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Sample records for capillary-alveolar macromolecular leakage

  1. Increased cardiac index due to terbutaline treatment aggravates capillary-alveolar macromolecular leakage in oleic acid lung injury in dogs

    OpenAIRE

    Briot, Raphael; Bayat, Sam; Anglade, Daniel; Martiel, Jean-Louis; Grimbert, Francis

    2009-01-01

    Introduction We assessed the in vivo effects of terbutaline, a beta2-agonist assumed to reduce microvascular permeability in acute lung injury. Methods We used a recently developed broncho-alveolar lavage (BAL) technique to repeatedly measure (every 15 min. for 4 hours) the time-course of capillary-alveolar leakage of a macromolecule (fluorescein-labeled dextran) in 19 oleic acid (OA) lung injured dogs. BAL was performed in a closed lung sampling site, using a bronchoscope fitted with an infl...

  2. Curcumin suppresses gastric NF-κB activation and macromolecular leakage in Helicobacter pylori-infected rats

    Institute of Scientific and Technical Information of China (English)

    Kawiya; Sintara; Duangporn; Thong-Ngam; Suthiluk; Patumraj; Naruemon; Klaikeaw; Tanittha; Chatsuwan

    2010-01-01

    AIM:To investigate whether curcumin could attenuate nuclear factor(NF)-κB p65 expression and macromolecular leakage in the gastric mucosa of Helicobacter pylori(H.pylori)-infected rats.METHODS:Twenty-five male Sprague-Dawley rats were equally divided into five groups:control rats(Control),control rats supplemented with 600 mg/kg curcumin,H.pylori-infected rats(Hp),H.pylori-infected rats supplemented with 200 mg/kg curcumin(Hp + curIn H.pylori-infected groups,rats were inoculated with H.pylori suspension twi...

  3. Spectroscopic Approach to Capillary-Alveolar Membrane Damage Induced Acute Lung Injury

    Directory of Open Access Journals (Sweden)

    Jing Wang

    1999-01-01

    Full Text Available BACKGROUND: Acute (or adult respiratory distress syndrome (ARDS is often associated with a high mortality rate in the critical care population. The term acute lung injury (ALI, a primitive phase of ARDS, was introduced by the European and American consensus groups to provide early diagnoses of ARDS. The pathophysiological characterization of ALI/ARDS – an increased pulmonary capillary-alveolar membrane barrier permeability – is generally not included in current intensive care unit diagnosis criteria.

  4. Effects of babassu nut oil on ischemia/reperfusion-induced leukocyte adhesion and macromolecular leakage in the microcirculation: Observation in the hamster cheek pouch

    Directory of Open Access Journals (Sweden)

    Barbosa Maria do

    2012-11-01

    Full Text Available Abstract Background The babassu palm tree is native to Brazil and is most densely distributed in the Cocais region of the state of Maranhão, in northeastern Brazil. In addition to the industrial use of refined babassu oil, the milk, the unrefined oil and the nuts in natura are used by families from several communities of African descendants as one of the principal sources of food energy. The objective of this study was to evaluate the effects of babassu oil on microvascular permeability and leukocyte-endothelial interactions induced by ischemia/reperfusion using the hamster cheek pouch microcirculation as experimental model. Methods Twice a day for 14 days, male hamsters received unrefined babassu oil (0.02 ml/dose [BO-2 group], 0.06 ml/dose [BO-6 group], 0.18 ml/dose [BO-18 group] or mineral oil (0.18 ml/dose [MO group]. Observations were made in the cheek pouch and macromolecular permeability increase induced by ischemia/reperfusion (I/R or topical application of histamine, as well as leukocyte-endothelial interaction after I/R were evaluated. Results The mean value of I/R-induced microvascular leakage, determined during reperfusion, was significantly lower in the BO-6 and BO-18 groups than in the MO one (P Conclusions Our findings suggest that unrefined babassu oil reduced microvascular leakage and protected against histamine-induced effects in postcapillary venules and highlights that these almost unexploited nut and its oil might be secure sources of food energy.

  5. Macromolecular crystallization in microgravity

    Energy Technology Data Exchange (ETDEWEB)

    Snell, Edward H [Biophysics Group, NASA Marshall Space Flight Center, Code XD42, Huntsville, AL 35812 (United States); Helliwell, John R [Department of Chemistry, The University of Manchester, Manchester, M13 9PL (United Kingdom)

    2005-04-01

    Density difference fluid flows and sedimentation of growing crystals are greatly reduced when crystallization takes place in a reduced gravity environment. In the case of macromolecular crystallography a crystal of a biological macromolecule is used for diffraction experiments (x-ray or neutron) so as to determine the three-dimensional structure of the macromolecule. The better the internal order of the crystal then the greater the molecular structure detail that can be extracted. It is this structural information that enables an understanding of how the molecule functions. This knowledge is changing the biological and chemical sciences, with major potential in understanding disease pathologies. In this review, we examine the use of microgravity as an environment to grow macromolecular crystals. We describe the crystallization procedures used on the ground, how the resulting crystals are studied and the knowledge obtained from those crystals. We address the features desired in an ordered crystal and the techniques used to evaluate those features in detail. We then introduce the microgravity environment, the techniques to access that environment and the theory and evidence behind the use of microgravity for crystallization experiments. We describe how ground-based laboratory techniques have been adapted to microgravity flights and look at some of the methods used to analyse the resulting data. Several case studies illustrate the physical crystal quality improvements and the macromolecular structural advances. Finally, limitations and alternatives to microgravity and future directions for this research are covered. Macromolecular structural crystallography in general is a remarkable field where physics, biology, chemistry and mathematics meet to enable insight to the fundamentals of life. As the reader will see, there is a great deal of physics involved when the microgravity environment is applied to crystallization, some of it known, and undoubtedly much yet to

  6. Teaching macromolecular modeling.

    OpenAIRE

    Harvey, S C; Tan, R K

    1992-01-01

    Training newcomers to the field of macromolecular modeling is as difficult as is training beginners in x-ray crystallography, nuclear magnetic resonance, or other methods in structural biology. In one or two lectures, the most that can be conveyed is a general sense of the relationship between modeling and other structural methods. If a full semester is available, then students can be taught how molecular structures are built, manipulated, refined, and analyzed on a computer. Here we describe...

  7. Microgravity and Macromolecular Crystallography

    Science.gov (United States)

    Kundrot, Craig E.; Judge, Russell A.; Pusey, Marc L.; Snell, Edward H.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    Macromolecular crystal growth has been seen as an ideal experiment to make use of the reduced acceleration environment provided by an orbiting spacecraft. The experiments are small, simply operated and have a high potential scientific and economic impact. In this review we examine the theoretical reasons why microgravity should be a beneficial environment for crystal growth and survey the history of experiments on the Space Shuttle Orbiter, on unmanned spacecraft, and on the Mir space station. Finally we outline the direction for optimizing the future use of orbiting platforms.

  8. Axioms for Information Leakage

    OpenAIRE

    Alvim, Mário S.; Chatzikokolakis, Konstantinos; McIver, Annabelle; Morgan, Carroll; Palamidessi, Catuscia; Smith, Geoffrey

    2016-01-01

    Quantitative information flow aims to assess and control the leakage of sensitive information by computer systems. A key insight in this area is that no single leakage measure is appropriate in all operational scenarios; as a result, many leakage measures have been proposed, with many different properties. To clarify this complex situation, this paper studies information leakage axiomatically, showing important dependencies among different axioms. It also establishes a completeness result abo...

  9. Macromolecular architectures for organic photovoltaics.

    Science.gov (United States)

    Popere, Bhooshan C; Della Pelle, Andrea M; Poe, Ambata; Thayumanavan, S

    2012-03-28

    Research in the field of organic photovoltaics has gained considerable momentum in the last two decades owing to the need for developing low-cost and efficient energy harvesting systems. Elegant molecular architectures have been designed, synthesized and employed as active materials for photovoltaic devices thereby leading to a better molecular structure-device property relationship understanding. In this perspective, we outline new macromolecular scaffolds that have been designed within the purview of each of the three fundamental processes involving light harvesting, charge separation and charge transport.

  10. Emergent Property in Macromolecular Motion

    Institute of Scientific and Technical Information of China (English)

    吴嘉麟

    2003-01-01

    In this paper, the model of inverse cascade fractal super-blocks along one direction (in the positive or negative) in the 3-dimensional space is developed to describe the self-similar motion in macromolecular system. Microscopically the cohesive and dispersed states of the motion blocks are co-existent states with vastly different probability of occurrence.Experimental results and theoretical analysis show that the microscopic cohesive state energy and dispersed state energy of each motion block are respectively equal to the macroscopic glassy state energy kT8 and molten state energy kTm of the system. This singularity unveils topologically the nonintegrability, mathematically the anholonomy, and macroscopically the emergent property. This singularity also reveals that the glass, viscoelastic and melt states are three distinct emergent properties of macromolecular motion from a macroscopic viewpoint. The fractal concept of excluded volume is introduced to depict the random motion at various scales in the system. The Hausdorff dimensions of the excluded volune and the motion blocks are both found equal to 3/2.

  11. Data Mining of Macromolecular Structures.

    Science.gov (United States)

    van Beusekom, Bart; Perrakis, Anastassis; Joosten, Robbie P

    2016-01-01

    The use of macromolecular structures is widespread for a variety of applications, from teaching protein structure principles all the way to ligand optimization in drug development. Applying data mining techniques on these experimentally determined structures requires a highly uniform, standardized structural data source. The Protein Data Bank (PDB) has evolved over the years toward becoming the standard resource for macromolecular structures. However, the process selecting the data most suitable for specific applications is still very much based on personal preferences and understanding of the experimental techniques used to obtain these models. In this chapter, we will first explain the challenges with data standardization, annotation, and uniformity in the PDB entries determined by X-ray crystallography. We then discuss the specific effect that crystallographic data quality and model optimization methods have on structural models and how validation tools can be used to make informed choices. We also discuss specific advantages of using the PDB_REDO databank as a resource for structural data. Finally, we will provide guidelines on how to select the most suitable protein structure models for detailed analysis and how to select a set of structure models suitable for data mining.

  12. Liver-targeting macromolecular MRI contrast agents

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Macromolecular ligands with liver-targeting group (pyridoxamine, PM) PHEA-DTPA-PM and PAEA-DTPA-PM were prepared by the incorporation of different amount of diethylenetriaminepentaacetic acid monopyridoxamine group (DTPA-PM) into poly-a, b-[N-(2-hydroxyethyl)-L- aspartamide] (PHEA) and poly-a, b-[N-(2-aminoethyl)-L-aspartamide] (PAEA). The macromolecular ligands thus obtained were further complexed with gadolinium chloride to give macromolecular MRI contrast agents with different Gd(Ⅲ) contents. These macromolecular ligands and their gadolinium complexes were characterized by 1H NMR, IR, UV and elementary analysis. Relaxivity studies showed that these polyaspartamide gadolinium complexes possess higher relaxation effectiveness than that of the clinically used Gd-DTPA. Magnetic resonance imaging of the liver in rats and experimental data of biodistribution in mice indicate that these macromolecular MRI contrast agents containing pyridoxamine exhibit liver-targeting property.

  13. Land-use Leakage

    Energy Technology Data Exchange (ETDEWEB)

    Calvin, Katherine V.; Edmonds, James A.; Clarke, Leon E.; Bond-Lamberty, Benjamin; Kim, Son H.; Wise, Marshall A.; Thomson, Allison M.; Kyle, G. Page

    2009-12-01

    Leakage occurs whenever actions to mitigate greenhouse gas emissions in one part of the world unleash countervailing forces elsewhere in the world so that reductions in global emissions are less than emissions mitigation in the mitigating region. While many researchers have examined the concept of industrial leakage, land-use policies can also result in leakage. We show that land-use leakage is potentially as large as or larger than industrial leakage. We identify two potential land-use leakage drivers, land-use policies and bioenergy. We distinguish between these two pathways and run numerical experiments for each. We also show that the land-use policy environment exerts a powerful influence on leakage and that under some policy designs leakage can be negative. International “offsets” are a potential mechanism to communicate emissions mitigation beyond the borders of emissions mitigating regions, but in a stabilization regime designed to limit radiative forcing to 3.7 2/m2, this also implies greater emissions mitigation commitments on the part of mitigating regions.

  14. Macromolecular crystallography research at Trombay

    International Nuclear Information System (INIS)

    Neutron diffraction studies of hydrogen positions in small molecules of biological interest at Trombay have provided valuable information that has been used in protein and enzyme structure model-building and in developing hydrogen bond potential functions. The new R-5 reactor is expected to provide higher neutron fluxes and also make possible small-angle neutron scattering studies of large biomolecules and bio-aggregates. In the last few years infrastructure facilities have also been established for macromolecular x-ray crystallography research. Meanwhile, the refinement of carbonic hydrases and lyysozyme structures have been carried out and interesting results obtained on protein dynamics and structure-function relationships. Some interesting presynaptic toxin phospholipases have also taken up for study. (author)

  15. Model for Electromagnetic Information Leakage

    Directory of Open Access Journals (Sweden)

    Mao Jian

    2013-09-01

    Full Text Available Electromagnetic leakage will happen in working information equipments; it could lead to information leakage. In order to discover the nature of information in electromagnetic leakage, this paper combined electromagnetic theory with information theory as an innovative research method. It outlines a systematic model of electromagnetic information leakage, which theoretically describes the process of information leakage, intercept and reproduction based on electromagnetic radiation, and analyzes amount of leakage information with formulas.  

  16. Colon anastomotic leakage

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian; Achiam, Michael Patrick; Rosenberg, Jacob

    2014-01-01

    PURPOSE: Colon anastomotic leakage remains a serious and common surgical complication. Animal models are valuable to determine the pathophysiological mechanisms and to evaluate possible methods of prevention. The aim of this study was to develop an optimal model of clinical colon anastomotic...... group [0.49 N ± 0.15] (p = 0.091). CONCLUSIONS: This mouse model closely mimics clinical colon anastomotic leakage in humans. The model is of high clinical relevance, since anastomotic leakage has a similar cause, incidence and manifestations in humans....

  17. Assessing Agulhas leakage

    OpenAIRE

    Van Sebille, E.

    2009-01-01

    Agulhas leakage, the water that flows from the Indian Ocean to the Atlantic Ocean, plays an important role in the circulation of the Atlantic Ocean. The magnitude of this flux of warm and saline Indian Ocean water into the much colder and fresher Atlantic Ocean can be related to the strength of the Atlantic meridional overturning circulation, both in numerical ocean models and in paleoceanographic records. However, estimating the magnitude of this Agulhas leakage is not easy. The Agulhas regi...

  18. Energy transfer in macromolecular arrays

    Science.gov (United States)

    Andrews, David L.; Jenkins, Robert D.

    2003-11-01

    Macromolecular systems comprised of many light-sensitive centres (the photosynthetic unit, dendrimers, and other highly symmetric multichromophore arrays) are important structures offering challenges to theoreticians and synthetic chemists alike. Here we outline novel photophysical interactions predicted and observed in such arrays. Using the tools of molecular quantum electrodynamics (QED) we present quantum amplitudes for a variety of higher-order resonance energy transfer (RET) schemes associated with well-known nonlinear optical effects such as two- and three-photon absorption. The initial analysis is extended to account for situations where the participant donor species are identical and exist in a highly symmetric environment, leading to the possible formation of excitons. It emerges from the QED theory that such excitons are closely associated with the higher-order RET processes. General results are interpreted by analyzing particular molecular architectures which offer interesting features such as rate enhancement or limitation and exciton pathway quenching. Applications in the areas of photosynthesis, molecular logic gates and low-intensity fluorescence energy transfer are predicted.

  19. Fractal Dimensions of Macromolecular Structures

    Science.gov (United States)

    Todoroff, Nickolay; Kunze, Jens; Schreuder, Herman; Hessler, Gerhard; Baringhaus, Karl-Heinz; Schneider, Gisbert

    2014-01-01

    Quantifying the properties of macromolecules is a prerequisite for understanding their roles in biochemical processes. One of the less-explored geometric features of macromolecules is molecular surface irregularity, or ‘roughness’, which can be measured in terms of fractal dimension (D). In this study, we demonstrate that surface roughness correlates with ligand binding potential. We quantified the surface roughnesses of biological macromolecules in a large-scale survey that revealed D values between 2.0 and 2.4. The results of our study imply that surface patches involved in molecular interactions, such as ligand-binding pockets and protein-protein interfaces, exhibit greater local fluctuations in their fractal dimensions than ‘inert’ surface areas. We expect approximately 22 % of a protein’s surface outside of the crystallographically known ligand binding sites to be ligandable. These findings provide a fresh perspective on macromolecular structure and have considerable implications for drug design as well as chemical and systems biology. PMID:26213587

  20. Zero leakage sealings

    Science.gov (United States)

    Kotesovec, Bernhard; Steinrück, Herbert

    2010-11-01

    The piston rod of a reciprocating compressor is sealed with elastic cylindrical sealing elements. Across the sealings the pressure drops from the operating pressure to the ambient pressure. The lubrication gap between the elastic sealing and reciprocating piston rod is studied with the aim to find conditions of a leakage free sealing. The flow in the lubrication gap and the elastic deformation of the sealing are determined simultaneously. The net-flow during one cycle of the reciprocating piston rod is calculated. It turns out that maintaining zero leakage is very sensible. Indeed the outbound flow during out-stroke has to be equal the inbound flow during the in-stroke. By prescribing a special shape of the undeformed sealing zero leakage can be attained - at least theoretically for certain operating conditions. It turns out that temperature dependent material data and a model for cavitation is necessary. The model, its numerical implementation and results will be discussed.

  1. Assessing Agulhas leakage

    NARCIS (Netherlands)

    van Sebille, E.

    2009-01-01

    Agulhas leakage, the water that flows from the Indian Ocean to the Atlantic Ocean, plays an important role in the circulation of the Atlantic Ocean. The magnitude of this flux of warm and saline Indian Ocean water into the much colder and fresher Atlantic Ocean can be related to the strength of the

  2. New pharmaceutical applications for macromolecular binders.

    Science.gov (United States)

    Bertrand, Nicolas; Gauthier, Marc A; Bouvet, Céline; Moreau, Pierre; Petitjean, Anne; Leroux, Jean-Christophe; Leblond, Jeanne

    2011-10-30

    Macromolecular binders consist of polymers, dendrimers, and oligomers with binding properties for endogenous or exogenous substrates. This field, at the frontier of host/guest chemistry and pharmacology, has met a renewed interest in the past decade due to the clinical success of several sequestrants, like sevelamer hydrochloride (Renagel®) or sugammadex (Bridion®). In many instances, multivalent binding by the macromolecular drugs can modify the properties of the substrate, and may prevent it from reaching its site of action and/or trigger a biological response. From small (e.g., ions) to larger substrates (e.g., bacteria and cells), this review presents the state-of-the-art of macromolecular binders and provides detailed illustrative examples of recent developments bearing much promise for future pharmaceutical applications. PMID:21571017

  3. Macromolecular mimicry of nucleic acid and protein

    DEFF Research Database (Denmark)

    Nautrup Pedersen, Gitte; Nyborg, Jens; Clark, Brian F

    1999-01-01

    of the concept of macromolecular mimicry. Macromolecular mimicry has further been proposed among initiation and release factors, thereby adding a new element to the description of protein synthesis in bacteria. Such mimicry has also been observed in other biological processes such as autoimmunity, DNA repair......Although proteins and nucleic acids consist of different chemical components, proteins can mimic structures and possibly also functions of nucleic acids. Recently, structural mimicry was observed between two elongation factors in bacterial protein biosynthesis leading to the introduction...

  4. Leakage behind casing

    OpenAIRE

    Khandka, Rupak Kumar

    2007-01-01

    Achieving zonal isolation by cementing annulus space between casing and well bore is an important job in many oil wells. Gas leakage in the annulus has been recognised as a major completion problem in the oil well. A successful cement job results in complete zonal isolation on a permanent basis. To achieve these goals, various factors such as well security, casing centralization, effective mud removal, and gas migration must be considered in the design. The design of the cement must be such t...

  5. Determining the architectures of macromolecular assemblies

    NARCIS (Netherlands)

    Alber, Frank; Dokudovskaya, Svetlana; Veenhoff, Liesbeth M.; Zhang, Wenzhu; Kipper, Julia; Devos, Damien; Suprapto, Adisetyantari; Karni-Schmidt, Orit; Williams, Rosemary; Chait, Brian T.; Rout, Michael P.; Sali, Andrej

    2007-01-01

    To understand the workings of a living cell, we need to know the architectures of its macromolecular assemblies. Here we show how proteomic data can be used to determine such structures. The process involves the collection of sufficient and diverse high-quality data, translation of these data into s

  6. Leakage resilient password systems

    CERN Document Server

    Li, Yingjiu; Deng, Robert H

    2015-01-01

    This book investigates tradeoff between security and usability in designing leakage resilient password systems (LRP) and introduces two practical LRP systems named Cover Pad and ShadowKey. It demonstrates that existing LRP systems are subject to both brute force attacks and statistical attacks and that these attacks cannot be effectively mitigated without sacrificing the usability of LRP systems. Quantitative analysis proves that a secure LRP system in practical settings imposes a considerable amount of cognitive workload unless certain secure channels are involved. The book introduces a secur

  7. SRAM standby leakage decoupling analysis for different leakage reduction techniques

    Institute of Scientific and Technical Information of China (English)

    Dong Qing; Lin Yinyin

    2013-01-01

    SRAM standby leakage reduction plays a pivotal role in minimizing the power consumption of application processors.Generally,four kinds of techniques are often utilized for SRAM standby leakage reduction:Vdd lowering (VDDL),Vss rising (VSSR),BL floating (BLF) and reversing body bias (RBB).In this paper,we comprehensively analyze and compare the reduction effects of these techniques on different kinds of leakage.It is disclosed that the performance of these techniques depends on the leakage composition of the SRAM cell and temperature.This has been verified on a 65 nm SRAM test macro.

  8. Growth and dissolution of macromolecular Markov chains

    CERN Document Server

    Gaspard, Pierre

    2016-01-01

    The kinetics and thermodynamics of free living copolymerization are studied for processes with rates depending on k monomeric units of the macromolecular chain behind the unit that is attached or detached. In this case, the sequence of monomeric units in the growing copolymer is a kth-order Markov chain. In the regime of steady growth, the statistical properties of the sequence are determined analytically in terms of the attachment and detachment rates. In this way, the mean growth velocity as well as the thermodynamic entropy production and the sequence disorder can be calculated systematically. These different properties are also investigated in the regime of depolymerization where the macromolecular chain is dissolved by the surrounding solution. In this regime, the entropy production is shown to satisfy Landauer's principle.

  9. Dextran: A promising macromolecular drug carrier

    Directory of Open Access Journals (Sweden)

    Dhaneshwar Suneela

    2006-01-01

    Full Text Available Over the past three decades intensive efforts have been made to design novel systems able to deliver the drug more effectively to the target site. The ongoing intense search for novel and innovative drug delivery systems is predominantly a consequence of the well-established fact that the conventional dosage forms are not sufficiently effective in conveying the drug compound to its site of action and once in the target area, in releasing the active agent over a desired period of time. The potential use of macromolecular prodrugs as a means of achieving targeted drug delivery has attracted considerable interest in recent years. Macromolecules such as antibodies, lipoproteins, lectins, proteins, polypeptides, polysaccharides, natural as well as synthetic polymers offer potential applicabilities as high molecular weight carriers for various therapeutically active compounds. Dextrans serve as one of the most promising macromolecular carrier candidates for a wide variety of therapeutic agents due to their excellent physico-chemical properties and physiological acceptance. The present contribution attempts to review various features of the dextran carrier like its source, structural and physico-chemical characteristics, pharmacokinetic fate and its applications as macromolecular carrier with special emphasis on dextran prodrugs.

  10. Smoothing techniques for macromolecular global optimization

    Energy Technology Data Exchange (ETDEWEB)

    More, J.J.; Wu, Zhijun

    1995-09-01

    We study global optimization problems that arise in macromolecular modeling, and the solution of these problems via continuation and smoothing. Our results unify and extend the theory associated with the use of the Gaussian transform for smoothing. We show that the, Gaussian transform can be viewed as a special case of a generalized transform and that these generalized transforms share many of the properties of the Gaussian transform. We also show that the smoothing behavior of the generalized transform can be studied in terms of the Fourier transform and that these results indicate that the Gaussian transform has superior smoothing properties.

  11. Automated macromolecular crystal detection system and method

    Science.gov (United States)

    Christian, Allen T.; Segelke, Brent; Rupp, Bernard; Toppani, Dominique

    2007-06-05

    An automated macromolecular method and system for detecting crystals in two-dimensional images, such as light microscopy images obtained from an array of crystallization screens. Edges are detected from the images by identifying local maxima of a phase congruency-based function associated with each image. The detected edges are segmented into discrete line segments, which are subsequently geometrically evaluated with respect to each other to identify any crystal-like qualities such as, for example, parallel lines, facing each other, similarity in length, and relative proximity. And from the evaluation a determination is made as to whether crystals are present in each image.

  12. Celebrating macromolecular crystallography: A personal perspective

    Directory of Open Access Journals (Sweden)

    Abad-Zapatero, Celerino

    2015-04-01

    Full Text Available The twentieth century has seen an enormous advance in the knowledge of the atomic structures that surround us. The discovery of the first crystal structures of simple inorganic salts by the Braggs in 1914, using the diffraction of X-rays by crystals, provided the critical elements to unveil the atomic structure of matter. Subsequent developments in the field leading to macromolecular crystallography are presented with a personal perspective, related to the cultural milieu of Spain in the late 1950’s. The journey of discovery of the author, as he developed professionally, is interwoven with the expansion of macromolecular crystallography from the first proteins (myoglobin, hemoglobin to the ‘coming of age’ of the field in 1971 and the discoveries that followed, culminating in the determination of the structure of the ribosomes at the turn of the century. A perspective is presented exploring the future of the field and also a reflection about the future generations of Spanish scientists.El siglo XX ha sido testigo del increíble avance que ha experimentado el conocimiento de la estructura atómica de la materia que nos rodea. El descubrimiento de las primeras estructuras atómicas de sales inorgánicas por los Bragg en 1914, empleando difracción de rayos X con cristales, proporcionó los elementos clave para alcanzar tal conocimiento. Posteriores desarrollos en este campo, que condujeron a la cristalografía macromolecular, se presentan aquí desde una perspectiva personal, relacionada con el contexto cultural de la España de la década de los 50. La experiencia del descubrimiento científico, durante mi desarrollo profesional, se integra en el desarrollo de la cristalografía macromolecular, desde las primeras proteínas (míoglobina y hemoglobina, hasta su madurez en 1971 que, con los posteriores descubrimientos, culmina con la determinación del la estructura del ribosoma. Asimismo, se explora el futuro de esta disciplina y se

  13. Duct Leakage Repeatability Testing

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-08-01

    The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques for duct leakage using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards. The three duct leak measurement methods assessed in this report are the two duct pressurization methods that are commonly used by many practitioners and the DeltaQ technique. These are methods B, C and A, respectively of the ASTM E1554 standard. Although it would be useful to evaluate other duct leak test methods, this study focused on those test methods that are commonly used and are required in various test standards, such as BPI (2010), RESNET (2014), ASHRAE 62.2 (2013), California Title 24 (CEC 2012), DOE Weatherization and many other energy efficiency programs.

  14. Multifamily Envelope Leakage Model

    Energy Technology Data Exchange (ETDEWEB)

    Faakye, Omari [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Griffiths, Dianne [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2015-05-08

    “The cost for blower testing is high, because it is labor intensive, and it may disrupt occupants in multiple units. This high cost and disruption deter program participants, and dissuade them from pursuing energy improvements that would trigger air leakage testing, such as improvements to the building envelope.” This statement found in a 2012 report by Heschong Mahone Group for several California interests emphasizes the importance of reducing the cost and complexity of blower testing in multifamily buildings. Energy efficiency opportunities are being bypassed. The cost of single blower testing is on the order of $300. The cost for guarded blower door testing—the more appropriate test for assessing energy savings opportunities—could easily be six times that, and that’s only if you have the equipment and simultaneous access to multiple apartments. Thus, the proper test is simply not performed. This research seeks to provide an algorithm for predicting the guarded blower door test result based upon a single, total blower door test.

  15. Duct Leakage Repeatability Testing

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-01-01

    Duct leakage often needs to be measured to demonstrate compliance with requirements or to determine energy or Indoor Air Quality (IAQ) impacts. Testing is often done using standards such as ASTM E1554 (ASTM 2013) or California Title 24 (California Energy Commission 2013 & 2013b), but there are several choices of methods available within the accepted standards. Determining which method to use or not use requires an evaluation of those methods in the context of the particular needs. Three factors that are important considerations are the cost of the measurement, the accuracy of the measurement and the repeatability of the measurement. The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards.

  16. The role of macromolecular stability in desiccation tolerance.

    NARCIS (Netherlands)

    Wolkers, W.

    1998-01-01

    The work presented in this thesis concerns a study on the molecular interactions that play a role in the macromolecular stability of desiccation-tolerant higher plant organs. Fourier transform infrared microspectroscopy was used as the main experimental technique to assess macromolecular structures

  17. Panorama of ancient metazoan macromolecular complexes.

    Science.gov (United States)

    Wan, Cuihong; Borgeson, Blake; Phanse, Sadhna; Tu, Fan; Drew, Kevin; Clark, Greg; Xiong, Xuejian; Kagan, Olga; Kwan, Julian; Bezginov, Alexandr; Chessman, Kyle; Pal, Swati; Cromar, Graham; Papoulas, Ophelia; Ni, Zuyao; Boutz, Daniel R; Stoilova, Snejana; Havugimana, Pierre C; Guo, Xinghua; Malty, Ramy H; Sarov, Mihail; Greenblatt, Jack; Babu, Mohan; Derry, W Brent; Tillier, Elisabeth R; Wallingford, John B; Parkinson, John; Marcotte, Edward M; Emili, Andrew

    2015-09-17

    Macromolecular complexes are essential to conserved biological processes, but their prevalence across animals is unclear. By combining extensive biochemical fractionation with quantitative mass spectrometry, here we directly examined the composition of soluble multiprotein complexes among diverse metazoan models. Using an integrative approach, we generated a draft conservation map consisting of more than one million putative high-confidence co-complex interactions for species with fully sequenced genomes that encompasses functional modules present broadly across all extant animals. Clustering reveals a spectrum of conservation, ranging from ancient eukaryotic assemblies that have probably served cellular housekeeping roles for at least one billion years, ancestral complexes that have accrued contemporary components, and rarer metazoan innovations linked to multicellularity. We validated these projections by independent co-fractionation experiments in evolutionarily distant species, affinity purification and functional analyses. The comprehensiveness, centrality and modularity of these reconstructed interactomes reflect their fundamental mechanistic importance and adaptive value to animal cell systems. PMID:26344197

  18. Macromolecular diffractive imaging using imperfect crystals

    Science.gov (United States)

    Ayyer, Kartik; Yefanov, Oleksandr M.; Oberthür, Dominik; Roy-Chowdhury, Shatabdi; Galli, Lorenzo; Mariani, Valerio; Basu, Shibom; Coe, Jesse; Conrad, Chelsie E.; Fromme, Raimund; Schaffer, Alexander; Dörner, Katerina; James, Daniel; Kupitz, Christopher; Metz, Markus; Nelson, Garrett; Xavier, Paulraj Lourdu; Beyerlein, Kenneth R.; Schmidt, Marius; Sarrou, Iosifina; Spence, John C. H.; Weierstall, Uwe; White, Thomas A.; Yang, Jay-How; Zhao, Yun; Liang, Mengning; Aquila, Andrew; Hunter, Mark S.; Robinson, Joseph S.; Koglin, Jason E.; Boutet, Sébastien; Fromme, Petra; Barty, Anton; Chapman, Henry N.

    2016-02-01

    The three-dimensional structures of macromolecules and their complexes are mainly elucidated by X-ray protein crystallography. A major limitation of this method is access to high-quality crystals, which is necessary to ensure X-ray diffraction extends to sufficiently large scattering angles and hence yields information of sufficiently high resolution with which to solve the crystal structure. The observation that crystals with reduced unit-cell volumes and tighter macromolecular packing often produce higher-resolution Bragg peaks suggests that crystallographic resolution for some macromolecules may be limited not by their heterogeneity, but by a deviation of strict positional ordering of the crystalline lattice. Such displacements of molecules from the ideal lattice give rise to a continuous diffraction pattern that is equal to the incoherent sum of diffraction from rigid individual molecular complexes aligned along several discrete crystallographic orientations and that, consequently, contains more information than Bragg peaks alone. Although such continuous diffraction patterns have long been observed—and are of interest as a source of information about the dynamics of proteins—they have not been used for structure determination. Here we show for crystals of the integral membrane protein complex photosystem II that lattice disorder increases the information content and the resolution of the diffraction pattern well beyond the 4.5-ångström limit of measurable Bragg peaks, which allows us to phase the pattern directly. Using the molecular envelope conventionally determined at 4.5 ångströms as a constraint, we obtain a static image of the photosystem II dimer at a resolution of 3.5 ångströms. This result shows that continuous diffraction can be used to overcome what have long been supposed to be the resolution limits of macromolecular crystallography, using a method that exploits commonly encountered imperfect crystals and enables model-free phasing.

  19. Phylogenetic Diversity in the Macromolecular Composition of Microalgae

    Science.gov (United States)

    Finkel, Zoe V.; Follows, Mick J.; Liefer, Justin D.; Brown, Chris M.; Benner, Ina; Irwin, Andrew J.

    2016-01-01

    The elemental stoichiometry of microalgae reflects their underlying macromolecular composition and influences competitive interactions among species and their role in the food web and biogeochemistry. Here we provide a new estimate of the macromolecular composition of microalgae using a hierarchical Bayesian analysis of data compiled from the literature. The median macromolecular composition of nutrient-sufficient exponentially growing microalgae is 32.2% protein, 17.3% lipid, 15.0% carbohydrate, 17.3% ash, 5.7% RNA, 1.1% chlorophyll-a and 1.0% DNA as percent dry weight. Our analysis identifies significant phylogenetic differences in macromolecular composition undetected by previous studies due to small sample sizes and the large inherent variability in macromolecular pools. The phylogenetic differences in macromolecular composition lead to variations in carbon-to-nitrogen ratios that are consistent with independent observations. These phylogenetic differences in macromolecular and elemental composition reflect adaptations in cellular architecture and biochemistry; specifically in the cell wall, the light harvesting apparatus, and storage pools. PMID:27228080

  20. Functional Sub-states by High-pressure Macromolecular Crystallography.

    Science.gov (United States)

    Dhaussy, Anne-Claire; Girard, Eric

    2015-01-01

    At the molecular level, high-pressure perturbation is of particular interest for biological studies as it allows trapping conformational substates. Moreover, within the context of high-pressure adaptation of deep-sea organisms, it allows to decipher the molecular determinants of piezophily. To provide an accurate description of structural changes produced by pressure in a macromolecular system, developments have been made to adapt macromolecular crystallography to high-pressure studies. The present chapter is an overview of results obtained so far using high-pressure macromolecular techniques, from nucleic acids to virus capsid through monomeric as well as multimeric proteins.

  1. Sequential recovery of macromolecular components of the nucleolus.

    Science.gov (United States)

    Bai, Baoyan; Laiho, Marikki

    2015-01-01

    The nucleolus is involved in a number of cellular processes of importance to cell physiology and pathology, including cell stress responses and malignancies. Studies of macromolecular composition of the nucleolus depend critically on the efficient extraction and accurate quantification of all macromolecular components (e.g., DNA, RNA, and protein). We have developed a TRIzol-based method that efficiently and simultaneously isolates these three macromolecular constituents from the same sample of purified nucleoli. The recovered and solubilized protein can be accurately quantified by the bicinchoninic acid assay and assessed by polyacrylamide gel electrophoresis or by mass spectrometry. We have successfully applied this approach to extract and quantify the responses of all three macromolecular components in nucleoli after drug treatments of HeLa cells, and conducted RNA-Seq analysis of the nucleolar RNA.

  2. Air-Leakage Control Manual.

    Energy Technology Data Exchange (ETDEWEB)

    Maloney, Jim; Washington State Energy Office; United States. Bonneville Power Administration.

    1991-05-01

    This manual is for builders and designers who are interested in building energy-efficient homes. The purpose of the manual is to provide the how and why'' of controlling air leakage by means of a system called the Simple Caulk and Seal'' (SIMPLE{center dot}CS) system. This manual provides an overview of the purpose and contents of the manual; It discusses the forces that affect air leakage in homes and the benefits of controlling air leakage. Also discussed are two earlier approaches for controlling air leakage and the problems with these approaches. It describes the SIMPLE-{center dot}CS system. It outlines the standard components of the building envelope that require sealing and provides guidelines for sealing them. It outlines a step-by-step procedure for analyzing and planning the sealing effort. The procedure includes (1) identifying areas to be sealed, (2) determining the most effective and convenient stage of construction in which to do the sealing, and (3) designating the appropriate crew member or trade to be responsible for the sealing.

  3. Air-leakage control manual

    Energy Technology Data Exchange (ETDEWEB)

    Maloney, J. [Washington State Energy Office, Olympia, WA (United States)

    1991-05-01

    This manual is for builders and designers who are interested in building energy-efficient homes. The purpose of the manual is to provide the ``how and why`` of controlling air leakage by means of a system called the ``Simple Caulk and Seal`` (SIMPLE{center_dot}CS) system. This manual provides an overview of the purpose and contents of the manual; It discusses the forces that affect air leakage in homes and the benefits of controlling air leakage. Also discussed are two earlier approaches for controlling air leakage and the problems with these approaches. It describes the SIMPLE-{center_dot}CS system. It outlines the standard components of the building envelope that require sealing and provides guidelines for sealing them. It outlines a step-by-step procedure for analyzing and planning the sealing effort. The procedure includes (1) identifying areas to be sealed, (2) determining the most effective and convenient stage of construction in which to do the sealing, and (3) designating the appropriate crew member or trade to be responsible for the sealing.

  4. A Novel Algorithm for Macromolecular Epitope Matching

    Directory of Open Access Journals (Sweden)

    Stanislav Jakuschev

    2009-03-01

    Full Text Available Many macromolecules, namely proteins, show functional substructures or epitopes defined by characteristic spatial arrangements of groups of specific atoms or residues. The identification of such substructures in a set of macromolecular 3D-structures solves an important problem in molecular biology as it allows the assignment of functions to molecular moieties and thus opens the possibility of a mechanistic understanding of molecular function. We have devised an algorithm that models a functional epitope formed by a group of atoms or residues as set of points in cartesian space with associated functional properties. The algorithm searches for similar epitopes in a database of structures by an efficient multistage comparison of distance sets in the epitope and in the structures from the database. The search results in a list of optimal matches and corresponding optimal superpositions of query epitope and matching epitopes from the database. The algorithm is discussed against the background of related approaches, and it is successfully tested in three application scenarios: global match of two homologous proteins, search for an epitope on a homologous protein, and finding matching epitopes in a protein database.

  5. An upper limit for macromolecular crowding effects

    Directory of Open Access Journals (Sweden)

    Miklos Andrew C

    2011-05-01

    Full Text Available Abstract Background Solutions containing high macromolecule concentrations are predicted to affect a number of protein properties compared to those properties in dilute solution. In cells, these macromolecular crowders have a large range of sizes and can occupy 30% or more of the available volume. We chose to study the stability and ps-ns internal dynamics of a globular protein whose radius is ~2 nm when crowded by a synthetic microgel composed of poly(N-isopropylacrylamide-co-acrylic acid with particle radii of ~300 nm. Results Our studies revealed no change in protein rotational or ps-ns backbone dynamics and only mild (~0.5 kcal/mol at 37°C, pH 5.4 stabilization at a volume occupancy of 70%, which approaches the occupancy of closely packing spheres. The lack of change in rotational dynamics indicates the absence of strong crowder-protein interactions. Conclusions Our observations are explained by the large size discrepancy between the protein and crowders and by the internal structure of the microgels, which provide interstitial spaces and internal pores where the protein can exist in a dilute solution-like environment. In summary, microgels that interact weakly with proteins do not strongly influence protein dynamics or stability because these large microgels constitute an upper size limit on crowding effects.

  6. Macromolecular Crystal Growth by Means of Microfluidics

    Science.gov (United States)

    vanderWoerd, Mark; Ferree, Darren; Spearing, Scott; Monaco, Lisa; Molho, Josh; Spaid, Michael; Brasseur, Mike; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    We have performed a feasibility study in which we show that chip-based, microfluidic (LabChip(TM)) technology is suitable for protein crystal growth. This technology allows for accurate and reliable dispensing and mixing of very small volumes while minimizing bubble formation in the crystallization mixture. The amount of (protein) solution remaining after completion of an experiment is minimal, which makes this technique efficient and attractive for use with proteins, which are difficult or expensive to obtain. The nature of LabChip(TM) technology renders it highly amenable to automation. Protein crystals obtained in our initial feasibility studies were of excellent quality as determined by X-ray diffraction. Subsequent to the feasibility study, we designed and produced the first LabChip(TM) device specifically for protein crystallization in batch mode. It can reliably dispense and mix from a range of solution constituents into two independent growth wells. We are currently testing this design to prove its efficacy for protein crystallization optimization experiments. In the near future we will expand our design to incorporate up to 10 growth wells per LabChip(TM) device. Upon completion, additional crystallization techniques such as vapor diffusion and liquid-liquid diffusion will be accommodated. Macromolecular crystallization using microfluidic technology is envisioned as a fully automated system, which will use the 'tele-science' concept of remote operation and will be developed into a research facility for the International Space Station as well as on the ground.

  7. The solvent component of macromolecular crystals

    Energy Technology Data Exchange (ETDEWEB)

    Weichenberger, Christian X. [European Academy of Bozen/Bolzano (EURAC), Viale Druso 1, Bozen/Bolzano, I-39100 Südtirol/Alto Adige (Italy); Afonine, Pavel V. [Lawrence Berkeley National Laboratory (LBNL), 1 Cyclotron Road, Mail Stop 64R0121, Berkeley, CA 94720 (United States); Kantardjieff, Katherine [California State University, San Marcos, CA 92078 (United States); Rupp, Bernhard, E-mail: br@hofkristallamt.org [k.-k. Hofkristallamt, 991 Audrey Place, Vista, CA 92084 (United States); Medical University of Innsbruck, Schöpfstrasse 41, A-6020 Innsbruck (Austria)

    2015-04-30

    On average, the mother liquor or solvent and its constituents occupy about 50% of a macromolecular crystal. Ordered as well as disordered solvent components need to be accurately accounted for in modelling and refinement, often with considerable complexity. The mother liquor from which a biomolecular crystal is grown will contain water, buffer molecules, native ligands and cofactors, crystallization precipitants and additives, various metal ions, and often small-molecule ligands or inhibitors. On average, about half the volume of a biomolecular crystal consists of this mother liquor, whose components form the disordered bulk solvent. Its scattering contributions can be exploited in initial phasing and must be included in crystal structure refinement as a bulk-solvent model. Concomitantly, distinct electron density originating from ordered solvent components must be correctly identified and represented as part of the atomic crystal structure model. Herein, are reviewed (i) probabilistic bulk-solvent content estimates, (ii) the use of bulk-solvent density modification in phase improvement, (iii) bulk-solvent models and refinement of bulk-solvent contributions and (iv) modelling and validation of ordered solvent constituents. A brief summary is provided of current tools for bulk-solvent analysis and refinement, as well as of modelling, refinement and analysis of ordered solvent components, including small-molecule ligands.

  8. Issues behind Competitiveness and Carbon Leakage

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This report explores the vulnerability of heavy industry to carbon leakage and competitiveness loss. It reviews the existing literature on competitiveness and carbon leakage under uneven climate policies. It also suggests a statistical method to track carbon leakage, and applies this methodology to Phase I of the EU emissions trading scheme, for various industrial activities: iron and steel, cement, aluminium and refineries. Finally, it reviews measures to mitigate carbon leakage, as discussed in Australia, Canada, Europe, New Zealand and the US.

  9. Macromolecular networks and intelligence in microorganisms

    Science.gov (United States)

    Westerhoff, Hans V.; Brooks, Aaron N.; Simeonidis, Evangelos; García-Contreras, Rodolfo; He, Fei; Boogerd, Fred C.; Jackson, Victoria J.; Goncharuk, Valeri; Kolodkin, Alexey

    2014-01-01

    Living organisms persist by virtue of complex interactions among many components organized into dynamic, environment-responsive networks that span multiple scales and dimensions. Biological networks constitute a type of information and communication technology (ICT): they receive information from the outside and inside of cells, integrate and interpret this information, and then activate a response. Biological networks enable molecules within cells, and even cells themselves, to communicate with each other and their environment. We have become accustomed to associating brain activity – particularly activity of the human brain – with a phenomenon we call “intelligence.” Yet, four billion years of evolution could have selected networks with topologies and dynamics that confer traits analogous to this intelligence, even though they were outside the intercellular networks of the brain. Here, we explore how macromolecular networks in microbes confer intelligent characteristics, such as memory, anticipation, adaptation and reflection and we review current understanding of how network organization reflects the type of intelligence required for the environments in which they were selected. We propose that, if we were to leave terms such as “human” and “brain” out of the defining features of “intelligence,” all forms of life – from microbes to humans – exhibit some or all characteristics consistent with “intelligence.” We then review advances in genome-wide data production and analysis, especially in microbes, that provide a lens into microbial intelligence and propose how the insights derived from quantitatively characterizing biomolecular networks may enable synthetic biologists to create intelligent molecular networks for biotechnology, possibly generating new forms of intelligence, first in silico and then in vivo. PMID:25101076

  10. Macromolecular Topography Leaps into the Digital Age

    Science.gov (United States)

    Lovelace, J.; Bellamy, H.; Snell, E. H.; Borgstahl, G.

    2003-01-01

    A low-cost, real-time digital topography system is under development which will replace x-ray film and nuclear emulsion plates. The imaging system is based on an inexpensive surveillance camera that offers a 1000x1000 array of 8 im square pixels, anti-blooming circuitry, and very quick read out. Currently, the system directly converts x-rays to an image with no phosphor. The system is small and light and can be easily adapted to work with other crystallographic equipment. Preliminary images have been acquired of cubic insulin at the NSLS x26c beam line. NSLS x26c was configured for unfocused monochromatic radiation. Six reflections were collected with stills spaced from 0.002 to 0.001 degrees apart across the entire oscillation range that the reflections were in diffracting condition. All of the reflections were rotated to the vertical to reduce Lorentz and beam related effects. This particular CCD is designed for short exposure applications (much less than 1 sec) and so has a relatively high dark current leading to noisy raw images. The images are processed to remove background and other system noise with a multi-step approach including the use of wavelets, histogram, and mean window filtering. After processing, animations were constructed with the corresponding reflection profile to show the diffraction of the crystal volume vs. the oscillation angle as well as composite images showing the parts of the crystal with the strongest diffraction for each reflection. The final goal is to correlate features seen in reflection profiles captured with fine phi slicing to those seen in the topography images. With this development macromolecular topography finally comes into the digital age.

  11. Heat exchanger leakage problem location

    Directory of Open Access Journals (Sweden)

    Jícha Miroslav

    2012-04-01

    Full Text Available Recent compact heat exchangers are very often assembled from numerous parts joined together to separate heat transfer fluids and to form the required heat exchanger arrangement. Therefore, the leak tightness is very important property of the compact heat exchangers. Although, the compact heat exchangers have been produced for many years, there are still technological problems associated with manufacturing of the ideal connection between the individual parts, mainly encountered with special purpose heat exchangers, e.g. gas turbine recuperators. This paper describes a procedure used to identify the leakage location inside the prime surface gas turbine recuperator. For this purpose, an analytical model of the leaky gas turbine recuperator was created to assess its performance. The results obtained are compared with the experimental data which were acquired during the recuperator thermal performance analysis. The differences between these two data sets are used to indicate possible leakage areas.

  12. Heat exchanger leakage problem location

    Science.gov (United States)

    Hejčík, Jiří; Jícha, Miroslav

    2012-04-01

    Recent compact heat exchangers are very often assembled from numerous parts joined together to separate heat transfer fluids and to form the required heat exchanger arrangement. Therefore, the leak tightness is very important property of the compact heat exchangers. Although, the compact heat exchangers have been produced for many years, there are still technological problems associated with manufacturing of the ideal connection between the individual parts, mainly encountered with special purpose heat exchangers, e.g. gas turbine recuperators. This paper describes a procedure used to identify the leakage location inside the prime surface gas turbine recuperator. For this purpose, an analytical model of the leaky gas turbine recuperator was created to assess its performance. The results obtained are compared with the experimental data which were acquired during the recuperator thermal performance analysis. The differences between these two data sets are used to indicate possible leakage areas.

  13. Complex Macromolecular Architectures by Living Cationic Polymerization

    KAUST Repository

    Alghamdi, Reem D.

    2015-05-01

    Poly (vinyl ether)-based graft polymers have been synthesized by the combination of living cationic polymerization of vinyl ethers with other living or controlled/ living polymerization techniques (anionic and ATRP). The process involves the synthesis of well-defined homopolymers (PnBVE) and co/terpolymers [PnBVE-b-PCEVE-b-PSiDEGVE (ABC type) and PSiDEGVE-b-PnBVE-b-PSiDEGVE (CAC type)] by sequential living cationic polymerization of n-butyl vinyl ether (nBVE), 2-chloroethyl vinyl ether (CEVE) and tert-butyldimethylsilyl ethylene glycol vinyl ether (SiDEGVE), using mono-functional {[n-butoxyethyl acetate (nBEA)], [1-(2-chloroethoxy) ethyl acetate (CEEA)], [1-(2-(2-(t-butyldimethylsilyloxy)ethoxy) ethoxy) ethyl acetate (SiDEGEA)]} or di-functional [1,4-cyclohexanedimethanol di(1-ethyl acetate) (cHMDEA), (VEMOA)] initiators. The living cationic polymerizations of those monomers were conducted in hexane at -20 0C using Et3Al2Cl3 (catalyst) in the presence of 1 M AcOEt base.[1] The PCEVE segments of the synthesized block terpolymers were then used to react with living macroanions (PS-DPE-Li; poly styrene diphenyl ethylene lithium) to afford graft polymers. The quantitative desilylation of PSiDEGVE segments by n-Bu4N+F- in THF at 0 °C led to graft co- and terpolymers in which the polyalcohol is the outer block. These co-/terpolymers were subsequently subjected to “grafting-from” reactions by atom transfer radical polymerization (ATRP) of styrene to afford more complex macromolecular architectures. The base assisted living cationic polymerization of vinyl ethers were also used to synthesize well-defined α-hydroxyl polyvinylether (PnBVE-OH). The resulting polymers were then modified into an ATRP macro-initiator for the synthesis of well-defined block copolymers (PnBVE-b-PS). Bifunctional PnBVE with terminal malonate groups was also synthesized and used as a precursor for more complex architectures such as H-shaped block copolymer by “grafting-from” or

  14. Macromolecular crystallography beamline X25 at the NSLS.

    Science.gov (United States)

    Héroux, Annie; Allaire, Marc; Buono, Richard; Cowan, Matthew L; Dvorak, Joseph; Flaks, Leon; Lamarra, Steven; Myers, Stuart F; Orville, Allen M; Robinson, Howard H; Roessler, Christian G; Schneider, Dieter K; Shea-McCarthy, Grace; Skinner, John M; Skinner, Michael; Soares, Alexei S; Sweet, Robert M; Berman, Lonny E

    2014-05-01

    Beamline X25 at the NSLS is one of the five beamlines dedicated to macromolecular crystallography operated by the Brookhaven National Laboratory Macromolecular Crystallography Research Resource group. This mini-gap insertion-device beamline has seen constant upgrades for the last seven years in order to achieve mini-beam capability down to 20 µm × 20 µm. All major components beginning with the radiation source, and continuing along the beamline and its experimental hutch, have changed to produce a state-of-the-art facility for the scientific community.

  15. Calculating the GONG Leakage Matrix

    Science.gov (United States)

    Hill, F.; Howe, R.

    Since spherical harmonics do not form a complete orthonormal basis set over a portion of a sphere, helioseismic spectra computed for a specific target mode with degree ellt and azimuthal degree mt also contain modes with nearby ell'' and m''. These spatial leaks greatly increase the complexity of the observed spectrum, complicating the spectral fitting and degrading the resulting mode parameter estimates. This is particularly true where the target mode and the leaks have similar frequencies. Some strategies for fitting helioseismic spectra explicitly include the leakage matrix which estimates the relative strength of a mode (ell'' and m'') in the spectrum at (ellt,mt). Since the fitting methods assume that the matrix is correct and apply it as a constraint, an inaccurate matrix introduces systematic errors in the estimated mode parameters. It is thus important to have as accurate a matrix as possible. Here we report on the calculation of the leakage matrix for the GONG observations. The matrix elements are essentially the integrals (over the observed portion of the solar surface) of the crossproducts of the two spherical harmonics. However, several effects have been included to increase the accuracy of the matrix. These include the projection factor of the observable (velocity, intensity, modulation), the spatial apodization applied to the data, the finite rectangular pixel dimensions of the observations, and possible errors in the estimated image geometry. Other factors to be incorporated are the observed MTF, the merging of the GONG images, and the horizontal components of the oscillatory velocity field. We will compare the latest calculation with the observed spectrum and assess the relative importance of the input factors. We will also compare the leakage matrices for velocity and intensity to estimate their contribution to the large apparent differences in the helioseismic spectra obtained from these observables.

  16. Topological qubit design and leakage

    Energy Technology Data Exchange (ETDEWEB)

    Ainsworth, R; Slingerland, J K, E-mail: robert.ainsworth@nuim.ie, E-mail: joost@thphys.nuim.ie [Department of Mathematical Physics, National University of Ireland Maynooth, Co. Kildare (Ireland)

    2011-06-15

    We examine how best to design qubits for use in topological quantum computation. These qubits are topological Hilbert spaces associated with small groups of anyons. Operations are performed on these by exchanging the anyons. One might argue that in order to have as many simple single-qubit operations as possible, the number of anyons per group should be maximized. However, we show that there is a maximal number of particles per qubit, namely 4, and more generally a maximal number of particles for qudits of dimension d. We also look at the possibility of having topological qubits for which one can perform two-qubit gates without leakage into non-computational states. It turns out that the requirement that all two-qubit gates are leakage free is very restrictive and this property can only be realized for two-qubit systems related to Ising-like anyon models, which do not allow for universal quantum computation by braiding. Our results follow directly from the representation theory of braid groups, which implies that they are valid for all anyon models. We also make some remarks about generalizations to other exchange groups.

  17. Air leakage in refrigerated vans. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

    The Air Leakage in Refrigerated Vans Project was initiated by the Department of Energy to assess the impact of air leakage on fuel consumption of highway transport refrigeration equipment. The project, conducted from September of 1977 to December of 1978 collected air leakage data on refrigerated trailers, containers and truck bodies. A Prototype Air Leakage Test Set was developed, designed and constructed to take measurements, and a total of 92 representative vehicles were examined. The results of the study indicate that air leakage causes a 25% increase in the average refrigeration load. However, the majority of transport refrigeration units are equipped with control systems that require the power to be supplied continuously, so that the potential reduction in fuel consumption that can be expected by reduced air leakage is limited. Alternative control techniques and power sources for the control and operation of refrigeration unit components other than the compressor could reduce fuel consumption by approximately 60%.

  18. LEAKAGE OF COLONIC ANASTOMOSIS AFTER COLON RESECTION

    Institute of Scientific and Technical Information of China (English)

    Kanellos I; Pramateftakis MG

    2004-01-01

    Objective To present the diagnosis and management of anastomotic leakage after colon resection. Methods Early diagnosis and urgent therapeutic intervention are required in order to avert life-threatening conditions that may be caused by anastomotic leakage. Results The diagnosis of anastomotic leakage is based on clinical features, peripheral blood investigations and abdominal computed tomography (CT) scan. Major leaks are defined by symptoms of peritonitis and septicaemia due to leakage. Major leaks should be managed operatively. Minor leaks can be managed conservatively with successful outcomes. Conclusion Leakage of colonic anastomosis remains the most serious complication after colon resection. It is a major cause of postoperative morbidity and mortality. A high index of suspicion is required in order to detect early, nonspecific signs of a leakage and urgent surgical intervention is usually required to avert life-threatening events.

  19. Effects of macromolecular crowding and osmolyte on human Tau fibrillation.

    Science.gov (United States)

    Wu, Yingying; Teng, Ningning; Li, Sen

    2016-09-01

    Tau fibrillation is reported to be involved in neurodegenerative disorders, such as Alzheimer's disease, in which the natural environment is very crowded in the cells. Understanding the role of crowding environments in regulating Tau fibrillation is of great importance for elucidating the etiology of these diseases. In this experiment, the effects of macromolecular crowding and osmolyte reagents in the crowding environment on Tau fibrillation were studied by thioflavin T binding, SDS-PAGE and TEM assays. Ficoll 70 and Dextran 70 of different concentrations were used as macromolecular crowding reagents inside the cells and showed a strong enhancing effect on the fibrillation of normal and hyperphosphorylated Tau. The enhancing effect of Dextran is stronger than that of Ficoll 70 at the same concentration. In addition, the cellular osmolyte sucrose was found to protect Tau against fibrillation, and inhibit the enhancing effect of macromolecular crowding on Tau fibrillation. A possible model for the fibrillation process of Tau and the effect of macromolecular crowding and osmolyte on this process was proposed based on these experimental results. The information obtained from our study can enhance the understanding of how proteins aggregate and avoid aggregation in crowded physiological environments and might lead to a better understanding of the molecular mechanisms of Alzheimer's disease in vivo. PMID:26683879

  20. Macromolecular crystallography radiation damage research: what’s new?

    OpenAIRE

    Garman, Elspeth F.; Weik, Martin

    2011-01-01

    Radiation damage in macromolecular crystallography has become a mainstream concern over the last ten years. The current status of research into this area is briefly assessed, and the ten new papers published in this issue are set into the context of previous work in the field. Some novel and exciting developments emerging over the last two years are also summarized.

  1. Generating triangulated macromolecular surfaces by Euclidean Distance Transform.

    Directory of Open Access Journals (Sweden)

    Dong Xu

    Full Text Available Macromolecular surfaces are fundamental representations of their three-dimensional geometric shape. Accurate calculation of protein surfaces is of critical importance in the protein structural and functional studies including ligand-protein docking and virtual screening. In contrast to analytical or parametric representation of macromolecular surfaces, triangulated mesh surfaces have been proved to be easy to describe, visualize and manipulate by computer programs. Here, we develop a new algorithm of EDTSurf for generating three major macromolecular surfaces of van der Waals surface, solvent-accessible surface and molecular surface, using the technique of fast Euclidean Distance Transform (EDT. The triangulated surfaces are constructed directly from volumetric solids by a Vertex-Connected Marching Cube algorithm that forms triangles from grid points. Compared to the analytical result, the relative error of the surface calculations by EDTSurf is <2-4% depending on the grid resolution, which is 1.5-4 times lower than the methods in the literature; and yet, the algorithm is faster and costs less computer memory than the comparative methods. The improvements in both accuracy and speed of the macromolecular surface determination should make EDTSurf a useful tool for the detailed study of protein docking and structure predictions. Both source code and the executable program of EDTSurf are freely available at http://zhang.bioinformatics.ku.edu/EDTSurf.

  2. Two-center-multipole expansion method: application to macromolecular systems

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Yakubovich, Alexander V.; Solov'yov, Andrey V.;

    2007-01-01

    We propose a theoretical method for the calculation of the interaction energy between macromolecular systems at large distances. The method provides a linear scaling of the computing time with the system size and is considered as an alternative to the well-known fast multipole method. Its efficie...

  3. Leakage Power Reduction Using Bitwidth Optimization

    OpenAIRE

    Yasuura, Hiroto

    2002-01-01

    Leakage power dissipation constitutes an increasing fraction of the total power in modern semiconductor technologies. Designing power efficient products will require consideration of leakage power in the earliest phases of design. This paper addresses bitwidth optimization focusing on leakage power reduction for system-level low-power design. By means of tuning the design parameter, bitwidth tailored to a given application requirements, the datapath width of processors and size of memories ar...

  4. Leakage, entrepreneurship, and satisfaction in hospitality

    OpenAIRE

    GALDÓN SALVADOR, JOSÉ LUIS; Garrigós Simón, Fernando José; Gil Pechuán, Ignacio

    2013-01-01

    This is an Accepted Manuscript of an article published by Taylor & Francis in The Service Industries Journal on 2013, available online:http://www.tandfonline.com/10.1080/02642069.2013.740464 Tourism is a very important tool for economic development. However, its economic effects are mainly conditioned by the level of leakage. This work defines leakage, provides an original evaluation of the entrepreneurial environment in showing that it is the one with the lowest level of leakage, and crea...

  5. Practical Leakage-Resilient Symmetric Cryptography

    DEFF Research Database (Denmark)

    Faust, Sebastian; Pietrzak, Krzysztof; Schipper, Joachim

    2012-01-01

    -adaptively. For example, we show that a three round Feistel network instantiated with a leakage resilient PRF yields a leakage resilient PRP if the inputs are chosen non-adaptively (This complements the result of Dodis and Pietrzak [CRYPTO’10] who show that if a adaptive queries are allowed, a superlogarithmic number...... of rounds is necessary.) We also show that a minor variation of the classical GGM construction gives a leakage resilient PRF if both, the leakage-function and the inputs, are chosen non-adaptively...

  6. Valve packing leakage monitoring device

    International Nuclear Information System (INIS)

    A device for monitoring leakage of fluid across a seal in a component connected to a pressurized fluid system including a housing having a chamber with an inlet for receiving fluid leaking across the seal and an outlet. A positioning means is connected to an orifice plug so as to move the plug for permitting the fluid to be discharged through the orifice at the same rate at which it enters the first chamber and means for detecting the movement of the plug is provided to produce and output signal corresponding to the distance moved by the plug and thereby indicate flow rate. The positioning means compromise a piston attached to the plug by a hollow tube and springs, which at low flow rates locate the piston. When flow increases sufficiently pressure increases and urges the piston upwards. A magnetic portion of tube actuates a succession of proximity switches to indicate flow rate. (author)

  7. Quantifying Information Leakage of Randomized Protocols

    DEFF Research Database (Denmark)

    Biondi, Fabrizio; Wasowski, Andrzej; Legay, Axel;

    2013-01-01

    The quantification of information leakage provides a quantitative evaluation of the security of a system. We propose the usage of Markovian processes to model and analyze the information leakage of deterministic and probabilistic systems. We show that this method generalizes the lattice of inform...

  8. Predicting Envelope Leakage in Attached Dwellings

    Energy Technology Data Exchange (ETDEWEB)

    Faakye, O. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Arena, L. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Griffiths, D. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2013-07-01

    The most common method for measuring air leakage is to use a single blower door to pressurize and/or depressurize the test unit. In detached housing, the test unit is the entire home and the single blower door measures air leakage to the outside. In attached housing, this 'single unit', 'total', or 'solo' test method measures both the air leakage between adjacent units through common surfaces as well air leakage to the outside. Measuring and minimizing this total leakage is recommended to avoid indoor air quality issues between units, reduce energy losses to the outside, reduce pressure differentials between units, and control stack effect. However, two significant limitations of the total leakage measurement in attached housing are: for retrofit work, if total leakage is assumed to be all to the outside, the energy benefits of air sealing can be significantly over predicted; for new construction, the total leakage values may result in failing to meet an energy-based house tightness program criterion. The scope of this research is to investigate an approach for developing a viable simplified algorithm that can be used by contractors to assess energy efficiency program qualification and/or compliance based upon solo test results.

  9. Leakage-resilient cryptography from minimal assumptions

    DEFF Research Database (Denmark)

    Hazay, Carmit; López-Alt, Adriana; Wee, Hoeteck;

    2013-01-01

    We present new constructions of leakage-resilient cryptosystems, which remain provably secure even if the attacker learns some arbitrary partial information about their internal secret key. For any polynomial ℓ, we can instantiate these schemes so as to tolerate up to ℓ bits of leakage. While the...

  10. Experimental evaluation of clinical colon anastomotic leakage

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian

    2014-01-01

    , ischemia and insufficient surgical technique have been suggested to play a central role. Animal models are valuable means to evaluate pathophysiological mechanisms and may be used to test preventive measures aiming at reducing the risk of anastomotic leakage, such as external anastomotic coating. The aim...... of this thesis was to: Clarify the best suited animal to model clinical anastomotic leakage in humans; Create animal models mimicking anastomotic leakage in humans induced by insufficient surgical technique and tissue ischemia; Determine the best suited coating materials to prevent anastomotic leakage. STUDY 1...... of experimental animals were identified. The results indicated that the mouse and the pig are the best suited animals to evaluate clinical anastomotic leakage. However, the pig model is less validated and more costly to use compared with the mouse. Most frequently, rats are used as models. However, extreme...

  11. Investigation on correlation of aerosol leakage rate with gas leakage rate in capillary

    International Nuclear Information System (INIS)

    It is necessary to build up the correlation of the aerosol leakage rate with the gas leakage rate for evaluating aerosol leakage of nuclear facilities. The method of evaluating leakage rate of gas and sub-micron aerosol was summarized and also investigated by experiment. The effects of upstream aerosol number concentration, flow velocity and upstream pressure on aerosol leakage were analyzed based on the experimental results. The results show that the aerosol leakage rate is linearly related to the gas leakage rate in capillary when the gas leakage rate is higher than 10-4 Pa · m3 · S-1; the aerosol leakage rate falls sharply due to the diffusion deposition mainly for sub-micron aerosol when the gas le rate is lower than 10-4 Pa · m3 · S-1. The aerosol leakage rate is explored to be expressed as a function of the gas leakage rate and the orifice length under some certain assumptions for practical application. (authors)

  12. Isotope labeling for NMR studies of macromolecular structure and interactions

    Energy Technology Data Exchange (ETDEWEB)

    Wright, P.E. [Scripps Research Institute, La Jolla, CA (United States)

    1994-12-01

    Implementation of biosynthetic methods for uniform or specific isotope labeling of proteins, coupled with the recent development of powerful heteronuclear multidimensional NMR methods, has led to a dramatic increase in the size and complexity of macromolecular systems that are now amenable to NMR structural analysis. In recent years, a new technology has emerged that combines uniform {sup 13}C, {sup 15}N labeling with heteronuclear multidimensional NMR methods to allow NMR structural studies of systems approaching 25 to 30 kDa in molecular weight. In addition, with the introduction of specific {sup 13}C and {sup 15}N labels into ligands, meaningful NMR studies of complexes of even higher molecular weight have become feasible. These advances usher in a new era in which the earlier, rather stringent molecular weight limitations have been greatly surpassed and NMR can begin to address many central biological problems that involve macromolecular structure, dynamics, and interactions.

  13. Macromolecular Brushes as Stabilizers of Hydrophobic Solute Nanoparticles.

    Science.gov (United States)

    Luo, Hanying; Raciti, David; Wang, Chao; Herrera-Alonso, Margarita

    2016-06-01

    Macromolecular brushes bearing poly(ethylene glycol) and poly(d,l-lactide) side chains were used to stabilize hydrophobic solute nanoparticles formed by a rapid change in solvent quality. Unlike linear diblock copolymers with the same hydrophilic and hydrophobic block chemistries, the brush copolymer enabled the formation of ellipsoidal β-carotene nanoparticles, which in cosolvent mixtures developed into rod-like structures, resulting from a combination of Ostwald ripening and particle aggregation. The stabilizing ability of the copolymer was highly dependent on the mobility of the hydrophobic component, influenced by its molecular weight. As shown here, asymmetric amphiphilic macromolecular brushes of this type may be used as hydrophobic drug stabilizers and potentially assist the shape control of nonspherical aggregate morphologies. PMID:27035279

  14. The vibron dressing in α-helicoidal macromolecular chains

    Institute of Scientific and Technical Information of China (English)

    D.(C)evizovi(c); S.Galovi(c); A.Reshetnyak; Z.Ivi(c)

    2013-01-01

    We present a study of the physical properties of the vibrational excitation in α-helicoidal macromolecular chains,caused by the interaction with acoustical and optical phonon modes.The influence of the temperature and the basic system parameters on the vibron dressing have been analyzed by employing the simple mean-field approach based on the variational extension of the Lang-Firsov unitary transformation.The applied approach predicts a region in system parameter space where one has an abrupt transition from a partially dressed (light and mobile) to a fully dressed (immobile) vibron state.We found that the boundary of this region depends on system temperature and the type of bond among structural elements in the macromolecular chain.

  15. Stochastic reaction–diffusion algorithms for macromolecular crowding

    Science.gov (United States)

    Sturrock, Marc

    2016-06-01

    Compartment-based (lattice-based) reaction–diffusion algorithms are often used for studying complex stochastic spatio-temporal processes inside cells. In this paper the influence of macromolecular crowding on stochastic reaction–diffusion simulations is investigated. Reaction–diffusion processes are considered on two different kinds of compartmental lattice, a cubic lattice and a hexagonal close packed lattice, and solved using two different algorithms, the stochastic simulation algorithm and the spatiocyte algorithm (Arjunan and Tomita 2010 Syst. Synth. Biol. 4, 35–53). Obstacles (modelling macromolecular crowding) are shown to have substantial effects on the mean squared displacement and average number of molecules in the domain but the nature of these effects is dependent on the choice of lattice, with the cubic lattice being more susceptible to the effects of the obstacles. Finally, improvements for both algorithms are presented.

  16. Effects of macromolecular chelators on intestinal cadmium absorption in mice

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, O.; Nielsen, J.B.; Bulman, R.A.

    1989-01-01

    Suppression of absorption by macromolecular chelators have been sucessful with several metals. In this paper a series of immobilized chelators ranging from DTPA to S-containing soft bases have been synthetized and investigated for ability to suppress intestinal uptake of /sup 109/Cd/sup 2+/ in mice. Dextran-O-ethyl-mercaptan, xanthates derived from polysaccharides and polyvinyl alcohol, dithiocarbamates of polyethylene imine and aminoethyl cellulose, and DTPA immobilized on aminopropyl silica were all ineffective. DTPA immobilized on aminoethyl cellulose even enhanced the intestinal uptake. The macromolecular chelators were without extensive effect on organ distribution of absorbed cadmium, except for dithiocarbamate immobilized on polyethylene imine, which enhanced the deposition of cadmium in several organs including the brain. Although the results are discouragign, they indicate that desing and synthesis of immobilized vicinal dithio compounds may represent an avenue for development of non-absorbable chelators with high affinity for cadmium.

  17. Integrating Topology and Geometry for Macro-Molecular Simulations

    OpenAIRE

    Moore, Edward L. F.; Peters, Thomas J.; Ferguson, David R.; Neil F Stewart

    2005-01-01

    Emerging macro-molecular simulations, such as supercoiling of DNA and protein unfolding, have an opportunity to profit from two decades of experience with geometric models within computer-aided geometric design (CAGD). For CAGD, static models are often sufficient, while form and function are inextricably related in biochemistry, resulting in greater attention to critical topological characteristics of these dynamic models. The greater emphasis upon dynamic change in macro-...

  18. Single-particle cryo-electron microscopy of macromolecular assemblies

    OpenAIRE

    Cheng, Kimberley

    2009-01-01

    In this thesis, single-particle cryo-electron microscopy (cryo-EM) was used to study the structure of three macromolecular assemblies: the two hemocyanin isoforms from Rapana thomasiana, the Pyrococcus furiosus chaperonin, and the ribosome from Escherichia coli. Hemocyanins are large respiratory proteins in arthropods and molluscs. Most molluscan hemocyanins exist as two distinct isoforms composed of related polypeptides. In most species the two isoforms differ in terms of their oligomeric st...

  19. Climate Policy and Carbon Leakage

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This report explores the effects of the EU emissions trading scheme on the aluminium sector (i.e. competitiveness loss and carbon leakage). With its very high electricity intensity, primary aluminium stands out in the heavy industry picture: a sector whose emissions are not capped in the present EU ETS, European aluminium smelters still stand to lose profit margins and, possibly, market shares, as electricity prices increase following CO2 caps on generators' emissions - the famous pass-through of CO2 prices into electricity prices. The analysis includes a method of quantification of this issue, based on two indicators: profit margins and trade flows. As the EU is at the forefront of such policy, the paper provides policy messages to all countries on how trade exposed energy-intensive industries can be 'moved' by carbon constraint. This also is a contentious topic in Australia, Japan, New Zealand, and the US, where ambitious climate policies -- including cap-and-trade systems -- are currently debated.

  20. Leakage of caesium braquitherapy sources

    International Nuclear Information System (INIS)

    In several Venezuelan public hospitals where cervix uteri tumours are treated by intracavitary radiotherapy, that use manual after loading Fletcher method, with Caesium 137 sources, the use of improper source holders, locally manufactured from pieces of drainage plastic tubing, which deteriorated and created a corrosive environment all around the sources, omission of manufacturer's recommendations regarding corrosion information, source storage, inspection and testing, violation of International Atomic Energy Agency Radiation Protection Procedures, and lack of proper regulatory control, resulted integrity damage to about sixty special form sources (ISO2919 C 63322), leakage of Cs-137 from a supposed insoluble refractory active content (caesium silicoaluminate), and contamination of applicators, floors and bedding. When the situation was detected by means removal contamination tests, after routine inspections, the sources were removed from the hospitals, decontaminated by means of immersion in 3% EDTA solution in ultrasonic bath, subjected to leaking assessment tests, and the ones that passed were placed in low cost stainless steel source holders, designed and built by the instituto Venezolano de Investigaciones Cientificas (IVIC) returned to the hospitals. The leaking sources were removed from use and considered radioactive waste. In order to avoid the occurrence of similar situations, all the importers of such sources are now required to send them to IVIC for testing and placement in proper source holders, before they are shipped to the hospitals. (author)

  1. Macromolecular Assemblage in the Design of a Synthetic AIDS Vaccine

    Science.gov (United States)

    Defoort, Jean-Philippe; Nardelli, Bernardetta; Huang, Wolin; Ho, David D.; Tam, James P.

    1992-05-01

    We describe a peptide vaccine model based on the mimicry of surface coat protein of a pathogen. This model used a macromolecular assemblage approach to amplify peptide antigens in liposomes or micelles. The key components of the model consisted of an oligomeric lysine scaffolding to amplify peptide antigens covalently 4-fold and a lipophilic membrane-anchoring group to further amplify noncovalently the antigens many-fold in liposomal or micellar form. A peptide antigen derived from the third variable domain of glycoprotein gp120 of human immunodeficiency virus type 1 (HIV-1), consisting of neutralizing, T-helper, and T-cytotoxic epitopes, was used in a macromolecular assemblage model (HIV-1 linear peptide amino acid sequence 308-331 in a tetravalent multiple antigen peptide system linked to tripalmitoyl-S-glycerylcysteine). The latter complex, in liposome or micelle, was used to immunize mice and guinea pigs without any adjuvant and found to induce gp120-specific antibodies that neutralize virus infectivity in vitro, elicit cytokine production, and prime CD8^+ cytotoxic T lymphocytes in vivo. Our results show that the macromolecular assemblage approach bears immunological mimicry of the gp120 of HIV virus and may lead to useful vaccines against HIV infection.

  2. Calculation of Leakage Inductance for High Frequency Transformers

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Jun, Zhang; Hurley, William Gerard

    2015-01-01

    Frequency dependent leakage inductance is often observed. High frequency eddy current effects cause a reduction in leakage inductance. The proximity effect between adjacent layers is responsible for the reduction of leakage inductance. This paper gives a detailed analysis of high frequency leakage...... inductance and proposes an accurate prediction methodology. High frequency leakage inductances in several interleaved winding configurations are also discussed. Interleaved winding configurations actually give a smaller degree of reduction of leakage induction at high frequency. Finite Element Analysis (FEA...

  3. Architectural Leakage Power Minimization of Scratchpad memories

    Directory of Open Access Journals (Sweden)

    S. Paraneetharan,

    2012-03-01

    Full Text Available Partitioning a memory into multiple blocks that can be independently accessed is a widely used technique to reduce its dynamic power. For embedded systems, its benefits can be even pushed further by properly matching the partition to the memory access patterns. When leakage energy comes into play, however, idle memory blocks must be put into a proper low-leakage sleep state to actually save energy when not accessed. In this case, the matching becomes an instance of the power management problem, because moving to and from this sleep state requires additional energy. An effective solution to the problem of the leakage-aware partitioning of a memory into disjoint sub blocks, in particular, target scratchpad memories, which are commonly used in some embedded systems as a replacement for caches. By this approach, it is able to provide an optimal solution to the leakage-aware partitioning problem.

  4. Early Alzheimer's Linked to Brain 'Leakage'

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_159116.html Early Alzheimer's Linked to Brain 'Leakage' Normally, blood-brain barrier ... HealthDay News) -- People in the early stages of Alzheimer's disease may have more "leaks" in the barrier ...

  5. Analysis of ONKALO water leakage mapping results

    International Nuclear Information System (INIS)

    As part of the programme for the final disposal of spent nuclear fuel, an analysis has been compiled of water leakage mapping performed in ONKALO. Leakage mapping is part of the Olkiluoto Monitoring Programme (OMO) and the field work has been carried out by Posiva Oy. The main objective of the study is to analyse differences detected between mapping campaigns carried out typically twice a year in 2005-2012. Differences were estimated to be caused by the differences in groundwater conditions caused by seasonal effects or by differences between the years. The effect of technical changes like shotcreting, postgrouting, ventilation etc. on the results was also studied. The development of the visualisation of mapping results was also an objective of this work. Leakage mapping results have been reported yearly in the monitoring reports of Hydrology with some brief comments on the detected differences. In this study, the development of the total area and the number of different leakages as well as the correlation of changes with shotcreting and grouting operations were studied. In addition, traces of fractures on tunnel surfaces, and the location of rock bolts and drain pipes were illustrated together with leakage mapping. In water leakage mapping, the tunnel surfaces are visually mapped to five categories: dry, damp, wet, dripping and flowing. Major changes were detected in the total area of damp leakages. It is likely that the increase has been caused by the condensation of warm ventilation air on the tunnel surfaces and the corresponding decrease by the evaporation of moisture into the dry ventilation air. Shotcreting deep in ONKALO may also have decreased the total area of damp leakages. Changes in the total area and number of wet leakages correlate at least near the surface with differences in yearly precipitation. It is possible that strong rains have also caused a temporary increase in wet leakages. Dripping and wet leakages have been observed on average more

  6. Analysis of ONKALO water leakage mapping results

    Energy Technology Data Exchange (ETDEWEB)

    Ahokas, H.; Nummela, J; Turku, J. [Poeyry Finland Oy, Vantaa (Finland)

    2014-04-15

    As part of the programme for the final disposal of spent nuclear fuel, an analysis has been compiled of water leakage mapping performed in ONKALO. Leakage mapping is part of the Olkiluoto Monitoring Programme (OMO) and the field work has been carried out by Posiva Oy. The main objective of the study is to analyse differences detected between mapping campaigns carried out typically twice a year in 2005-2012. Differences were estimated to be caused by the differences in groundwater conditions caused by seasonal effects or by differences between the years. The effect of technical changes like shotcreting, postgrouting, ventilation etc. on the results was also studied. The development of the visualisation of mapping results was also an objective of this work. Leakage mapping results have been reported yearly in the monitoring reports of Hydrology with some brief comments on the detected differences. In this study, the development of the total area and the number of different leakages as well as the correlation of changes with shotcreting and grouting operations were studied. In addition, traces of fractures on tunnel surfaces, and the location of rock bolts and drain pipes were illustrated together with leakage mapping. In water leakage mapping, the tunnel surfaces are visually mapped to five categories: dry, damp, wet, dripping and flowing. Major changes were detected in the total area of damp leakages. It is likely that the increase has been caused by the condensation of warm ventilation air on the tunnel surfaces and the corresponding decrease by the evaporation of moisture into the dry ventilation air. Shotcreting deep in ONKALO may also have decreased the total area of damp leakages. Changes in the total area and number of wet leakages correlate at least near the surface with differences in yearly precipitation. It is possible that strong rains have also caused a temporary increase in wet leakages. Dripping and wet leakages have been observed on average more

  7. Gate leakage mechanisms in strained Si devices

    Science.gov (United States)

    Yan, L.; Olsen, S. H.; Kanoun, M.; Agaiby, R.; O'Neill, A. G.

    2006-11-01

    This work investigates gate leakage mechanisms in advanced strained Si /SiGe metal-oxide-semiconductor field-effect transistor (MOSFET) devices. The impact of virtual substrate Ge content, epitaxial material quality, epitaxial layer structure, and device processing on gate oxide leakage characteristics are analyzed in detail. In state of the art MOSFETs, gate oxides are only a few nanometers thick. In order to minimize power consumption, leakage currents through the gate must be controlled. However, modifications to the energy band structure, Ge diffusion due to high temperature processing, and Si /SiGe material quality may all affect gate oxide leakage in strained Si devices. We show that at high oxide electric fields where gate leakage is dominated by Fowler-Nordheim tunneling, tensile strained Si MOSFETs exhibit lower leakage levels compared with bulk Si devices. This is a direct result of strain-induced splitting of the conduction band states. However, for device operating regimes at lower oxide electric fields Poole-Frenkel emissions contribute to strained Si gate leakage and increase with increasing virtual substrate Ge content. The emissions are shown to predominantly originate from surface roughness generating bulk oxide traps, opposed to Ge diffusion, and can be improved by introducing a high temperature anneal. Gate oxide interface trap density exhibits a dissimilar behavior and is highly sensitive to Ge atoms at the oxidizing surface, degrading with increasing thermal budget. Consequently advanced strained Si /SiGe devices are inadvertently subject to a potential tradeoff between power consumption (gate leakage current) and device reliability (gate oxide interface quality).

  8. Study on Detection Technique for Pipeline Leakage

    Institute of Scientific and Technical Information of China (English)

    李健; 王立坤; 周琰; 靳世久

    2003-01-01

    Pipeline integrity defect is a considerable portion in all the defects. Therefore, the study on detection technique is of great concern to the owners of pipelines. A real-time monitoring system of pipeline defect is established. For unexpected accidents of pipeline leakage, several methods of signal processing, including wavelet analysis are utilized. The leakage can be located accurately in time. This system is applied to many long distance pipelines in China, which has made great contributions to the economy.

  9. Workshop on algorithms for macromolecular modeling. Final project report, June 1, 1994--May 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Leimkuhler, B.; Hermans, J.; Skeel, R.D.

    1995-07-01

    A workshop was held on algorithms and parallel implementations for macromolecular dynamics, protein folding, and structural refinement. This document contains abstracts and brief reports from that workshop.

  10. Asymmetric gate induced drain leakage and body leakage in vertical MOSFETs with reduced parasitic capacitance

    OpenAIRE

    Gili, E.; Kunz, D.; Uchino, T; Hakim, M. M. A.; De Groot, C. H. (Kees); Ashburn, P.; Hall, S.

    2006-01-01

    Vertical MOSFETs, unlike conventional planar MOSFETs, do not have identical structures at the source and drain, but have very different gate overlaps and geometric configurations. This paper investigates the effect of the asymmetric source and drain geometries of surround-gate vertical MOSFETs on the drain leakage currents in the OFF-state region of operation. Measurements of gate-induced drain leakage (GIDL) and body leakage are carried out as a function of temperature for transistors connec...

  11. Leakage-Resilient Circuits without Computational Assumptions

    DEFF Research Database (Denmark)

    Dziembowski, Stefan; Faust, Sebastian

    2012-01-01

    Physical cryptographic devices inadvertently leak information through numerous side-channels. Such leakage is exploited by so-called side-channel attacks, which often allow for a complete security breache. A recent trend in cryptography is to propose formal models to incorporate leakage into the ......Physical cryptographic devices inadvertently leak information through numerous side-channels. Such leakage is exploited by so-called side-channel attacks, which often allow for a complete security breache. A recent trend in cryptography is to propose formal models to incorporate leakage......: (i) in each observation the leakage is bounded, (ii) different parts of the computation leak independently, and (iii) the randomness that is used for certain operations comes from a simple (non-uniform) distribution. In contrast to earlier work on leakage resilient circuit compilers, which relied...... on computational assumptions, our results are purely information-theoretic. In particular, we do not make use of public key encryption, which was required in all previous works...

  12. The contrasting effect of macromolecular crowding on amyloid fibril formation.

    Directory of Open Access Journals (Sweden)

    Qian Ma

    Full Text Available BACKGROUND: Amyloid fibrils associated with neurodegenerative diseases can be considered biologically relevant failures of cellular quality control mechanisms. It is known that in vivo human Tau protein, human prion protein, and human copper, zinc superoxide dismutase (SOD1 have the tendency to form fibril deposits in a variety of tissues and they are associated with different neurodegenerative diseases, while rabbit prion protein and hen egg white lysozyme do not readily form fibrils and are unlikely to cause neurodegenerative diseases. In this study, we have investigated the contrasting effect of macromolecular crowding on fibril formation of different proteins. METHODOLOGY/PRINCIPAL FINDINGS: As revealed by assays based on thioflavin T binding and turbidity, human Tau fragments, when phosphorylated by glycogen synthase kinase-3β, do not form filaments in the absence of a crowding agent but do form fibrils in the presence of a crowding agent, and the presence of a strong crowding agent dramatically promotes amyloid fibril formation of human prion protein and its two pathogenic mutants E196K and D178N. Such an enhancing effect of macromolecular crowding on fibril formation is also observed for a pathological human SOD1 mutant A4V. On the other hand, rabbit prion protein and hen lysozyme do not form amyloid fibrils when a crowding agent at 300 g/l is used but do form fibrils in the absence of a crowding agent. Furthermore, aggregation of these two proteins is remarkably inhibited by Ficoll 70 and dextran 70 at 200 g/l. CONCLUSIONS/SIGNIFICANCE: We suggest that proteins associated with neurodegenerative diseases are more likely to form amyloid fibrils under crowded conditions than in dilute solutions. By contrast, some of the proteins that are not neurodegenerative disease-associated are unlikely to misfold in crowded physiological environments. A possible explanation for the contrasting effect of macromolecular crowding on these two sets of

  13. Impact of synchrotron radiation on macromolecular crystallography: a personal view

    International Nuclear Information System (INIS)

    This article, largely based on personal experiences of the authors, reviews the early history of the application of synchrotron radiation to structural biology, and particularly protein crystallography, to show the tremendous impact that this experimental innovation has had on these disciplines. The introduction of synchrotron radiation sources almost four decades ago has led to a revolutionary change in the way that diffraction data from macromolecular crystals are being collected. Here a brief history of the development of methodologies that took advantage of the availability of synchrotron sources are presented, and some personal experiences with the utilization of synchrotrons in the early days are recalled

  14. Bringing macromolecular machinery to life using 3D animation.

    Science.gov (United States)

    Iwasa, Janet H

    2015-04-01

    Over the past decade, there has been a rapid rise in the use of three-dimensional (3D) animation to depict molecular and cellular processes. Much of the growth in molecular animation has been in the educational arena, but increasingly, 3D animation software is finding its way into research laboratories. In this review, I will discuss a number of ways in which 3d animation software can play a valuable role in visualizing and communicating macromolecular structures and dynamics. I will also consider the challenges of using animation tools within the research sphere.

  15. How to attribute market leakage to CDM projects

    NARCIS (Netherlands)

    Vöhringer, F.; Kuosmanen, T.K.; Dellink, R.B.

    2006-01-01

    Economic studies suggest that market leakage rates of greenhouse gas abatement can reach the two-digit percentage range. Although the Marrakesh Accords require Clean Development Mechanism (CDM) projects to account for leakage, most projects neglect market leakage. Insufficient leakage accounting is

  16. Pickering unit 1 containment leakage characterization

    International Nuclear Information System (INIS)

    Results of the design pressure test carried out on Pickering Reactor Building number 1 during late 1992 showed that the leakage rate of the building was close to the safety analysis value of 2.7% contained mass per hour at the design pressure of 41.4 kPa(g) and was significantly higher than that reported after the previous test conducted in the spring of 1987. This unexpected finding initiated the longest and the most comprehensive containment leakage investigation ever undertaken by Ontario Hydro. A thorough investigation of leakage behaviour by repeated testing, inspections, leak search and analysis was launched. The extensive leak search effort included items such as: leak source detection by soap solution application, use of ultrasonic detectors, fogging and tracer gas techniques, systematic systems isolation, thermal imaging of the exterior, and quantification of leak sites by flowmeter and bagging. Using a specially designed volumetric technique, the root cause of the problem was finally confirmed as being due to 'pressure dependent laminar leakage' through the hairline cracks in the dome concrete. Structural analysis indicated that the thermal gradients and pressure loading combined to cause the cracking early in the structure's operating history and that overall structural integrity has not been compromised. Leakage rate analysis using a new fluid mechanics model augmented by the effect of thermal strains indicated that the leakage could be significantly less under certain transient temperature gradient conditions. Several options for repairing the dome were considered by a multidisciplinary team and it was finally decided to apply a specially engineered multilayer elastomeric coating to the exterior concrete surface. When the unit was re-tested in October 1993, a dramatic ten-fold improvement in leakage rate (down to 0.25%/h at design pressure) was observed. This is lower than even the commissioning results and comparable to the performance of newer units

  17. Determination of leakage areas in nuclear piping

    Energy Technology Data Exchange (ETDEWEB)

    Keim, E. [Siemens/KWU, Erlangen (Germany)

    1997-04-01

    For the design and operation of nuclear power plants the Leak-Before-Break (LBB) behavior of a piping component has to be shown. This means that the length of a crack resulting in a leak is smaller than the critical crack length and that the leak is safely detectable by a suitable monitoring system. The LBB-concept of Siemens/KWU is based on computer codes for the evaluation of critical crack lengths, crack openings, leakage areas and leakage rates, developed by Siemens/KWU. In the experience with the leak rate program is described while this paper deals with the computation of crack openings and leakage areas of longitudinal and circumferential cracks by means of fracture mechanics. The leakage areas are determined by the integration of the crack openings along the crack front, considering plasticity and geometrical effects. They are evaluated with respect to minimum values for the design of leak detection systems, and maximum values for controlling jet and reaction forces. By means of fracture mechanics LBB for subcritical cracks has to be shown and the calculation of leakage areas is the basis for quantitatively determining the discharge rate of leaking subcritical through-wall cracks. The analytical approach and its validation will be presented for two examples of complex structures. The first one is a pipe branch containing a circumferential crack and the second one is a pipe bend with a longitudinal crack.

  18. Cardiac voltage-gated calcium channel macromolecular complexes.

    Science.gov (United States)

    Rougier, Jean-Sébastien; Abriel, Hugues

    2016-07-01

    Over the past 20years, a new field of research, called channelopathies, investigating diseases caused by ion channel dysfunction has emerged. Cardiac ion channels play an essential role in the generation of the cardiac action potential. Investigators have largely determined the physiological roles of different cardiac ion channels, but little is known about the molecular determinants of their regulation. The voltage-gated calcium channel Cav1.2 shapes the plateau phase of the cardiac action potential and allows the influx of calcium leading to cardiomyocyte contraction. Studies suggest that the regulation of Cav1.2 channels is not uniform in working cardiomyocytes. The notion of micro-domains containing Cav1.2 channels and different calcium channel interacting proteins, called macro-molecular complex, has been proposed to explain these observations. The objective of this review is to summarize the currently known information on the Cav1.2 macromolecular complexes in the cardiac cell and discuss their implication in cardiac function and disorder. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel. PMID:26707467

  19. Protein stabilization by macromolecular crowding through enthalpy rather than entropy.

    Science.gov (United States)

    Senske, Michael; Törk, Lisa; Born, Benjamin; Havenith, Martina; Herrmann, Christian; Ebbinghaus, Simon

    2014-06-25

    The interior of the cell is a densely crowded environment in which protein stability is affected differently than in dilute solution. Macromolecular crowding is commonly understood in terms of an entropic volume exclusion effect based on hardcore repulsions among the macromolecules. We studied the thermal unfolding of ubiquitin in the presence of different cosolutes (glucose, dextran, poly(ethylene glycol), KCl, urea). Our results show that for a correct dissection of the cosolute-induced changes of the free energy into its enthalpic and entropic contributions, the temperature dependence of the heat capacity change needs to be explicitly taken into account. In contrast to the prediction by the excluded volume theory, we observed an enthalpic stabilization and an entropic destabilization for glucose, dextran, and poly(ethylene glycol). The enthalpic stabilization mechanism induced by the macromolecular crowder dextran was similar to the enthalpic stabilization mechanism of its monomeric building block glucose. In the case of poly(ethylene glycol), entropy is dominating over enthalpy leading to an overall destabilization. We propose a new model to classify cosolute effects in terms of their enthalpic contributions to protein stability.

  20. Identifying and Visualizing Macromolecular Flexibility in Structural Biology.

    Science.gov (United States)

    Palamini, Martina; Canciani, Anselmo; Forneris, Federico

    2016-01-01

    Structural biology comprises a variety of tools to obtain atomic resolution data for the investigation of macromolecules. Conventional structural methodologies including crystallography, NMR and electron microscopy often do not provide sufficient details concerning flexibility and dynamics, even though these aspects are critical for the physiological functions of the systems under investigation. However, the increasing complexity of the molecules studied by structural biology (including large macromolecular assemblies, integral membrane proteins, intrinsically disordered systems, and folding intermediates) continuously demands in-depth analyses of the roles of flexibility and conformational specificity involved in interactions with ligands and inhibitors. The intrinsic difficulties in capturing often subtle but critical molecular motions in biological systems have restrained the investigation of flexible molecules into a small niche of structural biology. Introduction of massive technological developments over the recent years, which include time-resolved studies, solution X-ray scattering, and new detectors for cryo-electron microscopy, have pushed the limits of structural investigation of flexible systems far beyond traditional approaches of NMR analysis. By integrating these modern methods with powerful biophysical and computational approaches such as generation of ensembles of molecular models and selective particle picking in electron microscopy, more feasible investigations of dynamic systems are now possible. Using some prominent examples from recent literature, we review how current structural biology methods can contribute useful data to accurately visualize flexibility in macromolecular structures and understand its important roles in regulation of biological processes.

  1. Enzymes as Green Catalysts for Precision Macromolecular Synthesis.

    Science.gov (United States)

    Shoda, Shin-ichiro; Uyama, Hiroshi; Kadokawa, Jun-ichi; Kimura, Shunsaku; Kobayashi, Shiro

    2016-02-24

    The present article comprehensively reviews the macromolecular synthesis using enzymes as catalysts. Among the six main classes of enzymes, the three classes, oxidoreductases, transferases, and hydrolases, have been employed as catalysts for the in vitro macromolecular synthesis and modification reactions. Appropriate design of reaction including monomer and enzyme catalyst produces macromolecules with precisely controlled structure, similarly as in vivo enzymatic reactions. The reaction controls the product structure with respect to substrate selectivity, chemo-selectivity, regio-selectivity, stereoselectivity, and choro-selectivity. Oxidoreductases catalyze various oxidation polymerizations of aromatic compounds as well as vinyl polymerizations. Transferases are effective catalysts for producing polysaccharide having a variety of structure and polyesters. Hydrolases catalyzing the bond-cleaving of macromolecules in vivo, catalyze the reverse reaction for bond forming in vitro to give various polysaccharides and functionalized polyesters. The enzymatic polymerizations allowed the first in vitro synthesis of natural polysaccharides having complicated structures like cellulose, amylose, xylan, chitin, hyaluronan, and chondroitin. These polymerizations are "green" with several respects; nontoxicity of enzyme, high catalyst efficiency, selective reactions under mild conditions using green solvents and renewable starting materials, and producing minimal byproducts. Thus, the enzymatic polymerization is desirable for the environment and contributes to "green polymer chemistry" for maintaining sustainable society.

  2. Macromolecular Crowding Enhances Thermal Stability of Rabbit Muscle Creatine Kinase

    Institute of Scientific and Technical Information of China (English)

    ZHU Jiang; HE Huawei; LI Sen

    2008-01-01

    The effect of dextran on the conformation (or secondary structure) and thermal stability of creatine kinase (CK) was studied using the far-ultraviolet (UV) circular dichroism (CD) spectra.The results showed that lower concentrations of dextran (less than 60 g/L) induced formation of the secondary CK structures.However,the secondary structure content of CK decreased when the dextran concentrations exceeded 60 g/L.Thermally induced transition curves were measured for CK in the presence of different concentrations of dextran by far-UV CD.The thermal transition curves were fitted to a two-state model by a nonlinear,least-squares method to obtain the transition temperature of the unfolding transition.An increase in the tran- sition temperature was observed with the increase of the dextran concentration.These observations qualita-tively accord with predictions of a previously proposed model for the effect of intermolecular excluded volume (macromolecular crowding) on protein stability and conformation.These findings imply that the effects of macromolecular crowding can have an important influence on our understanding of how protein folding oc-curs in vivo.

  3. PRIGo: a new multi-axis goniometer for macromolecular crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Waltersperger, Sandro; Olieric, Vincent, E-mail: vincent.olieric@psi.ch; Pradervand, Claude [Paul Scherrer Institute, Villigen PSI (Switzerland); Glettig, Wayne [Centre Suisse d’Electronique et Microtechnique SA, Neuchâtel 2002 (Switzerland); Salathe, Marco; Fuchs, Martin R.; Curtin, Adrian; Wang, Xiaoqiang; Ebner, Simon; Panepucci, Ezequiel; Weinert, Tobias [Paul Scherrer Institute, Villigen PSI (Switzerland); Schulze-Briese, Clemens [Dectris Ltd, Baden 5400 (Switzerland); Wang, Meitian, E-mail: vincent.olieric@psi.ch [Paul Scherrer Institute, Villigen PSI (Switzerland)

    2015-05-09

    The design and performance of the new multi-axis goniometer PRIGo developed at the Swiss Light Source at Paul Scherrer Institute is described. The Parallel Robotics Inspired Goniometer (PRIGo) is a novel compact and high-precision goniometer providing an alternative to (mini-)kappa, traditional three-circle goniometers and Eulerian cradles used for sample reorientation in macromolecular crystallography. Based on a combination of serial and parallel kinematics, PRIGo emulates an arc. It is mounted on an air-bearing stage for rotation around ω and consists of four linear positioners working synchronously to achieve x, y, z translations and χ rotation (0–90°), followed by a ϕ stage (0–360°) for rotation around the sample holder axis. Owing to the use of piezo linear positioners and active correction, PRIGo features spheres of confusion of <1 µm, <7 µm and <10 µm for ω, χ and ϕ, respectively, and is therefore very well suited for micro-crystallography. PRIGo enables optimal strategies for both native and experimental phasing crystallographic data collection. Herein, PRIGo hardware and software, its calibration, as well as applications in macromolecular crystallography are described.

  4. Risk factors of pancreatic leakage after pancreaticoduodenectomy

    Institute of Scientific and Technical Information of China (English)

    Yin-Mo Yang; Xiao-Dong Tian; Yan Zhuang; Wei-Min Wang; Yuan-Lian Wan; Yan-Ting Huang

    2005-01-01

    AIM: To analyze the risk factors for pancreatic leakage after pancreaticoduodenectomy (PD) and to evaluate whether duct-to-mucosa pancreaticojejunostomy could reduce the risk of pancreatic leakage.METHODS: Sixty-two patients who underwent PD at our hospital between January 2000 and November 2003 were reviewed retrospectively. The primary diseases of the patients included pancreas cancer, ampullary cancer, bile duct cancer, islet cell cancer, duodenal cancer, chronic pancreatitis, pancreatic cystadenoma, and gastric cancer.Standard PD was performed for 25 cases, PD with extended lymphadenectomy for 27 cases, pylorus-preserving PD for 10 cases. A duct-to-mucosa pancreaticojejunostomy was performed for patients with a hard pancreas and a dilated pancreatic duct, and a traditional end-to-end invagination pancreaticojejunostomy for patients with a soft pancreas and a non-dilated duct. Patients were divided into two groups according to the incidence of postoperative pancreaticojejunal anastomotic leakage: 10 cases with leakage and 52 cases without leakage. Seven preoperative and six intraoperative risk factors with the potential to affect the incidence of pancreatic leakage were analyzed with SPSS10.0 software. Logistic regression was then used to determine the effect of multiple factors on pancreatic leakage.RESULTS: Of the 62 patients, 10 (16.13%) were identified as having pancreatic leakage after operation. Other major postoperative complications included delayed gastric emptying (eight patients), abdominal bleeding (four patients), abdominal abscess (three patients) and wound infection (two patients). The overall surgical morbidity was 43.5% (27/62). The hospital mortality in this series was 4.84% (3/62), and the mortality associated with pancreatic fistula was 10% (1/10). Sixteen cases underwent duct-to-mucosa pancreaticojejunostomy and 1 case (1/16, 6.25%) devel-oped postoperative pancreatic leakage, 46 cases underwent invagination pancreaticojejunostomy and 9

  5. Air leakage in residential solar heating systems

    Science.gov (United States)

    Shingleton, J. G.; Cassel, D. E.; Overton, R. L.

    1981-02-01

    A series of computer simulations was performed to evaluate the effects of component air leakage on system thermal performance for a typical residential solar heating system, located in Madison, Wisconsin. Auxiliary energy required to supplement solar energy for space heating was determined using the TRNSYS computer program, for a range of air leakage rates at the solar collector and pebble bed storage unit. The effects of heat transfer and mass transfer between the solar equipment room and the heated building were investigated. The effect of reduced air infiltration into the building due to pressurized by the solar air heating system were determined. A simple method of estimating the effect of collector array air leakage on system thermal performance was evaluated, using the f CHART method.

  6. Component external leakage and rupture frequency estimates

    International Nuclear Information System (INIS)

    In order to perform detailed internal flooding risk analyses of nuclear power plants, external leakage and rupture frequencies are needed for various types of components - piping, valves, pumps, flanges, and others. However, there appears to be no up-to-date, comprehensive source for such frequency estimates. This report attempts to fill that void. Based on a comprehensive search of Licensee Event Reports (LERs) contained in Nuclear Power Experience (NPE), and estimates of component populations and exposure times, component external leakage and rupture frequencies were generated. The remainder of this report covers the specifies of the NPE search for external leakage and rupture events, analysis of the data, a comparison with frequency estimates from other sources, and a discussion of the results

  7. Survey on Techniques for Detecting Data Leakage

    Directory of Open Access Journals (Sweden)

    Bhosale Pranjali A

    2016-06-01

    Full Text Available In current business scenario, critical data is to be shared and transferred by organizations to many stake holders in order to complete particular task. The critical data include intellectual copyright, patient information etc. The activities like sharing and transferring of such critical data includes threats like leakage of information, misuse of data, illegal access to data and/or alteration of data. It is necessary to deal with such problem efficiently and effectively, popular solutions to this problem are use of firewalls, data loss prevention tools and watermarking. But sometimes culprit succeeds in overcoming such security measures hence, if organizations becomes able to find out the guilty client responsible for leakage of particular data then risk of data leakage is reduced. For this many systems are proposed, this paper includes information about techniques discussed in some of such methodologies.

  8. Leakage current measurement in transformerless PV inverters

    DEFF Research Database (Denmark)

    Kerekes, Tamas; Sera, Dezso; Mathe, Laszlo

    2012-01-01

    Photovoltaic (PV) installations have seen a huge increase during the last couple of years. Transformerless PV inverters are gaining more share of the total inverter market, due to their high conversion efficiency, small weight and size. Nevertheless safety should have an important role in case...... of these tranformerless systems, due to the missing galvanic isolation. Leakage and fault current measurement is a key issue for these inverter topologies to be able to comply with the required safety standards. This article presents the test results of two different current measurement sensors that were suggested...... to be used in commercial PV inverters for the measurement of leakage and fault ground currents. The German VDE0126–1–1 standard gives the limit for fault and leakage ground currents and all grid connected PV inverters have to comply with these limits and disconnect from the grid in case of a fault....

  9. Markovian Processes for Quantitative Information Leakage

    DEFF Research Database (Denmark)

    Biondi, Fabrizio

    and randomized processes with Markovian models and to compute their information leakage for a very general model of attacker. We present the QUAIL tool that automates such analysis and is able to compute the information leakage of an imperative WHILE language. Finally, we show how to use QUAIL to analyze some......Quantification of information leakage is a successful approach for evaluating the security of a system. It models the system to be analyzed as a channel with the secret as the input and an output as observable by the attacker as the output, and applies information theory to quantify the amount...... of information transmitted through such channel, thus effectively quantifying how many bits of the secret can be inferred by the attacker by analyzing the system’s output. Channels are usually encoded as matrices of conditional probabilities, known as channel matrices. Such matrices grow exponentially...

  10. Quantifying information leakage of randomized protocols

    DEFF Research Database (Denmark)

    Biondi, Fabrizio; Legay, Axel; Malacaria, Pasquale;

    2015-01-01

    The quantification of information leakage provides a quantitative evaluation of the security of a system. We propose the usage of Markovian processes to model deterministic and probabilistic systems. By using a methodology generalizing the lattice of information approach we model refined attacker...

  11. Poloidal field leakage optimization in ETE

    International Nuclear Information System (INIS)

    A very simple but efficient numerical algorithm is used to minimize the Ohmic coil field leakage into the plasma region of the tokamak ETE. After few interactions the code provides the positions and the current required for two pairs of compensation coils. Resulting optimum field intensity distribution is presented and commented. (author). 5 refs., 4 figs., 2 tabs

  12. Prediction of sodium leakage and combustion phenomena

    International Nuclear Information System (INIS)

    Prediction of sodium leakage and combustion phenomena is important for the safety of liquid metal fast breeder reactors. In particular, small leakage is sensitive to obstacles and air flows. Falling liquid sodium is strongly deformed by separation and dispersion as well as various phenomena, such as combustion and accumulation, are combined. Since the existing finite difference methods need computational grids, it is so difficult to calculate separation and dispersion that small leakage of liquid sodium cannot be analyzed. MPS (Moving Particle Semi-implicit) method is a new numerical method, which is being developed in Univ of Tokyo. In the MPS method fluids are represented by macroscopic particles and governing equations are converted to equivalent particle interactions. Since computational grids are not necessary, separation and dispersion of fluids are easily calculated. Addition of combustion and accumulation will be easy as well because the fluid motion is just simulated by the particle motion. Thus, the objective of the present study is development of a numerical method to predict small size sodium leakage and combustion phenomena. In this paper, a model experiment using water and numerical calculations for this experiment are presented. (J.P.N.)

  13. Large-volume protein crystal growth for neutron macromolecular crystallography.

    Science.gov (United States)

    Ng, Joseph D; Baird, James K; Coates, Leighton; Garcia-Ruiz, Juan M; Hodge, Teresa A; Huang, Sijay

    2015-04-01

    Neutron macromolecular crystallography (NMC) is the prevailing method for the accurate determination of the positions of H atoms in macromolecules. As neutron sources are becoming more available to general users, finding means to optimize the growth of protein crystals to sizes suitable for NMC is extremely important. Historically, much has been learned about growing crystals for X-ray diffraction. However, owing to new-generation synchrotron X-ray facilities and sensitive detectors, protein crystal sizes as small as in the nano-range have become adequate for structure determination, lessening the necessity to grow large crystals. Here, some of the approaches, techniques and considerations for the growth of crystals to significant dimensions that are now relevant to NMC are revisited. These include experimental strategies utilizing solubility diagrams, ripening effects, classical crystallization techniques, microgravity and theoretical considerations.

  14. Identification of macromolecular complexes in cryoelectron tomograms of phantom cells

    Science.gov (United States)

    Frangakis, Achilleas S.; Böhm, Jochen; Förster, Friedrich; Nickell, Stephan; Nicastro, Daniela; Typke, Dieter; Hegerl, Reiner; Baumeister, Wolfgang

    2002-01-01

    Electron tomograms of intact frozen-hydrated cells are essentially three-dimensional images of the entire proteome of the cell, and they depict the whole network of macromolecular interactions. However, this information is not easily accessible because of the poor signal-to-noise ratio of the tomograms and the crowded nature of the cytoplasm. Here, we describe a template matching algorithm that is capable of detecting and identifying macromolecules in tomographic volumes in a fully automated manner. The algorithm is based on nonlinear cross correlation and incorporates elements of multivariate statistical analysis. Phantom cells, i.e., lipid vesicles filled with macromolecules, provide a realistic experimental scenario for an assessment of the fidelity of this approach. At the current resolution of ≈4 nm, macromolecules in the size range of 0.5–1 MDa can be identified with good fidelity. PMID:12391313

  15. A loop of coagulation factor VIIa influencing macromolecular substrate specificity

    DEFF Research Database (Denmark)

    Bjelke, Jais R; Persson, Egon; Rasmussen, Hanne B;

    2006-01-01

    . The resulting variant exhibited increased intrinsic activity, concurrent with maturation of the active site, a less accessible N-terminus, and, interestingly, an altered macromolecular substrate specificity reflected in an increased ability to cleave factor IX (FIX) and a decreased rate of FX activation....../Met(298{156})Lys-FVIIa with almost the same activity and specificity profile. We conclude that a lysine residue in position 298{156} of FVIIa requires a hydrophilic environment to be fully accommodated. This position appears critical for substrate specificity among the proteases of the blood coagulation......Coagulation factor VIIa (FVIIa) belongs to a family of proteases being part of the stepwise, self-amplifying blood coagulation cascade. To investigate the impact of the mutation Met(298{156})Lys in FVIIa, we replaced the Gly(283{140})-Met(298{156}) loop with the corresponding loop of factor Xa...

  16. Macromolecular and dendrimer-based magnetic resonance contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Bumb, Ambika; Brechbiel, Martin W. (Radiation Oncology Branch, National Cancer Inst., National Inst. of Health, Bethesda, MD (United States)), e-mail: pchoyke@mail.nih.gov; Choyke, Peter (Molecular Imaging Program, National Cancer Inst., National Inst. of Health, Bethesda, MD (United States))

    2010-09-15

    Magnetic resonance imaging (MRI) is a powerful imaging modality that can provide an assessment of function or molecular expression in tandem with anatomic detail. Over the last 20-25 years, a number of gadolinium-based MR contrast agents have been developed to enhance signal by altering proton relaxation properties. This review explores a range of these agents from small molecule chelates, such as Gd-DTPA and Gd-DOTA, to macromolecular structures composed of albumin, polylysine, polysaccharides (dextran, inulin, starch), poly(ethylene glycol), copolymers of cystamine and cystine with GD-DTPA, and various dendritic structures based on polyamidoamine and polylysine (Gadomers). The synthesis, structure, biodistribution, and targeting of dendrimer-based MR contrast agents are also discussed

  17. An analysis of fractal geometry of macromolecular gelation

    Institute of Scientific and Technical Information of China (English)

    左榘; 陈天红; 冉少峰; 何炳林; 董宝中; 生文君; 杨恒林

    1996-01-01

    With fractal geometry theory and based on experiments, an analysis of fractal geometry behavior of gelation of macromolecules was carried out. Using the cross-linking copolymerization of styrene-divinylbenzene (DVB) as an example, through the determinations of the evolution of the molecular weight, size and the dependence of scattering intensity on the angle of macromolecules by employing laser and synchrotron small angle X-ray scattering, respectively, this chemical reaction was described quantitatively, its fractal behavior was analyzed and the fractal dimension was also measured. By avoiding the complex theories on gelation, this approach is based on modern physical techniques and theories to perform the analysis of the behavior of fractal geometry of macromolecular gelation and thus is able to reveal the rules of this kind of complicated gelation more essentially and profoundly.

  18. Macromolecular Crystallization with Microfluidic Free-Interface Diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Segelke, B

    2005-02-24

    Fluidigm released the Topaz 1.96 and 4.96 crystallization chips in the fall of 2004. Topaz 1.96 and 4.96 are the latest evolution of Fluidigm's microfluidics crystallization technologies that enable ultra low volume rapid screening for macromolecular crystallization. Topaz 1.96 and 4.96 are similar to each other but represent a major redesign of the Topaz system and have of substantially improved ease of automation and ease of use, improved efficiency and even further reduced amount of material needed. With the release of the new Topaz system, Fluidigm continues to set the standard in low volume crystallization screening which is having an increasing impact in the field of structural genomics, and structural biology more generally. In to the future we are likely to see further optimization and increased utility of the Topaz crystallization system, but we are also likely to see further innovation and the emergence of competing technologies.

  19. Macromolecular contrast agents for MR mammography: current status

    International Nuclear Information System (INIS)

    Macromolecular contrast media (MMCM) encompass a new class of diagnostic drugs that can be applied with dynamic MRI to extract both physiologic and morphologic information in breast lesions. Kinetic analysis of dynamic MMCM-enhanced MR data in breast tumor patients provides useful estimates of tumor blood volume and microvascular permeability, typically increased in cancer. These tumor characteristics can be applied to differentiate benign from malignant lesions, to define the angiogenesis status of cancers, and to monitor tumor response to therapy. The most immediate challenge to the development of MMCM-enhanced mammography is the identification of those candidate compounds that demonstrate the requisite long intravascular distribution and have the high tolerance necessary for clinical use. Potential mammographic applications and limitations of various MMCM, defined by either experimental animal testing or clinical testing in patients, are reviewed in this article. (orig.)

  20. MR lymphography with macromolecular Gd-DTPA compounds

    International Nuclear Information System (INIS)

    This paper investigates the suitability of macromolecular Gd-DTPA compounds as signal-enhancing lymphographic agents in MR imaging. Two Gd-DTPA polylysin compounds and Gd-DTPA albumin, with molecular weights of 48,000,170,000, and 87,000 daltons, respectively, were tested in rabbits at gadolinium doses of 5 and 15 μmol per animal. Three animals were examined at each dose with T1-weighted sequences. The iliac lymph nodes were imaged prior to and during unilateral endolymphatic infusion into a femoral lymph vessel as well as over a period of 2 hours thereafter. All contrast media showed a homogeneous and pronounced signal enhancement in the lymph nodes during infusion at both doses

  1. Facilities for macromolecular crystallography at the Helmholtz-Zentrum Berlin

    International Nuclear Information System (INIS)

    The three macromolecular crystallography beamlines BL14.1, BL14.2 and BL14.3 at the BESSY II storage ring at the Helmholtz-Zentrum Berlin are described. Three macromolecular crystallography (MX) beamlines at the Helmholtz-Zentrum Berlin (HZB) are available for the regional, national and international structural biology user community. The state-of-the-art synchrotron beamlines for MX BL14.1, BL14.2 and BL14.3 are located within the low-β section of the BESSY II electron storage ring. All beamlines are fed from a superconducting 7 T wavelength-shifter insertion device. BL14.1 and BL14.2 are energy tunable in the range 5–16 keV, while BL14.3 is a fixed-energy side station operated at 13.8 keV. All three beamlines are equipped with CCD detectors. BL14.1 and BL14.2 are in regular user operation providing about 200 beam days per year and about 600 user shifts to approximately 50 research groups across Europe. BL14.3 has initially been used as a test facility and was brought into regular user mode operation during the year 2010. BL14.1 has recently been upgraded with a microdiffractometer including a mini-κ goniometer and an automated sample changer. Additional user facilities include office space adjacent to the beamlines, a sample preparation laboratory, a biology laboratory (safety level 1) and high-end computing resources. In this article the instrumentation of the beamlines is described, and a summary of the experimental possibilities of the beamlines and the provided ancillary equipment for the user community is given

  2. Radiation damage to nucleoprotein complexes in macromolecular crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Bury, Charles; Garman, Elspeth F.; Ginn, Helen Mary [University of Oxford, South Parks Road, Oxford OX1 3QU (United Kingdom); Ravelli, Raimond B. G. [Maastricht University, PO Box 616, Maastricht 6200 MD (Netherlands); Carmichael, Ian [University of Notre Dame, Notre Dame, IN 46556 (United States); Kneale, Geoff; McGeehan, John E., E-mail: john.mcgeehan@port.ac.uk [University of Portsmouth, King Henry 1st Street, Portsmouth PO1 2DY (United Kingdom)

    2015-01-30

    Quantitative X-ray induced radiation damage studies employing a model protein–DNA complex revealed a striking partition of damage sites. The DNA component was observed to be far more resistant to specific damage compared with the protein. Significant progress has been made in macromolecular crystallography over recent years in both the understanding and mitigation of X-ray induced radiation damage when collecting diffraction data from crystalline proteins. In contrast, despite the large field that is productively engaged in the study of radiation chemistry of nucleic acids, particularly of DNA, there are currently very few X-ray crystallographic studies on radiation damage mechanisms in nucleic acids. Quantitative comparison of damage to protein and DNA crystals separately is challenging, but many of the issues are circumvented by studying pre-formed biological nucleoprotein complexes where direct comparison of each component can be made under the same controlled conditions. Here a model protein–DNA complex C.Esp1396I is employed to investigate specific damage mechanisms for protein and DNA in a biologically relevant complex over a large dose range (2.07–44.63 MGy). In order to allow a quantitative analysis of radiation damage sites from a complex series of macromolecular diffraction data, a computational method has been developed that is generally applicable to the field. Typical specific damage was observed for both the protein on particular amino acids and for the DNA on, for example, the cleavage of base-sugar N{sub 1}—C and sugar-phosphate C—O bonds. Strikingly the DNA component was determined to be far more resistant to specific damage than the protein for the investigated dose range. At low doses the protein was observed to be susceptible to radiation damage while the DNA was far more resistant, damage only being observed at significantly higher doses.

  3. Platelet function alterations in dengue are associated with plasma leakage

    NARCIS (Netherlands)

    Michels, M.; Alisjahbana, B.; Groot, P.G. de; Indrati, A.R.; Fijnheer, R.; Puspita, M.; Dewi, I.M.; Wijer, L. van de; Boer, E.M. de; Roest, M.; Ven, A.J. van der; Mast, Q. de

    2014-01-01

    Severe dengue is characterised by thrombocytopenia, plasma leakage and bleeding. Platelets are important for preservation of endothelial integrity. We hypothesised that platelet activation with secondary platelet dysfunction contribute to plasma leakage. In adult Indonesian patients with acute dengu

  4. Residential Forced Air System Cabinet Leakage and Blower Performance

    OpenAIRE

    Walker, Iain S.

    2010-01-01

    This project evaluated the air leakage and electric power consumption of Residential HVAC components, with a particular focus on air leakage of furnace cabinets. Laboratory testing of HVAC components indicated that air leakage can be significant and highly variable from unit to unit ? indicating the need for a standard test method and specifying maximum allowable air leakage in California State energy codes. To further this effort, this project provided technical assistance for the developm...

  5. Junction leakage measurements with micro four-point probes

    DEFF Research Database (Denmark)

    Lin, Rong; Petersen, Dirch Hjorth; Wang, Fei;

    2012-01-01

    We present a new, preparation-free method for measuring the leakage current density on ultra-shallow junctions. The junction leakage is found by making a series of four-point sheet resistance measurements on blanket wafers with variable electrode spacings. The leakage current density is calculated...

  6. Leakage Inductance Calculation for Planar Transformers with a Magnetic Shunt

    DEFF Research Database (Denmark)

    Jun, Zhang; Ouyang, Ziwei; Duffy, M. C.;

    2013-01-01

    The magnetic shunt is generally inserted in a planar transformer to increase the leakage inductance which can be utilized as the series inductor in resonant circuits such as the LLC resonant converter. This paper presents a calculation methodology for the leakage inductance of the transformer...... and the experimental results have proven the validity of the proposed calculation method for leakage inductance....

  7. Leakage Inductance Calculation for Planar Transformers with a Magnetic Shunt

    DEFF Research Database (Denmark)

    Zhang, Jun; Ouyang, Ziwei; Duffy, Maeve C.;

    2014-01-01

    The magnetic shunt is generally inserted in a planar transformer to increase the leakage inductance which can be utilized as the series inductor in resonant circuits such as the LLC resonant converter. This paper presents a calculation methodology for the leakage inductance of the transformer...... and the experimental results have proven the validity of the proposed calculation method for leakage inductance....

  8. 49 CFR 192.706 - Transmission lines: Leakage surveys.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Transmission lines: Leakage surveys. 192.706... Transmission lines: Leakage surveys. Leakage surveys of a transmission line must be conducted at intervals not exceeding 15 months, but at least once each calendar year. However, in the case of a transmission line...

  9. Techniques for Leakage Power Reduction in Nanoscale Circuits: A Survey

    DEFF Research Database (Denmark)

    Liu, Wei

    This report surveys progress in the field of designing low power especially low leakage CMOS circuits in deep submicron era. The leakage mechanism and various recently proposed run time leakage reduction techniques are presented. Two designs from Cadence and Sony respectively, which can represent...

  10. Methane leakage in natural gas operations

    International Nuclear Information System (INIS)

    The world gas industry is efficient in conservation of natural gas within its systems. As the influence of methane as an infra-red absorbent gas has been more widely recognized, the considerations of methane's greenhouse effect has become vitally important to gas companies around the world. The industry is universally environmentally conscious. natural gas transmission and distribution companies want to maintain their image as suppliers of clean fuel. Further reductions in methane leakage --- particularly in older distribution systems --- can, should and will be pursued. Unfortunately, there has been little exchange of views on methane leakages between commentators on environmental matters and gas companies and organizations. There is absolutely no need for the industry to avoid the issue of greenhouse gases. Without industry involvement, the environmental debate concerning fossil fuels could lead to selective interpretation of scientific views and available evidence. Companies and authorities would be presented with confusing, contradictory evidence on which to base policy approaches and regulations

  11. Leakage Resilient Secure Two-Party Computation

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Hazay, Carmit; Patra, Arpita

    2012-01-01

    and returns its result. Almost independently of secure computation, the area of {\\em leakage resilient cryptography} has recently been evolving intensively, studying the question of designing cryptographic primitives that remain secure even when some information about the secret key is leaked. In this paper...... Definitions.} We formalize the notion of secure two-party computation in the presence of leakage and introduce security definitions in the {\\em ideal/real framework}. Our formalization induces two types of adversarial attacks. We further study the feasibility of our definitions in the computational setting...... and explore some of the conditions under which these definitions are met. \\item {\\em Composition Theorems.} We provide compositions theorems for our new modelings. Our results provide compositions theorems for the case where the inputs of the parties are sampled from a min-entropy source distribution. \\item...

  12. Inward Leakage in Tight-Fitting PAPRs

    OpenAIRE

    Frank C. Koh; Johnson, Arthur T.; Rehak, Timothy E.

    2011-01-01

    A combination of local flow measurement techniques and fog flow visualization was used to determine the inward leakage for two tight-fitting powered air-purifying respirators (PAPRs), the 3M Breathe-Easy PAPR and the SE 400 breathing demand PAPR. The PAPRs were mounted on a breathing machine head form, and flows were measured from the blower and into the breathing machine. Both respirators leaked a little at the beginning of inhalation, probably through their exhalation valves. In both cases,...

  13. 3DHZETRN: Neutron leakage in finite objects

    Science.gov (United States)

    Wilson, John W.; Slaba, Tony C.; Badavi, Francis F.; Reddell, Brandon D.; Bahadori, Amir A.

    2015-11-01

    The 3DHZETRN formalism was recently developed as an extension to HZETRN with an emphasis on 3D corrections for neutrons and light ions. Comparisons to Monte Carlo (MC) simulations were used to verify the 3DHZETRN methodology in slab and spherical geometry, and it was shown that 3DHZETRN agrees with MC codes to the degree that various MC codes agree among themselves. One limitation of such comparisons is that all of the codes (3DHZETRN and three MC codes) utilize different nuclear models/databases; additionally, using a common nuclear model is impractical due to the complexity of the software. It is therefore difficult to ascertain if observed discrepancies are caused by transport code approximations or nuclear model differences. In particular, an important simplification in the 3DHZETRN formalism assumes that neutron production cross sections can be represented as the sum of forward and isotropic components, where the forward component is subsequently solved within the straight-ahead approximation. In the present report, previous transport model results in specific geometries are combined with additional results in related geometries to study neutron leakage using the Webber 1956 solar particle event as a source boundary condition. A ratio is defined to quantify the fractional neutron leakage at a point in a finite object relative to a semi-infinite slab geometry. Using the leakage ratio removes some of the dependence on the magnitude of the neutron production and clarifies the effects of angular scattering and absorption with regard to differences between the models. Discussion is given regarding observed differences between the MC codes and conclusions drawn about the need for further code development. Although the current version of 3DHZETRN is reasonably accurate compared to MC simulations, this study shows that improved leakage estimates can be obtained by replacing the isotropic/straight-ahead approximation with more detailed descriptions.

  14. Synthesis of a water-soluble macromolecular light stabilizer containing hindered amine structures

    Institute of Scientific and Technical Information of China (English)

    Wei Ma; Mei Meng; Xue Jiang; Bing-Tao Tang; Shu-Fen Zhang

    2013-01-01

    A novel water-soluble macromolecular light stabilizer was synthesized by grafting 2-chloro-4,6-bis-[(2,2,6,6-tetramethylpiperidin-4-yl)amino]-1,3,5-triazine onto polyvinylamine.The intermediate 2-chloro-4,6-bis-[(2,2,6,6-tetramethylpiperidin-4-yl)amino]-1,3,5-triazine and the obtained macromolecular light stabilizer were characterized by 1H NMR,HRMS,IR and UV spectroscopy.Cotton fabrics dyed with C.I.Reactive Yellow 145,C.l.Reactive Red 195 and C.I.Reactive Blue 19 were finished with the macromolecular light stabilizer,and the lightfastness of the dyes was tested.The results showed that the lightfastness of the reactive dyes was improved by 0.5-1.0 grade after being finished and the macromolecular light stabilizer exhibited good wash fastness and thermal stability.

  15. Rapid Metal -free Macromolecular Coupling via in situ Nitrile Oxide-Activated Alkene Cycloaddition

    OpenAIRE

    Isaacman, Michael J.; Cui, Weibin; Theogarajan, Luke S.

    2014-01-01

    Nitrile oxide 1,3 dipolar cycloaddition is a simple and powerful coupling methodology. However, the self-dimerization of nitrile oxides has prevented the widespread use of this strategy for macromolecular coupling. By combining an in situ nitrile oxide generation with a highly reactive activated dipolarophile, we have overcome these obstacles and present a metal-free macromolecular coupling strategy for the modular synthesis of several ABA triblock copolymers. Nitrile oxides were generated in...

  16. NMR RELAXIVITY AND IMAGING OF NEUTRAL MACROMOLECULAR POLYESTER GADOLINIUM (Ⅲ) COMPLEXES

    Institute of Scientific and Technical Information of China (English)

    Kai-chao Yu; Hong-bing Hu; Mai-li Liu; Han-zhen Yuan; Chao-hui Ye; Ren-xi Zhuo

    1999-01-01

    Five neutral macromolecular polyester gadolinium (Ⅲ) complexes with pendant hydrophobic alkyl and aromatic functional groups were prepared. The longitudinal relaxation rates of these complexes were measured. One of these Gd (Ⅲ) complexes was chosen for the acute toxicity test and T1-weighted imaging measurement. Preliminary results showed that. compared with Gd-DTPA, the neutral macromolecular gadolinium (Ⅲ) complexes provide higher T1 relaxivity enhancement and longer function duration.

  17. Alopecia associated with unexpected leakage from electron cone

    International Nuclear Information System (INIS)

    Excessive irradiation due to unexpected leakage was found on a patient receiving electron beam therapy. The cause of this leakage was analyzed and the amount of leakage was measured for different electron beam energies. The highest leakage occurred with a 6 x 6 cm cone using a 12 MeV electron beam. The leakage dose measured along the side of the cone could be as great as 40%. Until the cones are modified or redesigned, it is advised that all patient setups be carefully reviewed to assure that no significant patient areas are in the side scatter region

  18. TRACKING DOWN DATA LEAKAGE BY USING ENCRYPTED FAKE OBJECTS

    OpenAIRE

    Anugu Rahul Reddy; BalaKrishna Bangaru

    2014-01-01

    This paper contains concept of data leakage, its causes of leakage and different techniques to protect and detect the data leakage. The value of the data is incredible, so it should not be leaked or altered. In the field of IT, huge database is being used. This database is shared with multiple people at a time. But during this sharing of the data, there are huge chances of data vulnerability, leakage or alteration. So, to prevent these problems, a data leakage detection system has...

  19. Alopecia associated with unexpected leakage from electron cone

    Energy Technology Data Exchange (ETDEWEB)

    Wen, B.C.; Pennington, E.C.; Hussey, D.H.; Jani, S.K.

    1989-06-01

    Excessive irradiation due to unexpected leakage was found on a patient receiving electron beam therapy. The cause of this leakage was analyzed and the amount of leakage was measured for different electron beam energies. The highest leakage occurred with a 6 x 6 cm cone using a 12 MeV electron beam. The leakage dose measured along the side of the cone could be as great as 40%. Until the cones are modified or redesigned, it is advised that all patient setups be carefully reviewed to assure that no significant patient areas are in the side scatter region.

  20. Project Boundary Setting and Leakage Treatment in CDM Project

    Institute of Scientific and Technical Information of China (English)

    ZOU Chen; WANG Shujuan; DUAN Maosheng; CHEN Changhe

    2005-01-01

    Project boundary setting and leakage treatment are two important issues to be considered when a clean development mechanism (CDM) project is being designed. There are still many uncertainties concerning these two issues. This paper reviews the concepts of project boundary setting and leakage in CDM projects, cites the types and sources of leakage, discusses the principles for determining leakage, and gives some proposed methods for dealing with leakage. A case study, using several steps to solve the boundary and leakage problems,shows how the analyzed principles and treatments can be implemented in a real project. Based on the result of the case study, the methods discussed are shown to be appropriate for settling leakage issues.

  1. FELERION: a new approach for leakage power reduction

    Science.gov (United States)

    R, Anjana; Somkuwar, Ajay

    2014-12-01

    The circuit proposed in this paper simultaneously reduces the sub threshold leakage power and saves the state of art aspect of the logic circuits. Sleep transistors and PMOS-only logic are used to further reduce the leakage power. Sleep transistors are used as the keepers to reduce the sub threshold leakage current providing the low resistance path to the output. PMOS-only logic is used between the pull up and pull down devices to mitigate the leakage power further. Our proposed fast efficient leakage reduction circuit not only reduces the leakage current but also reduces the power dissipation. Power and delay are analyzed at the 32 nm BSIM4 model for a chain of four inverters, NAND, NOR and ISCAS-85 c17 benchmark circuits using DSCH3 and the Microwind tool. The simulation results reveal that our proposed approach mitigates leakage power by 90%-94% as compared to the conventional approach.

  2. JBluIce-EPICS control system for macromolecular crystallography

    International Nuclear Information System (INIS)

    The trio of macromolecular crystallography beamlines constructed by the General Medicine and Cancer Institutes Collaborative Access Team (GM/CA-CAT) in Sector 23 of the Advanced Photon Source (APS) have been in growing demand owing to their outstanding beam quality and capacity to measure data from crystals of only a few micrometres in size. To take full advantage of the state-of-the-art mechanical and optical design of these beamlines, a significant effort has been devoted to designing fast, convenient, intuitive and robust beamline controls that could easily accommodate new beamline developments. The GM/CA-CAT beamline controls are based on the power of EPICS for distributed hardware control, the rich Java graphical user interface of Eclipse RCP and the task-oriented philosophy as well as the look and feel of the successful SSRL BluIce graphical user interface for crystallography. These beamline controls feature a minimum number of software layers, the wide use of plug-ins that can be written in any language and unified motion controls that allow on-the-fly scanning and optimization of any beamline component. This paper describes the ways in which BluIce was combined with EPICS and converted into the Java-based JBluIce, discusses the solutions aimed at streamlining and speeding up operations and gives an overview of the tools that are provided by this new open-source control system for facilitating crystallographic experiments, especially in the field of microcrystallography.

  3. Canadian macromolecular crystallography facility: a suite of fully automated beamlines.

    Science.gov (United States)

    Grochulski, Pawel; Fodje, Michel; Labiuk, Shaunivan; Gorin, James; Janzen, Kathryn; Berg, Russ

    2012-06-01

    The Canadian light source is a 2.9 GeV national synchrotron radiation facility located on the University of Saskatchewan campus in Saskatoon. The small-gap in-vacuum undulator illuminated beamline, 08ID-1, together with the bending magnet beamline, 08B1-1, constitute the Canadian Macromolecular Crystallography Facility (CMCF). The CMCF provides service to more than 50 Principal Investigators in Canada and the United States. Up to 25% of the beam time is devoted to commercial users and the general user program is guaranteed up to 55% of the useful beam time through a peer-review process. CMCF staff provides "Mail-In" crystallography service to users with the highest scored proposals. Both beamlines are equipped with very robust end-stations including on-axis visualization systems, Rayonix 300 CCD series detectors and Stanford-type robotic sample auto-mounters. MxDC, an in-house developed beamline control system, is integrated with a data processing module, AutoProcess, allowing full automation of data collection and data processing with minimal human intervention. Sample management and remote monitoring of experiments is enabled through interaction with a Laboratory Information Management System developed at the facility.

  4. Macromolecular Powder Diffraction: Ready for genuine biological problems.

    Science.gov (United States)

    Karavassili, Fotini; Margiolaki, Irene

    2016-01-01

    Knowledge of 3D structures of biological molecules plays a major role in both understanding important processes of life and developing pharmaceuticals. Among several methods available for structure determination, macromolecular X-ray powder diffraction (XRPD) has transformed over the past decade from an impossible dream to a respectable method. XRPD can be employed in biosciences for various purposes such as observing phase transitions, characterizing bulk pharmaceuticals, determining structures via the molecular replacement method, detecting ligands in protein-ligand complexes, as well as combining micro-sized single crystal crystallographic data and powder diffraction data. Studies using synchrotron and laboratory sources in some standard configuration setups are reported in this review, including their respective advantages and disadvantages. Methods presented here provide an alternative, complementary set of tools to resolve structural problems. A variety of already existing software packages for powder diffraction data processing and analysis, some of which have been adapted to large unit cell studies, are briefly described. This review aims to provide necessary elements of theory and current methods, along with practical explanations, available software packages and highlighted case studies. PMID:26786768

  5. Macromolecular metallurgy of binary mesocrystals via designed multiblock terpolymers.

    Science.gov (United States)

    Xie, Nan; Liu, Meijiao; Deng, Hanlin; Li, Weihua; Qiu, Feng; Shi, An-Chang

    2014-02-26

    Self-assembling block copolymers provide access to the fabrication of various ordered phases. In particular, the ordered spherical phases can be used to engineer soft mesocrystals with domain size at the 5-100 nm scales. Simple block copolymers, such as diblock copolymers, form a limited number of mesocrystals. However multiblock copolymers are capable to form more complex mesocrystals. We demonstrate that designed B1AB2CB3 multiblock terpolymers, in which the A- and C-blocks form spherical domains and the packing of these spheres can be controlled by changing the lengths of the middle and terminal B-blocks, self-assemble into various binary mesocrystals with space group symmetries of a large number of binary ionic crystals, including NaCl, CsCl, ZnS, α-BN, AlB2, CaF2, TiO2, ReO3, Li3Bi, Nb3Sn(A15), and α-Al2O3. This approach can be generalized to other terpolymers as well as to tetrapolymers to obtain ternary mesocrystals. Our study provides a new concept of macromolecular metallurgy for producing crystal phases in a mesoscale and thus makes multiblock copolymers a robust platform for the engineering of functional materials.

  6. Patch-clamp detection of macromolecular translocation along nuclear pores

    Directory of Open Access Journals (Sweden)

    Bustamante J.O.

    1998-01-01

    Full Text Available The present paper reviews the application of patch-clamp principles to the detection and measurement of macromolecular translocation along the nuclear pores. We demonstrate that the tight-seal 'gigaseal' between the pipette tip and the nuclear membrane is possible in the presence of fully operational nuclear pores. We show that the ability to form a gigaseal in nucleus-attached configurations does not mean that only the activity of channels from the outer membrane of the nuclear envelope can be detected. Instead, we show that, in the presence of fully operational nuclear pores, it is likely that the large-conductance ion channel activity recorded derives from the nuclear pores. We conclude the technical section with the suggestion that the best way to demonstrate that the nuclear pores are responsible for ion channel activity is by showing with fluorescence microscopy the nuclear translocation of ions and small molecules and the exclusion of the same from the cisterna enclosed by the two membranes of the envelope. Since transcription factors and mRNAs, two major groups of nuclear macromolecules, use nuclear pores to enter and exit the nucleus and play essential roles in the control of gene activity and expression, this review should be useful to cell and molecular biologists interested in understanding how patch-clamp can be used to quantitate the translocation of such macromolecules into and out of the nucleus

  7. Macromolecular coal structure as revealed by novel diffusion tests

    Energy Technology Data Exchange (ETDEWEB)

    Peppas, N.A.; Olivares, J.; Drummond, R.; Lustig, S.

    1990-01-01

    The main goal of the present work was the elucidation of the mechanistic characteristics of dynamic transport of various penetrants (solvents) in thin sections of coals by examining their penetrant uptake, front swelling and stress development. An important objective of this work was the study of coal network structure in different thermodynamically compatible penetrants and the analysis of dynamic swelling in terms of present anomalous transport theories. Interferometry/polariscopy, surface image analysis and related techniques were used to quantify the stresses and solvent concentration profiles in these sections. Dynamic and equilibrium swelling behavior were correlated using the polar interaction contributions of the solvent solubility parameters. The penetrant front position was followed in thin coal sections as a function of time. The initial front velocity was calculated for various coals and penetrants. Our penetrant studies with thin coal section from the same coal sample but with different thickness show that within the range of 150 {mu}m to 1500{mu}m the transport mechanism of dimethyl formamide in the macromolecular coal network is non-Fickian. In fact, for the thickest samples the transport mechanism is predominately Case-II whereas in the thinner samples penetrant uptake may be diffusion-controlled. Studies in various penetrants such as acetone, cyclohexane, methanol, methyl ethyl ketone, toluene and methylene chloride indicated that penetrant transport is a non-Fickian phenomenon. Stresses and cracks were observed for transport of methylene chloride. 73 refs., 88 figs., 15 tabs.

  8. Synchrotron radiation macromolecular crystallography: science and spin-offs

    Directory of Open Access Journals (Sweden)

    John R. Helliwell

    2015-03-01

    Full Text Available A current overview of synchrotron radiation (SR in macromolecular crystallography (MX instrumentation, methods and applications is presented. Automation has been and remains a central development in the last decade, as have the rise of remote access and of industrial service provision. Results include a high number of Protein Data Bank depositions, with an increasing emphasis on the successful use of microcrystals. One future emphasis involves pushing the frontiers of using higher and lower photon energies. With the advent of X-ray free-electron lasers, closely linked to SR developments, the use of ever smaller samples such as nanocrystals, nanoclusters and single molecules is anticipated, as well as the opening up of femtosecond time-resolved diffraction structural studies. At SR sources, a very high-throughput assessment for the best crystal samples and the ability to tackle just a few micron and sub-micron crystals will become widespread. With higher speeds and larger detectors, diffraction data volumes are becoming long-term storage and archiving issues; the implications for today and the future are discussed. Together with the rise of the storage ring to its current pre-eminence in MX data provision, the growing tendency of central facility sites to offer other centralized facilities complementary to crystallography, such as cryo-electron microscopy and NMR, is a welcome development.

  9. JBluIce-EPICS control system for macromolecular crystallography.

    Energy Technology Data Exchange (ETDEWEB)

    Stepanov, S.; Makarov, O.; Hilgart, M.; Pothineni, S.; Urakhchin, A.; Devarapalli, S.; Yoder, D.; Becker, M.; Ogata, C.; Sanishvili, R.; Nagarajan, V.; Smith, J. L.; Fischetti, R. F. (Biosciences Division); (Univ. of Michigan)

    2011-01-01

    The trio of macromolecular crystallography beamlines constructed by the General Medicine and Cancer Institutes Collaborative Access Team (GM/CA-CAT) in Sector 23 of the Advanced Photon Source (APS) have been in growing demand owing to their outstanding beam quality and capacity to measure data from crystals of only a few micrometres in size. To take full advantage of the state-of-the-art mechanical and optical design of these beamlines, a significant effort has been devoted to designing fast, convenient, intuitive and robust beamline controls that could easily accommodate new beamline developments. The GM/CA-CAT beamline controls are based on the power of EPICS for distributed hardware control, the rich Java graphical user interface of Eclipse RCP and the task-oriented philosophy as well as the look and feel of the successful SSRL BluIce graphical user interface for crystallography. These beamline controls feature a minimum number of software layers, the wide use of plug-ins that can be written in any language and unified motion controls that allow on-the-fly scanning and optimization of any beamline component. This paper describes the ways in which BluIce was combined with EPICS and converted into the Java-based JBluIce, discusses the solutions aimed at streamlining and speeding up operations and gives an overview of the tools that are provided by this new open-source control system for facilitating crystallographic experiments, especially in the field of microcrystallography.

  10. Polycapillary x-ray optics for macromolecular crystallography

    International Nuclear Information System (INIS)

    Polycapillary x-ray optics have found potential application in many different fields, including antiscatter and magnification in mammography, radiography, x-ray fluorescence, x-ray lithography, and x-ray diffraction techniques. In x-ray diffraction, an optic is used to collect divergent x-rays from a point source and redirect them into a quasi-parallel, or slightly focused beam. Monolithic polycapillary optics have been developed recently for macromolecular crystallography and have already shown considerable gains in diffracted beam intensity over pinhole collimation. Development is being pursued through a series of simulations and prototype optics. Many improvements have been made over the stage 1 prototype reported previously, which include better control over the manufacturing process, reducing the diameter of the output beam, and addition of a slight focusing at the output of the optic to further increase x-ray flux at the sample. The authors report the characteristics and performance of the stage 1 and stage 2 optics

  11. Automated identification of elemental ions in macromolecular crystal structures

    International Nuclear Information System (INIS)

    The solvent-picking procedure in phenix.refine has been extended and combined with Phaser anomalous substructure completion and analysis of coordination geometry to identify and place elemental ions. Many macromolecular model-building and refinement programs can automatically place solvent atoms in electron density at moderate-to-high resolution. This process frequently builds water molecules in place of elemental ions, the identification of which must be performed manually. The solvent-picking algorithms in phenix.refine have been extended to build common ions based on an analysis of the chemical environment as well as physical properties such as occupancy, B factor and anomalous scattering. The method is most effective for heavier elements such as calcium and zinc, for which a majority of sites can be placed with few false positives in a diverse test set of structures. At atomic resolution, it is observed that it can also be possible to identify tightly bound sodium and magnesium ions. A number of challenges that contribute to the difficulty of completely automating the process of structure completion are discussed

  12. EVA Suit Microbial Leakage Investigation Project

    Science.gov (United States)

    Falker, Jay; Baker, Christopher; Clayton, Ronald; Rucker, Michelle

    2016-01-01

    The objective of this project is to collect microbial samples from various EVA suits to determine how much microbial contamination is typically released during simulated planetary exploration activities. Data will be released to the planetary protection and science communities, and advanced EVA system designers. In the best case scenario, we will discover that very little microbial contamination leaks from our current or prototype suit designs, in the worst case scenario, we will identify leak paths, learn more about what affects leakage--and we'll have a new, flight-certified swab tool for our EVA toolbox.

  13. Analysis of U.S. residential air leakage database

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Wanyu R.; Price, Phillip N.; Sohn, Michael D.; Gadgil, Ashok J.

    2003-07-01

    The air leakage of a building envelope can be determined from fan pressurization measurements with a blower door. More than 70,000 air leakage measurements have been compiled into a database. In addition to air leakage, the database includes other important characteristics of the dwellings tested, such as floor area, year built, and location. There are also data for some houses on the presence of heating ducts, and floor/basement construction type. The purpose of this work is to identify house characteristics that can be used to predict air leakage. We found that the distribution of leakage normalized with floor area of the house is roughly lognormal. Year built and floor area are the two most significant factors to consider when predicting air leakage: older and smaller houses tend to have higher normalized leakage areas compared to newer and larger ones. Results from multiple linear regression of normalized leakage with respect to these two factors are presented for three types of houses: low-income, energy-efficient, and conventional. We demonstrate a method of using the regression model in conjunction with housing characteristics published by the US Census Bureau to derive a distribution that describes the air leakage of the single-family detached housing stock. Comparison of our estimates with published datasets of air exchange rates suggests that the regression model generates accurate estimates of air leakage distribution.

  14. DOMMINO 2.0: integrating structurally resolved protein-, RNA-, and DNA-mediated macromolecular interactions.

    Science.gov (United States)

    Kuang, Xingyan; Dhroso, Andi; Han, Jing Ginger; Shyu, Chi-Ren; Korkin, Dmitry

    2016-01-01

    Macromolecular interactions are formed between proteins, DNA and RNA molecules. Being a principle building block in macromolecular assemblies and pathways, the interactions underlie most of cellular functions. Malfunctioning of macromolecular interactions is also linked to a number of diseases. Structural knowledge of the macromolecular interaction allows one to understand the interaction's mechanism, determine its functional implications and characterize the effects of genetic variations, such as single nucleotide polymorphisms, on the interaction. Unfortunately, until now the interactions mediated by different types of macromolecules, e.g. protein-protein interactions or protein-DNA interactions, are collected into individual and unrelated structural databases. This presents a significant obstacle in the analysis of macromolecular interactions. For instance, the homogeneous structural interaction databases prevent scientists from studying structural interactions of different types but occurring in the same macromolecular complex. Here, we introduce DOMMINO 2.0, a structural Database Of Macro-Molecular INteractiOns. Compared to DOMMINO 1.0, a comprehensive database on protein-protein interactions, DOMMINO 2.0 includes the interactions between all three basic types of macromolecules extracted from PDB files. DOMMINO 2.0 is automatically updated on a weekly basis. It currently includes ∼1,040,000 interactions between two polypeptide subunits (e.g. domains, peptides, termini and interdomain linkers), ∼43,000 RNA-mediated interactions, and ∼12,000 DNA-mediated interactions. All protein structures in the database are annotated using SCOP and SUPERFAMILY family annotation. As a result, protein-mediated interactions involving protein domains, interdomain linkers, C- and N- termini, and peptides are identified. Our database provides an intuitive web interface, allowing one to investigate interactions at three different resolution levels: whole subunit network

  15. A Compact X-Ray System for Macromolecular Crystallography. 5

    Science.gov (United States)

    Gubarev, Mikhail; Ciszak, Ewa; Ponomarev, Igor; Joy, Marshall

    2000-01-01

    We describe the design and performance of a high flux x-ray system for macromolecular crystallography that combines a microfocus x-ray generator (40 gm FWHM spot size at a power level of 46.5Watts) and a 5.5 mm focal distance polycapillary optic. The Cu K(sub alpha) X-ray flux produced by this optimized system is 7.0 times above the X-ray flux previously reported. The X-ray flux from the microfocus system is also 3.2 times higher than that produced by the rotating anode generator equipped with a long focal distance graded multilayer monochromator (Green optic; CMF24-48-Cu6) and 30% less than that produced by the rotating anode generator with the newest design of graded multilayer monochromator (Blue optic; CMF12-38-Cu6). Both rotating anode generators operate at a power level of 5000 Watts, dissipating more than 100 times the power of our microfocus x-ray system. Diffraction data collected from small test crystals are of high quality. For example, 42,540 reflections collected at ambient temperature from a lysozyme crystal yielded R(sub sym) 5.0% for the data extending to 1.7A, and 4.8% for the complete set of data to 1.85A. The amplitudes of the reflections were used to calculate difference electron density maps that revealed positions of structurally important ions and water molecules in the crystal of lysozyme using the phases calculated from the protein model.

  16. A Compact X-Ray System for Macromolecular Crystallography

    Science.gov (United States)

    Gubarev, Mikhail; Ciszak, Ewa; Ponomarev, Igor; Gibson, Walter; Joy, Marshall

    2000-01-01

    We describe the design and performance of a high flux x-ray system for a macromolecular crystallography that combines a microfocus x-ray generator (40 micrometer full width at half maximum spot size at a power level of 46.5 W) and a collimating polycapillary optic. The Cu Ka lpha x-ray flux produced by this optimized system through a 500,um diam orifice is 7.0 times greater than the x-ray flux previously reported by Gubarev et al. [M. Gubarev et al., J. Appl. Crystallogr. 33, 882 (2000)]. The x-ray flux from the microfocus system is also 2.6 times higher than that produced by a rotating anode generator equipped with a graded multilayer monochromator (green optic, Osmic Inc. CMF24-48-Cu6) and 40% less than that produced by a rotating anode generator with the newest design of graded multilayer monochromator (blue optic, Osmic, Inc. CMF12-38-Cu6). Both rotating anode generators operate at a power level of 5000 W, dissipating more than 100 times the power of our microfocus x-ray system. Diffraction data collected from small test crystals are of high quality. For example, 42 540 reflections collected at ambient temperature from a lysozyme crystal yielded R(sub sym)=5.0% for data extending to 1.70 A, and 4.8% for the complete set of data to 1.85 A. The amplitudes of the observed reflections were used to calculate difference electron density maps that revealed positions of structurally important ions and water molecules in the crystal of lysozyme using the phases calculated from the protein model.

  17. Macromolecular compositions of phytoplankton in the Amundsen Sea, Antarctica

    Science.gov (United States)

    Kim, Bo Kyung; Lee, Jang Han; Joo, HuiTae; Song, Ho Jung; Yang, Eun Jin; Lee, Sang Hoon; Lee, Sang H.

    2016-01-01

    The biochemical compositions (proteins, carbohydrates, and lipids) of phytoplankton provide useful information for their environmental growth conditions and nutritional status as a basic food source for upper trophic consumers. Concentrations of these compositions were assessed at 100, 30, and 1% light penetration depths within the euphotic zone in the Amundsen Sea, Antarctica, using colorimetric techniques. The major inorganic nutrients were generally abundant throughout the study area. The average chlorophyll a (chl-a) concentration was 49.2 mg m-2 (S.D.=±27.6 mg m-2) and large phytoplankton (>20 μm) accounted for 64.1% of the total chl-a concentration. The biochemical compositions of the phytoplankton were not significantly different among different light depths or productivity stations. The overall compositions of proteins, carbohydrates, and lipids from all stations averaged 65.9% (S.D.=±12.5%), 22.4% (S.D.=±10.9%), and 11.7% (S.D.=±6.5%), respectively. Regardless of dominant phytoplankton species, nitrogen-abundant conditions sustained high protein compositions of phytoplankton in the Amundsen Sea during the cruise period. Based on the macromolecular compositions, the average food material (FM) concentration was 219.4 μg L-1 (S.D.=±151.1 μg L-1) and correlated positively with the primary productivity in the Amundsen Sea. High protein/carbohydrate ratios (>1) and large proportions of proteins suggest that phytoplankton provide nitrogen-sufficient foods to higher trophic consumers through a higher efficiency of protein carbon incorporated into herbivores.

  18. A simple quantitative model of macromolecular crowding effects on protein folding: Application to the murine prion protein(121-231)

    Science.gov (United States)

    Bergasa-Caceres, Fernando; Rabitz, Herschel A.

    2013-06-01

    A model of protein folding kinetics is applied to study the effects of macromolecular crowding on protein folding rate and stability. Macromolecular crowding is found to promote a decrease of the entropic cost of folding of proteins that produces an increase of both the stability and the folding rate. The acceleration of the folding rate due to macromolecular crowding is shown to be a topology-dependent effect. The model is applied to the folding dynamics of the murine prion protein (121-231). The differential effect of macromolecular crowding as a function of protein topology suffices to make non-native configurations relatively more accessible.

  19. EM information leakage from display unit and visual inspection for its leakage source

    Science.gov (United States)

    Watanabe, Takashi; Sako, Hiroshi

    2013-05-01

    Display unit emits a small amount of electromagnetic wave. Although it is weak enough to prevent interference with human body, information leaks through it. This paper presents an experiment on exploring the leakage source by visually inspecting the screen images reconstructed from captured electromagnetic waves. Additionally, some countermeasures are investigated to avoid the problem.

  20. Leakage detection device for weld portion

    Energy Technology Data Exchange (ETDEWEB)

    Shinkawa, Toshio; Setokuchi, Sadayuki.

    1994-02-04

    The present invention concerns leakage detection device for weld portions, for example, in a nuclear reactor cavity, which can rapidly detect by remote control. That is, a detection device capable of self running and stopping on a guide rail along a weld line is disposed. The detection device comprises a coating mechanism for automatically coating soap water to the weld portion, a vacuum box capable of evacuating the coated surface and a camera for detecting the presence or absence of the soap bubbles generated under the evacuation. Such a device can conduct, by remote control, self running/stopping along with the weld line, coating of the soap water, settling of the vacuum box and confirmation and recording of foaming by using a television monitor. Accordingly, leakage in the weld portion in the reactor cavity or the like can be inspected. As a result, it greatly contributes to improvement of danger upon worker's operation at high place, detection accuracy and reliability of detection and shortening of operation period. (I.S.).

  1. Residential Forced Air System Cabinet Leakage and Blower Performance

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain S.; Dickerhoff, Darryl J.; Delp, William W.

    2010-03-01

    This project evaluated the air leakage and electric power consumption of Residential HVAC components, with a particular focus on air leakage of furnace cabinets. Laboratory testing of HVAC components indicated that air leakage can be significant and highly variable from unit to unit ? indicating the need for a standard test method and specifying maximum allowable air leakage in California State energy codes. To further this effort, this project provided technical assistance for the development of a national standard for Residential HVAC equipment air leakage. This standard is being developed by ASHRAE and is called"ASHRAE Standard 193P - Method of test for Determining the Air Leakage Rate of HVAC Equipment". The final part of this project evaluated techniques for measurement of furnace blower power consumption. A draft test procedure for power consumption was developed in collaboration with the Canadian General Standards Board: CSA 823"Performance Standard for air handlers in residential space conditioning systems".

  2. Leakage detection in earth dams by heated fiber optics

    Energy Technology Data Exchange (ETDEWEB)

    Beck, Y.L.; Clerc, T.L.; Fabre, J.P.; Fry, J.J. [EDF, Grenoble (France); Royet, P. [CEMAGREF, Aix-en-Provence (France)

    2010-07-01

    Leakage detection is a major key to ensuring dam safety. Thermal methods based on distributed temperature measurement by means of fibre optics are currently among the most effective and promising means for identifying internal erosion processes. This paper investigated leakage detection in earth dams by use of heated fibre optics. After a description of the active method for leakage detection, the paper presented the validation of this detection method on a controlled experimental dike, the upstream drainage system of which was instrumented with fibre optics and where leakages were artificially provoked as well as on some real sites. The leakages were successfully located at both sites. The capability of the proposed method to estimate flow rates was demonstrated for the experimental basin. It was found that thermal monitoring by distributed measurements along bier optics is a powerful tool for detecting leakages in dikes.

  3. Distributed public key schemes secure against continual leakage

    DEFF Research Database (Denmark)

    Akavia, Adi; Goldwasser, Shafi; Hazay, Carmit

    2012-01-01

    In this work we study distributed public key schemes secure against continual memory leakage. The secret key will be shared among two computing devices communicating over a public channel, and the decryption operation will be computed by a simple 2-party protocol between the devices. Similarly...... against continual memory leakage, under the Bilinear Decisional Diffie-Hellman and $2$-linear assumptions. Our schemes have the following properties: 1. Our DPKE and DIBE schemes tolerate leakage at all times, including during refresh. During refresh the tolerated leakage is a (1/2-o (1),1)-fraction...... of the secret memory of P1, P2 respectively; and at all other times (post key generation) the tolerated leakage is a (1-o (1),1)-fraction of the secret memory of P1, P2 respectively. Our DIBE scheme tolerates leakage from both the master secret key and the identity based secret keys. Our DPKE scheme is CCA2...

  4. Transanal stent in anterior resection does not prevent anastomotic leakage

    DEFF Research Database (Denmark)

    Bülow, Steffen; Bulut, O; Christensen, Ib Jarle;

    2006-01-01

    OBJECTIVE: A defunctioning transanal stent may theoretically reduce the leakage rate after anterior rectal resection. We present a randomized open study with the aim of comparing the leakage rate after anterior resection with a loop ileostomy, a transanal stent, both or neither. PATIENTS AND METH....... On this basis it was decided to discontinue the study prematurely for ethical reasons. CONCLUSION: Decompression of the anastomosis with a transanal stent does not reduce the risk of anastomotic leakage after anterior resection....

  5. Leakage Test Criteria for Subsea Christmas Tree Valves

    OpenAIRE

    Alstad, Charlotte

    2011-01-01

    This Master`s Thesis deal with integrity and barrier philosophy. A special focus has been on internal leakage through barrier elements. There is an increasing discussion about what a primary and secondary barrier is, how many barriers there should be, their permitted internal leakage acceptance criteria and their integrity. Subsea Christmas tree (XMT) is considered as a pressure barrier element in subsea production systems. Rules and regulations require frequent leakage testing of subsea XMT ...

  6. Changing the warm-up transition of macromolecular system at irradiation

    International Nuclear Information System (INIS)

    Full text: The whole complex of characteristics of macromolecular system is defined by its warm-up condition. So for revealing a consequence of irradiating it is necessary study of warm-up turning the molecules of chain construction from the energy of irradiation. As is well known an irradiation is accompanied by suturing or destruction of separate kinetic units. In given work is studied changing a warm-up interval of high-elastic state of macromolecular system depending on energy of irradiating for the reason extrapolation its results to deciding the applied problems of ecological, metabolically processes. Coming from theories free volume and Boltzmann's distribution were determined changing the temperatures of glassing and viscous current. The variable parameter considered models is a mobility factor, which is defined as an attitude radiation energy to energy of Van-der-Waals interactions and hydrogen bonds, where energy of irradiation is taken much less, than energy of chemical bond. Restriction of energy of inter- and intramolecular chemical unbound kinetic units guarantees wholeness of the macromolecular chains that it is required for functional quality conservations. The obtained results show that than more deflection of mobility factor from units, that broader area high-elastic considered model of macromolecular system. Changing a warm-up interval also enough vastly depends on the free member of deciding, which characterizes a condition of polymer before the irradiation. Rendered that the most vulnerable to irradiating is hard chain macromolecular system

  7. Control of rf leakage in the TRIUMF cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Dohan, D.; Fong, K.; Pacak, V.

    1986-10-01

    The TRIUMF vacuum chamber and beam gap form a cavity with resonant rf modes close to the operating frequency. The resultant leakage into this beam cavity poses significant problems to beam diagnostic equipment and can damage non-cooled components in this volume. Model studies, machine measurements and theoretical calculations have been carried out in order to understand and control the leakage. The amount of this rf leakage is shown to depend critically on the alignment at the dee gap. Two dominant leakage modes have been identified and their excitation mechanisms have been studied. The total leakage field depends critically on the amplitudes and phases of these parasitic modes. Through suitable superposition of these modes, the leakage can be reduced and its pattern modified by the realignment of the top and bottom ground arm tips. Reductions in the leakage by 10 to 15 dB have been achieved on the model and on the machine. The major cause of heating of the resonator strongbacks has been found to be due not to the leakage currents themselves, but to multipactoring effects in the beam cavity driven by leakage electric fields.

  8. Vertebroplasty: Magnetic Resonance Findings Related to Cement Leakage Risk

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Y.H.; Han, D.; Cha, J.H.; Seong, C.K.; Kim, J.; Choi, Y.H. [Dept. of Radiology, Seoul Municipal Boramae Hospital, Seoul (Korea, republic of)

    2007-04-15

    Purpose: To find magnetic resonance (MR) findings predicting cement leakage in patients receiving percutaneous vertebroplasty (PVP) due to osteoporotic compression fractures. Material and Methods: MR was done in 43 patients (age 52-89 years) before PVP (56 vertebrae), which was done via a bipedicular approach with fluoroscopic monitoring. Shortly after the procedure, a non-contrast-enhanced computed tomography (CT) scan was done at the vertebroplasty sites for evaluation of bone cement leakage. The following MR findings of fractured vertebral bodies were retrospectively reviewed for correlation with leakage risk: severity of bone-marrow edema, presence of a T2-weighted low-signal-intensity line, percentage residual vertebral body height, presence of either a vacuum or cystic change within the vertebral body, and presence of a cortical disruption. Results: After PVP, cement leakage was detected in 35 vertebrae (62.5%). Leakage was most frequently observed in the anterior external vertebral venous plexus (46%). Cement leakage rate increased when there was a cortical disruption (P = 0.037), especially at the endplates, while it decreased when there was a vacuum or a cystic change within the fractured vertebra (P 0.019). Other MR findings were not related to the risk of cement leakage. Conclusion: The risk of cement leakage in PVP increases when MR shows cortical disruption in a fractured vertebral body, especially at the endplates. It decreases when MR shows a vacuum or cystic change within the body. Keywords Cement leakage, MR imaging, spine, vertebroplasty.

  9. Influence of Slot Defect Length on Magnetic Flux Leakage

    Institute of Scientific and Technical Information of China (English)

    Songling HUANG; Luming LI; Haiqing YANG; Keren SHI

    2004-01-01

    A key issue, which influences the applications of magnetic flux leakage testing, is defect quantification. There have been many research on the relationship between width, depth and magnetic flux leakage of slot defect. However, the length factor is often ignored. The relationship between characteristics of defect leakage field and defect length was investigated. The magnetic flux leakages of a series of plate specimens with the same width, same depth and different length slot defects were tested under the same magnetizing conditions. Testing results show that defect length is an important parameter needed to consider in quantifying defects.

  10. Leakage of high active liquid waste into the thermowell of HALW evaporator (4/4). Repair work for leakage prevention

    International Nuclear Information System (INIS)

    Leakage of high active liquid waste into the thermowell of High Active Liquid Waste (HALW) Evaporator was confirmed when thermometers were replaced in Rokkasho Reprocessing Plant. We estimate that the cause of the leakage is tunnel corrosion at the bottom cap of the thermowell due to high temperature at the bottom of the evaporator. This paper deals with the repair work for the leakage prevention. (author)

  11. Leakages and pressure relations: an experimental research

    Directory of Open Access Journals (Sweden)

    F. De Paola

    2012-07-01

    Full Text Available Leaks in water systems are presently a frequent and increasing event that involves cost increase and poor service, not compliant to quality standards and modern management criteria. The most recent data available in Italy, resumed into the report issued by Control Committee for Water Resources Use (CONVIRI, shows leakages with an average value of 37%. It is important, for maintenance perspective, to investigate occurrence and evolution of water leaks and the analytical links between leaks Qp and network pressure P, for a reliable calibration of water networks quali-quantitative simulation models. The present work reports the results of an experimental campaign started at Laboratory of Hydraulic of Department of Hydraulic, Geotechnical and Environmental Engineering of University of Naples Federico II in order to analyze the features of Qp (P relation, which are compared with principal results issued in literature.

  12. Leakages and pressure relation: an experimental research

    Directory of Open Access Journals (Sweden)

    F. De Paola

    2012-11-01

    Full Text Available Leaks in water systems are presently a frequent and increasing event that involves cost increase and poor service, not compliant to quality standards and modern management criteria. The most recent data available in Italy, resumed into the report issued by Control Committee for Water Resources Use (CONVIRI, shows leakages with an average value of 37%. It is therefore important, for maintenance perspective, to investigate occurrence and evolution of water leaks and the analytical link between leaks Qp and network pressure P, for a reliable calibration of water networks quali-quantitative simulation models. The present work reports the first results of an experimental campaign started at Laboratory of Hydraulics of Department of Hydraulics, Geotechnical and Environmental Engineering of University of Naples Federico II in order to analyze the features of Qp(P relation, which are compared with other results issued in literature.

  13. Anomaly detection using magnetic flux leakage technology

    Energy Technology Data Exchange (ETDEWEB)

    Rempel, Raymond G. [BJ Pipeline Inspection Services, Alberta (Canada)

    2005-07-01

    There are many aspects to properly assessing the integrity of a pipeline. In-line-Inspection (ILI) tools, in particular those that employ the advanced use of Magnetic Flux Leakage (MFL) technology, provide a valuable means of achieving required up-to-date knowledge of a pipeline. More prevalent use of High Resolution MFL In-Line-Inspection tools is growing the knowledge base that leads to more reliable and accurate identification of anomalies in a pipeline, thus, minimizing the need for expensive verification excavations. Accurate assessment of pipeline anomalies can improve the decision making process within an Integrity Management Program and excavation programs can then focus on required repairs instead of calibration or exploratory digs. Utilizing the information from an MFL ILI inspection is not only cost effective but, as well, can also prove to be an extremely valuable building block of a Pipeline Integrity Management Program. (author)

  14. Leakage tests on the EURATOM LCT coil

    International Nuclear Information System (INIS)

    The acceptance tests at ambient temperature on the superconducting LCT coil, which was developed and manufactured by Siemens, were successful. The size and complexity of the coil imposed high demands on in-process quality control. The helium leakage tests and integrity of the test procedures were particularly important. Leaks were detected at an early stage by means of inspection and test plans and were repaired at no great expense. Unsuitable components were detected by routine tests on critical parts, such as belows, current feed-throughs and potential separators under simulated operating conditions (cycles up to 4 K and 24 bar). The procedure for checking for helium leaks was selected such that the permissible leak rate could be proved within the minimum possible time. 500 m hollow conductors were tested using a specially developed procedure. Over 500 individual inspections and tests were performed using more than 20 different test set-ups. (orig.)

  15. Synthesis and characterization of miktoarm star copolymer of styrene and butadiene using multifunctional macromolecular initiator

    Institute of Scientific and Technical Information of China (English)

    Hai Yan Zhang; Xing Ying Zhang

    2009-01-01

    A new kind of multifunctional macromolecular initiator with Sn-C bonds and polydiene arms was synthesized by living anionic polymerization.At first,polydiene-stannum chloride(PD-SnCl3)was prepared by the reaction of n-butyl-Li(n-BuLi),stannic chloride(SnCl4)and diene.Then PD-SnCl3 was used to react with the dilithium initiator to prepare the multifunctional organic macromolecular initiators.The result suggested that the initiators had a remarkable yield by GPC,nearly 90%.By using these multifunctional macromolecular initiators,styrene and butadiene were effectively polymerized via anionic polymerization,which gave birth to novel miktoarm star copolymers.The relative molecular weight and polydispersity index,microstructure contents,copolymerization components,glass transition temperature(Tg)and morphology of the miktoarm star copolymers were investigated by GPC-UV,1H NMR,DSC and TEM,respectively.

  16. Use of Site-Specifically Tethered Chemical Nucleases to Study Macromolecular Reactions

    Directory of Open Access Journals (Sweden)

    Mukherjee Srabani

    2003-01-01

    Full Text Available During a complex macromolecular reaction multiple changes in molecular conformation and interactions with ligands may occur. X-ray crystallography may provide only a limited set of snapshots of these changes. Solution methods can augment such structural information to provide a more complete picture of a macromolecular reaction. We analyzed the changes in protein conformation and protein:nucleic acid interactions which occur during transcription initiation by using a chemical nuclease tethered to cysteines introduced site-specifically into the RNA polymerase of bacteriophage T7 (T7 RNAP. Changes in cleavage patterns as the polymerase steps through transcription reveal a series of structural transitions which mediate transcription initiation. Cleavage by tethered chemical nucleases is seen to be a powerful method for revealing the conformational dynamics of macromolecular reactions, and has certain advantages over cross-linking or energy transfer approaches.

  17. New Paradigm for Macromolecular Crystallography Experiments at SSRL: Automated Crystal Screening And Remote Data Collection

    Energy Technology Data Exchange (ETDEWEB)

    Soltis, S.M.; Cohen, A.E.; Deacon, A.; Eriksson, T.; Gonzalez, A.; McPhillips, S.; Chui, H.; Dunten, P.; Hollenbeck, M.; Mathews, I.; Miller, M.; Moorhead, P.; Phizackerley, R.P.; Smith, C.; Song, J.; Bedem, H.van dem; Ellis, P.; Kuhn, P.; McPhillips, T.; Sauter, N.; Sharp, K.

    2009-05-26

    Complete automation of the macromolecular crystallography experiment has been achieved at Stanford Synchrotron Radiation Lightsource (SSRL) through the combination of robust mechanized experimental hardware and a flexible control system with an intuitive user interface. These highly reliable systems have enabled crystallography experiments to be carried out from the researchers' home institutions and other remote locations while retaining complete control over even the most challenging systems. A breakthrough component of the system, the Stanford Auto-Mounter (SAM), has enabled the efficient mounting of cryocooled samples without human intervention. Taking advantage of this automation, researchers have successfully screened more than 200 000 samples to select the crystals with the best diffraction quality for data collection as well as to determine optimal crystallization and cryocooling conditions. These systems, which have been deployed on all SSRL macromolecular crystallography beamlines and several beamlines worldwide, are used by more than 80 research groups in remote locations, establishing a new paradigm for macromolecular crystallography experimentation.

  18. Effect of macromolecular crowding on the rate of diffusion-limited enzymatic reaction

    Indian Academy of Sciences (India)

    Manish Agrawal; S B Santra; Rajat Anand; Rajaram Swaminathan

    2008-08-01

    The cytoplasm of a living cell is crowded with several macromolecules of different shapes and sizes. Molecular diffusion in such a medium becomes anomalous due to the presence of macromolecules and diffusivity is expected to decrease with increase in macromolecular crowding. Moreover, many cellular processes are dependent on molecular diffusion in the cell cytosol. The enzymatic reaction rate has been shown to be affected by the presence of such macromolecules. A simple numerical model is proposed here based on percolation and diffusion in disordered systems to study the effect of macromolecular crowding on the enzymatic reaction rates. The model qualitatively explains some of the experimental observations.

  19. Accounting for Large Amplitude Protein Deformation during in Silico Macromolecular Docking

    Directory of Open Access Journals (Sweden)

    Chantal Prévost

    2011-02-01

    Full Text Available Rapid progress of theoretical methods and computer calculation resources has turned in silico methods into a conceivable tool to predict the 3D structure of macromolecular assemblages, starting from the structure of their separate elements. Still, some classes of complexes represent a real challenge for macromolecular docking methods. In these complexes, protein parts like loops or domains undergo large amplitude deformations upon association, thus remodeling the surface accessible to the partner protein or DNA.We discuss the problems linked with managing such rearrangements in docking methods and we review strategies that are presently being explored, as well as their limitations and success.

  20. Accounting for large amplitude protein deformation during in silico macromolecular docking.

    Science.gov (United States)

    Bastard, Karine; Saladin, Adrien; Prévost, Chantal

    2011-02-22

    Rapid progress of theoretical methods and computer calculation resources has turned in silico methods into a conceivable tool to predict the 3D structure of macromolecular assemblages, starting from the structure of their separate elements. Still, some classes of complexes represent a real challenge for macromolecular docking methods. In these complexes, protein parts like loops or domains undergo large amplitude deformations upon association, thus remodeling the surface accessible to the partner protein or DNA. We discuss the problems linked with managing such rearrangements in docking methods and we review strategies that are presently being explored, as well as their limitations and success.

  1. THE STEADY/PULSATILE FLOW AND MACROMOLECULAR TRANSPORT IN T-BIFURCATION BLOOD VESSELS

    Institute of Scientific and Technical Information of China (English)

    李丁; 温功碧

    2003-01-01

    A numerical analysis of the steady and pulsatile, macromolecular( such as lowdensity lipopotein ( LDL ), Albumin ) transport in T-bifurcation was proposed. Theinfluence of Reynolds number and mass flow ratio etc. parameters on the velocity field andmass transport were calculated. The computational results predict that the blood flow factorsaffect the macromolecular distribution and the transport across the wall, it shows thathemodynamic play an important role in the process of atherosclerosis . The LDL and Albuminconcentration on the wall varies most greatly in flow bifurcation area where the wall shearstress varies greatly at the branching vessel and the atherosclerosis often appears there.

  2. 42 CFR 84.123 - Exhalation valve leakage test.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Exhalation valve leakage test. 84.123 Section 84.123 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY....123 Exhalation valve leakage test. (a) Dry exhalation valves and valve seats will be subjected to...

  3. An observed 20 yr time-series of Agulhas leakage

    Directory of Open Access Journals (Sweden)

    D. Le Bars

    2014-01-01

    Full Text Available We provide a time series of Agulhas leakage anomalies over the last twenty years from satellite altimetry. Until now, measuring the interannual variability of Indo-Atlantic exchange has been the major barrier in the investigation of the dynamics and large scale impact of Agulhas leakage. We compute the difference of transport between Agulhas Current and Agulhas Return Current which allows to deduce Agulhas leakage. The main difficulty is to separate the Agulhas Return Current from the southern limb of the subtropical "supergyre" south of Africa. For this purpose, an algorithm that uses absolute dynamic topography data is developed. The algorithm is applied to a state-of-the-art ocean model. The comparison with a Lagrangian method to measure the leakage allows to validate the new method. An important result is that it is possible to measure Agulhas leakage in this model using the velocity field along a section that crosses both the Agulhas Current and the Agulhas Return Current. In the model a good correlation is found between measuring leakage using the full depth velocities and using only the surface geostrophic velocities. This allows us to extend the method to along-track absolute dynamic topography from satellites. It is shown that the accuracy of the mean dynamic topography does not allow to determine the mean leakage but that leakage anomalies can be accurately computed.

  4. Macrophage migration inhibitory factor induces vascular leakage via autophagy

    Directory of Open Access Journals (Sweden)

    Hong-Ru Chen

    2015-01-01

    Full Text Available Vascular leakage is an important feature of acute inflammatory shock, which currently has no effective treatment. Macrophage migration inhibitory factor (MIF is a pro-inflammatory cytokine that can induce vascular leakage and plays an important role in the pathogenesis of shock. However, the mechanism of MIF-induced vascular leakage is still unclear. In this study, using recombinant MIF (rMIF, we demonstrated that MIF induced disorganization and degradation of junction proteins and increased the permeability of human endothelial cells in vitro. Western blotting analysis showed that rMIF treatment induced LC3 conversion and p62 degradation. Inhibition of autophagy with a PI3K inhibitor (3-MA, a ROS scavenger (NAC or autophagosomal-lysosomal fusion inhibitors (bafilomycin A1 and chloroquine rescued rMIF-induced vascular leakage, suggesting that autophagy mediates MIF-induced vascular leakage. The potential involvement of other signaling pathways was also studied using different inhibitors, and the results suggested that MIF-induced vascular leakage may occur through the ERK pathway. In conclusion, we showed that MIF triggered autophagic degradation of endothelial cells, resulting in vascular leakage. Inhibition of MIF-induced autophagy may provide therapeutic targets against vascular leakage in inflammatory shock.

  5. Study on Acoustic Catheter of Boiler Tube Leakage Monitoring Systems

    Science.gov (United States)

    Lv, Yongxing; Feng, Qiang

    Boiler tube leakage is the major reason of affecting the safe operation of the unit now, there are 3 methods of the "four tube" leakage detection: Traditional method, filtering method and acoustic spectrum analysis, acoustic spectrum analysis is the common method, but this method have low sensitivity and the sensor damage easily. Therewith, designed the special acoustic catheter with acoustic resonance cavity type, proved by experiments, the acoustic catheter with acoustic resonance cavity type can enhance leakage sound, can accurately extract leakage signals, has high sensitivity, and can avoid the effect of sensor by fire and hot-gas when the furnace is in positive pressure situation, reduce the installation and maintenance costs of the boiler tube leakage monitor system.

  6. Leakage-Aware Modulo Scheduling for Embedded VLIW Processors

    Institute of Scientific and Technical Information of China (English)

    Yong Guan; Jingling Xue

    2011-01-01

    As semi-conductor technologies move down to the nanometer scale, leakage power has become a significant component of the total power consumption. In this paper, we present a leakage-aware modulo scheduling algorithm to achieve leakage energy saving for applications with loops on Very Long Instruction Word (VLIW) architectures. The proposed algorithm is designed to maximize the idleness of function units integrated with the dual-threshold domino logic, and reduce the number of transitions between the active and sleep modes. We have implemented our technique in the Trimaran compiler and conducted experiments using a set of embedded benchmarks from DSPstone and Mibench on the cycle-accurate VLIW simulator of Trimaran. The results show that our technique achieves significant leakage energy saving compared with a previously published DAG-based (Directed Acyclic Graph) leakage-aware scheduling algorithm.

  7. Using Unobtrusive Techniques for Detecting Leakage of Data

    Directory of Open Access Journals (Sweden)

    Shailaja B. Jadhav

    2013-06-01

    Full Text Available While doing business, there are situations when someimportant information or data should be handed over tosome third parties. The data important to organization mustbe secured but the third parties are not that careful aboutthe data. So there is possibility that the data gets leaked.Here in this paper we are considering the chances that thethird party is responsible for the leakage. We propose dataallocation strategies (across the agents that improvethe probability of identifying leakages. There are someavailable techniques like watermarking, perturbation used toidentifying data leakage, but those are having fewdrawbacks. So we are trying to detect the leakage by using atechnique called unobtrusive. This technique will give usresults in many prospective to find out leakage of theimportant data.

  8. Energy losses by air leakage in condensing tumble dryers

    International Nuclear Information System (INIS)

    Tumble dryers, used for the drying of textiles, consume a considerable amount of electricity due to the large number of dryers in use. A large amount of this electricity is produced from coal, making it important to reduce the electricity use and, hence, the carbon dioxide emissions. Earlier studies made on the condensing tumble dryer have pointed out that leakage is one of the parameters affecting the electricity use for the drying process. With a view to reducing the energy use, leakage was estimated through measurements and modelling. Energy balances were used in order to verify the leakage. The energy balance showed good agreement with the results from the model and confirms that the leakage out from the dryer arises mainly between the heater and the drum where the air is hot and has low relative humidity. Large leakage at this location is detrimental for the energy efficiency of the dryer, meaning that the leakage must be reduced in order to obtain a reduced energy use. Results from the model also point out that even small changes in the size of gaps, or changes to the pressure in the internal system, result in a significant change in leakage from the dryer. - Highlights: ► Energy balances and fluid mechanics modelling have been performed on a tumble dryer. ► Main leakage of drying gas was found between the heater and the drum of the dryer. ► Leakage at this location has a large impact on the energy efficiency. ► Both energy balances and modelling strengthens the assumption of leakage location.

  9. Pyelolithotomy by the use of a hydrophilous macromolecular binding material ("pyeloform" pyelotomy).

    Science.gov (United States)

    Nagy, Z; Frang, D; Jávor, A; Götz, F; Szatmári, J; Vizi, L; Kovács, G

    1984-01-01

    The use of a synthetic macromolecular hydrophilous binding material for the extraction of multiple renal calculi (" Pyeloform " pyelotomy) is reported. An account of the results of animal studies in vitro is given and the possibilities of the method in are pointed out. PMID:6724825

  10. Closed Mechanoelectrochemical Cycles of Individual Single-Chain Macromolecular Motors by AFM

    NARCIS (Netherlands)

    Shi, Weiqing; Giannotti, Marina I.; Zhang, Xi; Hempenius, Mark A.; Schönherr, Holger; Vancso, G. Julius

    2007-01-01

    Motor cycles: Mechanoelectrochemical loops of single-chain macromolecular motors based on individual end-grafted poly(ferrocenyldimethylsilane) are shown by AFM to have an efficiency of up to 26 %. Upon oxidation of a prestretched chain, the chain length increases and the force decreases significant

  11. Interplay between the bacterial nucleoid protein H-NS and macromolecular crowding in compacting DNA

    NARCIS (Netherlands)

    Wintraecken, C.H.J.M.

    2012-01-01

      In this dissertation we discuss H-NS and its connection to nucleoid compaction and organization. Nucleoid formation involves a dramatic reduction in coil volume of the genomic DNA. Four factors are thought to influence coil volume: supercoiling, DNA charge neutralization, macromolecular crow

  12. Macromolecular Crowding Modulates Folding Mechanism of α/β Protein Apoflavodoxin

    Science.gov (United States)

    Homouz, D.; Stagg, L.; Wittungstafshede, P.; Cheung, M.

    2009-01-01

    Protein dynamics in cells may be different from that in dilute solutions in vitro since the environment in cells is highly concentrated with other macromolecules. This volume exclusion due to macromolecular crowding is predicted to affect both equilibrium and kinetic processes involving protein conformational changes. To quantify macromolecular crowding effects on protein folding mechanisms, here we have investigated the folding energy landscape of an alpha/beta protein, apoflavodoxin, in the presence of inert macromolecular crowding agents using in silico and in vitro approaches. By coarse-grained molecular simulations and topology-based potential interactions, we probed the effects of increased volume fraction of crowding agents (phi_c) as well as of crowding agent geometry (sphere or spherocylinder) at high phi_c. Parallel kinetic folding experiments with purified Desulfovibro desulfuricans apoflavodoxin in vitro were performed in the presence of Ficoll (sphere) and Dextran (spherocylinder) synthetic crowding agents. In conclusion, we have identified in silico crowding conditions that best enhance protein stability and discovered that upon manipulation of the crowding conditions, folding routes experiencing topological frustrations can be either enhanced or relieved. The test-tube experiments confirmed that apoflavodoxin's time-resolved folding path is modulated by crowding agent geometry. We propose that macromolecular crowding effects may be a tool for manipulation of protein folding and function in living cells.

  13. Leakage experiences with 1 MW steam generator

    International Nuclear Information System (INIS)

    An 1 MW steam generator was tested from October, 1971 and completed with the first series of experiments by May, 1972 after 3600 hours of operation. During these tests, unextraordinary heat absorption was experienced in the downcomer region, which led to shortage of heat transfer area to attain the rated steam temperature and to one of the reasons of flow instabilities. The steam generator was disassembled to get test pieces for structure as well as material examinations and then it was reassembled to proceed the second series of tests. Before it was done, a modification was provided to insulate the downcomer region by putting a gas space around the downcomer tube. The gas space was provided by a dual tube and spacers were welded on the inner tube and an end plate was welded on upper parts between the two to seal the gap by means of fillet welding. After the modified steam generator was put into operation, water happened to leak into a sodium side two times through these additional welding spots for the gas insulation. This paper presents operating conditions and behaviors of monitors at the time of the leakages, identifications of leaked spots, an evaluation of causes and a treatment or a precaution for them

  14. Information Leakage Prevention Using Virtual Disk Drive

    Directory of Open Access Journals (Sweden)

    Tarek S. Sobh

    2013-06-01

    Full Text Available The worst news for information technology people are computer has been stolen or lost. The actual problem is the loss of the data stored on the hard drive that can fall into the wrong hands. However, users of information system and laptops computers are facing real problems with due to intruders using attack techniques when they are connected to the network and lost or stolen computers. In order to protect your organization against information leakage you should encrypt this data by only allowing the user with access to the encryption key to view the data, authorized application usage, and control who gets access to specific types of data. This work focuses on confidentiality of secure information storage. In addition, it presents the model to create of a Virtual Disk Drive (VDD on MS Windows, that appear to the user (after the mounting process as hard disks, but that are really stored as ciphered files on a file system. The proposed VDD prevents dictionary attacks and brute force attacks by incorporating a CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart in the login mechanism. The authentication method for the VDD login is based upon a 3-D image CAPTCHA. All components of this work are integrated in one security VDD tool called "SecDisk".

  15. Leakage-Resilient Cryptography from the Inner-Product Extractor

    DEFF Research Database (Denmark)

    Dziembowski, Stefan; Faust, Sebastian

    2011-01-01

    We present a generic method to secure various widely-used cryptosystems against arbitrary side-channel leakage, as long as the leakage adheres three restrictions: first, it is bounded per observation but in total can be arbitrary large. Second, memory parts leak independently, and, third, the ran......We present a generic method to secure various widely-used cryptosystems against arbitrary side-channel leakage, as long as the leakage adheres three restrictions: first, it is bounded per observation but in total can be arbitrary large. Second, memory parts leak independently, and, third......, we use a randomized encoding and develop a method to securely refresh these encodings even in the presence of leakage. We then show that our encoding scheme exhibits an efficient additive homomorphism which can be used to protect important cryptographic tasks such as identification, signing...... and encryption. More precisely, we propose efficient implementations of the Okamoto identification scheme, and of an ElGamal-based cryptosystem with security against continuous leakage, as long as the leakage adheres the above mentioned restrictions. We prove security of the Okamoto scheme under the DL...

  16. Novel Sleep Transistor Techniques for Low Leakage Power Peripheral Circuits

    Directory of Open Access Journals (Sweden)

    Rajani H.P

    2012-09-01

    Full Text Available Static power consumption is a major concern in nanometre technologies. Along with technology scaling down and higher operating speeds of CMOS VLSI circuits, the leakage power is getting enhanced. As process geometries are becoming smaller, device density increases and threshold voltage as well as oxide thickness decrease to keep pace with performance. Two novel circuit techniques for leakage current reduction in inverters with and without state retention property are presented in this work. The powerdissipation during inactive (standby mode of operation can be significantly reduced compared to traditional power gating methods by these circuit techniques. The proposed circuit techniques are applied to inverters and the results are compared with earlier inverter leakage minimization techniques. Inverter buffer chains are designed using new state retention low leakage technique and found to be dissipatinglower power with state retention. All low leakage inverters are designed and simulated in cadence design environment using 90 nm technology files. The leakage power during sleep mode is found to be better by X 63 times for novel method. The total power dissipation has also reduced by a factor of X 3.5, compared to earlier sleepy keeper technique. The state retention feature is also good compared to earlier leakage power reduction methodologies.

  17. Novel Sleep Transistor Techniques for Low Leakage Power Peripheral Circuits

    Directory of Open Access Journals (Sweden)

    Rajani H.P

    2012-08-01

    Full Text Available Static power consumption is a major concern in nanometre technologies. Along with technology scaling down and higher operating speeds of CMOS VLSI circuits, the leakage power is getting enhanced. As process geometries are becoming smaller, device density increases and threshold voltage as well as oxide thickness decrease to keep pace with performance. Two novel circuit techniques for leakage current reduction in inverters with and without state retention property are presented in this work. The power dissipation during inactive (standby mode of operation can be significantly reduced compared to traditional power gating methods by these circuit techniques. The proposed circuit techniques are applied to inverters and the results are compared with earlier inverter leakage minimization techniques. Inverter buffer chains are designed using new state retention low leakage technique and found to be dissipating lower power with state retention. All low leakage inverters are designed and simulated in cadence design environment using 90 nm technology files. The leakage power during sleep mode is found to be better by X 63 times for novel method. The total power dissipation has also reduced by a factor of X 3.5, compared to earlier sleepy keeper technique. The state retention feature is also good compared to earlier leakage power reduction methodologies.

  18. Influence of specimen velocity on the leakage signal in magnetic flux leakage type nondestructive testing

    CERN Document Server

    Zhang, Lintao; Cameron, Ian; Sienz, Johann; Boat, Matthew; Pearson, Neil

    2015-01-01

    We investigate the influence of the specimen velocity on the magnetic flux leakage with the aim of selecting the optimum sensor locations. Parametric numerical simulations where the specimen velocity was in the range [0.1-20] m$\\cdot$s$^{-1}$ were carried out. As the specimen velocity is increased, the magnetic field varies from being symmetrical to being asymmetric. For the radial magnetic induction, the peak to peak value moves from the centre of the bridge towards the direction of the specimen movement. For the axial magnetic induction, the specimen velocity influence is dependent on the sensor location and a signal-velocity independent region was discussed.

  19. Theory and Practice of a Leakage Resilient Masking Scheme

    DEFF Research Database (Denmark)

    Balasch, Josep; Faust, Sebastian; Gierlichs, Benedikt;

    2012-01-01

    A recent trend in cryptography is to formally prove the leakage resilience of cryptographic implementations – that is, one formally shows that a scheme remains provably secure even in the presence of side channel leakage. Although many of the proposed schemes are secure in a surprisingly strong...... model, most of them are unfortunately rather inefficient and come without practical security evaluations nor implementation attempts. In this work, we take a further step towards closing the gap between theoretical leakage resilient cryptography and more practice-oriented research. In particular, we...

  20. Bruce 'A' Unit 4 fuel channel feeder coupling leakage

    International Nuclear Information System (INIS)

    CANDU reactor fuel channels are connected to the primary heat transport system by mechanical joints known as feeder couplings. In 1991, three feeder coupling leakages were discovered in Bruce 4. These leakages required the unit to be shut down for repair. An investigation showed that the leakage was caused by a small 'separation' at the couplings. The assessment was that this was unlikely to be a generic issue, because the later reactors have stronger capscrews. At the time of the conference, further improvements were being considered for the seal ring and capscrew materials, and more accurate capscrew preload measurements. 3 tabs., 10 figs

  1. Flexibility damps macromolecular crowding effects on protein folding dynamics: Application to the murine prion protein (121-231)

    Science.gov (United States)

    Bergasa-Caceres, Fernando; Rabitz, Herschel A.

    2014-01-01

    A model of protein folding kinetics is applied to study the combined effects of protein flexibility and macromolecular crowding on protein folding rate and stability. It is found that the increase in stability and folding rate promoted by macromolecular crowding is damped for proteins with highly flexible native structures. The model is applied to the folding dynamics of the murine prion protein (121-231). It is found that the high flexibility of the native isoform of the murine prion protein (121-231) reduces the effects of macromolecular crowding on its folding dynamics. The relevance of these findings for the pathogenic mechanism are discussed.

  2. Transanal stent in anterior resection does not prevent anastomotic leakage

    DEFF Research Database (Denmark)

    Bülow, Steffen; Bulut, O; Christensen, Ib Jarle;

    2006-01-01

    OBJECTIVE: A defunctioning transanal stent may theoretically reduce the leakage rate after anterior rectal resection. We present a randomized open study with the aim of comparing the leakage rate after anterior resection with a loop ileostomy, a transanal stent, both or neither. PATIENTS...... completion of the operation the patients were randomized in two groups with and without a transanal stent. RESULTS: A clinically significant leakage was diagnosed in 25 patients (13%). No significant difference was found 17 of 98 patients with a stent and 8 of 96 without (P = 0.09), or in 9 of 44 ileostomy...... patients with a stent and in 3 of 45 without (P = 0.07). Several leaks over a short time led to an interim analysis after inclusion of 194 of 448 planned patients. The analysis showed no significant protective effect of the stent, and more leakages in the stent group, although not statistically significant...

  3. Competitiveness and carbon leakages in industry under asymmetric climate policy

    International Nuclear Information System (INIS)

    This research aims at studying how to predict competitiveness loss for an industry submitted to an asymmetric carbon constraint, and carbon leakages, whether high losses and important leakages might be feared, and which policies can be used to mitigate these losses and escapes. The author analyses and comments the content of four articles dealing with: the impact on competitiveness, revenue distribution and economic efficiency of a change in the allocation rules for EU greenhouse gas allowances; the relationship between allocation of CO2 allowances and competitiveness in the case of the European iron and steel industry; CO2 abatement, competitiveness and leakage in the European cement industry under EU ETS; and leakage from climate policies and border tax adjustment (lessons from a geographic model of the cement industry). Then, the author combines several approaches to study the cement and steel industries

  4. Numerical simulation of piston leakage over hermetic reciprocating compressors behavior.

    OpenAIRE

    Rigola Serrano, Joaquim; Pérez Segarra, Carlos David; Oliva Llena, Asensio

    2009-01-01

    Instantaneous flow leakage between piston and cylinder is numerically evaluated. Reynolds equation is solved to calculate the pressure leakage distribution through the piston in the compressor. Piston movement inside the cylinder is simulated from kinematic analysis of the connecting rod mechanical system and the respective force balances. An updated version of this model is here presented for different working range compressors and fluid refrigerants compressor chamber pressures distribution...

  5. Leakage Power Reduction for Battery-Operated Portable Systems

    OpenAIRE

    Yasuura, Hiroto

    2003-01-01

    This paper addresses bitwidth optimization focusing on leakage power reduction for system-level low-power design. By means of tuning the design parameter, bitwidth tailored to a given application requirements, the datapath width of processors and size of memories are optimized resulting in significant leakage power reduction besides dynamic power reduction. Experimental results for several real embedded applications, show power reduction without performance penalty range from about 21.5% to 6...

  6. Reducing Dynamic Power and Leakage Power for Embedded Systems

    OpenAIRE

    Yasuura, Hiroto

    2002-01-01

    This paper presents a system-level technique for embedded processor-based systems targeting both dynamic power and leakage power reduction using datapath width optimization. By means of tuning the design parameter, datapath width tailored to a given application requirements, the processors and memories are optimized resulting in significant power reduction, not only for dynamic power but also for leakage power. In our experiments for several real embedded applications, power reduction without...

  7. Novel Sleep Transistor Techniques for Low Leakage Power Peripheral Circuits

    OpenAIRE

    Rajani H.P; Srimannarayan Kulkarni

    2012-01-01

    Static power consumption is a major concern in nanometre technologies. Along with technology scaling down and higher operating speeds of CMOS VLSI circuits, the leakage power is getting enhanced. As process geometries are becoming smaller, device density increases and threshold voltage as well as oxide thickness decrease to keep pace with performance. Two novel circuit techniques for leakage current reduction in inverters with and without state retention property are presented in this work. T...

  8. The economic sustainability of tourism growth through leakage calculation

    OpenAIRE

    Garrigós Simón, Fernando José; Galdón Salvador, José Luis; Gil Pechuán, Ignacio

    2015-01-01

    The development and growth of tourism depend on its sustainability over time and on its benefits for destinations as a whole. However, calculating sustainability is not an easy task. This article focuses on the economic sustainability of tourism growth and, after an exhaustive review of the literature, proposes a quantitative mathematical model to measure it by analysing and calculating leakage in the hotel sector. Leakage analyses the amount of revenue generated by tourists that does not rem...

  9. CHINA LEADS IN MAGNETIC FLUX LEAKAGE TECHNOLOGY IN THE WORLD

    Institute of Scientific and Technical Information of China (English)

    Yang Jinghan

    2005-01-01

    @@ High-resolution pipeline magnetic flux leakage tool with a diameter of 1,016 millimeters, a nondestructive detector developed corporately by Pipeline Technology Co. of China Oil & Gas Pipeline Bureau (CNPTC) and British Advantica (AT), has successfully passed pulling test in Langfang Test Center of Intellectual Pipeline Detector on July 2. This indicates that China's highresolution pipeline magnetic flux leakage technology has reached international advanced level.

  10. International Market Leakage from China’s Forestry Policies

    Directory of Open Access Journals (Sweden)

    Xin Hu

    2014-11-01

    Full Text Available Carbon leakage can be a problem when seeking to reduce carbon emissions through forest policy. International market leakage is mainly caused by supply and demand imbalances in the timber market. This paper selects China, which is implementing forestry policy changes, as the research object. We begin by offering a brief analysis of China’s forestry policy changes, such as the logging quota and Six Key Forestry Programs to determine whether those policies affect timber supply. Second, through the use of three shock variables, carbon leakage is simulated under different scenarios by the Global Trade Analysis Project (GTAP model. The results reveal that the magnitude of leakage caused by implementing China’s forestry policies is between 79.7% and 88.8% with carbon leakage mainly displaced to Russia, Southeast Asia, and the EU. Two effective scenarios for reducing market leakage are presented: forest tenure reform and fast growing forest projects to improve domestic timber production, and raising tariffs on timber imports to reduce imports.

  11. Leakage Power Reduction and Analysis of CMOS Sequential Circuits

    Directory of Open Access Journals (Sweden)

    M. Janaki Rani

    2012-02-01

    Full Text Available A significant portion of the total power consumption in high performance digital circuits in deep sub micron regime is mainly due to leakage power. Leakage is the only source of power consumption in an idle circuit. Therefore it is important to reduce leakage power in portable systems. In this paper two techniques such as transistor stacking and self-adjustable voltage level circuit for reducing leakage power in sequential circuits are proposed. This work analyses the power and delay of three different types of D flip-flops using pass transistors, transmission gates and gate diffusion input gates. . All the circuits are simulated with and without the application of leakage reduction techniques. Simulation results show that the proposed pass transistor based D flip-flop using self-adjustable voltage level circuit has the least leakage power dissipation of 9.13nW with a delay of 77 nS. The circuits are simulated with MOSFET models of level 54 using HSPICE in 90 nm process technology.

  12. Acute Alcohol Intoxication-Induced Microvascular Leakage

    Science.gov (United States)

    Doggett, Travis M.; Breslin, Jerome W.

    2014-01-01

    Background Alcohol intoxication can increase inflammation and worsen injury, yet the mechanisms involved are not clear. We investigated whether acute alcohol intoxication elevates microvascular permeability, and investigated potential signaling mechanisms in endothelial cells that may be involved. Methods Conscious rats received a 2.5 g/kg alcohol bolus via gastric catheters to produce acute intoxication. Microvascular leakage of intravenously administered FITC-albumin from the mesenteric microcirculation was assessed by intravital microscopy. Endothelial-specific mechanisms were studied using cultured endothelial cell monolayers. Transendothelial electrical resistance (TER) served as an index of barrier function, before and after treatment with alcohol or its metabolite acetaldehyde. Pharmacologic agents were used to test the roles of alcohol metabolism, oxidative stress, p38 mitogen-activated protein (MAP) kinase, myosin light chain kinase (MLCK), rho kinase (ROCK), and exchange protein activated by cAMP (Epac). VE-cadherin localization was investigated to assess junctional integrity. Rac1 and RhoA activation were assessed by ELISA assays. Results Alcohol significantly increased FITC-albumin extravasation from the mesenteric microcirculation. Alcohol also significantly decreased TER and disrupted VE-cadherin organization at junctions. Acetaldehyde significantly decreased TER, but inhibition of ADH or application of a superoxide dismutase mimetic failed to prevent alcohol-induced decreases in TER. Inhibition of p38 MAP kinase, but not MLCK or ROCK, significantly attenuated the alcohol-induced barrier dysfunction. Alcohol rapidly decreased GTP-bound Rac1 but not RhoA during the drop in TER. Activation of Epac increased TER, but did not prevent alcohol from decreasing TER. However, activation of Epac after initiation of alcohol-induced barrier dysfunction quickly resolved TER to baseline levels. Conclusions Our results suggest that alcohol intoxication increases

  13. Copper Ion as a New Leakage Tracer

    Directory of Open Access Journals (Sweden)

    Modaresi J.

    2013-12-01

    Full Text Available Statement of Problem: Most failures of root canal treatments are caused by bacteria. Studies showed that the most common cause of endodontic failures were the incomplete obturation of the root canal and the lack of adequate apical seal. Some in-vitro methods are used to estimate sealing quality, generally by measuring microleakage that allows the tracer agent to penetrate the filled canal.Purpose: Conventional methods of evaluating the seal of endodontically treated teeth are complicated and have some drawbacks. We used copper ion diffusion method to assess the leakage and the results were compared to dye penetration method.Materials and Method: The crowns of 21 extracted teeth were cut off at the CEJ level. After preparing the canals, the teeth were placed in tubes containing saline. They were divided randomly into 15 experimental cases; 3 positive and 3 negative controls. Positive controls were filled by single cone without sealer while the experimental and the negative control groups were filled by lateral technique. The coronal portion of gutta was removed and 9mm was left. The external surface of each tooth was coated with nail polish. Two millimeters of apical portion was immersed into 9ml of distilled water and 0.3ml of CuSO4 solution was injected into the coronal portion. After 2 days, copper sulfate was measured by an atomic absorption spectrophotometer. The teeth were then immersed in 2% methylene blue for 24 hours, sectioned and the extent of dye penetration was measured by a stereomicroscope.Results: The maximum and minimum recorded copper ion concentrations for the experimental group were 18.37 and 2.87ppm respectively. The maximum and minimum recorded dye penetrations for the experimental group were 8.5 and 3.5mm respectively. The statistical analysis, adopting paired samples test, showed poor correlation between average recorded results of two methods.Conclusion: Based on our results, there was no significant correlation between

  14. Optimal cytoplasmatic density and flux balance model under macromolecular crowding effects.

    Science.gov (United States)

    Vazquez, Alexei

    2010-05-21

    Macromolecules occupy between 34% and 44% of the cell cytoplasm, about half the maximum packing density of spheres in three dimension. Yet, there is no clear understanding of what is special about this value. To address this fundamental question we investigate the effect of macromolecular crowding on cell metabolism. We develop a cell scale flux balance model capturing the main features of cell metabolism at different nutrient uptakes and macromolecular densities. Using this model we show there are two metabolic regimes at low and high nutrient uptakes. The latter regime is characterized by an optimal cytoplasmatic density where the increase of reaction rates by confinement and the decrease by diffusion slow-down balance. More important, the predicted optimal density is in the range of the experimentally determined density of Escherichia coli.

  15. (Questions)n on phloem biology. 2. Mass flow, molecular hopping, distribution patterns and macromolecular signalling.

    Science.gov (United States)

    van Bel, Aart J E; Furch, Alexandra C U; Hafke, Jens B; Knoblauch, Michael; Patrick, John W

    2011-10-01

    This review speculates on correlations between mass flow in sieve tubes and the distribution of photoassimilates and macromolecular signals. Since micro- (low-molecular compounds) and macromolecules are withdrawn from, and released into, the sieve-tube sap at various rates, distribution patterns of these compounds do not strictly obey mass-flow predictions. Due to serial release and retrieval transport steps executed by sieve tube plasma membranes, micromolecules are proposed to "hop" between sieve element/companion cell complexes and phloem parenchyma cells under source-limiting conditions (apoplasmic hopping). Under sink-limiting conditions, micromolecules escape from sieve tubes via pore-plasmodesma units and are temporarily stored. It is speculated that macromolecules "hop" between sieve elements and companion cells using plasmodesmal trafficking mechanisms (symplasmic hopping). We explore how differential tagging may influence distribution patterns of macromolecules and how their bidirectional movement could arise. Effects of exudation techniques on the macromolecular composition of sieve-tube sap are discussed. PMID:21889037

  16. PIMADb: A Database of Protein–Protein Interactions in Huge Macromolecular Assemblies

    Science.gov (United States)

    Mathew, Oommen K.; Sowdhamini, Ramanathan

    2016-01-01

    Protein–protein interactions play a very important role in the process of cellular functionality. Intricate details about the interactions between the proteins in a macromolecular assembly are important to understand the function and significance of protein complexes. We are reporting about a database of protein–protein interactions in huge macromolecular assemblies (PIMADb) that records the intrinsic details of 189,532 interchain interactions in 40,049 complexes from the Protein Data Bank. These details include the results of the quantification and analysis of all the interactions in the complex. The availability of interprotomer interaction networks can enable the design of point mutation experiments. PIMADb can be accessed from the URL: http://caps.ncbs.res.in/pimadb PMID:27478368

  17. Romp: The Method of Choice for Precise Macromolecular Engineering and Synthesis of Smart Materials

    Science.gov (United States)

    Khosravi, Ezat; Castle, Thomas C.; Kujawa, Margaret; Leejarkpai, Jan; Hutchings, Lian R.; Hine, Peter J.

    The recent advances in olefin metathesis highlight the impact of Ring Opening Metathesis Polymerisation (ROMP) as a powerful technique for macromolecular engineering and synthesis of smart materials with well-defined structures. ROMP has attracted a considerable research attention recently particularly by industry largely due to the development of well-defined metal complexes as initiators and also because of the award of the Noble Prize for Chemistry in 2005 to three scientists (Chauvin, Grubbs, Schrock) for their contributions in this area. This chapter discusses several interesting examples in order to demonstrate that ROMP is a power tool in macromolecular engineering and that it allows the design and synthesis of polymers with novel topologies.

  18. The macromolecular crystallography beamline I911-3 at the MAX IV laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Ursby, Thomas, E-mail: thomas.ursby@maxlab.lu.se; Unge, Johan; Appio, Roberto [Lund University, POB 118, Lund SE-221 00 (Sweden); Logan, Derek T. [Lund University, POB 124, Lund SE-221 00 (Sweden); Fredslund, Folmer; Svensson, Christer; Larsson, Krister; Labrador, Ana [Lund University, POB 118, Lund SE-221 00 (Sweden); Thunnissen, Marjolein M. G. M. [Lund University, POB 124, Lund SE-221 00 (Sweden)

    2013-07-01

    The updated macromolecular crystallography beamline I911-3 at the MAX II storage ring is described. The macromolecular crystallography beamline I911-3, part of the Cassiopeia/I911 suite of beamlines, is based on a superconducting wiggler at the MAX II ring of the MAX IV Laboratory in Lund, Sweden. The beamline is energy-tunable within a range between 6 and 18 keV. I911-3 opened for users in 2005. In 2010–2011 the experimental station was completely rebuilt and refurbished such that it has become a state-of-the-art experimental station with better possibilities for rapid throughput, crystal screening and work with smaller samples. This paper describes the complete I911-3 beamline and how it is embedded in the Cassiopeia suite of beamlines.

  19. 3DEM Loupe: Analysis of macromolecular dynamics using structures from electron microscopy.

    Science.gov (United States)

    Nogales-Cadenas, R; Jonic, S; Tama, F; Arteni, A A; Tabas-Madrid, D; Vázquez, M; Pascual-Montano, A; Sorzano, C O S

    2013-07-01

    Electron microscopy (EM) provides access to structural information of macromolecular complexes in the 3-20 Å resolution range. Normal mode analysis has been extensively used with atomic resolution structures and successfully applied to EM structures. The major application of normal modes is the identification of possible conformational changes in proteins. The analysis can throw light on the mechanism following ligand binding, protein-protein interactions, channel opening and other functional macromolecular movements. In this article, we present a new web server, 3DEM Loupe, which allows normal mode analysis of any uploaded EM volume using a user-friendly interface and an intuitive workflow. Results can be fully explored in 3D through animations and movies generated by the server. The application is freely available at http://3demloupe.cnb.csic.es.

  20. Drug-Free Macromolecular Therapeutics--A New Paradigm in Polymeric Nanomedicines.

    Science.gov (United States)

    Chu, Te-Wei; Kopeček, Jindřich

    2015-07-01

    This review highlights a unique research area in polymer-based nanomedicine designs. Drug-free macromolecular therapeutics induce apoptosis of malignant cells by the crosslinking of surface non-internalizing receptors. The receptor crosslinking is mediated by the biorecognition of high-fidelity natural binding motifs (such as antiparallel coiled-coil peptides or complementary oligonucleotides) that are grafted to the side chains of polymers or attached to targeting moieties against cell receptors. This approach features the absence of low-molecular-weight cytotoxic compounds. Here, we summarize the rationales, different designs, and advantages of drug-free macromolecular therapeutics. Recent developments of novel therapeutic systems for B-cell lymphomas are discussed, as well as relevant approaches for other diseases. We conclude by pointing out various potential future directions in this exciting new field. PMID:26191406

  1. A Nonlinear Elasticity Model of Macromolecular Conformational Change Induced by Electrostatic Forces

    OpenAIRE

    Y. C. ZHOU; Holst, Michael; McCammon, J. Andrew

    2010-01-01

    In this paper we propose a nonlinear elasticity model of macromolecular conformational change (deformation) induced by electrostatic forces generated by an implicit solvation model. The Poisson-Boltzmann equation for the electrostatic potential is analyzed in a domain varying with the elastic deformation of molecules, and a new continuous model of the electrostatic forces is developed to ensure solvability of the nonlinear elasticity equations. We derive the estimates of electrostatic forces ...

  2. Macromolecularly crowded in vitro microenvironments accelerate the production of extracellular matrix-rich supramolecular assemblies

    OpenAIRE

    Kumar, Pramod; Satyam, Abhigyan; Fan, Xingliang; Rodriguez, Brian J.; et al

    2015-01-01

    Therapeutic strategies based on the principles of tissue engineering by self-assembly put forward the notion that functional regeneration can be achieved by utilising the inherent capacity of cells to create highly sophisticated supramolecular assemblies. However, in dilute ex vivo microenvironments, prolonged culture time is required to develop an extracellular matrix-rich implantable device. Herein, we assessed the influence of macromolecular crowding, a biophysical phenomenon that regulate...

  3. From “Simple” DNA-Protein Interactions to the Macromolecular Machines of Gene Expression

    OpenAIRE

    von Hippel, Peter H.

    2007-01-01

    The physicochemical concepts that underlie our present ideas on the structure and assembly of the “macromolecular machines of gene expression” are developed, starting with the structure and folding of the individual protein and DNA components, the thermodynamics and kinetics of their conformational rearrangements during complex assembly, and the molecular basis of the sequence specificity and recognition interactions of the final assemblies that include the DNA genome. The role of diffusion i...

  4. STUDY ON HYDROLYSIS OF MACROMOLECULAR GELATIN WITH ENZYMES IN COMBINATION MODE

    Institute of Scientific and Technical Information of China (English)

    Ya-qin Huang; Rui Guan; Ming-zhi Huang

    2004-01-01

    The enzymatic hydrolysis of macromolecular gelatin with AS1.398 neutral protease, bromelain and their combinations was studied by estimating the molecular weights of their hydrolytic products. It was discovered that the products hydrolyzed by using combination enzymes had lower molecular weight than those obtained by using single ones,and the kind of enzymes, their combination mode and addition sequence are effective ways to control the molecular weights of gelatin hydrolyzates.

  5. Protein crystallography for aspiring crystallographers or how to avoid pitfalls and traps in macromolecular structure determination.

    Science.gov (United States)

    Wlodawer, Alexander; Minor, Wladek; Dauter, Zbigniew; Jaskolski, Mariusz

    2013-11-01

    The number of macromolecular structures deposited in the Protein Data Bank now approaches 100,000, with the vast majority of them determined by crystallographic methods. Thousands of papers describing such structures have been published in the scientific literature, and 20 Nobel Prizes in chemistry or medicine have been awarded for discoveries based on macromolecular crystallography. New hardware and software tools have made crystallography appear to be an almost routine (but still far from being analytical) technique and many structures are now being determined by scientists with very limited experience in the practical aspects of the field. However, this apparent ease is sometimes illusory and proper procedures need to be followed to maintain high standards of structure quality. In addition, many noncrystallographers may have problems with the critical evaluation and interpretation of structural results published in the scientific literature. The present review provides an outline of the technical aspects of crystallography for less experienced practitioners, as well as information that might be useful for users of macromolecular structures, aiming to show them how to interpret (but not overinterpret) the information present in the coordinate files and in their description. A discussion of the extent of information that can be gleaned from the atomic coordinates of structures solved at different resolution is provided, as well as problems and pitfalls encountered in structure determination and interpretation.

  6. A smooth and differentiable bulk-solvent model for macromolecular diffraction

    International Nuclear Information System (INIS)

    A new method for modeling the bulk solvent in macromolecular diffraction data based on Babinet’s principle is presented. The proposed models offer the advantage of differentiability with respect to atomic coordinates. Inclusion of low-resolution data in macromolecular crystallography requires a model for the bulk solvent. Previous methods have used a binary mask to accomplish this, which has proven to be very effective, but the mask is discontinuous at the solute–solvent boundary (i.e. the mask value jumps from zero to one) and is not differentiable with respect to atomic parameters. Here, two algorithms are introduced for computing bulk-solvent models using either a polynomial switch or a smoothly thresholded product of Gaussians, and both models are shown to be efficient and differentiable with respect to atomic coordinates. These alternative bulk-solvent models offer algorithmic improvements, while showing similar agreement of the model with the observed amplitudes relative to the binary model as monitored using R, Rfree and differences between experimental and model phases. As with the standard solvent models, the alternative models improve the agreement primarily with lower resolution (>6 Å) data versus no bulk solvent. The models are easily implemented into crystallographic software packages and can be used as a general method for bulk-solvent correction in macromolecular crystallography

  7. Principles and Overview of Sampling Methods for Modeling Macromolecular Structure and Dynamics.

    Science.gov (United States)

    Maximova, Tatiana; Moffatt, Ryan; Ma, Buyong; Nussinov, Ruth; Shehu, Amarda

    2016-04-01

    Investigation of macromolecular structure and dynamics is fundamental to understanding how macromolecules carry out their functions in the cell. Significant advances have been made toward this end in silico, with a growing number of computational methods proposed yearly to study and simulate various aspects of macromolecular structure and dynamics. This review aims to provide an overview of recent advances, focusing primarily on methods proposed for exploring the structure space of macromolecules in isolation and in assemblies for the purpose of characterizing equilibrium structure and dynamics. In addition to surveying recent applications that showcase current capabilities of computational methods, this review highlights state-of-the-art algorithmic techniques proposed to overcome challenges posed in silico by the disparate spatial and time scales accessed by dynamic macromolecules. This review is not meant to be exhaustive, as such an endeavor is impossible, but rather aims to balance breadth and depth of strategies for modeling macromolecular structure and dynamics for a broad audience of novices and experts. PMID:27124275

  8. Principles and Overview of Sampling Methods for Modeling Macromolecular Structure and Dynamics.

    Directory of Open Access Journals (Sweden)

    Tatiana Maximova

    2016-04-01

    Full Text Available Investigation of macromolecular structure and dynamics is fundamental to understanding how macromolecules carry out their functions in the cell. Significant advances have been made toward this end in silico, with a growing number of computational methods proposed yearly to study and simulate various aspects of macromolecular structure and dynamics. This review aims to provide an overview of recent advances, focusing primarily on methods proposed for exploring the structure space of macromolecules in isolation and in assemblies for the purpose of characterizing equilibrium structure and dynamics. In addition to surveying recent applications that showcase current capabilities of computational methods, this review highlights state-of-the-art algorithmic techniques proposed to overcome challenges posed in silico by the disparate spatial and time scales accessed by dynamic macromolecules. This review is not meant to be exhaustive, as such an endeavor is impossible, but rather aims to balance breadth and depth of strategies for modeling macromolecular structure and dynamics for a broad audience of novices and experts.

  9. Radio frequency leakage current from unipolar laparoscopic electrocoagulators.

    Science.gov (United States)

    DiNovo, J A

    1983-09-01

    Radio frequency (RF) leakage current has been suspected of causing accidental tissue burns associated with laparoscopic electrocoagulation used for tubal sterilization. A study was done to determine the levels of capacitively coupled RF leakage current from six unipolar laparoscopes manufactured by five companies. Leakage current values ranging from less than 100 mA to over 550 mA were measured at electrosurgical unit power settings of up to 150 w into 1,000 ohms. These levels represent 24-62% of the total electrosurgical current generated by the electrosurgical units. Using a criterion for tissue injury of 100 mA/sq cm applied for ten seconds, leakage current levels exceeding 400 mA are capable of producing burns either at the abdominal wall or to internal organs that accidentally come into contact with the body of the laparoscope. One of the six devices tested had leakage current levels higher than 400 mA at power settings lower than 100 w. Capacitance measurements between the unipolar laparoscope body and the forceps ranged from 53 to 140 picofarads.

  10. Effects of Geometry on Leakage Flow Characteristics of Brush Seal

    Institute of Scientific and Technical Information of China (English)

    Yuan Wei; Zhaobo Chen∗; Yinghou Jiao

    2015-01-01

    In order to better application of brush seal in rotating machinery, the leakage flow characteristics of the brush seal considering geometry effects are numerically analyzed using Reynolds⁃Averaged Navier⁃Stokes ( RANS) model coupling with a non⁃Darcian porous medium model. The reliability of the present numerical method is proved, which is in agreement with the experimental and numerical results from literatures. Three different bristle pack thicknesses, fence heights and initial clearances under different pressure ratios, rotational velocities and other operating conditions are utilized to investigate the effects of geometry modification on the brush seal leakage flow behaviors. It discusses the effectiveness of various geometry configurations outlining important flow features. The results indicate that the increase of fence height and clearance would lead to the increase of leakage rate. But the leakage is not linearly with respect to the bristle pack thickness, and the effect of rotational velocity is not obvious. Moreover, the detailed leakage flow fields and pressure distributions along the rotor surface, free bristle height, and fence height of the brush seals are also presented. The static pressure drop amplitude through the bristle pack and the pressure rise amplitude through the cavity would increase while the pressure differential increases. And the axial pressure is the main reason of bristle blow down. The results provide theoretical support for the brush seal structure optimal design.

  11. Report on the water leakage from instrumentation pipe in JMTR

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-03-01

    On December 10, 2002, the leakage was found at the pressure instrumentation pipe attached to the exit pipe of No.1 charging pump of the purification system of a primary cooling system at JMTR in the Oarai Research establishment, JAERI. The Investigation Committee for Water Leakage from Instrumentation Pipe in JMTR was established and organized by specialists from inside and outside JAERI on December 16 and its meeting was held in public 3 times by 6th January, 2003. They found out the cause and countermeasures of cracks, and also investigated enhancement of safety management. As the result, it was considered that the leakage started around the 6th of December 2002 and the cause of the cracks was due to fatigue by vibration of the charging pump during operation. The committee discovered following incorrect actions in the safety management. First, operation of JMTR was continued without keeping careful watch in spite of occurrence of leakage detector alarm. Second, every time when the alarm range for the reasons other than the leakage, appropriate investigation and countermeasure were not taken. Third, the manager in charge didn't have a fair understanding of the situation and didn't give an appropriate direction. This is the report on the cause and countermeasures of cracks and enhancement of safety management. (author)

  12. Understanding instrumental Stokes leakage in Murchison Widefield Array polarimetry

    Science.gov (United States)

    Sutinjo, A.; O'Sullivan, J.; Lenc, E.; Wayth, R. B.; Padhi, S.; Hall, P.; Tingay, S. J.

    2015-01-01

    This paper offers an electromagnetic, more specifically array theory, perspective on understanding strong instrumental polarization effects for planar low-frequency "aperture arrays" with the Murchison Widefield Array (MWA) as an example. A long-standing issue that has been seen here is significant instrumental Stokes leakage after calibration, particularly in Stokes Q at high frequencies. A simple model that accounts for interelement mutual coupling is presented which explains the prominence of Q leakage seen when the array is scanned away from zenith in the principal planes. On these planes, the model predicts current imbalance in the X (E-W) and Y (N-S) dipoles and hence the Q leakage. Although helpful in concept, we find that this model is inadequate to explain the full details of the observation data. This finding motivates further experimentation with more rigorous models that account for both mutual coupling and embedded element patterns. Two more rigorous models are discussed: the "full" and "average" embedded element patterns. The viability of the full model is demonstrated by simulating current MWA practice of using a Hertzian dipole model as a Jones matrix estimate. We find that these results replicate the observed Q leakage to approximately 2 to 5%. Finally, we offer more direct indication for the level of improvement expected from upgrading the Jones matrix estimate with more rigorous models. Using the average embedded pattern as an estimate for the full model, we find that Q leakage of a few percent is achievable.

  13. The Leakage Risk Monetization Model for Geologic CO2 Storage.

    Science.gov (United States)

    Bielicki, Jeffrey M; Pollak, Melisa F; Deng, Hang; Wilson, Elizabeth J; Fitts, Jeffrey P; Peters, Catherine A

    2016-05-17

    We developed the Leakage Risk Monetization Model (LRiMM) which integrates simulation of CO2 leakage from geologic CO2 storage reservoirs with estimation of monetized leakage risk (MLR). Using geospatial data, LRiMM quantifies financial responsibility if leaked CO2 or brine interferes with subsurface resources, and estimates the MLR reduction achievable by remediating leaks. We demonstrate LRiMM with simulations of 30 years of injection into the Mt. Simon sandstone at two locations that differ primarily in their proximity to existing wells that could be leakage pathways. The peak MLR for the site nearest the leakage pathways ($7.5/tCO2) was 190x larger than for the farther injection site, illustrating how careful siting would minimize MLR in heavily used sedimentary basins. Our MLR projections are at least an order of magnitude below overall CO2 storage costs at well-sited locations, but some stakeholders may incur substantial costs. Reliable methods to detect and remediate leaks could further minimize MLR. For both sites, the risk of CO2 migrating to potable aquifers or reaching the atmosphere was negligible due to secondary trapping, whereby multiple impervious sedimentary layers trap CO2 that has leaked through the primary seal of the storage formation. PMID:27052112

  14. Suppression and control of leakage field in electromagnetic helical microwiggler

    Energy Technology Data Exchange (ETDEWEB)

    Ohigashi, N. [Kansai Univ., Osaka (Japan); Tsunawaki, Y. [Osaka Sangyo Univ. (Japan); Imasaki, K. [Institute for Laser Technology, Osaka (Japan)] [and others

    1995-12-31

    Shortening the period of electromagnetic wiggler introduces both the radical increase of the leakage field and the decrease of the field in the gap region. The leakage field is severer problem in planar electromagnetic wiggler than in helical wiggler. Hence, in order to develop a short period electromagnetic wiggler, we have adopted {open_quotes}three poles per period{close_quotes} type electromagnetic helical microwiggler. In this work, we inserted the permanent magnet (PM) blocks with specific magnetized directions in the space between magnetic poles, for suppressing the leakage field flowing out from a pole face to the neighboring pole face. These PM-blocks must have higher intrinsic coersive force than saturation field of pole material. The gap field due to each pole is adjustable by controlling the leakage fields, that is, controlling the position of each iron screw set in each retainer fixing the PM-blocks. At present time, a test wiggler with period 7.8mm, periodical number 10 and gap length 4.6mm has been manufactured. Because the ratio of PM-block aperture to gap length is important parameter to suppress the leakage field, the parameter has been surveyed experimentally for PM-blocks with several dimensions of aperture. The field strength of 3-5kG (K=0.2-0.4) would be expected in the wiggler.

  15. Radio frequency leakage current from unipolar laparoscopic electrocoagulators.

    Science.gov (United States)

    DiNovo, J A

    1983-09-01

    Radio frequency (RF) leakage current has been suspected of causing accidental tissue burns associated with laparoscopic electrocoagulation used for tubal sterilization. A study was done to determine the levels of capacitively coupled RF leakage current from six unipolar laparoscopes manufactured by five companies. Leakage current values ranging from less than 100 mA to over 550 mA were measured at electrosurgical unit power settings of up to 150 w into 1,000 ohms. These levels represent 24-62% of the total electrosurgical current generated by the electrosurgical units. Using a criterion for tissue injury of 100 mA/sq cm applied for ten seconds, leakage current levels exceeding 400 mA are capable of producing burns either at the abdominal wall or to internal organs that accidentally come into contact with the body of the laparoscope. One of the six devices tested had leakage current levels higher than 400 mA at power settings lower than 100 w. Capacitance measurements between the unipolar laparoscope body and the forceps ranged from 53 to 140 picofarads. PMID:6226780

  16. Reducing water leakage into underground coal mines by aquifer dewatering

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, J. P.

    1978-01-01

    Based on stratigraphic, structural, hydrogeologic, and mining data collected during a study in central Pennsylvania, a two-dimensional, finite-difference computer model was used to simulate groundwater flow in a sandstone unit (0.3 to 11 m thick) overlying an underground mine, and to evaluate the responses of the flow system and leakage rate into the mine when hypothetical dewatering wells are introduced into the system. Simulation of well dewatering, using 25 wells, showed that negligible reduction in leakage would occur if sandstone permeability was less than 0.30 m/day. When sandstone permeability equalled 3.0 m/day, 25 wells reduced leakage by 2.4 percent.

  17. Understanding Instrumental Stokes Leakage in Murchison Widefield Array Polarimetry

    CERN Document Server

    Sutinjo, Adrian; Lenc, Emil; Wayth, Randall B; Padhi, Shantanu; Hall, Peter; Tingay, Steven J

    2014-01-01

    This paper offers an electromagnetic, more specifically array theory, perspective on understanding strong instrumental polarization effects for planar low-frequency "aperture arrays" with the Murchison Widefield Array (MWA) as an example. A long-standing issue that has been seen here is significant instrumental Stokes leakage after calibration, particularly in Stokes Q at high frequencies. A simple model that accounts for inter-element mutual coupling is presented which explains the prominence of Q leakage seen when the array is scanned away from zenith in the principal planes. On these planes, the model predicts current imbalance in the X (E-W) and Y (N-S) dipoles and hence the Q leakage. Although helpful in concept, we find that this model is inadequate to explain the full details of the observation data. This finding motivates further experimentation with more rigorous models that account for both mutual coupling and embedded element patterns. Two more rigorous models are discussed: the "full" and "average...

  18. Power Beaming Leakage Radiation as a SETI Observable

    CERN Document Server

    Benford, James N

    2016-01-01

    The most observable leakage radiation from an advanced civilization may well be from the use of power beaming to transfer energy and accelerate spacecraft. Applications suggested for power beaming involve Earth-to-space applications such as launching spacecraft to orbit, raising satellites to a higher orbit, and interplanetary concepts involving space-to-space transfers of cargo or passengers. We also quantify beam-driven launch to the outer solar system, interstellar precursors and ultimately starships. We estimate the principal observable parameters of power beaming leakage. Extraterrestrial civilizations would know their power beams could be observed, and so could put a message on the power beam and broadcast it for our receipt at little additional energy or cost. By observing leakage from power beams we may find a message embedded on the beam. Recent observations of the anomalous star KIC 8462852 by the Allen Telescope Array (ATA) set some limits on extraterrestrial power beaming in that system. We show t...

  19. Air Leakage of U.S. Homes: Model Prediction

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max H.; McWilliams, Jennifer A.

    2007-01-01

    Air tightness is an important property of building envelopes. It is a key factor in determining infiltration and related wall-performance properties such as indoor air quality, maintainability and moisture balance. Air leakage in U.S. houses consumes roughly 1/3 of the HVAC energy but provides most of the ventilation used to control IAQ. The Lawrence Berkeley National Laboratory has been gathering residential air leakage data from many sources and now has a database of more than 100,000 raw measurements. This paper uses a model developed from that database in conjunction with US Census Bureau data for estimating air leakage as a function of location throughout the US.

  20. Containment integrated leakage rate test (ILRT) of Indian PHWR

    International Nuclear Information System (INIS)

    Integrated Leakage Rate Test (ILRT) of containment system plays a very important role in safety of a Nuclear Power Plant. Containment system constitutes the last physical barrier to release of radioactivity from the core and is called upon to mitigate the consequences of not only accidents within the design basis, but also some of the highly unlikely severe accidents. Hence, leak tightness of containment becomes uttermost priority for the safety of plant personnel and public. The containment and associated ESFs are tested before the first criticality and there after periodically during service. The pre-operational integrated leakage rate is carried out at LOCA based design pressure, at periodic test pressure and at some intermediate pressure points to assess the leakage characteristics. This paper summarizes the various requirements and activities relevant to the ILRT of the Indian Pressurized Heavy Water Reactor (PHWR) containment system. (author)

  1. Identifying and Managing Gas Leakage from Subsurface Sources

    Science.gov (United States)

    Benson, S. M.

    2015-12-01

    Subsurface gas accumulations exist from both natural sources such as hydrocarbon reservoirs, as well as, man-made sources such as natural gas storage, gas pipelines, CO2 storage, or even H2 storage. Both natural and manmade sources of subsurface gases have the potential to leak to the surface. Leakage can cause safety hazards and detrimental impacts associated with the release of greenhouse gases into the atmosphere. Leak management, which involves identifying, characterizing, assessing, and remediating leakage requires a coordinated and systematic approach to effectively deal with these occurrences. Here an overall workflow for leak management is presented, along with technological options and challenges for successful implementation. Many tools and approaches for leak management are available and in use today. However, the increased attention to leakage from a larger variety of sources, particularly associated with legacy facilities and infrastructure, raises new issues and challenges that are highlighted here.

  2. On the Connection between Leakage Tolerance and Adaptive Security

    DEFF Research Database (Denmark)

    Nielsen, Jesper Buus; Venturi, Daniele; Zottarel, Angela

    2013-01-01

    We revisit the context of leakage-tolerant interactive protocols as defined by Bitanski, Canetti and Halevi (TCC 2012). Our contributions can be summarized as follows: For the purpose of secure message transmission, any encryption protocol with message space M and secret key space SK tolerating...... at the end of the protocol execution, if and only if the protocol has passive adaptive security against an adaptive corruption of one party at the end of the protocol execution. This shows that as soon as a little leakage is tolerated, one needs full adaptive security. In case more than one party can...... be corrupted, we get that leakage tolerance is equivalent to a weaker form of adaptivity, which we call semi-adaptivity. Roughly, a protocol has semi-adaptive security if there exist a simulator which can simulate the internal state of corrupted parties, however, such a state is not required...

  3. Impact of the Indonesian throughflow on Agulhas leakage

    Directory of Open Access Journals (Sweden)

    D. Le Bars

    2013-02-01

    Full Text Available Using ocean models of different complexity we show that opening the Indonesian Passage between the Pacific and the Indian Ocean increases the input of Indian Ocean water into the South Atlantic via the Agulhas leakage. In a strongly eddying global ocean model this response results from an increased Agulhas Current transport and a constant proportion of Agulhas retroflection south of Africa. The leakage increases through an increased frequency of ring shedding events. In an idealized two-layer and flat-bottom eddy resolving model, the proportion of the Agulhas Current transport that retroflects is (for a wide range of wind stress forcing not affected by an opening of the Indonesian Passage. A linear ocean model is not able to explain this behavior which reveals the importance of mixed barotropic/baroclinic instabilities in controlling the Agulhas leakage.

  4. An Investigation of Tendon Corrosion-Inhibitor Leakage into Concrete

    Energy Technology Data Exchange (ETDEWEB)

    Costello, J.F.; Naus, D.J.; Oland, C.B.

    1999-07-05

    During inspections performed at US nuclear power plants several years ago, some of the prestressed concrete containment had experienced leakage of the tendon sheathing filler. A study was conducted to indicate the extent of the leakage into the concrete and its potential effects on concrete properties. Concrete core samples were obtained from the Trojan Nuclear Plant. Examination and testing of the core samples indicated that the appearance of tendon sheathing filler on the surface was due to leakage of the filler from the conduits and its subsequent migration to the concrete surface through cracks that were present. Migration of the tendon sheathing filler was confined to the cracks with no perceptible movement into the concrete. Results of compressive strength tests indicated that the concrete quality was consistent in the containment and that the strength had increased relative to the strength at 28 days age.

  5. Determination of leakage in blast furnaces cooling plates

    International Nuclear Information System (INIS)

    Blast furnace walls are cooled by the circulation of water through copper plates inserted into the blast furnace refractory lining. Plates are fed by circular pipelines, called distribution rings, installed at different levels of the reactor. Because of normal corrosion, plates wear away and can eventually perforate, allowing the leakage of cooling water inside the blast furnace. A system has been designed and installed in order to confirm the eventual occurrence of leakages in the cooling plates of a blast furnace refractory lining. The system injects a solution of tritium into the feeding pipeline and determines, by means of liquid scintillation counting, the concentration of tritium in the exhausting gases at the top of the blast furnace. The system was tested under different blast furnace operating conditions, and allowed the detection and determination of leakages greater than 0.5 1/min. Following necessary maintenance, the system also confirmed the satisfactory results of the corrective actions. (author). 48 refs., 13 figs., 29 tabs

  6. On camera-based smoke and gas leakage detection

    Energy Technology Data Exchange (ETDEWEB)

    Nyboe, Hans Olav

    1999-07-01

    Gas detectors are found in almost every part of industry and in many homes as well. An offshore oil or gas platform may host several hundred gas detectors. The ability of the common point and open path gas detectors to detect leakages depends on their location relative to the location of a gas cloud. This thesis describes the development of a passive volume gas detector, that is, one than will detect a leakage anywhere in the area monitored. After the consideration of several detection techniques it was decided to use an ordinary monochrome camera as sensor. Because a gas leakage may perturb the index of refraction, parts of the background appear to be displaced from their true positions, and it is necessary to develop algorithms that can deal with small differences between images. The thesis develops two such algorithms. Many image regions can be defined and several feature values can be computed for each region. The value of the features depends on the pattern in the image regions. The classes studied in this work are: reference, gas, smoke and human activity. Test show that observation belonging to these classes can be classified fairly high accuracy. The features in the feature set were chosen and developed for this particular application. Basically, the features measure the magnitude of pixel differences, size of detected phenomena and image distortion. Interesting results from many experiments are presented. Most important, the experiments show that apparent motion caused by a gas leakage or heat convection can be detected by means of a monochrome camera. Small leakages of methane can be detected at a range of about four metres. Other gases, such as butane, where the densities differ more from the density of air than the density of methane does, can be detected further from the camera. Gas leakages large enough to cause condensation have been detected at a camera distance of 20 metres. 59 refs., 42 figs., 13 tabs.

  7. Measuring Agulhas Current strength and leakage from satellite altimetry

    Science.gov (United States)

    Le Bars, Dewi; De Ruijter, Wilhelmus P. M.; Dijkstra, Henk A.

    2013-04-01

    The Agulhas leakage is a flux of relatively warm and salty water from the Indian Ocean to the South Atlantic Ocean. It occurs south of the African continent where the Agulhas Current retroflects and sheds large anticyclonic eddies that quickly break up and mix with the surrounding water. This is one of the most energetic regions of the world ocean and the Agulhas leakage is therefore very difficult to quantify. In recent years two independent studies (Biastoch et al. 2009, Rouault et al. 2009) using different ocean models pointed out the possibility that the strength of the Agulhas leakage could have increased over the last decades. Unfortunately several discrepancies exist between these two studies on the magnitude and the causes of this increase showing the limitations of numerical modelling in this area. In this work we use a combination of along-track and mapped satellite geostrophic velocities to compute the strength of the Agulhas Current and to follow Lagrangian particles released in its core. The results confirm a positive trend of the volume of Agulhas leakage over the last two decades. This allows us to investigate the dependence of the leakage to upstream conditions like the Agulhas Current transport, the pattern and strength of the westerly winds and to test previous theories on the relations between these factors. Biastoch, A., Böning, C. W., Schwarzkopf, F. U. and Lutjeharms, J. R. E.: Increase in Agulhas leakage due to poleward shift of Southern Hemisphere westerlies, Nature, 462(7272), 495-498, doi:10.1038/nature08519, 2009. Rouault, M., Penven, P. and Pohl, B.: Warming in the Agulhas Current system since the 1980's, Geophys. Res. Lett, 36(L12602), doi:10.1029/2009GL037987, 2009.

  8. Cuffed Endotracheal Tube Size and Leakage in Pediatric Tracheal Models

    Directory of Open Access Journals (Sweden)

    Jun Hyun Kim

    2014-04-01

    Full Text Available Object: Cuffed endotracheal tubes are increasingly used in pediatric patients in the hope that they can reduce air leakage and tube size mismatch by just inflating the cuff. Authors compared influence of various tube sizes and different levels of cuff pressures to air leakage around the cuff, in artificial tracheal models. Methods: Six PVC cylinders of different internal diameters (ID: 8.15, 8.50, 9.70, 12.05, 14.50, and 20.00 mm were prepared. An artificial lung connected with cylinder was ventilated with an anesthesia machine. Cuffed endotracheal tubes of different sizes (ID 3.0~8.0 were located in the cylinders and the cuff was inflated with various pressures (15, 20, 25, 30 and 35 cm H2O. Expiratory tidal volume was measured with more than 25% loss of baseline expiratory tidal volume was considered significant air leakage. Results: Tube sizes same as, or larger than ID 5.0 didn’t show significant air leakage for any trachea model, only if the inflated cuff size is larger than the cylinder ID, except ID 5.5 tube at cuff pressure 15 cm H2O and 20 cm H2O, in 12.05 mm cylinder. Tubes sizes same as or smaller than ID 4.5, which have short cuff lengths and sizes than tubes larger than, or same as ID 5.0, leaked significantly at any tracheal models, except ID 4.5 tube at cuff pressure 35 cm H2O, in 8.50 mm cylinder. Conclusion: In PVC pediatric tracheal models, tubes same as, or smaller than ID 4.5 are inferior to tubes same as, or larger than ID 5.0 in preventing air leakage, and may need a higher cuff pressure to reduce air leakage. Further clinical studies could be designed based on our results.

  9. Remote laser detection of natural gas leakages from pipelines

    International Nuclear Information System (INIS)

    A differential absorption lidar based on a tunable TEA CO2 laser emitting at 42 lines of the 'hot' 0111 - 1110 band in the range from 10.9 to 11.4 μm is developed for detecting natural gas leakages from oil pipelines by measuring the ethane content in the atmosphere. The ethane detection sensitivity is 0.9 ppm km. The presence of methane does not distort the measurement results. The developed lidar can detect the natural gas leakage from kilometre heights at the flying velocities up to 200 km h-1 and a probe pulse repetition rate of 5 Hz. (laser applications and other topics in quantum electronics)

  10. Leakage tests of wall segments of reactor containments

    International Nuclear Information System (INIS)

    Two prestressed concrete wall segments simulating portions of containment walls were loaded by axial tensile forces to cause cracking of the concrete. At each load increment air pressure was applied in steps up to 21 psi to one side of the segment and the rate of leakage of air through the cracked concrete section was measured. A theoretical equation for the flow of air through concrete cracks is developed and the results from one leakage test are used to determine the dimensionless constant required for this equation. (author)

  11. Properties of Leakage Corrosion of Concrete and Its Durability

    Institute of Scientific and Technical Information of China (English)

    GE Xueliang; FANG Kunhe; ZENG Li; CHEN Xia

    2008-01-01

    The properties and mechanism of concrete under water leakage corrosion were studied in terms of the dissolution of calcium oxide and silicon oxide from concrete and the variation of pH value of permeate water.The experimental results show that the amount of calcium oxide and silicon oxide dissolved from per cubic meter of concrete gradually decrease with penetration time and ultimately stabilize at a certain value.The pH value of permeate water descend along with penetration time.The durability of concrete under leakage corrosion was analyzed by a formula fitted on the dissolved amount of calcium oxide.

  12. Transformerless photovoltaic inverters with leakage current and pulsating power elimination

    DEFF Research Database (Denmark)

    Tang, Yi; Yao, Wenli; Wang, H.;

    2015-01-01

    This paper presents a transformerless inverter topology, which is capable of simultaneously solving leakage current and pulsating power issues in grid-connected photovoltaic (PV) systems. Without adding any additional components to the system, the leakage current caused by the PV...... that is inherent in single-phase PV systems. By properly injecting CM voltages to the output filter capacitors, the pulsating power can be decoupled from the dc-link. Therefore, it is possible to use long lifetime film capacitors instead of electrolytic capacitors to improve the reliability of the PV system...

  13. 40 CFR 264.252 - Action leakage rate.

    Science.gov (United States)

    2010-07-01

    ... 264.252 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Waste... for waste pile units subject to § 264.251(c) or (d). The action leakage rate is the maximum...

  14. Development of Wireless System for Containment Integrated Leakage Rate Test

    International Nuclear Information System (INIS)

    The containment system leakage rate should be estimated periodically with reliable test equipment. In light-water reactor nuclear power plants, ANSI/ANS- 56.8 is a basis for determining leakage rates. Two types of data acquisition system, centralized type and networked type, has been used. In centralized type, all sensors are connected directly from sensors in the containment to the measuring equipment outside the building. The other hand, the networked type has several branch chains which connect one group of the network-sensors together. To test leakage rate, more than 20 temperature sensors and 6 humidity sensors, which are different for each plant, should be installed on a specific level in the containment. A wireless technology gives the benefits such as reducing installation efforts, making pretest easy, so it is widely used more and more in the plant monitoring. As the containment system has many kinds of complex barriers to the radio frequency, the radio power and frequency band for better transmission rate as well as the interference by the radio frequency should be considered. The overview of the wireless sensor system for the containment leakage rate test is described here and the test results on Yonggwang unit 4 PWR plant is presented

  15. Leakage Currents and Gas Generation in Advanced Wet Tantalum Capacitors

    Science.gov (United States)

    Teverovsky, Alexander

    2015-01-01

    Currently, military grade, established reliability wet tantalum capacitors are among the most reliable parts used for space applications. This has been achieved over the years by extensive testing and improvements in design and materials. However, a rapid insertion of new types of advanced, high volumetric efficiency capacitors in space systems without proper testing and analysis of degradation mechanisms might increase risks of failures. The specifics of leakage currents in wet electrolytic capacitors is that the conduction process is associated with electrolysis of electrolyte and gas generation resulting in building up of internal gas pressure in the parts. The risk associated with excessive leakage currents and increased pressure is greater for high value advanced wet tantalum capacitors, but it has not been properly evaluated yet. In this work, in Part I, leakages currents in various types of tantalum capacitors have been analyzed in a wide range of voltages, temperatures, and time under bias. Gas generation and the level of internal pressure have been calculated in Part II for different case sizes and different hermeticity leak rates to assess maximal allowable leakage currents. Effects related to electrolyte penetration to the glass seal area have been studied and the possibility of failures analyzed in Part III. Recommendations for screening and qualification to reduce risks of failures have been suggested.

  16. Anastomotic leakage after anterior resection for rectal cancer: risk factors

    DEFF Research Database (Denmark)

    Bertelsen, C A; Andreasen, A H; Jørgensen, Torben;

    2010-01-01

    OBJECTIVE: The study aimed to identify risk factors for clinical anastomotic leakage (AL) after anterior resection for rectal cancer in a consecutive national cohort. METHOD: All patients with an initial first diagnosis of colorectal adenocarcinoma were prospectively registered in a national...

  17. Characterization of CO2 leakage into the freshwater body

    DEFF Research Database (Denmark)

    Singh, Ashok; Delfs, Jens Olaf; Shao, H.;

    2013-01-01

    urrent research into CO2 capture and storage is dominated by improving the CO2 storage capacity. In this context, risk related to CO2 leakage is an important issue which may cause environmental problems, particularly when freshwater resources nearby are intruded by the CO2 plume. In this work...

  18. Leakage detection in underground gas mains with radioaktive argon

    International Nuclear Information System (INIS)

    In the field of gas supply, radionuclide techniques are suitable for the routine monitoring of transport mains by means of highly active tracer clouds and a measuring scraper as well as for exact leakage detection in local gas distribution systems. Very good results are obtained in the case of mains lying lower than 1.5 m if the length and alignment of the pipe section allow a towing probe to be pulled through. This was investigated systematically on a model stretch under practical conditions. The attempts to detect leakages were made with the aid of the radioactive isotope 41Ar. Under conditions close to practice concerning pipe bedding, branching, pre-pressure, and leakage diameter, a leak with leakage rates as small as approx. 1 l/min could be measured with the aid of a towing probe with a precision of +-0.5 m. This accuracy is another advantage of this method. Branching and fittings with a big dead volume do not interfere with the evaluation. The investment for this method can be compared to other physical/technical investigations on mains, e.g. weld seam tests. (orig./LN)

  19. Thresholds of information leakage for speech security outside meeting rooms.

    Science.gov (United States)

    Robinson, Matthew; Hopkins, Carl; Worrall, Ken; Jackson, Tim

    2014-09-01

    This paper describes an approach to provide speech security outside meeting rooms where a covert listener might attempt to extract confidential information. Decision-based experiments are used to establish a relationship between an objective measurement of the Speech Transmission Index (STI) and a subjective assessment relating to the threshold of information leakage. This threshold is defined for a specific percentage of English words that are identifiable with a maximum safe vocal effort (e.g., "normal" speech) used by the meeting participants. The results demonstrate that it is possible to quantify an offset that links STI with a specific threshold of information leakage which describes the percentage of words identified. The offsets for male talkers are shown to be approximately 10 dB larger than for female talkers. Hence for speech security it is possible to determine offsets for the threshold of information leakage using male talkers as the "worst case scenario." To define a suitable threshold of information leakage, the results show that a robust definition can be based upon 1%, 2%, or 5% of words identified. For these percentages, results are presented for offset values corresponding to different STI values in a range from 0.1 to 0.3. PMID:25190390

  20. Blower-door techniques for measuring interzonal leakage

    Energy Technology Data Exchange (ETDEWEB)

    Hult, Erin L.; Sherman, Max H.; Walker, Iain

    2013-01-01

    Abstract The standard blower door test methods, such as ASTM E779, describe how to use a single blower door to determine the total leakage of a single-zone structure such as a detached single-family home. There are no standard test methods for measuring interzonal leakage in a two-zone or multi-zone building envelope such as might be encountered in with an attached garage or in a multifamily building. Some practitioners have been using techniques that involve making multiple measurements with a single blower door as well as combined measurements using multiple blower doors. Even for just two zones there are dozens of combinations of one-door and two-door test protocols that could conceivably be used to determine the interzonal air tightness. We examined many of these two-zone configurations using both simulation and measured data to estimate the accuracy and precision of each technique for realistic measurement scenarios. We also considered the impact of taking measurements at a single pressure versus over multiple pressures. We compared the various techniques and evaluated them for specific uses. Some techniques work better in one leakage regime; some are more sensitive to wind and other noise; some are more suited to determining only a subset of the leakage values. This paper makes recommendations on which techniques to use or not use for various cases and provides data that could be used to develop future test methods.

  1. Visual Inspection of Water Leakage from Ground Penetrating Radar Radargram

    Science.gov (United States)

    Halimshah, N. N.; Yusup, A.; Mat Amin, Z.; Ghazalli, M. D.

    2015-10-01

    Water loss in town and suburban is currently a significant issue which reflect the performance of water supply management in Malaysia. Consequently, water supply distribution system has to be maintained in order to prevent shortage of water supply in an area. Various techniques for detecting a mains water leaks are available but mostly are time-consuming, disruptive and expensive. In this paper, the potential of Ground Penetrating Radar (GPR) as a non-destructive method to correctly and efficiently detect mains water leaks has been examined. Several experiments were designed and conducted to prove that GPR can be used as tool for water leakage detection. These include instrument validation test and soil compaction test to clarify the maximum dry density (MDD) of soil and simulation studies on water leakage at a test bed consisting of PVC pipe burying in sand to a depth of 40 cm. Data from GPR detection are processed using the Reflex 2D software. Identification of water leakage was visually inspected from the anomalies in the radargram based on GPR reflection coefficients. The results have ascertained the capability and effectiveness of the GPR in detecting water leakage which could help avoiding difficulties with other leak detection methods.

  2. Risk factors for clinical anastomotic leakage after right hemicolectomy

    DEFF Research Database (Denmark)

    Jessen, Mikkel; Nerstrøm, Malene; Wilbek, Therese Emilie;

    2016-01-01

    PURPOSE: Anastomotic leakage (AL) after right hemicolectomy is a devastating complication, and risk factors for AL in this setting are rarely investigated exclusively. Recent reports suggest that anastomotic type may influence the rate of AL in ileocolic anastomoses. We investigated risk factors ...

  3. Leakage of fluid in different types of tracheal tubes.

    Science.gov (United States)

    Winklmaier, U; Wüst, K; Schiller, S; Wallner, F

    2006-10-01

    The aim of this study was to evaluate leakage of liquids, i.e., water and saliva, past low-pressure cuffs of tracheostomy tubes. Three different types of tracheostomy tubes, TRACOE vario (TRACOE Medical GmbH, Germany), Rüsch Ultra-Tracheoflex (Rüsch GmbH, Germany), and Portex Blue Line Ultra (Smiths Medical, UK) were tested in isolated pig tracheas. Sixty samples (10 tubes each of 7- and 8-mm inner diameter of each type) were used. Four different experiments were devised: type 1 (water and artificial ventilation), type 2 (water and no artificial ventilation), type 3 (saliva and artificial ventilation), and type 4 (saliva and no artificial ventilation). Six milliliters of water or artificial saliva were infused over the cuff and the volume of fluid that leaked past the cuff was measured after 5, 10, and 15 min. Intracuff pressure was also measured three times. The saliva experiments resulted in less leakage than the water experiments. Leakage after treatment with water or artificial saliva is higher without artificial ventilation than with ventilation. The amount of leakage among the tubes with respect to manufacturer showed statistically significant results. However, there were no differences among tracheostomy tubes with respect to internal diameter.

  4. Method for Determining Leakage Velocities through the Bottom of Reservoirs

    International Nuclear Information System (INIS)

    A new method based on an idea of converting a slow flow through a chosen area of reservoir bottom to a fast flow in a pipe of a small diameter is presented. If the chosen area is tightly covered by a bottomless cylinder with an outlet through a pipe then the product of leakage velocity and the area covered is equal to the product of flow velocity in the pipe and the pipe cross-section. Even extremely low leakage velocities render measurable velocities in the pipe if its cross-section is very small in comparison with the covered area. This idea can be used for leakage velocity measurements if the measuring device does not disturb natural flow lines. Conditions under which this requirement is satisfied are considered in detail. A measuring device constructed according to these conditions and described in the paper can measure leakage velocities from 5 x 10-7 to 3 x 10-3 cm/sec. The flow velocity in the measuring pipe is known from the transit time measurement of an injected pulse of a radioisotope. (author)

  5. Exploitation of Unintentional Information Leakage from Integrated Circuits

    Science.gov (United States)

    Cobb, William E.

    2011-01-01

    The information leakage of electronic devices, especially those used in cryptographic or other vital applications, represents a serious practical threat to secure systems. While physical implementation attacks have evolved rapidly over the last decade, relatively little work has been done to allow system designers to effectively counter the…

  6. Localization of protein aggregation in Escherichia coli is governed by diffusion and nucleoid macromolecular crowding effect.

    Science.gov (United States)

    Coquel, Anne-Sophie; Jacob, Jean-Pascal; Primet, Mael; Demarez, Alice; Dimiccoli, Mariella; Julou, Thomas; Moisan, Lionel; Lindner, Ariel B; Berry, Hugues

    2013-04-01

    Aggregates of misfolded proteins are a hallmark of many age-related diseases. Recently, they have been linked to aging of Escherichia coli (E. coli) where protein aggregates accumulate at the old pole region of the aging bacterium. Because of the potential of E. coli as a model organism, elucidating aging and protein aggregation in this bacterium may pave the way to significant advances in our global understanding of aging. A first obstacle along this path is to decipher the mechanisms by which protein aggregates are targeted to specific intercellular locations. Here, using an integrated approach based on individual-based modeling, time-lapse fluorescence microscopy and automated image analysis, we show that the movement of aging-related protein aggregates in E. coli is purely diffusive (Brownian). Using single-particle tracking of protein aggregates in live E. coli cells, we estimated the average size and diffusion constant of the aggregates. Our results provide evidence that the aggregates passively diffuse within the cell, with diffusion constants that depend on their size in agreement with the Stokes-Einstein law. However, the aggregate displacements along the cell long axis are confined to a region that roughly corresponds to the nucleoid-free space in the cell pole, thus confirming the importance of increased macromolecular crowding in the nucleoids. We thus used 3D individual-based modeling to show that these three ingredients (diffusion, aggregation and diffusion hindrance in the nucleoids) are sufficient and necessary to reproduce the available experimental data on aggregate localization in the cells. Taken together, our results strongly support the hypothesis that the localization of aging-related protein aggregates in the poles of E. coli results from the coupling of passive diffusion-aggregation with spatially non-homogeneous macromolecular crowding. They further support the importance of "soft" intracellular structuring (based on macromolecular

  7. Localization of protein aggregation in Escherichia coli is governed by diffusion and nucleoid macromolecular crowding effect.

    Directory of Open Access Journals (Sweden)

    Anne-Sophie Coquel

    2013-04-01

    Full Text Available Aggregates of misfolded proteins are a hallmark of many age-related diseases. Recently, they have been linked to aging of Escherichia coli (E. coli where protein aggregates accumulate at the old pole region of the aging bacterium. Because of the potential of E. coli as a model organism, elucidating aging and protein aggregation in this bacterium may pave the way to significant advances in our global understanding of aging. A first obstacle along this path is to decipher the mechanisms by which protein aggregates are targeted to specific intercellular locations. Here, using an integrated approach based on individual-based modeling, time-lapse fluorescence microscopy and automated image analysis, we show that the movement of aging-related protein aggregates in E. coli is purely diffusive (Brownian. Using single-particle tracking of protein aggregates in live E. coli cells, we estimated the average size and diffusion constant of the aggregates. Our results provide evidence that the aggregates passively diffuse within the cell, with diffusion constants that depend on their size in agreement with the Stokes-Einstein law. However, the aggregate displacements along the cell long axis are confined to a region that roughly corresponds to the nucleoid-free space in the cell pole, thus confirming the importance of increased macromolecular crowding in the nucleoids. We thus used 3D individual-based modeling to show that these three ingredients (diffusion, aggregation and diffusion hindrance in the nucleoids are sufficient and necessary to reproduce the available experimental data on aggregate localization in the cells. Taken together, our results strongly support the hypothesis that the localization of aging-related protein aggregates in the poles of E. coli results from the coupling of passive diffusion-aggregation with spatially non-homogeneous macromolecular crowding. They further support the importance of "soft" intracellular structuring (based on

  8. D3, the new diffractometer for the macromolecular crystallography beamlines of the Swiss Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, Martin R., E-mail: mfuchs@bnl.gov [Paul Scherrer Institute, 5232 Villigen PSI (Switzerland); Brookhaven National Laboratory, Mail Stop 745, Upton, NY 11973 (United States); Pradervand, Claude; Thominet, Vincent; Schneider, Roman; Panepucci, Ezequiel; Grunder, Marcel; Gabadinho, Jose; Dworkowski, Florian S. N.; Tomizaki, Takashi; Schneider, Jörg; Mayer, Aline; Curtin, Adrian; Olieric, Vincent; Frommherz, Uli; Kotrle, Goran; Welte, Jörg; Wang, Xinyu; Maag, Stephan [Paul Scherrer Institute, 5232 Villigen PSI (Switzerland); Schulze-Briese, Clemens [DECTRIS Ltd, Neuenhoferstrasse 107, 5400 Baden (Switzerland); Wang, Meitian [Paul Scherrer Institute, 5232 Villigen PSI (Switzerland)

    2014-02-04

    A new diffractometer for microcrystallography has been developed for the three macromolecular crystallography beamlines of the Swiss Light Source. A new diffractometer for microcrystallography has been developed for the three macromolecular crystallography beamlines of the Swiss Light Source. Building upon and critically extending previous developments realised for the high-resolution endstations of the two undulator beamlines X06SA and X10SA, as well as the super-bend dipole beamline X06DA, the new diffractometer was designed to the following core design goals. (i) Redesign of the goniometer to a sub-micrometer peak-to-peak cylinder of confusion for the horizontal single axis. Crystal sizes down to at least 5 µm and advanced sample-rastering and scanning modes are supported. In addition, it can accommodate the new multi-axis goniometer PRIGo (Parallel Robotics Inspired Goniometer). (ii) A rapid-change beam-shaping element system with aperture sizes down to a minimum of 10 µm for microcrystallography measurements. (iii) Integration of the on-axis microspectrophotometer MS3 for microscopic sample imaging with 1 µm image resolution. Its multi-mode optical spectroscopy module is always online and supports in situ UV/Vis absorption, fluorescence and Raman spectroscopy. (iv) High stability of the sample environment by a mineral cast support construction and by close containment of the cryo-stream. Further features are the support for in situ crystallization plate screening and a minimal achievable detector distance of 120 mm for the Pilatus 6M, 2M and the macromolecular crystallography group’s planned future area detector Eiger 16M.

  9. A Web Resource for Standardized Benchmark Datasets, Metrics, and Rosetta Protocols for Macromolecular Modeling and Design.

    Directory of Open Access Journals (Sweden)

    Shane Ó Conchúir

    Full Text Available The development and validation of computational macromolecular modeling and design methods depend on suitable benchmark datasets and informative metrics for comparing protocols. In addition, if a method is intended to be adopted broadly in diverse biological applications, there needs to be information on appropriate parameters for each protocol, as well as metrics describing the expected accuracy compared to experimental data. In certain disciplines, there exist established benchmarks and public resources where experts in a particular methodology are encouraged to supply their most efficient implementation of each particular benchmark. We aim to provide such a resource for protocols in macromolecular modeling and design. We present a freely accessible web resource (https://kortemmelab.ucsf.edu/benchmarks to guide the development of protocols for protein modeling and design. The site provides benchmark datasets and metrics to compare the performance of a variety of modeling protocols using different computational sampling methods and energy functions, providing a "best practice" set of parameters for each method. Each benchmark has an associated downloadable benchmark capture archive containing the input files, analysis scripts, and tutorials for running the benchmark. The captures may be run with any suitable modeling method; we supply command lines for running the benchmarks using the Rosetta software suite. We have compiled initial benchmarks for the resource spanning three key areas: prediction of energetic effects of mutations, protein design, and protein structure prediction, each with associated state-of-the-art modeling protocols. With the help of the wider macromolecular modeling community, we hope to expand the variety of benchmarks included on the website and continue to evaluate new iterations of current methods as they become available.

  10. A Web Resource for Standardized Benchmark Datasets, Metrics, and Rosetta Protocols for Macromolecular Modeling and Design.

    Science.gov (United States)

    Ó Conchúir, Shane; Barlow, Kyle A; Pache, Roland A; Ollikainen, Noah; Kundert, Kale; O'Meara, Matthew J; Smith, Colin A; Kortemme, Tanja

    2015-01-01

    The development and validation of computational macromolecular modeling and design methods depend on suitable benchmark datasets and informative metrics for comparing protocols. In addition, if a method is intended to be adopted broadly in diverse biological applications, there needs to be information on appropriate parameters for each protocol, as well as metrics describing the expected accuracy compared to experimental data. In certain disciplines, there exist established benchmarks and public resources where experts in a particular methodology are encouraged to supply their most efficient implementation of each particular benchmark. We aim to provide such a resource for protocols in macromolecular modeling and design. We present a freely accessible web resource (https://kortemmelab.ucsf.edu/benchmarks) to guide the development of protocols for protein modeling and design. The site provides benchmark datasets and metrics to compare the performance of a variety of modeling protocols using different computational sampling methods and energy functions, providing a "best practice" set of parameters for each method. Each benchmark has an associated downloadable benchmark capture archive containing the input files, analysis scripts, and tutorials for running the benchmark. The captures may be run with any suitable modeling method; we supply command lines for running the benchmarks using the Rosetta software suite. We have compiled initial benchmarks for the resource spanning three key areas: prediction of energetic effects of mutations, protein design, and protein structure prediction, each with associated state-of-the-art modeling protocols. With the help of the wider macromolecular modeling community, we hope to expand the variety of benchmarks included on the website and continue to evaluate new iterations of current methods as they become available.

  11. The "macromolecular tourist": universal temperature dependence of thermal diffusion in aqueous colloidal suspensions.

    Science.gov (United States)

    Iacopini, S; Rusconi, R; Piazza, R

    2006-01-01

    By performing measurements on a large class of macromolecular and colloidal systems, we show that thermophoresis (particle drift induced by thermal gradients) in aqueous solvents displays a distinctive universal dependence on temperature. For systems of particles interacting via temperature-independent forces, this behavior is strictly related to the solvent thermal expansivity, while an additional, T-independent term is needed to account for the behavior of "thermophilic" (migrating to the warmth) particles. The former relation between thermophoresis and thermal expansion may be exploited to envisage other fruitful studies of colloidal diffusion in inhomogeneous fluids. PMID:16446985

  12. INFLUENCE OF THE SOLVENT SWELLING ON MACROMOLECULAR CHOLESTERIC LIQUID CRYSTALLINE STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    Jia Zeng; Yong Huang

    1999-01-01

    Ethyl-cyanoethyl cellulose [(E-CE)C]/cross-linked polyacrylic acid [PAA] molecular composites with cholesteric order were prepared. It was found that the macromolecular cholesteric structure was changed with the swelling of PAA in the composites. The selective reflection of the cholesteric phase shifted to the longer wavelength and the X-ray diffraction angle shifted to the high angle direction during swelling, which suggested that the cholesteric pitch and the number of the layers of ordered (E-CE)C chains in the cholesteric phase were increased.

  13. Relations between functionality and macromolecular properties of alterated coals: the behaviour in solubility and swelling

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, P.N.; Gruber, R.; Bimer, J.; Salbut, P.D.; Djega-Mariadassou, G.; Kruchinin, A.V.; Kuznetsova, L.I. [Institute of Chemistry and Chemico-Metallurgical Processes, Krasnoyarsk (Russian Federation)

    1995-12-31

    Describes the study of the effects of chemical alteration of brown and bituminous coals on the solubility and swelling behaviour. A variety of chemical procedures such as ion-exchange with HCl, O-methylation and reductive methylation, reduction with LiAlH{sub 4} and with K/isopropanol in THF and oxidation with performic acid was applied in order to vary the oxygen functionality, the content of the alkyl substitutes and the proportion of aromatic to hydroaromatic rings. The extent of degradation of the macromolecular structure was evaluated as a function of chemical alteration. 6 refs., 2 tabs.

  14. Chirality as a physical aspect of structure formation in biological macromolecular systems

    Science.gov (United States)

    Malyshko, E. V.; Tverdislov, V. A.

    2016-08-01

    A novel regularity of hierarchical structures is found in the formation of chiral biological macromolecular systems. The formation of structures with alternating chirality (helical structures) serves as an instrument of stratification. The ability of a carbon atom to form chiral compounds is an important factor that determined the carbon basis of living systems on the Earth as well as their development through a series of chiral bifurcations. In the course of biological evolution, the helical structures became basic elements of the molecular machines in the cell. The discreteness of structural levels allowed the mechanical degrees of freedom formation in the molecular machines in the cell.

  15. Radiation leakage dose from Elekta electron collimation system.

    Science.gov (United States)

    Pitcher, Garrett M; Hogstrom, Kenneth R; Carver, Robert L

    2016-01-01

    This study provided baseline data required for a greater project, whose objective was to design a new Elekta electron collimation system having significantly lighter electron applicators with equally low out-of field leakage dose. Specifically, off-axis dose profiles for the electron collimation system of our uniquely configured Elekta Infinity accelerator with the MLCi2 treatment head were measured and calculated for two primary purposes: 1) to evaluate and document the out-of-field leakage dose in the patient plane and 2) to validate the dose distributions calculated using a BEAMnrc Monte Carlo (MC) model for out-of-field dose profiles. Off-axis dose profiles were measured in a water phantom at 100 cm SSD for 1 and 2 cm depths along the in-plane, cross-plane, and both diagonal axes using a cylindrical ionization chamber with the 10 × 10 and 20 × 20 cm2 applicators and 7, 13, and 20 MeV beams. Dose distributions were calculated using a previously developed BEAMnrc MC model of the Elekta Infinity accelerator for the same beam energies and applicator sizes and compared with measurements. Measured results showed that the in-field beam flatness met our acceptance criteria (± 3% on major and ±4% on diagonal axes) and that out-of-field mean and maximum percent leakage doses in the patient plane met acceptance criteria as specified by the International Electrotechnical Commission (IEC). Cross-plane out-of-field dose profiles showed greater leakage dose than in-plane profiles, attributed to the curved edges of the upper X-ray jaws and multileaf collimator. Mean leakage doses increased with beam energy, being 0.93% and 0.85% of maximum central axis dose for the 10 × 10 and 20 × 20 cm2 applicators, respectively, at 20 MeV. MC calculations predicted the measured dose to within 0.1% in most profiles outside the radiation field; however, excluding model-ing of nontrimmer applicator components led to calculations exceeding measured data by as much as 0.2% for some regions

  16. Macromolecular liquids

    Energy Technology Data Exchange (ETDEWEB)

    Safinya, C.R.; Safran, S.A. (Exxon Research and Engineering Co., Annandale, NJ (US)); Pincus, P.A. (Univ. of California at Santa Barbara, Santa Barbara, CA (US))

    1990-01-01

    Liquids include a broad range of material systems which are of high scientific and technological interest. Generally speaking, these are partially ordered or disordered phases where the individual molecular species have organized themselves on length scales which are larger than simple fluids, typically between 10 Angstroms and several microns. The specific systems reported on in this book include membranes, microemulsions, micelles, liquid crystals, colloidal suspensions, and polymers. They have a major impact on a broad spectrum of technological industries such as displays, plastics, soap and detergents, chemicals and petroleum, and pharmaceuticals.

  17. Macromolecular Crowding Studies of Amino Acids Using NMR Diffusion Measurements and Molecular Dynamics Simulations

    Directory of Open Access Journals (Sweden)

    Amninder S Virk

    2015-02-01

    Full Text Available Molecular crowding occurs when the total concentration of macromolecular species in a solution is so high that a considerable proportion of the volume is physically occupied and therefore not accessible to other molecules. This results in significant changes in the solution properties of the molecules in such systems. Macromolecular crowding is ubiquitous in biological systems due to the generally high intracellular protein concentrations. The major hindrance to understanding crowding is the lack of direct comparison of experimental data with theoretical or simulated data. Self-diffusion is sensitive to changes in the molecular weight and shape of the diffusing species, and the available diffusion space (i.e., diffusive obstruction. Consequently, diffusion measurements are a direct means for probing crowded systems including the self-association of molecules. In this work, nuclear magnetic resonance measurements of the self-diffusion of four amino acids (glycine, alanine, valine and phenylalanine up to their solubility limit in water were compared directly with molecular dynamics simulations. The experimental data were then analyzed using various models of aggregation and obstruction. Both experimental and simulated data revealed that the diffusion of both water and the amino acids were sensitive to the amino acid concentration. The direct comparison of the simulated and experimental data afforded greater insights into the aggregation and obstruction properties of each amino acid.

  18. A brief history of macromolecular crystallography, illustrated by a family tree and its Nobel fruits.

    Science.gov (United States)

    Jaskolski, Mariusz; Dauter, Zbigniew; Wlodawer, Alexander

    2014-09-01

    As a contribution to the celebration of the year 2014, declared by the United Nations to be 'The International Year of Crystallography', the FEBS Journal is dedicating this issue to papers showcasing the intimate union between macromolecular crystallography and structural biology, both in historical perspective and in current research. Instead of a formal editorial piece, by way of introduction, this review discusses the most important, often iconic, achievements of crystallographers that led to major advances in our understanding of the structure and function of biological macromolecules. We identified at least 42 scientists who received Nobel Prizes in Physics, Chemistry or Medicine for their contributions that included the use of X-rays or neutrons and crystallography, including 24 who made seminal discoveries in macromolecular sciences. Our spotlight is mostly, but not only, on the recipients of this most prestigious scientific honor, presented in approximately chronological order. As a summary of the review, we attempt to construct a genealogy tree of the principal lineages of protein crystallography, leading from the founding members to the present generation.

  19. Influence of macromolecular architecture on necking in polymer extrusion film casting process

    International Nuclear Information System (INIS)

    Extrusion film casting (EFC) is an important polymer processing technique that is used to produce several thousand tons of polymer films/coatings on an industrial scale. In this research, we are interested in understanding quantitatively how macromolecular chain architecture (for example long chain branching (LCB) or molecular weight distribution (MWD or PDI)) influences the necking and thickness distribution of extrusion cast films. We have used different polymer resins of linear and branched molecular architecture to produce extrusion cast films under controlled experimental conditions. The necking profiles of the films were imaged and the velocity profiles during EFC were monitored using particle tracking velocimetry (PTV) technique. Additionally, the temperature profiles were captured using an IR thermography and thickness profiles were calculated. The experimental results are compared with predictions of one-dimensional flow model of Silagy et al1 wherein the polymer resin rheology is modeled using molecular constitutive equations such as the Rolie-Poly (RP) and extended Pom Pom (XPP). We demonstrate that the 1-D flow model containing the molecular constitutive equations provides new insights into the role of macromolecular chain architecture on film necking.1D. Silagy, Y. Demay, and J-F. Agassant, Polym. Eng. Sci., 36, 2614 (1996)

  20. Oral delivery of macromolecular drugs: Where we are after almost 100years of attempts.

    Science.gov (United States)

    Moroz, Elena; Matoori, Simon; Leroux, Jean-Christophe

    2016-06-01

    Since the first attempt to administer insulin orally in humans more than 90years ago, the oral delivery of macromolecular drugs (>1000g/mol) has been rather disappointing. Although several clinical pilot studies have demonstrated that the oral absorption of macromolecules is possible, the bioavailability remains generally low and variable. This article reviews the formulations and biopharmaceutical aspects of orally administered biomacromolecules on the market and in clinical development for local and systemic delivery. The most successful approaches for systemic delivery often involve a combination of enteric coating, protease inhibitors and permeation enhancers in relatively high amounts. However, some of these excipients have induced local or systemic adverse reactions in preclinical and clinical studies, and long-term studies are often missing. Therefore, strategies aimed at increasing the oral absorption of macromolecular drugs should carefully take into account the benefit-risk ratio. In the absence of specific uptake pathways, small and potent peptides that are resistant to degradation and that present a large therapeutic window certainly represent the best candidates for systemic absorption. While we acknowledge the need for systemically delivering biomacromolecules, it is our opinion that the oral delivery to local gastrointestinal targets is currently more promising because of their accessibility and the lacking requirement for intestinal permeability enhancement. PMID:26826437

  1. An Efficient Low Storage and Memory Treatment of Gridded Interaction Fields for Simulations of Macromolecular Association.

    Science.gov (United States)

    Ozboyaci, Musa; Martinez, Michael; Wade, Rebecca C

    2016-09-13

    Computer simulations of molecular systems often make use of regular rectangular grids with equidistant spacing to store information on their molecular interaction fields, e.g., electrostatic potential. These grids provide an easy way to store the data as they do not require any particular specification of the structure of the data. However, such grids may easily become large, and the storage and memory demands may become so high that calculations become infeasible. To overcome this problem, we show here how the data structure DT-Grid can be adapted and applied to efficiently represent macromolecular interaction grids by exploiting the nonuniformity of information on the grid; at the same time, this data structure ensures fast random data access. We demonstrate use of the DT-Grid data structure for potential of mean force and Brownian dynamics simulations of protein-surface binding and macromolecular association with the SDA software. We further demonstrate that the DT-Grid structure enables systems of large size, such as a viral capsid, and high resolution grids to be handled that are beyond current computational feasibility. PMID:27463233

  2. MxCuBE: a synchrotron beamline control environment customized for macromolecular crystallography experiments.

    Science.gov (United States)

    Gabadinho, José; Beteva, Antonia; Guijarro, Matias; Rey-Bakaikoa, Vicente; Spruce, Darren; Bowler, Matthew W; Brockhauser, Sandor; Flot, David; Gordon, Elspeth J; Hall, David R; Lavault, Bernard; McCarthy, Andrew A; McCarthy, Joanne; Mitchell, Edward; Monaco, Stéphanie; Mueller-Dieckmann, Christoph; Nurizzo, Didier; Ravelli, Raimond B G; Thibault, Xavier; Walsh, Martin A; Leonard, Gordon A; McSweeney, Sean M

    2010-09-01

    The design and features of a beamline control software system for macromolecular crystallography (MX) experiments developed at the European Synchrotron Radiation Facility (ESRF) are described. This system, MxCuBE, allows users to easily and simply interact with beamline hardware components and provides automated routines for common tasks in the operation of a synchrotron beamline dedicated to experiments in MX. Additional functionality is provided through intuitive interfaces that enable the assessment of the diffraction characteristics of samples, experiment planning, automatic data collection and the on-line collection and analysis of X-ray emission spectra. The software can be run in a tandem client-server mode that allows for remote control and relevant experimental parameters and results are automatically logged in a relational database, ISPyB. MxCuBE is modular, flexible and extensible and is currently deployed on eight macromolecular crystallography beamlines at the ESRF. Additionally, the software is installed at MAX-lab beamline I911-3 and at BESSY beamline BL14.1.

  3. Oral delivery of macromolecular drugs: Where we are after almost 100years of attempts.

    Science.gov (United States)

    Moroz, Elena; Matoori, Simon; Leroux, Jean-Christophe

    2016-06-01

    Since the first attempt to administer insulin orally in humans more than 90years ago, the oral delivery of macromolecular drugs (>1000g/mol) has been rather disappointing. Although several clinical pilot studies have demonstrated that the oral absorption of macromolecules is possible, the bioavailability remains generally low and variable. This article reviews the formulations and biopharmaceutical aspects of orally administered biomacromolecules on the market and in clinical development for local and systemic delivery. The most successful approaches for systemic delivery often involve a combination of enteric coating, protease inhibitors and permeation enhancers in relatively high amounts. However, some of these excipients have induced local or systemic adverse reactions in preclinical and clinical studies, and long-term studies are often missing. Therefore, strategies aimed at increasing the oral absorption of macromolecular drugs should carefully take into account the benefit-risk ratio. In the absence of specific uptake pathways, small and potent peptides that are resistant to degradation and that present a large therapeutic window certainly represent the best candidates for systemic absorption. While we acknowledge the need for systemically delivering biomacromolecules, it is our opinion that the oral delivery to local gastrointestinal targets is currently more promising because of their accessibility and the lacking requirement for intestinal permeability enhancement.

  4. Influence of macromolecular architecture on necking in polymer extrusion film casting process

    Energy Technology Data Exchange (ETDEWEB)

    Pol, Harshawardhan; Banik, Sourya; Azad, Lal Busher; Doshi, Pankaj; Lele, Ashish [CSIR-National Chemical Laboratory, Pune, Maharashtra (India); Thete, Sumeet [Purdue University, West Lafayette, Indiana (United States)

    2015-05-22

    Extrusion film casting (EFC) is an important polymer processing technique that is used to produce several thousand tons of polymer films/coatings on an industrial scale. In this research, we are interested in understanding quantitatively how macromolecular chain architecture (for example long chain branching (LCB) or molecular weight distribution (MWD or PDI)) influences the necking and thickness distribution of extrusion cast films. We have used different polymer resins of linear and branched molecular architecture to produce extrusion cast films under controlled experimental conditions. The necking profiles of the films were imaged and the velocity profiles during EFC were monitored using particle tracking velocimetry (PTV) technique. Additionally, the temperature profiles were captured using an IR thermography and thickness profiles were calculated. The experimental results are compared with predictions of one-dimensional flow model of Silagy et al{sup 1} wherein the polymer resin rheology is modeled using molecular constitutive equations such as the Rolie-Poly (RP) and extended Pom Pom (XPP). We demonstrate that the 1-D flow model containing the molecular constitutive equations provides new insights into the role of macromolecular chain architecture on film necking.{sup 1}D. Silagy, Y. Demay, and J-F. Agassant, Polym. Eng. Sci., 36, 2614 (1996)

  5. A NEW UNSTEADY THREE DIMENSIONAL MODEL FOR MACROMOLECULAR TRANSPORT AND WATER FILTRATION ACROSS THE ARTERIAL WALL

    Institute of Scientific and Technical Information of China (English)

    黄浩; 温功碧

    2001-01-01

    A new unsteady three-dimensional convective-diffusive mathematical model for the transportation of macromolecules and water across the arterial wall was proposed . After the formation of leaky junctions due to the mitosis of endothelial cell of the arterial wall, the macromolecular transport happens surrounding the leaky cells. The arterial wall was divided into four layers: the endothelial layer, the subendothelial intima, the internal elastic lamina and the media for the convenience of research. The time-dependent concentration growth,the effect of the shape of endothelial cell and the effect of physiological parameters were analyzed. The analytical solution of velocity field and pressure field of water flow across the arterial wall were obtained; and concentration distribution of three macromolecules ; LDL,HRP and Albumin, were calculated with numerical simulation method. The new theory predicts, the maximum and distribution areas of time dependent concentration with round shape endothelial cell are both larger than that with ellipse-shape endothelial cell. The model also predicts the concentration growth is much alike that of a two-dimensional model and it shows that the concentration reaches its peak at the leaky junction where atherosclerotic formation frequently occurs and falls down rapidly in a limited area beginning from its earlier time growth to the state when macromolecular transfer approaches steadily. These predictions of the new model are in agreement with the experimental observation for the growth and concentration distribution of LDL and Albumin.

  6. A new paradigm for macromolecular crystallography beamlines derived from high-pressure methodology and results

    Energy Technology Data Exchange (ETDEWEB)

    Fourme, Roger, E-mail: roger.fourme@synchrotron-soleil.fr [Synchrotron SOLEIL, BP 48, Saint Aubin, 91192 Gif-sur-Yvette (France); Girard, Eric [IBS (UMR 5075 CEA-CNRS-UJF-PSB), 41 rue Jules Horowitz, 38027 Grenoble Cedex (France); Dhaussy, Anne-Claire [CRISMAT, ENSICAEN, 6 Boulevard du Maréchal Juin, 14000 Caen (France); Medjoubi, Kadda [Synchrotron SOLEIL, BP 48, Saint Aubin, 91192 Gif-sur-Yvette (France); Prangé, Thierry [LCRB (UMR 8015 CNRS), Université Paris Descartes, Faculté de Pharmacie, 4 avenue de l’Observatoire, 75270 Paris (France); Ascone, Isabella [ENSCP (UMR CNRS 7223), 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France); Mezouar, Mohamed [ESRF, BP 220, 38043 Grenoble (France); Kahn, Richard [IBS (UMR 5075 CEA-CNRS-UJF-PSB), 41 rue Jules Horowitz, 38027 Grenoble Cedex (France)

    2011-01-01

    Macromolecular crystallography at high pressure (HPMX) is a mature technique. Shorter X-ray wavelengths increase data collection efficiency on cryocooled crystals. Extending applications and exploiting spin-off of HPMX will require dedicated synchrotron radiation beamlines based on a new paradigm. Biological structures can now be investigated at high resolution by high-pressure X-ray macromolecular crystallography (HPMX). The number of HPMX studies is growing, with applications to polynucleotides, monomeric and multimeric proteins, complex assemblies and even a virus capsid. Investigations of the effects of pressure perturbation have encompassed elastic compression of the native state, study of proteins from extremophiles and trapping of higher-energy conformers that are often of biological interest; measurements of the compressibility of crystals and macromolecules were also performed. HPMX results were an incentive to investigate short and ultra-short wavelengths for standard biocrystallography. On cryocooled lysozyme crystals it was found that the data collection efficiency using 33 keV photons is increased with respect to 18 keV photons. This conclusion was extended from 33 keV down to 6.5 keV by exploiting previously published data. To be fully exploited, the potential of higher-energy photons requires detectors with a good efficiency. Accordingly, a new paradigm for MX beamlines was suggested, using conventional short and ultra-short wavelengths, aiming at the collection of very high accuracy data on crystals under standard conditions or under high pressure. The main elements of such beamlines are outlined.

  7. Errors in macromolecular synthesis after stress : a study of the possible protective role of the small heat shock proteins

    OpenAIRE

    Marin Vinader, L.

    2006-01-01

    The general goal of this thesis was to gain insight in what small heat shock proteins (sHsps) do with respect to macromolecular synthesis during a stressful situation in the cell. It is known that after a non-lethal heat shock, cells are better protected against a subsequent more severe heat shock, a phenomenon known as thermotolerance and attributed to the presence of the heat shock proteins. The question we asked first is whether the error rate in macromolecular synthesis (transcription, RN...

  8. The Study of the Recognizability of Electromagnetic Leakage Information Arising from Computer

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-xin; LU Ying-hua; QIU Yu-chun; CHEN Da-qing

    2004-01-01

    The electromagnetic radiation will result in information leakage when computers work. This paper presents the recognition technology of information leakage caused by video signal electromagnetic radiation. To get the intact and useful information of video signals conveniengtly, the pattern recognition method based on artificial neural networks is proposed. In the last part, the primary word image recovered from the electromagnetic leakage is recognized and reconstructed and the recognizability of the information leakage from computers is discussed.

  9. Perioperative Statin Therapy Is Not Associated With Reduced Risk of Anastomotic Leakage After Colorectal Resection

    DEFF Research Database (Denmark)

    Bisgård, Anne Sofie; Noack, Morten Westergaard; Klein, Mads;

    2013-01-01

    Anastomotic leakage is a serious complication of colorectal surgery. Several studies have demonstrated the beneficial pleiotropic effects of statins, and preliminary studies have suggested that perioperative statin treatment may be associated with reduced risk of anastomotic leakage.......Anastomotic leakage is a serious complication of colorectal surgery. Several studies have demonstrated the beneficial pleiotropic effects of statins, and preliminary studies have suggested that perioperative statin treatment may be associated with reduced risk of anastomotic leakage....

  10. 40 CFR 86.166-12 - Method for calculating emissions due to air conditioning leakage.

    Science.gov (United States)

    2010-07-01

    ... to air conditioning leakage. 86.166-12 Section 86.166-12 Protection of Environment ENVIRONMENTAL... for calculating emissions due to air conditioning leakage. This section describes procedures used to determine a refrigerant leakage rate in grams per year from vehicle-based air conditioning units....

  11. Detection and quantification of methane leakage from landfills

    Energy Technology Data Exchange (ETDEWEB)

    Ljungberg, Sven-Aake; Maartensson, Stig-Goeran (Univ. of Gaevle, Gaevle (Sweden)); Meijer, Jan-Erik; Rosqvist, Haakan (NSR AB, Helsingborg (Sweden))

    2009-03-15

    The purpose of this project was to detect gas leakage and to measure and quantify methane emission from landfills using modern remote sensing techniques. In this project, a handheld laser instrument and an IR camera were used. The overall objective was to develop cost-effective methods for detecting and quantifying methane emissions from landfills. There are many methods available for measuring the methane concentration in air, both from close-up and from long distances. Combined with the use of a tracer gas, the methane emission from entire landfills can be measured relatively accurately. A number of methods are used to detect leakage from parts of landfill surfaces, but there are few methods for quantifying leakage from sub-zones. Field measurements with the laser instrument and the IR camera were carried out at seven Swedish landfills and two landfills in France. The investigated surfaces at the Swedish landfills were divided into different zones, such as top surface, slope, crest and toe of slope. The field measurements in France were taken over entire landfills. The methane emission varied between the different landfills in the project, and also between the different landfill zones. The results from repeated field measurements indicated that a landfill with a final cap and a successful gas recovery system produces barely measurable emissions. The weak points at a landfill are generally slopes, including crests and toes of slopes. Where the covering of the waste is inadequate, leakage often occurs at lift joints and in areas where waste protrudes through the cover. Other weak points are deficiencies in the gas recovery system. Leachate systems can lead landfill gas and thereby cause methane leakage. Along with wind velocity and variations in atmospheric pressure, moisture content in the ground is an important factor that affects methane emissions from landfill surfaces. Results from field measurements of the same feature/surface at different points in time and

  12. Model-Based Detection of Pipe Leakage at Joints

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Taejin; Youn, Byeng D.; Woo, Sihyong [Seoul National University, Seoul (Korea, Republic of)

    2015-03-15

    Time domain reflectometry (TDR) is widely used for wire failure detection. It transmits a pulse that is reflected at the boundaries of different characteristic impedances. By analyzing the reflected signal, TDR makes it possible to locate the failure. In this study, TDR was used to detect the water leakage at a pipe joint. A wire attached to the pipe surface was soaked by water when a leak occurred, which affected the characteristic impedance of the wet part, resulting in a change in the reflected signal. To infer the leakage from the TDR signal, we first developed a finite difference time domain-based forward model that provided the output of the TDR signal given the configuration of the transmission line. Then, by solving the inverse problem, the locations of the leaks were found.

  13. Mission analysis report for single-shell tank leakage mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Cruse, J.M.

    1994-09-01

    This document provides an analysis of the leakage mitigation mission applicable to past and potential future leakage from the Hanford Site`s 149 single-shell high-level waste tanks. This mission is a part of the overall missions of the Westinghouse Hanford Company Tank Waste Remediation System division to remediate the tank waste in a safe and acceptable manner. Systems engineers principles are being applied to this effort. Mission analysis supports early decision making by clearly defining program objectives. This documents identifies the initial conditions and acceptable final conditions, defines the programmatic and physical interfaces and constraints, estimates the resources to carry out the mission, and establishes measures of success. The results of the mission analysis provide a consistent basis for subsequent systems engineering work.

  14. A software sampling frequency adaptive algorithm for reducing spectral leakage

    Institute of Scientific and Technical Information of China (English)

    PAN Li-dong; WANG Fei

    2006-01-01

    Spectral leakage caused by synchronous error in a nonsynchronous sampling system is an important cause that reduces the accuracy of spectral analysis and harmonic measurement.This paper presents a software sampling frequency adaptive algorithm that can obtain the actual signal frequency more accurately,and then adjusts sampling interval base on the frequency calculated by software algorithm and modifies sampling frequency adaptively.It can reduce synchronous error and impact of spectral leakage;thereby improving the accuracy of spectral analysis and harmonic measurement for power system signal where frequency changes slowly.This algorithm has high precision just like the simulations show,and it can be a practical method in power system harmonic analysis since it can be implemented easily.

  15. Support calculations for management of PRISE leakage accidents

    Energy Technology Data Exchange (ETDEWEB)

    Matejovic, P.; Vranka, L. [Nuclear Power Plants Research Inst. Vuje, Trnava (Slovakia)

    1997-12-31

    Accidents involving primary-to-secondary leakage (PRISE) caused by rupture of one or a few tubes are well known design basis events in both, western and VVER NPPs. Operating experience and in-service inspections of VVER-440 units have demonstrated also the potential for large PRISE leaks in the case of the steam generator (SG) primary collector cover lift-up (Rovno NPP). Without performing any countermeasure for limitation of SG collector cover lift-up, a full opening results in PRISE leak with an equivalent diameter 107 mm. Although this accident was not considered in the original design, this event is usually analysed as DBA too. Different means are available for detection and mitigation of PRISE leakage in NPPs currently in operation (J.Bohunice V-1 and V-2) or under construction (Mochovce) in Slovakia. 8 refs.

  16. Correlation among ESDD, NSDD and leakage current in distribution insulators

    International Nuclear Information System (INIS)

    The maintenance of distribution networks is more effective if the insulation contamination levels are known. The selection of measuring methods of pollution levels is then crucial. The relationship between several evaluation methods of pollution levels and the operating behaviour of several insulator profiles in a polluted zone is described. Laboratory tests were carried out to reproduce pollution levels found in the field. The quantity of non-soluble materials deposited over the insulators' surface affect the magnitude of the leakage current generated over a contaminated insulator. The relationship that defines leakage current with respect to the equivalent salt deposit density (ESDD) level for a specific non-soluble material level is almost linear, from which it is possible to develop a relationship between them for each insulator. (author)

  17. Airbag for the closing of pipelines on explosions and leakages

    DEFF Research Database (Denmark)

    Eisenreich, N.; Neutz, J.; Seiler, F.;

    2007-01-01

    was the idea to use airbags similar to those utilized in cars. Two pipeline applications were taken into consideration: a low-pressure module able to suppress explosion propagation and a high-pressure module to stop leakages from, e.g. natural gas pipeline capable to be used for duct diameters up to 0.6 m......This paper is a result of international effort aimed at the construction of a device for quick closing of pipelines in the case of explosion propagation and/or chemical leakage. Such a problem exists in industries where flammable substances are transported by pipelines. The basic solution principle...... into a pipe flow and analysis of the bag shapes was also completed. Two gas generators were constructed and tested with novel propellant materials. Different airbag models were tested to evaluate their effectiveness. Risk analysis approach was applied to evaluate the safety and economic benefits of the new...

  18. The root caused analysis of leakaged heat exchanger tube

    International Nuclear Information System (INIS)

    AISI type 316L stainless steel was used as a heat exchanger tube material in an inter-cooler column. After less than a year of operation, severe corrosion failures occurred and a transverse opening leakage was observed on one of the heat exchanger tubes. The failed tube was carefully analyzed using various metallurgical laboratory equipments. The root cause of the tube leakage was believed due to the presence of horizontal micro and macro pores as a hydrogen gas entrapment during casting of the parent ingot. The overlapped and gaping pores formed notch on the shell side of the tube surface, and it increasingly evident when the use of a high-energy water-jet and metal brush as cleaning procedure results in an establishment of pitting type local-action corrosion cells penetrated the tube wall. As a result, corrosive fluid in the tube side dissolved into the cooling water, accelerating the corrosion process.

  19. An advanced leakage scheme for neutrino treatment in astrophysical simulations

    CERN Document Server

    Perego, Albino; Käppeli, Roger

    2015-01-01

    We present an Advanced Spectral Leakage (ASL) scheme to model neutrinos in the context of core-collapse supernovae and compact binary mergers. Based on previous gray leakage schemes, the ASL scheme computes the neutrino cooling rates by interpolating local production and diffusion rates (relevant in optically thin and thick regimes, respectively), separately for discretized values of the neutrino energy. Neutrino trapped components are also modeled, based on equilibrium and timescale arguments. The better accuracy achieved by the spectral treatment allows a more reliable computation of neutrino heating rates in optically thin conditions. The scheme has been calibrated and tested against Boltzmann transport in the context of Newtonian spherically symmetric models of core-collapse supernovae. ASL shows a very good qualitative and a partial quantitative agreement, for key quantities from collapse to a few hundreds of milliseconds after core bounce. We have proved the adaptability and flexibility of our ASL schem...

  20. Turbocharger with sliding piston, and having vanes and leakage dams

    Science.gov (United States)

    Roberts, Quentin; Alnega, Ahmed

    2011-12-06

    A turbocharger having a sliding piston for regulating exhaust gas flow into the turbine wheel includes a set of first vanes mounted on a fixed first wall of the turbine nozzle and projecting axially toward an opposite second wall of the nozzle, and/or a set of second vanes mounted on the end of the piston and projecting in an opposite axial direction toward the first wall of the nozzle. For the/each set of vanes, there are leakage dams formed on the wall that is adjacent the vane tips when the piston is closed. The leakage dams are closely adjacent the vane tips and discourage exhaust gas from leaking in a generally radial direction past the vane tips as the piston just begins to open from its fully closed position.

  1. Impact of the Indonesian Throughflow on Agulhas leakage

    Directory of Open Access Journals (Sweden)

    D. Le Bars

    2013-09-01

    Full Text Available Using ocean models of different complexity we show that opening the Indonesian Passage between the Pacific and the Indian oceans increases the input of Indian Ocean water into the South Atlantic via the Agulhas leakage. In a strongly eddying global ocean model this response results from an increased Agulhas Current transport and a constant proportion of Agulhas retroflection south of Africa. The leakage increases through an increased frequency of ring shedding events. In an idealized two-layer and flat-bottom eddy resolving model, the proportion of the Agulhas Current transport that retroflects is (for a wide range of wind stress forcing not affected by an opening of the Indonesian Passage. Using a comparison with a linear model and previous work on the retroflection problem, the result is explained as a balance between two mechanisms: decrease retroflection due to large-scale momentum balance and increase due to local barotropic/baroclinic instabilities.

  2. Geochemical implications of brine leakage into freshwater aquifers.

    Science.gov (United States)

    Wunsch, Assaf; Navarre-Sitchler, Alexis K; McCray, John E

    2013-01-01

    CO(2) injection into deep saline formations as a way to mitigate climate change raises concerns that leakage of saline waters from the injection formations will impact water quality of overlying aquifers, especially underground sources of drinking water (USDWs). This paper aims to characterize the geochemical composition of deep brines, with a focus on constituents that pose a human health risk and are regulated by the U.S. Environmental Protection Agency (USEPA). A statistical analysis of the NATCARB brine database, combined with simple mixing model calculations, show total dissolved solids and concentrations of chloride, boron, arsenic, sulfate, nitrate, iron and manganese may exceed plant tolerance or regulatory levels. Twelve agricultural crops evaluated for decreased productivity in the event of brine leakage would experience some yield reduction due to increased TDS at brine-USDW ratios of United States are almost three times higher than public and domestic withdrawals.

  3. Robust Strategy for Intake Leakage Detection in Diesel Engines

    OpenAIRE

    Ceccarelli, Riccardo; Moulin, Philippe; Canudas De Wit, Carlos

    2009-01-01

    International audience Fault detection is motivated by the needs of guaranteeing high-performance engine behavior and regarding to the environmentally-based legislative regulations. An adaptive model based observer strategy is applied for the fault detection and estimation. The hole estimation relies on the model accuracy and sensors precision. In this paper is provided by a model-based upper bound for leakage error estimation for threshold design by the mean of the observer sensitivity st...

  4. Bacterial coronal leakage after obturation with three root canal sealers.

    Science.gov (United States)

    Timpawat, S; Amornchat, C; Trisuwan, W R

    2001-01-01

    The purpose of this study was to compare the bacterial leakage of root canals obturated with three root canal sealers, using Endodontalis faecalis as a microbial tracer to determine the length of time for bacteria to penetrate through the obturated root canal to the root apex. Seventy-five, single-rooted teeth with straight root canals had the crown cut off at the cementoenamel junction. Root canals were instrumented by a step-back technique. The prepared teeth were randomly divided into 3 groups of 19 teeth each and another 2 groups as positive and negative controls (9 teeth each). The experimental groups were dependent on the sealer used: AH-Plus, Apexit, and Ketac-Endo. The root canals were obturated using a lateral condensation technique. After 24 h the teeth were attached to microcentrifuge tubes with 2 mm of the root apex submerged in Brain Heart Infusion broth in glass test tubes. The coronal portions of the root canal filling materials were placed in contact with E. faecalis. The teeth were observed for bacterial leakage daily for 30 and 60 days. With the chi2 test for comparing pairs of groups at the 0.05 level (p 0.06), but Apexit had significantly higher leakage (p 0.05), but Apexit leaked more than AH-Plus. The conclusion drawn from this experiment was that epoxy resin root canal sealer was found to be more adaptable to the root canal wall and filling material than a calcium hydroxide sealer when bacterial coronal leakage was studied.

  5. Giant mid-esophageal diverticulum. Conservative treatment of postoperative leakage.

    Science.gov (United States)

    Dallatomasina, S; Casaccia, M; Chessa, M; Serrano, J; Nardi, I; Troilo, B; Miggino, M; Valente, U

    2009-01-01

    Mid-esophageal diverticula are rare entities. Only symptomatic patients usually receive surgical treatment. Esophageal leakage is one of the most common complications after these procedures. Though in literature, operative management is the preferred treatment for esophageal fistula, conservative approach is described in case of small leaks. We report a case of an operated giant mid-esophageal diverticulum complicated with an esophageal fistula. The patient underwent a surgical treatment and recovered completely.

  6. Management of excluded segmental bile duct leakage following liver resection

    Science.gov (United States)

    Honoré, Charles; Vibert, Eric; Hoti, Emir; Azoulay, Daniel; Adam, René; Castaing, Denis

    2009-01-01

    Background: Postoperative bile leak secondary to a fistula is a known complication of hepatic surgery. Four different biliary fistula sub-types have been described: type A refers to minor leakage from the bile duct stump; type B to major leakage caused by insufficient closure of the bile duct stump; type C to major leakage caused by injury to the bile duct, and type D (the rarest) to the division and exclusion of a bile duct. This complication results from functional liver parenchyma in which bile drainage is excluded from the main duct. Methods: A retrospective review of the database for 163 patients diagnosed with post-hepatic surgery bile leak from April 1992 to June 2007 was performed. Results: Three patients were found to have type D biliary fistula, with durations of 3–21 months. The bile leak developed after a right hepatectomy in two patients and a right hepatectomy extending to segment IV in one patient. All three patients were rescheduled for surgical exploration, following failure of medical treatment. The procedure consisted of repeat resection of the independent liver parenchyma containing the fistula. One patient developed a postoperative leak from a hepaticojejunal anastomosis (treated conservatively) and the other two patients had an uneventful recovery. No recurrence of bile leak was encountered during their follow-up. Conclusions: Our experience indicates that conservative treatment is deceptive and not efficacious. For this condition, surgical intervention is the treatment of choice because it is very effective and is associated with a low morbidity. PMID:19718366

  7. A Minimum Leakage Quasi-Static RAM Bitcell

    Directory of Open Access Journals (Sweden)

    Adam Teman

    2011-05-01

    Full Text Available As SRAMs continue to grow and comprise larger percentages of the area and power consumption in advanced systems, the need to minimize static currents becomes essential. This brief presents a novel 9T Quasi-Static RAM Bitcell that provides aggressive leakage reduction and high write margins. The quasi-static operation method of this cell, based on internal feedback and leakage ratios, minimizes static power while maintaining sufficient, albeit depleted, noise margins. This paper presents the concept of the novel cell, and discusses the stability of the cell under hold, read and write operations. The cell was implemented in a low-power 40 nm TSMC process, showing as much as a 12× reduction in leakage current at typical conditions, as compared to a standard 6T or 8T bitcell at the same supply voltage. The implemented cell showed full functionality under global and local process variations at nominal and low voltages, as low as 300 mV.

  8. Surface Leakage Mechanisms in III-V Infrared Barrier Detectors

    Science.gov (United States)

    Sidor, D. E.; Savich, G. R.; Wicks, G. W.

    2016-09-01

    Infrared detector epitaxial structures employing unipolar barriers exhibit greatly reduced dark currents compared to simple pn-based structures. When correctly positioned within the structure, unipolar barriers are highly effective at blocking bulk dark current mechanisms. Unipolar barriers are also effective at suppressing surface leakage current in infrared detector structures employing absorbing layers that possess the same conductivity type in their bulk and at their surface. When an absorbing layer possesses opposite conductivity types in its bulk and at its surface, unipolar barriers are not solutions to surface leakage. This work reviews empirically determined surface band alignments of III-V semiconductor compounds and modeled surface band alignments of both gallium-free and gallium-containing type-II strained layer superlattice material systems. Surface band alignments are used to predict surface conductivity types in several detector structures, and the relationship between surface and bulk conductivity types in the absorbing layers of these structures is used as the basis for explaining observed surface leakage characteristics.

  9. Indoor-Outdoor Air Leakage of Apartments and Commercial Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Price, P.N.; Shehabi, A.; Chan, R.W.; Gadgil, A.J.

    2006-06-01

    We compiled and analyzed available data concerning indoor-outdoor air leakage rates and building leakiness parameters for commercial buildings and apartments. We analyzed the data, and reviewed the related literature, to determine the current state of knowledge of the statistical distribution of air exchange rates and related parameters for California buildings, and to identify significant gaps in the current knowledge and data. Very few data were found from California buildings, so we compiled data from other states and some other countries. Even when data from other developed countries were included, data were sparse and few conclusive statements were possible. Little systematic variation in building leakage with construction type, building activity type, height, size, or location within the u.s. was observed. Commercial buildings and apartments seem to be about twice as leaky as single-family houses, per unit of building envelope area. Although further work collecting and analyzing leakage data might be useful, we suggest that a more important issue may be the transport of pollutants between units in apartments and mixed-use buildings, an under-studied phenomenon that may expose occupants to high levels of pollutants such as tobacco smoke or dry cleaning fumes.

  10. Air Leakage and Air Transfer Between Garage and Living Space

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, Armin [Building Science Corporation, Westford, MA (United States)

    2014-09-01

    This research project focused on evaluation of air transfer between the garage and living space in a single-family detached home constructed by a production homebuilder in compliance with the 2009 International Residential Code and the 2009 International Energy Conservation Code. The project gathered important information about the performance of whole-building ventilation systems and garage ventilation systems as they relate to minimizing flow of contaminated air from garage to living space. A series of 25 multi-point fan pressurization tests and additional zone pressure diagnostic testing characterized the garage and house air leakage, the garage-to-house air leakage, and garage and house pressure relationships to each other and to outdoors using automated fan pressurization and pressure monitoring techniques. While the relative characteristics of this house may not represent the entire population of new construction configurations and air tightness levels (house and garage) throughout the country, the technical approach was conservative and should reasonably extend the usefulness of the results to a large spectrum of house configurations from this set of parametric tests in this one house. Based on the results of this testing, the two-step garage-to-house air leakage test protocol described above is recommended where whole-house exhaust ventilation is employed.

  11. Leakage Current Characteristics of Pre-flashover Along Ice-covered Insulator String%Leakage Current Characteristics of Pre-flashover Along Ice-covered Insulator String

    Institute of Scientific and Technical Information of China (English)

    LI Zhou; ZHANG Qiao-gen; LIU Feng-lian; JIA Hui-dong; XI Hai-bo

    2011-01-01

    Flashover of ice-covered in power grid. As leakage current suspension insulator string is one of the is one of the important characteristics to major problems for the transmission lines predict the flashover of suspension insulator string, measuring method and analysis of the leakage current are developed for ice-covered XWP2-160 porcelain suspension insulator string in this paper. The waveform of the leakage current is perfectly recorded from the occurrence of micro-discharge to flashover, in which the process can be divided into four periods according to the evolution of the leakage current. There are different rising rates of the leakage current and various phenomena of arc discharge in different periods with the increase of the applied voltage, and the distortion on the leakage current waveform is detected because of the effect of arc discharge. A characteristic current (Iw)and a critical current (IFT)of flashover, two important parameters of the leakage current before ice-covered insulator string flashover, are defined for analysis of the leakage current characteristics of pre-flashover along the polluted insulator string covered with ice. Statistical experimental results show that the average values of Iw and IFT are within the major distribution zones, and both currents can be used for predicting the icing flashover. The values of two important leakage currents are approximately constant at different contamination degrees, while the direct relationships between the critical currents and the contamination degrees are not found in this paper.

  12. Errors in macromolecular synthesis after stress : a study of the possible protective role of the small heat shock proteins

    NARCIS (Netherlands)

    Marin Vinader, L.

    2006-01-01

    The general goal of this thesis was to gain insight in what small heat shock proteins (sHsps) do with respect to macromolecular synthesis during a stressful situation in the cell. It is known that after a non-lethal heat shock, cells are better protected against a subsequent more severe heat shock,

  13. Proceedings of a one-week course on exploiting anomalous scattering in macromolecular structure determination (EMBO'07)

    International Nuclear Information System (INIS)

    This course, which was directed to young scientists, illustrated both theoretical and practical aspects of macromolecular crystal structure solution using synchrotron radiation. Some software dedicated to data collection, processing and analysis were presented. This document gathers only the slides of the presentations

  14. Macromolecular crowding meets oxygen tension in human mesenchymal stem cell culture - A step closer to physiologically relevant in vitro organogenesis

    Science.gov (United States)

    Cigognini, Daniela; Gaspar, Diana; Kumar, Pramod; Satyam, Abhigyan; Alagesan, Senthilkumar; Sanz-Nogués, Clara; Griffin, Matthew; O’Brien, Timothy; Pandit, Abhay; Zeugolis, Dimitrios I.

    2016-08-01

    Modular tissue engineering is based on the cells’ innate ability to create bottom-up supramolecular assemblies with efficiency and efficacy still unmatched by man-made devices. Although the regenerative potential of such tissue substitutes has been documented in preclinical and clinical setting, the prolonged culture time required to develop an implantable device is associated with phenotypic drift and/or cell senescence. Herein, we demonstrate that macromolecular crowding significantly enhances extracellular matrix deposition in human bone marrow mesenchymal stem cell culture at both 20% and 2% oxygen tension. Although hypoxia inducible factor - 1α was activated at 2% oxygen tension, increased extracellular matrix synthesis was not observed. The expression of surface markers and transcription factors was not affected as a function of oxygen tension and macromolecular crowding. The multilineage potential was also maintained, albeit adipogenic differentiation was significantly reduced in low oxygen tension cultures, chondrogenic differentiation was significantly increased in macromolecularly crowded cultures and osteogenic differentiation was not affected as a function of oxygen tension and macromolecular crowding. Collectively, these data pave the way for the development of bottom-up tissue equivalents based on physiologically relevant developmental processes.

  15. Force Spectroscopy of Individual Stimulus-Responsive Poly(ferrocenyldimethylsilane) Chains: Towards a Redox-Driven Macromolecular Motor

    NARCIS (Netherlands)

    Zou, Shan; Hempenius, Mark A.; Schönherr, Holger; Vancso, G. Julius

    2006-01-01

    Progress in the development of a redox-driven macromolecular motor and the characterization of its redox-mechanical cycle using electrochemical AFM-based single-molecule force spectroscopy (SMFS) is described. The elasticities of individual neutral and oxidized poly(ferrocenyldimethylsilane) (PFS) m

  16. Proceedings of a one-week course on exploiting anomalous scattering in macromolecular structure determination (EMBO'07)

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, M.S.; Shepard, W.; Dauter, Z.; Leslie, A.; Diederichs, K.; Evans, G.; Svensson, O.; Schneider, T.; Bricogne, G.; Dauter, Z.; Flensburg, C.; Terwilliger, T.; Lamzin, V.; Leslie, A.; Kabsch, W.; Flensburg, C.; Terwilliger, T.; Lamzin, V.; Read, R.; Panjikar, S.; Pannu, N.S.; Dauter, Z.; Weiss, M.S.; McSweeney, S

    2007-07-01

    This course, which was directed to young scientists, illustrated both theoretical and practical aspects of macromolecular crystal structure solution using synchrotron radiation. Some software dedicated to data collection, processing and analysis were presented. This document gathers only the slides of the presentations.

  17. Effect of STI-induced mechanical stress on leakage current in deep submicron CMOS devices

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The shallow trench isolation (STI) induced mechanical stress significantly affects the CMOS device off-state leakage behaviour. In this paper, we designed two types of devices to investigate this effect, and all leakage components,including sub-threshold leakage (Isub), gate-induced-drain-leakage (IGIDL), gate edge-direct-tunnelling leakage (IEDT) and band-to-band-tunnelling leakage (IBTBT) were analysed. For NMOS, Isub can be reduced due to the mechanical stress induced higher boron concentration in well region. However, the GIDL component increases simultaneously as a result of the high well concentration induced drain-to-well depletion layer narrowing as well as the shrinkage of the energy gap. For PMOS, the only mechanical stress effect on leakage current is the energy gap narrowing induced GIDL increase.

  18. A mixed method for measuring low-frequency acoustic properties of macromolecular materials

    Institute of Scientific and Technical Information of China (English)

    LIU; Hongwei; YAO; Lei; ZHAO; Hong; ZHANG; Jichuan; XUE; Zhaohong

    2006-01-01

    A mixed method for measuring low-frequency acoustic properties of macromolecular materials is presented.The dynamic mechanical parameters of materials are first measured by using Dynamic Mechanical Thermal Apparatus(DMTA) at low frequencies,usually less than 100 Hz; then based on the Principles of Time-Temperature Super position (TTS),these parameters are extended to the frequency range that acousticians are concerned about,usually from hundreds to thousands of hertz; finally the extended dynamic mechanical parameters are transformed into acoustic parameters with the help of acoustic measurement and inverse analysis.To test the feasibility and accuracy,we measure a kind of rubber sample in DMTA and acquire the basic acoustic parameters of the sample by using this method.While applying the basic parameters to calculating characteristics of the sample in acoustic pipe,a reasonable agreement of sound absorption coefficients is obtained between the calculations and measurements in the acoustic pipe.

  19. A vibrating membrane bioreactor (VMBR): Macromolecular transmission-influence of extracellular polymeric substances

    DEFF Research Database (Denmark)

    Beier, Søren; Jonsson, Gunnar Eigil

    2009-01-01

    The vibrating membrane bioreactor (VMBR) system facilitates the possibility of conducting a separation of macromolecules (BSA) from larger biological components (yeast cells) with a relatively high and stable macromolecular transmission at sub-critical flux. This is not possible to achieve...... for a static non-vibrating membrane module. A BSA transmission of 74% has been measured in the separation of 4g/L BSA from 8 g/L dry weight yeast cells in suspension at sub-critical flux (20L/(m(2) h)). However, this transmission is lower than the 85% BSA transmission measured for at pure 4g/L BSA solution...... of around 32% is measured for a pure yeast cell suspension. Thus, EPS and BSA are "competing" in being transmitted which might explain the lowered BSA transmission in the presence of yeast cells. Additionally, EPS heavily foul the membranes, leading to a 86% permeability drop and a fouling resistance 6...

  20. Whole Cell Imprinting in Sol-Gel Thin Films for Bacterial Recognition in Liquids: Macromolecular Fingerprinting

    Directory of Open Access Journals (Sweden)

    Robert Armon

    2010-03-01

    Full Text Available Thin films of organically modified silica (ORMOSILS produced by a sol-gel method were imprinted with whole cells of a variety of microorganisms in order to develop an easy and specific probe to concentrate and specifically identify these microorganisms in liquids (e.g., water. Microorganisms with various morphology and outer surface components were imprinted into thin sol-gel films. Adsorption of target microorganism onto imprinted films was facilitated by these macromolecular fingerprints as revealed by various microscopical examinations (SEM, AFM, HSEM and CLSM. The imprinted films showed high selectivity toward each of test microorganisms with high adsorption affinity making them excellent candidates for rapid detection of microorganisms from liquids.

  1. Polymer segregation under confinement: Influences of macromolecular crowding and the interaction between the polymer and crowders

    Science.gov (United States)

    Chen, Yuhao; Yu, Wancheng; Wang, Jiajun; Luo, Kaifu

    2015-10-01

    Entropy driven polymer segregation in confinements as a model for chromosome separation in bacteria has attracted wide attention; however, the effects of macromolecular crowding and the interaction between the binding protein and the newly replicated DNA on the segregation dynamics are not clear. Using Langevin dynamics simulations, we investigate the influences of crowders and the attractive interaction between the polymer and a small number of crowders on segregation of two overlapping polymers under a cylindrical confinement. We find that the segregation time increases with increasing the volume fraction of crowders due to the slower chain diffusion in crowded environments. For a fixed volume fraction of crowders, the segregation time decreases with increasing the size of crowders. Moreover, the attractive interaction between the polymer and a small number of crowders can significantly facilitate the chain segregation. These results are important for understanding the chromosome segregation in living cells.

  2. Proteome-wide dataset supporting the study of ancient metazoan macromolecular complexes

    Directory of Open Access Journals (Sweden)

    Sadhna Phanse

    2016-03-01

    Full Text Available Our analysis examines the conservation of multiprotein complexes among metazoa through use of high resolution biochemical fractionation and precision mass spectrometry applied to soluble cell extracts from 5 representative model organisms Caenorhabditis elegans, Drosophila melanogaster, Mus musculus, Strongylocentrotus purpuratus, and Homo sapiens. The interaction network obtained from the data was validated globally in 4 distant species (Xenopus laevis, Nematostella vectensis, Dictyostelium discoideum, Saccharomyces cerevisiae and locally by targeted affinity-purification experiments. Here we provide details of our massive set of supporting biochemical fractionation data available via ProteomeXchange (PXD002319-PXD002328, PPIs via BioGRID (185267; and interaction network projections via (http://metazoa.med.utoronto.ca made fully accessible to allow further exploration. The datasets here are related to the research article on metazoan macromolecular complexes in Nature [1].

  3. Proteome-wide dataset supporting the study of ancient metazoan macromolecular complexes.

    Science.gov (United States)

    Phanse, Sadhna; Wan, Cuihong; Borgeson, Blake; Tu, Fan; Drew, Kevin; Clark, Greg; Xiong, Xuejian; Kagan, Olga; Kwan, Julian; Bezginov, Alexandr; Chessman, Kyle; Pal, Swati; Cromar, Graham; Papoulas, Ophelia; Ni, Zuyao; Boutz, Daniel R; Stoilova, Snejana; Havugimana, Pierre C; Guo, Xinghua; Malty, Ramy H; Sarov, Mihail; Greenblatt, Jack; Babu, Mohan; Derry, W Brent; Tillier, Elisabeth R; Wallingford, John B; Parkinson, John; Marcotte, Edward M; Emili, Andrew

    2016-03-01

    Our analysis examines the conservation of multiprotein complexes among metazoa through use of high resolution biochemical fractionation and precision mass spectrometry applied to soluble cell extracts from 5 representative model organisms Caenorhabditis elegans, Drosophila melanogaster, Mus musculus, Strongylocentrotus purpuratus, and Homo sapiens. The interaction network obtained from the data was validated globally in 4 distant species (Xenopus laevis, Nematostella vectensis, Dictyostelium discoideum, Saccharomyces cerevisiae) and locally by targeted affinity-purification experiments. Here we provide details of our massive set of supporting biochemical fractionation data available via ProteomeXchange (PXD002319-PXD002328), PPIs via BioGRID (185267); and interaction network projections via (http://metazoa.med.utoronto.ca) made fully accessible to allow further exploration. The datasets here are related to the research article on metazoan macromolecular complexes in Nature [1]. PMID:26870755

  4. Rasta silanes: new silyl resins with novel macromolecular architecture via living free radical polymerization

    Science.gov (United States)

    Lindsley; Hodges; Filzen; Watson; Geyer

    2000-09-01

    Heating TEMPO-methyl resin with dialkylsilane styrenes affords larger resin beads via living free radical polymerization. The new silyl resins prepared by this solvent-free suspension polymerization protocol have been coined "Rasta silanes". Rasta silanes have a novel macromolecular architecture typified by long straight chain polymers bearing the silanes which emanate from the phenyl rings of a cross-linked polystyrene core. By careful selection of comonomers during the polymerization step, loading capacity, silane spacing, and the relative distance of the silane moieties from the resin core can be controlled. The consistently high-loading Rasta silane resins produced can be easily converted into either a reactive silyl chloride or triflate to subsequently anchor alcohols and phenols to the solid phase. Cleavage from the resin can be mediated by treatment with HF.pyridine, TFA solutions, or TBAF.

  5. Computational Methodologies for Real-Space Structural Refinement of Large Macromolecular Complexes.

    Science.gov (United States)

    Goh, Boon Chong; Hadden, Jodi A; Bernardi, Rafael C; Singharoy, Abhishek; McGreevy, Ryan; Rudack, Till; Cassidy, C Keith; Schulten, Klaus

    2016-07-01

    The rise of the computer as a powerful tool for model building and refinement has revolutionized the field of structure determination for large biomolecular systems. Despite the wide availability of robust experimental methods capable of resolving structural details across a range of spatiotemporal resolutions, computational hybrid methods have the unique ability to integrate the diverse data from multimodal techniques such as X-ray crystallography and electron microscopy into consistent, fully atomistic structures. Here, commonly employed strategies for computational real-space structural refinement are reviewed, and their specific applications are illustrated for several large macromolecular complexes: ribosome, virus capsids, chemosensory array, and photosynthetic chromatophore. The increasingly important role of computational methods in large-scale structural refinement, along with current and future challenges, is discussed. PMID:27145875

  6. OCTOPUS: an innovative multimodal diffractometer for neutron macromolecular crystallography across the length scales

    International Nuclear Information System (INIS)

    We propose to construct a novel protein diffractometer at position H112B. The new instrument will deliver major efficiency gains, as well as offering greatly extended flexibility through the option of several easily interchangeable modes of operation. This proposal builds on the demonstrable need to extend ILL's capacity for high resolution structural studies of protein systems, as well as a need to widen the scope of biological crystallography - in particular for monochromatic studies at both high and low resolution. The development will be carried out in close collaboration with structural biologists at the ESRF, and engineered in such a way that the user interface of the instrument (from sample to software) will be transparently identifiable to a large, dynamic, and driven community of European synchrotron X-ray macromolecular crystallographers. (authors)

  7. Phenix - a comprehensive python-based system for macromolecular structure solution

    Energy Technology Data Exchange (ETDEWEB)

    Terwilliger, Thomas C [Los Alamos National Laboratory; Hung, Li - Wei [Los Alamos National Laboratory; Adams, Paul D [UC BERKELEY; Afonine, Pavel V [UC BERKELEY; Bunkoczi, Gabor [UNIV OF CAMBRIDGE; Chen, Vincent B [DUKE UNIV; Davis, Ian [DUKE UNIV; Echols, Nathaniel [LBNL; Headd, Jeffrey J [DUKE UNIV; Grosse Kunstleve, Ralf W [LBNL; Mccoy, Airlie J [UNIV OF CAMBRIDGE; Moriarty, Nigel W [LBNL; Oeffner, Robert [UNIV OF CAMBRIDGE; Read, Randy J [UNIV OF CAMBRIDGE; Richardson, David C [DUKE UNIV; Richardson, Jane S [DUKE UNIV; Zwarta, Peter H [LBNL

    2009-01-01

    Macromolecular X-ray crystallography is routinely applied to understand biological processes at a molecular level. However, significant time and effort are still required to solve and complete many of these structures because of the need for manual interpretation of complex numerical data using many software packages, and the repeated use of interactive three-dimensional graphics. Phenix has been developed to provide a comprehensive system for crystallographic structure solution with an emphasis on automation of all procedures. This has relied on the development of algorithms that minimize or eliminate subjective input, the development of algorithms that automate procedures that are traditionally performed by hand, and finally the development of a framework that allows a tight integration between the algorithms.

  8. Integration and global analysis of isothermal titration calorimetry data for studying macromolecular interactions.

    Science.gov (United States)

    Brautigam, Chad A; Zhao, Huaying; Vargas, Carolyn; Keller, Sandro; Schuck, Peter

    2016-05-01

    Isothermal titration calorimetry (ITC) is a powerful and widely used method to measure the energetics of macromolecular interactions by recording a thermogram of differential heating power during a titration. However, traditional ITC analysis is limited by stochastic thermogram noise and by the limited information content of a single titration experiment. Here we present a protocol for bias-free thermogram integration based on automated shape analysis of the injection peaks, followed by combination of isotherms from different calorimetric titration experiments into a global analysis, statistical analysis of binding parameters and graphical presentation of the results. This is performed using the integrated public-domain software packages NITPIC, SEDPHAT and GUSSI. The recently developed low-noise thermogram integration approach and global analysis allow for more precise parameter estimates and more reliable quantification of multisite and multicomponent cooperative and competitive interactions. Titration experiments typically take 1-2.5 h each, and global analysis usually takes 10-20 min.

  9. Parallel macromolecular delivery and biochemical/electrochemical interface to cells employing nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    McKnight, Timothy E; Melechko, Anatoli V; Griffin, Guy D; Guillorn, Michael A; Merkulov, Vladimir L; Simpson, Michael L

    2015-03-31

    Systems and methods are described for parallel macromolecular delivery and biochemical/electrochemical interface to whole cells employing carbon nanostructures including nanofibers and nanotubes. A method includes providing a first material on at least a first portion of a first surface of a first tip of a first elongated carbon nanostructure; providing a second material on at least a second portion of a second surface of a second tip of a second elongated carbon nanostructure, the second elongated carbon nanostructure coupled to, and substantially parallel to, the first elongated carbon nanostructure; and penetrating a boundary of a biological sample with at least one member selected from the group consisting of the first tip and the second tip.

  10. Functionalization of Planet-Satellite Nanostructures Revealed by Nanoscopic Localization of Distinct Macromolecular Species

    KAUST Repository

    Rossner, Christian

    2016-09-26

    The development of a straightforward method is reported to form hybrid polymer/gold planet-satellite nanostructures (PlSNs) with functional polymer. Polyacrylate type polymer with benzyl chloride in its backbone as a macromolecular tracer is synthesized to study its localization within PlSNs by analyzing the elemental distribution of chlorine. The functionalized nanohybrid structures are analyzed by scanning transmission electron microscopy, electron energy loss spectroscopy, and spectrum imaging. The results show that the RAFT (reversible addition-fragmentation chain transfer) polymers\\' sulfur containing end groups are colocalized at the gold cores, both within nanohybrids of simple core-shell morphology and within higher order PlSNs, providing microscopic evidence for the affinity of the RAFT group toward gold surfaces. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA., Weinheim.

  11. Phase transitions of macromolecular microsphere composite hydrogels based on the stochastic Cahn–Hilliard equation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiao, E-mail: lixiao1228@163.com; Ji, Guanghua, E-mail: ghji@bnu.edu.cn; Zhang, Hui, E-mail: hzhang@bnu.edu.cn

    2015-02-15

    We use the stochastic Cahn–Hilliard equation to simulate the phase transitions of the macromolecular microsphere composite (MMC) hydrogels under a random disturbance. Based on the Flory–Huggins lattice model and the Boltzmann entropy theorem, we develop a reticular free energy suit for the network structure of MMC hydrogels. Taking the random factor into account, with the time-dependent Ginzburg-Landau (TDGL) mesoscopic simulation method, we set up a stochastic Cahn–Hilliard equation, designated herein as the MMC-TDGL equation. The stochastic term in the equation is constructed appropriately to satisfy the fluctuation-dissipation theorem and is discretized on a spatial grid for the simulation. A semi-implicit difference scheme is adopted to numerically solve the MMC-TDGL equation. Some numerical experiments are performed with different parameters. The results are consistent with the physical phenomenon, which verifies the good simulation of the stochastic term.

  12. Monetizing Leakage Risk of Geologic CO2 Storage using Wellbore Permeability Frequency Distributions

    Science.gov (United States)

    Bielicki, Jeffrey; Fitts, Jeffrey; Peters, Catherine; Wilson, Elizabeth

    2013-04-01

    Carbon dioxide (CO2) may be captured from large point sources (e.g., coal-fired power plants, oil refineries, cement manufacturers) and injected into deep sedimentary basins for storage, or sequestration, from the atmosphere. This technology—CO2 Capture and Storage (CCS)—may be a significant component of the portfolio of technologies deployed to mitigate climate change. But injected CO2, or the brine it displaces, may leak from the storage reservoir through a variety of natural and manmade pathways, including existing wells and wellbores. Such leakage will incur costs to a variety of stakeholders, which may affect the desirability of potential CO2 injection locations as well as the feasibility of the CCS approach writ large. Consequently, analyzing and monetizing leakage risk is necessary to develop CCS as a viable technological option to mitigate climate change. Risk is the product of the probability of an outcome and the impact of that outcome. Assessment of leakage risk from geologic CO2 storage reservoirs requires an analysis of the probabilities and magnitudes of leakage, identification of the outcomes that may result from leakage, and an assessment of the expected economic costs of those outcomes. One critical uncertainty regarding the rate and magnitude of leakage is determined by the leakiness of the well leakage pathway. This leakiness is characterized by a leakage permeability for the pathway, and recent work has sought to determine frequency distributions for the leakage permeabilities of wells and wellbores. We conduct a probabilistic analysis of leakage and monetized leakage risk for CO2 injection locations in the Michigan Sedimentary Basin (USA) using empirically derived frequency distributions for wellbore leakage permeabilities. To conduct this probabilistic risk analysis, we apply the RISCS (Risk Interference of Subsurface CO2 Storage) model (Bielicki et al, 2013a, 2012b) to injection into the Mt. Simon Sandstone. RISCS monetizes leakage risk

  13. PURY: a database of geometric restraints of hetero compounds for refinement in complexes with macromolecular structures.

    Science.gov (United States)

    Andrejasic, Miha; Praaenikar, Jure; Turk, Dusan

    2008-11-01

    The number and variety of macromolecular structures in complex with ;hetero' ligands is growing. The need for rapid delivery of correct geometric parameters for their refinement, which is often crucial for understanding the biological relevance of the structure, is growing correspondingly. The current standard for describing protein structures is the Engh-Huber parameter set. It is an expert data set resulting from selection and analysis of the crystal structures gathered in the Cambridge Structural Database (CSD). Clearly, such a manual approach cannot be applied to the vast and ever-growing number of chemical compounds. Therefore, a database, named PURY, of geometric parameters of chemical compounds has been developed, together with a server that accesses it. PURY is a compilation of the whole CSD. It contains lists of atom classes and bonds connecting them, as well as angle, chirality, planarity and conformation parameters. The current compilation is based on CSD 5.28 and contains 1978 atom classes and 32,702 bonding, 237,068 angle, 201,860 dihedral and 64,193 improper geometric restraints. Analysis has confirmed that the restraints from the PURY database are suitable for use in macromolecular crystal structure refinement and should be of value to the crystallographic community. The database can be accessed through the web server http://pury.ijs.si/, which creates topology and parameter files from deposited coordinates in suitable forms for the refinement programs MAIN, CNS and REFMAC. In the near future, the server will move to the CSD website http://pury.ccdc.cam.ac.uk/.

  14. Macromolecular Stabilization by Excluded Cosolutes: Mean Field Theory of Crowded Solutions.

    Science.gov (United States)

    Sapir, Liel; Harries, Daniel

    2015-07-14

    We propose a mean field theory to account for the experimentally determined temperature dependence of protein stabilization that emerges in solutions crowded by preferentially excluded cosolutes. Based on regular solution theory and employing the Flory-Huggins approximation, our model describes cosolutes in terms of their size, and two temperature-dependent microscopic parameters that correspond to macromolecule-cosolute and bulk solution interactions. The theory not only predicts a "depletion force" that can account for the experimentally observed stabilization of protein folding or association in the presence of excluded cosolutes but also predicts the full range of associated entropic and enthalpic components. Remarkably, depending on cosolute identity and in accordance with experiments, the theory describes entropically as well as enthalpically dominated depletion forces, even those disfavored by entropy. This emerging depletion attraction cannot be simply linked to molecular volumes. Instead, the relevant parameter is an effective volume that represents an interplay between solvent, cosolute, and macromolecular interactions. We demonstrate that the apparent depletion free energy is often accompanied by significant yet compensating entropy and enthalpy terms that, although having a net zero contribution to stabilization, can obscure the underlying molecular mechanism. This study underscores the importance of including often-neglected free energy terms that correspond to solvent-cosolute and cosolute-macromolecule interactions, which for most typical cosolutes are expected to be temperature dependent. We propose that experiments specifically aimed at resolving the temperature-dependence of cosolute exclusion from macromolecular surfaces should help reveal the full range of the underlying molecular mechanisms of the depletion force.

  15. PURY: a database of geometric restraints of hetero compounds for refinement in complexes with macromolecular structures.

    Science.gov (United States)

    Andrejasic, Miha; Praaenikar, Jure; Turk, Dusan

    2008-11-01

    The number and variety of macromolecular structures in complex with ;hetero' ligands is growing. The need for rapid delivery of correct geometric parameters for their refinement, which is often crucial for understanding the biological relevance of the structure, is growing correspondingly. The current standard for describing protein structures is the Engh-Huber parameter set. It is an expert data set resulting from selection and analysis of the crystal structures gathered in the Cambridge Structural Database (CSD). Clearly, such a manual approach cannot be applied to the vast and ever-growing number of chemical compounds. Therefore, a database, named PURY, of geometric parameters of chemical compounds has been developed, together with a server that accesses it. PURY is a compilation of the whole CSD. It contains lists of atom classes and bonds connecting them, as well as angle, chirality, planarity and conformation parameters. The current compilation is based on CSD 5.28 and contains 1978 atom classes and 32,702 bonding, 237,068 angle, 201,860 dihedral and 64,193 improper geometric restraints. Analysis has confirmed that the restraints from the PURY database are suitable for use in macromolecular crystal structure refinement and should be of value to the crystallographic community. The database can be accessed through the web server http://pury.ijs.si/, which creates topology and parameter files from deposited coordinates in suitable forms for the refinement programs MAIN, CNS and REFMAC. In the near future, the server will move to the CSD website http://pury.ccdc.cam.ac.uk/. PMID:19020347

  16. Simulations of hydraulic fracturing and leakage in sedimentary basins

    Energy Technology Data Exchange (ETDEWEB)

    Lothe, Ane Elisabeth

    2004-01-01

    Hydraulic fracturing and leakage of water through the caprock is described from sedimentary basin over geological time scale. Abnormal pressure accumulations reduce the effective stresses in the underground and trigger the initiation of hydraulic fractures. The major faults in the basin define these pressure compartments. In this Thesis, basin simulations of hydraulic fracturing and leakage have been carried out. A simulator (Pressim) is used to calculate pressure generation and dissipitation between the compartments. The flux between the compartments and not the flow within the compartments is modelled. The Griffith-Coulomb failure criterion determines initial failure at the top structures of overpressured compartments, whereas the frictional sliding criterion is used for reactivation along the same fractures. The minimum horizontal stress is determined from different formulas, and an empirical one seems to give good results compared to measured pressures and minimum horizontal stresses. Simulations have been carried out on two datasets; one covering the Halten Terrace area and one the Tune Field area in the northern North Sea. The timing of hydraulic fracturing and amount of leakage has been quantified in the studies from the Halten Terrace area. This is mainly controlled by the lateral fluid flow and the permeability of the major faults in the basin. Low fault permeability gives early failure, while high fault permeabilities results in no or late hydraulic fracturing and leakage from overpressured parts of the basin. In addition to varying the transmissibility of all faults in a basin, the transmissibility across individual faults can be varied. Increasing the transmissibility across faults is of major importance in overpressured to intermediately pressured areas. However, to obtain change in the flow, a certain pressure difference has to be the situation between the different compartments. The coefficient of internal friction and the coefficient of frictional

  17. Power Beaming Leakage Radiation as a SETI Observable

    Science.gov (United States)

    Benford, James N.; Benford, Dominic J.

    2016-07-01

    The most observable leakage radiation from an advanced civilization may well be from the use of power beaming to transfer energy and accelerate spacecraft. Applications suggested for power beaming involve launching spacecraft to orbit, raising satellites to a higher orbit, and interplanetary concepts involving space-to-space transfers of cargo or passengers. We also quantify beam-driven launch to the outer solar system, interstellar precursors, and ultimately starships. We estimate the principal observable parameters of power beaming leakage. Extraterrestrial civilizations would know their power beams could be observed, and so could put a message on the power beam and broadcast it for our receipt at little additional energy or cost. By observing leakage from power beams we may find a message embedded on the beam. Recent observations of the anomalous star KIC 8462852 by the Allen Telescope Array (ATA) set some limits on extraterrestrial power beaming in that system. We show that most power beaming applications commensurate with those suggested for our solar system would be detectable if using the frequency range monitored by the ATA, and so the lack of detection is a meaningful, if modest, constraint on extraterrestrial power beaming in that system. Until more extensive observations are made, the limited observation time and frequency coverage are not sufficiently broad in frequency and duration to produce firm conclusions. Such beams would be visible over large interstellar distances. This implies a new approach to the SETI search: instead of focusing on narrowband beacon transmissions generated by another civilization, look for more powerful beams with much wider bandwidth. This requires a new approach for their discovery by telescopes on Earth. Further studies of power beaming applications should be performed, potentially broadening the parameter space of the observable features that we have discussed here.

  18. The impact of daily covers on sidewall leakage in landfills

    Energy Technology Data Exchange (ETDEWEB)

    Welker, A. L. [Villanova Univ., Dept. of Civil Engineering, PA (United States)

    2000-09-01

    Typically, sanitary landfills are covered by 15 cm of locally available soil on a daily basis. This practice is intended to limit short term negative effects of the waste material on the above-ground environment such as odor, fire, or vermin attraction. Daily placement of compacted soil creates low hydraulic conductivity stratifying layers within the landfill which, in due course, may result in side-slope seepage, decreased stability and decreased efficiency of methane gas venting. The expense of soil acquisitions and the the diminishing availability of landfill space increases the need for alternative materials to replace the daily cover. This paper examines the the threat of sidewall landfill leakage for a hypothetical landfill with traditional soil cover and an alternative daily cover, to demonstrate that the threat of sidewall leakage is real and can be decreased with the use of alternative material as the daily cover such as crushed glass, sludge from waste-water treatment plants, industrial waste, foams and various geosynthetics. At the same time, results of the modelling study showed that with proper drainage sidewall seepage will not occur even with a daily cover that has a hydraulic conductivity two orders of magnitude smaller than the waste, despite positive pressure building up on top of the daily cover. These results imply that the threat of sidewall leakage is minimal, and while alternative daily cover material would help to reduce it even further, their use is most likely to be the result of economic, not technical, considerations. 12 refs., 3 tabs., 4 figs.

  19. Impeller leakage flow modeling for mechanical vibration control

    Science.gov (United States)

    Palazzolo, Alan B.

    1996-01-01

    HPOTP and HPFTP vibration test results have exhibited transient and steady characteristics which may be due to impeller leakage path (ILP) related forces. For example, an axial shift in the rotor could suddenly change the ILP clearances and lengths yielding dynamic coefficient and subsequent vibration changes. ILP models are more complicated than conventional-single component-annular seal models due to their radial flow component (coriolis and centrifugal acceleration), complex geometry (axial/radial clearance coupling), internal boundary (transition) flow conditions between mechanical components along the ILP and longer length, requiring moment as well as force coefficients. Flow coupling between mechanical components results from mass and energy conservation applied at their interfaces. Typical components along the ILP include an inlet seal, curved shroud, and an exit seal, which may be a stepped labyrinth type. Von Pragenau (MSFC) has modeled labyrinth seals as a series of plain annular seals for leakage and dynamic coefficient prediction. These multi-tooth components increase the total number of 'flow coupled' components in the ILP. Childs developed an analysis for an ILP consisting of a single, constant clearance shroud with an exit seal represented by a lumped flow-loss coefficient. This same geometry was later extended to include compressible flow. The objective of the current work is to: supply ILP leakage-force impedance-dynamic coefficient modeling software to MSFC engineers, base on incompressible/compressible bulk flow theory; design the software to model a generic geometry ILP described by a series of components lying along an arbitrarily directed path; validate the software by comparison to available test data, CFD and bulk models; and develop a hybrid CFD-bulk flow model of an ILP to improve modeling accuracy within practical run time constraints.

  20. Air Leakage and Air Transfer Between Garage and Living Space

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, A.

    2014-09-01

    This research project focused on evaluation of air transfer between the garage and living space in a single-family detached home constructed by a production homebuilder in compliance with the 2009 International Residential Code and the 2009 International Energy Conservation Code. The project gathered important information about the performance of whole-building ventilation systems and garage ventilation systems as they relate to minimizing flow of contaminated air from garage to living space. A series of 25 multi-point fan pressurization tests and additional zone pressure diagnostic testing characterized the garage and house air leakage, the garage-to-house air leakage, and garage and house pressure relationships to each other and to outdoors using automated fan pressurization and pressure monitoring techniques. While the relative characteristics of this house may not represent the entire population of new construction configurations and air tightness levels (house and garage) throughout the country, the technical approach was conservative and should reasonably extend the usefulness of the results to a large spectrum of house configurations from this set of parametric tests in this one house. Based on the results of this testing, the two-step garage-to-house air leakage test protocol described above is recommended where whole-house exhaust ventilation is employed. For houses employing whole-house supply ventilation (positive pressure) or balanced ventilation (same pressure effect as the Baseline condition), adherence to the EPA Indoor airPLUS house-to-garage air sealing requirements should be sufficient to expect little to no garage-to-house air transfer.

  1. Early localization of containment leakage during an accident

    International Nuclear Information System (INIS)

    In case of an accident in a nuclear plant, checking the containment leaktightness would be a fundamental step for the diagnosis and prognosis of the radiological consequences. Significant help in this task can be provided by softwares. For that purpose, the French Atomic Energy Commission (CEA) is developing an expert system which can provide early in the accident a classification of the possible leakage paths and help understanding the necessary corrections which have to be undertaken by the utility. This software will be used at the Emergency Technical Center of the CEA. Its basic principles are described in this paper

  2. Numerical Simulations of Leakage from Underground LPG Storage Caverns

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Hajime; Pruess, Karsten

    2004-09-01

    To secure a stable supply of petroleum gas, underground storage caverns for liquified petroleum gas (LPG) are commonly used in many countries worldwide. Storing LPG in underground caverns requires that the surrounding rock mass remain saturated with groundwater and that the water pressure be higher than the liquid pressure inside the cavern. In previous studies, gas containment criteria for underground gas storage based on hydraulic gradient and pressure have been discussed, but these studies do not consider the physicochemical characteristics and behavior of LPG such as vaporization and dissolution in groundwater. Therefore, while these studies are very useful for designing storage caverns, they do not provide better understanding of the either the environmental effects of gas contamination or the behavior of vaporized LPG. In this study, we have performed three-phase fluid flow simulations of gas leakage from underground LPG storage caverns, using the multiphase multicomponent nonisothermal simulator TMVOC (Pruess and Battistelli, 2002), which is capable of solving the three-phase nonisothermal flow of water, gas, and a multicomponent mixture of volatile organic chemicals (VOCs) in multidimensional heterogeneous porous media. A two-dimensional cross-sectional model resembling an actual underground LPG facility in Japan was developed, and gas leakage phenomena were simulated for three different permeability models: (1) a homogeneous model, (2) a single-fault model, and (3) a heterogeneous model. In addition, the behavior of stored LPG was studied for the special case of a water curtain suddenly losing its function because of operational problems, or because of long-term effects such as clogging of boreholes. The results of the study indicate the following: (1) The water curtain system is a very powerful means for preventing gas leakage from underground storage facilities. By operating with appropriate pressure and layout, gas containment can be ensured. (2

  3. A study of tip-leakage flow through orifice investigations

    OpenAIRE

    Henry, Gregory S.

    1987-01-01

    Compressible fluid dynamics of flow through plain-faced long orifices was investigated with the hope of gaining insight into the fluid dynamics of tip leakage flow. The Reynolds number range investigated was greater than 10*. Measurements were made of the discharge coefficient as a function of back pressure ratio for a sharp-edged orifice and long orifices with an l/d from 1/2 to 8. The discharge coefficient measurements indicate the mass flow rate in an orifice with an l/d of ...

  4. Magnetic mechanisms of magnetic flux leakage nondestructive testing

    Science.gov (United States)

    Sun, Yanhua; Kang, Yihua

    2013-10-01

    The widely applied magnetic flux leakage (MFL) nondestructive testing for ferrous materials has been simply explained by "MFL escaping from defects and being induced is exactly the MFL testing principle," with a rough application for evaluation. Hence, we analyze the "escape" course of MFL generation using magnetic refraction and explain the reason why the MFL technology really exists in practice. Furthermore, we also point out that the presently so-called MFL testing technique essentially hides a different signal component arising from bump-shaped defects features unlike the MFL caused by concave-shaped ones, explained by another forming mechanism.

  5. An Improved Method for Preventing Data Leakage in an Organization

    Directory of Open Access Journals (Sweden)

    Neetu Bose

    2016-04-01

    Full Text Available Data is one of the most important assets an organisation has since it denes each organisations unique- ness.It includes data on members and prospects, their inter- ests and purchases, your events, speakers, your content, social media, press, your staff, budget, strategic plan, and much more. As organizations open their doors to employees, part- ners, customers and suppliers to provide deeper access to sensitive information, the risk sassociated with business increase. Now, more than ever, within creasing threats of cyber terrorism, cor- porate governance issues, fraud, and identity theft, the need for securing corporate information has become paramount. Informa- tion theft is not just about external hackers and unauthorized external users stealing your data, it is also about managing internal employees and even contractors who may be working within your organization for short periods of time. Adding to the challenge of securing information is the increasing push for corporate governance and adherence to legislative or regulatory requirements. Failure to comply and provide privacy, audit and internal controls could result in penalties ranging from large nes to jail terms. Non-compliance can result in not only potential implications for executives, but also possible threats to the viability of a corporation. Insiders too represent a sign cant risk to data security. The task of detecting malicious insiders is very challenging as the methods of deception become more and more sophisticated. There are various solutions present to avoid data leakage. Data leakage detection, prevention (DLPM and monitoring solutions became an inherent component of the organizations security suite.DLP solutions monitors sensitive data when at rest, in motion, or in use and enforce the organizational data protection policy.These solutions focus mainly on the data and its sensitivity level, and on preventing it from reaching an unauthorized person. They ignore the fact

  6. Leakage investigation at Shalamar Garden, Lahore using radioisotopes

    International Nuclear Information System (INIS)

    A sealed caesium-137 radiation source and 73 injections of sodium-24 in water soluble form have been successfully employed to detect leakage points and determine the layout pattern of a terracotta pipeline grid feeding the decorative fountains of the central tank in the middle terrace of Shalamar Garden, Lahore. The pipeline system is about 350 years old and no drawing or layout plan was available before the studies. The present investigation is an effort to help restore the original historic water supply system. (author)

  7. Contrast media for radiological examination in gastrointestinal tract leakage

    International Nuclear Information System (INIS)

    The aim of this investigation has been to find a safe and suitable contrast medium (CM) for radiological evaluation of the gastrointestinal tract (GIT) in cases where leakage outside the GIT can be suspected. An experimental study was carried out to evaluate the reactions of various available CM in the bronchi and lungs, mediastinum, pleura and peritoneum of rats. The CM evaluated in the experimental study were, pure barium sulphate (without any additives), commercial barium sulphate (Micropaque, with additives), Dionosil, Hytrast, Gastrografin, Amipaque (in pleura Omnipaque) and Hexabrix. (Auth.)

  8. A nationwide study on anastomotic leakage after colonic cancer surgery

    DEFF Research Database (Denmark)

    Krarup, Peter-Martin; Jorgensen, L N; Andreasen, A H;

    2012-01-01

    Aim: Anastomotic leakage (AL) is a major challenge in colorectal cancer surgery due to increased morbidity and mortality. Possible risk factors should be investigated differentially, distinguishing between rectal and colonic surgery in large-scale studies to avoid selection bias and confounding.......01-1.07; P = 0.03); blood transfusion (OR, 10.27; 95% CI, 6.82-15.45); P <0.001) and female gender (OR, 0.71; 95% CI, 0.57-0.89; P = 0.02) were associated with AL in the multivariate analysis. Conclusion: The main finding that a laparoscopic approach was associated with increased risk of AL should prompt...

  9. Application Of The Climafor Baseline To Determine Leakage: TheCase Of Scolel Te.

    Energy Technology Data Exchange (ETDEWEB)

    De Jong, B.H.J.; Bazan, E. Esquivel; Quechulpa Montalvo, S.

    2007-06-01

    The acceptance of forestry-based project activities tomitigate greenhouse gases emissions has been subjected to a number ofmethodological questions to be answered, of which the most challengingare baseline establishment and identification of and measuring leakage.Here we pose hypotheses for and quantify leakage of the Scolel Te projectin Chiapas, Mexico. In this project small-scale farmers are implementingforestry, agroforestry, and forest conservation activities, with carbonsequestration as one of the goals. The main leakage monitoring domain isdefined as the area owned by the participating farmers or communitiesoutside the area where the specific project activities take place. Thenull-hypothesis (no leakage) is that non-project land owned by the farmeror community will experience the same carbon stock changes as predictedby the regional baseline, specifically developed for the project. Firstwe assessed the most likely causes and sources of leakage that may occurin the project. From this analysis, one type of leakage seems to beimportant, i.e., activity shifting. Second we estimated the leakage of asample of participating farmers and communities. Actual land use was thencompared with expected land use derived from the baseline. The Plan Vivoof each participant, complemented with readily available tools toidentify the main sources and drivers of leakage are used to developsimple leakage assessment procedures, as demonstrated in this paper.Negative leakage was estimated to be negligible in this study.Incorporating these procedures already in the project planning stage willreduce the uncertainties related to the actual carbon mitigationpotential of any forestry project.

  10. Studies of axial-leakage simulations for homogeneous and heterogeneous EBR-II core configurations

    Energy Technology Data Exchange (ETDEWEB)

    Grimm, K.N.; Meneghetti, D.

    1985-08-01

    When calculations of flux are done in less than three dimensions, leakage-absorption cross sections are normally used to model leakages (flows) in the dimensions for which the flux is not calculated. Since the neutron flux is axially dependent, the leakages, and hence the leakage-absorption cross sections, are also axially dependent. Therefore, to obtain axial flux profiles (or reaction rates) for individual subassemblies, an XY-geometry calculation delineating each subassembly has to be done at several axial heights with space- and energy-dependent leakage-absorption cross sections that are appropriate for each height. This report discusses homogeneous and heterogeneous XY-geometry calculations at various axial locations and using several differing assumptions for the calculation of the leakage-absorption cross section. The positive (outward) leakage-absorption cross sections are modeled as actual leakage absorptions, but the negative (inward) leakage-absorption cross sections are modeled as either negative leakage absorptions (+-B/sup 2/ method) or positive downscatter cross sections (the ..sigma../sub s/(1 ..-->.. g) method). 3 refs., 52 figs., 10 tabs.

  11. Secure Mobile Agent from Leakage-Resilient Proxy Signatures

    Directory of Open Access Journals (Sweden)

    Fei Tang

    2015-01-01

    Full Text Available A mobile agent can sign a message in a remote server on behalf of a customer without exposing its secret key; it can be used not only to search for special products or services, but also to make a contract with a remote server. Hence a mobile agent system can be used for electronic commerce as an important key technology. In order to realize such a system, Lee et al. showed that a secure mobile agent can be constructed using proxy signatures. Intuitively, a proxy signature permits an entity (delegator to delegate its signing right to another entity (proxy to sign some specified messages on behalf of the delegator. However, the proxy signatures are often used in scenarios where the signing is done in an insecure environment, for example, the remote server of a mobile agent system. In such setting, an adversary could launch side-channel attacks to exploit some leakage information about the proxy key or even other secret states. The proxy signatures which are secure in the traditional security models obviously cannot provide such security. Based on this consideration, in this paper, we design a leakage-resilient proxy signature scheme for the secure mobile agent systems.

  12. An Advanced Leakage Scheme for Neutrino Treatment in Astrophysical Simulations

    Science.gov (United States)

    Perego, A.; Cabezón, R. M.; Käppeli, R.

    2016-04-01

    We present an Advanced Spectral Leakage (ASL) scheme to model neutrinos in the context of core-collapse supernovae (CCSNe) and compact binary mergers. Based on previous gray leakage schemes, the ASL scheme computes the neutrino cooling rates by interpolating local production and diffusion rates (relevant in optically thin and thick regimes, respectively) separately for discretized values of the neutrino energy. Neutrino trapped components are also modeled, based on equilibrium and timescale arguments. The better accuracy achieved by the spectral treatment allows a more reliable computation of neutrino heating rates in optically thin conditions. The scheme has been calibrated and tested against Boltzmann transport in the context of Newtonian spherically symmetric models of CCSNe. ASL shows a very good qualitative and a partial quantitative agreement for key quantities from collapse to a few hundreds of milliseconds after core bounce. We have proved the adaptability and flexibility of our ASL scheme, coupling it to an axisymmetric Eulerian and to a three-dimensional smoothed particle hydrodynamics code to simulate core collapse. Therefore, the neutrino treatment presented here is ideal for large parameter-space explorations, parametric studies, high-resolution tests, code developments, and long-term modeling of asymmetric configurations, where more detailed neutrino treatments are not available or are currently computationally too expensive.

  13. AN ADVANCED LEAKAGE SCHEME FOR NEUTRINO TREATMENT IN ASTROPHYSICAL SIMULATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Perego, A. [Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstraße 2, D-64289 Darmstadt (Germany); Cabezón, R. M. [Physics Department, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Käppeli, R., E-mail: albino.perego@physik.tu-darmstadt.de [Seminar for Applied Mathematics, ETH Zürich, Rämistrasse 101, 8092 Zürich (Switzerland)

    2016-04-15

    We present an Advanced Spectral Leakage (ASL) scheme to model neutrinos in the context of core-collapse supernovae (CCSNe) and compact binary mergers. Based on previous gray leakage schemes, the ASL scheme computes the neutrino cooling rates by interpolating local production and diffusion rates (relevant in optically thin and thick regimes, respectively) separately for discretized values of the neutrino energy. Neutrino trapped components are also modeled, based on equilibrium and timescale arguments. The better accuracy achieved by the spectral treatment allows a more reliable computation of neutrino heating rates in optically thin conditions. The scheme has been calibrated and tested against Boltzmann transport in the context of Newtonian spherically symmetric models of CCSNe. ASL shows a very good qualitative and a partial quantitative agreement for key quantities from collapse to a few hundreds of milliseconds after core bounce. We have proved the adaptability and flexibility of our ASL scheme, coupling it to an axisymmetric Eulerian and to a three-dimensional smoothed particle hydrodynamics code to simulate core collapse. Therefore, the neutrino treatment presented here is ideal for large parameter-space explorations, parametric studies, high-resolution tests, code developments, and long-term modeling of asymmetric configurations, where more detailed neutrino treatments are not available or are currently computationally too expensive.

  14. Low standby leakage 12T SRAM cell characterisation

    Science.gov (United States)

    Yadav, Arjun; Nakhate, Sangeeta

    2016-09-01

    In this work, a low power and variability-aware static random access memory (SRAM) architecture based on a twelve-transistor (12T) cell is proposed. This cell obtains low static power dissipation due to a parallel global latch (G-latch) and storage latch (S-latch), along with a global wordline (GWL), which offer a high cell ratio and pull-up ratio for reliable read and write operations and a low cell ratio and pull-up ratio during idle mode to reduce the standby power dissipation. In the idle state, only the S-latch stores bits, while the G-latch is isolated from the S-latch and the GWL is deactivated. The leakage power consumption of the proposed SRAM cell is thereby reduced by 38.7% compared to that of the conventional six-transistor (6T) SRAM cell. This paper evaluates the impact of the chip supply voltage and surrounding temperature variations on the standby leakage power and observes considerable improvement in the power dissipation. The read/write access delay, read static noise margin (SNM) and write SNM were evaluated, and the results were compared with those of the standard 6T SRAM cell. The proposed cell, when compared with the existing cell using the Monte Carlo method, shows an appreciable improvement in the standby power dissipation and layout area.

  15. Detection and quantification of methane leakage from landfills

    Energy Technology Data Exchange (ETDEWEB)

    Ljungberg, Sven-Aake; Maartensson, Stig-Goeran (Univ. of Gaevle, Gaevle (Sweden)); Meijer, Jan-Erik; Rosqvist, Haakan (NSR AB, Helsingborg (Sweden))

    2009-03-15

    The purpose of this project was to detect gas leakage and to measure and quantify methane emission from landfills using modern remote sensing techniques. In this project, a handheld laser instrument and an IR camera were used. The overall objective was to develop cost-effective methods for detecting and quantifying methane emissions from landfills. There are many methods available for measuring the methane concentration in air, both from close-up and from long distances. Combined with the use of a tracer gas, the methane emission from entire landfills can be measured relatively accurately. A number of methods are used to detect leakage from parts of landfill surfaces, but there are few methods for quantifying leakage from sub-zones. Field measurements with the laser instrument and the IR camera were carried out at seven Swedish landfills and two landfills in France. The investigated surfaces at the Swedish landfills were divided into different zones, such as top surface, slope, crest and toe of slope. The field measurements in France were taken over entire landfills. The methane emission varied between the different landfills in the project, and also between the different landfill zones. The results from repeated field measurements indicated that a landfill with a final cap and a successful gas recovery system produces barely measurable emissions. The weak points at a landfill are generally slopes, including crests and toes of slopes. Where the covering of the waste is inadequate, leakage often occurs at lift joints and in areas where waste protrudes through the cover. Other weak points are deficiencies in the gas recovery system. Leachate systems can lead landfill gas and thereby cause methane leakage. Along with wind velocity and variations in atmospheric pressure, moisture content in the ground is an important factor that affects methane emissions from landfill surfaces. Results from field measurements of the same feature/surface at different points in time and

  16. Angiopoietin-2 is critical for cytokine-induced vascular leakage.

    Science.gov (United States)

    Benest, Andrew V; Kruse, Karoline; Savant, Soniya; Thomas, Markus; Laib, Anna M; Loos, Elias K; Fiedler, Ulrike; Augustin, Hellmut G

    2013-01-01

    Genetic experiments (loss-of-function and gain-of-function) have established the role of Angiopoietin/Tie ligand/receptor tyrosine kinase system as a regulator of vessel maturation and quiescence. Angiopoietin-2 (Ang-2) acts on Tie2-expressing resting endothelial cells as an antagonistic ligand to negatively interfere with the vessel stabilizing effects of constitutive Ang-1/Tie-2 signaling. Ang-2 thereby controls the vascular response to inflammation-inducing as well as angiogenesis-inducing cytokines. This study was aimed at assessing the role of Ang-2 as an autocrine (i.e. endothelial-derived) regulator of rapid vascular responses (within minutes) caused by permeability-inducing agents. Employing two independent in vivo assays to quantitatively assess vascular leakage (tracheal microsphere assay, 1-5 min and Miles assay, 20 min), the immediate vascular response to histamine, bradykinin and VEGF was analyzed in Ang-2-deficient (Ang-2(-/-)) mice. In comparison to the wild type control mice, the Ang2(-/-) mice demonstrated a significantly attenuated response. The Ang-2(-/-) phenotype was rescued by systemic administration (paracrine) of an adenovirus encoding Ang-2. Furthermore, cytokine-induced intracellular calcium influx was impaired in Ang-2(-/-) endothelioma cells, consistent with reduced phospholipase activation in vivo. Additionally, recombinant human Ang-2 (rhAng-2) alone was unable to induce vascular leakage. In summary, we report here in a definite genetic setting that Ang-2 is critical for multiple vascular permeability-inducing cytokines. PMID:23940579

  17. Assessment of leakage from an engineered reservoir using hydrogeological tools

    Energy Technology Data Exchange (ETDEWEB)

    Smerdon, B.D.; Mendoza, C.A. [Alberta Univ., Edmonton, AB (Canada); McCann, A.; Kraushar, C. [Omni-McCann Consultants Ltd., Edmonton, AB (Canada); Nilson, A. [Alberta Infrastructure, Edmonton, AB (Canada)

    2003-07-01

    Seepage from earth-filled dams can be determined using steady-state, cross sectional, flow net analysis or transient response to fluid pressure within dam construction materials. This paper described the methods used to quantify leakage from a surface-water reservoir (Pine Coulee) located in southern Alberta. The methods included buried valley aquifer tests, three-dimensional groundwater flow simulations and stable isotope water samples. The aquifer tests were conducted when the reservoir was maintained at leaking elevation as well as when it was at non-leaking elevation. When the reservoir was leaking, the results showed a recharge boundary condition in the aquifer. When the reservoir was not leaking, a barrier boundary was present. To verify field-measured parameters and to determine the hydraulic properties and location of the leakage zone, three-dimensional groundwater flow simulations were calibrated to the datasets. Stable isotopes confirmed the seepage of reservoir water to the aquifer. Seepage rates and the required aquifer pumping rates to control aquifer water levels were predicted by the model. The results were in good agreement with field observations since relief well installation. The use of hydrogeological tools proved to be diagnostic and predictive in assessing the subsurface dynamics associated with man-made reservoirs. 15 refs., 2 tabs., 6 figs.

  18. Greater focus needed on methane leakage from natural gas infrastructure.

    Science.gov (United States)

    Alvarez, Ramón A; Pacala, Stephen W; Winebrake, James J; Chameides, William L; Hamburg, Steven P

    2012-04-24

    Natural gas is seen by many as the future of American energy: a fuel that can provide energy independence and reduce greenhouse gas emissions in the process. However, there has also been confusion about the climate implications of increased use of natural gas for electric power and transportation. We propose and illustrate the use of technology warming potentials as a robust and transparent way to compare the cumulative radiative forcing created by alternative technologies fueled by natural gas and oil or coal by using the best available estimates of greenhouse gas emissions from each fuel cycle (i.e., production, transportation and use). We find that a shift to compressed natural gas vehicles from gasoline or diesel vehicles leads to greater radiative forcing of the climate for 80 or 280 yr, respectively, before beginning to produce benefits. Compressed natural gas vehicles could produce climate benefits on all time frames if the well-to-wheels CH(4) leakage were capped at a level 45-70% below current estimates. By contrast, using natural gas instead of coal for electric power plants can reduce radiative forcing immediately, and reducing CH(4) losses from the production and transportation of natural gas would produce even greater benefits. There is a need for the natural gas industry and science community to help obtain better emissions data and for increased efforts to reduce methane leakage in order to minimize the climate footprint of natural gas. PMID:22493226

  19. Helium/solid powder O-ring leakage correlation experiments

    International Nuclear Information System (INIS)

    We have developed a method to test powder leakage that has passed O-ring seals. To validate this method we have spiked a test fixture with 98 ng of U and recovered 130 +- 25 ng of U. We did not detect U at a detection limit of 26 ng in a fixture which was treated as a blank. This method has been applied to the leakage of UO2 powder passing the type of EPDM O-ring seals used in a SNM shipping cask belonging to PNC. Considering the three experimental tests in which no or very small quantities of U were detected as effective blank test, it appears that the level of external contamination is negligible. Therefore, we believe that the U quantities greater than 26 ng (6 tests) passed the primary O-ring seal. From this limited quantity of data, we observe no apparent correlation between the amount of U measured and either helium leak rate or equivalent tube diameter. The data for the 1300C tests indicate the possibility of a U/time relationship; however, more data are needed for verification

  20. Heparin Leakage in Central Venous Catheters by Hemodynamic Transport

    Science.gov (United States)

    Barbour, Michael; McGah, Patrick; Gow, Kenneth; Aliseda, Alberto

    2014-11-01

    Central venous catheters (CVCs), placed in the superior vena cava for hemodialysis, are routinely filled with heparin, an anticoagulant, while not in use to maintain patency and prevent thrombus formation at the catheter tip. However, the heparin-lock procedure places the patient at risk for systemic bleeding incidences, as heparin is known to leak into the blood stream. We propose that the driving mechanism behind heparin leakage is advective-diffusive transport due to the pulsatile blood flow surrounding the catheter tip. This novel hypothesis is based on Planar Laser Induced Fluorescence (PLIF) measurements of heparin transport from a CVC placed inside an in vitro pulsatile flow loop and validated with CFD simulations. The results show an initial, fast (catheter lumen, where concentration is still high, that is insufficient at replenishing the lost heparin at the tip. These results, which estimate leakage rates consistent with published in vivo data, predict that the concentration of heparin at the catheter tip is effectively zero for the majority of the interdialytic phase, rendering the heparin lock ineffective.

  1. Credibility Assessments as 'Normative Leakage': Asylum Applications, Gender and Class

    Directory of Open Access Journals (Sweden)

    Hanna Wikström

    2013-10-01

    Full Text Available Based on the assumption that credibility assessments function as 'normative leakage' within the asylum process, we analyse how narratives of gender and class are articulated, rendered meaningful, or silenced in credibility assessments. Two cases concerning male applicants are selected in order to illustrate these processes. In relation to the existing concepts of internal/external credibility, we wish to introduce the concept of social credibility, which focuses on how the assessors read different socio-cultural narratives. While previous research has shown that the postcolonial will to protect women favours women as victims of patriarchal cultures, we wish to point out the continuity of this line of argumentation in relation to male and female applicants by adopting a theoretical generalization: male applicants instead become situated at the other end of the spectrum of postcolonial notions of modernity as non-victims, victims of other circumstances or perpetrators. We argue that these processes are accentuated in relation to credibility assessments. In order to prevent processes of social exclusion and to enhance inclusive practice, authorities need to acknowledge the 'normative leakage' associated with the assessment process.

  2. The impact of added insulation on air leakage

    Energy Technology Data Exchange (ETDEWEB)

    Anon

    2002-01-01

    It is relatively easy to calculate the impact on energy consumption when thermal insulation is added to the building envelope. However, other effects such as air leakage through the exterior wall assembly, and the potential for water condensation also have to be considered. By adding insulation to the exterior wall assembly, the temperature gradient of the wall is changed and the risk of condensation is increased, especially if warm, moist indoor air can flow through the wall. The study by Dominique Derome, Paul Fazio and Guylaine Desmarais for the CMHC Research Division, of which this paper is a summary, examined three types of air leakage paths, i.e. long air exfiltration path; concentrated air exfiltration path; and distributed exfiltration path. Experiments involved placing 38 mm rigid extruded polystyrene insulation on the interior side of three wood studs and fiberglass batt insulation wall assemblies, while four other samples had the same 38 mm rigid extruded polystyrene insulation added on the exterior of the assembly over the fiberboard sheathing. Both, warm and cold side additions of rigid foam insulation to the existing assemblies increased thermal performance by 55 per cent. When blown cellulose fibre was used as insulation instead of fibreglass batting, the increase in thermal performance was 66 per cent. Addition of the rigid foam insulation on the warm side tended to increase the effectiveness. For example, moisture content generally did not rise above 25 per cent, whereas it could climb up to 70 per cent when the insulation was added on the cold side.

  3. Leakage current measurements on pixelated CdZnTe detectors

    International Nuclear Information System (INIS)

    In the field of the R and D of a new generation hard X-ray cameras for space applications we focus on the use of pixelated CdTe or CdZnTe semiconductor detectors. They are covered with 64 (0.9x0.9 mm2) or 256 (0.5x0.5 mm2) pixels, surrounded by a guard ring and operate in the energy ranging from several keV to 1 MeV, at temperatures between -20 and +20 oC. A critical parameter in the characterisation of these detectors is the leakage current per pixel under polarisation (∼50-500 V/mm). In operation mode each pixel will be read-out by an integrated spectroscopy channel of the multi-channel IDeF-X ASIC currently developed in our lab. The design and functionality of the ASIC depends directly on the direction and value of the current. A dedicated and highly insulating electronics circuit is designed to automatically measure the current in each individual pixel, which is in the order of tens of pico-amperes. Leakage current maps of different CdZnTe detectors of 2 and 6 mm thick and at various temperatures are presented and discussed. Defect density diagnostics have been performed by calculation of the activation energy of the material

  4. Angiopoietin-2 is critical for cytokine-induced vascular leakage.

    Directory of Open Access Journals (Sweden)

    Andrew V Benest

    Full Text Available Genetic experiments (loss-of-function and gain-of-function have established the role of Angiopoietin/Tie ligand/receptor tyrosine kinase system as a regulator of vessel maturation and quiescence. Angiopoietin-2 (Ang-2 acts on Tie2-expressing resting endothelial cells as an antagonistic ligand to negatively interfere with the vessel stabilizing effects of constitutive Ang-1/Tie-2 signaling. Ang-2 thereby controls the vascular response to inflammation-inducing as well as angiogenesis-inducing cytokines. This study was aimed at assessing the role of Ang-2 as an autocrine (i.e. endothelial-derived regulator of rapid vascular responses (within minutes caused by permeability-inducing agents. Employing two independent in vivo assays to quantitatively assess vascular leakage (tracheal microsphere assay, 1-5 min and Miles assay, 20 min, the immediate vascular response to histamine, bradykinin and VEGF was analyzed in Ang-2-deficient (Ang-2(-/- mice. In comparison to the wild type control mice, the Ang2(-/- mice demonstrated a significantly attenuated response. The Ang-2(-/- phenotype was rescued by systemic administration (paracrine of an adenovirus encoding Ang-2. Furthermore, cytokine-induced intracellular calcium influx was impaired in Ang-2(-/- endothelioma cells, consistent with reduced phospholipase activation in vivo. Additionally, recombinant human Ang-2 (rhAng-2 alone was unable to induce vascular leakage. In summary, we report here in a definite genetic setting that Ang-2 is critical for multiple vascular permeability-inducing cytokines.

  5. SETI via Leakage from Light Sails in Exoplanetary Systems

    CERN Document Server

    Guillochon, James

    2015-01-01

    The primary challenge of rocket propulsion is the burden of needing to accelerate the spacecraft's own fuel, resulting in only a logarithmic gain in maximum speed as propellant is added to the spacecraft. Light sails offer an attractive alternative in which fuel is not carried by the spacecraft, with acceleration being provided by an external source of light. By artificially illuminating the spacecraft with beamed radiation, speeds are only limited by the area of the sail, heat resistance of its material, and power use of the accelerating apparatus. In this paper, we show that leakage from a light sail propulsion apparatus in operation around a solar system analogue would be detectable. To demonstrate this, we model the launch and arrival of a microwave beam-driven light sail constructed for transit between planets in orbit around a single star, and find an optimal beam frequency on the order of tens of GHz. Leakage from these beams yields transients with flux densities of 0.1 Jy and durations of seconds at 1...

  6. Subthreshold Leakage Minimization in MOSFET using Sleep Transistor Circuit

    Directory of Open Access Journals (Sweden)

    Shailesh Kumar Mukati

    2014-05-01

    Full Text Available The excessive power consumption has become one in all the first hindrances to the more advances of CMOS integrated circuits. Low power circuit style is a crucial analysis space. there are 3 primary stimuli for low power circuit design: setting friendly inexperienced computing, battery life extension for mobile applications, and rising self-sufficing battery replacement free applications like intelligent sensing element nodes. The leakage current in MOSFET is due to subthreshold leakage current due to parasitic pn junctions. The sleep transistor is use between CMOS logic and supply rail. Our technique, sleep transistor square measure placed between the circuits offer and provide rails to show off the run current flow throughout idle time this will be done by victimization one PMOS transistor and one NMOS transistor nonparallel with the transistors of every logic block to make a virtual ground and a virtual power supply. constant estimation victimization town simulation will acquire a comparatively correct estimation of the run distribution; but, this methodology needs an extended simulation time and is therefore computationally expensive

  7. Helium/solid powder O-ring leakage correlation experiments using a radiotracer

    International Nuclear Information System (INIS)

    UO2 definitely leaked past the O-ring in three of the tests confirming the major results of the previous work. Continuous leakage at these levels may require additional precautions under present regulatory policies. The mechanism and the time and particle size dependence for the leakage are not known, but there is some indication leakage is more likely at low temperatures. It is possible leakage is due to movement of the O-ring during temperature or pressure cycling at the beginning or end of a test. The radiotracer method involves less labor and is much less susceptible to contamination than the previous method. Future work will investigate leakage past lubricated O-rings and time dependence of leakage. 1 reference, 1 table

  8. The Analysis and Comparison of Leakage Inductance in Different Winding Arrangements for Planar Transformer

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Thomsen, Ole Cornelius; Andersen, Michael Andreas E.

    2009-01-01

    The coupling of the windings can be easily increased by using multiply stacked planar windings connection. Interleaving is a well-known technique used to reduce leakage inductance and minimize high-frequency winding losses. The paper aims to analyze leakage inductance based on magneto motive force...... (MMF) and energy distribution in planar transformer and correct the formula of leakage inductance proposed by previous publications. The investigation of different winding arrangements shows significant advantages of interleaving structure. In this work, a novel half turn structure is proposed...... to reduce leakage inductance further. Some important issues are presented to acquire desired leakage inductance. The design and modeling of 1 kW planar transformer is presented. In order to verify the analytical method for leakage inductance in this paper, finite element analysis (FEA) and measurement...

  9. Wind-induced internal pressure response for structure with single windward opening and background leakage

    Institute of Scientific and Technical Information of China (English)

    Shi-ce YU; Wen-juan LOU; Bing-nan SUN

    2008-01-01

    Theoretical analysis and wind tunnel tests were carried out to study wind-induced internal pressure response for the structure with single windward opening and background leakage. Its governing differential equation was derived by the Bernoulli equation in an unsteady-isentropic form. Numerical examples were provided to study the additive damping caused by background leakage in laminar and turbulent flow, and the influence of background leakage on fluctuating internal pressure response was quantized. A series of models for low-rise building with various opening ratios and background leakage were designed and wind tunnel tests were conducted. It is shown that the fluctuating internal pressure reduces when the background leakage are considered and that the effect of background leakage can be predicted accurately by the governing differential equation deduced in this paper.

  10. Leakage Characteristics of Dual-Cannula Fenestrated Tracheostomy Tubes during Positive Pressure Ventilation: A Bench Study.

    Science.gov (United States)

    Berlet, Thomas; Marchon, Mathias

    2016-01-01

    This study compared the leakage characteristics of different types of dual-cannula fenestrated tracheostomy tubes during positive pressure ventilation. Fenestrated Portex® Blue Line Ultra®, TRACOE® twist, or Rüsch® Traceofix® tracheostomy tubes equipped with nonfenestrated inner cannulas were tested in a tracheostomy-lung simulator. Transfenestration pressures and transfenestration leakage rates were measured during positive pressure ventilation. The impact of different ventilation modes, airway pressures, temperatures, and simulated static lung compliance settings on leakage characteristics was assessed. We observed substantial differences in transfenestration pressures and transfenestration leakage rates. The leakage rates of the best performing tubes were Careful tracheostomy tube selection permits the use of fenestrated tracheostomy tubes in patients receiving positive pressure ventilation immediately after stoma formation and minimises the risk of complications caused by transfenestration gas leakage, for example, subcutaneous emphysema. PMID:27073395

  11. In vitro analysis of PDZ-dependent CFTR macromolecular signaling complexes.

    Science.gov (United States)

    Wu, Yanning; Wang, Shuo; Li, Chunying

    2012-08-13

    has been shown to be of functional significance, suggesting that PDZ scaffold proteins may facilitate formation of CFTR macromolecular signaling complexes for specific/selective and efficient signaling in cells(16-18). Multiple biochemical assays have been developed to study CFTR-involving protein interactions, such as co-immunoprecipitation, pull-down assay, pair-wise binding assay, colorimetric pair-wise binding assay, and macromolecular complex assembly assay(16-19,28,29). Here we focus on the detailed procedures of assembling a PDZ motif-dependent CFTR-containing macromolecular complex in vitro, which is used extensively by our laboratory to study protein-protein or domain-domain interactions involving CFTR(16-19,28,29).

  12. Macromolecular crowding: chemistry and physics meet biology (Ascona, Switzerland, 10-14 June 2012).

    Science.gov (United States)

    Foffi, G; Pastore, A; Piazza, F; Temussi, P A

    2013-08-02

    More than 60 years of biochemical and biophysical studies have accustomed us to think of proteins as highly purified entities that act in isolation, more or less freely diffusing until they find their cognate partner to bind to. While in vitro experiments that reproduce these conditions largely remain the only way to investigate the intrinsic properties of molecules, this approach ignores an important factor: in their natural milieu , proteins are surrounded by several other molecules of different chemical nature, and this crowded environment can considerably modify their behaviour. About 40% of the cellular volume on average is occupied by all sorts of molecules. Furthermore, biological macromolecules live and operate in an extremely structured and complex environment within the cell (endoplasmic reticulum, Golgi apparatus, cytoskeletal structures, etc). Hence, to further complicate the picture, the interior of the cell is by no means a simply crowded medium, rather, a most crowded and confining one. In recent times, several approaches have been developed in the attempt to take into account important factors such as the ones mentioned above, at both theoretical and experimental levels, so that this field of research is now emerging as one of the most thriving in molecular and cell biology (see figure 1). [Formula: see text] Figure 1. Left: number of articles containing the word 'crowding' as a keyword limited to the biological and chemical science domains (source: ISI Web of Science). The arrow flags the 2003 'EMBO Workshop on Biological Implications of Macromolecular Crowding' (Embo, 2012). Right: number of citations to articles containing the word 'crowding' limited to the same domains (bars) and an exponential regression curve (source: Elsevier Scopus). To promote the importance of molecular crowding and confinement and provide researchers active in this field an interdisciplinary forum for meeting and exchanging ideas, we recently organized an international

  13. Solid-state NMR in macromolecular systems: insights on how molecular entities move.

    Science.gov (United States)

    Hansen, Michael Ryan; Graf, Robert; Spiess, Hans Wolfgang

    2013-09-17

    The function of synthetic and natural macromolecularsystems critically depends on the packing and dynamics of the individual components of a given system. Not only can solid-state NMR provide structural information with atomic resolution, but it can also provide a way to characterize the amplitude and time scales of motions over broad ranges of length and time. These movements include molecular dynamics, rotational and translational motions of the building blocks, and also the motion of the functional species themselves, such as protons or ions. This Account examines solid-state NMR methods for correlating dynamics and function in a variety of chemical systems. In the early days, scientists thought that the rotationalmotions reflected the geometry of the moving entities. They described these phenomena as jumps about well-defined axes, such as phenyl flips, even in amorphous polymers. Later, they realized that conformational transitions in macromolecules happen in a much more complex way. Because the individual entities do not rotate around well-defined axes, they require much less space. Only recently researchers have appreciated the relative importance of large angle fluctuations of polymers over rotational jumps. Researchers have long considered that cooperative motions might be at work, yet only recently they have clearly detected these motions by NMR in macromolecular and supramolecular systems. In correlations of dynamics and function, local motions do not always provide the mechanism of long-range transport. This idea holds true in ion conduction but also applies to chain transport in polymer melts and semicrystalline polymers. Similar chain motions and ion transport likewise occur in functional biopolymers, systems where solid-state NMR studies are also performed. In polymer science, researchers have appreciated the unique information on molecular dynamics available from advanced solid-state NMR at times, where their colleagues in the biomacromolecular

  14. DISTURBANCE OF THE CARDIOMYOCYTE’S MACROMOLECULAR STRUCTURE IN HEART ALLOGRAFTS AS A SIGN OF CHRONIC REJECTION

    Directory of Open Access Journals (Sweden)

    A. G. Kupriyanova

    2012-01-01

    Full Text Available Chronic rejection, especially cardiac allograft vasculopathy, is a major limiting factor for long-term transplant survival. This process affects not only the blood vessels, but also cardiomyocytes. However, there are extremely few reports on the evaluation of their macromolecular structure state. The aim of the study was to evaluate the structural proteins of cardiomyocytes (actin, myosin, troponin I, titin, desmin, vinculin of heart allografts in different periods after the operation (from 6 days to 15 years. Major changes of macromolecular structure were revealed in late period after transplantation (6 months – 15 years. The contribution of humoral immune response in the process of chronic cardiac allograft rejection was observed: in eight of twelve recipients episodes of acute humoral rejection had been repeatedly registered; disorders of the expression of 5 proteins out of 6 characterized were found in recipients with recurrent and persistent antibody-mediated rejection. 

  15. Distribution and enzymatic activity of heterotrophic bacteria decomposing selected macromolecular compounds in a Baltic Sea sandy beach

    Science.gov (United States)

    Podgórska, B.; Mudryk, Z. J.

    2003-03-01

    The potential capability to decompose macromolecular compounds, and the level of extracellular enzyme activities were determined in heterotrophic bacteria isolated from a sandy beach in Sopot on the Southern Baltic Sea coast. Individual isolates were capable of hydrolysing a wide spectrum of organic macromolecular compounds. Lipids, gelatine, and DNA were hydrolyzed most efficiently. Only a very small percentage of strains were able to decompose cellulose, and no pectinolytic bacteria were found. Except for starch-hydrolysis, no significant differences in the intensity of organic compound decomposition were recorded between horizontal and vertical profiles of the studied beach. Of all the studied extracellular enzymes, alkaline phosphatase, esterase lipase, and leucine acrylaminidase were most active; in contrast, the activity α-fucosidase, α-galactosidase and β-glucouronidase was the weakest. The level of extracellular enzyme activity was similar in both sand layers.

  16. Radiation-induced off-state leakage current in commercial power MOSFETs

    International Nuclear Information System (INIS)

    The total dose hardness of several commercial power MOSFET technologies is examined. After exposure to 20 krad(SiO2) most of the n- and p-channel devices examined in this work show substantial (2 to 6 orders of magnitude) increases in off-state leakage current. For the n-channel devices, the increase in radiation-induced leakage current follows standard behavior for moderately thick gate oxides, i.e., the increase in leakage current is dominated by large negative threshold voltage shifts, which cause the transistor to be partially on even when no bias is applied to the gate electrode. N-channel devices biased during irradiation show a significantly larger leakage current increase than grounded devices. The increase in leakage current for the p-channel devices, however, was unexpected. For the p-channel devices, it is shown using electrical characterization and simulation that the radiation-induced leakage current increase is related to an increase in the reverse bias leakage characteristics of the gated diode which is formed by the drain epitaxial layer and the body. This mechanism does not significantly contribute to radiation-induced leakage current in typical p-channel MOS transistors. The p-channel leakage current increase is nearly identical for both biased and grounded irradiations and therefore has serious implications for long duration missions since even devices which are usually powered off could show significant degradation and potentially fail.

  17. Intrathoracic anastomotic leakage after gastroesophageal cancer resection is associated with increased risk of recurrence

    DEFF Research Database (Denmark)

    Kofoed, Steen C; Calatayud, Dan; Jensen, Lone S;

    2015-01-01

    OBJECTIVE: Intrathoracic anastomotic leakage after intended curative resection for cancer in the esophagus or gastroesophageal junction has a negative impact on long-term survival. The aim of this study was to investigate whether an anastomotic leakage was associated with an increased recurrence ......]: 1.17-2.29, P = .004) and all-cause mortality (HR = 1.57; 95% CI: 1.23-2.05, P cancer resection.......OBJECTIVE: Intrathoracic anastomotic leakage after intended curative resection for cancer in the esophagus or gastroesophageal junction has a negative impact on long-term survival. The aim of this study was to investigate whether an anastomotic leakage was associated with an increased recurrence...

  18. Estimation of leakage power and delay in CMOS circuits using parametric variation

    Directory of Open Access Journals (Sweden)

    Preeti Verma

    2016-09-01

    Full Text Available With the advent of deep-submicron technologies, leakage power dissipation is a major concern for scaling down portable devices that have burst-mode type integrated circuits. In this paper leakage reduction technique HTLCT (High Threshold Leakage Control Transistor is discussed. Using high threshold transistors at the place of low threshold leakage control transistors, result in more leakage power reduction as compared to LCT (leakage control transistor technique but at the scarifies of area and delay. Further, analysis of effect of parametric variation on leakage current and propagation delay in CMOS circuits is performed. It is found that the leakage power dissipation increases with increasing temperature, supply voltage and aspect ratio. However, opposite pattern is noticed for the propagation delay. Leakage power dissipation for LCT NAND gate increases up to 14.32%, 6.43% and 36.21% and delay decreases by 22.5%, 42% and 9% for variation of temperature, supply voltage and aspect ratio. Maximum peak of equivalent output noise is obtained as 127.531 nV/Sqrt(Hz at 400 mHz.

  19. Effects of leakage inductances on magnetically-coupled impedance-source networks

    DEFF Research Database (Denmark)

    Siwakoti, Yam P.; Loh, Poh Chiang; Blaabjerg, Frede;

    2014-01-01

    Coupled inductors have lately been used with impedance-source networks for keeping their shoot-through times short, while providing higher voltage boosts. The parameter that is critical to the operation of such impedance network based converter with coupled inductors is the leakage inductances. H....... However, the role of leakage inductances and its effect on the converter performance is often overlooked. This paper analyzes the effects of leakage inductances and demonstrates experimentally how the presence of leakage inductances degrades the performance of the converter....

  20. 08B1-1: an automated beamline for macromolecular crystallography experiments at the Canadian Light Source.

    Science.gov (United States)

    Fodje, Michel; Grochulski, Pawel; Janzen, Kathryn; Labiuk, Shaunivan; Gorin, James; Berg, Russ

    2014-05-01

    Beamline 08B1-1 is a recently commissioned bending-magnet beamline at the Canadian Light Source. The beamline is designed for automation and remote access. Together with the undulator-based beamline 08ID-1, they constitute the Canadian Macromolecular Crystallography Facility. This paper describes the design, specifications, hardware and software of beamline 08B1-1. A few scientific results using data obtained at the beamline will be highlighted.

  1. DISTURBANCE OF THE CARDIOMYOCYTE’S MACROMOLECULAR STRUCTURE IN HEART ALLOGRAFTS AS A SIGN OF CHRONIC REJECTION

    OpenAIRE

    A. G. Kupriyanova; L. V. Beletskaya; I. M. Ilyinsky; V. A. Zaidenov; N. P. Mozeiko; R. S. Saitgareev; A. Y. Kormer; A. M. Golts; V. M. Zakharevich; S. V. Gautier

    2012-01-01

    Chronic rejection, especially cardiac allograft vasculopathy, is a major limiting factor for long-term transplant survival. This process affects not only the blood vessels, but also cardiomyocytes. However, there are extremely few reports on the evaluation of their macromolecular structure state. The aim of the study was to evaluate the structural proteins of cardiomyocytes (actin, myosin, troponin I, titin, desmin, vinculin) of heart allografts in different periods after the operation (from ...

  2. The influence of hyaluronic acid hydrogel crosslinking density and macromolecular diffusivity on human MSC chondrogenesis and hypertrophy

    OpenAIRE

    Bian, Liming; Hou, Chieh; Tous, Elena; Rai, Reena; Mauck, Robert L.; Burdick, Jason A.

    2012-01-01

    Hyaluronic acid (HA) hydrogels formed via photocrosslinking provide stable 3D hydrogel environments that support the chondrogenesis of mesenchymal stem cells (MSCs). Crosslinking density has a significant impact on the physical properties of hydrogels, including their mechanical stiffness and macromolecular diffusivity. Variations in the HA hydrogel crosslinking density can be obtained by either changes in the HA macromer concentration (1, 3, or 5% w/v at 15 min exposure) or the extent of rea...

  3. Impaired Macromolecular Protein Pools in Fronto-Striato-Thalamic Circuits in Type 2 Diabetes Revealed by Magnetization Transfer Imaging

    OpenAIRE

    Yang, Shaolin; Ajilore, Olusola; Wu, Minjie; Lamar, Melissa; Kumar, Anand

    2014-01-01

    Previous research has shown that type 2 diabetes mellitus (T2DM) is associated with white matter microstructural changes, cognitive impairment, and decreased resting-state functional connectivity and spontaneous brain activity. This study used magnetization transfer imaging to examine, for the first time, the integrity of macromolecular protein pools in fronto-striato-thalamic circuits and its clinical and cognitive correlates in patients with T2DM. T2DM patients without mood disorders (n = 2...

  4. A facile metal-free "grafting-from" route from acrylamide-based substrate toward complex macromolecular combs

    KAUST Repository

    Zhao, Junpeng

    2013-01-01

    High-molecular-weight poly(N,N-dimethylacrylamide-co-acrylamide) was used as a model functional substrate to investigate phosphazene base (t-BuP 4)-promoted metal-free anionic graft polymerization utilizing primary amide moieties as initiating sites. The (co)polymerization of epoxides was proven to be effective, leading to macromolecular combs with side chains being single- or double-graft homopolymer, block copolymer and statistical copolymer. © 2013 The Royal Society of Chemistry.

  5. Modeling of leakage currents in high-k dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Jegert, Gunther Christian

    2012-03-15

    Leakage currents are one of the major bottlenecks impeding the downscaling efforts of the semiconductor industry. Two core devices of integrated circuits, the transistor and, especially, the DRAM storage capacitor, suffer from the increasing loss currents. In this perspective a fundamental understanding of the physical origin of these leakage currents is highly desirable. However, the complexity of the involved transport phenomena so far has prevented the development of microscopic models. Instead, the analysis of transport through the ultra-thin layers of high-permittivity (high-k) dielectrics, which are employed as insulating layers, was carried out at an empirical level using simple compact models. Unfortunately, these offer only limited insight into the physics involved on the microscale. In this context the present work was initialized in order to establish a framework of microscopic physical models that allow a fundamental description of the transport processes relevant in high-k thin films. A simulation tool that makes use of kinetic Monte Carlo techniques was developed for this purpose embedding the above models in an environment that allows qualitative and quantitative analyses of the electronic transport in such films. Existing continuum approaches, which tend to conceal the important physics behind phenomenological fitting parameters, were replaced by three-dimensional transport simulations at the level of single charge carriers. Spatially localized phenomena, such as percolation of charge carriers across pointlike defects, being subject to structural relaxation processes, or electrode roughness effects, could be investigated in this simulation scheme. Stepwise a self-consistent, closed transport model for the TiN/ZrO{sub 2} material system, which is of outmost importance for the semiconductor industry, was developed. Based on this model viable strategies for the optimization of TiN/ZrO{sub 2}/TiN capacitor structures were suggested and problem areas

  6. On leakage and seepage from geological carbon sequestration sites

    Energy Technology Data Exchange (ETDEWEB)

    Oldenburg, C.M.; Unger, A.J.A.; Hepple, R.P.; Jordan, P.D.

    2002-07-18

    Geologic carbon sequestration is one strategy for reducing the rate of increase of global atmospheric carbon dioxide (CO{sub 2} ) concentrations (IEA, 1997; Reichle, 2000). As used here, the term geologic carbon sequestration refers to the direct injection of supercritical CO{sub 2} deep into subsurface target formations. These target formations will typically be either depleted oil and gas reservoirs, or brine-filled permeable formations referred to here as brine formations. Injected CO{sub 2} will tend to be trapped by one or more of the following mechanisms: (1) permeability trapping, for example when buoyant supercritical CO{sub 2} rises until trapped by a confining caprock; (2) solubility trapping, for example when CO{sub 2} dissolves into the aqueous phase in water-saturated formations, or (3) mineralogic trapping, such as occurs when CO{sub 2} reacts to produce stable carbonate minerals. When CO{sub 2} is trapped in the subsurface by any of these mechanisms, it is effectively sequestered away from the atmosphere where it would otherwise act as a greenhouse gas. The purpose of this report is to summarize our work aimed at quantifying potential CO{sub 2} seepage due to leakage from geologic carbon sequestration sites. The approach we take is to present first the relevant properties of CO{sub 2} over the range of conditions from the deep subsurface to the vadose zone (Section 2), and then discuss conceptual models for how leakage might occur (Section 3). The discussion includes consideration of gas reservoir and natural gas storage analogs, along with some simple estimates of seepage based on assumed leakage rates. The conceptual model discussion provides the background for the modeling approach wherein we focus on simulating transport in the vadose zone, the last potential barrier to CO{sub 2} seepage (Section 4). Because of the potentially wide range of possible properties of actual future geologic sequestration sites, we carry out sensitivity analyses by

  7. Passive electrical monitoring and localization of fluid leakages from wells

    Science.gov (United States)

    Revil, A.; Mao, D.; Haas, A. K.; Karaoulis, M.; Frash, L.

    2015-02-01

    Electrokinetic phenomena are a class of cross-coupling phenomena involving the relative displacement between the pore water (together with the electrical diffuse layer) with respect to the solid phase of a porous material. We demonstrate that electrical fields of electrokinetic nature can be associated with fluid leakages from wells. These leakages can be remotely monitored and the resulting signals used to localize their causative source distribution both in the laboratory and in field conditions. The first laboratory experiment (Experiment #1) shows how these electrical fields can be recorded at the surface of a cement block during the leakage of a brine from a well. The measurements were performed with a research-grade medical electroencephalograph and were inverted using a genetic algorithm to localize the causative source of electrical current and therefore, localize the leak in the block. Two snapshots of electrical signals were used to show how the leak evolved over time. The second experiment (Experiment #2) was performed to see if we could localize a pulse water injection from a shallow well in field conditions in the case of a heterogeneous subsurface. We used the same equipment as in Experiment #1 and processed the data with a trend removal algorithm, picking the amplitude from 24 receiver channels just after the water injection. The amplitude of the electric signals changed from the background level indicating that a volume of water was indeed flowing inside the well into the surrounding soil and then along the well. We used a least-square inversion algorithm to invert a snapshot of the electrical potential data at the injection time to localize the source of the self-potential signals. The inversion results show positive potential anomalies in the vicinity of the well. For both experiments, forward numerical simulations of the problem using a finite element package were performed in order to assess the underlying physics of the causative source of the

  8. Modeling of leakage currents in high-k dielectrics

    International Nuclear Information System (INIS)

    Leakage currents are one of the major bottlenecks impeding the downscaling efforts of the semiconductor industry. Two core devices of integrated circuits, the transistor and, especially, the DRAM storage capacitor, suffer from the increasing loss currents. In this perspective a fundamental understanding of the physical origin of these leakage currents is highly desirable. However, the complexity of the involved transport phenomena so far has prevented the development of microscopic models. Instead, the analysis of transport through the ultra-thin layers of high-permittivity (high-k) dielectrics, which are employed as insulating layers, was carried out at an empirical level using simple compact models. Unfortunately, these offer only limited insight into the physics involved on the microscale. In this context the present work was initialized in order to establish a framework of microscopic physical models that allow a fundamental description of the transport processes relevant in high-k thin films. A simulation tool that makes use of kinetic Monte Carlo techniques was developed for this purpose embedding the above models in an environment that allows qualitative and quantitative analyses of the electronic transport in such films. Existing continuum approaches, which tend to conceal the important physics behind phenomenological fitting parameters, were replaced by three-dimensional transport simulations at the level of single charge carriers. Spatially localized phenomena, such as percolation of charge carriers across pointlike defects, being subject to structural relaxation processes, or electrode roughness effects, could be investigated in this simulation scheme. Stepwise a self-consistent, closed transport model for the TiN/ZrO2 material system, which is of outmost importance for the semiconductor industry, was developed. Based on this model viable strategies for the optimization of TiN/ZrO2/TiN capacitor structures were suggested and problem areas that may arise

  9. A decade of user operation on the macromolecular crystallography MAD beamline ID14-4 at the ESRF.

    Science.gov (United States)

    McCarthy, Andrew A; Brockhauser, Sandor; Nurizzo, Didier; Theveneau, Pascal; Mairs, Trevor; Spruce, Darren; Guijarro, Matias; Lesourd, Marc; Ravelli, Raimond B G; McSweeney, Sean

    2009-11-01

    ID14-4 at the ESRF is the first tunable undulator-based macromolecular crystallography beamline that can celebrate a decade of user service. During this time ID14-4 has not only been instrumental in the determination of the structures of biologically important molecules but has also contributed significantly to the development of various instruments, novel data collection schemes and pioneering radiation damage studies on biological samples. Here, the evolution of ID14-4 over the last decade is presented, and some of the major improvements that were carried out in order to maintain its status as one of the most productive macromolecular crystallography beamlines are highlighted. The experimental hutch has been upgraded to accommodate a high-precision diffractometer, a sample changer and a large CCD detector. More recently, the optical hutch has been refurbished in order to improve the X-ray beam quality on ID14-4 and to incorporate the most modern and robust optical elements used at other ESRF beamlines. These new optical elements will be described and their effect on beam stability discussed. These studies may be useful in the design, construction and maintenance of future X-ray beamlines for macromolecular crystallography and indeed other applications, such as those planned for the ESRF upgrade.

  10. A decade of user operation on the macromolecular crystallography MAD beamline ID14-4 at the ESRF

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, Andrew A., E-mail: andrewmc@embl.fr; Brockhauser, Sandor [European Molecular Biology Laboratory, 6 rue Jules Horowitz, BP 181, 38042 Grenoble (France); Unit of Virus Host Cell Interactions, UJF-EMBL-CNRS, UMI 3265, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9 (France); Nurizzo, Didier; Theveneau, Pascal; Mairs, Trevor; Spruce, Darren; Guijarro, Matias; Lesourd, Marc [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, BP 220, 38042 Grenoble (France); Ravelli, Raimond B. G. [European Molecular Biology Laboratory, 6 rue Jules Horowitz, BP 181, 38042 Grenoble (France); McSweeney, Sean [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, BP 220, 38042 Grenoble (France)

    2009-11-01

    The improvement of the X-ray beam quality achieved on ID14-4 by the installation of new X-ray optical elements is described. ID14-4 at the ESRF is the first tunable undulator-based macromolecular crystallography beamline that can celebrate a decade of user service. During this time ID14-4 has not only been instrumental in the determination of the structures of biologically important molecules but has also contributed significantly to the development of various instruments, novel data collection schemes and pioneering radiation damage studies on biological samples. Here, the evolution of ID14-4 over the last decade is presented, and some of the major improvements that were carried out in order to maintain its status as one of the most productive macromolecular crystallography beamlines are highlighted. The experimental hutch has been upgraded to accommodate a high-precision diffractometer, a sample changer and a large CCD detector. More recently, the optical hutch has been refurbished in order to improve the X-ray beam quality on ID14-4 and to incorporate the most modern and robust optical elements used at other ESRF beamlines. These new optical elements will be described and their effect on beam stability discussed. These studies may be useful in the design, construction and maintenance of future X-ray beamlines for macromolecular crystallography and indeed other applications, such as those planned for the ESRF upgrade.

  11. Neutron leakage measurements from a medical linear accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Palta, J.R.; Hogstrom, K.R.; Tannanonta, C.

    1984-07-01

    The McCall method has been used to measure neutron leakage from the Mevatron 77, 18- and 15-MV photon beams. Gold foil activation has been used employing a beta counting technique for the 18-MV beam and a gamma counting technique for both the 18- and 15-MV beam. The two counting techniques were used to evaluate their relative merit. The measurements were made at various locations in the patient-treatment plane for different field sizes. The results show that the thermal-neutron dose equivalent contributes only about 1%--2% of the total neutron dose equivalent. At 100 cm, the neutron dose equivalent for the 18-MV beam is approximately six times that of the 15-MV beam, slightly exceeding the 0.1% of the useful beam criteria used by some of the regulatory agencies. In light of the uncertainty in fluence to dose equivalent conversion factors, the increased dose equivalent above 0.1% is insignificant.

  12. Pressured liquid chlorine leakage accident simulation in highway tunnel

    Directory of Open Access Journals (Sweden)

    LI Jianfeng, LIU Mao, WANG Wei

    2010-03-01

    Full Text Available With the national economic development, China's transportation infrastructure has also made great progress, particularly in the highway. How to reduce the accident consequence that occurred in the highway tunnel has been the tropical topic in China. The liquid Chlorine accidental leakage in highway tunnel was exemplified for the poisonous gas dispersion consequence analysis using computational fluid dynamics. First, the GAMBIT code was used to create geometrical models and generate meshes. Second, by using the FLUENT code, the Chlorine gas dispersion in the highway tunnel was simulated and the scenarios with different leak sources were discussed. Case study shows that the FLUENT code was useful on the simulation of gas dispersion in highway tunnel that serves the prerequisite for the further research.

  13. NUMERICAL ANALYSIS OF LEAKAGE FLOW THROUGH TWO LABYRINTH SEALS

    Institute of Scientific and Technical Information of China (English)

    WANG Wei-zhe; LIU Ying-zheng; JIANG Pu-ning; CHEN Han-ping

    2007-01-01

    The leakage flow through two labyrinth seals, e.g the interlocking seal and the stepped seal, was numerically investigated. Preliminary calculation of the seal-cavity averaged pressure by using the one-dimensional control volume method showed favorable agreement with the experimental measurements. Subsequently, in-depth understanding of the fluid flow through the labyrinth seals was obtained by employing Computational Fluid Dynamics (CFD) and turbulence model, which resulted in a potential wealth of information like the streamline pattern, velocity vector field, and distribution of turbulent kinetic energy and static pressure. At the clearance of the seal the turbulent kinetic energy reached the peak value, while in the bulk region of the cavities it decayed fast. The static pressure rapidly dropped as the fluid flow went through the clearance; no distinct difference of the static pressure was inspected in the cavities. Also noted from the numerical results was that the stepped seal showed better sealing performance than the interlocking seal.

  14. Modern diagnostic systems for loose parts, vibration and leakage monitoring

    International Nuclear Information System (INIS)

    The modern diagnostic systems for loose parts, vibration and leakage monitoring of Siemens marked improvements in signal detection, ease of operation, and the display of information. The paper gives an overview on: Loose parts monitoring system KUeS '95 - a computer-based system. The knowledge and experience about loose parts detection incorporated into this system can be characterized as ''intelligence''. Vibration monitoring system SUeS '95 - a fully automated system for early detection of changes in the vibration patterns of the reactor coolant system components and reactor pressure vessel internals. Leak detection system FLUeS - a system that detects even small leaks in steam-carrying components and very accurately determines their location. Leaks are detected on the moisture distribution in a sample air column into which the escaping steam locally diffuses. All systems described represent the latest state of technology. Nevertheless a considerable amount of operational experience can be reported. (author). 5 refs, 10 figs

  15. Quench tank in-leakage diagnosis at St. Lucie

    Energy Technology Data Exchange (ETDEWEB)

    Price, J.E.; Au-Yang, M.K.; Beckner, D.A.; Vickery, A.N.

    1996-12-01

    In February 1995, leakage into the quench tank of the St. Lucie Nuclear Station Unit 1 was becoming an operational concern. This internal leak resulted in measurable increases in both the temperature and level of the quench tank water, and was so severe that, if the trend continued, plant shut down would be necessary. Preliminary diagnosis based on in-plant instrumentation indicated that any one of 11 valves might be leaking into the quench tank. This paper describes the joint effort by two teams of engineers--one from Florida Power & Light, the other from Framatome Technologies--to identify the sources of the leak, using the latest technology developed for valve diagnosis.

  16. Research on airborne infrared leakage detection of natural gas pipeline

    Science.gov (United States)

    Tan, Dongjie; Xu, Bin; Xu, Xu; Wang, Hongchao; Yu, Dongliang; Tian, Shengjie

    2011-12-01

    An airborne laser remote sensing technology is proposed to detect natural gas pipeline leakage in helicopter which carrying a detector, and the detector can detect a high spatial resolution of trace of methane on the ground. The principle of the airborne laser remote sensing system is based on tunable diode laser absorption spectroscopy (TDLAS). The system consists of an optical unit containing the laser, camera, helicopter mount, electronic unit with DGPS antenna, a notebook computer and a pilot monitor. And the system is mounted on a helicopter. The principle and the architecture of the airborne laser remote sensing system are presented. Field test experiments are carried out on West-East Natural Gas Pipeline of China, and the results show that airborne detection method is suitable for detecting gas leak of pipeline on plain, desert, hills but unfit for the area with large altitude diversification.

  17. [A mobile sensor for remote detection of natural gas leakage].

    Science.gov (United States)

    Zhang, Shuai; Liu, Wen-qing; Zhang, Yu-jun; Kan, Rui-feng; Ruan, Jun; Wang, Li-ming; Yu, Dian-qiang; Dong, Jin-ting; Han, Xiao-lei; Cui, Yi-ben; Liu, Jian-guo

    2012-02-01

    The detection of natural gas pipeline leak becomes a significant issue for body security, environmental protection and security of state property. However, the leak detection is difficult, because of the pipeline's covering many areas, operating conditions and complicated environment. A mobile sensor for remote detection of natural gas leakage based on scanning wavelength differential absorption spectroscopy (SWDAS) is introduced. The improved soft threshold wavelet denoising was proposed by analyzing the characteristics of reflection spectrum. And the results showed that the signal to noise ratio (SNR) was increased three times. When light intensity is 530 nA, the minimum remote sensitivity will be 80 ppm x m. A widely used SWDAS can make quantitative remote sensing of natural gas leak and locate the leak source precisely in a faster, safer and more intelligent way. PMID:22512213

  18. Structural and leakage integrity of tubes affected by circumferential cracking

    Energy Technology Data Exchange (ETDEWEB)

    Hernalsteen, P. [TRACTEBEL, Brussels (Belgium)

    1997-02-01

    In this paper the author deals with the notion that circumferential cracks are generally considered unacceptable. He argues for the need to differentiate two facets of such cracks: the issue of the size and growth rate of a crack; and the issue of the structural strength and leakage potential of the tube in the presence of the crack. In this paper the author tries to show that the second point is not a major concern for such cracks. The paper presents data on the structural strength or burst pressure characteristics of steam generator tubes derived from models and data bases of experimental work. He also presents a leak rate model, and compares the performance of circumferential and axial cracks as far as burst strength and leak rate. The final conclusion is that subject to improvement in NDE capabilities (sizing, detection, growth), that Steam Generator Defect Specific Management can be used to allow circumferentially degraded tubes to remain in service.

  19. Evaluation of Surface Cracks Using Magnetic Flux Leakage Testing

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The magnetic field distribution characteristics of surface cracks with various widths are discussed based on finite element (FEM) results. The crack depth was 0.20 mm, the width range was from 0.02 to 1.00 mm. The results showed that crack width and lift-off (the distance between surface and sensor) will influence signals. Discussed in this paper is the influence of various lift-off parameters on the peak to peak values of the normal component in magnetic flux leakage testing. The effects can be applied to evaluate surface breaking cracks of different widths and depths.An idea is presented to smooth narrow, sharp crack tips using alternating current (AC) field magnetization.

  20. A magnetic flux leakage NDE system for CANDU feeder pipes

    Science.gov (United States)

    Mak, Thomas Don

    This work examines the application of different magnetic flux leakage (MFL) inspection concepts to the non destructive evaluation (NDE) of residual (elastic) stresses in CANDURTM reactor feeder pipes. The stress sensitivity of three MFL inspection techniques was examined with flat plate samples, with stress-induced magnetic anisotropy (SMA) demonstrating the greatest stress sensitivity. A prototype SMA testing system was developed to apply magnetic NDE to feeders. The system consists of a flux controller that incorporates feedback from a wire coil and a Hall sensor (FCV2), and a magnetic anisotropy prototype (MAP) probe. The combination of FCV2 and the MAP probe was shown to provide SMA measurements on feeder pipe samples and predict stresses from SMA measurements with a mean accuracy of +/-38MPa.

  1. Moisture Risk in Unvented Attics Due to Air Leakage Paths

    Energy Technology Data Exchange (ETDEWEB)

    Prahl, D.; Shaffer, M.

    2014-11-01

    IBACOS completed an initial analysis of moisture damage potential in an unvented attic insulated with closed-cell spray polyurethane foam. To complete this analysis, the research team collected field data, used computational fluid dynamics to quantify the airflow rates through individual airflow (crack) paths, simulated hourly flow rates through the leakage paths with CONTAM software, correlated the CONTAM flow rates with indoor humidity ratios from Building Energy Optimization software, and used Warme und Feuchte instationar Pro two-dimensional modeling to determine the moisture content of the building materials surrounding the cracks. Given the number of simplifying assumptions and numerical models associated with this analysis, the results indicate that localized damage due to high moisture content of the roof sheathing is possible under very low airflow rates. Reducing the number of assumptions and approximations through field studies and laboratory experiments would be valuable to understand the real-world moisture damage potential in unvented attics.

  2. Moisture Risk in Unvented Attics Due to Air Leakage Paths

    Energy Technology Data Exchange (ETDEWEB)

    Prahl, D. [IBACOS, Inc., Pittsburgh, PA (United States); Shaffer, M. [IBACOS, Inc., Pittsburgh, PA (United States)

    2014-11-01

    IBACOS completed an initial analysis of moisture damage potential in an unvented attic insulated with closed-cell spray polyurethane foam. To complete this analysis, the research team collected field data, used computational fluid dynamics to quantify the airflow rates through individual airflow (crack) paths, simulated hourly flow rates through the leakage paths with CONTAM software, correlated the CONTAM flow rates with indoor humidity ratios from Building Energy Optimization software, and used Wärme und Feuchte instationär Pro two-dimensional modeling to determine the moisture content of the building materials surrounding the cracks. Given the number of simplifying assumptions and numerical models associated with this analysis, the results indicate that localized damage due to high moisture content of the roof sheathing is possible under very low airflow rates. Reducing the number of assumptions and approximations through field studies and laboratory experiments would be valuable to understand the real-world moisture damage potential in unvented attics.

  3. Dynamic modeling of a solar hydrogen system under leakage conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, J.J. [Graduate Institute of Greenergy Technology, National University of Tainan, Tainan (China); Chang, W.R. [Department of Landscape Architecture, Chung-Hua University, Hsinchu 300 (China); Su, A. [Department of Mechanical Engineering and Fuel Cell Center, Yuan Ze University, Taoyuan (China)

    2008-07-15

    Dynamic behaviors of an integrated solar hydrogen system have been modeled mathematically, which is based on a combination of fundamental theories of thermodynamics, mass transfer, fluid dynamics, and empirical electrochemical relationships. The model considers solar hydrogen system to be composed of three subsystems, i.e., solar cells, an electrolyzer, and a hydrogen tank. An additional pressure switch model is presented to visualize the hydrogen storage dynamics under a leakage condition. Validation of the solar hydrogen model system is evaluated according to the measured data from the manufacturer's data. Then, the overall was simulated by using solar irradiation as the primary energy input and hydrogen as energy storage for one-day operation. Finally, electrical characteristics and efficiencies of each subsystem as well as the entire system are presented and discussed. (author)

  4. Macromolecular scaffolding: the relationship between nanoscale architecture and function in multichromophoric arrays for organic electronics.

    Science.gov (United States)

    Palermo, Vincenzo; Schwartz, Erik; Finlayson, Chris E; Liscio, Andrea; Otten, Matthijs B J; Trapani, Sara; Müllen, Klaus; Beljonne, David; Friend, Richard H; Nolte, Roeland J M; Rowan, Alan E; Samorì, Paolo

    2010-02-23

    The optimization of the electronic properties of molecular materials based on optically or electrically active organic building blocks requires a fine-tuning of their self-assembly properties at surfaces. Such a fine-tuning can be obtained on a scale up to 10 nm by mastering principles of supramolecular chemistry, i.e., by using suitably designed molecules interacting via pre-programmed noncovalent forces. The control and fine-tuning on a greater length scale is more difficult and challenging. This Research News highlights recent results we obtained on a new class of macromolecules that possess a very rigid backbone and side chains that point away from this backbone. Each side chain contains an organic semiconducting moiety, whose position and electronic interaction with neighboring moieties are dictated by the central macromolecular scaffold. A combined experimental and theoretical approach has made it possible to unravel the physical and chemical properties of this system across multiple length scales. The (opto)electronic properties of the new functional architectures have been explored by constructing prototypes of field-effect transistors and solar cells, thereby providing direct insight into the relationship between architecture and function.

  5. The Effect of Attractive Interactions and Macromolecular Crowding on Crystallins Association.

    Directory of Open Access Journals (Sweden)

    Jiachen Wei

    Full Text Available In living systems proteins are typically found in crowded environments where their effective interactions strongly depend on the surrounding medium. Yet, their association and dissociation needs to be robustly controlled in order to enable biological function. Uncontrolled protein aggregation often causes disease. For instance, cataract is caused by the clustering of lens proteins, i.e., crystallins, resulting in enhanced light scattering and impaired vision or blindness. To investigate the molecular origins of cataract formation and to design efficient treatments, a better understanding of crystallin association in macromolecular crowded environment is needed. Here we present a theoretical study of simple coarse grained colloidal models to characterize the general features of how the association equilibrium of proteins depends on the magnitude of intermolecular attraction. By comparing the analytic results to the available experimental data on the osmotic pressure in crystallin solutions, we identify the effective parameters regimes applicable to crystallins. Moreover, the combination of two models allows us to predict that the number of binding sites on crystallin is small, i.e. one to three per protein, which is different from previous estimates. We further observe that the crowding factor is sensitive to the size asymmetry between the reactants and crowding agents, the shape of the protein clusters, and to small variations of intermolecular attraction. Our work may provide general guidelines on how to steer the protein interactions in order to control their association.

  6. Optimizing the spatial distribution of dose in X-ray macromolecular crystallography.

    Science.gov (United States)

    Zeldin, Oliver B; Gerstel, Markus; Garman, Elspeth F

    2013-01-01

    X-ray data collection for macromolecular crystallography can lead to highly inhomogeneous distributions of dose within the crystal volume for cases when the crystal is larger than the beam or when the beam is non-uniform (gaussian-like), particularly when crystal rotation is fully taken into account. Here the spatial distribution of dose is quantitatively modelled in order to compare the effectiveness of two dose-spreading data-collection protocols: helical scanning and translational collection. Their effectiveness in reducing the peak dose per unit diffraction is investigated via simulations for four common crystal shapes (cube, plate, long and short needles) and beams with a wide range of full width half maximum values. By inspection of the chosen metric, it is concluded that the optimum strategy is always to use as flat (top-hat) a beam as possible and to either match the beam size in both dimensions to the crystal, or to perform a helical scan with a beam which is narrow along the rotation axis and matched to the crystal size along the perpendicular axis. For crystal shapes where this is not possible, the reduction in peak dose per unit diffraction achieved through dose spreading is quantified and tabulated as a reference for experimenters.

  7. Visualization of X-ray Beam Using CdWO4 Crystal for Macromolecular Crystallography

    Directory of Open Access Journals (Sweden)

    Kazimierz J. Gofron

    2011-12-01

    Full Text Available In synchrotron diffraction experiments, it is typically assumed that the X-ray beam at the sample position is uniform, stable and has dimensions that are controlled by the focus and slits settings. As might be expected, this process is much more complex. We present here an investigation of the properties of a synchrotron X-ray beam at the sample position. The X-ray beam is visualized with a single crystal scintillator that converts X-ray photons into visible light photons, which can be imaged using Structure Biology Center (SBC on-axis and off-axis microscope optics. The X-ray penetration is dependent on the composition of the scintillator (especially the effective Z, and X-ray energy. Several scintillators have been used to visualize X-ray beams. Here we compare CdWO4, PbWO4, Bi4Ge3O12, Y3Al5O12:Ce (YAG:Ce, and Gd2O2S:Tb (phosphor. We determined that scintillator crystals made of CdWO4 and similar high-Z materials are best suited for the energy range (7–20 keV and are most suitable for beam visualization for macromolecular crystallography applications. These scintillators show excellent absorption, optical, and mechanical properties.

  8. Tailoring Phase Behavior and Mechanical Properties in Thermoplastic Elastomers through Block Sequence and Macromolecular Architecture

    Science.gov (United States)

    Burns, Adam; Register, Richard

    2015-03-01

    Block copolymers exhibit unique properties which depend not only on the identities of the constituent blocks but also the block sequence and macromolecular architecture. Thermoplastic elastomers (TPEs) are a prime example. In TPEs the arrangement of glassy end blocks flanking a long rubbery midblock gives rise to a physically cross-linked, elastic solid. Exchanging the glassy blocks for crystalline blocks can improve the processability and solvent resistance, but adversely affects the mechanical performance. The block sequence crystalline-glassy-rubbery-glassy-crystalline has been developed to combine the advantages of both crystalline and glassy blocks. Careful selection of block lengths produces materials in which the order-disorder transition temperature lies below the melting point of the crystalline block, ensuring that the melt will be homogeneous above the melting point. Access to single-phase melts provides a large reduction in viscosity and elasticity over conventional TPEs, which remain microphase-separated in the melt. Inserting the glassy blocks between the crystalline and rubbery blocks produces a vitreous layer surrounding the crystalline domains, which improves the room-temperature mechanical performance. Incorporating the crystalline-glassy-rubbery motif into the arms of star block copolymers adds another level of control. The star architecture introduces a permanent cross-link at the center of the star without appreciably affecting the phase behavior.

  9. FitEM2EM--tools for low resolution study of macromolecular assembly and dynamics.

    Directory of Open Access Journals (Sweden)

    Ziv Frankenstein

    Full Text Available Studies of the structure and dynamics of macromolecular assemblies often involve comparison of low resolution models obtained using different techniques such as electron microscopy or atomic force microscopy. We present new computational tools for comparing (matching and docking of low resolution structures, based on shape complementarity. The matched or docked objects are represented by three dimensional grids where the value of each grid point depends on its position with regard to the interior, surface or exterior of the object. The grids are correlated using fast Fourier transformations producing either matches of related objects or docking models depending on the details of the grid representations. The procedures incorporate thickening and smoothing of the surfaces of the objects which effectively compensates for differences in the resolution of the matched/docked objects, circumventing the need for resolution modification. The presented matching tool FitEM2EMin successfully fitted electron microscopy structures obtained at different resolutions, different conformers of the same structure and partial structures, ranking correct matches at the top in every case. The differences between the grid representations of the matched objects can be used to study conformation differences or to characterize the size and shape of substructures. The presented low-to-low docking tool FitEM2EMout ranked the expected models at the top.

  10. ‘Broken symmetries’ in macromolecular crystallography: phasing from unmerged data

    International Nuclear Information System (INIS)

    Site-specific radiation damage and anisotropy of anomalous scattering can induce intensity differences in symmetry-related reflections. If the data are kept unmerged, these symmetry-breaking effects can become a source of phase information. The space-group symmetry of a crystal structure imposes a point-group symmetry on its diffraction pattern, giving rise to so-called symmetry-equivalent reflections. Instances in macromolecular crystallography are discussed in which the symmetry in reciprocal space is broken, i.e. where symmetry-related reflections are no longer equivalent. Such a situation occurs when the sample suffers from site-specific radiation damage during the X-ray measurements. Another example of broken symmetry arises from the polarization anisotropy of anomalous scattering. In these cases, the genuine intensity differences between symmetry-related reflections can be exploited to yield phase information in the structure-solution process. In this approach, the usual separation of the data merging and phasing steps is abandoned. The data are kept unmerged down to the Harker construction, where the symmetry-breaking effects are explicitly modelled and refined and become a source of supplementary phase information

  11. Using support vector machines to improve elemental ion identification in macromolecular crystal structures

    Energy Technology Data Exchange (ETDEWEB)

    Morshed, Nader [University of California, Berkeley, CA 94720 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Echols, Nathaniel, E-mail: nechols@lbl.gov [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Adams, Paul D., E-mail: nechols@lbl.gov [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); University of California, Berkeley, CA 94720 (United States)

    2015-05-01

    A method to automatically identify possible elemental ions in X-ray crystal structures has been extended to use support vector machine (SVM) classifiers trained on selected structures in the PDB, with significantly improved sensitivity over manually encoded heuristics. In the process of macromolecular model building, crystallographers must examine electron density for isolated atoms and differentiate sites containing structured solvent molecules from those containing elemental ions. This task requires specific knowledge of metal-binding chemistry and scattering properties and is prone to error. A method has previously been described to identify ions based on manually chosen criteria for a number of elements. Here, the use of support vector machines (SVMs) to automatically classify isolated atoms as either solvent or one of various ions is described. Two data sets of protein crystal structures, one containing manually curated structures deposited with anomalous diffraction data and another with automatically filtered, high-resolution structures, were constructed. On the manually curated data set, an SVM classifier was able to distinguish calcium from manganese, zinc, iron and nickel, as well as all five of these ions from water molecules, with a high degree of accuracy. Additionally, SVMs trained on the automatically curated set of high-resolution structures were able to successfully classify most common elemental ions in an independent validation test set. This method is readily extensible to other elemental ions and can also be used in conjunction with previous methods based on a priori expectations of the chemical environment and X-ray scattering.

  12. Involvement of lysosomes in the uptake of macromolecular material by bloodstream forms of Trypanosoma brucei.

    Science.gov (United States)

    Opperdoes, F R; Van Roy, J

    1982-09-01

    To investigate whether the lysosomes of Trypanosoma brucei are capable of uptake of macromolecules after internalization by the cell, we used Triton WR-1339, a non-digestible macromolecular compound, which is known to cause a marked decrease in the density of hepatic lysosomes due to massive intralysosomal storage. Intraperitoneal administration of 0.4 g/kg Triton WR-1339 to rats infected with T. brucei led to the development of a large vacuole in the trypanosomes between nucleus and kinetoplast within 22 h. Higher doses (2 g/kg) led to the disappearance of the trypanosomes from the blood and resulted in permanent cures (greater than 100 days). Lysosomes isolated from the trypanosomes of animals treated with a sub-curative dose showed a decrease in equilibrium density of 0.03 g/cm3 in sucrose gradients. These lysosomes were partly damaged as evidenced by a reduction in latency and an increase in the non-sedimentable part of lysosomal enzymes. We conclude that acid proteinase and alpha-mannosidase-containing organelles of T. brucei take up exogenous macromolecules and must therefore be considered as true lysosomes and that Triton WR-1339 acts in T. brucei as a true lysosomotropic drug. Its trypanocidal action probably results from an interference with lysosomal function.

  13. MRI macromolecular contrast agents as indicators of changed tumor blood flow

    International Nuclear Information System (INIS)

    Background. A rapid mapping technique derived from dynamic contrast enhanced MRI data was used to identify and characterize reduction of blood flow in fibrosarcoma SA-1 tumors treated either by application of electric pulses or vinblastine. Materials and methods. Tissue permeability surface area product (PS) and fractional blood volume (BV) were calculated on a pixel-by-pixel basis using dynamic MRI intensity data after administration of gadomer- 17 or polylysine-Gd-DTPA; prototypic macromolecular contrast agents designed for blood pool enhancement. PS and BV values of untreated tumors were compared to those of tumors treated by local application of 8 electric pulses (amplitude/distance ratio, 1300 V/cm; duration, 100 μs, frequency, 1 Hz) percutaneously to the tumor or by systemic administration of vinblastine (2.5 mg/kg). Results. Both treatments transiently, but significantly reduced tumor blood flow, application of electric pulses to the tumors being by 40% more effective in reducing tumor blood flow than systemic administration of vinblastine. PS and BV values derived with polylysine-Gd-DTPA-enhanced MRI were lower compared to those with gadomer-17, due to larger molecular size. Interestingly, Gd-DTPA-enhanced MRI did not show any significant changes of PS and BV between untreated and treated tumors. Conclusion. This study demonstrates that dynamic contrast enhanced MRI can be effectively used to qualitatively monitor tumor blood flow, and quantitatively by means of BV and PS. (author)

  14. Effects of macromolecular crowding and DNA looping on gene regulation kinetics

    Science.gov (United States)

    Li, Gene-Wei; Berg, Otto G.; Elf, Johan

    2009-04-01

    DNA-binding proteins control how genomes function. The theory of facilitated diffusion explains how DNA-binding proteins can find targets apparently faster than the diffusion limit by using reduced dimensionality-combining three-dimensional (3D) diffusion through cytoplasm with 1D sliding along DNA (refs 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15). However, it does not include a description of macromolecular crowding on DNA as observed in living cells. Here, we show that such a physical constraint to sliding greatly reduces the search speed, in agreement with single-molecule measurements. Interestingly, the generalized theory also reveals significant insights into the design principles of biology. First, it places a hard constraint on the total number of DNA-binding proteins per cell. Remarkably, the number measured for Escherichia coli fits within the optimal range. Secondly, it defines a new role for DNA looping, a ubiquitous topological motif in genomes. DNA looping can speed up the search process by bypassing proteins that block the sliding track close to the target.

  15. IMAGINE: first neutron protein structure and new capabilities for neutron macromolecular crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Munshi, Parthapratim [ORNL; Myles, Dean A A [ORNL; Robertson, Lee [ORNL; Stoica, Alexandru Dan [ORNL; Crow, Lowell [ORNL; Kovalevskyi, Andrii Y [ORNL; Koritsanszky, Tibor S [ORNL; Chakoumakos, Bryan C [ORNL; Blessing, Robert [Hauptman-Woodward Medical Research Institute; Meilleur, Flora [ORNL

    2013-01-01

    We report the first high resolution neutron protein structure of perdeuterated rubredoxin from Pyrococcus furiosus (PfRd) determined using the new IMAGINE macromolecular neutron crystallography instrument at the Oak Ridge National Laboratory. Neutron diffraction data extending to 1.65 resolution were collected from a relatively small 0.7 mm3 PfRd crystal using 2.5 days (60 h) of beam time. The refined structure contains 371 out of 391, or 95%, of the deuterium atoms of the protein, and 58 solvent molecules. The IMAGINE instrument is designed to provide neutron data at or near atomic resolutions (1.5 ) from crystals with volume < 1.0 mm3 and with unit cell edges < 100 . Beam line features include elliptical focusing mirrors that deliver 3x107 n s-1 cm-2 into a 3.5 x 2.0 mm2 focal spot at the sample position, and variable short and long wavelength cutoff optics that provide automated exchange between multiple wavelength configurations ( min=2.0 , 2.8 , 3.3 - max =3.0 , 4.0 , 4.5 , ~20 ). Notably, the crystal used to collect this PfRd data is 5-10 times smaller than has been previously reported.

  16. Olfactory nerve transport of macromolecular drugs to the brain. A problem in olfactory impaired patients

    International Nuclear Information System (INIS)

    Nasal administration of macromolecular drugs (including peptides and nanoparticles) has the potential to enable drug delivery system beyond the blood brain barrier (BBB) via olfactory nerve transport. Basic research on drug deliver systems to the brain via nasal administration has been well reported. Insulin-like growth factor-I (IGF-I) is associated with the development and growth of the central nervous system. Clinical application of IGF-I with nasal administration is intended to enable drug delivery to brain through the BBB. Uptake of IGF-I in the olfactory bulb and central nervous system increased according to the dosage of nasally administered IGF-I in normal ICR mice, however IGF-I uptake in the trigeminal nerve remained unchanged. Olfactory nerve transport is important for the delivery of nasally administered IGF-I to the brain in vivo. Because a safe olfactory nerve tracer has not been clinically available, olfactory nerve transport has not been well studied in humans. Nasal thallium-201 (201Tl) administration has been safely used to assess the direct pathway to the brain via the nose in healthy volunteers with a normal olfactory threshold. 201Tl olfactory nerve transport has recently been shown to decrease in patients with hyposmia. The olfactory nerve transport function in patients with olfactory disorders will be determined using 201Tl olfacto-scintigraphy for the exclusion of candidates in a clinical trial to assess the usefulness of nasal administration of IGF-I. (author)

  17. Synthesis and Self-Assembly of Amphiphilic Triblock Terpolymers with Complex Macromolecular Architecture

    KAUST Repository

    Polymeropoulos, George

    2015-11-25

    Two star triblock terpolymers (PS-b-P2VP-b-PEO)3 and one dendritic-like terpolymer [PS-b-P2VP-b-(PEO)2]3 of PS (polystyrene), P2VP (poly(2-vinylpyridine)), and PEO (poly(ethylene oxide)), never reported before, were synthesized by combining atom transfer radical and anionic polymerizations. The synthesis involves the transformation of the -Br groups of the previously reported Br-terminated 3-arm star diblock copolymers to one or two -OH groups, followed by anionic polymerization of ethylene oxide to afford the star or dendritic structure, respectively. The well-defined structure of the terpolymers was confirmed by static light scattering, size exclusion chromatography, and NMR spectroscopy. The self-assembly in solution and the morphology in bulk of the terpolymers, studied by dynamic light scattering and transmission electron microscopy, respectively, reveal new insights in the phase separation of these materials with complex macromolecular architecture. © 2015 American Chemical Society.

  18. Temperature sensitivity of soil microbial communities: An application of macromolecular rate theory to microbial respiration

    Science.gov (United States)

    Alster, Charlotte J.; Koyama, Akihiro; Johnson, Nels G.; Wallenstein, Matthew D.; Fischer, Joseph C.

    2016-06-01

    There is compelling evidence that microbial communities vary widely in their temperature sensitivity and may adapt to warming through time. To date, this sensitivity has been largely characterized using a range of models relying on versions of the Arrhenius equation, which predicts an exponential increase in reaction rate with temperature. However, there is growing evidence from laboratory and field studies that observe nonmonotonic responses of reaction rates to variation in temperature, indicating that Arrhenius is not an appropriate model for quantitatively characterizing temperature sensitivity. Recently, Hobbs et al. (2013) developed macromolecular rate theory (MMRT), which incorporates thermodynamic temperature optima as arising from heat capacity differences between isoenzymes. We applied MMRT to measurements of respiration from soils incubated at different temperatures. These soils were collected from three grassland sites across the U.S. Great Plains and reciprocally transplanted, allowing us to isolate the effects of microbial community type from edaphic factors. We found that microbial community type explained roughly 30% of the variation in the CO2 production rate from the labile C pool but that temperature and soil type were most important in explaining variation in labile and recalcitrant C pool size. For six out of the nine soil × inoculum combinations, MMRT was superior to Arrhenius. The MMRT analysis revealed that microbial communities have distinct heat capacity values and temperature sensitivities sometimes independent of soil type. These results challenge the current paradigm for modeling temperature sensitivity of soil C pools and understanding of microbial enzyme dynamics.

  19. RoboDiff: combining a sample changer and goniometer for highly automated macromolecular crystallography experiments

    Science.gov (United States)

    Nurizzo, Didier; Bowler, Matthew W.; Caserotto, Hugo; Dobias, Fabien; Giraud, Thierry; Surr, John; Guichard, Nicolas; Papp, Gergely; Guijarro, Matias; Mueller-Dieckmann, Christoph; Flot, David; McSweeney, Sean; Cipriani, Florent; Theveneau, Pascal; Leonard, Gordon A.

    2016-01-01

    Automation of the mounting of cryocooled samples is now a feature of the majority of beamlines dedicated to macromolecular crystallography (MX). Robotic sample changers have been developed over many years, with the latest designs increasing capacity, reliability and speed. Here, the development of a new sample changer deployed at the ESRF beamline MASSIF-1 (ID30A-1), based on an industrial six-axis robot, is described. The device, named RoboDiff, includes a high-capacity dewar, acts as both a sample changer and a high-accuracy goniometer, and has been designed for completely unattended sample mounting and diffraction data collection. This aim has been achieved using a high level of diagnostics at all steps of the process from mounting and characterization to data collection. The RoboDiff has been in service on the fully automated endstation MASSIF-1 at the ESRF since September 2014 and, at the time of writing, has processed more than 20 000 samples completely automatically. PMID:27487827

  20. Diffraction cartography: applying microbeams to macromolecular crystallography sample evaluation and data collection.

    Science.gov (United States)

    Bowler, Matthew W; Guijarro, Matias; Petitdemange, Sebastien; Baker, Isabel; Svensson, Olof; Burghammer, Manfred; Mueller-Dieckmann, Christoph; Gordon, Elspeth J; Flot, David; McSweeney, Sean M; Leonard, Gordon A

    2010-08-01

    Crystals of biological macromolecules often exhibit considerable inter-crystal and intra-crystal variation in diffraction quality. This requires the evaluation of many samples prior to data collection, a practice that is already widespread in macromolecular crystallography. As structural biologists move towards tackling ever more ambitious projects, new automated methods of sample evaluation will become crucial to the success of many projects, as will the availability of synchrotron-based facilities optimized for high-throughput evaluation of the diffraction characteristics of samples. Here, two examples of the types of advanced sample evaluation that will be required are presented: searching within a sample-containing loop for microcrystals using an X-ray beam of 5 microm diameter and selecting the most ordered regions of relatively large crystals using X-ray beams of 5-50 microm in diameter. A graphical user interface developed to assist with these screening methods is also presented. For the case in which the diffraction quality of a relatively large crystal is probed using a microbeam, the usefulness and implications of mapping diffraction-quality heterogeneity (diffraction cartography) are discussed. The implementation of these techniques in the context of planned upgrades to the ESRF's structural biology beamlines is also presented.

  1. Effects of sound exposure on the growth and intracellular macromolecular synthesis of E. coli k-12.

    Science.gov (United States)

    Gu, Shaobin; Zhang, Yongzhu; Wu, Ying

    2016-01-01

    Microbes, as one of the primary producers of the biosphere, play an important role in ecosystems. Exploring the mechanism of adaptation and resistance of microbial population to various environmental factors has come into focus in the fields of modern microbial ecology and molecular ecology. However, facing the increasingly serious problem of acoustic pollution, very few efforts have been put forth into studying the relation of single cell organisms and sound field exposure. Herein, we studied the biological effects of sound exposure on the growth of E. coli K-12 with different acoustic parameters. The effects of sound exposure on the intracellular macromolecular synthesis and cellular morphology of E. coli K-12 were also analyzed and discussed. Experimental results indicated that E. coli K-12 exposed to sound waves owned a higher biomass and a faster specific growth rate compared to the control group. Also, the average length of E. coli K-12 cells increased more than 27.26%. The maximum biomass and maximum specific growth rate of the stimulation group by 8000 Hz, 80dB sound wave was about 1.7 times and 2.5 times that of the control group, respectively. Moreover, it was observed that E. coli K-12 can respond rapidly to sound stress at both the transcriptional and posttranscriptional levels by promoting the synthesis of intracellular RNA and total protein. Some potential mechanisms may be involved in the responses of bacterial cells to sound stress. PMID:27077011

  2. A test of macromolecular crystallization in microgravity: large well ordered insulin crystals.

    Science.gov (United States)

    Borgstahl, G E; Vahedi-Faridi, A; Lovelace, J; Bellamy, H D; Snell, E H

    2001-08-01

    Crystals of insulin grown in microgravity on Space Shuttle Mission STS-95 were extremely well ordered and unusually large (many >2 mm). The physical characteristics of six microgravity and six earth-grown crystals were examined by X-ray analysis employing superfine phi slicing and unfocused synchrotron radiation. This experimental setup allowed hundreds of reflections to be precisely examined from each crystal in a short period of time. The microgravity crystals were on average 34 times larger, had sevenfold lower mosaicity, had 54-fold higher reflection peak heights and diffracted to significantly higher resolution than their earth-grown counterparts. A single mosaic domain model could account for the observed reflection profiles in microgravity crystals, whereas data from earth crystals required a model with multiple mosaic domains. This statistically significant and unbiased characterization indicates that the microgravity environment was useful for the improvement of crystal growth and the resultant diffraction quality in insulin crystals and may be similarly useful for macromolecular crystals in general.

  3. Competitive interactions of ligands and macromolecular crowders with maltose binding protein.

    Directory of Open Access Journals (Sweden)

    Andrew C Miklos

    Full Text Available Cellular signaling involves a cascade of recognition events occurring in a complex environment with high concentrations of proteins, polysaccharides, and other macromolecules. The influence of macromolecular crowders on protein binding affinity through hard-core repulsion is well studied, and possible contributions of protein-crowder soft attraction have been implicated recently. Here we present direct evidence for weak association of maltose binding protein (MBP with a polysaccharide crowder Ficoll, and that this association effectively competes with the binding of the natural ligand, maltose. Titration data over wide ranges of maltose and Ficoll concentrations fit well with a three-state competitive binding model. Broadening of MBP (1H-(15N TROSY spectra by the addition of Ficoll indicates weak protein-crowder association, and subsequent recovery of sharp NMR peaks upon addition of maltose indicates that the interactions of the crowder and the ligand with MBP are competitive. We hypothesize that, in the Escherichia coli periplasm, the competitive interactions of polysaccharides and maltose with MBP could allow MBP to shuttle between the peptidoglycan attached to the outer membrane and the ATP-binding cassette transporter in the inner membrane.

  4. About Small Streams and Shiny Rocks: Macromolecular Crystal Growth in Microfluidics

    Science.gov (United States)

    vanderWoerd, Mark; Ferree, Darren; Spearing, Scott; Monaco, Lisa; Molho, Josh; Spaid, Michael; Brasseur, Mike; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    We are developing a novel technique with which we have grown diffraction quality protein crystals in very small volumes, utilizing chip-based, microfluidic ("LabChip") technology. With this technology volumes smaller than achievable with any laboratory pipette can be dispensed with high accuracy. We have performed a feasibility study in which we crystallized several proteins with the aid of a LabChip device. The protein crystals are of excellent quality as shown by X-ray diffraction. The advantages of this new technology include improved accuracy of dispensing for small volumes, complete mixing of solution constituents without bubble formation, highly repeatable recipe and growth condition replication, and easy automation of the method. We have designed a first LabChip device specifically for protein crystallization in batch mode and can reliably dispense and mix from a range of solution constituents. We are currently testing this design. Upon completion additional crystallization techniques, such as vapor diffusion and liquid-liquid diffusion will be accommodated. Macromolecular crystallization using microfluidic technology is envisioned as a fully automated system, which will use the 'tele-science' concept of remote operation and will be developed into a research facility aboard the International Space Station.

  5. RoboDiff: combining a sample changer and goniometer for highly automated macromolecular crystallography experiments.

    Science.gov (United States)

    Nurizzo, Didier; Bowler, Matthew W; Caserotto, Hugo; Dobias, Fabien; Giraud, Thierry; Surr, John; Guichard, Nicolas; Papp, Gergely; Guijarro, Matias; Mueller-Dieckmann, Christoph; Flot, David; McSweeney, Sean; Cipriani, Florent; Theveneau, Pascal; Leonard, Gordon A

    2016-08-01

    Automation of the mounting of cryocooled samples is now a feature of the majority of beamlines dedicated to macromolecular crystallography (MX). Robotic sample changers have been developed over many years, with the latest designs increasing capacity, reliability and speed. Here, the development of a new sample changer deployed at the ESRF beamline MASSIF-1 (ID30A-1), based on an industrial six-axis robot, is described. The device, named RoboDiff, includes a high-capacity dewar, acts as both a sample changer and a high-accuracy goniometer, and has been designed for completely unattended sample mounting and diffraction data collection. This aim has been achieved using a high level of diagnostics at all steps of the process from mounting and characterization to data collection. The RoboDiff has been in service on the fully automated endstation MASSIF-1 at the ESRF since September 2014 and, at the time of writing, has processed more than 20 000 samples completely automatically. PMID:27487827

  6. A graph theoretical approach for assessing bio-macromolecular complex structural stability.

    Science.gov (United States)

    Del Carpio, Carlos Adriel; Iulian Florea, Mihai; Suzuki, Ai; Tsuboi, Hideyuki; Hatakeyama, Nozomu; Endou, Akira; Takaba, Hiromitsu; Ichiishi, Eiichiro; Miyamoto, Akira

    2009-11-01

    Fast and proper assessment of bio macro-molecular complex structural rigidity as a measure of structural stability can be useful in systematic studies to predict molecular function, and can also enable the design of rapid scoring functions to rank automatically generated bio-molecular complexes. Based on the graph theoretical approach of Jacobs et al. [Jacobs DJ, Rader AJ, Kuhn LA, Thorpe MF (2001) Protein flexibility predictions using graph theory. Proteins: Struct Funct Genet 44:150-165] for expressing molecular flexibility, we propose a new scheme to analyze the structural stability of bio-molecular complexes. This analysis is performed in terms of the identification in interacting subunits of clusters of flappy amino acids (those constituting regions of potential internal motion) that undergo an increase in rigidity at complex formation. Gains in structural rigidity of the interacting subunits upon bio-molecular complex formation can be evaluated by expansion of the network of intra-molecular inter-atomic interactions to include inter-molecular inter-atomic interaction terms. We propose two indices for quantifying this change: one local, which can express localized (at the amino acid level) structural rigidity, the other global to express overall structural stability for the complex. The new system is validated with a series of protein complex structures reported in the protein data bank. Finally, the indices are used as scoring coefficients to rank automatically generated protein complex decoys.

  7. SPring-8 BL41XU, a high-flux macromolecular crystallography beamline

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Kazuya [SPring-8/JASRI, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Shimizu, Nobutaka [SPring-8/JASRI, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); KEK-PF, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Okumura, Hideo; Mizuno, Nobuhiro; Baba, Seiki [SPring-8/JASRI, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Hirata, Kunio [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Takeuchi, Tomoyuki; Yamazaki, Hiroshi; Senba, Yasunori; Ohashi, Haruhiko [SPring-8/JASRI, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Yamamoto, Masaki [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Kumasaka, Takashi, E-mail: kumasaka@spring8.or.jp [SPring-8/JASRI, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)

    2013-11-01

    SPring-8 BL41XU provides a high-flux X-ray beam of size 10–50 µm, and enables high-quality diffraction data to be obtained from various types of protein crystals. Details of this beamline and an upgrade project are described. SPring-8 BL41XU is a high-flux macromolecular crystallography beamline using an in-vacuum undulator as a light source. The X-rays are monochromated by a liquid-nitrogen-cooling Si double-crystal monochromator, and focused by Kirkpatrick–Baez mirror optics. The focused beam size at the sample is 80 µm (H) × 22 µm (V) with a photon flux of 1.1 × 10{sup 13} photons s{sup −1}. A pinhole aperture is used to collimate the beam in the range 10–50 µm. This high-flux beam with variable size provides opportunities not only for micro-crystallography but also for data collection effectively making use of crystal volume. The beamline also provides high-energy X-rays covering 20.6–35.4 keV which allows ultra-high-resolution data to be obtained and anomalous diffraction using the K-edge of Xe and I. Upgrade of BL41XU for more rapid and accurate data collection is proceeding. Here, details of BL41XU are given and an outline of the upgrade project is documented.

  8. SCIENTIFIC PRINCIPLES FOR MODIFICATION OF WATER-SOLUBLE POLYMERS. FORMATION OF MACROMOLECULAR COMPLEXES

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The study of nanosecond dynamics of macromolecules with the luminescent methods make it possible to investigate the formation and functioning of polymeric complexes, polymeric conjugates and macromolecular metal complexes, which are widely used for solving many practical tasks. The nanosecond dynamics of macromolecules are a highly sensitive indicator of interpolymer complexes (IPC) formation. It enables us to solve the problems of studying IPC formation and stability and to investigate the interpolymer reactions of exchange and substitution. The investigation of changes in the rotational mobility of globular protein molecules as a whole makes it possible to determine the complex composition and its stability, and to control the course of polymer-protein conjugate formstion reaction. The nanosecond dynamics of polymers interacting with surfacants' ions (S)are the sensitive indicator of the S-polymer complex formation. A method for determining the equilibrium constants of the S-polymer complex formation was developed on the basis of the study of polymer chains mobility. It is established that nanosecond dynamics influences the course of chemical reactions in polymer chains. Moreover, the marked effect of the nanosecond dynamics is also revealed in the study of photophysical processes (the formation of excimers and energy migration of electron excitation) in polymers with photoactive groups. It was found that the efficiency of both processes increases with increasing the mobility of side chains, the carriers of photoactive groups.

  9. Proteinase K activity determination with β-galactosidase as sensitive macromolecular substrate.

    Science.gov (United States)

    Ghéczy, Nicolas; Küchler, Andreas; Walde, Peter

    2016-11-15

    Proteinase K from Engyodontium album (proK) is a relatively unspecific serine endopeptidase which is known to attack proteins yet in their native states. If the attacked protein is an enzyme, even a partial hydrolysis by proK may lead to an inactivation of the enzyme, which can be monitored by measuring the loss of catalytic activity of the attacked enzyme. E. coli β-galactosidase (β-Gal) was used in this work as such enzyme. It was found to be a convenient and sensitive macromolecular model substrate for comparing the "native protein-attacking ability" of free and immobilized proK at pH = 7.0 and 23 °C. The β-Gal activity was measured spectrophotometrically with o-nitrophenyl-β-galactopyranoside. Reproducible proK determinations were possible for as little as 4.3 ng proK by using a proK analyte solution of 10 nM. Compared to free proK, immobilized proK was much less efficient in inactivating β-Gal, most likely due to a decreased mobility of immobilized proK and a restricted accessibility of β-Gal to the active site of proK. Worth noting is, that under conditions at which β-Gal was completely inactivated by proK, the activity of hen egg lysozyme, horseradish peroxidase, or Aspergillus sp. glucose oxidase remained unaltered. PMID:27594349

  10. Proteinase K activity determination with β-galactosidase as sensitive macromolecular substrate.

    Science.gov (United States)

    Ghéczy, Nicolas; Küchler, Andreas; Walde, Peter

    2016-11-15

    Proteinase K from Engyodontium album (proK) is a relatively unspecific serine endopeptidase which is known to attack proteins yet in their native states. If the attacked protein is an enzyme, even a partial hydrolysis by proK may lead to an inactivation of the enzyme, which can be monitored by measuring the loss of catalytic activity of the attacked enzyme. E. coli β-galactosidase (β-Gal) was used in this work as such enzyme. It was found to be a convenient and sensitive macromolecular model substrate for comparing the "native protein-attacking ability" of free and immobilized proK at pH = 7.0 and 23 °C. The β-Gal activity was measured spectrophotometrically with o-nitrophenyl-β-galactopyranoside. Reproducible proK determinations were possible for as little as 4.3 ng proK by using a proK analyte solution of 10 nM. Compared to free proK, immobilized proK was much less efficient in inactivating β-Gal, most likely due to a decreased mobility of immobilized proK and a restricted accessibility of β-Gal to the active site of proK. Worth noting is, that under conditions at which β-Gal was completely inactivated by proK, the activity of hen egg lysozyme, horseradish peroxidase, or Aspergillus sp. glucose oxidase remained unaltered.

  11. Native gel analysis of macromolecular protein complexes in cultured mammalian cells.

    Science.gov (United States)

    Munawar, Nayla; Olivero, Giorgio; Jerman, Emilia; Doyle, Benjamin; Streubel, Gundula; Wynne, Kieran; Bracken, Adrian; Cagney, Gerard

    2015-11-01

    Native gel electrophoresis enables separation of cellular proteins in their non-denatured state. In experiments aimed at analysing proteins in higher order or multimeric assemblies (i.e. protein complexes) it offers some advantages over rival approaches, particularly as an interface technology with mass spectrometry. Here we separated fractions from HEK293 cells by native electrophoresis in order to survey protein complexes in the cytoplasmic, nuclear and chromatin environments, finding 689 proteins distributed among 217 previously described complexes. As expected, different fractions contained distinct combinations of macromolecular complexes, with subunits of the same complex tending to co-migrate. Exceptions to this observation could often be explained by the presence of subunits shared among different complexes. We investigated one identified complex, the Polycomb Repressor Complex 2 (PRC2), in more detail following affinity purification of the EZH2 subunit. This approach resulted in the identification of all previously reported members of PRC2. Overall, this work demonstrates that the use of native gel electrophoresis as an upstream separating step is an effective approach for analysis of the components and cellular distribution of protein complexes. PMID:26223664

  12. RoboDiff: combining a sample changer and goniometer for highly automated macromolecular crystallography experiments.

    Science.gov (United States)

    Nurizzo, Didier; Bowler, Matthew W; Caserotto, Hugo; Dobias, Fabien; Giraud, Thierry; Surr, John; Guichard, Nicolas; Papp, Gergely; Guijarro, Matias; Mueller-Dieckmann, Christoph; Flot, David; McSweeney, Sean; Cipriani, Florent; Theveneau, Pascal; Leonard, Gordon A

    2016-08-01

    Automation of the mounting of cryocooled samples is now a feature of the majority of beamlines dedicated to macromolecular crystallography (MX). Robotic sample changers have been developed over many years, with the latest designs increasing capacity, reliability and speed. Here, the development of a new sample changer deployed at the ESRF beamline MASSIF-1 (ID30A-1), based on an industrial six-axis robot, is described. The device, named RoboDiff, includes a high-capacity dewar, acts as both a sample changer and a high-accuracy goniometer, and has been designed for completely unattended sample mounting and diffraction data collection. This aim has been achieved using a high level of diagnostics at all steps of the process from mounting and characterization to data collection. The RoboDiff has been in service on the fully automated endstation MASSIF-1 at the ESRF since September 2014 and, at the time of writing, has processed more than 20 000 samples completely automatically.

  13. Experimental determination of methane dissolution from simulated subsurface oil leakages

    Science.gov (United States)

    Sauthoff, W.; Peltzer, E. T.; Walz, P. M.; Brewer, P. G.

    2013-12-01

    Subsurface oil leakages and increased offshore drilling efforts have raised concern over the fate of hydrocarbon mixtures of oil and gas in ocean environments. Recent wellhead and pipeline failures in the Gulf of Mexico are extreme examples of this problem. Understanding the mechanism and rate of vertical transport of hydrocarbon chemical species is necessary to predict the environmental impact of subsurface leakages. In a series of controlled experiments, we carried out a deep-sea field experiment in Monterey Canyon to investigate the behavior of a gas-saturated liquid hydrocarbon mass rising from the seafloor. Aboard the R/V Rachel Carson, we used the ROV Ventana to transport a laboratory prepared volume of decane (C10H22) saturated with methane gas (CH4) to mimic a subsurface seafloor discharge. We released the oil and gas mixture into a vertically oriented open bottom glass tube followed by methane loss rate measurements both at discrete depths, and during rapid, continuous vehicle ascent from 800 to 100 m water depth to monitor changes in dissolution and bubble nucleation. Using laser Raman techniques and HD video we quantified the chemical state of the hydrocarbon fluid, including rate of methane gas dissolution. The primary methane Raman peak was readily observable within the decane C-H stretching complex. Variation in the amount of gas dissolved in the oil greatly influences oil plume density and in turn oil plume vertical rise rate. Our results show that the rise rate of the hydrocarbon mass significantly exceeds the rate at which the excess methane was lost by dissolution. This result implies that vertical transport of methane in the saturated hydrocarbon liquid phase can greatly exceed a gas bubble plume ascending the water column from a seafloor source. These results and observations may be applicable to improved understanding of the composition, distribution, and environmental fate of leaked hydrocarbon mixtures and inform remediation efforts.

  14. Mind the gap - tip leakage vortex in axial turbines

    International Nuclear Information System (INIS)

    The tendency of designing large Kaplan turbines with a continuous increase of output power is bringing to the front the cavitation erosion issue. Due to the flow in the gap between the runner and the discharge ring, axial turbine blades may develop the so called tip leakage vortex (TLV) cavitation with negative consequences. Such vortices may interact strongly with the wake of guide vanes leading to their multiple collapses and rebounds. If the vortex trajectory remains close to the blade tip, these collapses may lead to severe erosion. One is still unable today to predict its occurrence and development in axial turbines with acceptable accuracy. Numerical flow simulations as well as the actual scale-up rules from small to large scales are unreliable. The present work addresses this problematic in a simplified case study representing TLV cavitation to better understand its sensitivity to the gap width. A Naca0009 hydrofoil is used as a generic blade in the test section of EPFL cavitation tunnel. A sliding mounting support allowing an adjustable gap between the blade tip and wall was manufactured. The vortex trajectory is visualized with a high speed camera and appropriate lighting. The three dimensional velocity field induced by the TLV is investigated using stereo particle image velocimetry. We have taken into account the vortex wandering in the image processing to obtain accurate measurements of the vortex properties. The measurements were performed in three planes located downstream of the hydrofoil for different values of the flow velocity, the incidence angle and the gap width. The results clearly reveal a strong influence of the gap width on both trajectory and intensity of the tip leakage vortex

  15. SETI via Leakage from Light Sails in Exoplanetary Systems

    Science.gov (United States)

    Guillochon, James; Loeb, Abraham

    2015-10-01

    The primary challenge of rocket propulsion is the burden of needing to accelerate the spacecraft’s own fuel, resulting in only a logarithmic gain in maximum speed as propellant is added to the spacecraft. Light sails offer an attractive alternative in which fuel is not carried by the spacecraft, with acceleration being provided by an external source of light. By artificially illuminating the spacecraft with beamed radiation, speeds are only limited by the area of the sail, heat resistance of its material, and power use of the accelerating apparatus. In this paper, we show that leakage from a light sail propulsion apparatus in operation around a solar system analogue would be detectable. To demonstrate this, we model the launch and arrival of a microwave beam-driven light sail constructed for transit between planets in orbit around a single star, and find an optimal beam frequency on the order of tens of GHz. Leakage from these beams yields transients with flux densities of Jy and durations of tens of seconds at 100 pc. Because most travel within a planetary system would be conducted between the habitable worlds within that system, multiply transiting exoplanetary systems offer the greatest chance of detection, especially when the planets are in projected conjunction as viewed from Earth. If interplanetary travel via beam-driven light sails is commonly employed in our galaxy, this activity could be revealed by radio follow-up of nearby transiting exoplanetary systems. The expected signal properties define a new strategy in the search for extraterrestrial intelligence (SETI).

  16. Mind the gap - tip leakage vortex in axial turbines

    Science.gov (United States)

    Dreyer, M.; Decaix, J.; Münch-Alligné, C.; Farhat, M.

    2014-03-01

    The tendency of designing large Kaplan turbines with a continuous increase of output power is bringing to the front the cavitation erosion issue. Due to the flow in the gap between the runner and the discharge ring, axial turbine blades may develop the so called tip leakage vortex (TLV) cavitation with negative consequences. Such vortices may interact strongly with the wake of guide vanes leading to their multiple collapses and rebounds. If the vortex trajectory remains close to the blade tip, these collapses may lead to severe erosion. One is still unable today to predict its occurrence and development in axial turbines with acceptable accuracy. Numerical flow simulations as well as the actual scale-up rules from small to large scales are unreliable. The present work addresses this problematic in a simplified case study representing TLV cavitation to better understand its sensitivity to the gap width. A Naca0009 hydrofoil is used as a generic blade in the test section of EPFL cavitation tunnel. A sliding mounting support allowing an adjustable gap between the blade tip and wall was manufactured. The vortex trajectory is visualized with a high speed camera and appropriate lighting. The three dimensional velocity field induced by the TLV is investigated using stereo particle image velocimetry. We have taken into account the vortex wandering in the image processing to obtain accurate measurements of the vortex properties. The measurements were performed in three planes located downstream of the hydrofoil for different values of the flow velocity, the incidence angle and the gap width. The results clearly reveal a strong influence of the gap width on both trajectory and intensity of the tip leakage vortex.

  17. MANAGEMENT OF CEREBROSPINAL FLUID LEAKAGE FOLLOWING CERVICAL SPINE SURGERY

    Institute of Scientific and Technical Information of China (English)

    Ye Tian; Ke-yi Yu; Yi-peng Wang; Jun Qian; Gui-xing Qiu

    2008-01-01

    Objective To investigate the management and outcome of cerebrospinal fluid leakage (CSFL) after cervical surgery. Methods Medical records of 642 patients who underwent cervical surgery between December 1999 and December 2005 at our hospital were retrospectively reviewed. Five patients complicated by CSFL after surgery were enrolled, of which 4 cases were complicated after ossified posterior longitudinal ligament or posterior vertebral osteophyte resection directly injuring the dura, and 1 case after posterior cervical double-door laminoplasty with out observed dural injury during surgery. Of the 5 CSFL cases, 4 cases occurred at 1-3 days after operation and 1 case at 9 days after operation. All 5 postoperative CSFL cases were treated through wound drainage removal, wound sutures, prophylactic antibiotics, and continuous subarachnoid drainage in the elevated head position.Results All 5 CSFL cases experienced leakage cessation within 1-3 days and wound healing within 4-8 days, and subarachnoid drainage lasted 11-16 days with an average volume of 320 mL (range, 150-410 mL). Four cases experienced headache, nausea and vomiting, 1 case suffered from somnolence and hyponatremia, and symptoms subsided after symptomatic treatment and intravenous fluid administration. All patients were followed up for an average of 32 months (range, 22-50 months). No occurrence of cerebrospinal fluid cyst or wound infection was observed. CSFL produced no significant negative effects upon neuromuscular function recovery.Conclusion Continuous subarachnoid cavity drainage in combination with elevated head position is a simple and safe non-surgical method in treatment of CSFL following cervical surgery.

  18. SETI VIA LEAKAGE FROM LIGHT SAILS IN EXOPLANETARY SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Guillochon, James; Loeb, Abraham, E-mail: jguillochon@cfa.harvard.edu, E-mail: aloeb@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, The Institute for Theory and Computation, 60 Garden Street, Cambridge, MA 02138 (United States)

    2015-10-01

    The primary challenge of rocket propulsion is the burden of needing to accelerate the spacecraft’s own fuel, resulting in only a logarithmic gain in maximum speed as propellant is added to the spacecraft. Light sails offer an attractive alternative in which fuel is not carried by the spacecraft, with acceleration being provided by an external source of light. By artificially illuminating the spacecraft with beamed radiation, speeds are only limited by the area of the sail, heat resistance of its material, and power use of the accelerating apparatus. In this paper, we show that leakage from a light sail propulsion apparatus in operation around a solar system analogue would be detectable. To demonstrate this, we model the launch and arrival of a microwave beam-driven light sail constructed for transit between planets in orbit around a single star, and find an optimal beam frequency on the order of tens of GHz. Leakage from these beams yields transients with flux densities of Jy and durations of tens of seconds at 100 pc. Because most travel within a planetary system would be conducted between the habitable worlds within that system, multiply transiting exoplanetary systems offer the greatest chance of detection, especially when the planets are in projected conjunction as viewed from Earth. If interplanetary travel via beam-driven light sails is commonly employed in our galaxy, this activity could be revealed by radio follow-up of nearby transiting exoplanetary systems. The expected signal properties define a new strategy in the search for extraterrestrial intelligence (SETI)

  19. Regulatory analysis for the resolution of generic issue C---8, main steam isolation valve leakage and LCS [leakage control system] failure

    International Nuclear Information System (INIS)

    Generic Issue C-8 deals with staff concerns about public risk because of the incidence of leak test failures reported for main steam isolation valves (MSIVs) at boiling water reactors and the limitations of the leakage control systems (LCSs) for mitigating the consequences of leakage from these valves. If the MSIV leakage is greatly in excess of the allowable value in the technical specifications, the LCS would be unavailable because of design limitations. The issue was initiated in 1983 to assess (1) the causes of MSIV leakage failures, (2) the effectiveness of the LCS and alternative mitigation paths, and (3) the need for additional regulatory action to reduce public risk. This report presents the regulatory analysis for Generic Issue C-8 and concludes that no new regulatory requirements are warranted

  20. A novel micropump with fixed-geometry valves and low leakage flow

    Science.gov (United States)

    Hwang, Il-Han; An, Jae-Yong; Ko, Kwang-Hee; Shin, Sang-Mo; Lee, Jong-Hyun

    2007-08-01

    A novel micropump with fixed-geometry valves was designed and tested with a leakage barrier to reduce leakage flow. Conventional micropumps with fixed-geometry valves have achieved net positive fluid flow from different fluid resistances in diffuser/nozzle channels. However, those micropumps are susceptible to leakage flow even at low pressure differences between the inlet and the outlet because the channels remain normally open state when the pumps are not in operation. Therefore, a leakage barrier in the chamber was designed to reduce leakage flow without interfering with the net positive fluid flow of the diffuser/nozzle channels. The diffuser/nozzle channels, the chamber and the leakage barrier were fabricated on the silicon substrate by KOH etching and the silicon substrate was anodically bonded with a Pyrex glass plate. A PZT disk was bonded on the glass plate by epoxy and was actuated to oscillate the glass diaphragm for flow generation. When the micropump is not operating, the leakage barrier removes most of the gap between the glass plate and the bottom of the chamber. It was experimentally confirmed that the leakage barrier reduced the leakage flow by 96% compared to the case of no leakage barrier at a pressure difference of -400 Pa. Moreover, by applying the holding dc voltage to the PZT disk, a smaller gap can be obtained reducing the leakage flow further down to 0.043 µL min-1 at a holding dc voltage of 100 V. The maximum flow rate was 3.9 µL min-1 at a peak-to-peak driving voltage of 150 V at 20 Hz with a maximum back pressure of around 800 Pa. The approximate device size was 18 × 25 mm2.

  1. Domino logic designs for high-performance and leakage-tolerant applications

    DEFF Research Database (Denmark)

    Moradi, Farshad; Vu Cao, Tuan; Vatajelu, Elena Ioana;

    2013-01-01

    Robustness of high fan-in domino circuits is degraded by technology scaling due to exponential increase in leakage. In this paper, we propose several domino logic circuit techniques to improve the robustness and performance along with leakage power. Lower total power consumption is achieved...

  2. Uncertainty Analysis for Assessing Leakage Through Water Tunnels: A Case from Nepal Himalaya

    Science.gov (United States)

    Panthi, Krishna Kanta; Nilsen, Bjørn

    2010-09-01

    Water leakage problems in unlined or shotcrete lined water tunnels are not new issues. In many occasions severe water leakage problems have been faced that not only have reduced the stability of the rock mass, but also have caused valuable water to be lost from it, causing safety risk as well as huge economic loss to the projects. Hence, making tunnels water tight plays an important role in improving stability and safety of underground excavations. The real challenge is however accurate prediction and quantification of possible water leakage, so that cost consequences can be incorporated during planning of a water conveying tunnel project. The main purposes of this paper are to analyze extensive data on leakage test carried out through exploratory drillhole used to define the need for pre-injection grouting of Khimti headrace tunnel and to carry out probabilistic approach of uncertainty analysis based on relationship established between leakage, hydrostatic head and selected Q-value parameters. The authors believe that the new approach regarding uncertainty analysis of leakage presented in this paper will improve the understanding of leakage characteristics of the rock mass, and hope this will lead to a better understanding concerning quantification of possible water leakage from unlined and shotcrete lined water tunnels.

  3. Quantification of leakage from large unilamellar lipid vesicles by fluorescence correlation spectroscopy

    DEFF Research Database (Denmark)

    Kristensen, Kasper; Henriksen, Jonas Rosager; Andresen, Thomas Lars

    2014-01-01

    that mastoparan X forms transient transmembrane pores in POPC/POPG (3:1) vesicles, resulting in size-dependent leakage of molecules from the vesicles. We conclude the paper by discussing some of the advantages and limitations of FCS as compared to other existing methods to measure leakage from large unilamellar...

  4. Estimating the environmental and resource costs of leakage in water distribution systems: A shadow price approach.

    Science.gov (United States)

    Molinos-Senante, María; Mocholí-Arce, Manuel; Sala-Garrido, Ramon

    2016-10-15

    Water scarcity is one of the main problems faced by many regions in the XXIst century. In this context, the need to reduce leakages from water distribution systems has gained almost universal acceptance. The concept of sustainable economic level of leakage (SELL) has been proposed to internalize the environmental and resource costs within economic level of leakage calculations. However, because these costs are not set by the market, they have not often been calculated. In this paper, the directional-distance function was used to estimate the shadow price of leakages as a proxy of their environmental and resource costs. This is a pioneering approach to the economic valuation of leakage externalities. An empirical application was carried out for the main Chilean water companies. The estimated results indicated that for 2014, the average shadow price of leakages was approximately 32% of the price of the water delivered. Moreover, as a sensitivity analysis, the shadow prices of the leakages were calculated from the perspective of the water companies' managers and the regulator. The methodology and findings of this study are essential for supporting the decision process of reducing leakage, contributing to the improvement of economic, social and environmental efficiency and sustainability of urban water supplies. PMID:27289397

  5. Developments in Impeller/Seal Secondary Flow Path Modeling for Dynamic Force Coefficients and Leakage

    Science.gov (United States)

    Palazzolo, Alan; Bhattacharya, Avijit; Athavale, Mahesh; Venkataraman, Balaji; Ryan, Steve; Funston, Kerry

    1997-01-01

    This paper highlights bulk flow and CFD-based models prepared to calculate force and leakage properties for seals and shrouded impeller leakage paths. The bulk flow approach uses a Hir's based friction model and the CFD approach solves the Navier Stoke's (NS) equation with a finite whirl orbit or via analytical perturbation. The results show good agreement in most instances with available benchmarks.

  6. Hyperspectral indices for detecting changes in canopy reflectance as a result of underground natural gas leakage

    NARCIS (Netherlands)

    Noomen, M.F.; Smith, K.L.; Colls, J.J.; Steven, M.D.; Skidmore, A.K.; Meer, van der F.D.

    2008-01-01

    Natural gas leakage from underground pipelines is known to affect vegetation adversely, probably by displacement of the soil oxygen needed for respiration. This causes changes in plant and canopy reflectance, which may serve as indicators of gas leakage. In this study, a covariance analysis was perf

  7. Physical investigation into the significance of ground conditions on dynamic leakage behaviour

    OpenAIRE

    Fox, S.; Collins, R; Boxall, J

    2016-01-01

    Effective leakage models are crucial for leakage assessment and control strategies to improve the sustainability of vital water distribution, and other pipeline, infrastructure. This paper evaluates the interdependence of leak hydraulics, structural dynamics and soil hydraulics, particularly considering the significance of the soil conditions external to longitudinal slits in viscoelastic pipe. Initial numerical exploration and unique physical experimental results are presented ex...

  8. Blood-brain barrier leakage after status epilepticus in rapamycin-treated rats II: Potential mechanisms

    NARCIS (Netherlands)

    E.A. van Vliet; W.M. Otte; W.J. Wadman; E. Aronica; G. Kooij; H.E. de Vries; R.M. Dijkhuizen; J.A. Gorter

    2016-01-01

    OBJECTIVE: Blood-brain barrier (BBB) leakage may play a pro-epileptogenic role after status epilepticus. In the accompanying contrast-enhanced magnetic resonance imaging (CE-MRI) study we showed that the mammalian target of rapamycin (mTOR) inhibitor rapamycin reduced BBB leakage and seizure activit

  9. Blood-brain barrier leakage after status epilepticus in rapamycin-treated rats II : Potential mechanisms

    NARCIS (Netherlands)

    van Vliet, Erwin A; Otte, Wim M; Wadman, Wytse J; Aronica, Eleonora; Kooij, Gijs; de Vries, Helga E; Dijkhuizen, Rick M; Gorter, Jan A

    2016-01-01

    OBJECTIVE: Blood-brain barrier (BBB) leakage may play a pro-epileptogenic role after status epilepticus. In the accompanying contrast-enhanced magnetic resonance imaging (CE-MRI) study we showed that the mammalian target of rapamycin (mTOR) inhibitor rapamycin reduced BBB leakage and seizure activit

  10. The Dutch multicenter experience of the Endo-Sponge treatment for anastomotic leakage after colorectal surgery

    NARCIS (Netherlands)

    P.J. van Koperen; M.I. van Berge Henegouwen; C. Rosman; C.M. Bakker; P. Heres; J.F.M. Slors; W.A. Bemelman

    2009-01-01

    Anastomotic leakage is a feared complication following colorectal surgery and is associated with early and long-term morbidity and mortality. The presacral cavity as the result of leakage can be treated with an endo-sponge (B-Braun Medical). The aim of this study was to assess the effectiveness of e

  11. Leakage Characteristics of Dual-Cannula Fenestrated Tracheostomy Tubes during Positive Pressure Ventilation: A Bench Study

    Directory of Open Access Journals (Sweden)

    Thomas Berlet

    2016-01-01

    Full Text Available This study compared the leakage characteristics of different types of dual-cannula fenestrated tracheostomy tubes during positive pressure ventilation. Fenestrated Portex® Blue Line Ultra®, TRACOE® twist, or Rüsch® Traceofix® tracheostomy tubes equipped with nonfenestrated inner cannulas were tested in a tracheostomy-lung simulator. Transfenestration pressures and transfenestration leakage rates were measured during positive pressure ventilation. The impact of different ventilation modes, airway pressures, temperatures, and simulated static lung compliance settings on leakage characteristics was assessed. We observed substantial differences in transfenestration pressures and transfenestration leakage rates. The leakage rates of the best performing tubes were <3.5% of the delivered minute volume. At body temperature, the leakage rates of these tracheostomy tubes were <1%. The tracheal tube design was the main factor that determined the leakage characteristics. Careful tracheostomy tube selection permits the use of fenestrated tracheostomy tubes in patients receiving positive pressure ventilation immediately after stoma formation and minimises the risk of complications caused by transfenestration gas leakage, for example, subcutaneous emphysema.

  12. Leakage Characteristics of Dual-Cannula Fenestrated Tracheostomy Tubes during Positive Pressure Ventilation: A Bench Study.

    Science.gov (United States)

    Berlet, Thomas; Marchon, Mathias

    2016-01-01

    This study compared the leakage characteristics of different types of dual-cannula fenestrated tracheostomy tubes during positive pressure ventilation. Fenestrated Portex® Blue Line Ultra®, TRACOE® twist, or Rüsch® Traceofix® tracheostomy tubes equipped with nonfenestrated inner cannulas were tested in a tracheostomy-lung simulator. Transfenestration pressures and transfenestration leakage rates were measured during positive pressure ventilation. The impact of different ventilation modes, airway pressures, temperatures, and simulated static lung compliance settings on leakage characteristics was assessed. We observed substantial differences in transfenestration pressures and transfenestration leakage rates. The leakage rates of the best performing tubes were <3.5% of the delivered minute volume. At body temperature, the leakage rates of these tracheostomy tubes were <1%. The tracheal tube design was the main factor that determined the leakage characteristics. Careful tracheostomy tube selection permits the use of fenestrated tracheostomy tubes in patients receiving positive pressure ventilation immediately after stoma formation and minimises the risk of complications caused by transfenestration gas leakage, for example, subcutaneous emphysema.

  13. Oxygen-tension measurements - The first step towards prevention and early detection of anastomotic leakage

    NARCIS (Netherlands)

    Tanase, D.; French, P.J.; Komen, N.; Kleinrensink, G.J.; Jeekel, J.; Lange, J.F.; Draaijer, A.

    2007-01-01

    Many patients still die every year as a result of anastomotic leakage after surgery. The medical world needs an objective aid to detect leakage during surgery and during the critical recovery period. We propose a miniature measurement system to detect adequate tissue oxygenation pre- and postoperati

  14. Polarization leakage in epoch of reionization windows -- II. Primary beam model and direction dependent calibration

    CERN Document Server

    Asad, K M B; Jelić, V; Ghosh, A; Brentjens, M A; de Bruyn, A G; Ciardi, B; Iliev, I T; Mevius, M; Pandey, V N; Yatawatta, S; Zaroubi, S

    2016-01-01

    Leakage of diffuse polarized emission into Stokes I caused by the polarized primary beam of the instrument might mimic the spectral structure of the 21-cm signal coming from the epoch of reionization (EoR) making their separation difficult. Therefore, understanding polarimetric performance of the antenna is crucial for a successful detection of the EoR signal. Here, we have calculated the accuracy of the nominal model beam of LOFAR in predicting the leakage from Stokes I to Q, U by comparing them with the corresponding leakage of compact sources actually observed in the 3C295 field. We have found that the model beam has errors of less than or equal to 10% on the predicted levels of leakage of ~1%, i. e. if the leakage is taken out perfectly using this model the leakage will reduce to $10^{-3}$ of the Stokes I flux. If similar levels of accuracy can be obtained in removing leakage from Stokes Q, U to I, we can say, based on the results of our previous paper, that the removal of this leakage using this beam mod...

  15. Neutron leakage from Pb and Bc spherical shells with 14 MeV central neutron source

    International Nuclear Information System (INIS)

    Results of measuring neutron leakage from spherical shells of different thickness, made of Pb and Be with a point neutron source in the sphere centrum are presented. The experiment results are compared to calculations according to different programs using data of various nuclear data libraies. The comparison has shown that all the calculations understate the neutron leakage from Pb assmebly. 9 refs.; 2 tabs

  16. Leakage Current Optimization Techniques During Test Based on Don't Care Bits Assignment

    Institute of Scientific and Technical Information of China (English)

    Wei Wang; Yu Hu; Yin-He Han; Xiao-Wei Li; You-Sheng Zhang

    2007-01-01

    It is a well-known fact that test power consumption may exceed that during functional operation. Leakage power dissipation caused by leakage current in Complementary Metal-Oxide-Semiconductor (CMOS) circuits during test has become a significant part of the total power dissipation. Hence, it is important to reduce leakage power to prolong battery life in portable systems which employ periodic self-test, to increase test reliability and to reduce test cost. This paper analyzes leakage current and presents a kind of leakage current simulator based on the transistor stacking effect.Using it, we propose techniques based on don't care bits (denoted by Xs) in test vectors to optimize leakage current in integrated circuit (IC) test by genetic algorithm. The techniques identify a set of don't care inputs in given test vectors and reassign specified logic values to the X inputs by the genetic algorithm to get minimum leakage vector (MLV).Experimental results indicate that the techniques can effectually optimize leakage current of combinational circuits and sequential circuits during test while maintaining high fault coverage.

  17. Estimating the environmental and resource costs of leakage in water distribution systems: A shadow price approach.

    Science.gov (United States)

    Molinos-Senante, María; Mocholí-Arce, Manuel; Sala-Garrido, Ramon

    2016-10-15

    Water scarcity is one of the main problems faced by many regions in the XXIst century. In this context, the need to reduce leakages from water distribution systems has gained almost universal acceptance. The concept of sustainable economic level of leakage (SELL) has been proposed to internalize the environmental and resource costs within economic level of leakage calculations. However, because these costs are not set by the market, they have not often been calculated. In this paper, the directional-distance function was used to estimate the shadow price of leakages as a proxy of their environmental and resource costs. This is a pioneering approach to the economic valuation of leakage externalities. An empirical application was carried out for the main Chilean water companies. The estimated results indicated that for 2014, the average shadow price of leakages was approximately 32% of the price of the water delivered. Moreover, as a sensitivity analysis, the shadow prices of the leakages were calculated from the perspective of the water companies' managers and the regulator. The methodology and findings of this study are essential for supporting the decision process of reducing leakage, contributing to the improvement of economic, social and environmental efficiency and sustainability of urban water supplies.

  18. A two-dimensional simulation of plasma leakage due to dengue infection

    Science.gov (United States)

    Nuraini, N.; Windarto, Jayanti, Swarna; Soewono, Edy

    2014-03-01

    Dengue Hemorrhagic Fever (DHF) is a disease caused by Dengue virus infection. One major characteristic in a patient with DHF is the occurrence of plasma leakage. Plasma leakage is a consequence of the immune system mechanism which activates cytokine. As a result, permeability of vascular will increase. Another characteristic in a DHF patient is hypoalbuminea (decreasing of albumin concentration). Plasma leakage can be modelled by constructing mathematical model of albumin concentration in plasma blood due to increasing of cytokine. In this paper, decreasing of albumin concentration in blood plasma is modelled using diffusion equation. In addition, two-dimensional numerical simulations of albumin concentration are also presented. From the simulation, it is found that the greater leakage rate or the wider leakage area, the greater decreasing albumin concentration will be. Furthermore, when time t increases, the albumin concentration decreases to zero.

  19. Study on leakage flow characteristics of radial inflow turbines at rotor tip clearance

    Institute of Scientific and Technical Information of China (English)

    DENG QingHua; NIU JiuFang; FENG ZhenPing

    2008-01-01

    Tip clearance leakage flow in a radial inflow turbine rotor for microturbines under the stage environment is investigated using a three-dimensional viscous flow simulation. The results indicate that the scraping flow caused by relative motion between casing and rotor tip, and the pressure difference between pressure side and suction side at rotor tip, play important roles in tip clearance leakage flow. The more the rotor tip speed increases and tip clearance height decreases, the more the scraping effect acta. Though the leakage velocity of tip clearance at midsection and exducer regions changes less when the rotor rotational speed is changing, the distance between passage vortex and rotor suction side varies in evidence. Main leakage flow rate of tip clearance takes place at region of exducer tip and some seal configurations will be quite effective for cutting leakage flow if these configurations are arranged over midsection and exducer of the radial inflow rotor.

  20. Study on leakage flow characteristics of radial inflow turbines at rotor tip clearance

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Tip clearance leakage flow in a radial inflow turbine rotor for microturbines under the stage environment is investigated using a three-dimensional viscous flow simulation. The results indicate that the scraping flow caused by relative motion between casing and rotor tip, and the pressure difference between pressure side and suction side at rotor tip, play important roles in tip clearance leakage flow. The more the rotor tip speed increases and tip clearance height decreases, the more the scraping effect acts. Though the leakage velocity of tip clearance at midsection and exducer regions changes less when the rotor rotational speed is changing, the distance between passage vortex and rotor suction side varies in evidence. Main leakage flow rate of tip clearance takes place at region of exducer tip and some seal configurations will be quite effective for cutting leakage flow if these configurations are arranged over midsection and exducer of the radial inflow rotor.

  1. Application of thermometric methods for detection and characterization of leakages in embankment dams

    Energy Technology Data Exchange (ETDEWEB)

    Beck, Y.L.; Cunat, P.; Fry, J.J. [EDF, Grenoble (France); Faure, Y.H. [LTHE, Saint Martin d' Heres (France)

    2010-07-01

    The earliest possible detection of leakages in dikes is essential. Distributed temperature measurements using fibre optics allow the monitoring of large sections of the dike with a high spatial and temperature resolution. This paper presented the application of thermometric methods for detection and characterization of leakage in embankment dams. After a brief description of the system used, its application on a controlled experimental site and an EDF industrial site instrumented with fibre optics was presented. The instrumentation is complemented by installation of local temperature and pressure sensors in the piezometers for complete characterization of the detected leakages. The analysis of the results data clearly allowed detecting the leakages. The vertical location, intensity and location of the detected leakages were also identified. It was found that thermometry is potentially very powerful for detecting leaks and as a diagnostic tool.

  2. CSF Leakage "Radiology, Neuroradiology and Head and Neck, ENT"

    Directory of Open Access Journals (Sweden)

    Jalal Jalal Shokouhi

    2009-01-01

    Full Text Available Introduction: Leak of CSF is a relatively common complication in skull base fractures and it is rarely seen during skull base tumors and pituitary gland pathologies "Adenomas and empty sellae syndrome"."nThe common site of CSF leakage is related to the site of fracture but it is more common in cribriform plate fractures. Other sites are frontal sinus fractures and rarely sphenoid sinus lesions related to pituitary gland site pathology. Evaluation of the cribriform plate and the posterior wall of the frontal sinus is an imaging key point."nOther rare conditions of CSF leak are related to temporal bone fractures leading to otorrhea and in a paradoxical feature with rhinorrhea "intact tympanic membrane with temporal bone fracture and eustachian tube transmission of fluid"."nEthiology "nTrauma and skull base fractures epecially in the cribriform plate."nParanasal sinus fractures specially in the frontal and sphenoidal sinuses."nTemporal bone fractures."nEmpty sellae and intrasellar tumors."nPost-op stage in the skull base tumors."nDiagnosis"nNasal CSF leakage laboratory."nRadioneucleid imaging: This way is sensitive but non-specific."nMethylen blue injection into CSF via lumbar puncture "non-specific" and rarely used."nHigh resolution axial, coronal and sagittal reconstructed images of skull base as a modality of choice"nIn case of positive CSF leak but negative spiral ultra-high resolution CT in PNS, ethmoidal region and cribriform plate also temporal bone cuts we need linear and pleuridirectional X-ray tomography."nIn case of positive CSF leakage and negative radiology and imaging it needs exploration surgery to direct vision of anterior fossa floor bones for fracture."n-Companion complication could be recurrent meningitis."n- No 3D-CT or MRI is necessary for bone fractures but MRI could be"nnecessary for related brain contusion or soft tissue lesions and tumor."nX-ray CT-cisternography"nAlthough more than 90% of fractures could be detected by

  3. Characterization of CO2 leakage into the freshwater body

    Science.gov (United States)

    Singh, Ashok; Delfs, Jens-Olaf; Shao, Habing; Kolditz, Olaf

    2013-04-01

    Current research into Carbon dioxide Capture and Storage (CCS) is dominated by improving the CO2 storage capacity. However, potential leakage of CO2 can cause environmental problems, particularly if freshwater resources are nearby. In this regards, it is important to understand the chemistry of CO2 and the water system. CO2 leakage across the fluid interface (CO2 and water) is controlled by the difference in the partial pressure of CO2 in the storage and in the freshwater body. Once the CO2 is in solution, it equilibrates with the bicarbonate and carbonate ions. According to Millero (1994)such a system can be characterized by two parameters out of the four: total alkalinity (TA), total carbonate (TCO2), fugacity of CO2(fCO2) and pH. In the present modeling study, we are interested in the (i) CO2 leakage into a freshwater body (while injecting CO2 for storage) through an inclined fracture and (ii) characterization of the system by measuring fugacity of CO2 and pH. According to work presented by Singh et al. (2012), about 31% of injected CO2 leaks into the freshwater body. Solubility of CO2 in water follows Henry's law, while the Henry constant, K0 is calculated by an empirical relation developed by Murray and Riley (1971), which is a function of salinity and temperature. According to our results, pH and fugacity both appear to be a linear function of temperature. To simulate the discussed problem, a corresponding numerical module has been developed for multi-component fluid flow coupled with heat and mass transport processes. Governing equations and Volume Translated Peng-Robinson equations of state are implemented within the object-oriented finite element code OpenGeoSys (Kolditz et al., 2012; www.opengeosys.org). Primary variables are pressure, temperature and salinity which are obtained by solving the governing equations in a monolithic way The governing equations are discretized spatially within the context of a Galerkin approach, whereas the temporal

  4. Isolation and characterization of macromolecular protein R-Phycoerythrin from Portieria hornemannii.

    Science.gov (United States)

    Senthilkumar, Namasivayam; Suresh, Veeraperumal; Thangam, Ramar; Kurinjimalar, Chidambaram; Kavitha, Ganapathy; Murugan, Pitchai; Kannan, Soundarapandian; Rengasamy, Ramasamy

    2013-04-01

    R-Phycoerythrin (R-PE) is one of the three phycobiliproteins which are extensively used as fluorescent probes, and it is prepared from red macro-algae. This macromolecular protein has gained importance in many biotechnological applications in food science, immunodiagnostic, therapy, cosmetics, protein and cell labeling, and analytical processes. In the present investigation, R-PE was isolated and purified from a red alga Portieria hornemannii. R-PE extracted and purified through ammonium sulfate precipitation (55%) followed by Q-Sepharose column chromatography had yielded a maximum purity of 5.2%. R-PE exhibited a typical "three-peak" with absorption maxima at 499, 545 and 565 nm. CD spectrum of R-PE yielded the following secondary structure data: alpha helix (14.30%), beta helix (28.10%), turn helix (19.20%) and random coil helix (38.40%). The molecular mass of R-PE was 240 kDa under Native-PAGE. Three different subunits such as α, β and γ of 16 kDa, 21 kDa and 39 kDa were segregated under SDS-PAGE. On two dimensional gel electrophoresis, one basic and four acidic subunits were detected. Five different tryptic peptides were assigned under MALDI-TOF. The sequences of N-terminus of R-PE of 10 different amino acids are Met Lys Gln Met Trp Asp Arg Met Val Val. The preparative procedures of the R-PE extraction and purification established based on the experiments exhibit advantages and can offer a reference for R-PE preparation from other marine red macro-alga P. hornemannii.

  5. Prospects for Simulating Macromolecular Surfactant Chemistry at the Ocean-Atmosphere Boundary

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, S.; Burrows, Susannah M.; Deal, C.; Liu, Xiaohong; Long, M.; Ogunro, O.; Russell, Lynn M.; Wingenter, O.

    2014-05-01

    Biogenic lipids and polymers are surveyed for their ability to adsorb at the water-air interfaces associated with bubbles, marine microlayers and particles in the overlying boundary layer. Representative ocean biogeochemical regimes are defined in order to estimate local concentrations for the major macromolecular classes. Surfactant equilibria and maximum excess are then derived based on a network of model compounds. Relative local coverage and upward mass transport follow directly, and specific chemical structures can be placed into regional rank order. Lipids and denatured protein-like polymers dominate at the selected locations. The assigned monolayer phase states are variable, whether assessed along bubbles or at the atmospheric spray droplet perimeter. Since oceanic film compositions prove to be irregular, effects on gas and organic transfer are expected to exhibit geographic dependence as well. Moreover, the core arguments extend across the sea-air interface into aerosol-cloud systems. Fundamental nascent chemical properties including mass to carbon ratio and density depend strongly on the geochemical state of source waters. High surface pressures may suppress the Kelvin effect, and marine organic hygroscopicities are almost entirely unconstrained. While bubble adsorption provides a well-known means for transporting lipidic or proteinaceous material into sea spray, the same cannot be said of polysaccharides. Carbohydrates tend to be strongly hydrophilic so that their excess carbon mass is low despite stacked polymeric geometries. Since sugars are abundant in the marine aerosol, gel-based mechanisms may be required to achieve uplift. Uncertainties in the surfactant logic distill to a global scale dearth of information regarding two dimensional kinetics and equilibria. Nonetheless simulations are recommended, to initiate the process of systems level quantification.

  6. Free kick instead of cross-validation in maximum-likelihood refinement of macromolecular crystal structures

    International Nuclear Information System (INIS)

    The maximum-likelihood free-kick target, which calculates model error estimates from the work set and a randomly displaced model, proved superior in the accuracy and consistency of refinement of crystal structures compared with the maximum-likelihood cross-validation target, which calculates error estimates from the test set and the unperturbed model. The refinement of a molecular model is a computational procedure by which the atomic model is fitted to the diffraction data. The commonly used target in the refinement of macromolecular structures is the maximum-likelihood (ML) function, which relies on the assessment of model errors. The current ML functions rely on cross-validation. They utilize phase-error estimates that are calculated from a small fraction of diffraction data, called the test set, that are not used to fit the model. An approach has been developed that uses the work set to calculate the phase-error estimates in the ML refinement from simulating the model errors via the random displacement of atomic coordinates. It is called ML free-kick refinement as it uses the ML formulation of the target function and is based on the idea of freeing the model from the model bias imposed by the chemical energy restraints used in refinement. This approach for the calculation of error estimates is superior to the cross-validation approach: it reduces the phase error and increases the accuracy of molecular models, is more robust, provides clearer maps and may use a smaller portion of data for the test set for the calculation of Rfree or may leave it out completely

  7. X-ray detectors for soft X-ray macromolecular crystallography

    International Nuclear Information System (INIS)

    Full text: Modern protein crystallography ultimately makes use of the two-dimensional position - sensitive detectors such as Image Plates and CCD with scintillation convertors coupled with fiber optics for detection of X-Ray diffraction pictures taken from macromolecular crystals. These detectors have high efficiency for 1.5-1.0 A synchrotron radiation, special resolution ∼80-50 μm and large effective area (i.e. Σ 300 mm2 for large MAR Image Plate). Both of these types of detectors lack energy resolution. A major drawback of Image Plates is long read-out time (2.5-4 minutes). CCD based devices permit data collection in a real time, however at present they are much more expensive. One of the novel and very promising trends in protein crystallography is to use soft X-ray synchrotron radiation between 2.2 keV and 6 keV (5.6 to 2.5 A) and there is an urgent need to develop suitable detection system for these kinds of applications. It is to be two- dimensional positional sensitive detector with pitch of about 10 to 20 μm, high efficiency and real-time readout. An active area of the detector is to be at least 20 x 20 mm2. It seems to be the simplest solution to use conventional direct-illumination CCD detectors because absorption length of the 5 A radiation in silicon is about 3 μm. However they lack, for example, energy resolution and optimum solution of the problem has yet to come. (author)

  8. Improving 2D and 3D Skin In Vitro Models Using Macromolecular Crowding.

    Science.gov (United States)

    Benny, Paula; Badowski, Cedric; Lane, E Birgitte; Raghunath, Michael

    2016-01-01

    The glycoprotein family of collagens represents the main structural proteins in the human body, and are key components of biomaterials used in modern tissue engineering. A technical bottleneck is the deposition of collagen in vitro, as it is notoriously slow, resulting in sub-optimal formation of connective tissue and subsequent tissue cohesion, particularly in skin models. Here, we describe a method which involves the addition of differentially-sized sucrose co-polymers to skin cultures to generate macromolecular crowding (MMC), which results in a dramatic enhancement of collagen deposition. Particularly, dermal fibroblasts deposited a significant amount of collagen I/IV/VII and fibronectin under MMC in comparison to controls. The protocol also describes a method to decellularize crowded cell layers, exposing significant amounts of extracellular matrix (ECM) which were retained on the culture surface as evidenced by immunocytochemistry. Total matrix mass and distribution pattern was studied using interference reflection microscopy. Interestingly, fibroblasts, keratinocytes and co-cultures produced cell-derived matrices (CDM) of varying composition and morphology. CDM could be used as "bio-scaffolds" for secondary cell seeding, where the current use of coatings or scaffolds, typically from xenogenic animal sources, can be avoided, thus moving towards more clinically relevant applications. In addition, this protocol describes the application of MMC during the submerged phase of a 3D-organotypic skin co-culture model which was sufficient to enhance ECM deposition in the dermo-epidermal junction (DEJ), in particular, collagen VII, the major component of anchoring fibrils. Electron microscopy confirmed the presence of anchoring fibrils in cultures developed with MMC, as compared to controls. This is significant as anchoring fibrils tether the dermis to the epidermis, hence, having a pre-formed mature DEJ may benefit skin graft recipients in terms of graft stability and

  9. Electrostatic, elastic and hydration-dependent interactions in dermis influencing volume exclusion and macromolecular transport.

    Science.gov (United States)

    Øien, Alf H; Wiig, Helge

    2016-07-01

    Interstitial exclusion refers to the limitation of space available for plasma proteins and other macromolecules based on collagen and negatively charged glycosaminoglycans (GAGs) in the interstitial space. It is of particular importance to interstitial fluid and plasma volume regulation. Here we present a novel mechanical and mathematical model of the dynamic interactions of structural elements within the interstitium of the dermis at the microscopic level that may explain volume exclusion of charged and neutral macroparticles. At this level, the interstitium is considered to consist of elements called extracellular matrix (ECM) cells, again containing two main interacting structural components on a fluid background including anions and cations setting up osmotic forces: one smaller GAG component, having an intrinsic expansive electric force, and one bigger collagen component, having an intrinsic elastic force. Because of size differences, the GAG component interacts with a fraction of the collagen component only at normal hydration. This fraction, however, increases with rising hydration as a consequence of the modeled form of the interaction force between the GAGs and collagen. Collagen is locally displaced at variable degrees as hydration changes. Two models of GAGs are considered, having largely different geometries which demands different, but related, forms of GAG-collagen interaction forces. The effects of variable fixed charges on GAGs and of GAG density in tissue are evaluated taking into account observed volume exclusion properties of charged macromolecules as a function of tissue hydration. The presented models may improve our biophysical understanding of acting forces influencing tissue fluid dynamics. Such knowledge is significant when evaluating the transport of electrically charged and neutral macromolecules into and through the interstitium, and therefore to drug uptake and the therapeutic effects of macromolecular agents. PMID:27079466

  10. Room-temperature macromolecular crystallography using a micro-patterned silicon chip with minimal background scattering

    Science.gov (United States)

    Roedig, Philip; Duman, Ramona; Sanchez-Weatherby, Juan; Vartiainen, Ismo; Burkhardt, Anja; Warmer, Martin; David, Christian; Wagner, Armin; Meents, Alke

    2016-01-01

    Recent success at X-ray free-electron lasers has led to serial crystallography experiments staging a comeback at synchrotron sources as well. With crystal lifetimes typically in the millisecond range and the latest-generation detector technologies with high framing rates up to 1 kHz, fast sample exchange has become the bottleneck for such experiments. A micro-patterned chip has been developed from single-crystalline silicon, which acts as a sample holder for up to several thousand microcrystals at a very low background level. The crystals can be easily loaded onto the chip and excess mother liquor can be efficiently removed. Dehydration of the crystals is prevented by keeping them in a stream of humidified air during data collection. Further sealing of the sample holder, for example with Kapton, is not required. Room-temperature data collection from insulin crystals loaded onto the chip proves the applicability of the chip for macromolecular crystallography. Subsequent structure refinements reveal no radiation-damage-induced structural changes for insulin crystals up to a dose of 565.6 kGy, even though the total diffraction power of the crystals has on average decreased to 19.1% of its initial value for the same dose. A decay of the diffracting power by half is observed for a dose of D 1/2 = 147.5 ± 19.1 kGy, which is about 1/300 of the dose before crystals show a similar decay at cryogenic temperatures. PMID:27275143

  11. Connexin26 regulates assembly and maintenance of cochlear gap junction macromolecular complex for normal hearing

    Science.gov (United States)

    Kamiya, Kazusaku; Fukunaga, Ichiro; Hatakeyama, Kaori; Ikeda, Katsuhisa

    2015-12-01

    Hereditary deafness affects about 1 in 2000 children and GJB2 gene mutation is most frequent cause for this disease in the world. GJB2 encodes connexin26 (Cx26), a component in cochlear gap junction. Recently, we found macromolecular change of gap junction plaques with two different types of Cx26 mutation as major classification of clinical case, one is a model of dominant negative type, Cx26R75W+ and the other is conditional gene deficient mouse, Cx26f/fP0Cre as a model for insufficiency of gap junction protein [6]. Gap junction composed mainly of Cx26 and Cx30 in wild type mice formed large planar gap junction plaques (GJP). In contrast, Cx26R75W+ and Cx26f/fP0Cre showed fragmented small round GJPs around the cell border. In Cx26f/fP0Cre, some of the cells with Cx26 expression due to their cellular mosaicism showed normal large GJP with Cx26 and Cx30 only at the cell junction site between two Cx26 positive cells. These indicate that bilateral Cx26 expressions from both adjacent cells are essential for the formation of the cochlear linear GJP, and it is not compensated by other cochlear Connexins such as Connexin30. In the present study, we demonstrated a new molecular pathology in most common hereditary deafness with different types of Connexin26 mutations, and this machinery can be a new target for drag design of hereditary deafness.

  12. Degradation of Leakage Currents and Reliability Prediction for Tantalum Capacitors

    Science.gov (United States)

    Teverovsky, Alexander

    2016-01-01

    Two types of failures in solid tantalum capacitors, catastrophic and parametric, and their mechanisms are described. Analysis of voltage and temperature reliability acceleration factors reported in literature shows a wide spread of results and requires more investigation. In this work, leakage currents in two types of chip tantalum capacitors were monitored during highly accelerated life testing (HALT) at different temperatures and voltages. Distributions of degradation rates were approximated using a general log-linear Weibull model and yielded voltage acceleration constants B = 9.8 +/- 0.5 and 5.5. The activation energies were Ea = 1.65 eV and 1.42 eV. The model allows for conservative estimations of times to failure and was validated by long-term life test data. Parametric degradation and failures are reversible and can be annealed at high temperatures. The process is attributed to migration of charged oxygen vacancies that reduce the barrier height at the MnO2/Ta2O5 interface and increase injection of electrons from the MnO2 cathode. Analysis showed that the activation energy of the vacancies' migration is 1.1 eV.

  13. Feasibility study of tank leakage mitigation using subsurface barriers

    Energy Technology Data Exchange (ETDEWEB)

    Treat, R.L.; Peters, B.B.; Cameron, R.J.; McCormak, W.D.; Trenkler, T.; Walters, M.F. [Ensearch Environmental, Inc. (United States); Rouse, J.K.; McLaughlin, T.J. [Bovay Northwest, Inc., Richland, WA (United States); Cruse, J.M. [Westinghouse Hanford Co., Richland, WA (United States)

    1994-09-21

    The US Department of Energy (DOE) has established the Tank Waste Remediation System (TWRS) to satisfy manage and dispose of the waste currently stored in the underground storage tanks. The retrieval element of TWRS includes a work scope to develop subsurface impermeable barriers beneath SSTs. The barriers could serve as a means to contain leakage that may result from waste retrieval operations and could also support site closure activities by facilitating cleanup. Three types of subsurface barrier systems have emerged for further consideration: (1) chemical grout, (2) freeze walls, and (3) desiccant, represented in this feasibility study as a circulating air barrier. This report contains analyses of the costs and relative risks associated with combinations retrieval technologies and barrier technologies that from 14 alternatives. Eight of the alternatives include the use of subsurface barriers; the remaining six nonbarrier alternative are included in order to compare the costs, relative risks and other values of retrieval with subsurface barriers. Each alternative includes various combinations of technologies that can impact the risks associated with future contamination of the groundwater beneath the Hanford Site to varying degrees. Other potential risks associated with these alternatives, such as those related to accidents and airborne contamination resulting from retrieval and barrier emplacement operations, are not quantitatively evaluated in this report.

  14. Feasibility study of tank leakage mitigation using subsurface barriers

    International Nuclear Information System (INIS)

    The US Department of Energy (DOE) has established the Tank Waste Remediation System (TWRS) to satisfy manage and dispose of the waste currently stored in the underground storage tanks. The retrieval element of TWRS includes a work scope to develop subsurface impermeable barriers beneath SSTs. The barriers could serve as a means to contain leakage that may result from waste retrieval operations and could also support site closure activities by facilitating cleanup. Three types of subsurface barrier systems have emerged for further consideration: (1) chemical grout, (2) freeze walls, and (3) desiccant, represented in this feasibility study as a circulating air barrier. This report contains analyses of the costs and relative risks associated with combinations retrieval technologies and barrier technologies that from 14 alternatives. Eight of the alternatives include the use of subsurface barriers; the remaining six nonbarrier alternative are included in order to compare the costs, relative risks and other values of retrieval with subsurface barriers. Each alternative includes various combinations of technologies that can impact the risks associated with future contamination of the groundwater beneath the Hanford Site to varying degrees. Other potential risks associated with these alternatives, such as those related to accidents and airborne contamination resulting from retrieval and barrier emplacement operations, are not quantitatively evaluated in this report

  15. Structural and leakage integrity assessment of WWER steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Splichal, K.; Otruba, J. [Nuclear Research Inst., Rez (Switzerland)

    1997-12-31

    The integrity of heat exchange tubes may influence the life-time of WWER steam generators and appears to be an important criterion for the evaluation of their safety and operational reliability. The basic requirement is to assure a very low probability of radioactive water leakage, preventing unstable crack growth and sudden tube rupture. These requirements led to development of permissible limits for primary to secondary leak evolution and heat exchange tubes plugging based on eddy current test inspection. The stress corrosion cracking and pitting are the main corrosion damage of WWER heat exchange tubes and are initiated from the outer surface. They are influenced by water chemistry, temperature and tube wall stress level. They take place under crevice corrosion condition and are indicated especially (1) under the tube support plates, where up to 90-95 % of defects detected by the ECT method occur, and (2) on free spans under tube deposit layers. Both the initiation and crack growth cause thinning of the tube wall and lead to part thickness cracks and through-wall cracks, oriented above all in the axial direction. 10 refs.

  16. Compensation for Booster Leakage Field in the Duke Storage Ring

    CERN Document Server

    Li, Wei; Mikhailov, Stepan F; Popov, Victor; Li, Wei-Min; Wu, Ying K

    2016-01-01

    The High Intensity Gamma-ray Source (HIGS) at Duke University is an accelerator-driven Compton gamma-ray source, providing high flux gamma-ray beam from 1 MeV to 100 MeV for photo-nuclear physics research. The HIGS facility operates three accelerators, a linac pre-injector (0.16 GeV), a booster injector (0.16-1.2 GeV), and an electron storage ring (0.24-1.2 GeV). Because of proximity of the booster injector to the storage ring, the magnetic field of the booster dipoles close to the ring can significantly alter the closed orbit in the storage ring being operated in the low energy region. This type of orbit distortion can be a problem for certain precision experiments which demand a high degree of the energy consistency of the gamma-ray beam. This energy consistency can be achieved by maintaining consistent aiming of the gamma-ray beam, therefore, a steady electron beam orbit and angle at the Compton collision point. To overcome the booster leakage field problem, we have developed an orbit compensation scheme. ...

  17. Smart integrated containment leakage rate test system using wireless communication

    International Nuclear Information System (INIS)

    Integrated Leakage Rate Test (ILRT) is the important test the confidentiality and integrity of the containment building, which is the last barrier when Design basis accidents (DBA) of Nuclear Power plant occur. Since the result of this test is the basis to guarantee the safety of nuclear power plants, the test process, test procedure, and the test equipment are required to have high reliability. The test devices previously used have been products of VOLUMERTRICS and GRAFTEL of USA. These devices have been inconvenient to calibrate and use. Thus improved devices needed to be developed to remove the inconveniences, to verify the safety of Korean nuclear power plants with Korea's own technology, and to secure core technology. A new leak test system was developed by domestic technology for that purpose and needed to be verified. In this paper, technical details of the newly developed easy to use and highly reliable measuring test device, which is in operation at the nuclear power plant sites, will be introduced. State of art technology was applied to the device to address the shortcomings of previous US made devices and the difficulties to use on site

  18. Simulation of magnetic flux leakage: Application to tube inspection

    Science.gov (United States)

    Prémel, Denis; Fnaeich, E. A.; Djafa, S.; Pichon, L.; Trillon, A.; Bisiaux, B.

    2012-05-01

    The detection of flaws in steel pipes using Magnetic Flux Leakage (MFL) consists in detecting magnetic flux leaks outside the pipe, either with a magnetic sensor or with an induction coil, while the pipe is rotating. In the Vallourec group, many NDT units use MFL for testing ferromagnetic pipes. In order to improve the performances of flaw detection, CEA LIST and the Vallourec Research Aulnoye (VRA) group are collaborating on MFL modelling. The aim is to be able to perform parametric studies thanks to a fast 3D numerical model dedicated to MFL systems. A simplified 2D geometry has already been derived for the development of first simulation tools. When considering the B-H curve of ferromagnetic materials, the non-linear magnetostatic problem can be solved with the generalized boundary element method (BEMG), which comes to the evaluation of two equivalent scalar potentials: the surface charge density and the volume charge density. When applying the Galerkin method for the discretization of integral equations, the particularity of this numerical model lies in the implementation of high order basis functions for the interpolation of the scalar unknowns. This paper presents some first numerical results for the numerical validation of the semi-analytical model.

  19. Airborne Detection and Tracking of Geologic Leakage Sites

    Science.gov (United States)

    Jacob, Jamey; Allamraju, Rakshit; Axelrod, Allan; Brown, Calvin; Chowdhary, Girish; Mitchell, Taylor

    2014-11-01

    Safe storage of CO2 to reduce greenhouse gas emissions without adversely affecting energy use or hindering economic growth requires development of monitoring technology that is capable of validating storage permanence while ensuring the integrity of sequestration operations. Soil gas monitoring has difficulty accurately distinguishing gas flux signals related to leakage from those associated with meteorologically driven changes of soil moisture and temperature. Integrated ground and airborne monitoring systems are being deployed capable of directly detecting CO2 concentration in storage sites. Two complimentary approaches to detecting leaks in the carbon sequestration fields are presented. The first approach focuses on reducing the requisite network communication for fusing individual Gaussian Process (GP) CO2 sensing models into a global GP CO2 model. The GP fusion approach learns how to optimally allocate the static and mobile sensors. The second approach leverages a hierarchical GP-Sigmoidal Gaussian Cox Process for airborne predictive mission planning to optimally reducing the entropy of the global CO2 model. Results from the approaches will be presented.

  20. Leakage radiation spectroscopy of organic/dielectric/metal systems

    DEFF Research Database (Denmark)

    Fiutowski, Jacek; Kawalec, Tomasz; Kostiučenko, Oksana;

    2014-01-01

    excitons and surface plasmon polaritons (SPPs) of the metal/dielectric boundary. The presence of the SiO2 layer considerably changes the dispersion curve in comparison to the one of the Ag/p-6P/air system. However, the Ag/SiO2/p-6P/air stack forms a stable structure allowing construction of organic......Leakage radiation spectroscopy of organic para-Hexaphenylene (p-6P) molecules has been performed in the spectral range 420-675 nm which overlaps with the p-6P photoluminescence band. The p-6P was deposited on 40 nm silver (Ag) films on BK7 glass, covered with SiO2 layers. The SiO2 layer thickness...... was varied in the range 5-30 nm. Domains of mutually parallelly oriented organic nanofibers were initially grown under high-vacuum conditions by molecular beam epitaxy onto a cleaved muscovite mica substrate and afterwards transferred onto the sample by a soft transfer technique. The sample placed on a flat...

  1. Anastomotic leakage after colorectal surgery: diagnostic accuracy of CT

    Energy Technology Data Exchange (ETDEWEB)

    Kauv, Paul; Benadjaoud, Samir; Boulay-Coletta, Isabelle; Zins, Marc [Fondation Hopital Saint-Joseph, Department of Radiology, Paris (France); Curis, Emmanuel [Universite Paris Descartes, Laboratoire de biomathematiques, Faculte de pharmacie, Paris (France); Loriau, Jerome [Fondation Hopital Saint-Joseph, Department of Digestive Surgery, Paris (France)

    2015-12-15

    To evaluate the diagnostic accuracy of CT in postoperative colorectal anastomotic leakage (AL). Two independent blinded radiologists reviewed 153 CTs performed for suspected AL within 60 days after surgery in 131 consecutive patients, with (n = 58) or without (n = 95) retrograde contrast enema (RCE). Results were compared to original interpretations. The reference standard was reoperation or consensus (a radiologist and a surgeon) regarding clinical, laboratory, radiological, and follow-up data after medical treatment. AL was confirmed in 34/131 patients. For the two reviewers and original interpretation, sensitivity of CT was 82 %, 87 %, and 71 %, respectively; specificity was 84 %, 84 %, and 92 %. RCE significantly increased the positive predictive value (from 40 % to 88 %, P = 0.0009; 41 % to 92 %, P = 0.0016; and 40 % to 100 %, P = 0.0006). Contrast extravasation was the most sensitive (reviewers, 83 % and 83 %) and specific (97 % and 97 %) sign and was significantly associated with AL by univariate analysis (P < 0.0001 and P < 0.0001). By multivariate analysis with recursive partitioning, CT with RCE was accurate to confirm or rule out AL with contrast extravasation. CT with RCE is accurate for diagnosing postoperative colorectal AL. Contrast extravasation is the most reliable sign. RCE should be performed during CT for suspected AL. (orig.)

  2. Aging changes of macromolecular synthesis in the digestive organs of mice as revealed by microscopic radioautography and X-ray microanalysis

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Tetsuji [Shinshu Univ., Matsumoto (Japan). School of Medicine. Dept. of Anatomy and Cell Biology]. E-mail: nagatas@po.cnet.ne.jp

    2002-07-01

    For the purpose of elucidating the aging changes of macromolecular synthesis such as DNA, RNA, proteins, glycoproteins, glycides and lipids in various organ systems of experimental animals, we have studied the digestive organs of aging mice and rats as a series of systematic studies using light and electron microscopic radioautography after incorporations with macromolecular precursors. The experimental animals mainly used were ddY strain mice at various aging groups from embryo to postnatal days 1 and 3, weeks 1 and 2, months 1, 2, 6, 12 up to 2 year senescent stages as well as several groups of adult Wistar rats. The animals were injected with such macromolecular precursors as {sup 3}H - thymidine for DNA, {sup 3}H-uridine for RNA, {sup 3}H-leucine and {sup 3}H proline for proteins, {sup 35}SO{sub 4} for glycoproteins, {sup 3} H-glucosamine for glucides and {sup 3}H-glycerol for lipids. The results demonstrated that these precursors were incorporated into various cell types in the oral cavity, the salivary glands, the esophagus, the stomach, the small and large intestines, the liver and the pancreas at various ages from perinatal to juvenile, mature and senescent stages, showing specific patterns of macromolecular synthesis. It is concluded that these specific patterns of macromolecular synthesis in respective cell types demonstrated the organ specificity of aging of animals. (author)

  3. Evaluation of the effects of enameloplasty and air abrasion on sealant micro-leakage.

    Directory of Open Access Journals (Sweden)

    Aliasghar Soleymani

    2014-12-01

    Full Text Available Micro-leakage, one of the major reasons for recurrent decays, may lead to uncontrollable flow of liquids, pulp inflammation and peri-apical pathology. The purpose of this in vitro study was to evaluate micro-leakage of pit and fissure sealants after using three different pit and fissure preparation techniques: 1 acid etching, 2 fissure enameloplasty and acid etching, and 3 air abrasion and acid etching.Sixty-nine extracted sound molars and premolars were randomly divided into three groups (23 samples in each group. Teeth were prepared using one of three occlusal surface treatments. Then the sealant was applied on the occlusal fissures of all teeth. The teeth were thermocycled and stored in normal saline. All teeth were sealed apically and coated with nail varnish and then were immersed in a 2% solution of methylen blue. Two buccolingual sections were made. The surfaces were scored 0 to 3 for the extent of micro-leakage using a stereomicroscope. Data were analyzed by Kruskal- wallis and Dunn procedure.Enameloplasty and acid etching were significantly different regarding micro-leakage (P= 0.016, but no significant difference in micro-leakage was observed between air abrasion and the other methods.Enameloplasty followed by acid etching produced significantly less micro-leakage than the acid etching technique. Air abrasion acid etching was better than the acid etching technique in reducing micro-leakage too.

  4. A new on-line leakage current monitoring system of ZnO surge arresters

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Bok-Hee [Research Center for Next-Generation High Voltage and Power Technology, Inha University, 253 Yonghyun-dong, Nam-ku, Incheon 402-751 (Korea, Republic of)]. E-mail: bhlee@inha.ac.kr; Kang, Sung-Man [Research Center for Next-Generation High Voltage and Power Technology, Inha University, 253 Yonghyun-dong, Nam-ku, Incheon 402-751 (Korea, Republic of)

    2005-05-15

    This paper presents a new on-line leakage current monitoring system of zinc oxide (ZnO) surge arresters. To effectively diagnose the deterioration of ZnO surge arresters, a new algorithm and on-line leakage current detection device, which uses the time-delay addition method, for discriminating the resistive and capacitive currents was developed to use in the aging test and durability evaluation for ZnO arrester blocks. A computer-based measurement system of the resistive leakage current, the on-line monitoring device can detect accurately the leakage currents flowing through ZnO surge arresters for power frequency ac applied voltages. The proposed on-line leakage current monitoring device of ZnO surge arresters is more highly sensitive and gives more linear response than the existing devices using the detection method of the third harmonic leakage currents. Therefore, the proposed leakage current monitoring device can be useful for predicting the defects and performance deterioration of ZnO surge arresters in power system applications.

  5. Mitral Valve Replacement with Half-and-Half Technique for Recurrent Mitral Paravalvular Leakage.

    Science.gov (United States)

    Morisaki, Akimasa; Kato, Yasuyuki; Takahashi, Yosuke; Shibata, Toshihiko

    2015-05-01

    Reoperation for paravalvular leakage can cause recurrent paravalvular leakage through severe damage to the mitral annulus. Previously, mitral valve replacement using a half-and-half technique for extensive mitral annular calcification was reported; here, application of the technique to treat recurrent paravalvular leakage is described. A 78-year-old male with three prior mitral valve replacements developed recurrent paravalvular leakage, for which he had undergone his third mitral valve replacement at the age of 69 years. On this occasion, a mechanical valve with circumferential equine pericardial patch reinforcement of the annulus had been used. Five years later, the patient developed hemolytic anemia and congestive heart failure due to recurrent paravalvular leakage. Intraoperatively, broad dehiscence was seen between the prosthetic valve and mitral annulus at two sites, the anterior and posterior commissures, without infection. A fourth mitral valve replacement was performed with a St. Jude Medical valve, using a half-and-half technique. This entailed the use of non-everting mattress sutures on the anterior half of the annulus, and everting mattress sutures on the left atrial wall around the posterior half of the annulus. Extensive annular defects required reinforcement of the posterior mitral annulus with a bovine pericardial patch. Postoperative echocardiography showed no paravalvular leakage. The half-and-half technique may be useful in treating recurrent paravalvular leakage of the mitral valve. PMID:26901904

  6. A Novel Technique: Data Leakage Hindering in Cloud computing using Swarm Intelligence

    Directory of Open Access Journals (Sweden)

    C. Suresh Kumar

    2014-12-01

    Full Text Available Cloud computing is based on network based computing with the intention of takes place over the Internet. The cloud computing is a culmination of numerous attempts at large scale computing with seamless access to virtually limitless resources. It has many of the assistances such as cost effective, increased storage, shared resources, easy backup and restoration. Although there would be some challenges at some point in of the data diffusion in the cloud computing. The main objective of this context is to spotlight the issue of data security and privacy, probable to be data leakages in the cloud services. This paper initiates a novel scheme, Impeding Data Leakage technique in the cloud computing. This novel technique involved in hampering the leakage of data due to intrusions in the transmission pathway and not to detect or prevent the intrusion, it would lead to halt the entire data leakage with that meticulous path. The objective of this paper is to integrate ant colony optimization technique (ACO with artificial bee colony technique (ABC, for the intention of hampering the communication path which is interrupted/ the data is leaked. Thus, the ABC crafts the probable and conscientious path to the server and the ACO responses for the requested path and it would back forward the information if the data leakage arises. The leakage of data would be originated with the security restraints by the ACO. Therefore, the ABC and ACO are integrated to make a halt to the data leakage in the cloud service

  7. Leakage diagnostics, sealant longevity, sizing and technology transfer in residential thermal distribution systems

    Energy Technology Data Exchange (ETDEWEB)

    Walker, I.; Sherman, M.; Modera, M.; Siegel, J.

    1998-01-01

    This field study concentrated on measurement of duct leakage to outside the conditioned space because this is most useful in energy calculations. For room by room load/comfort requirements, the total duct leakage (including leaks to conditioned space) is more appropriate, particularly for additional comfort considerations. The objective of this field study is to help to identify major sources of uncertainty and to quantify the trade offs between different test methods. The identification of the areas requiring significant improvement will aid in future development of duct leakage test methods. For example, during the course of this study a new method for correcting house pressure tests to account for the presence of duct leakage in measured envelope leakage was developed. Each of the measurement techniques investigated has resulted from a different set of priorities and hence compromises. Thus each one of them is measuring a different physical quantity, although they all report the same parameter; duct leakage to outside at operating conditions. Given that real houses do not meet all of the simplifying assumptions that must be made to achieve similarity, the same numbers from each test method are not expected. Potentially these differences can be quite large and one of the benefits of field measurement is that the differences in the measurements helps put a realistic bound on how different some of these leakage diagnostics may be.

  8. CT evaluation of local leakage of bone cement after percutaneous kyphoplasty and vertebroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Lee, In Jae; Choi, A. Lam; Yie, Mi-Yeon; Yoon, Ji Young; Jeon, Eui Yong; Koh, Sung Hye; Yoon, Dae Young; Lim, Kyung Ja (Dept. of Radiology, Hallym Univ. Sacred Heart Hospital, Seoul (Korea)), e-mail: ijlee2003@medimail.co.kr; Im, Hyoung June (Dept. of Occupational Medicine, Hallym Univ. College of Medicine, Seoul (Korea))

    2010-07-15

    Background: Percutaneous injection of bone cement (acrylic cement) during percutaneous kyphoplasty and vertebroplasty can cause symptomatic or asymptomatic complications due to leakage, extravasation or vascular migration of cement. Purpose: To investigate and to compare the incidence and site of local leakage or complications of bone cement after percutaneous kyphoplasty and vertebroplasty using bone cement. Material and Methods: We retrospectively reviewed 473 cases of percutaneous kyphoplasty or vertebroplasty performed under fluoroscopic guidance. Of the 473 cases, follow-up CT scans that covered the treated bones were available for 83 cases (59 kyphoplasty and 24 vertebroplasty). Results: The rate of local leakage of bone cement was 87.5% (21/24) for percutaneous vertebroplasty and 49.2% (29/59) for kyphoplasty. The most common site of local leakage was perivertebral soft tissue (n=8, 38.1%) for vertebroplasty. The most common site of local leakage was a perivertebral vein (n=7, 24.1%) for kyphoplasty. Two cases of pulmonary cement embolism developed: one case after kyphoplasty and one case after vertebroplasty. Conclusion: Local leakage of bone cement was more common for percutaneous vertebroplasty compared with kyphoplasty (P<0.005). The most common sites of local leakage were perivertebral soft tissue and perivertebral vein.

  9. Enhanced ground bounce noise reduction in a low-leakage CMOS multiplier

    Science.gov (United States)

    Verma, Bipin Kumar; Akashe, Shyam; Sharma, Sanjay

    2015-09-01

    In this paper, various parameters are used to reduce leakage power, leakage current and noise margin of circuits to enhance their performance. A multiplier is proposed with low-leakage current and low ground bounce noise for the microprocessor, digital signal processors (DSP) and graphics engines. The ground bounce noise problem appears when a conventional power-gating circuit transits from sleep-to-active mode. This paper discusses a reduction in leakage current in the stacking power-gating technique by three modes - sleep, active and sleep-to-active. The simulation results are performed on a 4 × 4 carry-save multiplier for leakage current, active power, leakage power and ground bounce noise, and comparison made for different nanoscales. Ground bounce noise is limited to 90%. The leakage current of the circuit is decimated up to 80% and the active power is reduced to 31%. We performed simulations using cadence virtuoso 180 and 45 nm at room temperature at various supply voltages.

  10. Modeling the leakage of LCD displays with local backlight for quality assessment

    Science.gov (United States)

    Mantel, Claire; Korhonen, Jari; Pedersen, Jesper M.; Bech, Søren; Nadernejad, Ehsan; Burini, Nino; Forchhammer, Søren

    2014-02-01

    The recent technique of local backlight dimming has a significant impact on the quality of images displayed with a LCD screen with LED local dimming. Therefore it represents a necessary step in the quality assessment chain, independently from the other processes applied to images. This paper investigates the modeling of one of the major spatial artifacts produced by local dimming: leakage. Leakage appears in dark areas when the backlight level is too high for LC cells to block sufficiently and the final displayed brightness is higher than it should. A subjective quality experiment was run on videos displayed on LCD TV with local backlight dimming viewed from a 0° and 15° angles. The subjective results are then compared objective data using different leakage models: constant over the whole display or horizontally varying and three leakage factor (no leakage, measured at 0° and 15° respectively). Results show that for dark sequences accounting for the leakage artifact in the display model is definitely an improvement. Approximating that leakage is constant over the screen seems valid when viewing from a 15° angle while using a horizontally varying model might prove useful for 0° viewing.

  11. β-Cyclodextrin-Based Inclusion Complexation Bridged Biodegradable Self-Assembly Macromolecular Micelle for the Delivery of Paclitaxel.

    Directory of Open Access Journals (Sweden)

    Yanzuo Chen

    Full Text Available In this study, a novel adamantanamine-paclitaxel (AD-PTX incorporated oligochitosan- carboxymethyl-β-cyclodextrin (CSO-g-CM-β-CD self-assembly macromolecular (CSO-g-CM-β-CD@AD-PTX micelle was successfully prepared in water through sonication. The formed molecules were characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance (NMR spectroscopy, two-dimensional NMR, elemental analysis, and liquid chromatography-mass spectrometry, while the correspondent micelles were characterized by dynamic light scattering and transmission electron microscopy. We showed that the macromolecular micelle contained a spherical core-shell structure with a diameter of 197.1 ± 3.3 nm and zeta potential of -19.1 ± 4.3 mV. The CSO-g-CM-β-CD@AD-PTX micelle exhibited a high drug-loading efficacy up to 31.3%, as well as a critical micelle concentration of 3.4 × 10-7 M, which indicated good stability. Additionally, the in vitro release profile of the CSO-g-CM-β-CD@AD-PTX micelle demonstrated a long-term release pattern, 63.1% of AD-PTX was released from the micelle during a 30-day period. Moreover, the CSO-g-CM-β-CD@AD-PTX micelle displayed cytotoxicity at a sub-μM scale similar to PTX in U87 MG cells, and CSO-g-CM-β-CD exhibited a good safety profile by not manifesting significant toxicity at concentrations up to 100 μM. These results indicated that β-CD-based inclusion complexation resulting in biodegradable self-assembled macromolecular micelles can be utilized as nanocarrier, and may provide a promising platform for drug delivery in the future medical applications.

  12. Permeability to macromolecular contrast media quantified by dynamic MRI correlates with tumor tissue assays of vascular endothelial growth factor (VEGF)

    International Nuclear Information System (INIS)

    Purpose: To correlate dynamic MRI assays of macromolecular endothelial permeability with microscopic area–density measurements of vascular endothelial growth factor (VEGF) in tumors. Methods and material: This study compared tumor xenografts from two different human cancer cell lines, MDA-MB-231 tumors (n = 5), and MDA-MB-435 (n = 8), reported to express respectively higher and lower levels of VEGF. Dynamic MRI was enhanced by a prototype macromolecular contrast medium (MMCM), albumin-(Gd-DTPA)35. Quantitative estimates of tumor microvascular permeability (KPS; μl/min × 100 cm3), obtained using a two-compartment kinetic model, were correlated with immunohistochemical measurements of VEGF in each tumor. Results: Mean KPS was 2.4 times greater in MDA-MB-231 tumors (KPS = 58 ± 30.9 μl/min × 100 cm3) than in MDA-MB-435 tumors (KPS = 24 ± 8.4 μl/min × 100 cm3) (p < 0.05). Correspondingly, the area–density of VEGF in MDA-MB-231 tumors was 2.6 times greater (27.3 ± 2.2%, p < 0.05) than in MDA-MB-435 cancers (10.5 ± 0.5%, p < 0.05). Considering all tumors without regard to cell type, a significant positive correlation (r = 0.67, p < 0.05) was observed between MRI-estimated endothelial permeability and VEGF immunoreactivity. Conclusion: Correlation of MRI assays of endothelial permeability to a MMCM and VEGF immunoreactivity of tumors support the hypothesis that VEGF is a major contributor to increased macromolecular permeability in cancers. When applied clinically, the MMCM-enhanced MRI approach could help to optimize the appropriate application of VEGF-inhibiting therapy on an individual patient basis.

  13. β-Cyclodextrin-Based Inclusion Complexation Bridged Biodegradable Self-Assembly Macromolecular Micelle for the Delivery of Paclitaxel.

    Science.gov (United States)

    Chen, Yanzuo; Huang, Yukun; Qin, Dongdong; Liu, Wenchao; Song, Chao; Lou, Kaiyan; Wang, Wei; Gao, Feng

    2016-01-01

    In this study, a novel adamantanamine-paclitaxel (AD-PTX) incorporated oligochitosan- carboxymethyl-β-cyclodextrin (CSO-g-CM-β-CD) self-assembly macromolecular (CSO-g-CM-β-CD@AD-PTX) micelle was successfully prepared in water through sonication. The formed molecules were characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance (NMR) spectroscopy, two-dimensional NMR, elemental analysis, and liquid chromatography-mass spectrometry, while the correspondent micelles were characterized by dynamic light scattering and transmission electron microscopy. We showed that the macromolecular micelle contained a spherical core-shell structure with a diameter of 197.1 ± 3.3 nm and zeta potential of -19.1 ± 4.3 mV. The CSO-g-CM-β-CD@AD-PTX micelle exhibited a high drug-loading efficacy up to 31.3%, as well as a critical micelle concentration of 3.4 × 10-7 M, which indicated good stability. Additionally, the in vitro release profile of the CSO-g-CM-β-CD@AD-PTX micelle demonstrated a long-term release pattern, 63.1% of AD-PTX was released from the micelle during a 30-day period. Moreover, the CSO-g-CM-β-CD@AD-PTX micelle displayed cytotoxicity at a sub-μM scale similar to PTX in U87 MG cells, and CSO-g-CM-β-CD exhibited a good safety profile by not manifesting significant toxicity at concentrations up to 100 μM. These results indicated that β-CD-based inclusion complexation resulting in biodegradable self-assembled macromolecular micelles can be utilized as nanocarrier, and may provide a promising platform for drug delivery in the future medical applications. PMID:26964047

  14. Postprocedural CT for perivertebral cement leakage in percutaneous vertebroplasty is not necessary - results from VERTOS II

    Energy Technology Data Exchange (ETDEWEB)

    Venmans, Alexander; Klazen, Caroline A.; Rooij, Willem Jan van; Lohle, Paul N. [St. Elisabeth Ziekenhuis Tilburg, Department of Radiology, Tilburg (Netherlands); Vries, Jolanda de [St. Elisabeth Ziekenhuis Tilburg, Department of Medical Psychology, Tilburg (Netherlands); Mali, Willem P. [University Medical Centre Utrecht, Department of Radiology, Utrecht (Netherlands)

    2011-01-15

    During percutaneous vertebroplasty (PV), perivertebral cement leakage frequently occurs. There is some concern that cement deposits may migrate towards the lungs via the veins during follow-up. We used baseline and follow-up computed tomography (CT) to assess the incidence and extend of late cement migration in a large consecutive patient cohort. VERTOS II is a prospective multicenter randomized controlled trial comparing PV with conservative therapy for osteoporotic vertebral compression fractures (OVCFs). Patients assigned to PV had baseline postprocedural CT scans of the treated vertebral bodies. After a mean follow-up of 22 months, 54 of 78 patients (69%) had follow-up CT. CT scans were analyzed and compared for perivertebral venous, discal, and soft tissue leakage. Perivertebral cement leakage occurred in 64 of 80 treated vertebrae (80%; 95% CI, 70% to 87%). All patients remained asymptomatic. Perivertebral venous leakage was present in 56 vertebrae (88%), mostly in the anterior external venous plexus (46 of 56, 82%). Discal leakage occurred in 22 of 64 vertebrae (34%) and soft tissue leakage in two of 64 (4%). Mean injected cement volume in vertebrae with leakage was higher (4.5 versus 3.7 cm{sup 3}, p = 0.04). Follow-up CT scan showed unchanged perivertebral cement leakages without late cement migration. Perivertebral cement leaks during PV for OVCFs occurred frequently in the VERTOS II trial. Cement leakage occurred more frequently with higher injected volumes. However, all patients remained asymptomatic, and late cement migration during follow-up did not occur. Standard postprocedural CT of the treated vertebral body in PV is not necessary. (orig.)

  15. Quantification of marginal leakage area of aesthetic restorations systems used in indirect inlays

    Directory of Open Access Journals (Sweden)

    Gleidson Rocha Arouca

    2011-01-01

    Full Text Available Introduction and objective: Marginal leakage of inlays restorations is a key issue for dentists, because of the damaging consequences that its intensity may cause to the tooth, periodontium, and longevity of restoration. The aim of this study was to assess the cervical marginal leakage of two composite systems and a pressed ceramic, through area calculation associated with the longest distance between the restoration and preparation cervical edges. Material and methods: Based on a metal pattern model with MOD inlay preparation, 15 type IV dental stone casts were obtained and randomly distributed into three groups (n = 5 as follows: Empress Group, Sinfony Group, Z350 Group. After restorations had been made, each one was positioned on the pattern model. Following, their middle and distal faces were photographed in order to analyze marginal cervical leakage through a computer software program. Results: Cervical marginal leakage area: there was statistically significant difference among the three groups (P < 0.05. Empress Group presented the highest values, followed by Sinfony and Z350 groups. Empress and Sinfony groups showed, respectively, a leakage area of 280% and 110% higher than Z350 group. Longest distance between restoration and preparation edges: Statistically significant differences were not observed between Empress and Sinfony groups; however, they showed statistically significant (P < 0.05 differences when compared to Z350 group (215% and 120% greater leakage than Z350 group, respectively. Conclusion: Considering the cervical marginal leakage area calculation and the longest distance between restoration and preparation edges, marginal leakage was smaller in Z350 group followed by Sinfony and Empress groups. In the analysis of cervical marginal leakage, all groups were clinically acceptable.

  16. Nitrogen limitation in natural populations of cyanobacteria (Spirulina and Oscillatoria spp.) and its effect on macromolecular synthesis

    International Nuclear Information System (INIS)

    Natural populations of the cyanobacteria Spirulina species and Oscillatoria species obtained from Israeli fish ponds were limited in growth by nitrogen availability in summer. Physiological indicators for nitrogen limitation, such as phycocyanin, chlorophyll a, and carbohydrate content, did not show clear evidence for nitrogen limited growth, since these organisms are capable of vertical migration from and to the nitrogen-rich bottom. By means of 14C labeling of the cells under simulated pond conditions followed by cell fractionation into macromolecular compounds, it was found that carbohydrates synthesized at the lighted surface were partially utilized for dark protein synthesis at the bottom of these ponds

  17. Modeling the leakage of LCD displays with local backlight for quality assessment

    DEFF Research Database (Denmark)

    Mantel, Claire; Korhonen, Jari; Pedersen, Jesper M.;

    2014-01-01

    The recent technique of local backlight dimming has a significant impact on the quality of images displayed with a LCD screen with LED local dimming. Therefore it represents a necessary step in the quality assessment chain, independently from the other processes applied to images. This paper...... on videos displayed on LCD TV with local backlight dimming viewed from a 0° and 15° angles. The subjective results are then compared objective data using different leakage models: constant over the whole display or horizontally varying and three leakage factor (no leakage, measured at 0° and 15...

  18. Efficient quantum dialogue using entangled states and entanglement swapping without information leakage

    Science.gov (United States)

    Wang, He; Zhang, Yu Qing; Liu, Xue Feng; Hu, Yu Pu

    2016-06-01

    We propose a novel quantum dialogue protocol by using the generalized Bell states and entanglement swapping. In the protocol, a sequence of ordered two-qutrit entangled states acts as quantum information channel for exchanging secret messages directly and simultaneously. Besides, a secret key string is shared between the communicants to overcome information leakage. Different from those previous information leakage-resistant quantum dialogue protocols, the particles, composed of one of each pair of entangled states, are transmitted only one time in the proposed protocol. Security analysis shows that our protocol can overcome information leakage and resist several well-known attacks. Moreover, the efficiency of our scheme is acceptable.

  19. Highly Reliable Transformerless Photovoltaic Inverters With Leakage Current and Pulsating Power Elimination

    DEFF Research Database (Denmark)

    Tang, Yi; Yao, Wenli; Loh, Poh Chiang;

    2016-01-01

    This paper presents a transformerless inverter topology, which is capable of simultaneously solving leakage current and pulsating power issues in grid-connected photovoltaic (PV) systems. Without adding any additional components to the system, the leakage current caused by the PV-to-ground...... parasitic capacitance can be bypassed by introducing a common-mode (CM) conducting path to the inverter. The resulting ground leakage current is therefore well controlled to be below the regulation limit. Furthermore, the proposed inverter can also eliminate the well-known double-line-frequency pulsating...... excellent performance of the proposed PV inverter....

  20. Cumulative Impacts of Energy and Climate Change Policies on Carbon Leakage

    Energy Technology Data Exchange (ETDEWEB)

    Varma, A.; Milnes, R.; Miller, K.; Williams, E. [AEA Technology plc, London (United Kingdom); De Bruyn, S.; Brinke, L. [CE Delft, Delft (Netherlands)

    2012-02-15

    Carbon leakage occurs when climate change policy aimed at reducing carbon dioxide emissions in one country leads to an increase in carbon dioxide emissions in a country that is not bound by these policies. Given that climate change is a global issue, carbon leakage impacts upon the effectiveness of climate change policies. This independent study examines the cumulative impact of climate change policies on carbon leakage. The report brings together findings and analysis from a wide range of primary literature in this area and where possible, conclusions relevant to the UK are drawn.