer, ethylene glycol dimethacrylate as crosslinker, acetonitrile and tetrahydrofuran as porogen and lamivudine as the template molecule. The new imprinted polymer was used as a molecular sorbent for the separation of lamivudine from human serum and urine. Molecular recognition properties, binding capacity and selectivity of the MIPs were evaluated and the results showed that the obtained MIPs have a high affinity for lamivudine in aqueous medium. HPLC analyses showed that the extraction of lamivudine from serum and urine by MIPs had a linear calibration curve in the range of 60-700?g/L with excellent precisions of 2.73% for serum and 2.60% for urine. The limit of detection and quantization of lamivudine was 19.34 and 58.6?g/L in serum and 7.95 and 24.05?g/L in urine respectively. MIP extraction provided about 10 fold LOQ improvement in serum and 5 fold LOQ improvement in urine samples. The recoveries of lamivudine in serum and urine samples were found to be 84.2-93.5% and 82.5-90.8% respectively. Due to the high precision and accuracy, this method may be the UV-HPLC choice with MIP extraction for bioequivalence analysis of lamivudine in serum and urine. PMID:23764731

  3. Soft X-ray microscopy and spectroscopy at the molecular environmental science beamline at the Advanced Light Source

    Microsoft Academic Search

    Hendrik Bluhm; Klas J. Andersson; Tohru Araki; Karim Benzerara; Gordon E. Brown; Jay J. Dynes; Sutapa Ghosal; Mary K. Gilles; Hans C. Hansen; J. C. Hemminger; Adam P. Hitchcock; Guido Ketteler; Arthur L. Kilcoyne; Eric M. Kneedler; John R. Lawrence; Gary G. Leppard; Juraj Majzlam; B. S. Mun; Satish C. Myneni; Anders R. Nilsson; Hirohito Ogasawara; D. F. Ogletree; Klaus H. Pecher; Miquel B. Salmeron; David K. Shuh; Brian Tonner; Tolek Tyliszczak; Tony Warwick; T. H. Yoon

    2006-01-01

    We present examples of the application of synchrotron-based spectroscopies and microscopies to environmentally relevant samples. The experiments were performed at the molecular environmental science beamline (11.0.2) at the Advanced Light Source, Lawrence Berkeley National Laboratory. Examples range from the study of water monolayers on Pt(111) single crystal surfaces using X-ray emission spectroscopy and the examination of alkali halide solution\\/water vapor

  4. Review Article: Role of Palliative Low-Molecular-Weight Heparin for Treating Venous Thromboembolism in Patients With Advanced Cancer

    Microsoft Academic Search

    Quy N. H. Tran

    2010-01-01

    Patients with cancer are at risk of developing venous thromboembolism ([VTE]; deep venous thrombosis, and pulmonary embolism). Although vitamin K antagonists had originally been used to treat VTE in these patients, low-molecular-weight heparins (LMWH) have been shown to be more effective and safe for patients with cancer-associated thrombosis. In cancer patients with advanced disease where curative therapy is no longer

  5. An effusive molecular beam technique for studies of polyatomic gas-surface reactivity and energy transfer.

    PubMed

    Cushing, G W; Navin, J K; Valadez, L; Johánek, V; Harrison, I

    2011-04-01

    An effusive molecular beam technique is described to measure alkane dissociative sticking coefficients, S(T(g), T(s); ?), on metal surfaces for which the impinging gas temperature, T(g), and surface temperature, T(s), can be independently varied, along with the angle of incidence, ?, of the impinging gas. Effusive beam experiments with T(g) = T(s) = T allow for determination of angle-resolved dissociative sticking coefficients, S(T; ?), which when averaged over the cos?(?)/? angular distribution appropriate to the impinging flux from a thermal ambient gas yield the thermal dissociative sticking coefficient, S(T). Nonequilibrium S(T(g), T(s); ?) measurements for which T(g) ? T(s) provide additional opportunities to characterize the transition state and gas-surface energy transfer at reactive energies. A resistively heated effusive molecular beam doser controls the T(g) of the impinging gas striking the surface. The flux of molecules striking the surface from the effusive beam is determined from knowledge of the dosing geometry, chamber pressure, and pumping speed. Separate experiments with a calibrated leak serve to fix the chamber pumping speed. Postdosing Auger electron spectroscopy is used to measure the carbon of the alkyl radical reaction product that is deposited on the surface as a result of alkane dissociative sticking. As implemented in a typical ultrahigh vacuum chamber for surface analysis, the technique has provided access to a dynamic range of roughly 6 orders of magnitude in the initial dissociative sticking coefficient for small alkanes on Pt(111). PMID:21529024

  6. 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.

  7. 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.

  8. 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.

  9. Techniques for Synthesizing Binaries to an Advanced Register/Memory Structure

    E-print Network

    Najjar, Walid A.

    -efficient hardware. However, recent synthesis methods for FPGAs utilize advanced memory structures, such as a "smart advanced register or memory structures that support data reuse, such as smart buffers [7], which are used information to determine reused memory data, and then store reused data in smart buffers, essentially reducing

  10. Advances in molecular imaging of atherosclerosis and myocardial infarction: shedding new light on in vivo cardiovascular biology

    PubMed Central

    Andia, Marcelo E.; Shah, Ajay M.; Botnar, René M.

    2012-01-01

    Molecular imaging of the cardiovascular system heavily relies on the development of new imaging probes and technologies to facilitate visualization of biological processes underlying or preceding disease. Molecular imaging is a highly active research discipline that has seen tremendous growth over the past decade. It has broadened our understanding of oncologic, neurologic, and cardiovascular diseases by providing new insights into the in vivo biology of disease progression and therapeutic interventions. As it allows for the longitudinal evaluation of biological processes, it is ideally suited for monitoring treatment response. In this review, we will concentrate on the major accomplishments and advances in the field of molecular imaging of atherosclerosis and myocardial infarction with a special focus on magnetic resonance imaging. PMID:23064836

  11. 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

  12. 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.

  13. The Kinetochore Moves Ahead: Contributions of Molecular and Genetic Techniques to Our Understanding of Mitosis

    NSDL National Science Digital Library

    Mary Kathrine Johnson (Mississippi State University; Department of Biological Sciences)

    2009-12-01

    Cell division is necessary to the building of a soma from the single-celled zygote during development, as well as the sine qua non, in the form of meiosis, for the evolutionary success of species. Here we review recent progress in our understanding of a key player, the kinetochore, in these processes. The kinetochore is both the anchor to the mitotic spindle for chromosomes at division and the motor for distribution of chromosomal units to daughter cells. In addition, the kinetochore plays a key role in the molecular checkpoints of cell-cycle progression. Although the nucleation of the kinetochore at a chromosomal site is under epigenetic control, the underlying base sequence of the DNA at the centromere is not critical: The assembly of the kinetochore occurs at exactly the same place on the same chromosomes at every division cycle. We discuss recent advances in our understanding of how the kinetochore is organized and assembled, as well as how it contributes to critical cell-cycle checkpoints and to chromosome movement.

  14. Nanomechanical testing technique for millimeter-sized and smaller molecular crystals.

    PubMed

    Maughan, Michael R; Carvajal, M Teresa; Bahr, David F

    2015-05-30

    Large crystals are used as a control for the development of a mounting and nanoindentation testing technique for millimeter-sized and smaller molecular crystals. Indentation techniques causing either only elastic or elastic-plastic deformation produce similar results in assessing elastic modulus, however, the elastic indents are susceptible to surface angle and roughness effects necessitating larger sample sizes for similar confidence bounds. Elastic-plastic indentations give the most accurate results and could be used to determine the different elastic constants for anisotropic materials by indenting different crystal faces, but not by rotating the indenter about its axis and indenting the same face in a different location. The hardness of small and large crystals is similar, suggesting that defect content probed in this study is similar, and that small crystals can be compared directly to larger ones. The Young's modulus and hardness of the model test material, griseofulvin, are given for the first time to be 11.5GPa and 0.4GPa respectively. PMID:25839412

  15. Chloride molecular doping technique on 2D materials: WS2 and MoS2.

    PubMed

    Yang, Lingming; Majumdar, Kausik; Liu, Han; Du, Yuchen; Wu, Heng; Hatzistergos, Michael; Hung, P Y; Tieckelmann, Robert; Tsai, Wilman; Hobbs, Chris; Ye, Peide D

    2014-11-12

    Low-resistivity metal-semiconductor (M-S) contact is one of the urgent challenges in the research of 2D transition metal dichalcogenides (TMDs). Here, we report a chloride molecular doping technique which greatly reduces the contact resistance (Rc) in the few-layer WS2 and MoS2. After doping, the Rc of WS2 and MoS2 have been decreased to 0.7 k?·?m and 0.5 k?·?m, respectively. The significant reduction of the Rc is attributed to the achieved high electron-doping density, thus a significant reduction of Schottky barrier width. As a proof-of-concept, high-performance few-layer WS2 field-effect transistors (FETs) are demonstrated, exhibiting a high drain current of 380 ?A/?m, an on/off ratio of 4 × 10(6), and a peak field-effect mobility of 60 cm(2)/(V·s). This doping technique provides a highly viable route to diminish the Rc in TMDs, paving the way for high-performance 2D nanoelectronic devices. PMID:25310177

  16. [Recent advances of anastomosis techniques of esophagojejunostomy after laparoscopic totally gastrectomy in gastric tumor].

    PubMed

    Li, Xi; Ke, Chongwei

    2015-05-25

    The esophageal jejunum anastomosis of the digestive tract reconstruction techniques in laparoscopic total gastrectomy includes two categories: circular stapler anastomosis techniques and linear stapler anastomosis techniques. Circular stapler anastomosis techniques include manual anastomosis method, purse string instrument method, Hiki improved special anvil anastomosis technique, the transorally inserted anvil(OrVil(TM)) and reverse puncture device technique. Linear stapler anastomosis techniques include side to side anastomosis technique and Overlap side to side anastomosis technique. Esophageal jejunum anastomosis technique has a wide selection of different technologies with different strengths and the corresponding limitations. This article will introduce research progress of laparoscopic total gastrectomy esophagus jejunum anastomosis from both sides of the development of anastomosis technology and the selection of anastomosis technology. PMID:26013872

  17. 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

  18. Advances in analytical techniques for polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and dioxin-like PCBs

    PubMed Central

    Clement, Ray E.; Okey, Allan B.; Marvin, Chris H.

    2006-01-01

    Analytical techniques for the determination of polychorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF) and dioxin-like PCBs (DLPCB) are reviewed. The focus of the review is on recent advances in methodology and analytical procedures. The paper also reviews toxicology, the development of toxic equivalent factors (TEF) and the determination of toxic equivalent quantity (TEQ) values. Sources, occurrence and temporal trends of PCDD/PCDF are summarized to provide examples of levels and concentration ranges for the methods and techniques reviewed. PMID:16794816

  19. Device degradation behavior and polysilicon film morphology of thin film transistors fabricated using advanced excimer laser lateral solidification techniques

    Microsoft Academic Search

    D. N. Kouvatsos; A. T. Voutsas; L. Michalas; F. V. Farmakis; G. J. Papaioannou

    2007-01-01

    The degradation of polysilicon thin film transistors fabricated in films obtained using variations of advanced through-mask excimer laser anneal sequential lateral solidification (SLS) schemes was investigated. The morphology and grain structure of these 50 nm thick polysilicon films was studied using SEM and AFM. Very elongated or square-like polycrystalline silicon grains were observed, as shaped by each crystallization technique. Hot carrier

  20. Investigation of Advanced Dose Verification Techniques for External Beam Radiation Treatment

    NASA Astrophysics Data System (ADS)

    Asuni, Ganiyu Adeniyi

    Intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) have been introduced in radiation therapy to achieve highly conformal dose distributions around the tumour while minimizing dose to surrounding normal tissues. These techniques have increased the need for comprehensive quality assurance tests, to verify that customized patient treatment plans are accurately delivered during treatment. in vivo dose verification, performed during treatment delivery, confirms that the actual dose delivered is the same as the prescribed dose, helping to reduce treatment delivery errors. in vivo measurements may be accomplished using entrance or exit detectors. The objective of this project is to investigate a novel entrance detector designed for in vivo dose verification. This thesis is separated into three main investigations, focusing on a prototype entrance transmission detector (TRD) developed by IBA Dosimetry, Germany. First contaminant electrons generated by the TRD in a 6 MV photon beam were investigated using Monte Carlo (MC) simulation. This study demonstrates that modification of the contaminant electron model in the treatment planning system is required for accurate patient dose calculation in buildup regions when using the device. Second, the ability of the TRD to accurately measure dose from IMRT and VMAT was investigated by characterising the spatial resolution of the device. This was accomplished by measuring the point spread function with further validation provided by MC simulation. Comparisons of measured and calculated doses show that the spatial resolution of the TRD allows for measurement of clinical IMRT fields within acceptable tolerance. Finally, a new general research tool was developed to perform MC simulations for VMAT and IMRT treatments, simultaneously tracking dose deposition in both the patient CT geometry and an arbitrary planar detector system, generalized to handle either entrance or exit orientations. It was demonstrated that the tool accurately simulates dose to the patient CT and planar detector geometries. The tool has been made freely available to the medical physics research community to help advance the development of in vivo planar detectors. In conclusion, this thesis presents several investigations that improve the understanding of a novel entrance detector designed for patient in vivo dosimetry.

  1. 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...

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

    E-print Network

    Sparks, Donald L.

    . Contamination of soils and waters with metals, oxyanions, radionuclides, nutri~nts, and organic chemicals and elucidate contaminant retention/release mechanisms in soils and on soil components. Applications-ray absorption spectroscopic and chemical mapping techniques allow one to speciate metal contaminants in soils

  3. 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.

  4. The impulse resistance welding: A new technique for joining advanced thermoplastic composite parts

    SciTech Connect

    Arias, M.; Ziegmann, G.

    1996-12-31

    Welding is a joining technique suitable for thermoplastic composites. This paper presents the development of a new, fast joining technique, which is based on the common resistance welding process. Heat is introduced by using electrical power pulses into the heating area and therefore this technique was called the Impulse Resistance Welding (IRW). The new technique will be described and discussed and the application of this technique by joining ribs to the skin of an aerodynamic spoiler part is demonstrated. The potential of an automation of the Impulse resistance welding process will be shown. Carbon fibre /PEEK (APC-2/AS4) has been selected as the material both for the skin and the rib.

  5. Microbial diversity in soil: ecological theories, the contribution of molecular techniques and the impact of transgenic plants and transgenic microorganisms

    Microsoft Academic Search

    J. M. Lynch; A. Benedetti; H. Insam; M. P. Nuti; K. Smalla; V. Torsvik; P. Nannipieri

    2004-01-01

    This review mainly discusses three related topics: the application of ecological theories to soil, the measurement of microbial diversity by molecular techniques and the impact of transgenic plants and microorganisms on genetic diversity of soil. These topics were debated at the Meeting on Soil Emergency held in Erice (Trapani, Italy) in 2001 for the celebration of the 50th anniversary of

  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. 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.

  8. Comparison of the utility of barley retrotransposon families for genetic analysis by molecular marker techniques.

    PubMed

    Leigh, F; Kalendar, R; Lea, V; Lee, D; Donini, P; Schulman, A H

    2003-07-01

    The Sequence-Specific Amplification Polymorphism (S-SAP) method, and the related molecular marker techniques IRAP (inter-retrotransposon amplified polymorphism) and REMAP (retrotransposon-microsatellite amplified polymorphism), are based on retrotransposon activity, and are increasingly widely used. However, there have been no systematic analyses of the parameters of these methods or of the utility of different retrotransposon families in producing polymorphic, scorable fingerprints. We have generated S-SAP, IRAP, and REMAP data for three barley (Hordeum vulgare L.) varieties using primers based on sequences from six retrotransposon families (BARE-1, BAGY-1, BAGY-2, Sabrina, Nikita and Sukkula). The effect of the number of selective bases on the S-SAP profiles has been examined and the profiles obtained with eight MseI+3 selective primers compared for all the elements. Polymorphisms detected in the insertion pattern of all the families show that each can be used for S-SAP. The uniqueness of each transposition event and differences in the historic activity of each family suggest that the use of multiple retrotransposon families for genetic analysis will find applications in mapping, fingerprinting, and marker-assisted selection and evolutionary studies, not only in barley and other Hordeum species and related taxa, but also more generally. PMID:12768410

  9. The impact of molecular morphology techniques on the expert diagnosis in melanocytic skin neoplasms.

    PubMed

    Ferrara, Gerardo; Misciali, Cosimo; Brenn, Thomas; Cerroni, Lorenzo; Kazakov, Dmitry W; Perasole, Antonio; Russo, Rosa; Ricci, Roberto; Crisman, Giuliana; Fanti, Pier Alessandro; Passarini, Beatrice; Patrizi, Annalisa

    2013-10-01

    Thirteen melanocytic skin neoplasms with a consultation diagnosis by A. Bernard Ackerman were submitted to immunohistochemistry for HMB-45, Ki67, cyclin D1, e-cadherin, and p16; 9/13 cases underwent fluorescence in situ hybridization (FISH) test targeting 6p25 (RREB1), 6q23 (MYB), centromere 6 (Cep6), and 11q13 (CCND1), as well as the centromere 7 (Cep7). A "consensus diagnosis" among 3 experts was also advocated both before and after morphomolecular information. Three neoplasms with a consultation diagnosis of Spitz nevus showed at least 3 abnormal immunohistochemical patterns; 2 of these cases were also FISH-positive for CCND1 gain, but none of them had a final consensus diagnosis of melanoma. Two neoplasms with a consultation diagnosis of congenital nevus received a consensus diagnosis of melanoma. Molecular morphology techniques can highlight the atypical features of melanocytic neoplasms and support existence of a morphobiologic "spectrum": This should be mirrored in the final report by abandoning the dichotomic (benign vs malignant) diagnostic approach. PMID:23775023

  10. Advances in the understanding of the clinically relevant genetic pathways and molecular aspects of canine mammary tumours: Part 1. Proliferation, apoptosis and DNA repair.

    PubMed

    Matos, A J F; Santos, A A

    2015-08-01

    There have been significant recent advances in the understanding of the molecular events and critical pathways associated with and driving cancer of the mammary gland in humans and dogs. The study of canine mammary tumour biology, particularly of the molecular events associated with proliferation, cell survival, invasion and metastasis, is crucial for the development of effective therapeutic agents and strategies. In this first part of a two-part review, recent advances in the understanding of the clinically relevant genetic and molecular pathways driving cell proliferation, apoptosis and DNA repair in canine mammary gland tumours are described. PMID:25744808

  11. [National survey of the infrastructure of research centers in advanced biotechnology and molecular epidemiology in Mexico].

    PubMed

    Sartí, E; Orozco, S; Dorman, J; Tapia, R; Gorodezky, C

    1997-01-01

    An International Molecular Epidemiology Task Force group (IMETAF) was established in 1993, where the Mexican group include as their objectives: the evaluation of the main public health problems that could be improvement through molecular epidemiology; the analysis of the interaction between molecular biology and epidemiology; development of international nets of collaboration and the establishment of surveys toward the prevention and control of some diseases. As part of a general strategy the Mexican scientific committee developed the first national infrastructure survey of the centers of biotechnology and molecular epidemiology. This survey obtained data trough a questionnaire of the general characteristics the development of the molecular epidemiology, the main tools of surveys, equipment, material and reagents, the personnel trained in biotechnology, epidemiology and public health, the needs of training, the national and international nets, how to develop molecular epidemiology and areas to be considered. The results give a general idea of the possibilities to develop the field in Mexico. More than 50% are currently working in this theme. The majority in infectious diseases. The centers have the equipment, material reagents and human resources well trained to incorporate the molecular epidemiology in their usual work. They reported the need of technology transfer to develop collaborations and courses, symposia or congresses. We conclude that Mexico has the capability and the infrastructure to develop molecular epidemiology. A survey is needed on animals. PMID:9504100

  12. Development of heat transfer enhancement techniques for external cooling of an advanced reactor vessel

    NASA Astrophysics Data System (ADS)

    Yang, Jun

    Nucleate boiling is a well-recognized means for passively removing high heat loads (up to ˜106 W/m2) generated by a molten reactor core under severe accident conditions while maintaining relatively low reactor vessel temperature (<800 °C). With the upgrade and development of advanced power reactors, however, enhancing the nucleate boiling rate and its upper limit, Critical Heat Flux (CHF), becomes the key to the success of external passive cooling of reactor vessel undergoing core disrupture accidents. In the present study, two boiling heat transfer enhancement methods have been proposed, experimentally investigated and theoretically modelled. The first method involves the use of a suitable surface coating to enhance downward-facing boiling rate and CHF limit so as to substantially increase the possibility of reactor vessel surviving high thermal load attack. The second method involves the use of an enhanced vessel/insulation design to facilitate the process of steam venting through the annular channel formed between the reactor vessel and the insulation structure, which in turn would further enhance both the boiling rate and CHF limit. Among the various available surface coating techniques, metallic micro-porous layer surface coating has been identified as an appropriate coating material for use in External Reactor Vessel Cooling (ERVC) based on the overall consideration of enhanced performance, durability, the ease of manufacturing and application. Since no previous research work had explored the feasibility of applying such a metallic micro-porous layer surface coating on a large, downward facing and curved surface such as the bottom head of a reactor vessel, a series of characterization tests and experiments were performed in the present study to determine a suitable coating material composition and application method. Using the optimized metallic micro-porous surface coatings, quenching and steady-state boiling experiments were conducted in the Sub-scale Boundary Layer Boiling (SBLB) test facility at Penn State to investigate the nucleate boiling and CHF enhancement effects of the surface coatings by comparing the measurements with those for a plain vessel without coatings. An overall enhancement in nucleate boiling rates and CHF limits up to 100% were observed. Moreover, combination of data from quenching experiments and steady-state experiments produced new sets of boiling curves, which covered both the nucleate and transient boiling regimes with much greater accuracy. Beside the experimental work, a theoretical CHF model has also been developed by considering the vapor dynamics and the boiling-induced two-phase motions in three separate regions adjacent to the heating surface. The CHF model is capable of predicting the performance of micro-porous coatings with given particle diameter, porosity, media permeability and thickness. It is found that the present CHF model agrees favorably with the experimental data. Effects of an enhanced vessel/insulation structure on the local nucleate boiling rate and CHF limit have also been investigated experimentally. It is observed that the local two-phase flow quantities such as the local void fraction, quality, mean vapor velocity, mean liquid velocity, and mean vapor and liquid mass flow rates could have great impact on the local surface heat flux as boiling of water takes place on the vessel surface. An upward co-current two-phase flow model has been developed to predict the local two-phase flow behavior for different flow channel geometries, which are set by the design of insulation structures. It is found from the two-phase flow visualization experiments and the two-phase flow model calculations that the enhanced vessel/insulation structure greatly improved the steam venting process at the minimum gap location compared to the performance of thermal insulation structures without enhancement. Moveover, depending on the angular location, steady-state boiling experiments with the enhanced insulation design showed an enhancement of 1.8 to 3.0 times in the local critical h

  13. Assessment of Improved Organ at Risk Sparing for Advanced Cervix Carcinoma Utilizing Precision Radiotherapy Techniques

    Microsoft Academic Search

    Dietmar Georg; Petra Georg; Martin Hillbrand; Richard Pötter; Ulrike Mock

    2008-01-01

    \\u000a \\u000a Purpose:\\u000a   To evaluate the potential benefit of proton therapy and photon based intensity-modulated radiotherapy in comparison to 3-D\\u000a conformal photon radiotherapy (3D-CRT) in locally advanced cervix cancer.\\u000a \\u000a \\u000a \\u000a \\u000a Patients and Methods:\\u000a   In five patients with advanced cervix cancer 3D-CRT (four-field box) was compared with intensity modulated photon (IMXT) and\\u000a proton therapy (IMPT) as well as proton beam therapy (PT) based on

  14. Beyond whole-body imaging: advanced imaging techniques of PET/MRI.

    PubMed

    Barnwell, James; Raptis, Constantine A; McConathy, Jonathan E; Laforest, Richard; Siegel, Barry A; Woodard, Pamela K; Fowler, Kathryn

    2015-02-01

    PET/MRI is a hybrid imaging modality that is gaining clinical interest with the first Food and Drug Administration-approved simultaneous imaging system recently added to the clinical armamentarium. Several advanced PET/MRI applications, such as high-resolution anatomic imaging, diffusion-weighted imaging, motion correction, and cardiac imaging, show great potential for clinical use. The purpose of this article is to highlight several advanced PET/MRI applications through case examples and review of the current literature. PMID:25188648

  15. Oncoplastic technique in breast conservative surgery for locally advanced breast cancer

    PubMed Central

    Kongdan, Youwanush; Vassanasiri, Wichai; Ratchaworapong, Kampol; Sukarayothin, Thongchai; Supsamutchai, Chairat; Klaiklern, Phatarachate; Leesombatpaiboon, Monchai; Hamza, Alaa; Zurrida, Stefano

    2014-01-01

    Locally advanced breast cancer (LABC) should be taken into decision making when planning breast conservative surgery, but this procedure should be done on the principle of oncologic safety in order to achieve negative surgical margin and maintain aesthetic result. This procedure should be offered as the choice of treatment in selected patients. PMID:25083490

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

    Microsoft Academic Search

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

    2012-01-01

    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

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

    E-print Network

    Meeden, Lisa A.

    of the oldest and most versatile algorithms for machine learning. Academics and industry professionals have advances in "deep learning" are the most notable ex- ception. Neural nets can also suffer from the issue was that learning how to make use of this expert knowledge would prove an easier task than learning the problem from

  18. 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-manipulator mobile work cell is underway. This cell is supported and enha...

  19. Recent Advance of Hydride Generation–Analytical Atomic Spectrometry: Part I—Technique Development

    Microsoft Academic Search

    Zhou Long; Yamin Luo; Chengbin Zheng; Pengchi Deng; Xiandeng Hou

    2012-01-01

    Hydride generation is the most popular and widely used chemical vapor generation technique and is interesting to analytical chemists as an effective sample introduction method, especially for elemental determination and speciation analysis by analytical atomic spectrometry. The present review provides a literature survey on the hydride generation technique coupled to analytical atomic spectrometry during the past several years, covering the

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

    SciTech Connect

    Williams, R.G.D. (GEC Alsthom Turbine Generator Ltd., Stafford (United Kingdom)); Yang, S.J. (Heriot-Watt Univ., Edinburgh (United Kingdom))

    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.

  1. Microprobing the molecular spatial distribution and structural architecture of feed-type sorghum seed tissue (Sorghum Bicolor L.) using the synchrotron radiation infrared microspectroscopy technique.

    PubMed

    Yu, Peiqiang

    2011-09-01

    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 ?1725 (carbonyl C=O ester), 1650 (amide I), 1657 (protein secondary structure ?-helix), 1628 (protein secondary structure ?-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(3) anti-symmetric), 2929 (CH(2) anti-symmetric), 2877 (CH(3) symmetric) and 2848?cm(-1) (CH(2) asymmetric)]. The relative protein secondary structure ?-helix to ?-sheet ratio image, protein amide I to starch granule ratio image, and anti-symmetric CH(3) to CH(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. PMID:21862861

  2. 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.

  3. Identification of yeasts associated with milk products using traditional and molecular techniques.

    PubMed

    Lopandic, K; Zelger, S; Bánszky, L K; Eliskases-Lechner, F; Prillinger, H

    2006-06-01

    An integrated approach including phenotypic (morphological, biochemical and physiological characterization) and genotypic (RAPD-PCR, sequencing of D1/D2 domain of 26S rRNA encoding gene) methods was used for the identification of yeasts isolated from different milk products. There were 513 isolates in all, 460 ascomycetous and 53 basidiomycetous yeasts. The yeast isolates were characterized on the basis of their biochemical and physiological properties, and the D1/D2 domain of 26S rDNA was sequenced in selected strains. Relying on the obtained results from both the data-sets, corresponding type strains were selected and compared with the respective yeast isolates from milk products by RAPD fingerprinting. The strains showing a degree of similarity >80% were considered conspecific. By means of the applied techniques it was possible to identify 92% yeast isolates at species level. Debaryomyces hansenii, Geotrichum candidum, Kluyveromyces marxianus, Yarrowia lipolytica and Candida zeylanoides are the most frequently isolated species. The majority of the yeasts were isolated from fresh and sour curd cheese. A comparison of the results obtained by phenotypic and genotypic investigation revealed that the identification based on classical methods was supported by genotypic characterization in only 54% of examined isolates. The results described in this work show that the applied molecular identification is a reliable approach to the identification of yeasts associated with milk products in contrast to the conventional biochemical and physiological tests. The identification of new yeast species requires additional genetic markers such as sequencing of different genes or DNA:DNA hybridization. PMID:16943023

  4. Understanding the interaction between valsartan and detergents by NMR techniques and molecular dynamics simulation.

    PubMed

    Cao, Chenyu; Mao, Jiezhen; Li, Fang; Yang, Minghui; He, Hongqing; Jiang, Ling; Liu, Maili

    2012-06-28

    Valsartan (VST) is one of the Angiotensin II receptor antagonists, which is widely used in clinical hypertension treatment. It is believed that VST incorporates into biological membranes before it binds to AT(1) receptor. Herein the interactions between VST and detergents, mimicking the membrane environment, were investigated by using nuclear magnetic resonance (NMR) techniques and molecular dynamics (MD) simulation. We observed that VST has two conformers (trans and cis) exchanging slowly in DPC (dodecyl-phosphocholine) micelles, a widely used detergent. The changes of chemical shifts, relaxation rates, and self-diffusion coefficients of VST protons indicate that both conformers have strong interactions with DPC. NOE cross peaks and MD simulation reveal that DPC interacts with VST not only through the hydrophobic lipid chain, but also the hydrophilic headgroup, locating VST at the charged headgroup and upper part of the micelles. Our results are in good agreement with the Raman spectroscopic studies of VST in the DPPC (dipalmitoyl-phosphatidylcholine) bilayers by Potamitis et al. (Biochim. Biophys. Acta. 2011). The concentration ratio of trans over cis conformers is 0.94, showing that two conformers have the same affinities with the detergent, which is significantly smaller than our previous results obtained in SDS (sodium dodecyl sulfate) micelles. MD simulation suggested that the cis conformer has slightly lower binding free energy than the trans conformer when interacting with DPC. The conformational change of VST was further investigated in two detergents, CTAB (hexadecyltrimethylammonium bromide) and Tween-20 (polysorbate 20). Ratios of conformer A and B in the presence of detergents are in the order of DPC, CTAB < Tween-20 < SDS, which is correlated with the charge characters of their head groups. NMR investigations and MD simulations indicate that the electrostatic interaction plays an essential role in the binding process of VST with detergents, and the hydrophobic interaction influences the packing of the drug in the micelles. These results may be of help in understanding delivery processes of sartan drugs in cell membranes. PMID:22708715

  5. 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

  6. New techniques for the design of advanced ultrasonic transducers for wire bonding

    Microsoft Academic Search

    Lorenzo Parrini

    2003-01-01

    A new high-frequency ultrasonic transducer, in particular for the application wire-bonding, has been conceived, designed, prototyped, and tested. In the design phase an advanced approach was used and established. The method is based on the two basic principles of modularity and iteration. The transducer is decomposed in its elementary components. For each component an initial draft is obtained with finite-elements-method

  7. Advanced real-time dynamic scene generation techniques for improved performance and fidelity

    Microsoft Academic Search

    Mark H. Bowden; James A. Buford; Anthony J. Mayhall

    2000-01-01

    Recent advances in real-time synthetic scene generation for Hardware-in-the-loop (HWIL) testing at the U.S. Army Aviation and Missile Command (AMCOM) Aviation and Missile Research, Development, and Engineering Center (AMRDEC) improve both performance and fidelity. Modeling ground target scenarios requires tradeoffs because of limited texture memory for imagery and limited main memory for elevation data. High- resolution insets have been used

  8. 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 ...

  9. 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...

  10. Advances in vegetation management for power line corridor monitoring using aerial remote sensing techniques

    Microsoft Academic Search

    Zhengrong Li; Rodney Walker; Ross Hayward; Luis Mejias

    2010-01-01

    This paper presents a comprehensive discussion of vegetation management approaches in power line corridors\\u000abased on aerial remote sensing techniques. We address three\\u000aissues 1) strategies for risk management in power line corridors, 2) selection of suitable platforms and sensor suite for data collection and 3) the progress in automated data processing techniques for vegetation management. We present initial results

  11. ac surface discharge on dielectric materials observed by advanced Pockels effect technique

    Microsoft Academic Search

    Toshiyuki Kawasaki; Tokihiro Terashima; Saburo Suzuki; Tatsuo Takada

    1994-01-01

    Techniques for visualization and quantification of the latent electric charge image on dielectric materials have been developed using Pockels effect of a BSO (Bi12SiO20) single crystal, a charge coupled device camera recording system, and a computer image processing technique. The Pockels device of the BSO single crystal was used as a transducer to transfer the surface charge density to retard

  12. 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.

  13. An overview on in situ micronization technique – An emerging novel concept in advanced drug delivery

    PubMed Central

    Vandana, K.R.; Prasanna Raju, Y.; Harini Chowdary, V.; Sushma, M.; Vijay Kumar, N.

    2013-01-01

    The use of drug powders containing micronized drug particles has been increasing in several pharmaceutical dosage forms to overcome the dissolution and bioavailability problems. Most of the newly developed drugs are poorly water soluble which limits dissolution rate and bioavailability. The dissolution rate can be enhanced by micronization of the drug particles. The properties of the micronized drug substance such as particle size, size distribution, shape, surface properties, and agglomeration behaviour and powder flow are affected by the type of micronization technique used. Mechanical communition, spray drying and supercritical fluid (SCF) technology are the most commonly employed techniques for production of micronized drug particles but the characteristics of the resulting drug product cannot be controlled using these techniques. Hence, a newer technique called in situ micronization is developed in order to overcome the limitations associated with the other techniques. This review summarizes the existing knowledge on in situ micronization techniques. The properties of the resulting drug substance obtained by in situ micronization were also compared. PMID:25161371

  14. Structural changes of humic acids from sinking organic matter and surface sediments investigated by advanced solid-state NMR: Insights into sources, preservation and molecularly uncharacterized components

    NASA Astrophysics Data System (ADS)

    Mao, Jingdong; Tremblay, Luc; Gagné, Jean-Pierre

    2011-12-01

    Knowledge of the structural changes that particulate organic matter (POM) undergoes in natural systems is essential for determining its reactivity and fate. In the present study, we used advanced solid-state NMR techniques to investigate the chemical structures of sinking particulate matter collected at different depths as well as humic acids (HAs) extracted from these samples and underlying sediments from the Saguenay Fjord and the St. Lawrence Lower Estuary (Canada). Compared to bulk POM, HAs contain more non-polar alkyls, aromatics, and aromatic C-O, but less carbohydrates (or carbohydrate-like structures). In the two locations studied, the C and N contents of the samples (POM and HAs) decreased with depth and after deposition onto sediments, leaving N-poor but O-enriched HAs and suggesting the involvement of partial oxidation reactions during POM microbial degradation. Advanced NMR techniques revealed that, compared to the water-column HAs, sedimentary HAs contained more protonated aromatics, non-protonated aromatics, aromatic C-O, carbohydrates (excluding anomerics), anomerics, OC q, O-C q-O, OCH, and OCH 3 groups, but less non-polar alkyls, NCH, and mobile CH 2 groups. These results are consistent with the relatively high reactivity of lipids and proteins or peptides. In contrast, carbohydrate-like structures were selectively preserved and appeared to be involved in substitution and copolymerization reactions. Some of these trends support the selective degradation (or selective preservation) theory. The results provide insights into mechanisms that likely contribute to the preservation of POM and the formation of molecules that escape characterization by traditional methods. Despite the depletion of non-polar alkyls with depth in HAs, a significant portion of their general structure survived and can be assigned to a model phospholipid. In addition, little changes in the connectivities of different functional groups were observed. Substituted and copolymerized carbohydrates and fused-ring aromatics detected in the present study likely represented an important part of molecularly uncharacterized components (MUC).

  15. The GenTechnique project: developing an open environment for learning molecular genetics

    Microsoft Academic Search

    R. E Calza; J. T Meade

    1998-01-01

    The study of molecular genetics and biotechnology demands that students understand key concepts of molecular biology, such as DNA and its replication, or the synthesis of proteins. Pedagogy based on lecture and individual learning from textbooks, as commonly practiced in the U.S.A., often yields less than satisfactory results. Based upon faculty assessments of student performance and upon student course evaluations,

  16. 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.

  17. 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.

  18. 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

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

    SciTech Connect

    Smith, D.M.; Hua, D.W. [Univ. of New Mexico, Albuquerque, NM (United States). UNM/NSF Center for Micro-Engineered Ceramics; Earl, W. [Los Alamos National Lab., NM (United States)

    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).

  20. 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.

  1. Precision bone and muscle loss measurements by advanced, multiple projection DEXA (AMPDXA) techniques for spaceflight applications

    NASA Technical Reports Server (NTRS)

    Charles, H. K. Jr; Beck, T. J.; Feldmesser, H. S.; Magee, T. C.; Spisz, T. S.; Pisacane, V. L.

    2001-01-01

    An advanced, multiple projection, dual energy x-ray absorptiometry (AMPDXA) scanner system is under development. The AMPDXA is designed to make precision bone and muscle loss measurements necessary to determine the deleterious effects of microgravity on astronauts as well as develop countermeasures to stem their bone and muscle loss. To date, a full size test system has been developed to verify principles and the results of computer simulations. Results indicate that accurate predictions of bone mechanical properties can be determined from as few as three projections, while more projections are needed for a complete, three-dimensional reconstruction. c 2001. Elsevier Science Ltd. All rights reserved.

  2. 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.

  3. 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.

  4. Advanced control technique application in U-tube steam generator of nuclear power station

    Microsoft Academic Search

    Hamdi M. Mousa; Sayed M. El-araby; Magdy A. Koutb; Elsayed H. M. Ali

    2011-01-01

    A water level control system for a nuclear steam generator (SG) is proposed. A method to improve the performance of nuclear steam generator in nuclear power station is introduced. Combination of genetic algorithm (GA) technique and fuzzy logic control is carried out. The optimal parameters of fuzzy logic controller are achieved. These parameters include; the membership functions of water level

  5. Mobile and Stationary Computer Vision based Traffic Surveillance Techniques for Advanced ITS Applications

    Microsoft Academic Search

    Meng Cao

    2009-01-01

    During the past decade, new sensing technologies, such as inductive loops, laser range scanners, radar detectors and computer vision sensors have been greatly enhanced and applied to the Intelligent Transportation System (ITS) area. Among all these sensor systems, computer vision-based approaches are one of the most popular and promising techniques used in ITS for traffic evaluation and management, driver assistance,

  6. Recent Advance of Hydride Generation-Analytical Atomic Spectrometry: Part I-Technique Development

    Microsoft Academic Search

    Zhou Long; Yamin Luo; Chengbin Zheng; Pengchi Deng; Xiandeng Hou

    2012-01-01

    Hydride generation is the most popular and widely used chemical vapor generation, which is always interesting to analytical chemists as an effective sample introduction method, especially for elemental determination and speciation analysis by analytical atomic spectrometry. The present review provides a literature survey on the hydride generation technique coupled to analytical atomic spectrometry during the past several years, covering the

  7. Recent advances in singularly perturbed control systems-high accuracy techniques

    Microsoft Academic Search

    Zoran Gajic; X. Shen

    1998-01-01

    We give the summary of main results obtained in the context of singularly perturbed linear control systems within the last ten years with emphasis on the recursive approach, exact closed-loop decomposition transformation (Hamiltonian approach), and integral manifold theory-high accuracy techniques. In addition, we indicate the recent results obtained for H? optimal control and filtering, jump parameter linear systems, control of

  8. Respiratory support techniques for prematurely born infants: new advances and perspectives.

    PubMed

    Greenough, A

    2001-01-01

    A variety of respiratory techniques have been introduced into the neonatal intensive care unit. High frequency positive pressure ventilation (HFPPV) compared to slow rate ventilation significantly reduced the incidence of airleaks, but this has yet to be confirmed in infants routinely exposed to antenatal steroids and postnatal surfactant. Continuous positive airways pressure (CPAP) is useful for infants with obstructive or mixed apnoea and reduces the need for extra respiratory support following extubation, whether it reduces chronic lung disease (CLD) remains to be appropriately tested. Randomised trials have failed to identify long term benefits of patient triggered ventilation (PTV) in infants with acute respiratory distress; but it is the most efficacious mode of weaning. High volume strategy, high frequency oscillation (HFO), if commenced within 24 hours of birth, lowers the CLD rate, but may increase airleak and intracranial pathology. Nitric oxide (NO) can improve oxygenation in preterm infants with suspected pulmonary hypertension, but does not appear to influence outcome. Liquid ventilation is a promising, but relatively untested technique in preterm infants. Ventilator techniques have not been rigorously examined in infants developing or with established CLD. It is essential that the relative merits of new respiratory support techniques are compared in well designed studies which include infants with acute and chronic respiratory distress, only then can their appropriate roles in the management of prematurely born infants be identified. PMID:11550407

  9. Advances in neuroimaging techniques: implications for the shared syntactic integration resource hypothesis

    Microsoft Academic Search

    Jessica A. Grahn

    The shared syntactic integration resource hypothesis (SSIRH) generates specific predictions about neural overlap in the instantiation of processes required for syntactic integration in music and language. Syntactic integration occurs over time, through communication between areas maintaining domain-specific representations and areas responsible for domain-general processing. Analyzing neural overlap and temporal communication requires techniques that enable superior spatial resolution and localization, as

  10. Advances in hyphenated analytical techniques for shotgun proteome and peptidome analysis—A review

    Microsoft Academic Search

    Lianghai Hu; Mingliang Ye; Xiaogang Jiang; Shun Feng; Hanfa Zou

    2007-01-01

    Proteomics is defined as the analysis of part or all of the protein components of a complex biological system (a cell, organ or tissue) at a given moment. Due to the huge number of proteins encoded by the genome, novel analytical techniques must be developed to meet the need of large scale analysis. This has led to the hyphenation of

  11. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide emissions from coal-fired boilers

    SciTech Connect

    Sorge, J.N. [Southern Co. Services, Inc., Birmingham, AL (United States); Menzies, B. [Radian Corp., Austin, TX (United States); Smouse, S.M. [USDOE Pittsburgh Energy Technology Center, PA (United States); Stallings, J.W. [Electric Power Research Inst., Palo Alto, CA (United States)

    1995-09-01

    Technology project demonstrating advanced wall-fired combustion techniques for the reduction of nitrogen oxide NOx emissions from coal-fired boilers. The primary objective of the demonstration is to determine the long-term NOx reduction performance of advanced overfire air (AOFA), low NOx burners (LNB), and advanced digital control/optimization methodologies applied in a stepwise fashion to a 500 MW boiler. The focus of this paper is to report (1) on the installation of three on-line carbon-in-ash monitors and (2) the design and results to date from the advanced digital control/optimization phase of the project.

  12. High-salt diet advances molecular circadian rhythms in mouse peripheral tissues

    Microsoft Academic Search

    Hideaki Oike; Kanji Nagai; Tatsunobu Fukushima; Norio Ishida; Masuko Kobori

    2010-01-01

    Dietary compounds influence the expression of various genes and play a major role in changing physiological and metabolic states. However, little is known about the role of food ingredients in the regulation of circadian gene expression. Here, we show that feeding mice with a high-salt (HS) diet ad libitum for over 2weeks advanced the phase of clock gene expression by

  13. Marine molecular biology: An emerging field of biological sciences

    Microsoft Academic Search

    Narsinh L. Thakur; Roopesh Jain; Filipe Natalio; Bojan Hamer; Archana N. Thakur; Werner E. G. Müller

    2008-01-01

    An appreciation of the potential applications of molecular biology is of growing importance in many areas of life sciences, including marine biology. During the past two decades, the development of sophisticated molecular technologies and instruments for biomedical research has resulted in significant advances in the biological sciences. However, the value of molecular techniques for addressing problems in marine biology has

  14. Challenges to computational quantum chemistry from contemporary advances in polyatomic molecular electronic spectroscopy

    Microsoft Academic Search

    Michael Kasha; Dimitri Parthenopoulos; Barry Dellinger

    1993-01-01

    Molecular electronic spectroscopy featuring intramolecular proton transfer and twisted intramolecular charge transfer poses a whole new range of problems for computational quantum chemistry. The development of the four-level laser based on the intramolecular proton-transfer focuses on the subtleties of the interaction of the singlet and triplet electronic state manifolds of the two different tautomeric species. Examples are given of the

  15. Vibrational spectra of N2: An advanced undergraduate laboratory in atomic and molecular spectroscopy

    E-print Network

    Bayram, S. Burçin

    and engineering. Hence, the importance of atomic, molecular, and optical physics in science education cannot are instrumental not only in educating students about the quantum mechanical phenomenology ingrained concern,2 such as the photochemical formation of nitrogen oxides which catalyse the destruction

  16. Sedimentation Coefficient, Frictional Coefficient, and Molecular Weight: A Preparative Ultracentrifuge Experiment for the Advanced Undergraduate Laboratory.

    ERIC Educational Resources Information Center

    Halsall, H. B.; Wermeling, J. R.

    1982-01-01

    Describes an experiment using a high-speed preparative centrifuge and calculator to demonstrate effects of the frictional coefficient of a macromolecule on its rate of transport in a force field and to estimate molecular weight of the macromolecule using an empirical relationship. Background information, procedures, and discussion of results are…

  17. SOFTWARE REVIEW: The Advanced Physics Virtual Laboratory Series: CD-ROM Thermodynamics and Molecular Physics

    Microsoft Academic Search

    Ken Dobson

    1998-01-01

    The program installed easily although the inexperienced might be as terrified as I was by the statements threatening to delete various files it had found on my machine. However, I ignored these and all went well. The user is faced with a menu of 14 simulations covering molecular topics such as the Kinetic Model of an Ideal Gas, Diffusion (through

  18. 2013NatureAmerica,Inc.Allrightsreserved. nature structural & molecular biology advance online publication

    E-print Network

    Grubmüller, Helmut

    publication a rt i c l e s Ribosomes are molecular machines that synthesize proteins from aminoacyl ta). During translocation, tRNAs move on the 50S subunit into the hybrid A/P and P/E positions1 by the reversal of the subunit rotation, yields the post-translocation complex. Translocation is promoted

  19. 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.

  20. 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

  1. Molecular dynamics in azobenzene liquid crystal polymer films measured by time-resolved techniques.

    PubMed

    Fujii, T; Kuwahara, S; Katayama, K; Takado, K; Ube, T; Ikeda, T

    2014-06-14

    Photo-induced molecular motion in a liquid crystal polymer film including azobenzene was studied by the heterodyne transient grating method. The film was confined in a liquid crystal cell, where it is a photomobile film under free-standing conditions. By observation of the refractive index change induced by a laser pulse, contraction of the film was observed on the order of several hundreds of nanoseconds, and the subsequent reorientation and molecular rotation dynamics were observed from a few microseconds to a hundred milliseconds. Finally, the cis isomer of azobenzene was thermally returned back to the trans isomer in about ten seconds because the film could not be bent in the liquid crystal cell. Since the contraction, reorientation and molecular rotation took place before the cis to trans back-transformation, these processes correspond to the preliminary molecular motion preceding the macroscopic bending of the film. PMID:24736859

  2. Links between Plant and Rhizoplane Bacterial Communities in Grassland Soils, Characterized Using Molecular Techniques

    Microsoft Academic Search

    Naoise Nunan; Timothy J. Daniell; Brajesh K. Singh; Artemis Papert; James W. McNicol; James I. Prosser

    2005-01-01

    Molecular analysis of grassland rhizosphere soil has demonstrated complex and diverse bacterial commu- nities, with resultant difficulties in detecting links between plant and bacterial communities. These studies have, however, analyzed \\

  3. The use of molecular techniques for the diagnosis and epidemiologic study of sexually transmitted infections

    Microsoft Academic Search

    Carolyn M. Black; Stephen A. Morse

    2000-01-01

    Molecular diagnostic tests are more sensitive and, in many cases, more specific than conventional laboratory methods for the\\u000a detection of sexually transmitted infections. Here, we review recently developed molecular methods for the diagnosis and subtyping\\u000a of the most common sexually transmitted infections: infections caused by Chlamydia trachomatis, Neisseria gonorrhoeae, human papillomavirus, Trichomonas vaginalis, and the agents of genital ulcer disease

  4. 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.

  5. Recent advances in intracoronary imaging techniques: focus on optical coherence tomography.

    PubMed

    Kubo, Takashi; Akasaka, Takashi

    2008-11-01

    Optical coherence tomography (OCT) is a new imaging technology that utilizes advanced photonics and fiberoptics to obtain images and tissue characterization on a microscopic scale. The resolution of the current OCT system is 10-20 microm, which is approximately ten-times higher than that of intravascular ultrasound. Compared with conventional imaging modalities, OCT has a superior ability to evaluate vulnerable plaque features, such as plaque rupture, intracoronary thrombus, thin-capped fibroatheroma and macrophages within the fibrous caps. Furthermore, OCT can clearly visualize stent malapposition and tissue protrusion after stenting and neointimal hyperplasia at late follow-up. Although OCT is a specialized research tool, it might provide new insights into the diagnosis and treatment of coronary artery disease. PMID:19025345

  6. Improving the clinical assessment of consciousness with advances in electrophysiological and neuroimaging techniques.

    PubMed

    Gawryluk, Jodie R; D'Arcy, Ryan C N; Connolly, John F; Weaver, Donald F

    2010-01-01

    In clinical neurology, a comprehensive understanding of consciousness has been regarded as an abstract concept--best left to philosophers. However, times are changing and the need to clinically assess consciousness is increasingly becoming a real-world, practical challenge. Current methods for evaluating altered levels of consciousness are highly reliant on either behavioural measures or anatomical imaging. While these methods have some utility, estimates of misdiagnosis are worrisome (as high as 43%)--clearly this is a major clinical problem. The solution must involve objective, physiologically based measures that do not rely on behaviour. This paper reviews recent advances in physiologically based measures that enable better evaluation of consciousness states (coma, vegetative state, minimally conscious state, and locked in syndrome). Based on the evidence to-date, electroencephalographic and neuroimaging based assessments of consciousness provide valuable information for evaluation of residual function, formation of differential diagnoses, and estimation of prognosis. PMID:20113490

  7. 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.

  8. Clinical applications of imaging disease burden in multiple sclerosis: MRI and advanced imaging techniques.

    PubMed

    Riley, Claire; Azevedo, Christina; Bailey, Mary; Pelletier, Daniel

    2012-03-01

    This review will address the critical role of radiographic techniques in monitoring multiple sclerosis disease course and response to therapeutic interventions using conventional imaging. We propose an algorithm of obtaining a contrast-enhanced brain MRI 6 months after starting a disease-modifying therapy, and considering a gadolinium-enhancing lesion on that scan to indicate suboptimal response to therapy. New or enlarging T2 lesions should be followed on scans at 6-month intervals to assess for change, and the presence of one or more enhancing lesions on a 6- or 12-month scan, or two or more new or enlarging T2 lesions on a 12-month scan should prompt consideration of therapy change. New techniques such as PET imaging, magnetic resonance spectroscopy, magnetic resonance relaxometry, iron-sensitive imaging and perfusion MRI will also be overviewed, with their potential roles in monitoring disease course and activity. PMID:22364331

  9. 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.

  10. 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.

  11. Temperature and pressure measurement techniques for an advanced turbine test facility

    NASA Technical Reports Server (NTRS)

    Pollack, F. G.; Cochran, R. P.

    1980-01-01

    A high pressure, high-temperature turbine test facility constructed for use in turbine cooling research is described. Several recently developed temperature and pressure measuring techniques are used in this facility. The measurement techniques, their status, previous applications and some results are discussed. Noncontact surface temperature measurements are made by optical methods. Radiation pyrometry principles combined with photoelectric scanning are used for rotating components and infrared photography for stationary components. Contact (direct) temperature and pressure measurements on rotating components are expected to be handled with an 80 channel rotary data package which mounts on and rotates with the turbine shaft at speeds up to 17,500 rpm. The data channels are time-division multiplexed and converted to digital words in the data package. A rotary transformer couples power and digital data to and from the shaft.

  12. Temperature and pressure measurement techniques for an advanced turbine test facility

    NASA Technical Reports Server (NTRS)

    Pollack, F. G.; Cochran, R. P.

    1980-01-01

    A high pressure, high-temperature turbine test facility is being constructed at the NASA Lewis Research Center for use in turbine cooling research. Several recently developed temperature and pressure measuring techniques will be used in this facility. This paper describes these measurement techniques, their status, previous applications and some results. Noncontact surface temperature measurements will be made by optical methods. Radiation pyrometry principles combined with photoelectric scanning will be used for rotating components and infrared photography for stationary components. Contact (direct) temperature and pressure measurements on rotating components will be handled with an 80-channel rotary data package which mounts on and rotates with the turbine shaft at speeds up to 17,500 rpm. The data channels are time-division multiplexed and converted to digital words in the data package. A rotary transformer couples power and digital data to and from the shaft.

  13. Atmospheric effects in ERTS-1 data, and advanced information extraction techniques

    NASA Technical Reports Server (NTRS)

    Malila, W. A.; Walepka, R. F.

    1973-01-01

    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 data are presented. Empirical analyses of ERTS 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 data also is important. Problems occur when individual resolution elements contain two or more materials. Results from an initial application of ERIM techniques for estimating proportions of materials within individual elements are presented and discussed. Very accurate determination of surface areas of small lakes is achieved.

  14. Fat and epidermal cell suspension grafting: a new advanced one-step skin regeneration surgical technique

    PubMed Central

    2014-01-01

    Background Dystrophic skin scarring commonly occurs following skin cancer resections. In particular, the cosmetic outcome of skin graft reconstructions, following epidermoidal carcinoma removal, is generally poor due to wide marginal tumour excision, loss of subcutaneous tissues, and subsequent pigmented atrophic scarring of the graft coverage. Skin grafting sequelae need a three dimensional correction to restore either the epidermal layer or the dermal/subdermal volume and vascularization. Methods The surgeons combined CO2 laser ablation, subdermal lipofilling according to the Coleman’s technique and epidermal cell suspension autografting to correct wide depressed and dyschromic facial scar. The Authors applied this new technique on three nasal skin cancer resected patients: two of them actually need a longer follow-up, the third patient, a 48 yr old caucasian male, presented a skin grafting scar due to sclerodermiform basal cell carcinoma removal. This case is reported discussing pre-intra and post-operative records up to a complete twelve months follow-up. Results Records at six and twelve months follow-up after surgery demonstrate a fully integrated skin graft and a good restoration of the treated area, presenting the same texture and pigmentation of the adjacent untreated skin. Optimal, stable three-dimensional skin cosmetic restoration was obtained in a single stage surgical procedure. Conclusion Autologous non-cultured epidermal cell suspension transplantation on an epidermal laser ablated skin area, in combination with lipofilling subdermal reconstruction, appears to be an effective, simple and time-saving method to correct skin graft sequelae, in skin cancer patients. This new technique allows to restore a three-dimensional morphological structure of the treated area and to recover a natural appearance of the skin at the same time. The Authors believe that this technique can be safely used to treat any kind of dystrophic scarring. PMID:24565036

  15. Advances in the embedded-strain-gage technique with an application to contact problems

    Microsoft Academic Search

    M. Derenne; A. Bazergui

    1971-01-01

    Improvements in the embedded-strain-gage technique for the measurement of strains at internal points in models of machine\\u000a components are described. A New measurement module permits an experimental determination of the strain in models of epoxy\\u000a resin. By its construction, the centers of the rosettes may be accurately located in the model mold, before casting. A large\\u000a number of gages may

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

    Microsoft Academic Search

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

    2009-01-01

    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

  17. Recent advances in optical processing techniques using highly nonlinear bismuth oxide fiber

    Microsoft Academic Search

    Mable P. Fok; Chester Shu

    2008-01-01

    We report our recent studies on nonlinear processing of optical signals using a 35-cm highly nonlinear bismuth oxide fiber (Bi-NLF). Our findings are based on self-phase modulation, cross-phase modulation, and four-wave mixing in the Bi-NLF. We demonstrate applications of the nonlinear techniques in optical signal regeneration, tunable optical delay, stabilization of multiwavelength laser source, tunable optical pulse generation, microwave photonic

  18. Advanced computational techniques for incompressible/compressible fluid-structure interactions

    NASA Astrophysics Data System (ADS)

    Kumar, Vinod

    2005-07-01

    Fluid-Structure Interaction (FSI) problems are of great importance to many fields of engineering and pose tremendous challenges to numerical analyst. This thesis addresses some of the hurdles faced for both 2D and 3D real life time-dependent FSI problems with particular emphasis on parachute systems. The techniques developed here would help improve the design of parachutes and are of direct relevance to several other FSI problems. The fluid system is solved using the Deforming-Spatial-Domain/Stabilized Space-Time (DSD/SST) finite element formulation for the Navier-Stokes equations of incompressible and compressible flows. The structural dynamics solver is based on a total Lagrangian finite element formulation. Newton-Raphson method is employed to linearize the otherwise nonlinear system resulting from the fluid and structure formulations. The fluid and structural systems are solved in decoupled fashion at each nonlinear iteration. While rigorous coupling methods are desirable for FSI simulations, the decoupled solution techniques provide sufficient convergence in the time-dependent problems considered here. In this thesis, common problems in the FSI simulations of parachutes are discussed and possible remedies for a few of them are presented. Further, the effects of the porosity model on the aerodynamic forces of round parachutes are analyzed. Techniques for solving compressible FSI problems are also discussed. Subsequently, a better stabilization technique is proposed to efficiently capture and accurately predict the shocks in supersonic flows. The numerical examples simulated here require high performance computing. Therefore, numerical tools using distributed memory supercomputers with message passing interface (MPI) libraries were developed.

  19. Advanced computational techniques for incompressible\\/compressible fluid-structure interactions

    Microsoft Academic Search

    Vinod Kumar

    2005-01-01

    Fluid-Structure Interaction (FSI) problems are of great importance to many fields of engineering and pose tremendous challenges to numerical analyst. This thesis addresses some of the hurdles faced for both 2D and 3D real life time-dependent FSI problems with particular emphasis on parachute systems. The techniques developed here would help improve the design of parachutes and are of direct relevance

  20. Carbon dioxide capture and separation techniques for advanced power generation point sources

    Microsoft Academic Search

    H. W. Pennline; D. R. Luebke; B. I. Morsi; Y. J. Heintz; K. L. Jones; J. B. Ilconich

    2006-01-01

    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

  1. Reducing Undersampling Noise in PIC Codes Using Advanced Multiresolution Analysis Techniques

    NASA Astrophysics Data System (ADS)

    Won, Kirk; Afeyan, Bedros; Starck, Jean Luc

    2006-10-01

    We show results from the implemention of a number of new ideas stemming from the multiscale, multiresolution analysis arena where Poisson noise, or under-sampling noise, is adequately treated via a series of more and more geometrically sophisticated objects going from elementary 2D Haar wavelets, to isotropic undecimated wavelet transforms (in 2D), to biorthogonal Haar bases with multiscale nonlinear transforms that convert Poisson distributions to Gaussian ones where noise estimation (thresholding) is much easier, to curvelets, where orientation information (resolving coherent structures in phase space, detecting and respecting anisotropy) is vitally important. This suite of new techniques allows the accurate extraction of phase space densities with fidelity impossible to achieve with naive or trivial interpolation or smoothing techniques. We will demonstrate the relative strengths and detection capabilities of these techniques. The examples we treat are the Beam-Plasma Instability (BPI) and ponderomotively driven KEEN waves. These allow intricate phase space structures to coexist with chaos and turbulence. The former has a simple single mode linear limit which is unstable, but the latter gives rise to pure multimode nonlinear phenomena.

  2. Recent Advances of Portable Multi-Sensor Technique of Volcanic Plume Measurement

    NASA Astrophysics Data System (ADS)

    Shinohara, H.

    2005-12-01

    A technique has been developed to estimate chemical composition volcanic gases based on the measurement of volcanic plumes at distance from a source vent by the use of a portable multi-sensor system consisting a humidity sensor, an SO2 electrochemical sensor and a CO2 IR analyzer (Shinohara, 2005). Since volcanic plume is a mixture of the atmosphere and volcanic gases, the volcanic gas composition can be estimated by subtracting the atmospheric background from the plume data. This technique enabled us to estimate concentration ratios of major volcanic gas species (i.e., H2O, CO2 and SO2) without any complicated chemical analyses even for gases emitted from an inaccessible open vent. Since the portable multi-sensor system was light (~ 5 kg) and small enough to carry in a medium size backpack, we could apply this technique to measure volcanic plumes at summit of various volcanoes including those which require us a tough climbing, such as Villarrica volcano, Chile. We further improved the sensor system and the measurements techniques, including application of LI-840 IR H2O and CO2 analyzer, H2S electrochemical sensor and H2 semi-conductor sensor. Application of the new LI-840 analyzer enabled us to measure H2O concentration in the plume with similar response time with CO2 concentration. The H2S electrochemical sensor of Komyo Co. has a chemical filter to removed SO2 to achieve a low sensitivity (0.1%) to SO2, and we can measure a high SO2/H2S ratio up to 1000. The semi-conductor sensor can measure H2 concentration in the range from the background level in the atmosphere (~0.5 ppm) to ~50 ppm. Response of the H2 sensor is slower (90% response time = ~90 sec) than other sensors in particular in low concentration range, and the measurement is still semi-quantitative with errors up to ±50%. The H2/H2O ratios are quite variable in volcanic gases ranging from less than 10-5 up to 10-1, and the ratio is largely controlled by temperature and pressure condition of the internal equilibrium. In particular, we can calculate the equilibrium condition for the reaction (SO2 + 3H2 = 2H2O + H2S) based on the results of the plume measurements by the portable multi-sensor technique.

  3. Multiple time step molecular dynamics in the optimized isokinetic ensemble steered with the molecular theory of solvation: Accelerating with advanced extrapolation of effective solvation forces

    SciTech Connect

    Omelyan, Igor, E-mail: omelyan@ualberta.ca, E-mail: omelyan@icmp.lviv.ua [National Institute for Nanotechnology, 11421 Saskatchewan Drive, Edmonton, Alberta T6G 2M9 (Canada) [National Institute for Nanotechnology, 11421 Saskatchewan Drive, Edmonton, Alberta T6G 2M9 (Canada); Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 2G8 (Canada); Institute for Condensed Matter Physics, National Academy of Sciences of Ukraine, 1 Svientsitskii Street, Lviv 79011 (Ukraine); Kovalenko, Andriy, E-mail: andriy.kovalenko@nrc-cnrc.gc.ca [National Institute for Nanotechnology, 11421 Saskatchewan Drive, Edmonton, Alberta T6G 2M9 (Canada) [National Institute for Nanotechnology, 11421 Saskatchewan Drive, Edmonton, Alberta T6G 2M9 (Canada); Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 2G8 (Canada)

    2013-12-28

    We develop efficient handling of solvation forces in the multiscale method of multiple time step molecular dynamics (MTS-MD) of a biomolecule steered by the solvation free energy (effective solvation forces) obtained from the 3D-RISM-KH molecular theory of solvation (three-dimensional reference interaction site model complemented with the Kovalenko-Hirata closure approximation). To reduce the computational expenses, we calculate the effective solvation forces acting on the biomolecule by using advanced solvation force extrapolation (ASFE) at inner time steps while converging the 3D-RISM-KH integral equations only at large outer time steps. The idea of ASFE consists in developing a discrete non-Eckart rotational transformation of atomic coordinates that minimizes the distances between the atomic positions of the biomolecule at different time moments. The effective solvation forces for the biomolecule in a current conformation at an inner time step are then extrapolated in the transformed subspace of those at outer time steps by using a modified least square fit approach applied to a relatively small number of the best force-coordinate pairs. The latter are selected from an extended set collecting the effective solvation forces obtained from 3D-RISM-KH at outer time steps over a broad time interval. The MTS-MD integration with effective solvation forces obtained by converging 3D-RISM-KH at outer time steps and applying ASFE at inner time steps is stabilized by employing the optimized isokinetic Nosé-Hoover chain (OIN) ensemble. Compared to the previous extrapolation schemes used in combination with the Langevin thermostat, the ASFE approach substantially improves the accuracy of evaluation of effective solvation forces and in combination with the OIN thermostat enables a dramatic increase of outer time steps. We demonstrate on a fully flexible model of alanine dipeptide in aqueous solution that the MTS-MD/OIN/ASFE/3D-RISM-KH multiscale method of molecular dynamics steered by effective solvation forces allows huge outer time steps up to tens of picoseconds without affecting the equilibrium and conformational properties, and thus provides a 100- to 500-fold effective speedup in comparison to conventional MD with explicit solvent. With the statistical-mechanical 3D-RISM-KH account for effective solvation forces, the method provides efficient sampling of biomolecular processes with slow and/or rare solvation events such as conformational transitions of hydrated alanine dipeptide with the mean life times ranging from 30 ps up to 10 ns for “flip-flop” conformations, and is particularly beneficial for biomolecular systems with exchange and localization of solvent and ions, ligand binding, and molecular recognition.

  4. Recent advances in soybean transformation and their application to molecular breeding and genomic analysis

    PubMed Central

    Yamada, Tetsuya; Takagi, Kyoko; Ishimoto, Masao

    2012-01-01

    Herbicide-resistant transgenic soybean plants hold a leading market share in the USA and other countries, but soybean has been regarded as recalcitrant to transformation for many years. The cumulative and, at times, exponential advances in genetic manipulation have made possible further choices for soybean transformation. The most widely and routinely used transformation systems are cotyledonary node–Agrobacterium-mediated transformation and somatic embryo–particle-bombardment-mediated transformation. These ready systems enable us to improve seed qualities and agronomic characteristics by transgenic approaches. In addition, with the accumulation of soybean genomic resources, convenient or promising approaches will be requisite for the determination and use of gene function in soybean. In this article, we describe recent advances in and problems of soybean transformation, and survey the current transgenic approaches for applied and basic research in Japan. PMID:23136488

  5. Bursicon, the tanning hormone of insects: recent advances following the discovery of its molecular identity

    Microsoft Academic Search

    Hans-Willi Honegger; Elizabeth M. Dewey; John Ewer

    2008-01-01

    Bursicon was identified in 1965 as a peptide neurohormone that initiates the tanning of the insect cuticle immediately after\\u000a the shedding of the old one during the final stages of the molting process. Its molecular identity as an approximately 30 kDa\\u000a bioactive heterodimer consisting of two cystine knot proteins resisted elucidation for 43 years. The sequence of the two bursicon\\u000a subunits is

  6. Recent Advances And Future Prospective in Molecular Breeding of Cotton For Drought and Salinity Stress Tolerance

    Microsoft Academic Search

    Edward L. Lubbers; Peng W. Chee; Yehoshua Saranga; Andrew H. Paterson

    Fiber from cotton (Gossypium hirsutum and G. barbadense) is a major product in the world economy. It is a botanically unique plant as it is a perennial allotetraploid derived from\\u000a diploid Gossypium species, one of which does not produce lint, which is grown as an annual row crop. Cotton is an especially appropriate system\\u000a for research into the molecular basis

  7. 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

  8. Advanced NMR-based techniques for pore structure analysis of coal

    SciTech Connect

    Smith, D.M.

    1992-01-01

    One of the main problems in coal utilization is the inability to properly characterize its complex pore structure. Coals typically have micro/ultra-micro pores but they also exhibit meso and macroporosity. Conventional pore size techniques (adsorption/condensation, mercury porosimetry) are limited because of this broad pore size range, microporosity, reactive nature of coal, samples must be completely dried, and network/percolation effects. Small angle scattering is limited because it probes both open and closed pores. Although one would not expect any single technique to provide a satisfactory description of a coal's structure, it is apparent that better techniques are necessary. We believe that measurement of the NMR parameters of various gas phase and adsorbed phase NMR active probes can provide the resolution to this problem. We will investigate the dependence of the common NMR parameters such as chemical shifts and relaxation times of several different nuclei and compounds on the pore structure of model microporous solids, carbons, and coals. In particular, we will study the interaction between several small molecules and the pore surfaces in coals. These molecules have been selected for their chemical and physical properties. A special NMR probe will be constructed which will allow the concurrent measurement of NMR properties and adsorption uptake at a variety of temperatures. All samples will be subjected to a suite of conventional'' pore structure analyses. These include nitrogen adsorption at 77 K with BET analysis, CO[sub 2] and CH[sub 4] adsorption at 273 K with D-R (Dubinin-Radushkevich) analysis, helium pycnometry, and small angle X-ray scattering as well as gas diffusion measurements.

  9. 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

  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. Recent advances in developing molecular tools for targeted genome engineering of mammalian cells

    PubMed Central

    Lim, Kwang-il

    2015-01-01

    Various biological molecules naturally existing in diversified species including fungi, bacteria, and bacteriophage have functionalities for DNA binding and processing. The biological molecules have been recently actively engineered for use in customized genome editing of mammalian cells as the molecule-encoding DNA sequence information and the underlying mechanisms how the molecules work are unveiled. Excitingly, multiple novel methods based on the newly constructed artificial molecular tools have enabled modifications of specific endogenous genetic elements in the genome context at efficiencies that are much higher than that of the conventional homologous recombination based methods. This minireview introduces the most recently spotlighted molecular genome engineering tools with their key features and ongoing modifications for better performance. Such ongoing efforts have mainly focused on the removal of the inherent DNA sequence recognition rigidity from the original molecular platforms, the addition of newly tailored targeting functions into the engineered molecules, and the enhancement of their targeting specificity. Effective targeted genome engineering of mammalian cells will enable not only sophisticated genetic studies in the context of the genome, but also widely-applicable universal therapeutics based on the pinpointing and correction of the disease-causing genetic elements within the genome in the near future. [BMB Reports 2015; 48(1): 6-12] PMID:25104401

  12. 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).

  13. 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.

  14. Advances in kinetic isotope effect measurement techniques for enzyme mechanism study.

    PubMed

    Gu, Hong; Zhang, Shuming

    2013-01-01

    Kinetic isotope effects (KIEs) are a very powerful tool for investigating enzyme mechanisms. Precision of measurement is the most important factor for KIE determinations, especially for small heavy atom KIEs. Internal competition is commonly used to measure small KIEs on V/K. Several methods, including such as liquid scintillation counting, mass spectrometry, nuclear magnetic resonance spectroscopy and polarimetry have been used to determine KIEs. In this paper, which does not aspire to be an exhaustive review, we briefly review different experimental approaches for the measurement of KIEs on enzymatic reaction with an emphasis on newer techniques employing mass spectrometry and nuclear magnetic resonance spectrometry as well as some corresponding examples. PMID:23917115

  15. 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.

  16. Recent advances in latent print visualization techniques at the U.S. Secret Service

    NASA Astrophysics Data System (ADS)

    Ramotowski, Robert S.; Cantu, Antonio A.; Leben, Deborah A.; Joullie, Madeleine M.; Saunders, George C.

    1997-02-01

    The U.S. Secret Service has been doing and supporting research in several areas of fingerprint visualization. The following is discussed: (1) developing ninhydrin analogues for visualizing latent prints on porous surfaces such as paper (with Dr. Madeleine Joullie, University of Pennsylvania); (2) exploring reflective UV imaging techniques as a no-treatment-required method for visualizing latent prints; (3) optimizing 'gun bluing' methods for developing latent prints on metal surfaces (such as spent cartridges); (4) investigating aqueous metal deposition methods for visualizing latent prints on multiple types of surfaces; and (5) studying methods of transferring latent print residues onto membranes.

  17. Advances in analytical techniques: from biochemical assessment of nutritional status to the identification of controlling factors.

    PubMed

    Cynober, L

    2003-01-01

    Analytical techniques for the biochemical assessment of nutritional status have been the focus of continuing interest at ESPEN over the years. All the congress proceedings were scrutinized to prepare this review. A total of 274 abstracts were found to be relevant to the topic. Fifty-six of these were selected as especially representative of the topic and are referenced. Eighty-seven additional papers of special interest are mentioned in the text with the details necessary to find them easily in the Clin. Nutr. Supplement where they were published. Methods involving stable isotopes were not considered here because these are discussed elsewhere. PMID:14512051

  18. Advances in surgical techniques for resection of childhood cerebellopontine angle ependymomas are key to survival

    Microsoft Academic Search

    Robert A. Sanford; Thomas E. Merchant; Marike Zwienenberg-Lee; Larry E. Kun; Frederick A. Boop

    2009-01-01

    Background  Childhood cerebellopontine angle (CPA) ependymoma is an uncommon anatomical variant of posterior fossa ependymoma. In infants\\u000a and young children, the tumor often goes undetected until it causes hydrocephalus. As CPA ependymomas grow, they distort the\\u000a anatomy and encase cranial nerves and vessels, thereby making resection a formidable surgical challenge.\\u000a \\u000a \\u000a \\u000a Purpose  The purpose of this paper is to describe the surgical technique

  19. Soft X-Ray Microscopy and Spectroscopy at the Molecular Environmental Science Beamline at the Advanced Light Source

    SciTech Connect

    Bluhm, Hendrik; Andersson, Klas J.; Araki, Tohru; Benzerara, Karim; Brown, Gordon E.; Dynes, Jay J.; Ghosal, Sutapa; Gilles, Mary K.; Hansen, Hans C.; Hemminger, J. C.; Hitchcock, Adam P.; Ketteler, Guido; Kilcoyne, Arthur L.; Kneedler, Eric M.; Lawrence, John R.; Leppard, Gary G.; Majzlam, Juraj; Mun, B. S.; Myneni, Satish C.; Nilsson, Anders R.; Ogasawara, Hirohito; Ogletree, D. F.; Pecher, Klaus H.; Salmeron, Miquel B.; Shuh, David K.; Tonner, Brian; Tyliszczak, Tolek; Warwick, Tony; Yoon, T. H.

    2006-02-01

    We present examples of the application of synchrotron-based spectroscopies and microscopies to environmentally-relevant samples. The experiments were performed at the Molecular Environmental Science beamline (11.0.2) at the Advanced Light Source, Lawrence Berkeley National Laboratory. Examples range from the study of water monolayers on Pt(111) single crystal surfaces using X-ray emission spectroscopy and the examination of alkali halide solution/water vapor interfaces using ambient pressure photoemission spectroscopy, to the investigation of actinides, river-water biofilms, Al-containing colloids and mineral-bacteria suspensions using scanning transmission X-ray spectromicroscopy. The results of our experiments show that spectroscopy and microscopy in the soft X-ray energy range are excellent tools for the investigation of environmentally relevant samples under realistic conditions, i.e. with water or water vapor present at ambient temperature.

  20. 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.

  1. Pluripotent stem cell derivation and differentiation toward cardiac muscle: novel techniques and advances in patent literature.

    PubMed

    Quattrocelli, Mattia; Thorrez, Lieven; Sampaolesi, Maurilio

    2013-04-01

    Pluripotent stem cells hold unprecedented potential for regenerative medicine, disease modeling and drug screening. Embryonic stem cells (ESCs), standard model for pluripotency studies, have been recently flanked by induced pluripotent stem cells (iPSCs). iPSCs are obtained from somatic cells via epigenetic and transcriptional reprogramming, overcoming ESC-related ethical issues and enabling the possibility of donor-matching pluripotent cell lines. Since the European Court of Justice banned patents involving embryo disaggregation to generate human ESCs, iPSCs can now fuel the willingness of European companies to invest in treatments based on stem cells. Moreover, iPSCs share many unique features of ESCs, such as unlimited self-renewal potential and broad differentiation capability, even though iPSCs seem more susceptible to genomic instability and display epigenetic biases as compared to ESCs. Both ESCs and iPSCs have been intensely investigated for cardiomyocyte production and cardiac muscle regeneration, both in human and animal models. In vitro and in vivo studies are continuously expanding and refining this field via genetic manipulation and cell conditioning, trying to achieve standard and reproducible products, eligible for clinical and biopharmaceutical scopes. This review focuses on the recently growing body of patents, concerning technical advances in production, expansion and cardiac differentiation of ESCs and iPSCs. PMID:22974171

  2. Dynamic resource management technique with advance reservation over QoS-provisioned networks

    NASA Astrophysics Data System (ADS)

    Yi, DongHoon; Kim, JongWon

    2002-09-01

    Works on QoS-enabled IP networks have led to two distinct approaches: the integrated service (IntServ) and the differentiated service (DiffServ) architectures. To address the tradeoff between service guarantee and scalability, a resource manager (a.k.a. bandwidth broker: BB) can be employed to complement the IntServ/RSVP with the DiffServ in the pursuit of end-to-end QoS. One major component of the resource manager is a decision mechanism for resource allocation, which enables hosts to request per-flow, quantifiable resources along the end-to-end path and to obtain feedback regarding the acceptance. However, most of existing resource manager implementations are still adopting the decision mechanism that makes a decision on the immediate availability of resources, especially bandwidth. Considering the variations in the demand over the time, we can easily expect some level of inefficiency due to this in terms of resource utilization and management. Thus, we are investigating the methods to support the request scheduling and advance reservation for the dynamic resource management. We use a time slot manager to ensure that the committed resources never exceed a specified limit and to predict the unused (but reserved) bandwidth. Network simulations are conducted to evaluate the enhanced performance of the proposed mechanism (i.e., with respect to the acceptance rate, the resource utilization, and others).

  3. Have advances in extracorporeal removal techniques changed the indications for their use in poisonings?

    PubMed

    Garlich, Fiona M; Goldfarb, David S

    2011-05-01

    During the past 25 years, numerous changes have taken place in the use of hemodialysis as a therapeutic modality. Advances in technologies and a progression in our collective understanding of the pharmacokinetics of certain xenobiotics have resulted in alterations in the indications, effectiveness, and safety of hemodialysis. However, these changes have not necessarily been reflected in the current published data regarding treatment of intoxications. Reported clearance rates often reflect what was achievable in the 1970s and 1980s, and more recent reports are frequently lacking. Our goal in this review is to summarize the changes in hemodialysis and in other extracorporeal removal technologies and highlight the effects of these changes on the current indications for hemodialysis of the poisoned patient. Changes in dialysis performance that are reviewed in this article include the use of high-efficiency and high-flux dialysis membranes, improved hemodynamic stability because of ultrafiltration control, and the use of bicarbonate as a source of base. We review the indications for hemodialysis for removal of specific toxins, including vancomycin, methotrexate, carbamazepine, and valproic acid. PMID:21531323

  4. 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.

  5. Advances in fluorescence imaging techniques to detect oral cancer and its precursors

    PubMed Central

    Shin, Dongsuk; Vigneswaran, Nadarajah; Gillenwater, Ann; Richards-Kortum, Rebecca

    2010-01-01

    Oral cancer is a significant health problem in the USA and throughout the world. Most oral cancer patients are diagnosed at a late stage, when treatment is less successful and treatment-associated morbidity is more severe. A number of new diagnostic aids to conventional oral examination have recently been introduced to assist in the early detection of oral neoplasia. In particular, autofluorescence imaging has emerged as a promising adjunctive technique to improve early identification of oral premalignant lesions. Direct visual inspection of tissue autofluorescence has shown encouraging results in high-prevalence populations, but the technique requires subjective interpretation and depends on the visual recognition skills of the examiner. Capturing and analyzing digital fluorescence images can reduce subjectivity and potentially improve sensitivity of detection of precancerous changes. Recent studies of wide-field autofluorescence imaging in low-prevalence populations suggest that benign lesions such as inflammation may give rise to false-positive results. High-resolution fluorescence imaging is a new modality that can be used in conjunction with wide-field imaging to improve specificity by imaging subcellular detail of neoplastic tissues. The combination of wide-field and high-resolution fluorescence imaging systems with automated image analysis should be investigated to maximize overall diagnostic performance for early detection of oral neoplasia. PMID:20624126

  6. Advanced fiber optic fluorescence turn-on molecular sensor for highly selective detection of copper in water

    NASA Astrophysics Data System (ADS)

    Chiniforooshan, Yasser; Ma, Jianjun; Bock, Wojtek J.; Hao, Wenhui; Wang, Zhi Yuan

    2012-06-01

    In this article a novel advanced fiber-optic fluorescent sensor is demonstrated. The sensor is based on collection of the fluorescence from the sidewall of the multimode optical fiber which is partly de-cladded and covered by the sample under the test (SUT). The most part of the fluorescent intensity is carried by the leaky rays which are inaccessible in traditional evanescent-wave fluorescence fiber sensors. In the proposed structure, some part of a refracting power is collected in the de-cladded segment and used to excite the lower order lossless modes in cladded part by a sidewall mode mixer. In addition to the higher level of fluorescence collection, the architecture allows us to multiplex several different channels along one fiber, since we use only a small segment of the normal (not tapered) sidewall for each channel.A highly efficient fluorescence turn-on molecular probe is applied to this advanced fiber-optic structure, for sensitive and selective detection of Cu+2 in water. The fluorescence turn-on molecular probe is a mixture of a fluorophore polymer P1and M1 as a Cu receptor and a fluorescent quencher. The P1 is used as an indicator which generates the fluorescence centered at the wavelength of 650 nm and then, with a proper amount of M1 solution, the fluorescence is quenched up to 53% of its maximum intensity. The P1-M1 pair is broken by absorption of Cu with the M1 and the fluorescence is released again. This turn-on effect is used for detection of Cu with a low detection limit of 0.02689 g/ml.

  7. Investigation of the multiscale constitutive behavior of ferroelectric materials using advanced diffraction techniques

    NASA Astrophysics Data System (ADS)

    Rogan, Robert C.

    Ferroelectric ceramics are widely used in a diverse set of devices including sensors, actuators, and transducers. The technological importance of ferroelectrics originates from their large electromechanical coupling. Ferroelectric materials exhibit a complicated behavior in response to both electrical and mechanical loads which produce large internal stresses that eventually lead to failure. Efforts to model and predict the behavior of ferroelectrics have been hindered by the lack of suitable constitutive relations that accurately describe the electromechanical response of these materials. While many measurements have been conducted on the macroscopic response of single-crystals or polycrystals, multiaxial (and multiscale) data about the in situ internal strain and texture response of these materials is lacking; this information is critical to the development of accurate models, and diffraction techniques which directly measure internal crystal strains and material texture are aptly suited to supply it. A neutron diffraction technique was employed which allowed for the simultaneous measurement of material texture and lattice strains in directions parallel and transverse to an applied mechanical load. By comparing the behaviors of single-phase tetragonal, single-phase rhombohedral, and dual-phase morphotropic compositions, information concerning mechanics of average macroscopic behavior was inferred. In an effort to probe more of the multiaxial constitutive behavior, a high-energy X-ray diffraction technique was employed. Using transmission geometry and a 2-D image plate detector, 36 different directions of sample behavior were measured simultaneously. Polychromatic scanning X-ray microdiffraction was used to investigate the microscale three-dimensional strain tensor in single-crystals. One investigation yielded the first ever direct measurement of the tri-axial strain fields associated with single domain walls in ferroelectrics. The second investigation recorded the domain switching mechanisms activated to accommodate indentation-induced fracture stresses. Finally, 3-D XRD was used to probe the mesoscale constitutive behavior of single, embedded grains of BaTiO3 within a polycrystalline matrix. The experimental methods described in this thesis provide access to two-dimensional and three-dimensional multiaxial constitutive strain behavior in ferroelectrics for each of the microscopic , mesoscopic, and macroscopic length scales. Results from each of these length scales will provide critical data for models attempting to accurately describe the behavior of ferroelectric materials.

  8. A technique to achieve uniform stress distribution in compressive creep testing of advanced ceramics at high temperatures

    SciTech Connect

    Liu, K.C.; Stevens, C.O.; Brinkman, C.R. [Oak Ridge National Lab., TN (United States); Holshauser, N.E. [North Carolina Agricultural and Technical State Univ., Greensboro, NC (United States). Dept. of Mechanical Engineering

    1996-05-01

    A technique to achieve stable and uniform uniaxial compression is offered for creep testing of advanced ceramic materials at elevated temperatures, using an innovative self-aligning load-train assembly. Excellent load-train alignment is attributed to the inherent ability of a unique hydraulic universal coupler to maintain self-aligning. Details of key elements, design concept, and pricniples of operation of the self-aligning coupler are described. A method of alignment verification using a strain-gaged specimen is then discussed. Results of verification tests indicate that bending below 1.5% is routinely achievable usin the load-train system. A successful compression creep test is demonstrated using a dumbbell-shpaed Si nitride specimen tested at 1300 C for over 4000 h.

  9. Advanced Techniques for Real-Time Visualization of Data Intensive Missions

    SciTech Connect

    PLATZBECKER, MARK R.; ASHCRAFT, GARY W.; OWEN, TODD E.; STURGIS, BEVERLY R.

    2001-01-01

    Engineers at Sandia National Laboratories are combining entertainment industry software with traditional data collection techniques to create an interactive visualization tool. By replacing the usual flight simulator joystick with a telemetry data stream, experimental data is combined with existing three-dimensional (3D) engineering models. Users are immersed in their experiment, allowing interaction with and comprehension of complex data sets. Software tools are currently under development for post flight data visualization, and their usefulness and reusability have been demonstrated on numerous spaced-based programs within Sandia. However, data from remote sensors are subject to transmission errors that yield nonphysical behavior in real-time data visualization applications. We propose to investigate the applicability of real-time processing algorithms and estimation theories, such as Kalman filters, that have been successfully applied in other fields. Results will be integrated into existing postflight visualization tools for Proof-of-Concept validation and for potential integration of real-time applications.

  10. 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.

  11. 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

  12. Novel genotype-phenotype associations in human cancers enabled by advanced molecular platforms and computational analysis of whole slide images.

    PubMed

    Cooper, Lee A D; Kong, Jun; Gutman, David A; Dunn, William D; Nalisnik, Michael; Brat, Daniel J

    2015-04-01

    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

  13. Advanced transition metal phosphide materials from single-source molecular precursors

    NASA Astrophysics Data System (ADS)

    Colson, Adam Caleb

    In this thesis, the feasibility of employing organometallic single-source precursors in the preparation of advanced transition metal pnictide materials such as colloidal nanoparticles and films has been investigated. In particular, the ternary FeMnP phase was targeted as a model for preparing advanced heterobimetallic phosphide materials, and the iron-rich Fe3P phase was targeted due to its favorable ferromagnetic properties as well as the fact that the preparation of advanced Fe3P materials has been elusive by commonly used methods. Progress towards the synthesis of advanced Fe2--xMn xP nanomaterials and films was facilitated by the synthesis of the novel heterobimetallic complexes FeMn(CO)8(mu-PR1R 2) (R1 = H, R2 = H or R1 = H, R2 = Ph), which contain the relatively rare mu-PH2 and mu-PPhH functionalities. Iron rich Fe2--xMnxP nanoparticles were obtained by thermal decomposition of FeMn(CO)8(mu-PH 2) using solution-based synthetic methods, and empirical evidence suggested that oleic acid was responsible for manganese depletion. Films containing Fe, Mn, and P with the desired stoichiometric ratio of 1:1:1 were prepared using FeMn(CO)8(mu-PH2) in a simple low-pressure metal-organic chemical vapor deposition (MOCVD) apparatus. Although the elemental composition of the precursor was conserved in the deposited film material, spectroscopic evidence indicated that the films were not composed of pure-phase FeMnP, but were actually mixtures of crystalline FeMnP and amorphous FeP and Mn xOy. A new method for the preparation of phase-pure ferromagnetic Fe 3P films on quartz substrates has also been developed. This approach involved the thermal decomposition of the single-source precursors H 2Fe3(CO)9PR (R = tBu or Ph) at 400 °C. The films were deposited using a simple home-built MOCVD apparatus and were characterized using a variety of analytical methods. The films exhibited excellent phase purity, as evidenced by X-ray diffraction, X-ray photoelectron spectroscopy, and field-dependent magnetization measurements, the results of which were all in good agreement with measurements obtained from bulk Fe3P. As-deposited Fe3P films were found to be amorphous, and little or no magnetic hysteresis was observed in plots of magnetization versus applied field. Annealing the Fe3P films at 550 °C resulted in improved crystallinity as well as the observation of magnetic hysteresis.

  14. Molecular confocal laser endomicroscopy: A novel technique for in vivo cellular characterization of gastrointestinal lesions

    PubMed Central

    Karstensen, John Gásdal; Klausen, Pia Helene; Saftoiu, Adrian; Vilmann, Peter

    2014-01-01

    While flexible endoscopy is essential for macroscopic evaluation, confocal laser endomicroscopy (CLE) has recently emerged as an endoscopic method enabling visualization at a cellular level. Two systems are currently available, one based on miniprobes that can be inserted via a conventional endoscope or via a needle guided by endoscopic ultrasound. The second system has a confocal microscope integrated into the distal part of an endoscope. By adding molecular probes like fluorescein conjugated antibodies or fluorescent peptides to this procedure (either topically or systemically administered during on-going endoscopy), a novel world of molecular evaluation opens up. The method of molecular CLE could potentially be used for estimating the expression of important receptors in carcinomas, subsequently resulting in immediate individualization of treatment regimens, but also for improving the diagnostic accuracy of endoscopic procedures by identifying otherwise invisible mucosal lesions. Furthermore, studies have shown that fluorescein labelled drugs can be used to estimate the affinity of the drug to a target organ, which probably can be correlated to the efficacy of the drug. However, several of the studies in this research field have been conducted in animal facilities or in vitro, while only a limited number of trials have actually been carried out in vivo. Therefore, safety issues still needs further evaluations. This review will present an overview of the implications and pitfalls, as well as future challenges of molecular CLE in gastrointestinal diseases. PMID:24976717

  15. TMSmesh: A Robust Method for Molecular Surface Mesh Generation Using a Trace Technique

    E-print Network

    Lu, Benzhuo

    of Scientific/Engineering Computing, Institute of Computational Mathematics, Academy of Mathematics and Systems to a route to simulate electrostatic solvation of large-scale molecular systems. The binary version and numerical simulation of biomo- lecular systems raise new demands for qualified, stable, and efficient

  16. 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...

  17. The molecular dynamics of polymers in random nanometre confined spaces investigated by relaxational and scattering techniques

    NASA Astrophysics Data System (ADS)

    Schönhals, A.; Goering, H.; Brzezinka, K. W.; Schick, Ch

    2003-03-01

    Dielectric spectroscopy and temperature-modulated differential scanning calorimetry are employed to study the molecular dynamics of oligomeric poly(propylene glycol) (PPG) melts of different molecular weights confined to nanoporous glasses (pore sizes 2.5, 5.0, 7.5 and 20 nm). Moreover, the results obtained for the polymers are compared with those for the corresponding monomer. The experimental results are discussed in the framework of the interplay of confinement and adsorption effects. For large pore sizes (> 5 nm) a speeding up of the molecular dynamics is observed (the confinement effect), whereas for small pore sizes (< 5 nm) a slowing down of the segmental fluctuations is found (the adsorption effect). In addition, a minimal length scale for the glass transition of 1.6 nm is estimated for PPG confined in nanoporous glasses. This supports the idea that the molecular motions responsible for the glassy dynamics must be describable by a characteristic length scale. Polarized Raman scattering investigations are carried out to investigate the conformations of the macromolecules inside the pores. These experiments show that the confined polymer chains are locally stretched. This effect increases with decreasing pore size.

  18. 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...

  19. Advances in Immuno–Positron Emission Tomography: Antibodies for Molecular Imaging in Oncology

    PubMed Central

    Knowles, Scott M.; Wu, Anna M.

    2012-01-01

    Identification of cancer cell–surface biomarkers and advances in antibody engineering have led to a sharp increase in the development of therapeutic antibodies. These same advances have led to a new generation of radiolabeled antibodies and antibody fragments that can be used as cancer-specific imaging agents, allowing quantitative imaging of cell-surface protein expression in vivo. Immuno–positron emission tomography (immunoPET) imaging with intact antibodies has shown success clinically in diagnosing and staging cancer. Engineered antibody fragments, such as diabodies, minibodies, and single-chain Fv (scFv) –Fc, have been successfully employed for immunoPET imaging of cancer cell–surface biomarkers in preclinical models and are poised to bring same-day imaging into clinical development. ImmunoPET can potentially provide a noninvasive approach for obtaining target-specific information useful for titrating doses for radioimmunotherapy, for patient risk stratification and selection of targeted therapies, for evaluating response to therapy, and for predicting adverse effects, thus contributing to the ongoing development of personalized cancer treatment. PMID:22987087

  20. In vivo molecular imaging of chemokine receptor CXCR4 expression in patients with advanced multiple myeloma.

    PubMed

    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

    2015-04-01

    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 [(68)Ga]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). [(68)Ga]Pentixafor PET provided images with excellent specificity and contrast. In 10 of 14 patients with advanced MM [(68)Ga]Pentixafor PET/CT scans revealed MM manifestations, whereas only nine of 14 standard [(18)F]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 [(68)Ga]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

  1. 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

  2. Advanced electric-field scanning probe lithography on molecular resist using active cantilever

    NASA Astrophysics Data System (ADS)

    Kaestner, Marcus; Aydogan, Cemal; Lipowicz, Hubert-Seweryn; Ivanov, Tzvetan; Lenk, Steve; Ahmad, Ahmad; Angelov, Tihomir; Reum, Alexander; Ishchuk, Valentyn; Atanasov, Ivaylo; Krivoshapkina, Yana; Hofer, Manuel; Holz, Mathias; Rangelow, Ivo W.

    2015-03-01

    The routine "on demand" fabrication of features smaller than 10 nm opens up new possibilities for the realization of many novel nanoelectronic, NEMS, optical and bio-nanotechnology-based devices. Based on the thermally actuated, piezoresistive cantilever technology we have developed a first prototype of a scanning probe lithography (SPL) platform able to image, inspect, align and pattern features down to single digit nano regime. The direct, mask-less patterning of molecular resists using active scanning probes represents a promising path circumventing the problems in today's radiation-based lithography. Here, we present examples of practical applications of the previously published electric field based, current-controlled scanning probe lithography on molecular glass resist calixarene by using the developed tabletop SPL system. We demonstrate the application of a step-and-repeat scanning probe lithography scheme including optical as well as AFM based alignment and navigation. In addition, sequential read-write cycle patterning combining positive and negative tone lithography is shown. We are presenting patterning over larger areas (80 x 80 ?m) and feature the practical applicability of the lithographic processes.

  3. Advances in molecular biomarkers for gastric cancer: miRNAs as emerging novel cancer markers.

    PubMed

    Wu, Hua-Hsi; Lin, Wen-chang; Tsai, Kuo-Wang

    2014-01-01

    Carcinoma of the stomach is one of the most prevalent cancer types in the world. Although the incidence of gastric cancer is declining, the outcomes of gastric cancer patients remain dismal because of the lack of effective biomarkers to detect early gastric cancer. Modern biomedical research has explored many potential gastric cancer biomarker genes by utilising serum protein antigens, oncogenic genes or gene families through improving molecular biological technologies, such as microarray, RNA-Seq and the like. Recently, the small noncoding microRNAs (miRNAs) have been suggested to be critical regulators in the oncogenesis pathways and to serve as useful clinical biomarkers. This new class of biomarkers is emerging as a novel molecule for cancer diagnosis and prognosis, including gastric cancer. By translational suppression of target genes, miRNAs play a significant role in the gastric cancer cell physiology and tumour progression. There are potential implications of previously discovered gastric cancer molecular biomarkers and their expression modulations by respective miRNAs. Therefore, many miRNAs are found to play oncogenic roles or tumour-suppressing functions in human cancers. With the surprising stability of miRNAs in tissues, serum or other body fluids, miRNAs have emerged as a new type of cancer biomarker with immeasurable clinical potential. PMID:24456939

  4. Recent advances in understanding the molecular mechanism of chloroplast photorelocation movement.

    PubMed

    Kong, Sam-Geun; Wada, Masamitsu

    2014-04-01

    Plants are photosynthetic organisms that have evolved unique systems to adapt fluctuating environmental light conditions. In addition to well-known movement responses such as phototropism, stomatal opening, and nastic leaf movements, chloroplast photorelocation movement is one of the essential cellular responses to optimize photosynthetic ability and avoid photodamage. For these adaptations, chloroplasts accumulate at the areas of cells illuminated with low light (called accumulation response), while they scatter from the area illuminated with strong light (called avoidance response). Plant-specific photoreceptors (phototropin, phytochrome, and/or neochrome) mediate these dynamic directional movements in response to incident light position and intensity. Several factors involved in the mechanisms underlying the processes from light perception to actin-based movements have also been identified through molecular genetic approach. This review aims to discuss recent findings in the field relating to how chloroplasts move at molecular levels. This article is part of a Special Issue entitled: Dynamic and ultrastructure of bioenergetic membranes and their components. PMID:24333784

  5. Laser Capture Microdissection: Understanding the Techniques and Implications for Molecular Biology in Nursing Research Through Analysis of Breast Cancer Tumor Samples

    Microsoft Academic Search

    Karen L. Zanni; Garrett K. Chan

    2011-01-01

    Aim: The purpose of this paper is to review the techniques and implications of laser capture microdissection (LCM) to isolate tissue and DNA of interest using breast biopsy tissue as an example. Background: Tissues are a heterogeneous mix of different cell types, and molecular alterations are often specific to a single cell type. An accurate correlation of molecular and morphologic

  6. 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

  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. 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

  9. Advanced Techniques for Seismic Protection of Historical Buildings: Experimental and Numerical Approach

    SciTech Connect

    Mazzolani, Federico M. [Department of Structural Engineering, University of Naples 'Federico II' Piazzale Tecchio, 80, 80125, Naples (Italy)

    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.

  10. Magnetic and Structural characterization of Co nanowires using advanced electron microscopy techniques

    NASA Astrophysics Data System (ADS)

    Cantu-Valle, Jesus; Ruiz-Zepeda, Francisco; Sanchez, John Eder; Mendoza-Santoyo, Fernando; Ponnce, Arturo; UTSA Team

    2015-03-01

    We report the magnetic imaging and crystalline structure of high aspect ratio cobalt nanowires. Experimental results of magnetization reversal in cobalt nanowires are presented to illustrate the functionality of the in situ magnetization process through the manipulation of the objective lens. By making use of this applicability, we measure the magnetization and show experimental evidence of the magnetic flux distribution in polycrystalline cobalt nanowires using off-axis electron holography. The retrieved phase map can distinguishes the magnetic contribution from the crystalline contribution with high accuracy. To determine the size and orientation of the grains within the Co nanowires, PED-assisted orientation mapping was performed. Finally, the magnetic analysis performed at individual nanowires was correlated with the crystalline orientation map, obtained by PED-assisted crystal phase orientation mapping. The large shape anisotropy determines the mayor magnetization direction rather than the magneto-crystalline anisotropy in the studied nanowires. The combination of the two techniques allowed us to directly visualize the effects of the crystallographic texture on the magnetization of the nanowire. The authors would like to acknowledge Dr. B.J.H. Stadler for providing the samples and financial support from NSF PREM #DMR 0934218, CONACYT, #215762 and Department of Defense #64756-RT-REP.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Recent advances in the structural molecular biology of Ets transcription factors: interactions, interfaces and inhibition

    PubMed Central

    Cooper, Christopher D.O.; Newman, Joseph A.; Gileadi, Opher

    2014-01-01

    The Ets family of eukaryotic transcription factors is based around the conserved Ets DNA-binding domain. Although their DNA-binding selectivity is biochemically and structurally well characterized, structures of homodimeric and ternary complexes point to Ets domains functioning as versatile protein-interaction modules. In the present paper, we review the progress made over the last decade to elucidate the structural mechanisms involved in modulation of DNA binding and protein partner selection during dimerization. We see that Ets domains, although conserved around a core architecture, have evolved to utilize a variety of interaction surfaces and binding mechanisms, reflecting Ets domains as dynamic interfaces for both DNA and protein interaction. Furthermore, we discuss recent advances in drug development for inhibition of Ets factors, and the roles structural biology can play in their future. PMID:24450640

  17. 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

  18. 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

  19. Non-Hodgkin's B-cell lymphoma: advances in molecular strategies targeting drug resistance.

    PubMed

    Maxwell, Steve A; Mousavi-Fard, Seyed

    2013-09-01

    Non-Hodgkin's lymphoma (NHL) is a heterogeneous class of cancers displaying a diverse range of biological phenotypes, clinical behaviours and prognoses. Standard treatments for B-cell NHL are anthracycline-based combinatorial chemotherapy regimens composed of cyclophosphamide, doxorubicin, vincristine and prednisolone. Even though complete response rates of 40-50% with chemotherapy can be attained, a substantial proportion of patients relapse, resulting in 3-year overall survival rates of about 30%. Relapsed lymphomas are refractory to subsequent treatments with the initial chemotherapy regimen and can exhibit cross-resistance to a wide variety of anticancer drugs. The emergence of acquired chemoresistance thus poses a challenge in the clinic preventing the successful treatment and cure of disseminated B-cell lymphomas. Gene-expression analyses have increased our understanding of the molecular basis of chemotherapy resistance and identified rational targets for drug interventions to prevent and treat relapsed/refractory diffuse large B-cell lymphoma. Acquisition of drug resistance in lymphoma is in part driven by the inherent genetic heterogeneity and instability of the tumour cells. Due to the genetic heterogeneity of B-cell NHL, many different pathways leading to drug resistance have been identified. Successful treatment of chemoresistant NHL will thus require the rational design of combinatorial drugs targeting multiple pathways specific to different subtypes of B-cell NHL as well as the development of personalized approaches to address patient-to-patient genetic heterogeneity. This review highlights the new insights into the molecular basis of chemorefractory B-cell NHL that are facilitating the rational design of novel strategies to overcome drug resistance. PMID:23986223

  20. 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

  1. Molecular Detection of Cucumber Mosaic Virus and Other RNA Viruses Based on New Techniques

    Microsoft Academic Search

    Jishuang Chen

    \\u000a Plant diseases caused by viruses and related pathogenic agents bring about substantial losses in agricultural and horticultural\\u000a crops. And the study of plant viruses has contributed quite a lot to the agricultural progress and basic understanding of\\u000a plant development as a molecular standard. For example, based on a virus’s diagnosis, the omission of plant viruses from potato\\u000a and many vegetative

  2. Approaches for the analysis of low molecular weight compounds with laser desorption/ionization techniques and mass spectrometry.

    PubMed

    Bergman, Nina; Shevchenko, Denys; Bergquist, Jonas

    2014-01-01

    This review summarizes various approaches for the analysis of low molecular weight (LMW) compounds by different laser desorption/ionization mass spectrometry techniques (LDI-MS). It is common to use an agent to assist the ionization, and small molecules are normally difficult to analyze by, e.g., matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) using the common matrices available today, because the latter are generally small organic compounds themselves. This often results in severe suppression of analyte peaks, or interference of the matrix and analyte signals in the low mass region. However, intrinsic properties of several LDI techniques such as high sensitivity, low sample consumption, high tolerance towards salts and solid particles, and rapid analysis have stimulated scientists to develop methods to circumvent matrix-related issues in the analysis of LMW molecules. Recent developments within this field as well as historical considerations and future prospects are presented in this review. PMID:24322735

  3. Coupling of gas chromatography and molecular beam/mass spectrometry analytical techniques: Application to flame structure study

    NASA Astrophysics Data System (ADS)

    Turbiez, A.; Devynck, P.; Desgroux, P.; Pauwels, J. F.

    1999-06-01

    A new experimental technique coupling both molecular beam and mass spectrometry (MBMS) and gas chromatography (GC) is developed to improve the analysis of low pressure reactive systems using a probe sampling procedure. The sensitivity of gas chromatography is greatly enhanced by using a compression procedure for the samples before injection into the chromatograph, and its selectivity allows one to separate isomers and to study very complex mixtures. By contrast MBMS is well suited to atoms and radical species detection. Moreover, the temperature dependence of the fragmentation pattern of heavy hydrocarbons during MBMS ionization is pointed out and it can be resolved alternatively by GC calibration. The complementarity of these two analytical techniques is demonstrated in the case of low pressure natural gas flames study.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Update in salivary gland cytopathology: Recent molecular advances and diagnostic applications.

    PubMed

    Pusztaszeri, Marc P; Faquin, William C

    2015-07-01

    Salivary gland tumors (SGT) are notorious for their extraordinary diversity and for the morphological overlap that exists between many of these entities. Fine-needle aspiration biopsy (FNAB) has a well-established role in the evaluation of patients with a salivary gland lesion, helping to guide clinical management. However, salivary gland FNAB has several limitations and does not allow for a specific diagnosis in some cases. For these reasons, salivary gland FNAB is considered one of the most challenging areas in cytopathology. Over the last decade, new salivary gland entities have been recognized, enlarging SGT diversity and complexity even more. In addition, a subset of SGT, including common entities such as pleomorphic adenoma and uncommon new entities such as mammary analog secretory carcinoma, have been characterized cytogenetically by the presence of specific translocations. The molecular consequences of these translocations and their potential prognostic and therapeutic values are not yet well characterized. However, these translocations and their resulting fusion oncogenes and oncoproteins can be used as diagnostic clues in salivary gland FNAB material in order to overcome the limitations of cytomorphological evaluation alone. In this review, we focus on SGTs currently known to harbor translocations and fusion genes, including uncommon and recently recognized entities, and discuss their potential application to salivary gland FNAB. PMID:25613003

  9. 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

  10. 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

  11. Recent advances in the understanding of brown spider venoms: From the biology of spiders to the molecular mechanisms of toxins.

    PubMed

    Gremski, Luiza Helena; Trevisan-Silva, Dilza; Ferrer, Valéria Pereira; Matsubara, Fernando Hitomi; Meissner, Gabriel Otto; Wille, Ana Carolina Martins; Vuitika, Larissa; Dias-Lopes, Camila; Ullah, Anwar; de Moraes, Fábio Rogério; Chávez-Olórtegui, Carlos; Barbaro, Katia Cristina; Murakami, Mario Tyago; Arni, Raghuvir Krishnaswamy; Senff-Ribeiro, Andrea; Chaim, Olga Meiri; Veiga, Silvio Sanches

    2014-06-01

    The Loxosceles genus spiders (the brown spiders) are encountered in all the continents, and the clinical manifestations following spider bites include skin necrosis with gravitational lesion spreading and occasional systemic manifestations, such as intravascular hemolysis, thrombocytopenia and acute renal failure. Brown spider venoms are complex mixtures of toxins especially enriched in three molecular families: the phospholipases D, astacin-like metalloproteases and Inhibitor Cystine Knot (ICK) peptides. Other toxins with low level of expression also present in the venom include the serine proteases, serine protease inhibitors, hyaluronidases, allergen factors and translationally controlled tumor protein (TCTP). The mechanisms by which the Loxosceles venoms act and exert their noxious effects are not fully understood. Except for the brown spider venom phospholipase D, which causes dermonecrosis, hemolysis, thrombocytopenia and renal failure, the pathological activities of the other venom toxins remain unclear. The objective of the present review is to provide insights into the brown spider venoms and loxoscelism based on recent results. These insights include the biology of brown spiders, the clinical features of loxoscelism and the diagnosis and therapy of brown spider bites. Regarding the brown spider venom, this review includes a description of the novel toxins revealed by molecular biology and proteomics techniques, the data regarding three-dimensional toxin structures, and the mechanism of action of these molecules. Finally, the biotechnological applications of the venom components, especially for those toxins reported as recombinant molecules, and the challenges for future study are discussed. PMID:24631373

  12. Advances in molecular genetic studies of attention deficit hyperactivity disorder in China

    PubMed Central

    GAO, Qian; LIU, Lu; QIAN, Qiujin; WANG, Yufeng

    2014-01-01

    Summary Attention deficit hyperactivity disorder (ADHD) is a common psychiatric condition in children worldwide that typically includes a combination of symptoms of inattention and hyperactivity/impulsivity. Genetic factors are believed to be important in the development and course of ADHD so many candidate genes studies and genome-wide association studies (GWAS) have been conducted in search of the genetic mechanisms that cause or influence the condition. This review provides an overview of gene association and pharmacogenetic studies of ADHD from mainland China and elsewhere that use Han Chinese samples. To date, studies from China and elsewhere remain inconclusive so future studies need to consider alternative analytic techniques and test new biological hypotheses about the relationship of neurotransmission and neurodevelopment to the onset and course of this disabling condition. PMID:25317006

  13. 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

  14. Continuous distribution model for the investigation of complex molecular architectures near interfaces with scattering techniques

    PubMed Central

    Shekhar, Prabhanshu; Nanda, Hirsh; Lösche, Mathias; Heinrich, Frank

    2011-01-01

    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). PMID:22207767

  15. Investigation of molecular and elemental species dynamics in NTO, TNT, and ANTA using femtosecond LIBS technique

    NASA Astrophysics Data System (ADS)

    Nageswara Rao, E.; Sunku, Sreedhar; Tewari, Surya P.; Manoj Kumar, G.; Venugopal Rao, S.

    2013-05-01

    We present our initial experimental results from the LIBS studies of pyrazole, 1-nitropyrazole, 3-nitropyrazole, 3,4- dinitropyrazole and 1-methyl- 3,4,5 trinitro pyrazole recorded with femtosecond pulses and performed in argon atmosphere. CN molecular bands in three different spectral regions of 357 nm-360 nm, 384 nm-389 nm and 414 nm -423 nm, C2 swan bands near 460 nm-475 nm, 510 nm- 520 nm and 550 nm-565 nm were observed. The C peak at 247.82 nm, H peak at 656.2 nm have also been observed along with several peaks of O and N. CN/C2, CN/C, C2/C and C2/N ratios were measured from the average of 25 spectra obtained in argon. The effect of number of nitro groups on the atomic and molecular emission has been evaluated. A gate delay of 100 ns and a gate width of 800 ns were used for collecting the spectra.

  16. 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).

  17. 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.

  18. Utilising Recent Advancements in Techniques for the Analysis of Incomplete Multivariate Data to Improve the Data Quality Management of Current Academic Research

    Microsoft Academic Search

    David J. Fogarty; John Blake

    2002-01-01

    This paper discusses the importance of managing data quality in academic research in its relation to satisfying the customer. This focus is on the data completeness objectivedimension of data quality in relation to recent advancements which have been made in the development of methods for analysing incomplete multivariate data. An overview and comparison of the traditional techniques with the recent

  19. MR enterography in Crohn's disease: current consensus on optimal imaging technique and future advances from the SAR Crohn's disease-focused panel.

    PubMed

    Grand, David J; Guglielmo, Flavius F; Al-Hawary, Mahmoud M

    2015-06-01

    MR enterography is a powerful tool for the non-invasive evaluation of patients with Crohn's disease (CD) without ionizing radiation. The following paper describes the current consensus on optimal imaging technique, interpretation, and future advances from the Society of Abdominal Radiology CD-focused panel. PMID:25666967

  20. Phospholipid Membrane Protection by Sugar Molecules during Dehydration—Insights into Molecular Mechanisms Using Scattering Techniques

    PubMed Central

    Garvey, Christopher J.; Lenné, Thomas; Koster, Karen L.; Kent, Ben; Bryant, Gary

    2013-01-01

    Scattering techniques have played a key role in our understanding of the structure and function of phospholipid membranes. These techniques have been applied widely to study how different molecules (e.g., cholesterol) can affect phospholipid membrane structure. However, there has been much less attention paid to the effects of molecules that remain in the aqueous phase. One important example is the role played by small solutes, particularly sugars, in protecting phospholipid membranes during drying or slow freezing. In this paper, we present new results and a general methodology, which illustrate how contrast variation small angle neutron scattering (SANS) and synchrotron-based X-ray scattering (small angle (SAXS) and wide angle (WAXS)) can be used to quantitatively understand the interactions between solutes and phospholipids. Specifically, we show the assignment of lipid phases with synchrotron SAXS and explain how SANS reveals the exclusion of sugars from the aqueous region in the particular example of hexagonal II phases formed by phospholipids. PMID:23584028