WorldWideScience

Sample records for based molecular replacement

  1. MrGrid: a portable grid based molecular replacement pipeline.

    Science.gov (United States)

    Schmidberger, Jason W; Bate, Mark A; Reboul, Cyril F; Androulakis, Steve G; Phan, Jennifer M N; Whisstock, James C; Goscinski, Wojtek J; Abramson, David; Buckle, Ashley M

    2010-04-06

    The crystallographic determination of protein structures can be computationally demanding and for difficult cases can benefit from user-friendly interfaces to high-performance computing resources. Molecular replacement (MR) is a popular protein crystallographic technique that exploits the structural similarity between proteins that share some sequence similarity. But the need to trial permutations of search models, space group symmetries and other parameters makes MR time- and labour-intensive. However, MR calculations are embarrassingly parallel and thus ideally suited to distributed computing. In order to address this problem we have developed MrGrid, web-based software that allows multiple MR calculations to be executed across a grid of networked computers, allowing high-throughput MR. MrGrid is a portable web based application written in Java/JSP and Ruby, and taking advantage of Apple Xgrid technology. Designed to interface with a user defined Xgrid resource the package manages the distribution of multiple MR runs to the available nodes on the Xgrid. We evaluated MrGrid using 10 different protein test cases on a network of 13 computers, and achieved an average speed up factor of 5.69. MrGrid enables the user to retrieve and manage the results of tens to hundreds of MR calculations quickly and via a single web interface, as well as broadening the range of strategies that can be attempted. This high-throughput approach allows parameter sweeps to be performed in parallel, improving the chances of MR success.

  2. MrGrid: a portable grid based molecular replacement pipeline.

    Directory of Open Access Journals (Sweden)

    Jason W Schmidberger

    Full Text Available BACKGROUND: The crystallographic determination of protein structures can be computationally demanding and for difficult cases can benefit from user-friendly interfaces to high-performance computing resources. Molecular replacement (MR is a popular protein crystallographic technique that exploits the structural similarity between proteins that share some sequence similarity. But the need to trial permutations of search models, space group symmetries and other parameters makes MR time- and labour-intensive. However, MR calculations are embarrassingly parallel and thus ideally suited to distributed computing. In order to address this problem we have developed MrGrid, web-based software that allows multiple MR calculations to be executed across a grid of networked computers, allowing high-throughput MR. METHODOLOGY/PRINCIPAL FINDINGS: MrGrid is a portable web based application written in Java/JSP and Ruby, and taking advantage of Apple Xgrid technology. Designed to interface with a user defined Xgrid resource the package manages the distribution of multiple MR runs to the available nodes on the Xgrid. We evaluated MrGrid using 10 different protein test cases on a network of 13 computers, and achieved an average speed up factor of 5.69. CONCLUSIONS: MrGrid enables the user to retrieve and manage the results of tens to hundreds of MR calculations quickly and via a single web interface, as well as broadening the range of strategies that can be attempted. This high-throughput approach allows parameter sweeps to be performed in parallel, improving the chances of MR success.

  3. Initiating Heavy-atom Based Phasing by Multi-Dimensional Molecular Replacement

    DEFF Research Database (Denmark)

    Pedersen, Bjørn Panyella; Gourdon, Pontus; Liu, Xiangyu

    2014-01-01

    -based approaches, which however may fail when only poorly diffracting derivative crystals are available, as often the case for e.g. membrane proteins. Here we present an approach for heavy atom site identification based on a Molecular Replacement Parameter Matrix (MRPM) search. It involves an n-dimensional search...... to test a wide spectrum of molecular replacement parameters, such as clusters of different conformations. The result is scored by the ability to identify heavy-atom positions, from anomalous difference Fourier maps, that allow meaningful phases to be determined. The strategy was successfully applied...... but correct molecular replacement solutions with maximum contrast to prime experimental phasing efforts....

  4. Initiating heavy-atom-based phasing by multi-dimensional molecular replacement.

    Science.gov (United States)

    Pedersen, Bjørn Panyella; Gourdon, Pontus; Liu, Xiangyu; Karlsen, Jesper Lykkegaard; Nissen, Poul

    2016-03-01

    To obtain an electron-density map from a macromolecular crystal the phase problem needs to be solved, which often involves the use of heavy-atom derivative crystals and concomitant heavy-atom substructure determination. This is typically performed by dual-space methods, direct methods or Patterson-based approaches, which however may fail when only poorly diffracting derivative crystals are available. This is often the case for, for example, membrane proteins. Here, an approach for heavy-atom site identification based on a molecular-replacement parameter matrix (MRPM) is presented. It involves an n-dimensional search to test a wide spectrum of molecular-replacement parameters, such as different data sets and search models with different conformations. Results are scored by the ability to identify heavy-atom positions from anomalous difference Fourier maps. The strategy was successfully applied in the determination of a membrane-protein structure, the copper-transporting P-type ATPase CopA, when other methods had failed to determine the heavy-atom substructure. MRPM is well suited to proteins undergoing large conformational changes where multiple search models should be considered, and it enables the identification of weak but correct molecular-replacement solutions with maximum contrast to prime experimental phasing efforts.

  5. Initiating Heavy-atom Based Phasing by Multi-Dimensional Molecular Replacement

    DEFF Research Database (Denmark)

    Pedersen, Bjørn Panyella; Gourdon, Pontus Emanuel; Liu, Xiangyu

    2014-01-01

    in the determination of a membrane protein structure, the CopA Cu+-ATPase, when other methods had failed to resolve the heavy atom substructure. MRPM is particularly suited for proteins undergoing large conformational changes where multiple search models should be generated, and it enables the identification of weak...... but correct molecular replacement solutions with maximum contrast to prime experimental phasing efforts....

  6. Molecular replacement then and now

    International Nuclear Information System (INIS)

    Scapin, Giovanna

    2013-01-01

    A brief overview, with examples, of the evolution of molecular-replacement methods and models over the past few years is presented. The ‘phase problem’ in crystallography results from the inability to directly measure the phases of individual diffracted X-ray waves. While intensities are directly measured during data collection, phases must be obtained by other means. Several phasing methods are available (MIR, SAR, MAD, SAD and MR) and they all rely on the premise that phase information can be obtained if the positions of marker atoms in the unknown crystal structure are known. This paper is dedicated to the most popular phasing method, molecular replacement (MR), and represents a personal overview of the development, use and requirements of the methodology. The first description of noncrystallographic symmetry as a tool for structure determination was explained by Rossmann and Blow [Rossmann & Blow (1962 ▶), Acta Cryst.15, 24–31]. The term ‘molecular replacement’ was introduced as the name of a book in which the early papers were collected and briefly reviewed [Rossmann (1972 ▶), The Molecular Replacement Method. New York: Gordon & Breach]. Several programs have evolved from the original concept to allow faster and more sophisticated searches, including six-dimensional searches and brute-force approaches. While careful selection of the resolution range for the search and the quality of the data will greatly influence the outcome, the correct choice of the search model is probably still the main criterion to guarantee success in solving a structure using MR. Two of the main parameters used to define the ‘best’ search model are sequence identity (25% or more) and structural similarity. Another parameter that may often be undervalued is the quality of the probe: there is clearly a relationship between the quality and the correctness of the chosen probe and its usefulness as a search model. Efforts should be made by all structural biologists to

  7. Phaser.MRage: automated molecular replacement

    International Nuclear Information System (INIS)

    Bunkóczi, Gábor; Echols, Nathaniel; McCoy, Airlie J.; Oeffner, Robert D.; Adams, Paul D.; Read, Randy J.

    2013-01-01

    The functionality of the molecular-replacement pipeline phaser.MRage is introduced and illustrated with examples. Phaser.MRage is a molecular-replacement automation framework that implements a full model-generation workflow and provides several layers of model exploration to the user. It is designed to handle a large number of models and can distribute calculations efficiently onto parallel hardware. In addition, phaser.MRage can identify correct solutions and use this information to accelerate the search. Firstly, it can quickly score all alternative models of a component once a correct solution has been found. Secondly, it can perform extensive analysis of identified solutions to find protein assemblies and can employ assembled models for subsequent searches. Thirdly, it is able to use a priori assembly information (derived from, for example, homologues) to speculatively place and score molecules, thereby customizing the search procedure to a certain class of protein molecule (for example, antibodies) and incorporating additional biological information into molecular replacement

  8. COMO: a program for combined molecular replacement.

    Science.gov (United States)

    Jogl, G; Tao, X; Xu, Y; Tong, L

    2001-08-01

    The combined molecular-replacement protocol uses a limited six-dimensional search to solve a structure by the molecular-replacement method, with the sampling of the rotational degrees of freedom guided by the rotation function. This protocol therefore automatically combines the information on the rotational and translational parameters of the search model. The combined molecular-replacement protocol has been implemented in a new computer program, COMO. The calculation of the Patterson correlation translation function has been optimized to improve its speed performance. A packing check is implemented that automatically removes impossible solutions and thereby increases the signal in the calculation. A family of atomic models can be used as the search model; the program will automatically select the model that gives the best result. The command interface is well organized and requires the definition of only a few critical parameters by the user. In addition, a graphical user interface has been constructed for the program. The program has been used to solve several difficult molecular-replacement problems. A case is presented where the program automatically determined the orientation and position of five copies of a search model in a high-symmetry space group.

  9. BALBES: a molecular-replacement pipeline

    International Nuclear Information System (INIS)

    Long, Fei; Vagin, Alexei A.; Young, Paul; Murshudov, Garib N.

    2008-01-01

    The fully automated pipeline, BALBES, integrates a redesigned hierarchical database of protein structures with their domains and multimeric organization, and solves molecular-replacement problems using only input X-ray and sequence data. The number of macromolecular structures solved and deposited in the Protein Data Bank (PDB) is higher than 40 000. Using this information in macromolecular crystallography (MX) should in principle increase the efficiency of MX structure solution. This paper describes a molecular-replacement pipeline, BALBES, that makes extensive use of this repository. It uses a reorganized database taken from the PDB with multimeric as well as domain organization. A system manager written in Python controls the workflow of the process. Testing the current version of the pipeline using entries from the PDB has shown that this approach has huge potential and that around 75% of structures can be solved automatically without user intervention

  10. Phaser.MRage: automated molecular replacement.

    Science.gov (United States)

    Bunkóczi, Gábor; Echols, Nathaniel; McCoy, Airlie J; Oeffner, Robert D; Adams, Paul D; Read, Randy J

    2013-11-01

    Phaser.MRage is a molecular-replacement automation framework that implements a full model-generation workflow and provides several layers of model exploration to the user. It is designed to handle a large number of models and can distribute calculations efficiently onto parallel hardware. In addition, phaser.MRage can identify correct solutions and use this information to accelerate the search. Firstly, it can quickly score all alternative models of a component once a correct solution has been found. Secondly, it can perform extensive analysis of identified solutions to find protein assemblies and can employ assembled models for subsequent searches. Thirdly, it is able to use a priori assembly information (derived from, for example, homologues) to speculatively place and score molecules, thereby customizing the search procedure to a certain class of protein molecule (for example, antibodies) and incorporating additional biological information into molecular replacement.

  11. BALBES: a molecular-replacement pipeline

    OpenAIRE

    Long, Fei; Vagin, Alexei A.; Young, Paul; Murshudov, Garib N.

    2007-01-01

    The number of macromolecular structures solved and deposited in the Protein Data Bank (PDB) is higher than 40?000. Using this information in macromolecular crystallo?graphy (MX) should in principle increase the efficiency of MX structure solution. This paper describes a molecular-replacement pipeline, BALBES, that makes extensive use of this repository. It uses a reorganized database taken from the PDB with multimeric as well as domain organization. A system manager written in Python controls...

  12. BALBES: a molecular-replacement pipeline.

    Science.gov (United States)

    Long, Fei; Vagin, Alexei A; Young, Paul; Murshudov, Garib N

    2008-01-01

    The number of macromolecular structures solved and deposited in the Protein Data Bank (PDB) is higher than 40 000. Using this information in macromolecular crystallography (MX) should in principle increase the efficiency of MX structure solution. This paper describes a molecular-replacement pipeline, BALBES, that makes extensive use of this repository. It uses a reorganized database taken from the PDB with multimeric as well as domain organization. A system manager written in Python controls the workflow of the process. Testing the current version of the pipeline using entries from the PDB has shown that this approach has huge potential and that around 75% of structures can be solved automatically without user intervention.

  13. ARP/wARP and molecular replacement: the next generation

    International Nuclear Information System (INIS)

    Cohen, Serge X.; Ben Jelloul, Marouane; Long, Fei; Vagin, Alexei; Knipscheer, Puck; Lebbink, Joyce; Sixma, Titia K.; Lamzin, Victor S.; Murshudov, Garib N.; Perrakis, Anastassis

    2008-01-01

    A systematic test shows how ARP/wARP deals with automated model building for structures that have been solved by molecular replacement. A description of protocols in the flex-wARP control system and studies of two specific cases are also presented. Automatic iterative model (re-)building, as implemented in ARP/wARP and its new control system flex-wARP, is particularly well suited to follow structure solution by molecular replacement. More than 100 molecular-replacement solutions automatically solved by the BALBES software were submitted to three standard protocols in flex-wARP and the results were compared with final models from the PDB. Standard metrics were gathered in a systematic way and enabled the drawing of statistical conclusions on the advantages of each protocol. Based on this analysis, an empirical estimator was proposed that predicts how good the final model produced by flex-wARP is likely to be based on the experimental data and the quality of the molecular-replacement solution. To introduce the differences between the three flex-wARP protocols (keeping the complete search model, converting it to atomic coordinates but ignoring atom identities or using the electron-density map calculated from the molecular-replacement solution), two examples are also discussed in detail, focusing on the evolution of the models during iterative rebuilding. This highlights the diversity of paths that the flex-wARP control system can employ to reach a nearly complete and accurate model while actually starting from the same initial information

  14. MrBUMP: an automated pipeline for molecular replacement

    OpenAIRE

    Keegan, Ronan M.; Winn, Martyn D.

    2007-01-01

    A novel automation pipeline for macromolecular structure solution by molecular replacement is described. There is a special emphasis on the discovery and preparation of a large number of search models, all of which can be passed to the core molecular-replacement programs. For routine molecular-replacement problems, the pipeline automates what a crystallographer might do and its value is simply one of convenience. For more difficult cases, the pipeline aims to discover the particular template ...

  15. Applications of molecular replacement to G protein-coupled receptors

    Energy Technology Data Exchange (ETDEWEB)

    Kruse, Andrew C.; Manglik, Aashish; Kobilka, Brian K., E-mail: kobilka@stanford.edu [Stanford University, 279 Campus Drive, Stanford, CA 94305 (United States); Weis, William I., E-mail: kobilka@stanford.edu [Stanford University, 279 Campus Drive, Stanford, CA 94305 (United States); Stanford University, Fairchild Building, Stanford, CA 94305 (United States)

    2013-11-01

    The use of molecular replacement in solving the structures of G protein-coupled receptors is discussed, with specific examples being described in detail. G protein-coupled receptors (GPCRs) are a large class of integral membrane proteins involved in regulating virtually every aspect of human physiology. Despite their profound importance in human health and disease, structural information regarding GPCRs has been extremely limited until recently. With the advent of a variety of new biochemical and crystallographic techniques, the structural biology of GPCRs has advanced rapidly, offering key molecular insights into GPCR activation and signal transduction. To date, almost all GPCR structures have been solved using molecular-replacement techniques. Here, the unique aspects of molecular replacement as applied to individual GPCRs and to signaling complexes of these important proteins are discussed.

  16. On the application of the expected log-likelihood gain to decision making in molecular replacement.

    Science.gov (United States)

    Oeffner, Robert D; Afonine, Pavel V; Millán, Claudia; Sammito, Massimo; Usón, Isabel; Read, Randy J; McCoy, Airlie J

    2018-04-01

    Molecular-replacement phasing of macromolecular crystal structures is often fast, but if a molecular-replacement solution is not immediately obtained the crystallographer must judge whether to pursue molecular replacement or to attempt experimental phasing as the quickest path to structure solution. The introduction of the expected log-likelihood gain [eLLG; McCoy et al. (2017), Proc. Natl Acad. Sci. USA, 114, 3637-3641] has given the crystallographer a powerful new tool to aid in making this decision. The eLLG is the log-likelihood gain on intensity [LLGI; Read & McCoy (2016), Acta Cryst. D72, 375-387] expected from a correctly placed model. It is calculated as a sum over the reflections of a function dependent on the fraction of the scattering for which the model accounts, the estimated model coordinate error and the measurement errors in the data. It is shown how the eLLG may be used to answer the question `can I solve my structure by molecular replacement?'. However, this is only the most obvious of the applications of the eLLG. It is also discussed how the eLLG may be used to determine the search order and minimal data requirements for obtaining a molecular-replacement solution using a given model, and for decision making in fragment-based molecular replacement, single-atom molecular replacement and likelihood-guided model pruning.

  17. MrBUMP: an automated pipeline for molecular replacement.

    Science.gov (United States)

    Keegan, Ronan M; Winn, Martyn D

    2008-01-01

    A novel automation pipeline for macromolecular structure solution by molecular replacement is described. There is a special emphasis on the discovery and preparation of a large number of search models, all of which can be passed to the core molecular-replacement programs. For routine molecular-replacement problems, the pipeline automates what a crystallographer might do and its value is simply one of convenience. For more difficult cases, the pipeline aims to discover the particular template structure and model edits required to produce a viable search model and may succeed in finding an efficacious combination that would be missed otherwise. An overview of MrBUMP is given and some recent additions to its functionality are highlighted.

  18. The importance of alignment accuracy for molecular replacement.

    Science.gov (United States)

    Schwarzenbacher, Robert; Godzik, Adam; Grzechnik, Slawomir K; Jaroszewski, Lukasz

    2004-07-01

    Many crystallographic protein structures are being determined using molecular replacement (MR), a model-based phasing method that has become increasingly important with the steady growth of the PDB. While there are several highly automated software packages for MR, the methods for preparing optimal search models for MR are relatively unexplored. Recent advances in sequence-comparison methods allow the detection of more distantly related homologs and more accurate alignment of their sequences. It was investigated whether simple homology models (without modeling of unaligned regions) based on alignments from these improved methods are able to increase the potential of MR. 27 crystal structures were determined using a highly parallelized MR pipeline that facilitates all steps including homology detection, model preparation, MR searches, automated refinement and rebuilding. Several types of search models prepared with standard sequence-sequence alignment (BLAST) and more accurate profile-sequence and profile-profile methods (PSI-BLAST, FFAS) were compared in MR trials. The analysis shows that models based on more accurate alignments have a higher success rate in cases where the unknown structure and the search model share less than 35% sequence identity. It is concluded that by using different types of simple models based on accurate alignments, the success rate of MR can be significantly increased.

  19. Solving structures of protein complexes by molecular replacement with Phaser

    International Nuclear Information System (INIS)

    McCoy, Airlie J.

    2006-01-01

    Four case studies in using maximum-likelihood molecular replacement, as implemented in the program Phaser, to solve structures of protein complexes are described. Molecular replacement (MR) generally becomes more difficult as the number of components in the asymmetric unit requiring separate MR models (i.e. the dimensionality of the search) increases. When the proportion of the total scattering contributed by each search component is small, the signal in the search for each component in isolation is weak or non-existent. Maximum-likelihood MR functions enable complex asymmetric units to be built up from individual components with a ‘tree search with pruning’ approach. This method, as implemented in the automated search procedure of the program Phaser, has been very successful in solving many previously intractable MR problems. However, there are a number of cases in which the automated search procedure of Phaser is suboptimal or encounters difficulties. These include cases where there are a large number of copies of the same component in the asymmetric unit or where the components of the asymmetric unit have greatly varying B factors. Two case studies are presented to illustrate how Phaser can be used to best advantage in the standard ‘automated MR’ mode and two case studies are used to show how to modify the automated search strategy for problematic cases

  20. SCEDS: protein fragments for molecular replacement in Phaser

    International Nuclear Information System (INIS)

    McCoy, Airlie J.; Nicholls, Robert A.; Schneider, Thomas R.

    2013-01-01

    Protein fragments suitable for use in molecular replacement can be generated by normal-mode perturbation, analysis of the difference distance matrix of the original versus normal-mode perturbed structures, and SCEDS, a score that measures the sphericity, continuity, equality and density of the resulting fragments. A method is described for generating protein fragments suitable for use as molecular-replacement (MR) template models. The template model for a protein suspected to undergo a conformational change is perturbed along combinations of low-frequency normal modes of the elastic network model. The unperturbed structure is then compared with each perturbed structure in turn and the structurally invariant regions are identified by analysing the difference distance matrix. These fragments are scored with SCEDS, which is a combined measure of the sphericity of the fragments, the continuity of the fragments with respect to the polypeptide chain, the equality in number of atoms in the fragments and the density of C α atoms in the triaxial ellipsoid of the fragment extents. The fragment divisions with the highest SCEDS are then used as separate template models for MR. Test cases show that where the protein contains fragments that undergo a change in juxtaposition between template model and target, SCEDS can identify fragments that lead to a lower R factor after ten cycles of all-atom refinement with REFMAC5 than the original template structure. The method has been implemented in the software Phaser

  1. SCEDS: protein fragments for molecular replacement in Phaser

    Energy Technology Data Exchange (ETDEWEB)

    McCoy, Airlie J., E-mail: ajm201@cam.ac.uk [University of Cambridge, Hills Road, Cambridge CB2 0XY (United Kingdom); Nicholls, Robert A. [MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH (United Kingdom); Schneider, Thomas R. [Hamburg Unit c/o DESY, Notkestrasse 85, 22603 Hamburg (Germany); University of Cambridge, Hills Road, Cambridge CB2 0XY (United Kingdom)

    2013-11-01

    Protein fragments suitable for use in molecular replacement can be generated by normal-mode perturbation, analysis of the difference distance matrix of the original versus normal-mode perturbed structures, and SCEDS, a score that measures the sphericity, continuity, equality and density of the resulting fragments. A method is described for generating protein fragments suitable for use as molecular-replacement (MR) template models. The template model for a protein suspected to undergo a conformational change is perturbed along combinations of low-frequency normal modes of the elastic network model. The unperturbed structure is then compared with each perturbed structure in turn and the structurally invariant regions are identified by analysing the difference distance matrix. These fragments are scored with SCEDS, which is a combined measure of the sphericity of the fragments, the continuity of the fragments with respect to the polypeptide chain, the equality in number of atoms in the fragments and the density of C{sup α} atoms in the triaxial ellipsoid of the fragment extents. The fragment divisions with the highest SCEDS are then used as separate template models for MR. Test cases show that where the protein contains fragments that undergo a change in juxtaposition between template model and target, SCEDS can identify fragments that lead to a lower R factor after ten cycles of all-atom refinement with REFMAC5 than the original template structure. The method has been implemented in the software Phaser.

  2. Improved estimates of coordinate error for molecular replacement

    International Nuclear Information System (INIS)

    Oeffner, Robert D.; Bunkóczi, Gábor; McCoy, Airlie J.; Read, Randy J.

    2013-01-01

    A function for estimating the effective root-mean-square deviation in coordinates between two proteins has been developed that depends on both the sequence identity and the size of the protein and is optimized for use with molecular replacement in Phaser. A top peak translation-function Z-score of over 8 is found to be a reliable metric of when molecular replacement has succeeded. The estimate of the root-mean-square deviation (r.m.s.d.) in coordinates between the model and the target is an essential parameter for calibrating likelihood functions for molecular replacement (MR). Good estimates of the r.m.s.d. lead to good estimates of the variance term in the likelihood functions, which increases signal to noise and hence success rates in the MR search. Phaser has hitherto used an estimate of the r.m.s.d. that only depends on the sequence identity between the model and target and which was not optimized for the MR likelihood functions. Variance-refinement functionality was added to Phaser to enable determination of the effective r.m.s.d. that optimized the log-likelihood gain (LLG) for a correct MR solution. Variance refinement was subsequently performed on a database of over 21 000 MR problems that sampled a range of sequence identities, protein sizes and protein fold classes. Success was monitored using the translation-function Z-score (TFZ), where a TFZ of 8 or over for the top peak was found to be a reliable indicator that MR had succeeded for these cases with one molecule in the asymmetric unit. Good estimates of the r.m.s.d. are correlated with the sequence identity and the protein size. A new estimate of the r.m.s.d. that uses these two parameters in a function optimized to fit the mean of the refined variance is implemented in Phaser and improves MR outcomes. Perturbing the initial estimate of the r.m.s.d. from the mean of the distribution in steps of standard deviations of the distribution further increases MR success rates

  3. Functional and molecular neuroimaging of menopause and hormone replacement therapy

    Directory of Open Access Journals (Sweden)

    Erika eComasco

    2014-12-01

    Full Text Available The level of gonadal hormones to which the female brain is exposed considerably changes across the menopausal transition, which in turn, is likely to be of great relevance for neurodegenerative diseases and psychiatric disorders. However, the neurobiological consequences of these hormone fluctuations and of hormone replacement therapy in the menopause have only begun to be understood. This review summarizes the findings of thirty-four studies of human brain function, including functional magnetic resonance imaging, positron and single-photon computed emission tomography studies, in peri- and postmenopausal women treated with estrogen, or estrogen-progestagen replacement therapy. Seven studies using gonadotropin-releasing hormone agonist intervention as a model of hormonal withdrawal are also included. Cognitive paradigms are employed by the majority of studies evaluating the effect of unopposed estrogen or estrogen-progestagen treatment on peri- and postmenopausal women’s brain. In randomized-controlled trials, estrogen treatment enhances activation of fronto-cingulate regions during cognitive functioning, though in many cases no difference in cognitive performance was present. Progestagens seems to counteract the effects of estrogens. Findings on cognitive functioning during acute ovarian hormone withdrawal suggest a decrease in activation of the inferior frontal gyrus, thus essentially corroborating the findings in postmenopausal women. Studies of the cholinergic and serotonergic systems indicate these systems as biological mediators of hormonal influences on the brain. More, hormonal replacement appears to increase cerebral blood flow in cortical regions. On the other hand, studies on emotion processing in postmenopausal women are lacking. These results call for well-powered randomized-controlled multi-modal prospective neuroimaging studies as well as investigation on the related molecular mechanisms of effects of menopausal hormonal

  4. Functional and molecular neuroimaging of menopause and hormone replacement therapy

    DEFF Research Database (Denmark)

    Comasco, Erika; Frøkjær, Vibe; Sundström-Poromaa, Inger

    2014-01-01

    The level of gonadal hormones to which the female brain is exposed considerably changes across the menopausal transition, which in turn, is likely to be of great relevance for neurodegenerative diseases and psychiatric disorders. However, the neurobiological consequences of these hormone fluctuat......The level of gonadal hormones to which the female brain is exposed considerably changes across the menopausal transition, which in turn, is likely to be of great relevance for neurodegenerative diseases and psychiatric disorders. However, the neurobiological consequences of these hormone...... fluctuations and of hormone replacement therapy in the menopause have only begun to be understood. The present review summarizes the findings of thirty-five studies of human brain function, including functional magnetic resonance imaging, positron and single-photon computed emission tomography studies, in peri......-controlled multi-modal prospective neuroimaging studies as well as investigation on the related molecular mechanisms of effects of menopausal hormonal variations on the brain....

  5. Equilibrium simulations of proteins using molecular fragment replacement and NMR chemical shifts.

    Science.gov (United States)

    Boomsma, Wouter; Tian, Pengfei; Frellsen, Jes; Ferkinghoff-Borg, Jesper; Hamelryck, Thomas; Lindorff-Larsen, Kresten; Vendruscolo, Michele

    2014-09-23

    Methods of protein structure determination based on NMR chemical shifts are becoming increasingly common. The most widely used approaches adopt the molecular fragment replacement strategy, in which structural fragments are repeatedly reassembled into different complete conformations in molecular simulations. Although these approaches are effective in generating individual structures consistent with the chemical shift data, they do not enable the sampling of the conformational space of proteins with correct statistical weights. Here, we present a method of molecular fragment replacement that makes it possible to perform equilibrium simulations of proteins, and hence to determine their free energy landscapes. This strategy is based on the encoding of the chemical shift information in a probabilistic model in Markov chain Monte Carlo simulations. First, we demonstrate that with this approach it is possible to fold proteins to their native states starting from extended structures. Second, we show that the method satisfies the detailed balance condition and hence it can be used to carry out an equilibrium sampling from the Boltzmann distribution corresponding to the force field used in the simulations. Third, by comparing the results of simulations carried out with and without chemical shift restraints we describe quantitatively the effects that these restraints have on the free energy landscapes of proteins. Taken together, these results demonstrate that the molecular fragment replacement strategy can be used in combination with chemical shift information to characterize not only the native structures of proteins but also their conformational fluctuations.

  6. Equilibrium simulations of proteins using molecular fragment replacement and NMR chemical shifts

    DEFF Research Database (Denmark)

    Boomsma, Wouter; Tian, Pengfei; Frellsen, J.

    2014-01-01

    Significance Chemical shifts are the most fundamental parameters measured in nuclear magnetic resonance spectroscopy. Since these parameters are exquisitely sensitive to the local atomic environment, they can provide detailed information about the three-dimensional structures of proteins. It has...... recently been shown that using such information directly as input in molecular simulations based on the molecular fragment replacement strategy can help the process of protein structure determination. Here, we show how to implement this strategy to determine not only the structures of proteins but also...

  7. Advances in molecular-replacement procedures: the REVAN pipeline.

    Science.gov (United States)

    Carrozzini, Benedetta; Cascarano, Giovanni Luca; Giacovazzo, Carmelo; Mazzone, Annamaria

    2015-09-01

    The REVAN pipeline aiming at the solution of protein structures via molecular replacement (MR) has been assembled. It is the successor to REVA, a pipeline that is particularly efficient when the sequence identity (SI) between the target and the model is greater than 0.30. The REVAN and REVA procedures coincide when the SI is >0.30, but differ substantially in worse conditions. To treat these cases, REVAN combines a variety of programs and algorithms (REMO09, REFMAC, DM, DSR, VLD, free lunch, Coot, Buccaneer and phenix.autobuild). The MR model, suitably rotated and positioned, is first refined by a standard REFMAC refinement procedure, and the corresponding electron density is then submitted to cycles of DM-VLD-REFMAC. The next REFMAC applications exploit the better electron densities obtained at the end of the VLD-EDM sections (a procedure called vector refinement). In order to make the model more similar to the target, the model is submitted to mutations, in which Coot plays a basic role, and it is then cyclically resubmitted to REFMAC-EDM-VLD cycles. The phases thus obtained are submitted to free lunch and allow most of the test structures studied by DiMaio et al. [(2011), Nature (London), 473, 540-543] to be solved without using energy-guided programs.

  8. Model morphing and sequence assignment after molecular replacement

    International Nuclear Information System (INIS)

    Terwilliger, Thomas C.; Read, Randy J.; Adams, Paul D.; Brunger, Axel T.; Afonine, Pavel V.; Hung, Li-Wei

    2013-01-01

    A procedure for model building is described that combines morphing a model to match a density map, trimming the morphed model and aligning the model to a sequence. A procedure termed ‘morphing’ for improving a model after it has been placed in the crystallographic cell by molecular replacement has recently been developed. Morphing consists of applying a smooth deformation to a model to make it match an electron-density map more closely. Morphing does not change the identities of the residues in the chain, only their coordinates. Consequently, if the true structure differs from the working model by containing different residues, these differences cannot be corrected by morphing. Here, a procedure that helps to address this limitation is described. The goal of the procedure is to obtain a relatively complete model that has accurate main-chain atomic positions and residues that are correctly assigned to the sequence. Residues in a morphed model that do not match the electron-density map are removed. Each segment of the resulting trimmed morphed model is then assigned to the sequence of the molecule using information about the connectivity of the chains from the working model and from connections that can be identified from the electron-density map. The procedure was tested by application to a recently determined structure at a resolution of 3.2 Å and was found to increase the number of correctly identified residues in this structure from the 88 obtained using phenix.resolve sequence assignment alone (Terwilliger, 2003 ▶) to 247 of a possible 359. Additionally, the procedure was tested by application to a series of templates with sequence identities to a target structure ranging between 7 and 36%. The mean fraction of correctly identified residues in these cases was increased from 33% using phenix.resolve sequence assignment to 47% using the current procedure. The procedure is simple to apply and is available in the Phenix software package

  9. Model morphing and sequence assignment after molecular replacement.

    Science.gov (United States)

    Terwilliger, Thomas C; Read, Randy J; Adams, Paul D; Brunger, Axel T; Afonine, Pavel V; Hung, Li-Wei

    2013-11-01

    A procedure termed `morphing' for improving a model after it has been placed in the crystallographic cell by molecular replacement has recently been developed. Morphing consists of applying a smooth deformation to a model to make it match an electron-density map more closely. Morphing does not change the identities of the residues in the chain, only their coordinates. Consequently, if the true structure differs from the working model by containing different residues, these differences cannot be corrected by morphing. Here, a procedure that helps to address this limitation is described. The goal of the procedure is to obtain a relatively complete model that has accurate main-chain atomic positions and residues that are correctly assigned to the sequence. Residues in a morphed model that do not match the electron-density map are removed. Each segment of the resulting trimmed morphed model is then assigned to the sequence of the molecule using information about the connectivity of the chains from the working model and from connections that can be identified from the electron-density map. The procedure was tested by application to a recently determined structure at a resolution of 3.2 Å and was found to increase the number of correctly identified residues in this structure from the 88 obtained using phenix.resolve sequence assignment alone (Terwilliger, 2003) to 247 of a possible 359. Additionally, the procedure was tested by application to a series of templates with sequence identities to a target structure ranging between 7 and 36%. The mean fraction of correctly identified residues in these cases was increased from 33% using phenix.resolve sequence assignment to 47% using the current procedure. The procedure is simple to apply and is available in the Phenix software package.

  10. Model morphing and sequence assignment after molecular replacement

    Energy Technology Data Exchange (ETDEWEB)

    Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Los Alamos National Laboratory, Mail Stop M888, Los Alamos, NM 87545 (United States); Read, Randy J. [University of Cambridge, Cambridge Institute for Medical Research, Cambridge CB2 0XY (United Kingdom); Adams, Paul D. [Lawrence Berkeley National Laboratory, One Cyclotron Road, Bldg 64R0121, Berkeley, CA 94720 (United States); Brunger, Axel T. [Stanford University, 318 Campus Drive West, Stanford, CA 94305 (United States); Afonine, Pavel V. [Lawrence Berkeley National Laboratory, One Cyclotron Road, Bldg 64R0121, Berkeley, CA 94720 (United States); Hung, Li-Wei [Los Alamos National Laboratory, Mail Stop M888, Los Alamos, NM 87545 (United States)

    2013-11-01

    A procedure for model building is described that combines morphing a model to match a density map, trimming the morphed model and aligning the model to a sequence. A procedure termed ‘morphing’ for improving a model after it has been placed in the crystallographic cell by molecular replacement has recently been developed. Morphing consists of applying a smooth deformation to a model to make it match an electron-density map more closely. Morphing does not change the identities of the residues in the chain, only their coordinates. Consequently, if the true structure differs from the working model by containing different residues, these differences cannot be corrected by morphing. Here, a procedure that helps to address this limitation is described. The goal of the procedure is to obtain a relatively complete model that has accurate main-chain atomic positions and residues that are correctly assigned to the sequence. Residues in a morphed model that do not match the electron-density map are removed. Each segment of the resulting trimmed morphed model is then assigned to the sequence of the molecule using information about the connectivity of the chains from the working model and from connections that can be identified from the electron-density map. The procedure was tested by application to a recently determined structure at a resolution of 3.2 Å and was found to increase the number of correctly identified residues in this structure from the 88 obtained using phenix.resolve sequence assignment alone (Terwilliger, 2003 ▶) to 247 of a possible 359. Additionally, the procedure was tested by application to a series of templates with sequence identities to a target structure ranging between 7 and 36%. The mean fraction of correctly identified residues in these cases was increased from 33% using phenix.resolve sequence assignment to 47% using the current procedure. The procedure is simple to apply and is available in the Phenix software package.

  11. Nanoplatform-based molecular imaging

    National Research Council Canada - National Science Library

    Chen, Xiaoyuan

    2011-01-01

    "Nanoplathform-Based Molecular Imaging provides rationale for using nanoparticle-based probes for molecular imaging, then discusses general strategies for this underutilized, yet promising, technology...

  12. Molecular-dynamics simulation of displacement cascades in Cu: analysis of replacement sequences

    International Nuclear Information System (INIS)

    King, W.E.; Benedek, R.

    1981-01-01

    Molecular-dynamics computer simulations of displacement cascades in copper have been performed for recoil energies up to 450 eV. Statistical analyses of the atomic replacements are presented. Linear replacement sequence lengths are extremely short on the average. The effect of the cooling phase of the cascade is discussed

  13. Age replacement policy based on imperfect repair with random probability

    International Nuclear Information System (INIS)

    Lim, J.H.; Qu, Jian; Zuo, Ming J.

    2016-01-01

    In most of literatures of age replacement policy, failures before planned replacement age can be either minimally repaired or perfectly repaired based on the types of failures, cost for repairs and so on. In this paper, we propose age replacement policy based on imperfect repair with random probability. The proposed policy incorporates the case that such intermittent failure can be either minimally repaired or perfectly repaired with random probabilities. The mathematical formulas of the expected cost rate per unit time are derived for both the infinite-horizon case and the one-replacement-cycle case. For each case, we show that the optimal replacement age exists and is finite. - Highlights: • We propose a new age replacement policy with random probability of perfect repair. • We develop the expected cost per unit time. • We discuss the optimal age for replacement minimizing the expected cost rate.

  14. Replacement

    Directory of Open Access Journals (Sweden)

    S. Radhakrishnan

    2014-03-01

    Full Text Available The fishmeal replaced with Spirulina platensis, Chlorella vulgaris and Azolla pinnata and the formulated diet fed to Macrobrachium rosenbergii postlarvae to assess the enhancement ability of non-enzymatic antioxidants (vitamin C and E, enzymatic antioxidants (superoxide dismutase (SOD and catalase (CAT and lipid peroxidation (LPx were analysed. In the present study, the S. platensis, C. vulgaris and A. pinnata inclusion diet fed groups had significant (P < 0.05 improvement in the levels of vitamins C and E in the hepatopancreas and muscle tissue. Among all the diets, the replacement materials in 50% incorporated feed fed groups showed better performance when compared with the control group in non-enzymatic antioxidant activity. The 50% fishmeal replacement (best performance diet fed groups taken for enzymatic antioxidant study, in SOD, CAT and LPx showed no significant increases when compared with the control group. Hence, the present results revealed that the formulated feed enhanced the vitamins C and E, the result of decreased level of enzymatic antioxidants (SOD, CAT and LPx revealed that these feeds are non-toxic and do not produce any stress to postlarvae. These ingredients can be used as an alternative protein source for sustainable Macrobrachium culture.

  15. Automated search-model discovery and preparation for structure solution by molecular replacement.

    Science.gov (United States)

    Keegan, Ronan M; Winn, Martyn D

    2007-04-01

    A novel automation pipeline for macromolecular structure solution by molecular replacement is described. There is a special emphasis on the discovery and preparation of a large number of search models, all of which can be passed to the core molecular-replacement programs. For routine molecular-replacement problems, the pipeline automates what a crystallographer might do and its value is simply one of convenience. For more difficult cases, the pipeline aims to discover the particular template structure and model edits required to produce a viable search model and may succeed in finding an efficacious combination that would be missed otherwise. The pipeline is described in detail and a number of examples are given. The examples are chosen to illustrate successes in real crystallography problems and also particular features of the pipeline. It is concluded that exploring a range of search models automatically can be valuable in many cases.

  16. Software-based annunciator replacement: a tale of two projects

    International Nuclear Information System (INIS)

    Simmons, G.T.

    2015-01-01

    Annunciator upgrade projects are often included as parts of operating plant life extension projects as the systems are old and replacement parts are difficult to source. This paper contains case studies of the software-based annunciator replacement projects at the Westinghouse SNUPPS training simulator in Pennsylvania and the Axpo Beznau nuclear power plant in Switzerland. Software-based annunciator systems can offer a number of feature enhancements including improved readability and operator awareness, easy configuration, alarm suppression features, and alarm management at operator workstations. This paper provides an overview of each project and discusses advantages, challenges, and lessons learned from both annunciator-replacement projects. (author)

  17. Software-based annunciator replacement: a tale of two projects

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, G.T., E-mail: simmongt@westinghouse.com [Westinghouse Electric Company LLC, Cranberry Township, PA (United States)

    2015-07-01

    Annunciator upgrade projects are often included as parts of operating plant life extension projects as the systems are old and replacement parts are difficult to source. This paper contains case studies of the software-based annunciator replacement projects at the Westinghouse SNUPPS training simulator in Pennsylvania and the Axpo Beznau nuclear power plant in Switzerland. Software-based annunciator systems can offer a number of feature enhancements including improved readability and operator awareness, easy configuration, alarm suppression features, and alarm management at operator workstations. This paper provides an overview of each project and discusses advantages, challenges, and lessons learned from both annunciator-replacement projects. (author)

  18. Has resin-based composite replaced amalgam?

    Science.gov (United States)

    Christensen, Gordon J; Child, Paul L

    2010-02-01

    The major health organizations in the world continue to accept amalgam use, but the "amalgam war" of the 1800s is still going on. The end is not in sight. There is little disagreement that amalgam serves well and, although controversial, it appears to have minimal to no health hazards. There is a wide variation in the relative amount of amalgam placed in developed countries, and many dentists in North America do not use it. However, amalgam is still being used at least some of the time by the majority of practitioners in North America, and most of those practitioners also place resin-based composite in Class II locations. The evolution from amalgam to tooth-colored restorations has been a slow and tumultuous journey. The acceptability of resin-based composite in Class II locations continues to be a question for some dentists, while others have concluded that amalgam is "dead." It would be highly desirable if some of dentists using the alleged poisonous properties of amalgam as a "practice building" ploy would find more legitimate methods to increase their practice activity.

  19. Polypeptides Based Molecular Electronics

    National Research Council Canada - National Science Library

    Lam, Yeng M; Mhaisalkar, Subodh; Li, Lain-Jong; Dravid, Vinayak P; Shekhawat, Gajendra S; Suri, Raman

    2008-01-01

    ... the formation of molecular devices such as transistors, diodes, and sensors. We have designed the peptides, arranged them on substrates using self-assembly, Dip-PEN nanolithography, and also e-beam assisted lithography...

  20. The use of VLD (vive la difference) in the molecular-replacement approach: a pipeline.

    Science.gov (United States)

    Carrozzini, Benedetta; Cascarano, Giovanni Luca; Comunale, Giuliana; Giacovazzo, Carmelo; Mazzone, Annamaria

    2013-06-01

    VLD (vive la difference) is a novel ab initio phasing approach that is able to drive random phases to the correct values. It has been applied to small, medium and protein structures provided that the data resolution was atomic. It has never been used for non-ab initio cases in which some phase information is available but the data resolution is usually very far from 1 Å. In this paper, the potential of VLD is tested for the first time for a classical non-ab initio problem: molecular replacement. Good preliminary experimental results encouraged the construction of a pipeline for leading partial molecular-replacement models with errors to refined solutions in a fully automated way. The pipeline moduli and their interaction are described, together with applications to a wide set of test cases.

  1. Approaches to ab initio molecular replacement of α-helical transmembrane proteins

    OpenAIRE

    Thomas, Jens M. H.; Simkovic, Felix; Keegan, Ronan; Mayans, Olga; Zhang, Chengxin; Zhang, Yang; Rigden, Daniel J.

    2017-01-01

    α-Helical transmembrane proteins are a ubiquitous and important class of proteins, but present difficulties for crystallographic structure solution. Here, the effectiveness of the AMPLE molecular replacement pipeline in solving α-helical transmembrane-protein structures is assessed using a small library of eight ideal helices, as well as search models derived from ab initio models generated both with and without evolutionary contact information. The ideal helices prove to be surprisingly effe...

  2. Opportunity-based age replacement policy with minimal repair

    International Nuclear Information System (INIS)

    Jhang, J.P.; Sheu, S.H.

    1999-01-01

    This paper proposes an opportunity-based age replacement policy with minimal repair. The system has two types of failures. Type I failures (minor failures) are removed by minimal repairs, whereas type II failures are removed by replacements. Type I and type II failures are age-dependent. A system is replaced at type II failure (catastrophic failure) or at the opportunity after age T, whichever occurs first. The cost of the minimal repair of the system at age z depends on the random part C(z) and the deterministic part c(z). The opportunity arises according to a Poisson process, independent of failures of the component. The expected cost rate is obtained. The optimal T * which would minimize the cost rate is discussed. Various special cases are considered. Finally, a numerical example is given

  3. Environmentally Optimal, Nutritionally Aware Beef Replacement Plant-Based Diets.

    Science.gov (United States)

    Eshel, Gidon; Shepon, Alon; Noor, Elad; Milo, Ron

    2016-08-02

    Livestock farming incurs large and varied environmental burdens, dominated by beef. Replacing beef with resource efficient alternatives is thus potentially beneficial, but may conflict with nutritional considerations. Here we show that protein-equivalent plant based alternatives to the beef portion of the mean American diet are readily devisible, and offer mostly improved nutritional profile considering the full lipid profile, key vitamins, minerals, and micronutrients. We then show that replacement diets require on average only 10% of land, 4% of greenhouse gas (GHG) emissions, and 6% of reactive nitrogen (Nr) compared to what the replaced beef diet requires. Applied to 320 million Americans, the beef-to-plant shift can save 91 million cropland acres (and 770 million rangeland acres), 278 million metric ton CO2e, and 3.7 million metric ton Nr annually. These nationwide savings are 27%, 4%, and 32% of the respective national environmental burdens.

  4. phenix.mr_rosetta: a new tool for difficult molecular replacement problems

    Energy Technology Data Exchange (ETDEWEB)

    Terwilliger, Thomas C [Los Alamos National Laboratory; Read, Randy [UNIV OF CAMBRIDGE; De Maio, Frank [UNIV OF WASHINGTON; Baker, David [UNIV OF WASHINGTON

    2011-01-12

    The PHENIX development team is working with the Baker laboratory at the University of Washington to combine the power of Rosetta structure modeling with PHENIX automated molecular replacement (MR), model-building, density modification, and refinement. The basic idea is to find MR solutions with phenix. automr, rebuild them with Rosetta, including electron density map information, then rebuild those models with phenix. autobuild. The combination of Rosetta rebuilding and phenix rebuilding is the key part of this method. MR solutions are found with phenix. automr (Phaser), scored with LLG (optionally following Rosetta relaxation), the best solutions are picked and rebuilt with Rosetta including map information, the resulting models are scored with Rosetta, and then rescored with LLG, and the top models are rebuilt with phenix. autobuild. It can be very useful for cases where the search model used in molecular replacement is slightly too distant to rebuild successfully with phenix. autobuild. It can also be useful in cases where the model is too distant to even find a molecular replacement solution, and prerefinement with Rosetta can yield an improved search model.

  5. Replacement method and enhanced replacement method versus the genetic algorithm approach for the selection of molecular descriptors in QSPR/QSAR theories.

    Science.gov (United States)

    Mercader, Andrew G; Duchowicz, Pablo R; Fernández, Francisco M; Castro, Eduardo A

    2010-09-27

    We compare three methods for the selection of optimal subsets of molecular descriptors from a much greater pool of such regression variables. On the one hand is our enhanced replacement method (ERM) and on the other is the simpler replacement method (RM) and the genetic algorithm (GA). These methods avoid the impracticable full search for optimal variables in large sets of molecular descriptors. Present results for 10 different experimental databases suggest that the ERM is clearly preferable to the GA that is slightly better than the RM. However, the latter approach requires the smallest amount of linear regressions and, consequently, the lowest computation time.

  6. Structure determination of an 11-subunit exosome in complex with RNA by molecular replacement

    Energy Technology Data Exchange (ETDEWEB)

    Makino, Debora Lika, E-mail: dmakino@biochem.mpg.de; Conti, Elena [Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried (Germany)

    2013-11-01

    The crystallographic steps towards the structure determination of a complete eukaryotic exosome complex bound to RNA are presented. Phasing of this 11-protein subunit complex was carried out via molecular replacement. The RNA exosome is an evolutionarily conserved multi-protein complex involved in the 3′ degradation of a variety of RNA transcripts. In the nucleus, the exosome participates in the maturation of structured RNAs, in the surveillance of pre-mRNAs and in the decay of a variety of noncoding transcripts. In the cytoplasm, the exosome degrades mRNAs in constitutive and regulated turnover pathways. Several structures of subcomplexes of eukaryotic exosomes or related prokaryotic exosome-like complexes are known, but how the complete assembly is organized to fulfil processive RNA degradation has been unclear. An atomic snapshot of a Saccharomyces cerevisiae 420 kDa exosome complex bound to an RNA substrate in the pre-cleavage state of a hydrolytic reaction has been determined. Here, the crystallographic steps towards the structural elucidation, which was carried out by molecular replacement, are presented.

  7. On the solution of the molecular-replacement problem at very low resolution: application to large complexes.

    Science.gov (United States)

    Urzhumtsev, A; Podjarny, A

    1995-11-01

    The applicability of the molecular-replacement (MR) method, implemented through the AMoRe package [Navaza (1994). Acta Cryst. A50, 157-163], is studied at very low resolution (d > 20 A) and for very large molecular complexes. Due to the nature of the low-resolution data, specific problems appear. In particular, rotation-function peaks are very broad and translation functions based on Patterson overlap show large spurious peaks. To solve these problems, the translation function is replaced by a search using amplitude correlation and a systematic three-dimensional angular search is performed around each rotation-function peak. Furthermore, these functions are applied in different resolution ranges during the same search. The corresponding algorithms are applied to two cases: the tRNA(Asp)-synthetase complex (neutron diffraction data) and a ribosome model crystal (calculated data). This new implementation is shown to solve the problem for a variety of search models, ranging from a detailed atomic model to a rough envelope.

  8. Approaches to ab initio molecular replacement of α-helical transmembrane proteins.

    Science.gov (United States)

    Thomas, Jens M H; Simkovic, Felix; Keegan, Ronan; Mayans, Olga; Zhang, Chengxin; Zhang, Yang; Rigden, Daniel J

    2017-12-01

    α-Helical transmembrane proteins are a ubiquitous and important class of proteins, but present difficulties for crystallographic structure solution. Here, the effectiveness of the AMPLE molecular replacement pipeline in solving α-helical transmembrane-protein structures is assessed using a small library of eight ideal helices, as well as search models derived from ab initio models generated both with and without evolutionary contact information. The ideal helices prove to be surprisingly effective at solving higher resolution structures, but ab initio-derived search models are able to solve structures that could not be solved with the ideal helices. The addition of evolutionary contact information results in a marked improvement in the modelling and makes additional solutions possible.

  9. Localization and orientation of heavy-atom cluster compounds in protein crystals using molecular replacement

    International Nuclear Information System (INIS)

    Dahms, Sven O.; Kuester, Miriam; Streb, Carsten; Roth, Christian; Sträter, Norbert; Than, Manuel E.

    2013-01-01

    A new approach is presented that allows the efficient localization and orientation of heavy-atom cluster compounds used in experimental phasing by a molecular replacement procedure. This permits the calculation of meaningful phases up to the highest resolution of the diffraction data. Heavy-atom clusters (HA clusters) containing a large number of specifically arranged electron-dense scatterers are especially useful for experimental phase determination of large complex structures, weakly diffracting crystals or structures with large unit cells. Often, the determination of the exact orientation of the HA cluster and hence of the individual heavy-atom positions proves to be the critical step in successful phasing and subsequent structure solution. Here, it is demonstrated that molecular replacement (MR) with either anomalous or isomorphous differences is a useful strategy for the correct placement of HA cluster compounds. The polyoxometallate cluster hexasodium α-metatungstate (HMT) was applied in phasing the structure of death receptor 6. Even though the HA cluster is bound in alternate partially occupied orientations and is located at a special position, its correct localization and orientation could be determined at resolutions as low as 4.9 Å. The broad applicability of this approach was demonstrated for five different derivative crystals that included the compounds tantalum tetradecabromide and trisodium phosphotungstate in addition to HMT. The correct placement of the HA cluster depends on the length of the intramolecular vectors chosen for MR, such that both a larger cluster size and the optimal choice of the wavelength used for anomalous data collection strongly affect the outcome

  10. Opportunity-based age replacement: exponentially distributed times between opportunities

    NARCIS (Netherlands)

    R. Dekker (Rommert); M.C. Dijkstra (Matthijs)

    1992-01-01

    textabstractThis article gives a full analysis of a component-replacement model in which preventive replacements are only possible at maintenance opportunities. These oppertunities arise according to a Poisson process, independently of failures of the component. Conditions for the existence of a

  11. Residue contacts predicted by evolutionary covariance extend the application of ab initio molecular replacement to larger and more challenging protein folds

    OpenAIRE

    Simkovic, Felix; Thomas, Jens M. H.; Keegan, Ronan M.; Winn, Martyn D.; Mayans, Olga; Rigden, Daniel J.

    2016-01-01

    For many protein families, the deluge of new sequence information together with new statistical protocols now allow the accurate prediction of contacting residues from sequence information alone. This offers the possibility of more accurate ab initio (non-homology-based) structure prediction. Such models can be used in structure solution by molecular replacement (MR) where the target fold is novel or is only distantly related to known structures. Here, AMPLE, an MR pipeline that assembles sea...

  12. A new hydroxyapatite-based biocomposite for bone replacement

    Energy Technology Data Exchange (ETDEWEB)

    Bellucci, Devis, E-mail: devis.bellucci@unimore.it [Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Via Vignolese 905, 41125 Modena (Italy); Sola, Antonella [Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Via Vignolese 905, 41125 Modena (Italy); Gazzarri, Matteo; Chiellini, Federica [Laboratory of Bioactive Polymeric Materials for Biomedical and Environmental Applications (BIOlab) and UdR INSTM, Department of Chemistry and Industrial Chemistry, University of Pisa, Via Vecchia Livornese 1291, 56122S. Piero a Grado, Pisa (Italy); Cannillo, Valeria [Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Via Vignolese 905, 41125 Modena (Italy)

    2013-04-01

    Since the 1970s, various types of ceramic, glass and glass–ceramic materials have been proposed and used to replace damaged bone in many clinical applications. Among them, hydroxyapatite (HA) has been successfully employed thanks to its excellent biocompatibility. On the other hand, the bioactivity of HA and its reactivity with bone can be improved through the addition of proper amounts of bioactive glasses, thus obtaining HA-based composites. Unfortunately, high temperature treatments (1200 °C ÷ 1300 °C) are usually required in order to sinter these systems, causing the bioactive glass to crystallize into a glass–ceramic and hence inhibiting the bioactivity of the resulting composite. In the present study novel HA-based composites are realized and discussed. The samples can be sintered at a relatively low temperature (800 °C), thanks to the employment of a new glass (BG{sub C}a) with a reduced tendency to crystallize compared to the widely used 45S5 Bioglass®. The rich glassy phase, which can be preserved during the thermal treatment, has excellent effects in terms of in vitro bioactivity; moreover, compared to composites based on 45S5 Bioglass® having the same HA/glass proportions, the samples based on BG{sub C}a displayed an earlier response in terms of cell proliferation. - Highlights: ► New apatite/bioglass composites are proposed and sintered at low temperature. ► The samples' glassy phase is preserved and the apatite decomposition is avoided. ► The rich glassy phase in the samples results in an excellent bioactivity. ► The samples are able to support cell adhesion and proliferation. ► The samples support faster cell proliferation compared to 45S5Bioglass-composites.

  13. A new hydroxyapatite-based biocomposite for bone replacement

    International Nuclear Information System (INIS)

    Bellucci, Devis; Sola, Antonella; Gazzarri, Matteo; Chiellini, Federica; Cannillo, Valeria

    2013-01-01

    Since the 1970s, various types of ceramic, glass and glass–ceramic materials have been proposed and used to replace damaged bone in many clinical applications. Among them, hydroxyapatite (HA) has been successfully employed thanks to its excellent biocompatibility. On the other hand, the bioactivity of HA and its reactivity with bone can be improved through the addition of proper amounts of bioactive glasses, thus obtaining HA-based composites. Unfortunately, high temperature treatments (1200 °C ÷ 1300 °C) are usually required in order to sinter these systems, causing the bioactive glass to crystallize into a glass–ceramic and hence inhibiting the bioactivity of the resulting composite. In the present study novel HA-based composites are realized and discussed. The samples can be sintered at a relatively low temperature (800 °C), thanks to the employment of a new glass (BG C a) with a reduced tendency to crystallize compared to the widely used 45S5 Bioglass®. The rich glassy phase, which can be preserved during the thermal treatment, has excellent effects in terms of in vitro bioactivity; moreover, compared to composites based on 45S5 Bioglass® having the same HA/glass proportions, the samples based on BG C a displayed an earlier response in terms of cell proliferation. - Highlights: ► New apatite/bioglass composites are proposed and sintered at low temperature. ► The samples' glassy phase is preserved and the apatite decomposition is avoided. ► The rich glassy phase in the samples results in an excellent bioactivity. ► The samples are able to support cell adhesion and proliferation. ► The samples support faster cell proliferation compared to 45S5Bioglass-composites

  14. Capillary crystallization and molecular-replacement solution of haemoglobin II from the clam Lucina pectinata

    International Nuclear Information System (INIS)

    Gavira, José A.; Jesus, Walleska de; Camara-Artigas, Ana; López-Garriga, Juan; García-Ruiz, Juan M.

    2006-01-01

    The haemoglobin II from the clam L. pectinata has been crystallized using counter-diffusion in single capillary in the presence of agarose to improve crystal quality. Initial phases have been obtained by molecular replacement. Haemoglobin II is one of three haemoglobins present in the cytoplasm of the Lucina pectinata mollusc that inhabits the Caribbean coast. Using HBII purified from its natural source, crystallization screening was performed using the counter-diffusion method with capillaries of 0.2 mm inner diameter. Crystals of HbII suitable for data collection and structure determination were grown in the presence of agarose at 0.1%(w/v) in order to improve their quality. The crystals belong to the tetragonal space group P4 2 2 1 2, with unit-cell parameters a = b = 73.92, c = 152.35 Å, and diffracted X-rays to a resolution of better than 2.0 Å. The asymmetric unit is a homodimer with a corresponding Matthews coefficient (V M ) of 3.15 Å 3 Da −1 and a solvent content of 61% by volume

  15. Localization and orientation of heavy-atom cluster compounds in protein crystals using molecular replacement.

    Science.gov (United States)

    Dahms, Sven O; Kuester, Miriam; Streb, Carsten; Roth, Christian; Sträter, Norbert; Than, Manuel E

    2013-02-01

    Heavy-atom clusters (HA clusters) containing a large number of specifically arranged electron-dense scatterers are especially useful for experimental phase determination of large complex structures, weakly diffracting crystals or structures with large unit cells. Often, the determination of the exact orientation of the HA cluster and hence of the individual heavy-atom positions proves to be the critical step in successful phasing and subsequent structure solution. Here, it is demonstrated that molecular replacement (MR) with either anomalous or isomorphous differences is a useful strategy for the correct placement of HA cluster compounds. The polyoxometallate cluster hexasodium α-metatungstate (HMT) was applied in phasing the structure of death receptor 6. Even though the HA cluster is bound in alternate partially occupied orientations and is located at a special position, its correct localization and orientation could be determined at resolutions as low as 4.9 Å. The broad applicability of this approach was demonstrated for five different derivative crystals that included the compounds tantalum tetradecabromide and trisodium phosphotungstate in addition to HMT. The correct placement of the HA cluster depends on the length of the intramolecular vectors chosen for MR, such that both a larger cluster size and the optimal choice of the wavelength used for anomalous data collection strongly affect the outcome.

  16. UHMWPE-based nanocomposite as a material for damaged cartilage replacement

    International Nuclear Information System (INIS)

    Senatov, F.S.; Kopylov, A.N.; Anisimova, N.Yu.; Kiselevsky, M.V.; Maksimkin, A.V.

    2015-01-01

    In the present work dispersion-strengthened nanocomposites based on ultra-high molecular weight polyethylene (UHMWPE) after mechanical activation were studied. Mechanical activation was performed for hardening of the boundaries between the polymer particles, reducing the fusion defects and increasing of wear-resistance. Three types of samples were prepared: UHMWPE, UHMWPE/Al 2 O 3 nanocomposite and UHMWPE/Al 2 O 3 nanocomposite after mechanical activation. UHMWPE/Al 2 O 3 nanocomposites prepared with mechanical activation show the best mechanical properties in compression and higher wear-resistance. UHMWPE/Al 2 O 3 nanocomposites prepared with mechanical activation were chosen for in vivo study by orthotopical transplantation in rats. Animals' activity has been being monitored for 60 days after surgery. No signs of inflammation, cellular infiltration, destruction of material or bone–cartilage defect were found. Implanted sample has not changed its position of implantation, there were no any shifts. Obtained data shows that UHMWPE-based nanocomposite is a promising material for creating bioimplants for cartilage defect replacement. - Highlights: • Mechanical activation of UHMWPE composite leads to changing of fracture mechanism. • Mechanical activation leads to increasing of wear-resistance of UHMWPE composite. • The presence of Al 2 O 3 in grain boundaries of UHMWPE inhibits crack growth. • Complete integration of UHMWPE-based implant in cartilage defect of rat was shown. • UHMWPE/Al 2 O 3 nanocomposite may be recommended for use in cartilage replacement

  17. Improving NMR protein structure quality by Rosetta refinement: a molecular replacement study.

    Science.gov (United States)

    Ramelot, Theresa A; Raman, Srivatsan; Kuzin, Alexandre P; Xiao, Rong; Ma, Li-Chung; Acton, Thomas B; Hunt, John F; Montelione, Gaetano T; Baker, David; Kennedy, Michael A

    2009-04-01

    The structure of human protein HSPC034 has been determined by both solution nuclear magnetic resonance (NMR) spectroscopy and X-ray crystallography. Refinement of the NMR structure ensemble, using a Rosetta protocol in the absence of NMR restraints, resulted in significant improvements not only in structure quality, but also in molecular replacement (MR) performance with the raw X-ray diffraction data using MOLREP and Phaser. This method has recently been shown to be generally applicable with improved MR performance demonstrated for eight NMR structures refined using Rosetta (Qian et al., Nature 2007;450:259-264). Additionally, NMR structures of HSPC034 calculated by standard methods that include NMR restraints have improvements in the RMSD to the crystal structure and MR performance in the order DYANA, CYANA, XPLOR-NIH, and CNS with explicit water refinement (CNSw). Further Rosetta refinement of the CNSw structures, perhaps due to more thorough conformational sampling and/or a superior force field, was capable of finding alternative low energy protein conformations that were equally consistent with the NMR data according to the Recall, Precision, and F-measure (RPF) scores. On further examination, the additional MR-performance shortfall for NMR refined structures as compared with the X-ray structure were attributed, in part, to crystal-packing effects, real structural differences, and inferior hydrogen bonding in the NMR structures. A good correlation between a decrease in the number of buried unsatisfied hydrogen-bond donors and improved MR performance demonstrates the importance of hydrogen-bond terms in the force field for improving NMR structures. The superior hydrogen-bond network in Rosetta-refined structures demonstrates that correct identification of hydrogen bonds should be a critical goal of NMR structure refinement. Inclusion of nonbivalent hydrogen bonds identified from Rosetta structures as additional restraints in the structure calculation results in

  18. Replacement of asymmetric synaptic profiles in the molecular layer of dentate gyrus following cycloheximide in the pilocarpine model in rats.

    Directory of Open Access Journals (Sweden)

    Simone eBittencourt

    2015-11-01

    Full Text Available Mossy fiber sprouting is among the best-studied forms of post-lesional synaptic plasticity and is regarded by many as contributory to seizures in both humans and animal models of epilepsy. It is not known whether mossy fiber sprouting increases the number of synapses in the molecular layer or merely replaces lost contacts. Using the pilocarpine model of status epilepticus to induce mossy fiber sprouting, and cycloheximide to block this sprouting, we evaluated at the ultrastructural level the number and type of asymmetric synaptic contacts in the molecular layer of the dentate gyrus. As expected, whereas pilocarpine-treated rats had dense silver grain deposits in the inner molecular layer (reflecting mossy fiber sprouting, pilocarpine+cycloheximide-treated animals did not differ from controls. Both groups of treated rats (Pilo group and CHX+Pilo group had reduced density of asymmetric synaptic profiles (putative excitatory synaptic contacts, which was greater for cycloheximide-treated animals. For both treated groups the loss of excitatory synaptic contacts was even greater in the outer molecular layer than in the best studied inner molecular layer (in which mossy fiber sprouting occurs. These results indicate that mossy fiber sprouting tends to replace lost synaptic contacts rather than increase the absolute number of contacts. We speculate that the overall result is more consistent with restored rather than with increased excitability.

  19. Mechanistic and morphological origins of ultra-high molecular weight polyethylene wear debris in total joint replacement prostheses.

    Science.gov (United States)

    Wang, A; Stark, C; Dumbleton, J H

    1996-01-01

    The mechanistic and morphological origins of microscopic wear debris generated from UHMWPE articular surfaces in total joint replacement prostheses are investigated in this study. It was found experimentally that the molecular chain structure at the articulating surface of UHMWPE undergoes a re-organization process due to strain accumulation caused by surface traction. This molecular re-organization process creates a fibre-like surface texture that exhibits an anisotropic behaviour similar to a unidirectionally reinforced polymer composite. This composite responds to stresses favourably if loaded along the fibre axis but unfavourably if loaded off axis. Due to the very complex multi-axial motion/loading nature at the articular surfaces in total joint replacements, the stress tensors applied to each localized asperity contact area continuously change their directions and magnitudes. These changes in the localized stress field create an off-axis loading situation at each localized contact zone with respect to the orientation of the molecular chains. Depending on the off-axis angle, failure of the molecular structure occurs in three different ways: tensile rupture at very small off-axis angles, shear rupture at intermediate off-axis angles and transverse splitting at large off-axis angles. These failure mechanisms all produce similar fibre-like wear debris. However, the failure stresses differ significantly among the three modes. According to this molecular wear theory, the preferred polymer microstructure for optimal wear resistance would be a three-dimensionally strong network connected by covalent bonds between molecular chains. For UHMWPE, a three-dimensional molecular network can be created by radiation induced cross-linking. Experiments conducted on both gamma irradiated and unirradiated UHMWPE specimens using a linear wear machine and multi-axial joint simulators confirmed the validity of the molecular wear theory.

  20. NVR-BIP: Nuclear Vector Replacement using Binary Integer Programming for NMR Structure-Based Assignments.

    Science.gov (United States)

    Apaydin, Mehmet Serkan; Çatay, Bülent; Patrick, Nicholas; Donald, Bruce R

    2011-05-01

    Nuclear magnetic resonance (NMR) spectroscopy is an important experimental technique that allows one to study protein structure and dynamics in solution. An important bottleneck in NMR protein structure determination is the assignment of NMR peaks to the corresponding nuclei. Structure-based assignment (SBA) aims to solve this problem with the help of a template protein which is homologous to the target and has applications in the study of structure-activity relationship, protein-protein and protein-ligand interactions. We formulate SBA as a linear assignment problem with additional nuclear overhauser effect constraints, which can be solved within nuclear vector replacement's (NVR) framework (Langmead, C., Yan, A., Lilien, R., Wang, L. and Donald, B. (2003) A Polynomial-Time Nuclear Vector Replacement Algorithm for Automated NMR Resonance Assignments. Proc. the 7th Annual Int. Conf. Research in Computational Molecular Biology (RECOMB) , Berlin, Germany, April 10-13, pp. 176-187. ACM Press, New York, NY. J. Comp. Bio. , (2004), 11, pp. 277-298; Langmead, C. and Donald, B. (2004) An expectation/maximization nuclear vector replacement algorithm for automated NMR resonance assignments. J. Biomol. NMR , 29, 111-138). Our approach uses NVR's scoring function and data types and also gives the option of using CH and NH residual dipolar coupling (RDCs), instead of NH RDCs which NVR requires. We test our technique on NVR's data set as well as on four new proteins. Our results are comparable to NVR's assignment accuracy on NVR's test set, but higher on novel proteins. Our approach allows partial assignments. It is also complete and can return the optimum as well as near-optimum assignments. Furthermore, it allows us to analyze the information content of each data type and is easily extendable to accept new forms of input data, such as additional RDCs.

  1. Repair or replacement of defective restorations by dentists in The Dental Practice-Based Research Network

    DEFF Research Database (Denmark)

    Gordan, Valeria V; Riley, Joseph L; Geraldeli, Saulo

    2012-01-01

    The authors aimed to determine whether dentists in practices belonging to The Dental Practice-Based Research Network (DPBRN) were more likely to repair or to replace a restoration that they diagnosed as defective; to quantify dentists' specific reasons for repairing or replacing restorations; and......; and to test the hypothesis that certain dentist-, patient- and restoration-related variables are associated with the decision between repairing and replacing restorations....

  2. Ensembles generated from crystal structures of single distant homologues solve challenging molecular-replacement cases in AMPLE.

    Science.gov (United States)

    Rigden, Daniel J; Thomas, Jens M H; Simkovic, Felix; Simpkin, Adam; Winn, Martyn D; Mayans, Olga; Keegan, Ronan M

    2018-03-01

    Molecular replacement (MR) is the predominant route to solution of the phase problem in macromolecular crystallography. Although routine in many cases, it becomes more effortful and often impossible when the available experimental structures typically used as search models are only distantly homologous to the target. Nevertheless, with current powerful MR software, relatively small core structures shared between the target and known structure, of 20-40% of the overall structure for example, can succeed as search models where they can be isolated. Manual sculpting of such small structural cores is rarely attempted and is dependent on the crystallographer's expertise and understanding of the protein family in question. Automated search-model editing has previously been performed on the basis of sequence alignment, in order to eliminate, for example, side chains or loops that are not present in the target, or on the basis of structural features (e.g. solvent accessibility) or crystallographic parameters (e.g. B factors). Here, based on recent work demonstrating a correlation between evolutionary conservation and protein rigidity/packing, novel automated ways to derive edited search models from a given distant homologue over a range of sizes are presented. A variety of structure-based metrics, many readily obtained from online webservers, can be fed to the MR pipeline AMPLE to produce search models that succeed with a set of test cases where expertly manually edited comparators, further processed in diverse ways with MrBUMP, fail. Further significant performance gains result when the structure-based distance geometry method CONCOORD is used to generate ensembles from the distant homologue. To our knowledge, this is the first such approach whereby a single structure is meaningfully transformed into an ensemble for the purposes of MR. Additional cases further demonstrate the advantages of the approach. CONCOORD is freely available and computationally inexpensive, so

  3. [Molecular bases of prion diseases].

    Science.gov (United States)

    Pokrovskiĭ, V I; Kiselev, O I

    1998-01-01

    The paper briefly analyzes the origin of priones and their association with the cellular gene and homologous protein of diseases in man and animals. There is evidence for a direct relationship of the agents that cause spongious encephalitis in the cattle and a new type of Creutzfeldt-Jacob disease in man. The molecular organization of priones and the conformational cellular protein changes underlying the infectious activation of the cell homologue of priones. Emphasis is first laid on the capacity of the cell homologue of priones and their infectiously active derivative to bind to DNA or RNA. In the context of concepts of the priones yeasts an attempt was made to explain the reproduction through the altered control of translation of mRNA that encodes the cellular homologue of priones, which accounts for the duration of the incubation period of the disease. The infections caused by priones are referred to as the so-called slow infections. But in the context of the proposed hypothesis, an infective process in the tissues did not really have some typical signs of infection and resembles accumulation diseases more without the replicative burst typical of infectious processes. The paper gives data on the vital cycle of priones in infected animals and changes in the accumulation of an infective agent. This assesses the currently available diagnostic methods and gives preference to the methods which will be based on the use of monoclonal antibodies that specifically recognize the conformationally altered form of an infectious prione or on the identification of primary oligomeric forms which manifest the onset of amyloidization of the damaged tissues. The main conclusion of the paper is that protein prionization is a common biological phenomenon and the diseases caused by these processes will increase in number in the near future, which makes it necessary to develop diagnostic methods and universal treatments of diseases, such as bacterial infections by using antibiotics.

  4. Bases moleculares de las leucemias agudas

    Directory of Open Access Journals (Sweden)

    G. Martínez Antuña

    2006-04-01

    Full Text Available El gran desarrollo de la biología molecular en los últimos años ha contribuido a un importante avance en los conocimientos relacionados con las bases moleculares de las leucemias agudas (LA. Ademas de profundizar en la biología de estas enfermedades y conocer las bases moleculares, ha renido también gran impacto en mejorar el resultado de los tratamientos y disminuir la toxicidad de las terapias.

  5. UHMWPE-based nanocomposite as a material for damaged cartilage replacement

    Energy Technology Data Exchange (ETDEWEB)

    Senatov, F.S., E-mail: Senatov@misis.ru [National University of Science and Technology “MISIS”, 119049, Leninskiy pr. 4, Moscow (Russian Federation); Kopylov, A.N.; Anisimova, N.Yu.; Kiselevsky, M.V. [N.N. Blokhin Russian Cancer Research Center, 115478, Kashirskoye sh. 23, Moscow (Russian Federation); Maksimkin, A.V. [National University of Science and Technology “MISIS”, 119049, Leninskiy pr. 4, Moscow (Russian Federation)

    2015-03-01

    In the present work dispersion-strengthened nanocomposites based on ultra-high molecular weight polyethylene (UHMWPE) after mechanical activation were studied. Mechanical activation was performed for hardening of the boundaries between the polymer particles, reducing the fusion defects and increasing of wear-resistance. Three types of samples were prepared: UHMWPE, UHMWPE/Al{sub 2}O{sub 3} nanocomposite and UHMWPE/Al{sub 2}O{sub 3} nanocomposite after mechanical activation. UHMWPE/Al{sub 2}O{sub 3} nanocomposites prepared with mechanical activation show the best mechanical properties in compression and higher wear-resistance. UHMWPE/Al{sub 2}O{sub 3} nanocomposites prepared with mechanical activation were chosen for in vivo study by orthotopical transplantation in rats. Animals' activity has been being monitored for 60 days after surgery. No signs of inflammation, cellular infiltration, destruction of material or bone–cartilage defect were found. Implanted sample has not changed its position of implantation, there were no any shifts. Obtained data shows that UHMWPE-based nanocomposite is a promising material for creating bioimplants for cartilage defect replacement. - Highlights: • Mechanical activation of UHMWPE composite leads to changing of fracture mechanism. • Mechanical activation leads to increasing of wear-resistance of UHMWPE composite. • The presence of Al{sub 2}O{sub 3} in grain boundaries of UHMWPE inhibits crack growth. • Complete integration of UHMWPE-based implant in cartilage defect of rat was shown. • UHMWPE/Al{sub 2}O{sub 3} nanocomposite may be recommended for use in cartilage replacement.

  6. Optimal replacement policies for dairy cows based on daily yield measurements

    DEFF Research Database (Denmark)

    Nielsen, Lars Relund; Jørgensen, Erik; Kristensen, Anders Ringgaard

    2010-01-01

    describes the first step of developing an MDP model that can be integrated into a modern herd management system. A hierarchical MDP was formulated for the dairy cow replacement problem with stage lengths of 1 d. It can be used to assist the farmer in replacement decisions on a daily basis and is based...

  7. Replaceable Substructures for Efficient Part-Based Modeling

    KAUST Repository

    Liu, Han

    2015-05-01

    A popular mode of shape synthesis involves mixing and matching parts from different objects to form a coherent whole. The key challenge is to efficiently synthesize shape variations that are plausible, both locally and globally. A major obstacle is to assemble the objects with local consistency, i.e., all the connections between parts are valid with no dangling open connections. The combinatorial complexity of this problem limits existing methods in geometric and/or topological variations of the synthesized models. In this work, we introduce replaceable substructures as arrangements of parts that can be interchanged while ensuring boundary consistency. The consistency information is extracted from part labels and connections in the original source models. We present a polynomial time algorithm that discovers such substructures by working on a dual of the original shape graph that encodes inter-part connectivity. We demonstrate the algorithm on a range of test examples producing plausible shape variations, both from a geometric and from a topological viewpoint. © 2015 The Author(s) Computer Graphics Forum © 2015 The Eurographics Association and John Wiley & Sons Ltd. Published by John Wiley & Sons Ltd.

  8. The utility of comparative models and the local model quality for protein crystal structure determination by Molecular Replacement

    Directory of Open Access Journals (Sweden)

    Pawlowski Marcin

    2012-11-01

    Full Text Available Abstract Background Computational models of protein structures were proved to be useful as search models in Molecular Replacement (MR, a common method to solve the phase problem faced by macromolecular crystallography. The success of MR depends on the accuracy of a search model. Unfortunately, this parameter remains unknown until the final structure of the target protein is determined. During the last few years, several Model Quality Assessment Programs (MQAPs that predict the local accuracy of theoretical models have been developed. In this article, we analyze whether the application of MQAPs improves the utility of theoretical models in MR. Results For our dataset of 615 search models, the real local accuracy of a model increases the MR success ratio by 101% compared to corresponding polyalanine templates. On the contrary, when local model quality is not utilized in MR, the computational models solved only 4.5% more MR searches than polyalanine templates. For the same dataset of the 615 models, a workflow combining MR with predicted local accuracy of a model found 45% more correct solution than polyalanine templates. To predict such accuracy MetaMQAPclust, a “clustering MQAP” was used. Conclusions Using comparative models only marginally increases the MR success ratio in comparison to polyalanine structures of templates. However, the situation changes dramatically once comparative models are used together with their predicted local accuracy. A new functionality was added to the GeneSilico Fold Prediction Metaserver in order to build models that are more useful for MR searches. Additionally, we have developed a simple method, AmIgoMR (Am I good for MR?, to predict if an MR search with a template-based model for a given template is likely to find the correct solution.

  9. Thermomechanical behavior of virgin and highly crosslinked ultra-high molecular weight polyethylene used in total joint replacements.

    Science.gov (United States)

    Kurtz, S M; Villarraga, M L; Herr, M P; Bergström, J S; Rimnac, C M; Edidin, A A

    2002-09-01

    Three series of uniaxial tension and compression tests were conducted on two conventional and two highly crosslinked ultra-high molecular weight polyethylenes (UHMWPEs) all prepared from the same lot of medical grade GUR 1050. The conventional materials were unirradiated (control) and gamma irradiated in nitrogen with a dose of 30 kGy. The highly crosslinked UHMWPEs were gamma irradiated at room temperature with 100 kGy and then thermally processed by either annealing below the melt transition at 100 degrees C or by remelting above the melt transition at 150 degrees C. The true stress-strain behavior of the four UHMWPE materials was characterized as a function of strain rate (between 0.02 and 0.10 s(-1)) and test temperature (20-60 degrees C). Although annealing and remelting of UHMWPE are primarily considered as methods of improving oxidation resistance, thermal processing was found to significantly impact the crystallinity, and hence the mechanical behavior, of the highly crosslinked UHMWPE. The crystallinity and radiation dose were key predictors of the uniaxial yielding, plastic flow, and failure properties of conventional and highly crosslinked UHMWPEs. The thermomechanical behavior of UHMWPE was accurately predicted using an Arrhenius model, and the associated activation energies for thermal softening were related to the crystallinity of the polymers. The conventional and highly crosslinked UHMWPEs exhibited low strain rate dependence in power law relationships, comparable to metals. In light of the unifying trends observed in the true stress-strain curves of the four materials investigated in this study, both crosslinking (governed by the gamma radiation dose) and crystallinity (governed by the thermal processing) were found to be useful predictors of the mechanical behavior of UHMWPE for a wide range of test temperatures and rates. The data collected in this study will be used to develop constitutive models based on the physics of polymer systems for

  10. Replacing fossil based plastic performance products by bio-based plastic products-Technical feasibility.

    Science.gov (United States)

    van den Oever, Martien; Molenveld, Karin

    2017-07-25

    Larger scale market introduction of new bio-based products requires a clear advantage regarding sustainability, as well as an adequate techno-economic positioning relative to fossil based products. In a previous paper [Broeren et al., 2016], LCA results per kg and per functionality equivalent of bio-based plastics were presented, together with economic considerations. The present paper discusses the mechanical and thermal properties of a range of commercially available bio-based plastics based on polylactic acid (PLA), cellulose esters, starch and polyamides, and the feasibility of replacing fossil-based counterparts based on performance. The evaluation is approached from an end user perspective. First, potentially suitable bio-based plastics are selected based on manufacturers' specifications in technical data sheets, then a first experimental evaluation is performed on injection moulded ISO specimens, and finally a further selection of plastics is tested on large 50×70cm panels. This technical feasibility study indicates that so far bio-based plastics do not completely match the properties of high performance materials like flame retardant V-0 PC/ABS blends used in electronic devices. The performance gap is being decreased by the development of stereocomplex PLA and hybrid PLA blends with polycarbonate, which offer clearly improved properties with respect to maximum usage temperature and toughness. In addition, several materials meet the V-0 flammability requirements needed in specific durable applications. On the other hand, improving these properties so far has negative consequences for the bio-based content. This study also shows that replacement of bulk polymers like PS is feasible using PLA compounds with a bio-based content as high as 85%. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Polymerase chain reaction (PCR) based molecular characterization ...

    African Journals Online (AJOL)

    Polymerase chain reaction (PCR) based molecular characterization of popular wheat varieties of Khyber Pukhtunkhwa (KPK) region of Pakistan. ... Molecular markers used in this study show high rate of genetic diversity that can be used to assist a breeding program for the improvement of wheat in KPK-Pakistan. Key words: ...

  12. Purification, crystallization, preliminary X-ray diffraction and molecular-replacement studies of great cormorant (Phalacrocorax carbo) haemoglobin

    Energy Technology Data Exchange (ETDEWEB)

    Jagadeesan, G. [Presidency College, Chennai 600 005 (India); Malathy, P.; Gunasekaran, K. [University of Madras, Chennai 600 025 (India); Harikrishna Etti, S. [GKM College of Engineering and Technology, Kamaraj Salai, Chennai 600 063 (India); Aravindhan, S., E-mail: aravindhanpresidency@gmail.com [Presidency College, Chennai 600 005 (India)

    2014-10-25

    The great cormorant hemoglobin has been isolated, purified and crystallized and the three dimensional structure is solved using molecular replacement technique. Haemoglobin is the iron-containing oxygen-transport metalloprotein that is present in the red blood cells of all vertebrates. In recent decades, there has been substantial interest in attempting to understand the structural basis and functional diversity of avian haemoglobins. Towards this end, purification, crystallization, preliminary X-ray diffraction and molecular-replacement studies have been carried out on cormorant (Phalacrocorax carbo) haemoglobin. Crystals were grown by the hanging-drop vapour-diffusion method using PEG 3350, NaCl and glycerol as precipitants. The crystals belonged to the trigonal system P3{sub 1}21, with unit-cell parameters a = b = 55.64, c = 153.38 Å, β = 120.00°; a complete data set was collected to a resolution of 3.5 Å. Matthews coefficient analysis indicated that the crystals contained a half-tetramer in the asymmetric unit.

  13. Spare Parts Demand Analysis Method Based on Field Replaceable Unit

    Science.gov (United States)

    Zhu, Min; Xu, Zijian; Guo, Ming; Li, Biao

    2017-10-01

    It is based on the reliability of spare parts optimization modeling, and the influence of failure rate, fixability, importance and availability on spare parts reserves is added to the model, and the weight of each spare part is calculated by fuzzy analytic hierarchy process.

  14. Evidence-base for aspirin as venous thromboembolic prophylaxis following joint replacement

    OpenAIRE

    Jameson, S. S.; Baker, P. N.; Deehan, D. J.; Port, A.; Reed, M. R.

    2014-01-01

    The National Institute for Health and Clinical Excellence (NICE) has thus far relied on historical data and predominantly industry-sponsored trials to provide evidence for venous thromboembolic (VTE) prophylaxis in joint replacement patients. We argue that the NICE guidelines may be reliant on assumptions that are in need of revision. Following the publication of large scale, independent observational studies showing little difference between low-molecular-weight heparins and aspirin, and rec...

  15. Progress on RNAi-based molecular medicines

    Directory of Open Access Journals (Sweden)

    Chen J

    2012-07-01

    Full Text Available Jing Chen, Jianping XieInstitute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, ChinaAbstract: RNA interference (RNAi is a promising strategy to suppress the expression of disease-relevant genes and induce post-transcriptional gene silencing. Their simplicity and stability endow RNAi with great advantages in molecular medicine. Several RNAi-based drugs are in various stages of clinical investigation. This review summarizes the ongoing research endeavors on RNAi in molecular medicine, delivery systems for RNAi-based drugs, and a compendium of RNAi drugs in different stages of clinical development. Of special interest are RNAi-based drug target discovery and validation, delivery systems for RNAi-based drugs, such as nanoparticles, rabies virus protein-based vehicles, and bacteriophages for RNA packaging.Keywords: RNA interference, delivery systems, liposome, nanoparticle, molecular medicines

  16. Calculating evidence-based renal replacement therapy - Introducing an excel-based calculator to improve prescribing and delivery in renal replacement therapy - A before and after study.

    Science.gov (United States)

    Cottle, Daniel; Mousdale, Stephen; Waqar-Uddin, Haroon; Tully, Redmond; Taylor, Benjamin

    2016-02-01

    Transferring the theoretical aspect of continuous renal replacement therapy to the bedside and delivering a given "dose" can be difficult. In research, the "dose" of renal replacement therapy is given as effluent flow rate in ml kg -1  h -1 . Unfortunately, most machines require other information when they are initiating therapy, including blood flow rate, pre-blood pump flow rate, dialysate flow rate, etc. This can lead to confusion, resulting in patients receiving inappropriate doses of renal replacement therapy. Our aim was to design an excel calculator which would personalise patient's treatment, deliver an effective, evidence-based dose of renal replacement therapy without large variations in practice and prolong filter life. Our calculator prescribes a haemodialfiltration dose of 25 ml kg -1  h -1 whilst limiting the filtration fraction to 15%. We compared the episodes of renal replacement therapy received by a historical group of patients, by retrieving their data stored on the haemofiltration machines, to a group where the calculator was used. In the second group, the data were gathered prospectively. The median delivered dose reduced from 41.0 ml kg -1  h -1 to 26.8 ml kg -1  h -1 with reduced variability that was significantly closer to the aim of 25 ml kg -1 .h -1 ( p  < 0.0001). The median treatment time increased from 8.5 h to 22.2 h ( p  = 0.00001). Our calculator significantly reduces variation in prescriptions of continuous veno-venous haemodiafiltration and provides an evidence-based dose. It is easy to use and provides personal care for patients whilst optimizing continuous veno-venous haemodiafiltration delivery and treatment times.

  17. Supercapacitor performance evaluation in replacing battery based on charging and discharging current characteristics

    Science.gov (United States)

    Sani, A.; Siahaan, S.; Mubarakah, N.; Suherman

    2018-02-01

    Supercapacitor is a new device of energy storage, which has much difference between ordinary capacitors and batteries. Supercapacitor have higher capacitance and energy density than regular capacitors. The supercapacitor also has a fast charging time, as well as a long life. To be used as a battery replacement please note the internal parameters of the battery to be replaced. In this paper conducted a simulation study to utilize supercapacitor as a replacement battery. The internal parameters of the battery and the supercapacitor are obtained based on the characteristics of charging and discharging current using a predefined equivalent circuit model. The battery to be replaced is a 12-volt lead-acid type, 6.5 Ah which is used on motorcycles with 6A charging and discharging currents. Super capacitor replacement capacitor is a capacity of 1600F, 2.7V which is connected in series as many as 6 pieces with 16.2 volt terminal voltage and charging current 12A. To obtain the same supercapacitor characteristic as the battery characteristic to be replaced, modification of its internal parameters is made. The results show that the super-capacitor can replace the battery function for 1000 seconds.

  18. Value-based procurement of prostheses for total knee replacement.

    Science.gov (United States)

    Messori, Andrea; Trippoli, Sabrina

    2017-12-14

    Cost-effectiveness evaluations concerning devices for total knee arthroplasty (TKA) have little impact on real-life management of these devices. This study explored how pharmacoeconomic models can inform the procurement of TKA devices to improve their value for money. Our study included three phases: i) literature search for data of outcome, cost, and device type in TKA; ii) development of a Markov model predicting costs, QALYs, and net monetary benefit (NMB); iii) simulation of tenders aimed at value-based device procurement. Phases 1 and 2 were managed by selecting a single study as the source of data for our analysis. In Phase 3, each TKA device was associated with its values of NMB, and the tender scores were estimated. Finally, the ranking of each device in the simulated tender was determined. We identified a study published in 2016 as our source of data. Five devices were evaluated. For these devices, QALYs were 7.3952, 7.2939, 7.4952, 7.1919, 7.2930; NMB: £142,005, £140,653, £144,184, £138,040, £140,261; tender scores: 64.53, 42.53, 100, 0, 36.15, respectively. We showed that incorporating the principles of cost-effectiveness into the tendering process is feasible for TKA devices. This can maximize the value for money for these devices.

  19. A Hadoop-based Molecular Docking System

    Science.gov (United States)

    Dong, Yueli; Guo, Quan; Sun, Bin

    2017-10-01

    Molecular docking always faces the challenge of managing tens of TB datasets. It is necessary to improve the efficiency of the storage and docking. We proposed the molecular docking platform based on Hadoop for virtual screening, it provides the preprocessing of ligand datasets and the analysis function of the docking results. A molecular cloud database that supports mass data management is constructed. Through this platform, the docking time is reduced, the data storage is efficient, and the management of the ligand datasets is convenient.

  20. Ultrathin inorganic molecular nanowire based on polyoxometalates

    Science.gov (United States)

    Zhang, Zhenxin; Murayama, Toru; Sadakane, Masahiro; Ariga, Hiroko; Yasuda, Nobuhiro; Sakaguchi, Norihito; Asakura, Kiyotaka; Ueda, Wataru

    2015-01-01

    The development of metal oxide-based molecular wires is important for fundamental research and potential practical applications. However, examples of these materials are rare. Here we report an all-inorganic transition metal oxide molecular wire prepared by disassembly of larger crystals. The wires are comprised of molybdenum(VI) with either tellurium(IV) or selenium(IV): {(NH4)2[XMo6O21]}n (X=tellurium(IV) or selenium(IV)). The ultrathin molecular nanowires with widths of 1.2 nm grow to micrometre-scale crystals and are characterized by single-crystal X-ray analysis, Rietveld analysis, scanning electron microscopy, X-ray photoelectron spectroscopy, ultraviolet–visible spectroscopy, thermal analysis and elemental analysis. The crystals can be disassembled into individual molecular wires through cation exchange and subsequent ultrasound treatment, as visualized by atomic force microscopy and transmission electron microscopy. The ultrathin molecular wire-based material exhibits high activity as an acid catalyst, and the band gap of the molecular wire-based crystal is tunable by heat treatment. PMID:26139011

  1. A molecular breadboard: Removal and replacement of subunits in a hepatitis B virus capsid.

    Science.gov (United States)

    Lee, Lye Siang; Brunk, Nicholas; Haywood, Daniel G; Keifer, David; Pierson, Elizabeth; Kondylis, Panagiotis; Wang, Joseph Che-Yen; Jacobson, Stephen C; Jarrold, Martin F; Zlotnick, Adam

    2017-11-01

    Hepatitis B virus (HBV) core protein is a model system for studying assembly and disassembly of icosahedral structures. Controlling disassembly will allow re-engineering the 120 subunit HBV capsid, making it a molecular breadboard. We examined removal of subunits from partially crosslinked capsids to form stable incomplete particles. To characterize incomplete capsids, we used two single molecule techniques, resistive-pulse sensing and charge detection mass spectrometry. We expected to find a binomial distribution of capsid fragments. Instead, we found a preponderance of 3 MDa complexes (90 subunits) and no fragments smaller than 3 MDa. We also found 90-mers in the disassembly of uncrosslinked HBV capsids. 90-mers seem to be a common pause point in disassembly reactions. Partly explaining this result, graph theory simulations have showed a threshold for capsid stability between 80 and 90 subunits. To test a molecular breadboard concept, we showed that missing subunits could be refilled resulting in chimeric, 120 subunit particles. This result may be a means of assembling unique capsids with functional decorations. © 2017 The Protein Society.

  2. Gas Sensors Based on Molecular Imprinting Technology.

    Science.gov (United States)

    Zhang, Yumin; Zhang, Jin; Liu, Qingju

    2017-07-04

    Molecular imprinting technology (MIT); often described as a method of designing a material to remember a target molecular structure (template); is a technique for the creation of molecularly imprinted polymers (MIPs) with custom-made binding sites complementary to the target molecules in shape; size and functional groups. MIT has been successfully applied to analyze; separate and detect macromolecular organic compounds. Furthermore; it has been increasingly applied in assays of biological macromolecules. Owing to its unique features of structure specificity; predictability; recognition and universal application; there has been exploration of the possible application of MIPs in the field of highly selective gas sensors. In this present study; we outline the recent advances in gas sensors based on MIT; classify and introduce the existing molecularly imprinted gas sensors; summarize their advantages and disadvantages; and analyze further research directions.

  3. Fluorescence based molecular in vivo imaging

    International Nuclear Information System (INIS)

    Ebert, Bernd

    2008-01-01

    Molecular imaging represents a modern research area that allows the in vivo study of molecular biological process kinetics using appropriate probes and visualization methods. This methodology may be defined- apart from the contrast media injection - as non-abrasive. In order to reach an in vivo molecular process imaging as accurate as possible the effects of the used probes on the biological should not be too large. The contrast media as important part of the molecular imaging can significantly contribute to the understanding of molecular processes and to the development of tailored diagnostics and therapy. Since more than 15 years PTB is developing optic imaging systems that may be used for fluorescence based visualization of tissue phantoms, small animal models and the localization of tumors and their predecessors, and for the early recognition of inflammatory processes in clinical trials. Cellular changes occur during many diseases, thus the molecular imaging might be of importance for the early diagnosis of chronic inflammatory diseases. Fluorescent dyes can be used as unspecific or also as specific contrast media, which allow enhanced detection sensitivity

  4. Home-Based versus Hospital-Based Rehabilitation Program after Total Knee Replacement

    Directory of Open Access Journals (Sweden)

    Remedios López-Liria

    2015-01-01

    Full Text Available Objectives. To compare home-based rehabilitation with the standard hospital rehabilitation in terms of improving knee joint mobility and recovery of muscle strength and function in patients after a total knee replacement. Materials and Methods. A non-randomised controlled trial was conducted. Seventy-eight patients with a prosthetic knee were included in the study and allocated to either a home-based or hospital-based rehabilitation programme. Treatment included various exercises to restore strength and joint mobility and to improve patients’ functional capacity. The primary outcome of the trial was the treatment effectiveness measured by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC. Results. The groups did not significantly differ in the leg side (right/left or clinical characteristics (P>0.05. After the intervention, both groups showed significant improvements (P<0.001 from the baseline values in the level of pain (visual analogue scale, the range of flexion-extension motion and muscle strength, disability (Barthel and WOMAC indices, balance, and walking. Conclusions. This study reveals that the rehabilitation treatments offered either at home or in hospital settings are equally effective.

  5. Molecular phylogeny of Ranunculaceae based on internal ...

    African Journals Online (AJOL)

    The botanical family Ranunculaceae contains important medicinal plants. To obtain new evolutionary evidence regarding the systematic classification of Ranunculaceae plants, we used molecular phylogenies to test relationships based on the internal transcribed spacer region. The results of phylogenetic analysis of 92 ...

  6. Molecular phylogeny of Ranunculaceae based on internal ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... The botanical family Ranunculaceae contains important medicinal plants. To obtain new evolutionary evidence regarding the systematic classification of Ranunculaceae plants, we used molecular phylogenies to test relationships based on the internal transcribed spacer region. The results of phylogenetic ...

  7. Environmental Phosphorus Recovery Based on Molecular Bioscavengers

    DEFF Research Database (Denmark)

    Gruber, Mathias Felix

    -scale quantum calculations to macro-scale fluid simulations, are employed to hint at the potential of a recovery technology based on molecular bioscavengers. As a first approach, data mining is used to obtain statistical information about how proteins in nature interact with phosphate groups, thereby revealing...

  8. Evidence-base for aspirin as venous thromboembolic prophylaxis following joint replacement.

    Science.gov (United States)

    Jameson, S S; Baker, P N; Deehan, D J; Port, A; Reed, M R

    2014-05-01

    The National Institute for Health and Clinical Excellence (NICE) has thus far relied on historical data and predominantly industry-sponsored trials to provide evidence for venous thromboembolic (VTE) prophylaxis in joint replacement patients. We argue that the NICE guidelines may be reliant on assumptions that are in need of revision. Following the publication of large scale, independent observational studies showing little difference between low-molecular-weight heparins and aspirin, and recent changes to the guidance provided by other international bodies, should NICE reconsider their recommendations? Cite this article: Bone Joint Res 2014;3:146-9. ©2014 The British Editorial Society of Bone & Joint Surgery.

  9. Graphene-based nanoprobes for molecular diagnostics.

    Science.gov (United States)

    Chen, Shixing; Li, Fuwu; Fan, Chunhai; Song, Shiping

    2015-10-07

    In recent years, graphene has received widespread attention owing to its extraordinary electrical, chemical, optical, mechanical and structural properties. Lately, considerable interest has been focused on exploring the potential applications of graphene in life sciences, particularly in disease-related molecular diagnostics. In particular, the coupling of functional molecules with graphene as a nanoprobe offers an excellent platform to realize the detection of biomarkers, such as nucleic acids, proteins and other bioactive molecules, with high performance. This article reviews emerging graphene-based nanoprobes in electrical, optical and other assay methods and their application in various strategies of molecular diagnostics. In particular, this review focuses on the construction of graphene-based nanoprobes and their special advantages for the detection of various bioactive molecules. Properties of graphene-based materials and their functionalization are also comprehensively discussed in view of the development of nanoprobes. Finally, future challenges and perspectives of graphene-based nanoprobes are discussed.

  10. [Assisted peritoneal dialysis: home-based renal replacement therapy for the elderly patient].

    Science.gov (United States)

    Wiesholzer, Martin

    2013-06-01

    The number of elderly patients with end stage renal disease is constantly increasing. Conventional hämodiaylsis as the mainstay of renal replacement therapy is often poorly tolerated by frail eldery patients with multiple comorbidities. Although many of these patients would prefer a home based dialysis treatment, the number of elderly patients using peritoneal dialysis (PD) is still low. Impaired physical and cognitive function often generates insurmountable barriers for self care peritoneal dialysis. Assisted peritoneal dialysis can overcome many of these barriers and give elderly patients the ability of a renal replacement therapy in their own homes respecting their needs.

  11. Risk-based replacement strategies for redundant deteriorating reinforced concrete pipe networks

    International Nuclear Information System (INIS)

    Adey, B.; Bernard, O.; Gerard, B.

    2003-01-01

    This paper gives an example of how predictive models of the deterioration of reinforced concrete pipes and the consequences of failure can be used to develop risk-based replacement strategies for redundant reinforced concrete pipe networks. It also shows how an accurate deterioration prediction can lead to a reduction of agency costs, and illustrates the limitation of the incremental intervention step algorithm. The main conclusion is that the use of predictive models, such as those developed by Oxand S.A., in the determination of replacement strategies for redundant reinforced concrete pipe networks can lead to a significant reduction in overall costs for the owner of the structure. (author)

  12. Orthonormal Wavelet Bases for Quantum Molecular Dynamics

    International Nuclear Information System (INIS)

    Tymczak, C.; Wang, X.

    1997-01-01

    We report on the use of compactly supported, orthonormal wavelet bases for quantum molecular-dynamics (Car-Parrinello) algorithms. A wavelet selection scheme is developed and tested for prototypical problems, such as the three-dimensional harmonic oscillator, the hydrogen atom, and the local density approximation to atomic and molecular systems. Our method shows systematic convergence with increased grid size, along with improvement on compression rates, thereby yielding an optimal grid for self-consistent electronic structure calculations. copyright 1997 The American Physical Society

  13. Reduction rules-based search algorithm for opportunistic replacement strategy of multiple life-limited parts

    Directory of Open Access Journals (Sweden)

    Xuyun FU

    2018-01-01

    Full Text Available The opportunistic replacement of multiple Life-Limited Parts (LLPs is a problem widely existing in industry. The replacement strategy of LLPs has a great impact on the total maintenance cost to a lot of equipment. This article focuses on finding a quick and effective algorithm for this problem. To improve the algorithm efficiency, six reduction rules are suggested from the perspectives of solution feasibility, determination of the replacement of LLPs, determination of the maintenance occasion and solution optimality. Based on these six reduction rules, a search algorithm is proposed. This search algorithm can identify one or several optimal solutions. A numerical experiment shows that these six reduction rules are effective, and the time consumed by the algorithm is less than 38 s if the total life of equipment is shorter than 55000 and the number of LLPs is less than 11. A specific case shows that the algorithm can obtain optimal solutions which are much better than the result of the traditional method in 10 s, and it can provide support for determining to-be-replaced LLPs when determining the maintenance workscope of an aircraft engine. Therefore, the algorithm is applicable to engineering applications concerning opportunistic replacement of multiple LLPs in aircraft engines.

  14. Replacing Amalgam Restorations: A Standardized Protocol Based on Analyzing Tissue Physicochemical Modifications.

    Science.gov (United States)

    Decup, Franck; Epaillard, Alexandre; Chemla, Florence

    2015-12-01

    Almost 60% of operative dentistry is devoted to replacing restorations. When practitioners have to replace an amalgam restoration, they tend to opt for an adhesive restoration, as it is conservative of tooth tissues and mimics the natural appearance of teeth. Based on a literature review, the aim of this article is to determine the best tissue approach when replacing an old amalgam by a new adhesive restoration. After analyzing and understanding tissue alterations due to the amalgam corrosion process, the authors propose an analytical approach to managing the situation. Both tissue orientated and specific mechanical approaches are developed and should be implemented to carry out the optimal clinical procedure and achieve the most conservative and durable treatment.

  15. A nanoplasmonic switch based on molecular machines

    KAUST Repository

    Zheng, Yue Bing

    2009-06-01

    We aim to develop a molecular-machine-driven nanoplasmonic switch for its use in future nanophotonic integrated circuits (ICs) that have applications in optical communication, information processing, biological and chemical sensing. Experimental data show that an Au nanodisk array, coated with rotaxane molecular machines, switches its localized surface plasmon resonances (LSPR) reversibly when it is exposed to chemical oxidants and reductants. Conversely, bare Au nanodisks and disks coated with mechanically inert control compounds, do not display the same switching behavior. Along with calculations based on time-dependent density functional theory (TDDFT), these observations suggest that the nanoscale movements within surface-bound "molecular machines" can be used as the active components in plasmonic devices. ©2009 IEEE.

  16. Improvement of a new rotation function for molecular replacement by designing new scoring functions and dynamic correlation coefficient

    Science.gov (United States)

    Jiang, Fan; Ding, Wei

    2010-10-01

    A previously published new rotation function has been improved by using a dynamic correlation coefficient as well as two new scoring functions of relative entropy and mean-square-residues to make the rotation function more robust and independent of a specific set of weights for scoring and ranking. The previously described new rotation function calculates the rotation function of molecular replacement by matching the search model directly with the Patterson vector map. The signal-to-noise ratio for the correct match was increased by averaging all the matching peaks. Several matching scores were employed to evaluate the goodness of matching. These matching scores were then combined into a single total score by optimizing a set of weights using the linear regression method. It was found that there exists an optimal set of weights that can be applied to the global rotation search and the correct solution can be ranked in the top 100 or less. However, this set of optimal weights in general is dependent on the search models and the crystal structures with different space groups and cell parameters. In this work, we try to solve this problem by designing a dynamic correlation coefficient. It is shown that the dynamic correlation coefficient works for a variety of space groups and cell parameters in the global search of rotation function. We also introduce two new matching scores: relative entropy and mean-square-residues. Last but not least, we discussed a valid method for the optimization of the adjustable parameters for matching vectors.

  17. Mathematical aspects of molecular replacement. III. Properties of space groups preferred by proteins in the Protein Data Bank.

    Science.gov (United States)

    Chirikjian, G; Sajjadi, S; Toptygin, D; Yan, Y

    2015-03-01

    The main goal of molecular replacement in macromolecular crystallography is to find the appropriate rigid-body transformations that situate identical copies of model proteins in the crystallographic unit cell. The search for such transformations can be thought of as taking place in the coset space Γ\\G where Γ is the Sohncke group of the macromolecular crystal and G is the continuous group of rigid-body motions in Euclidean space. This paper, the third in a series, is concerned with viewing nonsymmorphic Γ in a new way. These space groups, rather than symmorphic ones, are the most common ones for protein crystals. Moreover, their properties impact the structure of the space Γ\\G. In particular, nonsymmorphic space groups contain both Bieberbach subgroups and symmorphic subgroups. A number of new theorems focusing on these subgroups are proven, and it is shown that these concepts are related to the preferences that proteins have for crystallizing in different space groups, as observed in the Protein Data Bank.

  18. Towards the molecular bases of polymerase dynamics

    International Nuclear Information System (INIS)

    Chela Flores, J.

    1991-03-01

    One aspect of the strong relationship that is known to exist between the processes of DNA replication and transcription is manifest in the coupling of the rates of movement of the replication fork (r f ) and RNA polymerase (r t ). We address two issues concerning the largely unexplored area of polymerase dynamics: (i) The validity of an approximate kinematic formula linking r f and r t suggested by experiments in which transcription is initiated in some prokaryotes with the antibiotic streptolydigin, and (ii) What are the molecular bases of the kinematic formula? An analysis of the available data suggests possible molecular bases for polymerase dynamics. In particular, we are led to a hypothesis: In active chromatin r t may depend on the length (λ t ) of the transcript of the primary messenger RNA (pre-mRNA). This new effect is subject to experimental verification. We discuss possible experiments that may be performed in order to test this prediction. (author). Refs, 6 tabs

  19. Replacement of wheat bran with spineless cactus in sugarcane-based diets for steers

    Directory of Open Access Journals (Sweden)

    Maria Gabriela da Conceição

    2016-04-01

    Full Text Available ABSTRACT The effect of replacing wheat bran with spineless cactus (0, 25, 50, 75, and 100% in sugar cane-based diets on the intake of nutrients, feeding behavior, and rumen digestibility of steers was assessed using digested samples collected from the omasum. Five crossbred steers (1/2 Holstein-Zebu were fitted with cannulas in the rumen and then assigned to a 5 × 5 Latin square design. Samples of omasal digesta were collected for three days. Rumen was evacuated via the rumen cannula to determine the rumen pool of dry matter (DM, neutral detergent fiber (NDF, indigestible NDF (iNDF, intake (ki, passage (kp and degradation (NDF rates, and the passage of iNDF (kpi. Nutrient intake displayed a quadratic effect, with maximum intakes of DM (5.73 kg d−1, non-fiber carbohydrates (NFC, 4.63 kg d−1, and digestible organic matter (DOM, 3.45 kg d−1 estimated at the replacement levels of 54.63, 60.00, and 43.17%, respectively. The replacement levels showed no effect on feeding, rumination, or idle times. There was a linear increase in the total apparent and ruminal digestibility of CP as the spineless cactus content in the diet was increased. There was no effect on total and partial digestibilities of OM and NDF or on intestinal digestibility of CP. No effect was observed on the rumen pool of DM, NDF, or iNDF. Furthermore, ki, kp, NDF degradation, and iNDF passage rates displayed a quadratic effect, with higher concentrations estimated for replacement levels of 56.07, 56.12, 59.00, and 55.20%, respectively. Replacing 55% wheat bran with spineless cactus in sugar cane-based diets is recommended.

  20. Replacement of Co-base alloy for radiation exposure reduction in the primary system of PWR

    International Nuclear Information System (INIS)

    Han, Jeong Ho; Nyo, Kye Ho; Lee, Deok Hyun; Lim, Deok Jae; Ahn, Jin Keun; Kim, Sun Jin

    1996-01-01

    Of numerous Co-free alloys developed to replace Co-base stellite used in valve hardfacing material, two iron-base alloys of Armacor M and Tristelle 5183 and one nickel-base alloy of Nucalloy 488 were selected as candidate Co-free alloys, and Stellite 6 was also selected as a standard hardfacing material. These four alloys were welded on 316SS substrate using TIG welding method. The first corrosion test loop of KAERI simulating the water chemistry and operation condition of the primary system of PWR was designed and fabricated. Corrosion behaviors of the above four kinds of alloys were evaluated using this test loop under the condition of 300 deg C, 1500 psi. Microstructures of weldment of these alloys were observed to identify both matrix and secondary phase in each weldment. Hardnesses of weld deposit layer including HAZ and substrate were measured using micro-Vickers hardness tester. The status on the technology of Co-base alloy replacement in valve components was reviewed with respect to the classification of valves to be replaced, the development of Co-free alloys, the application of Co-free alloys and its experiences in foreign NPPs, and the Co reduction program in domestic NPPs and industries. 18 tabs., 20 figs., 22 refs. (Author)

  1. [Efficacy of health education on patients with hip replacement based on the Internet].

    Science.gov (United States)

    Zhou, Yang; Yang, Tubao; Li, Yinglan; Yu, Jie; Zeng, Biyun

    2015-03-01

    To evaluate the efficacy of health education on patients with hip replacement based on the Internet, and to establish a new health education model through modern technology. A total of 300 patients with hip replacement from March to August, 2015 were enrolled in this study. The participants were divided into a control group and an experimental group according to months surgeries performed. Traditional education was applied in the control group while the multimedia source material plus the Internet platform of Joint Registration System were applied in the experimental group. Levels of anxiety, degree of satisfaction, and postoperative complications were analyzed. The levels of knowledge, attitude and behavior compliance in the patients of the experimental group were significantly improved, while the levels of postoperative anxiety were decreased compared with those in the control group (PEducation based on the Internet platform of Joint Registration System and the computer video could improve patients' knowledge, attitude, and behavior, which is worthy of clinical spread.

  2. Cell-based therapeutic strategies for replacement and preservation in retinal degenerative diseases

    Science.gov (United States)

    Jones, Melissa K.; Lu, Bin; Girman, Sergey; Wang, Shaomei

    2017-01-01

    Cell-based therapeutics offer diverse options for treating retinal degenerative diseases, such as age-related macular degeneration (AMD) and retinitis pigmentosa (RP). AMD is characterized by both genetic and environmental risks factors, whereas RP is mainly a monogenic disorder. Though treatments exist for some patients with neovascular AMD, a majority of retinal degenerative patients have no effective therapeutics, thus indicating a need for universal therapies to target diverse patient populations. Two main cell-based mechanistic approaches are being tested in clinical trials. Replacement therapies utilize cell-derived retinal pigment epithelial (RPE) cells to supplant lost or defective host RPE cells. These cells are similar in morphology and function to native RPE cells and can potentially supplant the responsibilities of RPE in vivo. Preservation therapies utilize supportive cells to aid in visual function and photoreceptor preservation partially by neurotrophic mechanisms. The goal of preservation strategies is to halt or slow the progression of disease and maintain remaining visual function. A number of clinical trials are testing the safety of replacement and preservation cell therapies in patients; however, measures of efficacy will need to be further evaluated. In addition, a number of prevailing concerns with regards to the immune-related response, longevity, and functionality of the grafted cells will need to be addressed in future trials. This review will summarize the current status of cell-based preclinical and clinical studies with a focus on replacement and preservation strategies and the obstacles that remain regarding these types of treatments. PMID:28111323

  3. A trivariate optimal replacement policy for a deteriorating system based on cumulative damage and inspections

    International Nuclear Information System (INIS)

    Tsai, Hsin-Nan; Sheu, Shey-Huei; Zhang, Zhe George

    2017-01-01

    In this article, we study a trivariate replacement model for a deteriorating system consisting of two units. Failures of unit 1 can be classified into two types. Type I failure (minor failure) is fixed by a minimal repair and type II failure (catastrophic failure) is removed by a replacement. Both types of failures can only be detected through inspection. Each type I failure of unit 1 will result in a random amount of damage to unit 2 and the damages are cumulative. The probability of type I failure or type II failure is assumed to depend on the number of failures since the last replacement. We formulate a replacement policy based on the number of type I failure, the occurrence of the first type II failure, and the amount of accumulative damages. Hence the system is replaced either preventively or correctively at any of the following four conditions depend on whichever occurs first; preventively (a) at the Nth type I failure; or (b) when the total damage of unit 2 exceeds a pre-specified level Z (but less than the failure level l); and, correctively (c) at the first type II failure; or (d) when the total damage of unit 2 exceeds a failure level l, where Z and l represent the thresholds of total damage level for unit 2 to preventive and corrective replacements, respectively. Although a type I failure can be fixed by a minimal repair, but the operating period is stochastically decreasing and repair time is stochastically increasing as time goes on. The minimal total expected long-run net cost per unit time of the system is derived and a computational algorithm for determining the optimal policy is developed. A real-world application from electric power industry is provided. Several past studied are shown to be special cases of our model. Finally, a numerical example is presented. - Highlights: • A trivariate replacement policy for a deteriorating system with two units is proposed. • A real-world application from the electric power industry is provided. • The

  4. Improvement of a new rotation function for molecular replacement by designing new scoring functions and dynamic correlation coefficient

    International Nuclear Information System (INIS)

    Fan, Jiang; Wei, Ding

    2010-01-01

    A previously published new rotation function has been improved by using a dynamic correlation coefficient as well as two new scoring functions of relative entropy and mean-square-residues to make the rotation function more robust and independent of a specific set of weights for scoring and ranking. The previously described new rotation function calculates the rotation function of molecular replacement by matching the search model directly with the Patterson vector map. The signal-to-noise ratio for the correct match was increased by averaging all the matching peaks. Several matching scores were employed to evaluate the goodness of matching. These matching scores were then combined into a single total score by optimizing a set of weights using the linear regression method. It was found that there exists an optimal set of weights that can be applied to the global rotation search and the correct solution can be ranked in the top 100 or less. However, this set of optimal weights in general is dependent on the search models and the crystal structures with different space groups and cell parameters. In this work, we try to solve this problem by designing a dynamic correlation coefficient. It is shown that the dynamic correlation coefficient works for a variety of space groups and cell parameters in the global search of rotation function. We also introduce two new matching scores: relative entropy and mean-square-residues. Last but not least, we discussed a valid method for the optimization of the adjustable parameters for matching vectors. (condensed matter: structure, thermal and mechanical properties)

  5. As bases moleculares da hemofilia A

    Directory of Open Access Journals (Sweden)

    Simone Ferreira Pio

    2009-01-01

    Full Text Available As hemofilias são doenças hemorrágicas resultantes da deficiência de fator VIII (hemofilia A ou de fator IX (hemofilia B da coagulação, decorrentes de mutações nos genes que codificam os fatores VIII ou IX, respectivamente. A hemofilia A é mais frequente que a hemofilia B e acomete aproximadamente 1:10.000 nascimentos masculinos. A gravidade e frequência dos episódios hemorrágicos está relacionado ao nível residual de atividade de fator VIII presente no plasma e este relaciona-se ao tipo de mutação associada à doença. A clonagem do gene do fator VIII tornou possível o conhecimento das bases moleculares da hemofilia A, sendo hoje conhecidas mais de 1.000 mutações associadas à doença. O conhecimento das bases moleculares da hemofilia A permite uma melhor compreensão da relação genótipo-fenótipo da doença, tomada de condutas clínicas diferenciadas em casos de mutações associadas a um maior risco de desenvolvimento de inibidor, determinação da condição de portadora de hemofilia em mulheres relacionadas aos pacientes, implementação de programa de aconselhamento genético/orientação familiar e melhor compreensão das relações estruturais-funcionais do gene-proteína. Este artigo propõe revisar as bases moleculares da hemofilia A, os métodos laboratoriais utilizados para a caracterização das mutações e as implicações clínicas envolvidas no diagnóstico molecular da hemofilia A.Hemophilias are bleeding disorders due to deficiency of the blood coagulation factor VIII (hemophilia A or factor IX (hemophilia B, resulting from mutation on the gene coding for factor VIII or factor IX. Hemophilia A is more frequent than hemophilia B and affects 1:10,000 male newborns. The severity and frequency of hemorrhagic episodes is related to residual activity of factor VIII present in the plasma and relates to the type of mutation associated with the disorder. Cloning of the factor VIII gene has enabled researchers to

  6. Cost Optimal Reliability Based Inspection and Replacement Planning of Piping Subjected to CO2 Corrosion

    DEFF Research Database (Denmark)

    Hellevik, S. G.; Langen, I.; Sørensen, John Dalsgaard

    1999-01-01

    within the framework of Bayesian decision theory. The planning problem is formulated as an optimization problem where the expected lifetime costs are minimized with a constraint on the minimum acceptable reliability level. The optimization parameters are the number of inspections in the expected lifetime......A methodology for cost optimal reliability based inspection and replacement planning of piping subjected to CO2 corrosion is described. Both initial (design phase) and in-service planning are dealt with. The methodology is based on the application of methods for structural reliability analysis...

  7. Replacement of traditional lectures with computer-based tutorials: a case study

    Directory of Open Access Journals (Sweden)

    Derek Lavelle

    1996-12-01

    Full Text Available This paper reports on a pilot project with a group of 60 second-year undergraduates studying the use of standard forms of contract in the construction industry. The project entailed the replacement of two of a series of nine scheduled lectures with a computer-based tutorial. The two main aims of the project were to test the viability of converting existing lecture material into computer-based material on an in-house production basis, and to obtain feedback from the student cohort on their behavioural response to the change in media. The effect on student performance was not measured at this stage of development.

  8. Effect of early progressive resistance training compared with home-based exercise after total hip replacement

    DEFF Research Database (Denmark)

    Mikkelsen, Lone Ramer; Mechlenburg, Inger; Søballe, Kjeld

    Introduction Muscle strength and physical function deficits persist after total hip replacement (THR). Training effect evidence after THR is lacking. This study investigates the effect of supervised progressive resistance training in early post-THR rehabilitation on muscle strength and functional...... in CG (1.58 [0.8;2.4] sec) (p=0.05). No significant differences were found in stair test; yet, borderline significance (p=0.06-0.09) favoured IG in STS and isometric strength. Conclusion 7 days/week of home-based exercise was just as effective as 5 days/week of home-based exercise plus 2 days...

  9. Single-Dose Lignocaine-Based Blood Cardioplegia in Single Valve Replacement Patients

    Directory of Open Access Journals (Sweden)

    Jaydip Ramani

    Full Text Available Abstract OBJECTIVE: Myocardial protection is the most important in cardiac surgery. We compared our modified single-dose long-acting lignocaine-based blood cardioplegia with short-acting St Thomas 1 blood cardioplegia in patients undergoing single valve replacement. METHODS: A total of 110 patients who underwent single (aortic or mitral valve replacement surgery were enrolled. Patients were divided in two groups based on the cardioplegia solution used. In group 1 (56 patients, long-acting lignocaine based-blood cardioplegia solution was administered as a single dose while in group 2 (54 patients, standard St Thomas IB (short-acting blood-based cardioplegia solution was administered and repeated every 20 minutes. All the patients were compared for preoperative baseline parameters, intraoperative and all the postoperative parameters. RESULTS: We did not find any statistically significant difference in preoperative baseline parameters. Cardiopulmonary bypass time were 73.8±16.5 and 76.4±16.9 minutes (P=0.43 and cross clamp time were 58.9±10.3 and 66.3±11.2 minutes (P=0.23 in group 1 and group 2, respectively. Mean of maximum inotrope score was 6.3±2.52 and 6.1±2.13 (P=0.65 in group 1 and group 2, respectively. We also did not find any statistically significant difference in creatine-phosphokinase-MB (CPK-MB, Troponin-I levels, lactate level and cardiac functions postoperatively. CONCLUSION: This study proves the safety and efficacy of long-acting lignocaine-based single-dose blood cardioplegia compared to the standard short-acting multi-dose blood cardioplegia in patients requiring the single valve replacement. Further studies need to be undertaken to establish this non-inferiority in situations of complex cardiac procedures especially in compromised patients.

  10. Advanced molecular devices based on light-driven molecular motors

    NARCIS (Netherlands)

    Chen, Jiawen

    2015-01-01

    Nature has provided a large collection of molecular machines and devices that are among the most amazing nanostructures on this planet. These machines are able to operate complex biological processes which are of great importance in our organisms. Inspired by these natural devices, artificial

  11. The cytotoxicity of organobismuth compounds with certain molecular structures can be diminished by replacing the bismuth atom with an antimony atom in the molecules.

    Science.gov (United States)

    Kohri, Kumiko; Yoshida, Eiko; Yasuike, Shuji; Fujie, Tomoya; Yamamoto, Chika; Kaji, Toshiyuki

    2015-06-01

    Organic-inorganic hybrid molecules, which are composed of an organic structure and metal(s), are indispensable for synthetic chemical reactions; however, their toxicity has been incompletely understood. In the present study, we discovered two cytotoxic organobismuth compounds whose cytotoxicity diminished upon replacement of the intramolecular bismuth atom with an antimony atom. The intracellular accumulation of the organobismuth compounds was much higher than that of the organoantimony compounds with the corresponding organic structures. We also showed that both the organic structure and bismuth atom are required for certain organobismuth compounds to exert their cytotoxic effect, suggesting that the cytotoxicity of such a compound is a result of an interaction between the organic structure and the bismuth atom. The present data suggest that organobismuth compounds with certain molecular structures exhibit cytotoxicity via an interaction between the molecular structure and the bismuth atom, and this cytotoxicity can be diminished by replacing the bismuth atom with an antimony atom, resulting in lower intracellular accumulation.

  12. Folding of small proteins by Monte Carlo simulations with chemical shift restraints without the use of molecular fragment replacement or structural homology.

    Science.gov (United States)

    Robustelli, Paul; Cavalli, Andrea; Dobson, Christopher M; Vendruscolo, Michele; Salvatella, Xavier

    2009-06-04

    It has recently been shown that protein structures can be determined from nuclear magnetic resonance (NMR) chemical shifts using a molecular fragment replacement strategy. In these approaches, structural motifs are selected from existing protein structures on the basis of chemical shift and sequence homology and assembled to generate new structures. Here, we demonstrate that it is also possible to determine structures of proteins by directly incorporating experimental NMR chemical shifts as structural restraints in conformational searches, without the use of structural homology and molecular fragment replacement. In this approach, a protein is folded from an extended conformation to its native state using a simulated annealing procedure that minimizes an energy function that combines a standard force field with a term that penalizes the differences between experimental and calculated chemical shifts. We provide an initial demonstration of this procedure by determining the structure of two small proteins, with alpha and beta folds, respectively.

  13. Lean body mass-based levothyroxine replacement in young athyrotic patients with differentiated carcinoma of thyroid

    Directory of Open Access Journals (Sweden)

    Fatima Begum

    2013-01-01

    Full Text Available Objective: The objective of this study was to optimize dose of levothyroxine (LT4 based on lean body mass (LBM in young athyrotic patients with differentiated carcinoma of thyroid (DCT which has not been properly addressed in Bangladesh before. Materials and Methods: Sixty patients with DCT (age, range: 20-39 years having total thyroidectomy followed by radioiodine ablative therapy (RIT and 23 euthyroid volunteers were recruited. Clinical, biochemical parameters were obtained from all patients after 2 months of RIT and on LT4 replacement at a dose of 200 μg/day as first follow up visit and also from control subjects. Then 60 patients were divided into two groups consisting of 30 patients each. Patients of Group-I received LT4 replacement based on LBM measured by dual energy X-ray absorptiometry (DXA and Group-II continued LT4 replacement in conventional dose. Patients of both groups were assessed again for same parameters at 6 to 12 months at the second visit. Results: Optimized dose of LT4 based on LBM by DXA (131 ±23 μg/day significantly reduced thyroid hormones and kept thyroid stimulating hormone (TSH in expected levels in patients of Group-I at the second visit compared to patients of Group-II who continued conventional LT4 dose (200 μg/day. Hyperthyroid symptom scale (HSS was significantly reduced to 2 ± 1 in patients of Group-I but not in patients of Group-II, HSS, 8 ±1 ( P < 0.001. Conclusion: Optimization of LT4 dose based on LBM can avoid chronic exposure of mild excess of thyroid hormone in young patients with low risk DCT.

  14. Lean body mass-based levothyroxine replacement in young athyrotic patients with differentiated carcinoma of thyroid

    Science.gov (United States)

    Begum, Fatima; Ahmed, Chaudhury M.; Afroz, Shahana; Kabir, Enamul; Alam, Faridul; Banerjee, Sajal; Zaman, Nazma

    2013-01-01

    Objective: The objective of this study was to optimize dose of levothyroxine (LT4) based on lean body mass (LBM) in young athyrotic patients with differentiated carcinoma of thyroid (DCT) which has not been properly addressed in Bangladesh before. Materials and Methods: Sixty patients with DCT (age, range: 20-39 years) having total thyroidectomy followed by radioiodine ablative therapy (RIT) and 23 euthyroid volunteers were recruited. Clinical, biochemical parameters were obtained from all patients after 2 months of RIT and on LT4 replacement at a dose of 200 μg/day as first follow up visit and also from control subjects. Then 60 patients were divided into two groups consisting of 30 patients each. Patients of Group-I received LT4 replacement based on LBM measured by dual energy X-ray absorptiometry (DXA) and Group-II continued LT4 replacement in conventional dose. Patients of both groups were assessed again for same parameters at 6 to 12 months at the second visit. Results: Optimized dose of LT4 based on LBM by DXA (131 ±23 μg/day) significantly reduced thyroid hormones and kept thyroid stimulating hormone (TSH) in expected levels in patients of Group-I at the second visit compared to patients of Group-II who continued conventional LT4 dose (200 μg/day). Hyperthyroid symptom scale (HSS) was significantly reduced to 2 ± 1 in patients of Group-I but not in patients of Group-II, HSS, 8 ±1 (P > 0.001). Conclusion: Optimization of LT4 dose based on LBM can avoid chronic exposure of mild excess of thyroid hormone in young patients with low risk DCT. PMID:23776898

  15. Finite Element Analysis of Influence of Axial Position of Center of Rotation of a Cervical Total Disc Replacement on Biomechanical Parameters: Simulated 2-Level Replacement Based on a Validated Model.

    Science.gov (United States)

    Li, Yang; Zhang, Zhenjun; Liao, Zhenhua; Mo, Zhongjun; Liu, Weiqiang

    2017-10-01

    Finite element models have been widely used to predict biomechanical parameters of the cervical spine. Previous studies investigated the influence of position of rotational centers of prostheses on cervical biomechanical parameters after 1-level total disc replacement. The purpose of this study was to explore the effects of axial position of rotational centers of prostheses on cervical biomechanics after 2-level total disc replacement. A validated finite element model of C3-C7 segments and 2 prostheses, including the rotational center located at the superior endplate (SE) and inferior endplate (IE), was developed. Four total disc replacement models were used: 1) IE inserted at C4-C5 disc space and IE inserted at C5-C6 disc space (IE-IE), 2) IE-SE, 3) SE-IE, and 4) SE-SE. All models were subjected to displacement control combined with a 50 N follower load to simulate flexion and extension motions in the sagittal plane. For each case, biomechanical parameters, including predicted moments, range of rotation at each level, facet joint stress, and von Mises stress on the ultra-high-molecular-weight polyethylene core of the prostheses, were calculated. The SE-IE model resulted in significantly lower stress at the cartilage level during extension and at the ultra-high-molecular-weight polyethylene cores when compared with the SE-SE construct and did not generate hypermotion at the C4-C5 level compared with the IE-SE and IE-IE constructs. Based on the present analysis, the SE-IE construct is recommended for treating cervical disease at the C4-C6 level. This study may provide a useful model to inform clinical operations. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Old fold in a new X-ray diffraction dataset? Low-resolution molecular replacement using representative structural templates can provide phase information.

    Science.gov (United States)

    Rajavel, M; Warrier, Thulasi; Gopal, B

    2006-09-01

    The advent of structural genomics has led to a dramatic increase in the number of structures deposited in the Protein Data Bank. The number of new folds, however, still remains a very small fraction of the total number of deposited structures. Recent data on the progress of the structural genomics initiative reveals that more than 85% of target proteins that progress to the stage of data collection and structure determination have a known fold. Enzymes, which tend to exploit reaction space while adopting a common stable scaffold, contribute significantly to this observation. Herein, we evaluate a method to examine the "old fold in a new dataset" scenario likely to be encountered in the structural genomics pipeline. We demonstrate that a fold detection strategy based on secondary structure signatures followed by molecular replacement using a minimalist model can be effectively used to solve the phase problem in X-ray crystallography without further recourse to heavy atom derivatives or multiple anomalous dispersion techniques. Three common folds-the triosephosphate isomerase (TIM), adenine nucleotide alpha hydrolase-like (HUP), and RNA recognition motif (RRM)-were examined using this approach. The results presented herein also provide an estimate of the extent of phase information that can be derived from a single domain in a large multidomain structure. (c) 2006 Wiley-Liss, Inc.

  17. Monocular Vision- and IMU-Based System for Prosthesis Pose Estimation During Total Hip Replacement Surgery.

    Science.gov (United States)

    Su, Shaojie; Zhou, Yixin; Wang, Zhihua; Chen, Hong

    2017-06-01

    The average age of population increases worldwide, so does the number of total hip replacement surgeries. Total hip replacement, however, often involves a risk of dislocation and prosthetic impingement. To minimize the risk after surgery, we propose an instrumented hip prosthesis that estimates the relative pose between prostheses intraoperatively and ensures the placement of prostheses within a safe zone. We create a model of the hip prosthesis as a ball and socket joint, which has four degrees of freedom (DOFs), including 3-DOF rotation and 1-DOF translation. We mount a camera and an inertial measurement unit (IMU) inside the hollow ball, or "femoral head prosthesis," while printing customized patterns on the internal surface of the socket, or "acetabular cup." Since the sensors were rigidly fixed to the femoral head prosthesis, measuring its motions poses a sensor ego-motion estimation problem. By matching feature points in images of the reference patterns, we propose a monocular vision based method with a relative error of less than 7% in the 3-DOF rotation and 8% in the 1-DOF translation. Further, to reduce system power consumption, we apply the IMU with its data fused by an extended Kalman filter to replace the camera in the 3-DOF rotation estimation, which yields a less than 4.8% relative error and a 21.6% decrease in power consumption. Experimental results show that the best approach to prosthesis pose estimation is a combination of monocular vision-based translation estimation and IMU-based rotation estimation, and we have verified the feasibility and validity of this system in prosthesis pose estimation.

  18. Prevention of deep vein thrombosis after hip replacement: randomised comparison between unfractionated heparin and low molecular weight heparin

    NARCIS (Netherlands)

    Leyvraz, P. F.; Bachmann, F.; Hoek, J.; Büller, H. R.; Postel, M.; Samama, M.; Vandenbroek, M. D.

    1991-01-01

    To evaluate the efficacy and safety of two subcutaneous prophylactic regimens for postoperative deep vein thrombosis after total hip replacement. Prospective open randomised multicentre trial. 28 European departments of orthopaedic surgery. All patients had bilateral phlebography 10 days after

  19. Survey of Canadian Animal-Based Researchers' Views on the Three Rs: Replacement, Reduction and Refinement

    Science.gov (United States)

    Fenwick, Nicole; Danielson, Peter; Griffin, Gilly

    2011-01-01

    The ‘Three Rs’ tenet (replacement, reduction, refinement) is a widely accepted cornerstone of Canadian and international policies on animal-based science. The Canadian Council on Animal Care (CCAC) initiated this web-based survey to obtain greater understanding of ‘principal investigators’ and ‘other researchers’ (i.e. graduate students, post-doctoral researchers etc.) views on the Three Rs, and to identify obstacles and opportunities for continued implementation of the Three Rs in Canada. Responses from 414 participants indicate that researchers currently do not view the goal of replacement as achievable. Researchers prefer to use enough animals to ensure quality data is obtained rather than using the minimum and potentially waste those animals if a problem occurs during the study. Many feel that they already reduce animal numbers as much as possible and have concerns that further reduction may compromise research. Most participants were ambivalent about re-use, but expressed concern that the practice could compromise experimental outcomes. In considering refinement, many researchers feel there are situations where animals should not receive pain relieving drugs because it may compromise scientific outcomes, although there was strong support for the Three Rs strategy of conducting animal welfare-related pilot studies, which were viewed as useful for both animal welfare and experimental design. Participants were not opposed to being offered “assistance” to implement the Three Rs, so long as the input is provided in a collegial manner, and from individuals who are perceived as experts. It may be useful for animal use policymakers to consider what steps are needed to make replacement a more feasible goal. In addition, initiatives that offer researchers greater practical and logistical support with Three Rs implementation may be useful. Encouragement and financial support for Three Rs initiatives may result in valuable contributions to Three Rs

  20. Survey of Canadian animal-based researchers' views on the Three Rs: replacement, reduction and refinement.

    Directory of Open Access Journals (Sweden)

    Nicole Fenwick

    Full Text Available The 'Three Rs' tenet (replacement, reduction, refinement is a widely accepted cornerstone of Canadian and international policies on animal-based science. The Canadian Council on Animal Care (CCAC initiated this web-based survey to obtain greater understanding of 'principal investigators' and 'other researchers' (i.e. graduate students, post-doctoral researchers etc. views on the Three Rs, and to identify obstacles and opportunities for continued implementation of the Three Rs in Canada. Responses from 414 participants indicate that researchers currently do not view the goal of replacement as achievable. Researchers prefer to use enough animals to ensure quality data is obtained rather than using the minimum and potentially waste those animals if a problem occurs during the study. Many feel that they already reduce animal numbers as much as possible and have concerns that further reduction may compromise research. Most participants were ambivalent about re-use, but expressed concern that the practice could compromise experimental outcomes. In considering refinement, many researchers feel there are situations where animals should not receive pain relieving drugs because it may compromise scientific outcomes, although there was strong support for the Three Rs strategy of conducting animal welfare-related pilot studies, which were viewed as useful for both animal welfare and experimental design. Participants were not opposed to being offered "assistance" to implement the Three Rs, so long as the input is provided in a collegial manner, and from individuals who are perceived as experts. It may be useful for animal use policymakers to consider what steps are needed to make replacement a more feasible goal. In addition, initiatives that offer researchers greater practical and logistical support with Three Rs implementation may be useful. Encouragement and financial support for Three Rs initiatives may result in valuable contributions to Three Rs

  1. Survey of Canadian animal-based researchers' views on the Three Rs: replacement, reduction and refinement.

    Science.gov (United States)

    Fenwick, Nicole; Danielson, Peter; Griffin, Gilly

    2011-01-01

    The 'Three Rs' tenet (replacement, reduction, refinement) is a widely accepted cornerstone of Canadian and international policies on animal-based science. The Canadian Council on Animal Care (CCAC) initiated this web-based survey to obtain greater understanding of 'principal investigators' and 'other researchers' (i.e. graduate students, post-doctoral researchers etc.) views on the Three Rs, and to identify obstacles and opportunities for continued implementation of the Three Rs in Canada. Responses from 414 participants indicate that researchers currently do not view the goal of replacement as achievable. Researchers prefer to use enough animals to ensure quality data is obtained rather than using the minimum and potentially waste those animals if a problem occurs during the study. Many feel that they already reduce animal numbers as much as possible and have concerns that further reduction may compromise research. Most participants were ambivalent about re-use, but expressed concern that the practice could compromise experimental outcomes. In considering refinement, many researchers feel there are situations where animals should not receive pain relieving drugs because it may compromise scientific outcomes, although there was strong support for the Three Rs strategy of conducting animal welfare-related pilot studies, which were viewed as useful for both animal welfare and experimental design. Participants were not opposed to being offered "assistance" to implement the Three Rs, so long as the input is provided in a collegial manner, and from individuals who are perceived as experts. It may be useful for animal use policymakers to consider what steps are needed to make replacement a more feasible goal. In addition, initiatives that offer researchers greater practical and logistical support with Three Rs implementation may be useful. Encouragement and financial support for Three Rs initiatives may result in valuable contributions to Three Rs knowledge and improve

  2. Hypophosphatemia on the intensive care unit: individualized phosphate replacement based on serum levels and distribution volume.

    NARCIS (Netherlands)

    Bech, A.P.; Blans, M.; Raaijmakers, M.H.G.P.; Mulkens, C.; Telting, D.; Boer, H. de

    2013-01-01

    BACKGROUND: Hypophosphatemia occurs in about 25% of patients admitted to the intensive care unit. To date, a safe and validated phosphate replacement protocol is not available. OBJECTIVE: To evaluate an individualized phosphate replacement regimen. DESIGN: Fifty consecutive intensive care unit

  3. Penentuan Interval Waktu Penggantian Optimal Komponen Berdasarkan Model Opportunity Based-Age Replacement

    OpenAIRE

    Giatman, Muhammad

    2008-01-01

    Maintenance system, especially replacement that is not good, can cause much lose out for the company. The lose out is caused production process disturbing bay unexpectadly or unscheduled replacement. This will lose out for factory that have continue flow shop type, because replacement of the component that is need shut down machine will cause all machine in the process production stop. To anticipate of lose out that cause by replacement activity, so in this research will search interval of op...

  4. Condition-Based Conveyor Belt Replacement Strategy in Lignite Mines with Random Belt Deterioration

    Science.gov (United States)

    Blazej, Ryszard; Jurdziak, Leszek

    2017-12-01

    In Polish lignite surface mines, condition-based belt replacement strategies are applied in order to assure profitable refurbishment of worn out belts performed by external firms specializing in belt maintenance. In two of three lignite mines, staff asses belt condition subjectively during visual inspections. Only one mine applies specialized diagnostic device (HRDS) allowing objective magnetic evaluation of belt core condition in order to choose the most profitable moment for the dismantling of worn out belt segments from conveyors and sending them to the maintenance firm which provides their refurbishment. This article describes the advantages of a new diagnostic device called DiagBelt. It was developed at the Faculty of Geoengineering, Mining and Geology, Wroclaw University of Science and Technology. Economic gains from its application are calculated for the lignite mine and for the belt maintenance firm, taking into account random life (durability) of new and reconditioned belts (after the 1st and the 2nd refurbishment). Recursive calculations for following years allow the estimation of the length and costs of replaced, reconditioned and purchased belts on an annual basis, while the use of the Monte Carlo method allows the estimation of their variability caused by random deterioration of belts. Savings are obtained due to better selection of moments (times) for the replacement of belt segments and die to the possibility to qualify worn out belts for refurbishment without the need to remove their covers. In effect, increased belt durability and lowered share of waste belts (which were not qualified for reconditioning) create savings which can quickly cover expenditures on new diagnostic tools and regular belt inspections in the mine.

  5. Allogeneic blood transfusion and prognosis following total hip replacement: a population-based follow up study

    DEFF Research Database (Denmark)

    Pedersen, Alma B; Mehnert, Frank; Overgaard, Søren

    2009-01-01

    BACKGROUND: Allogeneic red blood cell transfusion is frequently used in total hip replacement surgery (THR). However, data on the prognosis of transfused patients are sparse. In this study we compared the risk of complications following THR in transfused and non-transfused patients. METHODS......: A population-based follow-up study was performed using data from medical databases in Denmark. We identified 28,087 primary THR procedures performed from 1999 to 2007, from which we computed a propensity score for red blood cell transfusion based on detailed data on patient-, procedure-, and hospital......-related characteristics. We were able to match 2,254 transfused with 2,254 non-transfused THR patients using the propensity score. RESULTS: Of the 28,087 THR patients, 9,063 (32.3%) received at least one red blood cell transfusion within 8 days of surgery. Transfused patients had higher 90-day mortality compared...

  6. From electrochemical biosensors to biomimetic sensors based on molecularly imprinted polymers in environmental determination of heavy metals

    Science.gov (United States)

    Malitesta, Cosimino; Di Masi, Sabrina; Mazzotta, Elisabetta

    2017-07-01

    Recent work relevant to heavy metal determination by inhibition-enzyme electrochemical biosensors and by selected biomimetic sensors based on molecularly imprinted polymers has been reviewed. General features and peculiar aspects have been evidenced. The replace of biological component by artificial receptors promises higher selectivity and stability, while biosensors keep their capability of producing an integrated response directly related to toxicity of the samples.

  7. Prevention of deep vein thrombosis after hip replacement--comparison between two low-molecular heparins, tinzaparin and enoxaparin

    NARCIS (Netherlands)

    Planès, A.; Samama, M. M.; Lensing, A. W.; Büller, H. R.; Barre, J.; Vochelle, N.; Beau, B.

    1999-01-01

    Consecutive patients undergoing total hip replacement in 43 centres were randomly assigned to receive blindly either enoxaparin (40 mg) or tinzaparin (4,500 anti-Factor IU Xa), as once daily subcutaneous injections. The first injection was administered 12 h preoperatively. Efficacy was assessed by

  8. Comparison of one-step and sequentially irradiated ultrahigh-molecular-weight polyethylene for total joint replacements

    Czech Academy of Sciences Publication Activity Database

    Šlouf, Miroslav; Kotek, Jiří; Baldrian, Josef; Kovářová, Jana; Fencl, J.; Bouda, T.; Janigová, I.

    101B, č. 3 (2013), s. 414-422 ISSN 1552-4973 R&D Projects: GA TA ČR TA01011406; GA MZd NT12229 Institutional research plan: CEZ:AV0Z40500505 Keywords : polyethylene (UHMWPE) * joint replacement * mechanical properties Subject RIV: FI - Traumatology, Orthopedics Impact factor: 2.328, year: 2013

  9. Molecularly Imprinted Polymer/Metal Organic Framework Based Chemical Sensors

    Directory of Open Access Journals (Sweden)

    Zhenzhong Guo

    2016-10-01

    Full Text Available The present review describes recent advances in the concept of molecular imprinting using metal organic frameworks (MOF for development of chemical sensors. Two main strategies regarding the fabrication, performance and applications of recent sensors based on molecularly imprinted polymers associated with MOF are presented: molecularly imprinted MOF films and molecularly imprinted core-shell nanoparticles using MOF as core. The associated transduction modes are also discussed. A brief conclusion and future expectations are described herein.

  10. Handbook of camera monitor systems the automotive mirror-replacement technology based on ISO 16505

    CERN Document Server

    2016-01-01

    This handbook offers a comprehensive overview of Camera Monitor Systems (CMS), ranging from the ISO 16505-based development aspects to practical realization concepts. It offers readers a wide-ranging discussion of the science and technology of CMS as well as the human-interface factors of such systems. In addition, it serves as a single reference source with contributions from leading international CMS professionals and academic researchers. In combination with the latest version of UN Regulation No. 46, the normative framework of ISO 16505 permits CMS to replace mandatory rearview mirrors in series production vehicles. The handbook includes scientific and technical background information to further readers’ understanding of both of these regulatory and normative texts. It is a key reference in the field of automotive CMS for system designers, members of standardization and regulation committees, engineers, students and researchers.

  11. Radar Scan Strategies for the Patrick Air Force Base Weather Surveillance Radar, Model-74C, Replacement

    Science.gov (United States)

    Short, David

    2008-01-01

    The 45th Weather Squadron (45 WS) is replacing the Weather Surveillance Radar, Model 74C (WSR-74C) at Patrick Air Force Base (PAFB), with a Doppler, dual polarization radar, the Radtec 43/250. A new scan strategy is needed for the Radtec 43/250, to provide high vertical resolution data over the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) launch pads, while taking advantage of the new radar's advanced capabilities for detecting severe weather phenomena associated with convection within the 45 WS area of responsibility. The Applied Meteorology Unit (AMU) developed several scan strategies customized for the operational needs of the 45 WS. The AMU also developed a plan for evaluating the scan strategies in the period prior to operational acceptance, currently scheduled for November 2008.

  12. Replacing SUs with incretin-based therapies for type 2 diabetes mellitus: challenges and feasibility

    DEFF Research Database (Denmark)

    Knop, Filip K; Holst, Jens Juul; Vilsbøll, Tina

    2008-01-01

    , these effects result in hyperglycemia. In 1958, sulfonylurea (SU) was introduced to the market as one of the first oral treatments for T2DM. Since then, the ability of SU to stimulate the release of insulin from pancreatic beta-cells by the closure of ATP-sensitive K+-channels has been employed as one...... of the most widespread treatment options for T2DM. However, SUs are associated with weight gain and a risk of hypoglycemia, and the one-track antidiabetic mechanism of SUs often results in patients being treated with additional antidiabetic drugs. In recent studies, SU has proven to be associated...... with increased beta-cell apoptosis, suggesting that SU may actually accelerate the progressive decrease in beta-cell mass, thereby promoting the need for insulin replacement. In contrast, the newly developed incretin-based therapies for T2DM employ the beta-cell-preserving properties of incretin hormones...

  13. A DNA sequence obtained by replacement of the dopamine RNA aptamer bases is not an aptamer

    DEFF Research Database (Denmark)

    Álvarez-Martos, Isabel; Ferapontova, Elena

    2017-01-01

    A unique specificity of the aptamer-ligand biorecognition and binding facilitates bioanalysis and biosensor development, contributing to discrimination of structurally related molecules, such as dopamine and other catecholamine neurotransmitters. The aptamer sequence capable of specific binding...... of dopamine is a 57 nucleotides long RNA sequence reported in 1997 (Biochemistry, 1997, 36, 9726). Later, it was suggested that the DNA homologue of the RNA aptamer retains the specificity of dopamine binding (Biochem. Biophys. Res. Commun., 2009, 388, 732). Here, we show that the DNA sequence obtained...... by the replacement of the RNA aptamer bases for their DNA analogues is not able of specific biorecognition of dopamine, in contrast to the original RNA aptamer sequence. This DNA sequence binds dopamine and structurally related catecholamine neurotransmitters non-specifically, as any DNA sequence, and, thus...

  14. Solid-state-based laser system as a replacement for Ar+ lasers.

    Science.gov (United States)

    Beck, Tobias; Rein, Benjamin; Sörensen, Fabian; Walther, Thomas

    2016-09-15

    We report on a solid-state-based laser system at 1028 nm. The light is generated by a diode laser seeded ytterbium fiber amplifier. In two build-up cavities, its frequency is doubled and quadrupled to 514 nm and 257 nm, respectively. At 514 nm, the system delivers up to 4.7 W of optical power. In the fourth harmonic, up to 173 mW are available limited by the nonlinear crystal. The frequency of the laser is mode-hop-free tunable by 16 GHz in 10 ms in the UV. Therefore, the system is suitable as a low maintenance, efficient, and tunable narrowband replacement for frequency doubled Ar+ laser systems.

  15. Semifragile Speech Watermarking Based on Least Significant Bit Replacement of Line Spectral Frequencies

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Nematollahi

    2017-01-01

    Full Text Available There are various techniques for speech watermarking based on modifying the linear prediction coefficients (LPCs; however, the estimated and modified LPCs vary from each other even without attacks. Because line spectral frequency (LSF has less sensitivity to watermarking than LPC, watermark bits are embedded into the maximum number of LSFs by applying the least significant bit replacement (LSBR method. To reduce the differences between estimated and modified LPCs, a checking loop is added to minimize the watermark extraction error. Experimental results show that the proposed semifragile speech watermarking method can provide high imperceptibility and that any manipulation of the watermark signal destroys the watermark bits since manipulation changes it to a random stream of bits.

  16. Stem Cell Therapy: Repurposing Cell-Based Regenerative Medicine Beyond Cell Replacement.

    Science.gov (United States)

    Napoli, Eleonora; Lippert, Trenton; Borlongan, Cesar V

    2018-02-27

    Stem cells exhibit simple and naive cellular features, yet their exact purpose for regenerative medicine continues to elude even the most elegantly designed research paradigms from developmental biology to clinical therapeutics. Based on their capacity to divide indefinitely and their dynamic differentiation into any type of tissue, the advent of transplantable stem cells has offered a potential treatment for aging-related and injury-mediated diseases. Recent laboratory evidence has demonstrated that transplanted human neural stem cells facilitate endogenous reparative mechanisms by initiating multiple regenerative processes in the brain neurogenic areas. Within these highly proliferative niches reside a myriad of potent regenerative molecules, including anti-inflammatory cytokines, proteomes, and neurotrophic factors, altogether representing a biochemical cocktail vital for restoring brain function in the aging and diseased brain. Here, we advance the concept of therapeutically repurposing stem cells not towards cell replacement per se, but rather exploiting the cells' intrinsic properties to serve as the host brain regenerative catalysts.

  17. Residue contacts predicted by evolutionary covariance extend the application of ab initio molecular replacement to larger and more challenging protein folds.

    Science.gov (United States)

    Simkovic, Felix; Thomas, Jens M H; Keegan, Ronan M; Winn, Martyn D; Mayans, Olga; Rigden, Daniel J

    2016-07-01

    For many protein families, the deluge of new sequence information together with new statistical protocols now allow the accurate prediction of contacting residues from sequence information alone. This offers the possibility of more accurate ab initio (non-homology-based) structure prediction. Such models can be used in structure solution by molecular replacement (MR) where the target fold is novel or is only distantly related to known structures. Here, AMPLE, an MR pipeline that assembles search-model ensembles from ab initio structure predictions ('decoys'), is employed to assess the value of contact-assisted ab initio models to the crystallographer. It is demonstrated that evolutionary covariance-derived residue-residue contact predictions improve the quality of ab initio models and, consequently, the success rate of MR using search models derived from them. For targets containing β-structure, decoy quality and MR performance were further improved by the use of a β-strand contact-filtering protocol. Such contact-guided decoys achieved 14 structure solutions from 21 attempted protein targets, compared with nine for simple Rosetta decoys. Previously encountered limitations were superseded in two key respects. Firstly, much larger targets of up to 221 residues in length were solved, which is far larger than the previously benchmarked threshold of 120 residues. Secondly, contact-guided decoys significantly improved success with β-sheet-rich proteins. Overall, the improved performance of contact-guided decoys suggests that MR is now applicable to a significantly wider range of protein targets than were previously tractable, and points to a direct benefit to structural biology from the recent remarkable advances in sequencing.

  18. Residue contacts predicted by evolutionary covariance extend the application of ab initio molecular replacement to larger and more challenging protein folds

    Directory of Open Access Journals (Sweden)

    Felix Simkovic

    2016-07-01

    Full Text Available For many protein families, the deluge of new sequence information together with new statistical protocols now allow the accurate prediction of contacting residues from sequence information alone. This offers the possibility of more accurate ab initio (non-homology-based structure prediction. Such models can be used in structure solution by molecular replacement (MR where the target fold is novel or is only distantly related to known structures. Here, AMPLE, an MR pipeline that assembles search-model ensembles from ab initio structure predictions (`decoys', is employed to assess the value of contact-assisted ab initio models to the crystallographer. It is demonstrated that evolutionary covariance-derived residue–residue contact predictions improve the quality of ab initio models and, consequently, the success rate of MR using search models derived from them. For targets containing β-structure, decoy quality and MR performance were further improved by the use of a β-strand contact-filtering protocol. Such contact-guided decoys achieved 14 structure solutions from 21 attempted protein targets, compared with nine for simple Rosetta decoys. Previously encountered limitations were superseded in two key respects. Firstly, much larger targets of up to 221 residues in length were solved, which is far larger than the previously benchmarked threshold of 120 residues. Secondly, contact-guided decoys significantly improved success with β-sheet-rich proteins. Overall, the improved performance of contact-guided decoys suggests that MR is now applicable to a significantly wider range of protein targets than were previously tractable, and points to a direct benefit to structural biology from the recent remarkable advances in sequencing.

  19. Potentiality Prediction of Electric Power Replacement Based on Power Market Development Strategy

    Science.gov (United States)

    Miao, Bo; Yang, Shuo; Liu, Qiang; Lin, Jingyi; Zhao, Le; Liu, Chang; Li, Bin

    2017-05-01

    The application of electric power replacement plays an important role in promoting the development of energy conservation and emission reduction in our country. To exploit the potentiality of regional electric power replacement, the regional GDP (gross domestic product) and energy consumption are taken as potentiality evaluation indicators. The principal component factors are extracted with PCA (principal component analysis), and the integral potentiality analysis is made to the potentiality of electric power replacement in the national various regions; a region is taken as a research object, and the potentiality of electric power replacement is defined and quantified. The analytical model for the potentiality of multi-scenario electric power replacement is developed, and prediction is made to the energy consumption with the grey prediction model. The relevant theoretical research is utilized to realize prediction analysis on the potentiality amount of multi-scenario electric power replacement.

  20. Replacing fossil based plastic performance products by bio-based plastic products-Technical feasibility

    NARCIS (Netherlands)

    Oever, van den Martien; Molenveld, Karin

    2017-01-01

    Larger scale market introduction of new bio-based products requires a clear advantage regarding sustainability, as well as an adequate techno-economic positioning relative to fossil based products. In a previous paper [Broeren et al., 2016], LCA results per kg and per functionality equivalent of

  1. Ankle replacement

    Science.gov (United States)

    Ankle arthroplasty - total; Total ankle arthroplasty; Endoprosthetic ankle replacement; Ankle surgery ... Ankle replacement surgery is most often done while you are under general anesthesia. This means you will ...

  2. The acid-base effects of continuous hemofiltration with lactate or bicarbonate buffered replacement fluids.

    Science.gov (United States)

    Tan, H K; Uchino, S; Bellomo, R

    2003-06-01

    To evaluate, quantify and compare the effects of continuous veno-venous hemofiltration (CVVH) with lactate or bicarbonate-buffered replacement fluids on acid-base balance. Randomized double crossover study. Intensive Care Unit of Tertiary Medical Center. Eight patients with severe acute renal failure. Random allocation to either 2 hours of isovolemic lactate-buffered (treatment A) CVVH or 2 hours of bicarbonate-buffered (treatment B) CVVH with cross over and with same procedure repeated the following day (double cross over). Timed collections of arterial blood and ultrafiltrate (UF), measurement of blood and UF gases and lactate concentrations and calculation of buffer-base mass balance. At baseline, both groups of patients had a similar, slight metabolic alkalosis (pH: 7.45 vs. 7.45; BE 3.9 mEq/L for treatment A and 4.0 for treatment B) and a serum bicarbonate of 28.1 mmol/L for treatment A vs. 28.3 mmol/L for treatment B; all NS. This alkalosis was present despite slight hyperlactatemia in both groups (A: 2.4 mmol/L vs. B 2.8 mmol/; NS). Within 60 minutes of treatment, however, treatment A led to a significantly higher lactate concentration (3.9 vs 2.5 mmol/L; p = 0.0011), a significantly lower BE (2.3 vs 4.1 mEq/L; p = 0.0019) and a significantly lower bicarbonate concentration (26.7 vs. 28.3 mmol/L; p = 0.0038) in the presence of an unchanged PaCO2. These differences persisted during the study period. The UF of patients receiving treatment A contained more lactate (10.2 vs 2.9 mmol/L; p buffer-base balance of +20.4 mEq/h compared to -2.6 mEq/h for treatment B; p buffered replacement fluids induces iatrogenic hyperlactatemia. Such hyperlactatemia is associated with an acidifying effect despite a positive buffer-base balance.

  3. VH Replacement Footprint Analyser-I (VHRFA-I, a Java based Computer Program for Analyses of Immunoglobulin Heavy Chain Genes and Potential VH Replacement Products in Human and Mouse

    Directory of Open Access Journals (Sweden)

    Lin eHuang

    2014-02-01

    Full Text Available VH replacement occurs through RAG-mediated secondary recombination between a rearranged VH gene and an upstream unrearranged VH gene. Due to the location of the cryptic Recombination Signal Sequence (cRSS, TACTGTG at the 3’ end of VH gene coding region, a short stretch of nucleotides from the previous rearranged VH gene can be retained in the newly formed VH-DH junction as a footprint of VH replacement. Such footprints can be used as markers to identify IgH genes potentially generated through VH replacement. To explore the contribution of VH replacement products to the antibody repertoire, we developed a Java based computer program, VH replacement footprint analyzer-I (VHRFA-I, to analyze published or newly obtained IgH genes from human or mouse. The VHRFA-1 program has multiple functional modules: it first uses service provided by the IMGT/V-QUEST program to assign potential VH, DH, and JH germline genes; then, it searches for VH replacement footprint motifs within the VH-DH junction (N1 regions of IgH gene sequences to identify potential VH replacement products; it can also analyze the frequencies of VH replacement products in correlation with publications, keywords, or VH, DH, and JH gene usages, and mutation status; it can further analyze the amino acid usages encoded by the identified VH replacement footprints. In summary, this program provides a useful computation tool for exploring the biological significance of VH replacement products in human and mouse.

  4. Nicotine replacement therapy decision based on fuzzy multi-criteria analysis

    Science.gov (United States)

    Tarmudi, Zamali; Matmali, Norfazillah; Abdullah, Mohd Lazim

    2017-08-01

    It has been observed that Nicotine Replacement Therapy (NRT) is one of the alternatives to control and reduce smoking addiction among smokers. Since the decision to choose the best NRT alternative involves uncertainty, ambiguity factors and diverse input datasets, thus, this paper proposes a fuzzy multi-criteria analysis (FMA) to overcome these issues. It focuses on how the fuzzy approach can unify the diversity of datasets based on NRT's decision-making problem. The analysis done employed the advantage of the cost-benefit criterion to unify the mixture of dataset input. The performance matrix was utilised to derive the performance scores. An empirical example regarding the NRT's decision-making problem was employed to illustrate the proposed approach. Based on the calculations, this analytical approach was found to be highly beneficial in terms of usability. It was also very applicable and efficient in dealing with the mixture of input datasets. Hence, the decision-making process can easily be used by experts and patients who are interested to join the therapy/cessation program.

  5. Development of Low-Fat Soft Dough Biscuits Using Carbohydrate-Based Fat Replacers

    Directory of Open Access Journals (Sweden)

    Bhawna Chugh

    2013-01-01

    Full Text Available Experiments were conducted to develop low-fat soft dough biscuits using carbohydrate-based fat replacers (maltodextrin and guar gum. A central composite rotatable design was used to optimise the level of sugar 24–36%, composite fat (fat 10.5–24.5%, maltodextrin 10.4–24%, and guar gum 0.1–0.5%, ammonium bicarbonate 0.5–2.5%, and water 20–24% for production of low-fat biscuits. Diameter and stress-strain ratio decreased significantly with increase in the amount of sugar. There was a significant decrease in spread ratio at high amount of water. Hardness was significantly affected by the interactions of ammonium bicarbonate with sugar and fat . The optimum level of ingredients obtained for low-fat biscuits was sugar 31.7 g, fat 13.55 g, maltodextrin 21.15 g, guar gum 0.3 g, ammonium bicarbonate 2.21 g, and water 21 mL based on 100 g flour. The fat level in the optimised low-fat biscuit formulation was found to be 8.48% as compared to 22.65% in control; therefore, the reduction in fat was 62.5%.

  6. Replacing PS controls front end minicomputers by VME based 32-bit processors

    International Nuclear Information System (INIS)

    Gagnaire, A.; Metz Noblat, N. de; Serre, Ch.; Sicard, Cl.H.

    1992-01-01

    The PS controls have started the first phase of system rejuvenation, targeted towards the LEP Preinjector Controls. The main impact of this phase is in the architectural change, as both the front-end minicomputers and the CAMAC embedded microprocessors are replaced by microprocessor based VME crates called Device Stub Controllers (DSC). This paper discusses the different steps planned for this first phase, i.e: (1) implementing the basic set of CERN Accelerator common facilities for DSCs (error handling, system surveillance, remote boot and network access); (2) porting the equipment access software layer; (3) applying the Real-time tasks to the LynxOS operating system and I/O architecture, conforming to the real-time constraints for control and acquisition; (4) defining the number and contents of the different DSC needed, according to geographical and cpu-load constraints; (5) providing the general services outside the DSC crates (file servers, data-base services); (6) emulating the current Console programs onto the new workstations. (author)

  7. Network-Based Models in Molecular Biology

    Science.gov (United States)

    Beyer, Andreas

    Biological systems are characterized by a large number of diverse interactions. Interaction maps have been used to abstract those interactions at all biological scales ranging from food webs at the ecosystem level down to protein interaction networks at the molecular scale.

  8. A high-throughput, restriction-free cloning and screening strategy based on ccdB-gene replacement.

    Science.gov (United States)

    Lund, Bjarte Aarmo; Leiros, Hanna-Kirsti Schrøder; Bjerga, Gro Elin Kjæreng

    2014-03-10

    In high-throughput demanding fields, such as biotechnology and structural biology, molecular cloning is an essential tool in obtaining high yields of recombinant protein. Here, we address recently developed restriction-free methods in cloning, and present a more cost-efficient protocol that has been optimized to improve both cloning and clone screening. In our case study, three homologous β-lactamase genes were successfully cloned using these restriction-free protocols. To clone the genes, we chose a gene replacement strategy, where the recombinant genes contained overhangs that targeted a region of the expression vector including a cytotoxin-encoding ccdB-gene. We provide further evidence that gene replacement can be applied with high-throughput cloning protocols. Targeting a replacement of the ccdB-gene was found to be very successful for counterselection using these protocols. This eliminated the need for treatment with the restriction enzyme DpnI that has so far been the preferred clone selection approach. We thus present an optimized cloning protocol using a restriction-free ccdB-gene replacement strategy, which allows for parallel cloning at a high-throughput level.

  9. A DNA sequence obtained by replacement of the dopamine RNA aptamer bases is not an aptamer.

    Science.gov (United States)

    Álvarez-Martos, Isabel; Ferapontova, Elena E

    2017-08-05

    A unique specificity of the aptamer-ligand biorecognition and binding facilitates bioanalysis and biosensor development, contributing to discrimination of structurally related molecules, such as dopamine and other catecholamine neurotransmitters. The aptamer sequence capable of specific binding of dopamine is a 57 nucleotides long RNA sequence reported in 1997 (Biochemistry, 1997, 36, 9726). Later, it was suggested that the DNA homologue of the RNA aptamer retains the specificity of dopamine binding (Biochem. Biophys. Res. Commun., 2009, 388, 732). Here, we show that the DNA sequence obtained by the replacement of the RNA aptamer bases for their DNA analogues is not able of specific biorecognition of dopamine, in contrast to the original RNA aptamer sequence. This DNA sequence binds dopamine and structurally related catecholamine neurotransmitters non-specifically, as any DNA sequence, and, thus, is not an aptamer and cannot be used neither for in vivo nor in situ analysis of dopamine in the presence of structurally related neurotransmitters. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Optimal replacement time estimation for machines and equipment based on cost function

    Directory of Open Access Journals (Sweden)

    J. Šebo

    2013-01-01

    Full Text Available The article deals with a multidisciplinary issue of estimating the optimal replacement time for the machines. Considered categories of machines, for which the optimization method is usable, are of the metallurgical and engineering production. Different models of cost function are considered (both with one and two variables. Parameters of the models were calculated through the least squares method. Models testing show that all are good enough, so for estimation of optimal replacement time is sufficient to use simpler models. In addition to the testing of models we developed the method (tested on selected simple model which enable us in actual real time (with limited data set to indicate the optimal replacement time. The indicated time moment is close enough to the optimal replacement time t*.

  11. [Department of the molecular bases of semiotics].

    Science.gov (United States)

    Ternovyĭ, K S

    1995-01-01

    Department of molecular basis of semiotics was organized in 1986. The main task of the department was to work out new approaches in estimation of the state of immune and blood system at the tissue, cell and molecular levels, using biochemical, biophysical and molecular biology techniques. There are several main directions of scientific investigations at the department. Most informational methods were collected in "immunological portrait" for differential diagnostic and complex investigation of the immune system of autoimmune patients. This group of techniques was used to study changes in the immune system of Kievites after the Chernobyl disaster. A decrease of complement and thymic serum activity was detected. Antibodies against nuclear components appeared in 20% of donors. And a higher of circulating immune complex of low molecular weight was observed. Low level of thymic serum activity in blood of autoimmune patients with rheumatoid arthritis, lupus erythematosus, diabetes, herpes and other depends on the appearance of zinc-independent timuline inhibitor less then 2000 D. Another kind of thymic hormone inhibitors was detected in thymectomized adult mice. Its effect disappears when zinc added in blood rather due to competition for lymphocyte surface receptors timuline and its inactive analogue than other mechanism. Therapeutic effect of UV irradiation of patients' blood was shown to be closely connected with the changes in thymic serum activity in respect to stabilization of thymic hormone/inhibitor ratio. The immunochemical techniques were used to detect and investigate tumor-associated chromatin antigens in human and animal tumor cells. Antigens not found in normal tissues were detected when using rabbit antibodies against chromatin of rat hepatocarcinoma and human colon and carcinoma.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Optimal replacement time estimation for machines and equipment based on cost function

    OpenAIRE

    J. Šebo; J. Buša; P. Demeč; J. Svetlík

    2013-01-01

    The article deals with a multidisciplinary issue of estimating the optimal replacement time for the machines. Considered categories of machines, for which the optimization method is usable, are of the metallurgical and engineering production. Different models of cost function are considered (both with one and two variables). Parameters of the models were calculated through the least squares method. Models testing show that all are good enough, so for estimation of optimal replacement time is ...

  13. Time-driven activity based costing of total knee replacement surgery at a London teaching hospital.

    Science.gov (United States)

    Chen, Alvin; Sabharwal, Sanjeeve; Akhtar, Kashif; Makaram, Navnit; Gupte, Chinmay M

    2015-12-01

    The aim of this study was to conduct a time-driven activity based costing (TDABC) analysis of the clinical pathway for total knee replacement (TKR) and to determine where the major cost drivers lay. The in-patient pathway was prospectively mapped utilising a TDABC model, following 20 TKRs. The mean age for these patients was 73.4 years. All patients were ASA grade I or II and their mean BMI was 30.4. The 14 varus knees had a mean deformity of 5.32° and the six valgus knee had a mean deformity of 10.83°. Timings were prospectively collected as each patient was followed through the TKR pathway. Pre-operative costs including pre-assessment and joint school were £ 163. Total staff costs for admission and the operating theatre were £ 658. Consumables cost for the operating theatre were £ 1862. The average length of stay was 5.25 days at a total cost of £ 910. Trust overheads contributed £ 1651. The overall institutional cost of a 'noncomplex' TKR in patients without substantial medical co-morbidities was estimated to be £ 5422, representing a profit of £ 1065 based on a best practice tariff of £ 6487. The major cost drivers in the TKR pathway were determined to be theatre consumables, corporate overheads, overall ward cost and operating theatre staffing costs. Appropriate discounting of implant costs, reduction in length of stay by adopting an enhanced recovery programme and control of corporate overheads through the use of elective orthopaedic treatment centres are proposed approaches for reducing the overall cost of treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Determinants of molecular marker based classification of rice (Oryza ...

    African Journals Online (AJOL)

    mr devi singh

    2015-01-07

    Jan 7, 2015 ... The present communication is aimed to find out determinants of molecular marker based classification of rice (Oryza sativa L) germplasm using the available data from an experiment conducted for development of molecular fingerprints of diverse varieties of Basmati and non Basmati rice adapted to.

  15. A New Variable Selection Method Based on Mutual Information Maximization by Replacing Collinear Variables for Nonlinear Quantitative Structure-Property Relationship Models

    International Nuclear Information System (INIS)

    Ghasemi, Jahan B.; Zolfonoun, Ehsan

    2012-01-01

    Selection of the most informative molecular descriptors from the original data set is a key step for development of quantitative structure activity/property relationship models. Recently, mutual information (MI) has gained increasing attention in feature selection problems. This paper presents an effective mutual information-based feature selection approach, named mutual information maximization by replacing collinear variables (MIMRCV), for nonlinear quantitative structure-property relationship models. The proposed variable selection method was applied to three different QSPR datasets, soil degradation half-life of 47 organophosphorus pesticides, GC-MS retention times of 85 volatile organic compounds, and water-to-micellar cetyltrimethylammonium bromide partition coefficients of 62 organic compounds.The obtained results revealed that using MIMRCV as feature selection method improves the predictive quality of the developed models compared to conventional MI based variable selection algorithms

  16. A New Variable Selection Method Based on Mutual Information Maximization by Replacing Collinear Variables for Nonlinear Quantitative Structure-Property Relationship Models

    Energy Technology Data Exchange (ETDEWEB)

    Ghasemi, Jahan B.; Zolfonoun, Ehsan [Toosi University of Technology, Tehran (Korea, Republic of)

    2012-05-15

    Selection of the most informative molecular descriptors from the original data set is a key step for development of quantitative structure activity/property relationship models. Recently, mutual information (MI) has gained increasing attention in feature selection problems. This paper presents an effective mutual information-based feature selection approach, named mutual information maximization by replacing collinear variables (MIMRCV), for nonlinear quantitative structure-property relationship models. The proposed variable selection method was applied to three different QSPR datasets, soil degradation half-life of 47 organophosphorus pesticides, GC-MS retention times of 85 volatile organic compounds, and water-to-micellar cetyltrimethylammonium bromide partition coefficients of 62 organic compounds.The obtained results revealed that using MIMRCV as feature selection method improves the predictive quality of the developed models compared to conventional MI based variable selection algorithms.

  17. Hip Replacement

    Science.gov (United States)

    Hip replacement is surgery for people with severe hip damage. The most common cause of damage is osteoarthritis. Osteoarthritis ... pain medicines, and exercise haven't helped, hip replacement surgery might be an option for you. During ...

  18. 3D printing based on cardiac CT assists anatomic visualization prior to transcatheter aortic valve replacement.

    Science.gov (United States)

    Ripley, Beth; Kelil, Tatiana; Cheezum, Michael K; Goncalves, Alexandra; Di Carli, Marcelo F; Rybicki, Frank J; Steigner, Mike; Mitsouras, Dimitrios; Blankstein, Ron

    2016-01-01

    3D printing is a promising technique that may have applications in medicine, and there is expanding interest in the use of patient-specific 3D models to guide surgical interventions. To determine the feasibility of using cardiac CT to print individual models of the aortic root complex for transcatheter aortic valve replacement (TAVR) planning as well as to determine the ability to predict paravalvular aortic regurgitation (PAR). This retrospective study included 16 patients (9 with PAR identified on blinded interpretation of post-procedure trans-thoracic echocardiography and 7 age, sex, and valve size-matched controls with no PAR). 3D printed models of the aortic root were created from pre-TAVR cardiac computed tomography data. These models were fitted with printed valves and predictions regarding post-implant PAR were made using a light transmission test. Aortic root 3D models were highly accurate, with excellent agreement between annulus measurements made on 3D models and those made on corresponding 2D data (mean difference of -0.34 mm, 95% limits of agreement: ± 1.3 mm). The 3D printed valve models were within 0.1 mm of their designed dimensions. Examination of the fit of valves within patient-specific aortic root models correctly predicted PAR in 6 of 9 patients (6 true positive, 3 false negative) and absence of PAR in 5 of 7 patients (5 true negative, 2 false positive). Pre-TAVR 3D-printing based on cardiac CT provides a unique patient-specific method to assess the physical interplay of the aortic root and implanted valves. With additional optimization, 3D models may complement traditional techniques used for predicting which patients are more likely to develop PAR. Copyright © 2016 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

  19. Molecular recognition in poly(epsilon-caprolactone)-based thermoplastic elastomers

    NARCIS (Netherlands)

    Wisse, Eva; Spiering, A. J. H.; van Leeuwen, Ellen N. M.; Renken, Raymond A. E.; Dankers, Patricia Y. W.; Brouwer, Linda A.; van Luyn, Marja J. A.; Harmsen, Martin C.; Sommerdijk, Nico A. J. M.; Meijer, E. W.

    2006-01-01

    The molecular recognition properties of the hydrogen bonding segments in biodegradable thermoplastic elastomers were explored, aiming at the further functionalization of these potentially interesting biomaterials. A poly(epsilon-caprolactone)-based poly(urea) 2 was synthesized and characterized in

  20. Viable Rayon composite replacement: Micro-cracking in polyacrylonitrile-based carbon-phenolic composites

    Science.gov (United States)

    Mills, Vernon Pete

    Rayon/SC-1008 fiber-based composite materials have been used successfully to line the inner surface of ablative nozzles. But Rayon is no longer produced locally in the United States, primarily due to environmental considerations. The material is available from suppliers located overseas but, for military purposes, there is a pressing need to eliminate foreign dependence. The primary objective of this dissertation is to find a suitable replacement for the Rayon composites currently used in ablative nozzle applications. Other researchers tried to do this by using a composite system consisting of PAN fiber cured with a phenolic resin (91LD). But micro-cracking occurred in the cured resin due to moisture loss over time. The progressive moisture loss, and subsequent shrinkage of the material, induced residual stresses that ultimately resulted in delamination as the material desiccated. PAN fiber was selected to reinforce the composite system in this dissertation because it mimics the structural behavior of Rayon fiber and is readily available from manufacturers located in the United States. The main challenge was to find a matrix material that could cure the PAN fibers into a composite system that would perform equal to, or better than, its Rayon counterpart. Three different resins (SC-1008, PETI-5 and CelazoleRTM) were selected for the matrix based on recommendations found in the literature. Although the majority of applications associated with Rayon rely on the use of pre-impregnated materials, comparisons were made herein using wet hand lay-ups, simply because the PAN composites targeted for study were not readily available in a pre-impregnated form. A Rayon composite panel was fabricated to serve as a baseline. The performance of other material candidates was compared to that of the baseline using: a micro-crack study conducted with photomicrography, thermal gravimetric analysis (TGA), residual volatile (RV) loss measurements, and a thermal mechanical analysis (TMA

  1. A Petri net-based modelling of replacement strategies under technological obsolescence

    Energy Technology Data Exchange (ETDEWEB)

    Clavareau, Julien [Universite Libre de Bruxelles (U.L.B.), Service de Metrologie Nucleaire, Av. F.D. Roosevelt, 50 (CP165/84), Bruxelles B-1050 (Belgium)], E-mail: jclavare@ulb.ac.be; Labeau, Pierre-Etienne [Universite Libre de Bruxelles (U.L.B.), Service de Metrologie Nucleaire, Av. F.D. Roosevelt, 50 (CP165/84), Bruxelles B-1050 (Belgium)

    2009-02-15

    The technological obsolescence of a unit is characterised by the existence of challenger units displaying identical functionalities, but with higher performances. Though this issue is commonly encountered in practice, it has received little consideration in the literature. Previous exploratory works have treated the problem of replacing old-technology items by new ones, for identical components facing a unique new generation of items. This paper aims to define, in a realistic way, possible replacement policies when several types of challenger units are available and when the performances of these newly available units improve with time. Since no fully generic model can exist in maintenance optimisation, a modular modelling of the problem, allowing easy adaptations to features corresponding to specific applications is highly desirable. This work therefore proposes a modular Petri net model for this problem, underlying a Monte Carlo (MC) estimation of the costs incurred by the different possible replacement strategies under consideration.

  2. Controlling charge current through a DNA based molecular transistor

    Energy Technology Data Exchange (ETDEWEB)

    Behnia, S., E-mail: s.behnia@sci.uut.ac.ir; Fathizadeh, S.; Ziaei, J.

    2017-01-05

    Molecular electronics is complementary to silicon-based electronics and may induce electronic functions which are difficult to obtain with conventional technology. We have considered a DNA based molecular transistor and study its transport properties. The appropriate DNA sequence as a central chain in molecular transistor and the functional interval for applied voltages is obtained. I–V characteristic diagram shows the rectifier behavior as well as the negative differential resistance phenomenon of DNA transistor. We have observed the nearly periodic behavior in the current flowing through DNA. It is reported that there is a critical gate voltage for each applied bias which above it, the electrical current is always positive. - Highlights: • Modeling a DNA based molecular transistor and studying its transport properties. • Choosing the appropriate DNA sequence using the quantum chaos tools. • Choosing the functional interval for voltages via the inverse participation ratio tool. • Detecting the rectifier and negative differential resistance behavior of DNA.

  3. Bibliographic data base on atomic and molecular data

    International Nuclear Information System (INIS)

    Itikawa, Yukikazu.

    1983-03-01

    A comparative study is made on three bibliographic data bases: INSPEC, ORNL - AMPIC, GAPHYOR. An on - line retrieval is carried out for searching a number of specific atomic and molecular data. Characteristics of each data base are clarified and suggestions are given for use of those data bases. (author)

  4. Hormone replacement therapy, oral contraceptive use, and distal large bowel cancer: a population-based case-control study.

    Science.gov (United States)

    Long, Millie D; Martin, Christopher F; Galanko, Joseph A; Sandler, Robert S

    2010-08-01

    Lower incidence rates of distal large bowel cancer in women when compared with men support the protective role of female hormones. We aimed to determine the associations between hormone replacement therapy, oral contraceptive use, and distal large bowel cancer. We conducted a population-based case-control study of incident distal large bowel cancer in North Carolina between 2001 and 2006. Data on hormone replacement therapy, oral contraceptive use, demographics, and risk factors were obtained through in-person interviews. Odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between oral contraceptive use, hormone replacement therapy, and distal large bowel cancer were estimated through unconditional logistic regression models overall, by duration of use, and within strata of race. There were a total of 443 women with distal large bowel cancer and 405 controls. Ever use of hormone replacement therapy was strongly associated with a reduced risk of distal large bowel cancer (OR 0.52, 95% CI 0.38-0.72). Further reduction of distal large bowel cancer risk occurred with increased duration of use (or=15 years (OR 0.34, 95% CI 0.20-0.58)). Ever use of oral contraceptives was not associated with reduced incidence of distal large bowel cancer (OR 0.95, 95% CI 0.67-1.34) nor was duration of use. There were no differences by race. Hormone replacement therapy is associated with a lower risk of distal large bowel cancer. This risk is further reduced with increased duration of use. Hormone replacement therapy may be partially responsible for the reduced incidence of distal large bowel cancer in women compared with men.

  5. Optimal separable bases and molecular collisions

    International Nuclear Information System (INIS)

    Poirier, L.W.

    1997-12-01

    A new methodology is proposed for the efficient determination of Green's functions and eigenstates for quantum systems of two or more dimensions. For a given Hamiltonian, the best possible separable approximation is obtained from the set of all Hilbert space operators. It is shown that this determination itself, as well as the solution of the resultant approximation, are problems of reduced dimensionality for most systems of physical interest. Moreover, the approximate eigenstates constitute the optimal separable basis, in the sense of self-consistent field theory. These distorted waves give rise to a Born series with optimized convergence properties. Analytical results are presented for an application of the method to the two-dimensional shifted harmonic oscillator system. The primary interest however, is quantum reactive scattering in molecular systems. For numerical calculations, the use of distorted waves corresponds to numerical preconditioning. The new methodology therefore gives rise to an optimized preconditioning scheme for the efficient calculation of reactive and inelastic scattering amplitudes, especially at intermediate energies. This scheme is particularly suited to discrete variable representations (DVR's) and iterative sparse matrix methods commonly employed in such calculations. State to state and cumulative reactive scattering results obtained via the optimized preconditioner are presented for the two-dimensional collinear H + H 2 → H 2 + H system. Computational time and memory requirements for this system are drastically reduced in comparison with other methods, and results are obtained for previously prohibitive energy regimes

  6. Highly Cross-Linked Polyethylene in Total Hip and Knee Replacement: Spatial Distribution of Molecular Orientation and Shape Recovery Behavior

    Directory of Open Access Journals (Sweden)

    Yasuhito Takahashi

    2014-01-01

    Full Text Available The present study investigated effects of processing procedures on morphology of highly cross-linked and re-melted UHMWPE (XLPE in total hip and knee arthroplasty (THA, TKA. The shape recovery behavior was also monitored via uniaxial compression test at room temperature after non-destructive characterizations of the in-depth microstructure by confocal/polarized Raman spectroscopy. The goal of this study was to relate the manufacturing-induced morphology to the in vivo micromechanical performance, and ultimately to explore an optimal structure in each alternative joint bearing. It was clearly confirmed that the investigated XLPE hip and knee implants, which were produced from different orthopaedic grade resins (GUR 1050 and GUR 1020, consisted of two structural regions in the as-received states: the near-surface transitional anisotropic layer (≈100 μm thickness and the bulk isotropic structural region. These XLPEs exhibited a different crystalline anisotropy and molecular texture within the near-surface layers. In addition, the knee insert showed a slightly higher efficiency of shape recovery against the applied strain over the hip liner owing to a markedly higher percentage of the bulk amorphous phase with intermolecular cross-linking. The quantitative data presented in this study might contribute to construct manufacturing strategies for further rationalized structures as alternative bearings in THA and TKA.

  7. From Electrochemical Biosensors to Biomimetic Sensors Based on Molecularly Imprinted Polymers in Environmental Determination of Heavy Metals

    Directory of Open Access Journals (Sweden)

    Cosimino Malitesta

    2017-07-01

    Full Text Available Recent work relevant to heavy metal determination by inhibition-enzyme electrochemical biosensors and by selected biomimetic sensors based on molecularly imprinted polymers has been reviewed. General features and peculiar aspects have been evidenced. The replace of biological component by artificial receptors promises higher selectivity and stability, while biosensors keep their capability of producing an integrated response directly related to biological toxicity of the samples.

  8. The 1.1 Å resolution structure of a periplasmic phosphate-binding protein from Stenotrophomonas maltophilia: a crystallization contaminant identified by molecular replacement using the entire Protein Data Bank.

    Science.gov (United States)

    Keegan, Ronan; Waterman, David G; Hopper, David J; Coates, Leighton; Taylor, Graham; Guo, Jingxu; Coker, Alun R; Erskine, Peter T; Wood, Steve P; Cooper, Jonathan B

    2016-08-01

    During efforts to crystallize the enzyme 2,4-dihydroxyacetophenone dioxygenase (DAD) from Alcaligenes sp. 4HAP, a small number of strongly diffracting protein crystals were obtained after two years of crystal growth in one condition. The crystals diffracted synchrotron radiation to almost 1.0 Å resolution and were, until recently, assumed to be formed by the DAD protein. However, when another crystal form of this enzyme was eventually solved at lower resolution, molecular replacement using this new structure as the search model did not give a convincing solution with the original atomic resolution data set. Hence, it was considered that these crystals might have arisen from a protein impurity, although molecular replacement using the structures of common crystallization contaminants as search models again failed. A script to perform molecular replacement using MOLREP in which the first chain of every structure in the PDB was used as a search model was run on a multi-core cluster. This identified a number of prokaryotic phosphate-binding proteins as scoring highly in the MOLREP peak lists. Calculation of an electron-density map at 1.1 Å resolution based on the solution obtained with PDB entry 2q9t allowed most of the amino acids to be identified visually and built into the model. A BLAST search then indicated that the molecule was most probably a phosphate-binding protein from Stenotrophomonas maltophilia (UniProt ID B4SL31; gene ID Smal_2208), and fitting of the corresponding sequence to the atomic resolution map fully corroborated this. Proteins in this family have been linked to the virulence of antibiotic-resistant strains of pathogenic bacteria and with biofilm formation. The structure of the S. maltophilia protein has been refined to an R factor of 10.15% and an Rfree of 12.46% at 1.1 Å resolution. The molecule adopts the type II periplasmic binding protein (PBP) fold with a number of extensively elaborated loop regions. A fully dehydrated phosphate

  9. Economic assessment of traditional surgical intervention versus use of a new innovative radiofrequency based surgical system in device replacements

    Science.gov (United States)

    Kammler, Juergen; Nahler, Alexander; Neeser, Kurt; Lichtenauer, Michael; Edlinger, Christoph; Kellermair, Joerg; Kiblboeck, Daniel; Lambert, Thomas; Auer, Johannes; Steinwender, Clemens

    2018-01-01

    Introduction Intra-operative complications like mechanical damages to the leads, infections and hematomas during generator replacements of implantable pacemakers and defibrillators contribute to additional costs for hospitals. The aim of this study was to evaluate operation room use, costs and budget impact of generator replacements using either a traditional surgical intervention (TSI) with scissors, scalpel and electrocautery vs. a new radiofrequency energy based surgical system, called PEAK PlasmaBladeTM (PPB). Materials and methods We conducted a retrospective analysis of a population including 508 patients with TSI and 254 patients with PPB who underwent generator replacement at the Kepler University Hospital in Linz or the St. Josef Hospital in Braunau, Austria. The economic analysis included costs of resources used for intra-operative complications (lead damages) and of procedure time for TSI vs. PPB. Results Proportion of males, mean age and type of generator replaced were similar between the two groups. Lead damages occurred significantly more frequent with TSI than with PPB (5.3% and 0.4%; p< 0.001) and the procedure time was significantly longer with TSI than with PPB (47.9±24.9 and 34.1±18.1 minutes; p<0.001). Shorter procedure time and a lower rate of lead damages with PPB resulted in per patient cost savings of €81. Based on estimated 2,700 patients annually undergoing generator replacement in Austria, the use of PPB may translate into cost savings of €219,600 and 621 saved operating facility hours. Conclusion PPB has the potential to minimize the risk of lead damage with more efficient utilization of the operating room. Along with cost savings and improved quality of care, hospitals may use the saved operating room hours to increase the number of daily surgeries. PMID:29509774

  10. Economic assessment of traditional surgical intervention versus use of a new innovative radiofrequency based surgical system in device replacements.

    Science.gov (United States)

    Kypta, Alexander; Blessberger, Hermann; Kammler, Juergen; Nahler, Alexander; Neeser, Kurt; Lichtenauer, Michael; Edlinger, Christoph; Kellermair, Joerg; Kiblboeck, Daniel; Lambert, Thomas; Auer, Johannes; Steinwender, Clemens

    2018-01-01

    Intra-operative complications like mechanical damages to the leads, infections and hematomas during generator replacements of implantable pacemakers and defibrillators contribute to additional costs for hospitals. The aim of this study was to evaluate operation room use, costs and budget impact of generator replacements using either a traditional surgical intervention (TSI) with scissors, scalpel and electrocautery vs. a new radiofrequency energy based surgical system, called PEAK PlasmaBladeTM (PPB). We conducted a retrospective analysis of a population including 508 patients with TSI and 254 patients with PPB who underwent generator replacement at the Kepler University Hospital in Linz or the St. Josef Hospital in Braunau, Austria. The economic analysis included costs of resources used for intra-operative complications (lead damages) and of procedure time for TSI vs. PPB. Proportion of males, mean age and type of generator replaced were similar between the two groups. Lead damages occurred significantly more frequent with TSI than with PPB (5.3% and 0.4%; pTSI than with PPB (47.9±24.9 and 34.1±18.1 minutes; p<0.001). Shorter procedure time and a lower rate of lead damages with PPB resulted in per patient cost savings of €81. Based on estimated 2,700 patients annually undergoing generator replacement in Austria, the use of PPB may translate into cost savings of €219,600 and 621 saved operating facility hours. PPB has the potential to minimize the risk of lead damage with more efficient utilization of the operating room. Along with cost savings and improved quality of care, hospitals may use the saved operating room hours to increase the number of daily surgeries.

  11. A delay time model for a mission-based system subject to periodic and random inspection and postponed replacement

    International Nuclear Information System (INIS)

    Yang, Li; Ma, Xiaobing; Zhai, Qingqing; Zhao, Yu

    2016-01-01

    We propose an inspection and replacement policy for a single component system that successively executes missions with random durations. The failure process of the system can be divided into two states, namely, normal and defective, following the delay time concept. Inspections are carried out periodically and immediately after the completion of each mission (random inspections). The failed state is always identified immediately, whereas the defective state can only be revealed by an inspection. If the system fails or is defective at a periodic inspection, then replacement is immediate. If, however, the system is defective at a random inspection, then replacement will be postponed if the time to the subsequent periodic inspection is shorter than a pre-determined threshold, and immediate otherwise. We derive the long run expected cost per unit time and then investigate the optimal periodic inspection interval and postponement threshold. A numerical example is presented to demonstrate the applicability of the proposed maintenance policy. - Highlights: • A delay time model of inspection is introduced for mission-based systems. • Periodic and random inspections are performed to check the state. • Replacement of the defective system at a random inspection can be postponed.

  12. A method of meta-mechanism combination and replacement based on motion study

    Directory of Open Access Journals (Sweden)

    Yadong Fang

    2015-01-01

    Full Text Available Lacking the effective methods to reduce labor and cost, many small- and medium-sized assembly companies are facing with the problem of high cost for a long time. In order to reduce costs of manual operations, the method of meta-mechanism combination and replacement is studied. In this paper, we mainly discuss assembling motion analysis, workpieces position information acquisition, motion library construction, assembling motion analysis by Maynard’s operation sequence technique, meta-mechanism database establishment, and match of motion and mechanism. At the same time, the principle, process, and system realization framework of mechanism replacement are introduced. Lastly, problems for low-cost automation of the production line are basically resolved by operator motion analysis and meta-mechanism combination and match.

  13. An evaluation of replacement rates for posterior resin-based composite and amalgam restorations in U.S. Navy and marine corps recruits.

    Science.gov (United States)

    Simecek, John W; Diefenderfer, Kim E; Cohen, Mark E

    2009-02-01

    Restoration replacement is a clinical concern that has not been studied among military personnel. The authors determined the prevalence of placement of posterior amalgam and resin-based composite restorations and the incidence of replacement among U.S. Navy and Marine Corps personnel. The authors analyzed dental records from 2,780 personnel to determine the relative risk of replacement for initially sound restorations during subjects' first years of military service. At the initial examination, 964 (15.2 percent) of amalgam restorations and 199 (17.4 percent) of resin-based composite restorations required re-treatment. Of those judged clinically acceptable, 14.2 percent of amalgam and 16.7 percent of resin-based composite restorations required replacement during the observation period. The authors found significant increases in replacement rates for resin-based composite restorations compared with amalgam restorations for replacement due to all causes (adjusted hazard ratio, 1.28; P composite restorations in place at the initial examination will require replacement than will amalgam restorations. Multi-surface restorations had higher rates of replacement than did one-surface restorations, and subjects at high caries risk experienced significantly higher replacement rates than did those at low caries risk. The number of surfaces restored and subjects' caries risk status may influence the longevity of resin-based composite and amalgam restorations.

  14. Unidirectional Light-Driven Molecular Motors Based on Overcrowded Alkenes

    NARCIS (Netherlands)

    Cnossen, Arjen; Browne, Wesley R.; Feringa, Ben L.; Credi, Alberto; Silvi, Serena; Venturi, Margherita

    2014-01-01

    Over the last two decades, interest in nanotechnology has led to the design and synthesis of a toolbox of nanoscale versions of macroscopic devices and components. In molecular nanotechnology, linear motors based on rotaxanes and rotary motors based on overcrowded alkenes are particularly promising

  15. Progress in molecular-based management of differentiated thyroid cancer

    Science.gov (United States)

    Xing, Mingzhao; Haugen, Bryan R; Schlumberger, Martin

    2014-01-01

    Substantial developments have occurred in the past 5–10 years in clinical translational research of thyroid cancer. Diagnostic molecular markers, such as RET-PTC, RAS, and BRAFV600E mutations; galectin 3; and a new gene expression classifier, are outstanding examples that have improved diagnosis of thyroid nodules. BRAF mutation is a prognostic genetic marker that has improved risk stratification and hence tailored management of patients with thyroid cancer, including those with conventionally low risks. Novel molecular-targeted treatments hold great promise for radioiodine-refractory and surgically inoperable thyroid cancers as shown in clinical trials; such treatments are likely to become a component of the standard treatment regimen for patients with thyroid cancer in the near future. These novel molecular-based management strategies for thyroid nodules and thyroid cancer are the most exciting developments in this unprecedented era of molecular thyroid-cancer medicine. PMID:23668556

  16. Road construction replaceable materials. An alternative to oil-based materials

    International Nuclear Information System (INIS)

    Deneuvillers, C.; Chappat, M.

    2008-01-01

    For some time the world has been subjected enormous upheavals with regard to energy resources: on one hand there is the steep rise in the price of oil and the other energy sources whose price depends on it; on the other hand, the prospects are that during the next 25 to 30 years oil resources will become increasingly scarce, which raises the problem of its replacement. This situation obviously raises the vital question of the present and future energy needs of each country, and, consequently, what type of energy. These are not only political issues but also issues for society. How could the roads sector help to find at least partial solutions? This paper will describe a policy adopted by a private sector construction company which is determined to apply the criteria of sustainable development and green chemistry in its products. Bitumen is a derivative of oil, can it be replaced? Most of the chemical products used in roads are petrochemical in nature, can they be replaced? Turning towards vegetable resources provides one way of reducing energy dependency. The paper demonstrates how this could be done, and at what price and with what precautions. This topic inevitably involves a discussion of the criteria of life-cycle analysis and an examination of how they can be applied in a clear manner. This response from industry has already provided some excellent results, which are described in this paper. It also attempts to show how vegetable resources may provide an opportunity for both developing and developed countries. The first could produce a new energy resource and increase their standard of living. The second could be a partial solution to their energy resources problems. Roads, which provide a universal link between different peoples, may still provide a future and hope. (authors)

  17. CEO- CNE relationships: building an evidence-base of chief nursing executive replacement costs.

    Science.gov (United States)

    Sredl, Darlene; Peng, Niang-Huei

    2010-06-03

    Explore professional relationships between Chief Nurse Executives (CNEs) and Chief Executive Officers (CEOs); CNE ethnic diversity; and CNE replacement costs. Theoretical frameworks - Marilyn Ray's Theory of Bureaucratic Caring, and Turkel's Theory of Relational Complexity espousing economic as well as caring variables. Exploratory mixed-method descriptive design using CNE mailed survey. CNE- cited opportunities for maintaining a positive relationship with the CEO: respect for CEO; goal- sharing (r=.782, p<0.01); having a strong relationship (r= .718, p<0.01); co-problem-solving (r=.437, p<0.01); having an interesting job (r=.406, p<0.01); having similar interests with CEO (r= .346, p<0.01); CEO and CNE maintaining specific roles (r= .261, p<0.05); satisfaction with CNE income (r=.251, p<0.05); willingness to improve relationship with CEO (r=.254, p<0.05). CNE positions demonstrated an ethnic diversity factor of 0.03%. CNE replacement costs to healthcare facilities were over 1.5 million dollars. CNE/CEO relationships have identified cohesive factors that may contribute to CNE longevity in position; an ethically diverse CNE deficit exists; and, CNE turnover and vacancy rates impact an organization's financial health and quality of care.

  18. Proposal for a strategic planning for the replacement of products in stores based on sales forecast

    Directory of Open Access Journals (Sweden)

    Cassius Tadeu Scarpin

    2011-08-01

    Full Text Available This paper presents a proposal for strategic planning for the replacement of products in stores of a supermarket network. A quantitative method for forecasting time series is used for this, the Artificial Radial Basis Neural Networks (RBFs, and also a qualitative method to interpret the forecasting results and establish limits for each product stock for each store in the network. The purpose with this strategic planning is to reduce the levels of out-of-stock products (lack of products on the shelves, as well as not to produce overstocking, in addition to increase the level of logistics service to customers. The results were highly satisfactory reducing the Distribution Center (DC to shop out-of-stock levels, in average, from 12% to about 0.7% in hypermarkets and from 15% to about 1.7% in supermarkets, thereby generating numerous competitive advantages for the company. The use of RBFs for forecasting proved to be efficient when used in conjunction with the replacement strategy proposed in this work, making effective the operational processes.

  19. Histological skin morphology enhancement base on molecular hyperspectral imaging technology.

    Science.gov (United States)

    Li, Q; Sun, Z; Wang, Y; Liu, H; Guo, F; Zhu, J

    2014-08-01

    Most traditional skin histological analysis methods are based on the light microscopy images, which can only provide limited information and low contrast results for pathology evaluation. Molecular hyperspectral imaging technology can provide both spatial and spectral information of skin sections, which is a new method for histological skin analysis. The molecular hyperspectral imaging system was developed by coupling an acousto-optic tunable filters adapter to microscopy and the molecular hyperspectral images were analyzed by home-written software with image processing algorithms. Then, the histological structures in skin sections were investigated in several locations to evaluate the potential application of the molecular hyperspectral imaging technique to dermatology. Molecular hyperspectral images of skin sections were obtained. Single-band images, false color images, virtual 3D surface view images, and color-coded spectral clustering results were produced to highlight the skin structures for histological evaluation. Unlike traditional histological analysis with light microscopy, the molecular hyperspectral imaging technology can enhance the visualization of skin structures using their spectral signatures and their gray values. This technology has potential for the diagnosis and histopathologic characterization of different kind of skin cells. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Homoplasy in genome-wide analysis of rare amino acid replacements: the molecular-evolutionary basis for Vavilov's law of homologous series

    Directory of Open Access Journals (Sweden)

    Carmel Liran

    2008-03-01

    Full Text Available Abstract Background Rare genomic changes (RGCs that are thought to comprise derived shared characters of individual clades are becoming an increasingly important class of markers in genome-wide phylogenetic studies. Recently, we proposed a new type of RGCs designated RGC_CAMs (after Conserved Amino acids-Multiple substitutions that were inferred using genome-wide identification of amino acid replacements that were: i located in unambiguously aligned regions of orthologous genes, ii shared by two or more taxa in positions that contain a different, conserved amino acid in a much broader range of taxa, and iii require two or three nucleotide substitutions. When applied to animal phylogeny, the RGC_CAM approach supported the coelomate clade that unites deuterostomes with arthropods as opposed to the ecdysozoan (molting animals clade. However, a non-negligible level of homoplasy was detected. Results We provide a direct estimate of the level of homoplasy caused by parallel changes and reversals among the RGC_CAMs using 462 alignments of orthologous genes from 19 eukaryotic species. It is shown that the impact of parallel changes and reversals on the results of phylogenetic inference using RGC_CAMs cannot explain the observed support for the Coelomata clade. In contrast, the evidence in support of the Ecdysozoa clade, in large part, can be attributed to parallel changes. It is demonstrated that parallel changes are significantly more common in internal branches of different subtrees that are separated from the respective common ancestor by relatively short times than in terminal branches separated by longer time intervals. A similar but much weaker trend was detected for reversals. The observed evolutionary trend of parallel changes is explained in terms of the covarion model of molecular evolution. As the overlap between the covarion sets in orthologous genes from different lineages decreases with time after divergence, the likelihood of parallel

  1. Homoplasy in genome-wide analysis of rare amino acid replacements: the molecular-evolutionary basis for Vavilov's law of homologous series.

    Science.gov (United States)

    Rogozin, Igor B; Thomson, Karen; Csürös, Miklós; Carmel, Liran; Koonin, Eugene V

    2008-03-17

    Rare genomic changes (RGCs) that are thought to comprise derived shared characters of individual clades are becoming an increasingly important class of markers in genome-wide phylogenetic studies. Recently, we proposed a new type of RGCs designated RGC_CAMs (after Conserved Amino acids-Multiple substitutions) that were inferred using genome-wide identification of amino acid replacements that were: i) located in unambiguously aligned regions of orthologous genes, ii) shared by two or more taxa in positions that contain a different, conserved amino acid in a much broader range of taxa, and iii) require two or three nucleotide substitutions. When applied to animal phylogeny, the RGC_CAM approach supported the coelomate clade that unites deuterostomes with arthropods as opposed to the ecdysozoan (molting animals) clade. However, a non-negligible level of homoplasy was detected. We provide a direct estimate of the level of homoplasy caused by parallel changes and reversals among the RGC_CAMs using 462 alignments of orthologous genes from 19 eukaryotic species. It is shown that the impact of parallel changes and reversals on the results of phylogenetic inference using RGC_CAMs cannot explain the observed support for the Coelomata clade. In contrast, the evidence in support of the Ecdysozoa clade, in large part, can be attributed to parallel changes. It is demonstrated that parallel changes are significantly more common in internal branches of different subtrees that are separated from the respective common ancestor by relatively short times than in terminal branches separated by longer time intervals. A similar but much weaker trend was detected for reversals. The observed evolutionary trend of parallel changes is explained in terms of the covarion model of molecular evolution. As the overlap between the covarion sets in orthologous genes from different lineages decreases with time after divergence, the likelihood of parallel changes decreases as well. The level of

  2. Knee joint replacement

    Science.gov (United States)

    Total knee replacement; Knee arthroplasty; Knee replacement - total; Tricompartmental knee replacement; Subvastus knee replacement; Knee replacement - minimally invasive; Knee arthroplasty - minimally ...

  3. Evidence-based decision making: replacement of the single missing tooth.

    Science.gov (United States)

    Fugazzotto, Paul A

    2009-01-01

    Single-tooth replacement may be effected through various methods, including the use of a resin-bonded fixed partial denture, a conventional fixed partial denture, and a single implant-supported crown. Although the introduction of newer therapeutic modalities, surgical and restorative techniques, and restorative materials has significantly expanded available treatment options, a greater demand is now placed on the diagnostic and treatment planning acumen of the clinician. The questions confronting each clinician are when to apply each treatment modality and how to use these therapeutic approaches to their maximum benefit for the patient. This article focuses on the factors that should be considered when making such clinical decisions and offers a framework within which to formulate appropriate treatment algorithms.

  4. Fullerene-based Anchoring Groups for Molecular Electronics

    DEFF Research Database (Denmark)

    Martin, Christian A.; Ding, Dapeng; Sørensen, Jakob Kryger

    2008-01-01

    We present results on a new fullerene-based anchoring group for molecular electronics. Using lithographic mechanically controllable break junctions in vacuum we have determined the conductance and stability of single-molecule junctions of 1,4-bis(fullero[c]pyrrolidin-1-yl)benzene. The compound can...

  5. Molecularly Imprinted Polymer-Carbon Nanotube based Cotinine sensor

    NARCIS (Netherlands)

    Abbas, Yawar; Bomer, Johan G.; Brusse-Keizer, M.G.J.; Movig, K; van der Valk, P.D.L.P.M.; Pieterse, Marcel E.; Segerink, Loes Irene; Olthuis, Wouter; van den Berg, Albert

    2016-01-01

    A cotinine sensor based on the dc resistance of a polymer composite films is presented. The composite film comprises a cotinine selective molecularly imprinted polymer and carbon nanotube particles. This polymer film is deposited over a gold interdigitated electrode array to measure its electrical

  6. Molecular Recognition: Detection of Colorless Compounds Based on Color Change

    Science.gov (United States)

    Khalafi, Lida; Kashani, Samira; Karimi, Javad

    2016-01-01

    A laboratory experiment is described in which students measure the amount of cetirizine in allergy-treatment tablets based on molecular recognition. The basis of recognition is competition of cetirizine with phenolphthalein to form an inclusion complex with ß-cyclodextrin. Phenolphthalein is pinkish under basic condition, whereas it's complex form…

  7. Transforming bases to bytes: Molecular computing with DNA

    Indian Academy of Sciences (India)

    Despite the popular image of silicon-based computers for computation, an embryonic field of mole- cular computation is emerging, where molecules in solution perform computational operations. DNA, which is known to store biological information, is being used as a substrate for molecular computation. In this review, we ...

  8. Replacing penalties

    Directory of Open Access Journals (Sweden)

    Vitaly Stepashin

    2017-01-01

    Full Text Available УДК 343.24The subject. The article deals with the problem of the use of "substitute" penalties.The purpose of the article is to identify criminal and legal criteria for: selecting the replacement punishment; proportionality replacement leave punishment to others (the formalization of replacement; actually increasing the punishment (worsening of legal situation of the convicted.Methodology.The author uses the method of analysis and synthesis, formal legal method.Results. Replacing the punishment more severe as a result of malicious evasion from serving accused designated penalty requires the optimization of the following areas: 1 the selection of a substitute punishment; 2 replacement of proportionality is serving a sentence other (formalization of replacement; 3 ensuring the actual toughening penalties (deterioration of the legal status of the convict. It is important that the first two requirements pro-vide savings of repression in the implementation of the replacement of one form of punishment to others.Replacement of punishment on their own do not have any specifics. However, it is necessary to compare them with the contents of the punishment, which the convict from serving maliciously evaded. First, substitute the punishment should assume a more significant range of restrictions and deprivation of certain rights of the convict. Second, the perfor-mance characteristics of order substitute the punishment should assume guarantee imple-mentation of the new measures.With regard to replacing all forms of punishment are set significant limitations in the application that, in some cases, eliminates the possibility of replacement of the sentence, from serving where there has been willful evasion, a stricter measure of state coercion. It is important in the context of the topic and the possibility of a sentence of imprisonment as a substitute punishment in cases where the original purpose of the strict measures excluded. It is noteworthy that the

  9. Intelligent DNA-based molecular diagnostics using linked genetic markers

    Energy Technology Data Exchange (ETDEWEB)

    Pathak, D.K.; Perlin, M.W.; Hoffman, E.P.

    1994-12-31

    This paper describes a knowledge-based system for molecular diagnostics, and its application to fully automated diagnosis of X-linked genetic disorders. Molecular diagnostic information is used in clinical practice for determining genetic risks, such as carrier determination and prenatal diagnosis. Initially, blood samples are obtained from related individuals, and PCR amplification is performed. Linkage-based molecular diagnosis then entails three data analysis steps. First, for every individual, the alleles (i.e., DNA composition) are determined at specified chromosomal locations. Second, the flow of genetic material among the individuals is established. Third, the probability that a given individual is either a carrier of the disease or affected by the disease is determined. The current practice is to perform each of these three steps manually, which is costly, time consuming, labor-intensive, and error-prone. As such, the knowledge-intensive data analysis and interpretation supersede the actual experimentation effort as the major bottleneck in molecular diagnostics. By examining the human problem solving for the task, we have designed and implemented a prototype knowledge-based system capable of fully automating linkage-based molecular diagnostics in X-linked genetic disorders, including Duchenne Muscular Dystrophy (DMD). Our system uses knowledge-based interpretation of gel electrophoresis images to determine individual DNA marker labels, a constraint satisfaction search for consistent genetic flow among individuals, and a blackboard-style problem solver for risk assessment. We describe the system`s successful diagnosis of DMD carrier and affected individuals from raw clinical data.

  10. Molecular Bases of Enantioselectivity of Haloalkane Dehalogenase DbjA

    Science.gov (United States)

    Sato, Yukari; Natsume, Ryo; Prokop, Zbynek; Brezovsky, Jan; Chaloupkova, Radka; Damborsky, Jiri; Nagata, Yuji; Senda, Toshiya

    Enzymes are widely used for the synthesis of pharmaceuticals, agrochemicals, and food additives because they can catalyze high enantioselective transformations. In order to construct selective enzymes by protein engineering, it is important to understand the molecular basis of enzyme-substrate interactions that contribute to enantioselectivity. The haloalkane dehalogenase DbjA showed high enantioselectivity for two racemic mixtures: α-bromoesters and β-bromoalkanes. Thermodynamic analysis, protein crystallography, and computer simulations indicated that DbjA carries two bases for the enantiodiscrimination of each racemic mixture. This study helps us understand the molecular basis of the enantioselectivity and opens up new possibilities for constructing enantiospecific biocatalysts through protein engineering.

  11. Chemical sensors based on molecularly modified metallic nanoparticles

    International Nuclear Information System (INIS)

    Haick, Hossam

    2007-01-01

    This paper presents a concise, although admittedly non-exhaustive, didactic review of some of the main concepts and approaches related to the use of molecularly modified metal nanoparticles in or as chemical sensors. This paper attempts to pull together different views and terminologies used in sensors based on molecularly modified metal nanoparticles, including those established upon electrochemical, optical, surface Plasmon resonance, piezoelectric and electrical transduction approaches. Finally, this paper discusses briefly the main advantages and disadvantages of each of the presented class of sensors. (review article)

  12. Accelerating convergence of molecular dynamics-based structural relaxation

    DEFF Research Database (Denmark)

    Christensen, Asbjørn

    2005-01-01

    We describe strategies to accelerate the terminal stage of molecular dynamics (MD)based relaxation algorithms, where a large fraction of the computational resources are used. First, we analyze the qualitative and quantitative behavior of the QuickMin family of MD relaxation algorithms and explore...... the influence of spectral properties and dimensionality of the molecular system on the algorithm efficiency. We test two algorithms, the MinMax and Lanczos, for spectral estimation from an MD trajectory, and use this to derive a practical scheme of time step adaptation in MD relaxation algorithms to improve...

  13. Bio-Mimetic Sensors Based on Molecularly Imprinted Membranes

    Directory of Open Access Journals (Sweden)

    Catia Algieri

    2014-07-01

    Full Text Available An important challenge for scientific research is the production of artificial systems able to mimic the recognition mechanisms occurring at the molecular level in living systems. A valid contribution in this direction resulted from the development of molecular imprinting. By means of this technology, selective molecular recognition sites are introduced in a polymer, thus conferring it bio-mimetic properties. The potential applications of these systems include affinity separations, medical diagnostics, drug delivery, catalysis, etc. Recently, bio-sensing systems using molecularly imprinted membranes, a special form of imprinted polymers, have received the attention of scientists in various fields. In these systems imprinted membranes are used as bio-mimetic recognition elements which are integrated with a transducer component. The direct and rapid determination of an interaction between the recognition element and the target analyte (template was an encouraging factor for the development of such systems as alternatives to traditional bio-assay methods. Due to their high stability, sensitivity and specificity, bio-mimetic sensors-based membranes are used for environmental, food, and clinical uses. This review deals with the development of molecularly imprinted polymers and their different preparation methods. Referring to the last decades, the application of these membranes as bio-mimetic sensor devices will be also reported.

  14. Bio-Mimetic Sensors Based on Molecularly Imprinted Membranes

    Science.gov (United States)

    Algieri, Catia; Drioli, Enrico; Guzzo, Laura; Donato, Laura

    2014-01-01

    An important challenge for scientific research is the production of artificial systems able to mimic the recognition mechanisms occurring at the molecular level in living systems. A valid contribution in this direction resulted from the development of molecular imprinting. By means of this technology, selective molecular recognition sites are introduced in a polymer, thus conferring it bio-mimetic properties. The potential applications of these systems include affinity separations, medical diagnostics, drug delivery, catalysis, etc. Recently, bio-sensing systems using molecularly imprinted membranes, a special form of imprinted polymers, have received the attention of scientists in various fields. In these systems imprinted membranes are used as bio-mimetic recognition elements which are integrated with a transducer component. The direct and rapid determination of an interaction between the recognition element and the target analyte (template) was an encouraging factor for the development of such systems as alternatives to traditional bio-assay methods. Due to their high stability, sensitivity and specificity, bio-mimetic sensors-based membranes are used for environmental, food, and clinical uses. This review deals with the development of molecularly imprinted polymers and their different preparation methods. Referring to the last decades, the application of these membranes as bio-mimetic sensor devices will be also reported. PMID:25196110

  15. Initial non-opioid based anesthesia in a parturient having severe aortic stenosis undergoing cesarean section with aortic valve replacement

    Directory of Open Access Journals (Sweden)

    Subrata Podder

    2015-01-01

    Full Text Available Pregnancy in presence of severe aortic stenosis (AS causes worsening of symptoms needing further intervention. In the advanced stages of pregnancy, some patients may even require aortic valve replacement (AVR and cesarean delivery in the same sitting. Opioid based general anesthesia for combined lower segment cesarean section (LSCS with AVR has been described. However, the use of opioid may lead to fetal morbidity and need of respiratory support for the baby. We describe successful anesthetic management for LSCS with AVR in a >33 week gravida with severe AS and congestive heart failure. We avoided opioids till delivery of the baby AVR; the delivered neonate showed a normal APGAR score.

  16. A new class of cuprous bromide cluster-based hybrid materials: direct observation of the stepwise replacement of hydrogen bonds by coordination bonds.

    Science.gov (United States)

    Zhang, Xian-Ming; Hou, Juan-Juan; Guo, Cai-Hong; Li, Chun-Fang

    2015-01-20

    Although a variety of functional metal-organic frameworks (MOFs) have been synthesized, post-modified, and applied in various areas, there is little knowledge about how molecular cluster building units are stepwise evolved into MOFs via intermediates. Coordination bonds are generally stronger than hydrogen bonds, and thus equivalent replacement of X-H···Y hydrogen bonds by X-M-Y coordination bonds can transform hydrogen bond networks into MOFs. In this work, solvothermal in situ reduction reactions of CuBr2 and 1,4-diazoniabicyclo[2,2,2]octane (DABCO) generated a myriad of tunable photoluminescent cuprous body-centered cubic bromide cluster-based networks with the general formula [Cu4+xH4-xBr6(DABCO)4](HCO2)2·S (x = 0, 0.56, 0.81, 1.27, 1.39, 2.56, 2.78, and 4 for compounds 1-8, respectively). All of these compounds crystallize in the cubic space group with the largest volume difference being only 5.2%, but they belong to three remarkably different kinds of crystals. Complex 1 is a molecular crystal and consists of tetrahedral [Cu4Br6(HDABCO)4](2+) clusters with monodentate HDABCO groups that are supported via N-H···Br synthons in the hydrogen bond network. Compound 8 is a [Cu8Br6](2+) cube cluster-based MOF with bridged DABCO ligands. Complexes 2-7 are seemingly impossible Cu/H-substituted solid solutions of 1 and 8. The CuBr framework components in 1-8 are Cu4Br6, Cu4.56Br6, Cu4.81Br6, Cu5.27Br6, Cu5.39Br6, Cu6.56Br6, Cu6.78Br6, and Cu8Br6, respectively. Crystallization kinetics studies revealed that the [Cu4Br6(HDABCO)4](2+) cluster-based hydrogen bond network (1) was initially formed such that N-H···Br hydrogen bonds could be stepwise replaced by N-Cu-Br coordination bonds to form the [Cu8Br6](2+) cube cluster-based MOF (8) via solid solutions. These observations directly reveal the equivalence and transformation between the N-H···Br hydrogen bond and the N-Cu-Br coordination bond and the evolutionary mechanism of a molecular crystal to a MOF via

  17. The ocular benefits of estrogen replacement therapy: a population-based study in postmenopausal Korean women.

    Directory of Open Access Journals (Sweden)

    Kyung-Sun Na

    Full Text Available PURPOSE: To elucidate the prevalence of cataract, glaucoma, pterygia, and diabetic retinopathy among Korean postmenopausal women with or without estrogen replacement therapy (ERT. METHODS: A cross-sectional, nationally representative sample from the 4th Korea National Health and Nutrition Examination Survey (KNHANES IV (2007-2009 was used. Participants were interviewed for the determination of socioeconomic and gynecologic factors. Each woman also underwent an ophthalmologic examination and provided a blood sample for risk factor assessment. RESULTS: Of 3968 postmenopausal women enrolled, 3390 had never received estrogen, and 578 were undergoing estrogen treatment. After adjusting for age, diabetes, hypertension, high cholesterol levels, and high low-density lipoprotein levels, the prevalence of anterior polar cataract, retinal nerve fiber layer (RNFL defect, and flesh pterygium was higher in the non-ERT group (OR, 3.24; 95% CI, 1.12-9.35, OR 1.70; 95% CI, 1.04-2.78, OR 3.725; 95% CI, 1.21-11.45, respectively. Further, the prevalence of atrophic pterygium was lower in the non-ERT group compared to that in the ERT group (OR, 0.21, 95% CI, 0.07-0.63. CONCLUSIONS: These data suggest that ERT has a protective effect against the development of anterior polar cataract, flesh pterygium, and RNFL defect.

  18. [Analysis on replacement of traditional Chinese medicine bear bile with bile acids based on drug properties].

    Science.gov (United States)

    Yuan, Bin; Ren, Ying-Long; Ma, Li; Gu, Hao; Wang, Yun; Qiao, Yan-Jiang

    2014-02-01

    To discuss the rationality of the clinical replacement of traditional Chinese medicine (TCM) bear bile with bile acid constituents, and analyze the difference between these constituents and bear bile in drug properties. Summarizing the drug properties of bear bile by reference to medical literatures for drug properties of TCM bear bile and Science of Traditional Chinese Medicine (China Press of Traditional Chinese Medicine, 2007). Analyzing and summarizing the pharmacological effects of main bile acid constituents according to relevant literatures for studies on pharmacological effects of main bile acid constituents in CNKI database. Predicating the drug properties of these bile acid constituents by using the drug property predication model established by the study group according the pharmacological effects of main bile acid constituents in the paper, and compare the prediction results with the drug properties of bear bile. Bile acid constituents in bear bile were mostly cold in property, bitter in taste, and the combination of their drug properties could reflect the combined drug properties of bear bile. All of these bile acid constituents in bear bile could show part of effects of bear bile. Attention shall be given to regulate the medication scheme in clinical application according to actual conditions.

  19. Improved Laser Manipulation for On-chip Fabricated Microstructures Based on Solution Replacement and Its Application in Single Cell Analysis

    Directory of Open Access Journals (Sweden)

    Tao Yue

    2014-02-01

    Full Text Available In this paper, we present the fabrication and assembly of microstructures inside a microfluidic device based on a photocrosslinkable resin and optical tweezers. We also report a method of solution replacement inside the microfluidic channel in order to improve the manipulation performance and apply the assembled microstructures for single cell cultivation. By the illumination of patterned ultraviolet (UV through a microscope, microstructures of arbitrary shape were fabricated by the photocrosslinkable resin inside a microfluidic channel. Based on the microfluidic channel with both glass and polydimethylsiloxane (PDMS surfaces, immovable and movable microstructures were fabricated and manipulated. The microstructures were fabricated at the desired places and manipulated by the optical tweezers. A rotational microstructure including a microgear and a rotation axis was assembled and rotated in demonstrating this technique. The improved laser manipulation of microstructures was achieved based on the on-chip solution replacement method. The manipulation speed of the microstructures increased when the viscosity of the solvent decreased. The movement efficiency of the fabricated microstructures inside the lower viscosity solvent was evaluated and compared with those microstructures inside the former high viscosity solvent. A novel cell cage was fabricated and the cultivation of a single yeast cell (w303 was demonstrated in the cell cage, inside the microfluidic device.

  20. Effect of partially replacing a barley-based concentrate with flaxseed-based products on the rumen bacterial population of lactating Holstein dairy cows.

    Science.gov (United States)

    Castillo-Lopez, E; Moats, J; Aluthge, N D; Ramirez Ramirez, H A; Christensen, D A; Mutsvangwa, T; Penner, G B; Fernando, S C

    2018-01-01

    The effects of partial replacement of a barley-based concentrate with flaxseed-based products on the rumen bacterial population of lactating Holstein dairy cows were evaluated. Treatments fed were CONT, a normal diet that included barley silage, alfalfa hay and a barley-based concentrate that contained no flaxseed or faba beans; FLAX, inclusion of a nonextruded flaxseed-based product containing 55·0% flaxseed, 37·8% field peas and 6·9% alfalfa; EXT, similar to FLAX, but the product was extruded and EXTT, similar to FLAX, but product was extruded and field peas were replaced by high-tannin faba beans. The rumen bacterial population was evaluated by utilizing 16S rRNA gene sequencing. Most abundant phyla, families and genera were unaffected. However, some taxa were affected; for example, unsaturated fatty acid content was negatively correlated with Clostridiaceae, and tannin content was negatively correlated with BS11 and Paraprevotellaceae. Predominant rumen bacterial taxa were not affected, but the abundance of some taxa found in lower proportions shifted, possibly due to sensitivity to unsaturated fatty acids or tannins. Flaxseed-based products were effective for partially replacing barley-based concentrate in rations of lactating dairy cows. No negative effects of these products were observed on the abundance of predominant rumen bacterial taxa, with only minor shifts in less abundant bacteria. © 2017 The Authors. Journal of Applied Microbiology published by John Wiley & Sons Ltd on behalf of Society for Applied Microbiology.

  1. Molecular basis of perinatal hypophosphatasia with tissue-nonspecific alkaline phosphatase bearing a conservative replacement of valine by alanine at position 406. Structural importance of the crown domain.

    Science.gov (United States)

    Numa, Natsuko; Ishida, Yoko; Nasu, Makiko; Sohda, Miwa; Misumi, Yoshio; Noda, Tadashi; Oda, Kimimitsu

    2008-06-01

    Hypophosphatasia, a congenital metabolic disease related to the tissue-nonspecific alkaline phosphatase gene (TNSALP), is characterized by reduced serum alkaline phosphatase levels and defective mineralization of hard tissues. A replacement of valine with alanine at position 406, located in the crown domain of TNSALP, was reported in a perinatal form of hypophosphatasia. To understand the molecular defect of the TNSALP (V406A) molecule, we examined this missense mutant protein in transiently transfected COS-1 cells and in stable CHO-K1 Tet-On cells. Compared with the wild-type enzyme, the mutant protein showed a markedly reduced alkaline phosphatase activity. This was not the result of defective transport and resultant degradation of TNSALP (V406A) in the endoplasmic reticulum, as the majority of newly synthesized TNSALP (V406A) was conveyed to the Golgi apparatus and incorporated into a cold detergent insoluble fraction (raft) at a rate similar to that of the wild-type TNSALP. TNSALP (V406A) consisted of a dimer, as judged by sucrose gradient centrifugation, suggestive of its proper folding and correct assembly, although this mutant showed increased susceptibility to digestion by trypsin or proteinase K. When purified as a glycosylphosphatidylinositol-anchorless soluble form, the mutant protein exhibited a remarkably lower Kcat/Km value compared with that of the wild-type TNSALP. Interestingly, leucine and isoleucine, but not phenylalanine, were able to substitute for valine, pointing to the indispensable role of residues with a longer aliphatic side chain at position 406 of TNSALP. Taken together, this particular mutation highlights the structural importance of the crown domain with respect to the catalytic function of TNSALP.

  2. Submicron sized ultra-high molecular weight polyethylene wear particle analysis from revised SB Charité III total disc replacements.

    Science.gov (United States)

    Punt, Ilona; Baxter, Ryan; van Ooij, André; Willems, Paul; van Rhijn, Lodewijk; Kurtz, Steven; Steinbeck, Marla

    2011-09-01

    Submicron sized particles are frequently observed in retrieved total hip and knee periprosthetic tissues and appear to be critical in the activation of the phagocytic inflammatory response. In this paper the concentration, size and shape of ultra-high molecular weight polyethylene (UHMWPE) wear particles between 0.05 and 2.00μm were determined after isolation from periprosthetic tissues from retrieved lumbar SB Charité III total disc replacements (TDR) using scanning electron microscopy (SEM). For comparison, UHMWPE wear particles were isolated from γ-radiation-air sterilized total hip arthroplasty (THA) revision tissues. The mean concentration of UHMWPE particles in TDR tissues was 1.6×10(9)g(-1)tissue (range 1.3-2.0), which was significantly lower than the concentration of 2.3×10(9)g(-1) THA revision tissue (range 1.8-3.2) (P=0.03). The mean particle size (equivalent circular diameter: TDR, 0.46μm; THA 0.53μm, P=0.60) and mean shape were comparable between TDR and THA (aspect ratio: TDR, 1.89; THA, 1.99, P=0.35; roundness: TDR, 0.58; THA, 0.56, P=0.35). However, the TDR particles tended to be smaller and more round. Although no correlations were found between visible damage to the UHMWPE core and the concentration or shape of the UHMWPE particles, a positive correlation was found between increasing particle size and increasing rim penetration of the TDR core (P=0.04). The presence of UHMWPE particles of similar size and shape in TDR tissue, albeit lower in concentration, might explain why, unlike THA, pain rather than osteolysis is the major reason for revision surgery. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  3. Knowledge, attitude and practices of institution-based dentists toward nicotine replacement therapy

    Directory of Open Access Journals (Sweden)

    Swikant Shah

    2017-01-01

    Full Text Available Background: Dental institutions provide very good platform to educate budding dentists to inculcate the habit of tobacco cessation counseling, including nicotine replacement therapy (NRT. Aims: The aim of this study is to assess and compare the knowledge, attitude, and practice of institutionally attached postgraduate students and faculty members of the dental profession toward NRT. Methods: For a cross-sectional survey among 201 participants from four dental colleges in Odisha, India, a 28-item questionnaire was developed, subdivided into four categories: demographic details, assessment of NRT knowledge (21-item, assessment of attitude (5-item, practice (1-item with 4 subgroup questions, and 1-item assessing barriers. Statistical Analysis Used: Data were analyzed using descriptive statistics, Chi-square test, and multiple logistic regression. Results: Only one-third of participants were aware of the dosage, mechanism of action, pharmacology, duration of the prescription, brand name, side effects, contraindications, and availability. Around two-third of participants who claimed to practice NRT, agreed to follow up the patients whom they prescribed NRT. Half of the study participants reported that they do not keep a record of these patients. Around 10% of respondents practicing NRT were confident enough to practice it without facing any problem. Major barriers for practicing NRT was found to be a lack of awareness (54.22% followed by availability and bitter taste. The total knowledge score was found to be the strongest predictor of practicing NRT in multiple logistic regression. Conclusion: Lack of detailed knowledge regarding NRT reduces the chance of practicing inspite of having a positive attitude among institutionally attached dentists.

  4. Forcefields based molecular modeling on the mechanical and physical properties of emeraldine base polyaniline

    NARCIS (Netherlands)

    Chen, X.; Yuan, C.A.; Wong, K.Y.; Zhang, G.Q.

    2010-01-01

    Molecular dynamics (MD) and molecular mechanical (MM) analysis are carried out to provide reliable and accurate model for emeraldine base polyaniline. This study validate the forcefields and model with the physical and mechanical properties of the polyaniline. The temperature effects on non-bond

  5. Use of Renal Replacement Therapy May Influence Graft Outcomes following Liver Transplantation for Acute Liver Failure: A Propensity-Score Matched Population-Based Retrospective Cohort Study.

    Science.gov (United States)

    Knight, Stephen R; Oniscu, Gabriel C; Devey, Luke; Simpson, Kenneth J; Wigmore, Stephen J; Harrison, Ewen M

    2016-01-01

    Acute kidney injury is associated with a poor prognosis in acute liver failure but little is known of outcomes in patients undergoing transplantation for acute liver failure who require renal replacement therapy. A retrospective analysis of the United Kingdom Transplant Registry was performed (1 January 2001-31 December 2011) with patient and graft survival determined using Kaplan-Meier methods. Cox proportional hazards models were used together with propensity-score based full matching on renal replacement therapy use. Three-year patient and graft survival for patients receiving renal replacement therapy were 77.7% and 72.6% compared with 85.1% and 79.4% for those not requiring renal replacement therapy (Prenal replacement therapy was a predictor of both patient death (hazard ratio (HR) 1.59, 95% CI 1.01-2.50, P = 0.044) but not graft loss (HR 1.39, 95% CI 0.92-2.10, P = 0.114). In groups fully matched on baseline covariates, those not receiving renal replacement therapy with a serum creatinine greater than 175 μmol/L had a significantly worse risk of graft failure than those receiving renal replacement therapy. In patients being transplanted for acute liver failure, use of renal replacement therapy is a strong predictor of patient death and graft loss. Those not receiving renal replacement therapy with an elevated serum creatinine may be at greater risk of early graft failure than those receiving renal replacement therapy. A low threshold for instituting renal replacement therapy may therefore be beneficial.

  6. Pea proteins based food products as meat replacers: the Profetas concept

    NARCIS (Netherlands)

    Jongen, W.M.F.; Meerdink, G.

    2001-01-01

    Profetas (Protein Foods, Environment, Technology and Society) is a Dutch trans-disciplinary research programme, aiming to develop more sustainable food systems. The central theme of the programme is the question: is a transition feasible from a diet based primarily on animal proteins to a diet based

  7. Organization of a radioisotope based molecular biology laboratory

    International Nuclear Information System (INIS)

    2006-12-01

    Polymerase chain reaction (PCR) has revolutionized the application of molecular techniques to medicine. Together with other molecular biology techniques it is being increasingly applied to human health for identifying prognostic markers and drug resistant profiles, developing diagnostic tests and genotyping systems and for treatment follow-up of certain diseases in developed countries. Developing Member States have expressed their need to also benefit from the dissemination of molecular advances. The use of radioisotopes, as a step in the detection process or for increased sensitivity and specificity is well established, making it ideally suitable for technology transfer. Many molecular based projects using isotopes for detecting and studying micro organisms, hereditary and neoplastic diseases are received for approval every year. In keeping with the IAEA's programme, several training activities and seminars have been organized to enhance the capabilities of developing Member States to employ in vitro nuclear medicine technologies for managing their important health problems and for undertaking related basic and clinical research. The background material for this publication was collected at training activities and from feedback received from participants at research and coordination meetings. In addition, a consultants' meeting was held in June 2004 to compile the first draft of this report. Previous IAEA TECDOCS, namely IAEA-TECDOC-748 and IAEA-TECDOC-1001, focused on molecular techniques and their application to medicine while the present publication provides information on organization of the laboratory, quality assurance and radio-safety. The technology has specific requirements of the way the laboratory is organized (e.g. for avoiding contamination and false positives in PCR) and of quality assurance in order to provide accurate information to decision makers. In addition while users of the technology accept the scientific rationale of using radio

  8. Knee Replacement

    Science.gov (United States)

    ... days. Medications prescribed by your doctor should help control pain. During the hospital stay, you'll be encouraged to move your ... exercise your new knee. After you leave the hospital, you'll continue physical ... mobility and a better quality of life. And most knee replacements can be ...

  9. Three-dimensional computer graphics-based ankle morphometry with computerized tomography for total ankle replacement design and positioning.

    Science.gov (United States)

    Kuo, Chien-Chung; Lu, Hsuan-Lun; Leardini, Alberto; Lu, Tung-Wu; Kuo, Mei-Ying; Hsu, Horng-Chaung

    2014-05-01

    Morphometry of the bones of the ankle joint is important for the design of joint replacements and their surgical implantations. However, very little three-dimensional (3D) data are available and not a single study has addressed the Chinese population. Fifty-eight fresh frozen Chinese cadaveric ankle specimens, 26 females, and 32 males, were CT-scanned in the neutral position and their 3D computer graphics-based models were reconstructed. The 3D morphology of the distal tibia/fibula segment and the full talus was analyzed by measuring 31 parameters, defining the relevant dimensions, areas, and volumes from the models. The measurements were compared statistically between sexes and with previously reported data from Caucasian subjects. The results showed that, within a general similarity of ankle morphology between the current Chinese and previous Caucasian subjects groups, there were significant differences in 9 out of the 31 parameters analyzed. From a quantitative comparison with available prostheses designed for the Caucasian population, few of these designs have both tibial and talar components suitable in dimension for the Chinese population. The current data will be helpful for the sizing, design, and surgical positioning of ankle replacements and for surgical instruments, especially for the Chinese population. Copyright © 2013 Wiley Periodicals, Inc.

  10. Molecular polarization potential maps of the nucleic acid bases

    International Nuclear Information System (INIS)

    Alkorta, I.; Perez, J.J.

    1996-01-01

    Ab initio calculations at the SCF level were carried out to compute the polarization potential map NM of the nucleic acid bases: cytosine, thymine, uracil, adedine, and guanine. For this purpose, the Dunning's 9s5p basis set contracted to a split-valence, was selected to perform the calculations. The molecular polarization potential (MPP) at each point was evaluated by the difference between the interaction energy of the molecule with a unit point charge and the molecular electrostatic potential (MEP) at that point. MEPS and MPPS for the different molecules were computed with a density of 5 points/Angstrom 2 on the van der Waals surface of each molecule, defined using the van der Waals radii. Due to the symmetry of the molecules, only half the points were computed. The total number of points calculated was 558 for cytosine, 621 for thymine, 526 for uracil, 666 for adenine, and 699 for guanine. The results of these calculations are analyzed in terms of their implications on the molecular interactions between pairs of nucleic acid bases. 23 refs., 5 figs., 1 tab

  11. The Alberta Hip and Knee Replacement Project: a model for health technology assessment based on comparative effectiveness of clinical pathways.

    Science.gov (United States)

    Gooch, Katherine L; Smith, Douglas; Wasylak, Tracy; Faris, Peter D; Marshall, Deborah A; Khong, Hoa; Hibbert, Julie E; Parker, Robyn D; Zernicke, Ronald F; Beaupre, Lauren; Pearce, Tim; Johnston, D W C; Frank, Cyril B

    2009-04-01

    The Alberta Hip and Knee Replacement Project developed a new evidence-based clinical pathway (NCP) for total hip (THR) and knee (TKR) replacement. The aim was to facilitate the delivery of services in a timely and cost-effective manner while achieving the highest quality of care for the patient across the full continuum of care from patient referral to an orthopedic surgeon through surgery, recovery, and rehabilitation. The purpose of this article is to provide an overview of the study design, rationale, and execution of this project as a model for health technology assessment based on comparative effectiveness of alternative clinical pathways. A pragmatic randomized controlled trial study design was used to evaluate the NCP compared with the standard of care (SOC) for these procedures. The pragmatic study design was selected as a rigorous approach to produce high quality evidence suitable for informing decisions between relevant interventions in real clinical practice. The NCP was evaluated in three of the nine regional health authorities (RHAs) in Alberta with dedicated central intake clinics offering multidisciplinary care teams, constituting 80 percent of THR and TKR surgeries performed annually in Alberta. Patients were identified in the offices of twenty orthopedic surgeons who routinely performed THR or TKR surgeries. Evaluation outcome measures were based on the six dimensions of the Alberta Quality Matrix for Health (AQMH): acceptability, accessibility, appropriateness, effectiveness, efficiency and safety. Data were collected prospectively through patient self-completed questionnaires at baseline and 3 and 12 months after surgery, ambulatory and inpatient chart reviews, and electronic administrative data. The trial design was successful in establishing similar groups for rigorous evaluation. Of the 4,985 patients invited to participate, 69 percent of patients consented. A total of 3,434 patients were randomized: 1,712 to SOC and 1,722 to the NCP. The

  12. Replacing fossil based PET with biobased PEF; proess analysis, energy and GHG balance

    NARCIS (Netherlands)

    Eerhart, A.J.J.E.|info:eu-repo/dai/nl/341358541; Faaij, A.P.C.|info:eu-repo/dai/nl/10685903X; Patel, M.K.|info:eu-repo/dai/nl/18988097X

    2012-01-01

    An energy and greenhouse gas (GHG) balance study was performed on the production of the bioplastic polyethylene furandicarboxylate (PEF) starting from corn based fructose. The goal of the study was to analyze and to translate experimental data on the catalytic dehydration of fructose to a simulation

  13. Prototype base curve attachment for the topographer: what will replace the vanishing radiuscope?

    Science.gov (United States)

    Elder, Keshia S; Benjamin, William J

    2009-03-01

    With the disappearance of the radiuscope, alternative methods must be developed to accurately measure gas-permeable (GP) lenses. The purpose of this study was to design, manufacture, and test a novel attachment for the evaluation of spherical base curves of GP rigid contact lenses using a corneal topographer. A topographer attachment was devised with the intent of measuring the surface radii of GP lenses. A front-surface mirror was fixed at a 45 degrees angle above a hemispherical GP lens mount taken from a radiuscope. The device was set in the chin rest of a Humphrey Atlas topographer (Carl Zeiss Meditec, Inc., Jena, Germany) such that the image from the back of a GP surface was focused. The base curve radii of 9 rigid polymer buttons nominally ranging from 5.00 mm to 9.00 mm in 0.5-mm steps were measured 3 times with a Neitz Auto CG (Neitz Instruments Co., Ltd., Tokyo, Japan), Reichert Radiuscope (Reichert Ophthalmic Instruments, Depew, New York), and Humphrey Atlas topographer using the base curve (BC) attachment. An analysis of variance with replication and without interaction, using the main effects of measurement method (n = 5) and nominal button radius (n = 9), found that there was no statistically significant effect of the base curve measurement method (F[4, 122] = 1.23; P = 0.303), although there was a statistically significant effect of nominal button radius (F[8, 122] = 4.70; P = 0.003). Although the optical system of the corneal topographer was designed for measurement of convex surfaces, measurement of base curve radii from concave surfaces was performed without a correction factor using the prototype attachment. The mean SimK and Axial radii were within the tolerance for GP base curve radius, 0.05 mm, cited in ANSI Z80.20-2004 and ISO 18369-2:2006. Thus, the clinical feasibility of this prototype BC attachment to support measurement of spherical base curve radii for GP lenses by a corneal topographer was demonstrated.

  14. Application of DEN refinement and automated model building to a difficult case of molecular-replacement phasing: the structure of a putative succinyl-diaminopimelate desuccinylase from Corynebacterium glutamicum.

    Science.gov (United States)

    Brunger, Axel T; Das, Debanu; Deacon, Ashley M; Grant, Joanna; Terwilliger, Thomas C; Read, Randy J; Adams, Paul D; Levitt, Michael; Schröder, Gunnar F

    2012-04-01

    Phasing by molecular replacement remains difficult for targets that are far from the search model or in situations where the crystal diffracts only weakly or to low resolution. Here, the process of determining and refining the structure of Cgl1109, a putative succinyl-diaminopimelate desuccinylase from Corynebacterium glutamicum, at ∼3 Å resolution is described using a combination of homology modeling with MODELLER, molecular-replacement phasing with Phaser, deformable elastic network (DEN) refinement and automated model building using AutoBuild in a semi-automated fashion, followed by final refinement cycles with phenix.refine and Coot. This difficult molecular-replacement case illustrates the power of including DEN restraints derived from a starting model to guide the movements of the model during refinement. The resulting improved model phases provide better starting points for automated model building and produce more significant difference peaks in anomalous difference Fourier maps to locate anomalous scatterers than does standard refinement. This example also illustrates a current limitation of automated procedures that require manual adjustment of local sequence misalignments between the homology model and the target sequence.

  15. Clustering the Orion B giant molecular cloud based on its molecular emission

    Science.gov (United States)

    Bron, Emeric; Daudon, Chloé; Pety, Jérôme; Levrier, François; Gerin, Maryvonne; Gratier, Pierre; Orkisz, Jan H.; Guzman, Viviana; Bardeau, Sébastien; Goicoechea, Javier R.; Liszt, Harvey; Öberg, Karin; Peretto, Nicolas; Sievers, Albrecht; Tremblin, Pascal

    2018-02-01

    Context. Previous attempts at segmenting molecular line maps of molecular clouds have focused on using position-position-velocity data cubes of a single molecular line to separate the spatial components of the cloud. In contrast, wide field spectral imaging over a large spectral bandwidth in the (sub)mm domain now allows one to combine multiple molecular tracers to understand the different physical and chemical phases that constitute giant molecular clouds (GMCs). Aims: We aim at using multiple tracers (sensitive to different physical processes and conditions) to segment a molecular cloud into physically/chemically similar regions (rather than spatially connected components), thus disentangling the different physical/chemical phases present in the cloud. Methods: We use a machine learning clustering method, namely the Meanshift algorithm, to cluster pixels with similar molecular emission, ignoring spatial information. Clusters are defined around each maximum of the multidimensional probability density function (PDF) of the line integrated intensities. Simple radiative transfer models were used to interpret the astrophysical information uncovered by the clustering analysis. Results: A clustering analysis based only on the J = 1-0 lines of three isotopologues of CO proves sufficient to reveal distinct density/column density regimes (nH 100 cm-3, 500 cm-3, and >1000 cm-3), closely related to the usual definitions of diffuse, translucent and high-column-density regions. Adding two UV-sensitive tracers, the J = 1-0 line of HCO+ and the N = 1-0 line of CN, allows us to distinguish two clearly distinct chemical regimes, characteristic of UV-illuminated and UV-shielded gas. The UV-illuminated regime shows overbright HCO+ and CN emission, which we relate to a photochemical enrichment effect. We also find a tail of high CN/HCO+ intensity ratio in UV-illuminated regions. Finer distinctions in density classes (nH 7 × 103 cm-3, 4 × 104 cm-3) for the densest regions are also

  16. Forecasting overhaul or replacement intervals based on estimated system failure intensity

    Science.gov (United States)

    Gannon, James M.

    1994-12-01

    System reliability can be expressed in terms of the pattern of failure events over time. Assuming a nonhomogeneous Poisson process and Weibull intensity function for complex repairable system failures, the degree of system deterioration can be approximated. Maximum likelihood estimators (MLE's) for the system Rate of Occurrence of Failure (ROCOF) function are presented. Evaluating the integral of the ROCOF over annual usage intervals yields the expected number of annual system failures. By associating a cost of failure with the expected number of failures, budget and program policy decisions can be made based on expected future maintenance costs. Monte Carlo simulation is used to estimate the range and the distribution of the net present value and internal rate of return of alternative cash flows based on the distributions of the cost inputs and confidence intervals of the MLE's.

  17. Boron-coated straws as a replacement for {sup 3}He-based neutron detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lacy, Jeffrey L., E-mail: jlacy@proportionaltech.com [Proportional Technologies, Inc., 8022 El Rio Street, Houston, TX 77054 (United States); Athanasiades, Athanasios; Sun, Liang; Martin, Christopher S.; Lyons, Tom D.; Foss, Michael A.; Haygood, Hal B. [Proportional Technologies, Inc., 8022 El Rio Street, Houston, TX 77054 (United States)

    2011-10-01

    US and international government efforts to equip major seaports with large area neutron detectors, aimed to intercept the smuggling of nuclear materials, have precipitated a critical shortage of {sup 3}He gas. It is estimated that the annual demand of {sup 3}He for US security applications alone is more than the worldwide supply. This is strongly limiting the prospects of neutron science, safeguards, and other applications that rely heavily on {sup 3}He-based detectors. Clearly, alternate neutron detection technologies that can support large sensitive areas, and have low gamma sensitivity and low cost must be developed. We propose a low-cost technology based on long copper tubes (straws), coated on the inside with a thin layer of {sup 10}B-enriched boron carbide ({sup 10}B{sub 4}C). In addition to the high abundance of boron on Earth and low cost of {sup 10}B enrichment, the boron-coated straw (BCS) detector offers distinct advantages over conventional {sup 3}He-based detectors, and alternate technologies such as {sup 10}BF{sub 3} tubes and {sup 10}B-coated rigid tubes. These include better distribution inside moderator assemblies, many-times faster electronic signals, no pressurization, improved gamma-ray rejection, no toxic or flammable gases, and ease of serviceability. We present the performance of BCS detectors dispersed in a solid plastic moderator to address the need for portal monitoring. The design adopts the outer dimensions of currently deployed {sup 3}He-based monitors, but takes advantage of the small BCS diameter to achieve a more uniform distribution of neutron converter throughout the moderating material. We show that approximately 63 BCS detectors, each 205 cm long, distributed inside the moderator, can match or exceed the detection efficiency of typical monitors fitted with a 5 cm diameter {sup 3}He tube, 187 cm long, pressurized to 3 atm.

  18. Boron-coated straws as a replacement for 3He-based neutron detectors

    International Nuclear Information System (INIS)

    Lacy, Jeffrey L.; Athanasiades, Athanasios; Sun, Liang; Martin, Christopher S.; Lyons, Tom D.; Foss, Michael A.; Haygood, Hal B.

    2011-01-01

    US and international government efforts to equip major seaports with large area neutron detectors, aimed to intercept the smuggling of nuclear materials, have precipitated a critical shortage of 3 He gas. It is estimated that the annual demand of 3 He for US security applications alone is more than the worldwide supply. This is strongly limiting the prospects of neutron science, safeguards, and other applications that rely heavily on 3 He-based detectors. Clearly, alternate neutron detection technologies that can support large sensitive areas, and have low gamma sensitivity and low cost must be developed. We propose a low-cost technology based on long copper tubes (straws), coated on the inside with a thin layer of 10 B-enriched boron carbide ( 10 B 4 C). In addition to the high abundance of boron on Earth and low cost of 10 B enrichment, the boron-coated straw (BCS) detector offers distinct advantages over conventional 3 He-based detectors, and alternate technologies such as 10 BF 3 tubes and 10 B-coated rigid tubes. These include better distribution inside moderator assemblies, many-times faster electronic signals, no pressurization, improved gamma-ray rejection, no toxic or flammable gases, and ease of serviceability. We present the performance of BCS detectors dispersed in a solid plastic moderator to address the need for portal monitoring. The design adopts the outer dimensions of currently deployed 3 He-based monitors, but takes advantage of the small BCS diameter to achieve a more uniform distribution of neutron converter throughout the moderating material. We show that approximately 63 BCS detectors, each 205 cm long, distributed inside the moderator, can match or exceed the detection efficiency of typical monitors fitted with a 5 cm diameter 3 He tube, 187 cm long, pressurized to 3 atm.

  19. Boron-coated straws as a replacement for 3He-based neutron detectors

    Science.gov (United States)

    Lacy, Jeffrey L.; Athanasiades, Athanasios; Sun, Liang; Martin, Christopher S.; Lyons, Tom D.; Foss, Michael A.; Haygood, Hal B.

    2011-10-01

    US and international government efforts to equip major seaports with large area neutron detectors, aimed to intercept the smuggling of nuclear materials, have precipitated a critical shortage of 3He gas. It is estimated that the annual demand of 3He for US security applications alone is more than the worldwide supply. This is strongly limiting the prospects of neutron science, safeguards, and other applications that rely heavily on 3He-based detectors. Clearly, alternate neutron detection technologies that can support large sensitive areas, and have low gamma sensitivity and low cost must be developed. We propose a low-cost technology based on long copper tubes (straws), coated on the inside with a thin layer of 10B-enriched boron carbide ( 10B 4C). In addition to the high abundance of boron on Earth and low cost of 10B enrichment, the boron-coated straw (BCS) detector offers distinct advantages over conventional 3He-based detectors, and alternate technologies such as 10BF 3 tubes and 10B-coated rigid tubes. These include better distribution inside moderator assemblies, many-times faster electronic signals, no pressurization, improved gamma-ray rejection, no toxic or flammable gases, and ease of serviceability. We present the performance of BCS detectors dispersed in a solid plastic moderator to address the need for portal monitoring. The design adopts the outer dimensions of currently deployed 3He-based monitors, but takes advantage of the small BCS diameter to achieve a more uniform distribution of neutron converter throughout the moderating material. We show that approximately 63 BCS detectors, each 205 cm long, distributed inside the moderator, can match or exceed the detection efficiency of typical monitors fitted with a 5 cm diameter 3He tube, 187 cm long, pressurized to 3 atm.

  20. Final Environmental Assessment: Replacement Joint Force Headquarters Building, Hanscom Air Force Base Massachusetts

    Science.gov (United States)

    2010-01-22

    inspirational musical adaptation of the Charles Dickens classic opens at Concord’s Emerson Umbrella Center for the Arts at 7:30 p.m. tomorrow. Though most...www.new- lifefinearts.org. ONE STAGE, ONE MAN: Dickens himself was quite the rage when he gave solo dramatic readings of ‘‘A Christmas Carol’’ to...based on the Dickens classic. 2 W1 W1 -2 21:40 P u b lic at io n D at e: 12 /1 0/ 20 09 A d N um be r: 20 00 26 83 37 In se rt io n N um be r

  1. Molecular Bases Underlying the Hepatoprotective Effects of Coffee

    Directory of Open Access Journals (Sweden)

    Federico Salomone

    2017-01-01

    Full Text Available Coffee is the most consumed beverage worldwide. Epidemiological studies with prospective cohorts showed that coffee intake is associated with reduced cardiovascular and all-cause mortality independently of caffeine content. Cohort and case-control studies reported an inverse association between coffee consumption and the degree of liver fibrosis as well as the development of liver cancer. Furthermore, the beneficial effects of coffee have been recently confirmed by large meta-analyses. In the last two decades, various in vitro and in vivo studies evaluated the molecular determinants for the hepatoprotective effects of coffee. In the present article, we aimed to critically review experimental evidence regarding the active components and the molecular bases underlying the beneficial role of coffee against chronic liver diseases. Almost all studies highlighted the beneficial effects of this beverage against liver fibrosis with the most solid results indicating a pivot role for both caffeine and chlorogenic acids. In particular, in experimental models of fibrosis, caffeine was shown to inhibit hepatic stellate cell activation by blocking adenosine receptors, and emerging evidence indicated that caffeine may also favorably impact angiogenesis and hepatic hemodynamics. On the other side, chlorogenic acids, potent phenolic antioxidants, suppress liver fibrogenesis and carcinogenesis by reducing oxidative stress and counteract steatogenesis through the modulation of glucose and lipid homeostasis in the liver. Overall, these molecular insights may have translational significance and suggest that coffee components need clinical evaluation.

  2. Acidity constants from DFT-based molecular dynamics simulations

    International Nuclear Information System (INIS)

    Sulpizi, Marialore; Sprik, Michiel

    2010-01-01

    In this contribution we review our recently developed method for the calculation of acidity constants from density functional theory based molecular dynamics simulations. The method is based on a half reaction scheme in which protons are formally transferred from solution to the gas phase. The corresponding deprotonation free energies are computed from the vertical energy gaps for insertion or removal of protons. Combined to full proton transfer reactions, the deprotonation energies can be used to estimate relative acidity constants and also the Broensted pK a when the deprotonation free energy of a hydronium ion is used as a reference. We verified the method by investigating a series of organic and inorganic acids and bases spanning a wide range of pK a values (20 units). The thermochemical corrections for the biasing potentials assisting and directing the insertion are discussed in some detail.

  3. Fullerene-based Anchoring Groups for Molecular Electronics

    DEFF Research Database (Denmark)

    Martin, Christian A.; Ding, Dapeng; Sørensen, Jakob Kryger

    2008-01-01

    We present results on a new fullerene-based anchoring group for molecular electronics. Using lithographic mechanically controllable break junctions in vacuum we have determined the conductance and stability of single-molecule junctions of 1,4-bis(fullero[c]pyrrolidin-1-yl)benzene. The compound can...... be self-assembled from solution and has a low-bias conductance of 3 × 10-4 G0. Compared to 1,4-benzenedithiol the fullerene-anchored molecule exhibits a considerably lower conductance spread. In addition, the signature of the new compound in histograms is more significant than that of 1,4-benzenediamine...

  4. Aptamer-based molecular recognition for biosensor development.

    Science.gov (United States)

    Zhou, Jing; Battig, Mark R; Wang, Yong

    2010-11-01

    Nucleic acid aptamers are an emerging class of synthetic ligands and have recently attracted significant attention in numerous fields. One is in biosensor development. In principle, nucleic acid aptamers can be discovered to recognize any molecule of interest with high affinity and specificity. In addition, unlike most ligands evolved in nature, synthetic nucleic acid aptamers are usually tolerant of harsh chemical, physical, and biological conditions. These distinguished characteristics make aptamers attractive molecular recognition ligands for biosensing applications. This review first concisely introduces methods for aptamer discovery including upstream selection and downstream truncation, then discusses aptamer-based biosensor development from the viewpoint of signal production.

  5. Molecular tools for the construction of peptide-based materials.

    Science.gov (United States)

    Ramakers, B E I; van Hest, J C M; Löwik, D W P M

    2014-04-21

    Proteins and peptides are fundamental components of living systems where they play crucial roles at both functional and structural level. The versatile biological properties of these molecules make them interesting building blocks for the construction of bio-active and biocompatible materials. A variety of molecular tools can be used to fashion the peptides necessary for the assembly of these materials. In this tutorial review we shall describe five of the main techniques, namely solid phase peptide synthesis, native chemical ligation, Staudinger ligation, NCA polymerisation, and genetic engineering, that have been used to great effect for the construction of a host of peptide-based materials.

  6. Kinetic-molecular theory optimization algorithm based on Kent chaotic mapping

    Science.gov (United States)

    Gong, Huguang; Fan, Chaodong; Ouyang, Bo

    2017-08-01

    Aiming at the shortage that Kinetic-molecular theory optimization algorithm (KMTOA) is more likely to show premature convergence and the accuracy of searching for the optimum needs to be improved, a Kinetic-molecular theory optimization algorithm (KCKMTOA) based on Kent chaotic mapping was proposed. The algorithm utilizes the characteristics of chaotic algorithm, such as ergodicity, non-periodicity, randomness etc. When algorithm falls into the local optimum, Kent chaotic mapping is used to perform chaotic search around the local optimum to replace partial particles of original particle swarm in order to jump out from the local optimum to find the global optimum. As the algorithm is carried out, the radius of chaotic search decreases linearly, so as to ensure the precision of searching and speed of the algorithm. 20 classical test functions are taken into consideration in simulation experiments. After making a comprehensive comparison for the performance of searching for the optimum of DE, GA, QPSO, KMTOA and KCKMTOA in 20 classical test functions, the results of experiments show that this algorithm has obvious advantages in precision, speed and robustness optimization etc.

  7. Assessment of the Swedish EQ-5D experience-based value sets in a total hip replacement population.

    Science.gov (United States)

    Nemes, Szilárd; Burström, Kristina; Zethraeus, Niklas; Eneqvist, Ted; Garellick, Göran; Rolfson, Ola

    2015-12-01

    All patients undergoing elective total hip replacement (THR) in Sweden are asked to complete a survey, including the EQ-5D. Thus far, EQ-5D values have been presented using the UK TTO value set based on hypothetical values. Shift to the use of the recently introduced Swedish experience-based value set, derived from a representative Swedish population, is an appealing alternative. To investigate how accurate the Swedish experience-based VAS value set predicts observed EQ VAS values and to compare correlations between Swedish and UK value sets including two provisional value sets derived from the THR population. Pre- and one-year postoperative data from 56,062 THR patients from the Swedish Hip Arthroplasty Register were used. Agreement between the observed and the predicted EQ VAS values was assessed with correlation. Based on pre- and postoperative data, we constructed two provisional VAS value sets. Correlations between observed and calculated values using the Swedish VAS value set were moderate (r = 0.46) in preoperative data and high (r = 0.72) in postoperative data. Correlations between UK and register-based value sets were constantly lower compared to Swedish value sets. Register-based values and Swedish values were highly correlated. The Swedish value sets are more accurate in terms of representation of the Swedish THR patients than the currently used UK TTO value set. We find it feasible to use the experience-based Swedish value sets for further presentation of EQ-5D values in the Swedish THR population.

  8. Plasmon-Based Colorimetric Nanosensors for Ultrasensitive Molecular Diagnostics.

    Science.gov (United States)

    Tang, Longhua; Li, Jinghong

    2017-07-28

    Colorimetric detection of target analytes with high specificity and sensitivity is of fundamental importance to clinical and personalized point-of-care diagnostics. Because of their extraordinary optical properties, plasmonic nanomaterials have been introduced into colorimetric sensing systems, which provide significantly improved sensitivity in various biosensing applications. Here we review the recent progress on these plasmonic nanoparticles-based colorimetric nanosensors for ultrasensitive molecular diagnostics. According to their different colorimetric signal generation mechanisms, these plasmonic nanosensors are classified into two categories: (1) interparticle distance-dependent colorimetric assay based on target-induced forming cross-linking assembly/aggregate of plasmonic nanoparticles; and (2) size/morphology-dependent colorimetric assay by target-controlled growth/etching of the plasmonic nanoparticles. The sensing fundamentals and cutting-edge applications will be provided for each of them, particularly focusing on signal generation and/or amplification mechanisms that realize ultrasensitive molecular detection. Finally, we also discuss the challenge and give our future perspective in this emerging field.

  9. Stable Molecular Diodes Based on π-π Interactions of the Molecular Frontier Orbitals with Graphene Electrodes.

    Science.gov (United States)

    Song, Peng; Guerin, Sarah; Tan, Sherman Jun Rong; Annadata, Harshini Venkata; Yu, Xiaojiang; Scully, Micheál; Han, Ying Mei; Roemer, Max; Loh, Kian Ping; Thompson, Damien; Nijhuis, Christian A

    2018-03-01

    In molecular electronics, it is important to control the strength of the molecule-electrode interaction to balance the trade-off between electronic coupling strength and broadening of the molecular frontier orbitals: too strong coupling results in severe broadening of the molecular orbitals while the molecular orbitals cannot follow the changes in the Fermi levels under applied bias when the coupling is too weak. Here, a platform based on graphene bottom electrodes to which molecules can bind via π-π interactions is reported. These interactions are strong enough to induce electronic function (rectification) while minimizing broadening of the molecular frontier orbitals. Molecular tunnel junctions are fabricated based on self-assembled monolayers (SAMs) of Fc(CH 2 ) 11 X (Fc = ferrocenyl, X = NH 2 , Br, or H) on graphene bottom electrodes contacted to eutectic alloy of gallium and indium top electrodes. The Fc units interact more strongly with graphene than the X units resulting in SAMs with the Fc at the bottom of the SAM. The molecular diodes perform well with rectification ratios of 30-40, and they are stable against bias stressing under ambient conditions. Thus, tunnel junctions based on graphene with π-π molecule-electrode coupling are promising platforms to fabricate stable and well-performing molecular diodes. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. A quantitative assessment of the risk of transmission of bovine spongiform encephalopathy by tallow-based calf milk-replacer

    DEFF Research Database (Denmark)

    Paisley, Larry; Hostrup-Pedersen, J.

    2004-01-01

    A Monte Carlo simulation model was constructed to assess the risk of BSE transmission to calves by calf milk-replacer (CMR). We assumed that any BSE infectivity in the CMR would be associated with the allowable levels of impurities in tallow used to manufacture the milk-replacer. Simulations used...

  11. Molecular similarity-based predictions of the Tox21 screening outcome

    Directory of Open Access Journals (Sweden)

    Malgorzata Natalia Drwal

    2015-07-01

    Full Text Available To assess the toxicity of new chemicals and drugs, regulatory agencies require in vivo testing for many toxic endpoints, resulting in millions of animal experiments conducted each year. However, following the Replace, Reduce, Refine (3R principle, the development and optimization of alternative methods, in particular in silico methods, has been put into focus in the recent years. It is generally acknowledged that the more complex a toxic endpoint, the more difficult it is to model. Therefore, computational toxicology is shifting from modelling general and complex endpoints to the investigation and modelling of pathways of toxicity and the underlying molecular effects.The U.S. Toxicology in the 21st Century (Tox21 initiative has screened a large library of compounds, including approximately 10K environmental chemicals and drugs, for different mechanisms responsible for eliciting toxic effects, and made the results publicly available. Through the Tox21 Data Challenge, the consortium has established a platform for computational toxicologists to develop and validate their predictive models.Here, we present a fast and successful method for the prediction of different outcomes of the nuclear receptor and stress response pathway screening from the Tox21 Data Challenge 2014. The method is based on the combination of molecular similarity calculations and a naïve Bayes machine learning algorithm and has been implemented as a KNIME pipeline. Molecules are represented as binary vectors consisting of a concatenation of common two-dimensional molecular fingerprint types with topological compound properties. The prediction method has been optimized individually for each modelled target and evaluated in a cross-validation as well as with the independent Tox21 validation set. Our results show that the method can achieve good prediction accuracies and rank among the top algorithms submitted to the prediction challenge, indicating its broad applicability in

  12. Validity of a simple Internet-based outcome-prediction tool in patients with total hip replacement: a pilot study.

    Science.gov (United States)

    Stöckli, Cornel; Theiler, Robert; Sidelnikov, Eduard; Balsiger, Maria; Ferrari, Stephen M; Buchzig, Beatus; Uehlinger, Kurt; Riniker, Christoph; Bischoff-Ferrari, Heike A

    2014-04-01

    We developed a user-friendly Internet-based tool for patients undergoing total hip replacement (THR) due to osteoarthritis to predict their pain and function after surgery. In the first step, the key questions were identified by statistical modelling in a data set of 375 patients undergoing THR. Based on multiple regression, we identified the two most predictive WOMAC questions for pain and the three most predictive WOMAC questions for functional outcome, while controlling for comorbidity, body mass index, age, gender and specific comorbidities relevant to the outcome. In the second step, a pilot study was performed to validate the resulting tool against the full WOMAC questionnaire among 108 patients undergoing THR. The mean difference between observed (WOMAC) and model-predicted value was -1.1 points (95% confidence interval, CI -3.8, 1.5) for pain and -2.5 points (95% CI -5.3, 0.3) for function. The model-predicted value was within 20% of the observed value in 48% of cases for pain and in 57% of cases for function. The tool demonstrated moderate validity, but performed weakly for patients with extreme levels of pain and extreme functional limitations at 3 months post surgery. This may have been partly due to early complications after surgery. However, the outcome-prediction tool may be useful in helping patients to become better informed about the realistic outcome of their THR.

  13. Molecular medicine of fragile X syndrome: based on known molecular mechanisms.

    Science.gov (United States)

    Luo, Shi-Yu; Wu, Ling-Qian; Duan, Ran-Hui

    2016-02-01

    Extensive research on fragile X mental retardation gene knockout mice and mutant Drosophila models has largely expanded our knowledge on mechanism-based treatment of fragile X syndrome (FXS). In light of these findings, several clinical trials are now underway for therapeutic translation to humans. Electronic literature searches were conducted using the PubMed database and ClinicalTrials.gov. The search terms included "fragile X syndrome", "FXS and medication", "FXS and therapeutics" and "FXS and treatment". Based on the publications identified in this search, we reviewed the neuroanatomical abnormalities in FXS patients and the potential pathogenic mechanisms to monitor the progress of FXS research, from basic studies to clinical trials. The pathological mechanisms of FXS were categorized on the basis of neuroanatomy, synaptic structure, synaptic transmission and fragile X mental retardation protein (FMRP) loss of function. The neuroanatomical abnormalities in FXS were described to motivate extensive research into the region-specific pathologies in the brain responsible for FXS behavioural manifestations. Mechanism-directed molecular medicines were classified according to their target pathological mechanisms, and the most recent progress in clinical trials was discussed. Current mechanism-based studies and clinical trials have greatly contributed to the development of FXS pharmacological therapeutics. Research examining the extent to which these treatments provided a rescue effect or FMRP compensation for the developmental impairments in FXS patients may help to improve the efficacy of treatments.

  14. Exploring the efficacy of replacing linear paper-based patient cases in problem-based learning with dynamic Web-based virtual patients: randomized controlled trial.

    Science.gov (United States)

    Poulton, Terry; Ellaway, Rachel H; Round, Jonathan; Jivram, Trupti; Kavia, Sheetal; Hilton, Sean

    2014-11-05

    Problem-based learning (PBL) is well established in medical education and beyond, and continues to be developed and explored. Challenges include how to connect the somewhat abstract nature of classroom-based PBL with clinical practice and how to maintain learner engagement in the process of PBL over time. A study was conducted to investigate the efficacy of decision-PBL (D-PBL), a variant form of PBL that replaces linear PBL cases with virtual patients. These Web-based interactive cases provided learners with a series of patient management pathways. Learners were encouraged to consider and discuss courses of action, take their chosen management pathway, and experience the consequences of their decisions. A Web-based application was essential to allow scenarios to respond dynamically to learners' decisions, to deliver the scenarios to multiple PBL classrooms in the same timeframe, and to record centrally the paths taken by the PBL groups. A randomized controlled trial in crossover design was run involving all learners (N=81) in the second year of the graduate entry stream for the undergraduate medicine program at St George's University of London. Learners were randomized to study groups; half engaged in a D-PBL activity whereas the other half had a traditional linear PBL activity on the same subject material. Groups alternated D-PBL and linear PBL over the semester. The measure was mean cohort performance on specific face-to-face exam questions at the end of the semester. D-PBL groups performed better than linear PBL groups on questions related to D-PBL with the difference being statistically significant for all questions. Differences between the exam performances of the 2 groups were not statistically significant for the questions not related to D-PBL. The effect sizes for D-PBL-related questions were large and positive (>0.6) except for 1 question that showed a medium positive effect size. The effect sizes for questions not related to D-PBL were all small (≤0

  15. Calculating evidence-based renal replacement therapy – Introducing an excel-based calculator to improve prescribing and delivery in renal replacement therapy – A before and after study

    OpenAIRE

    Cottle, Daniel; Mousdale, Stephen; Waqar-Uddin, Haroon; Tully, Redmond; Taylor, Benjamin

    2015-01-01

    Background Transferring the theoretical aspect of continuous renal replacement therapy to the bedside and delivering a given “dose” can be difficult. In research, the “dose” of renal replacement therapy is given as effluent flow rate in ml kg−1 h−1. Unfortunately, most machines require other information when they are initiating therapy, including blood flow rate, pre-blood pump flow rate, dialysate flow rate, etc. This can lead to confusion, resulting in patients receiving inappropriate doses...

  16. Molecular signatures-based prediction of enzyme promiscuity.

    Science.gov (United States)

    Carbonell, Pablo; Faulon, Jean-Loup

    2010-08-15

    Enzyme promiscuity, a property with practical applications in biotechnology and synthetic biology, has been related to the evolvability of enzymes. At the molecular level, several structural mechanisms have been linked to enzyme promiscuity in enzyme families. However, it is at present unclear to what extent these observations can be generalized. Here, we introduce for the first time a method for predicting catalytic and substrate promiscuity using a graph-based representation known as molecular signature. Our method, which has an accuracy of 85% for the non-redundant KEGG database, is also a powerful analytical tool for characterizing structural determinants of protein promiscuity. Namely, we found that signatures with higher contribution to the prediction of promiscuity are uniformly distributed in the protein structure of promiscuous enzymes. In contrast, those signatures that act as promiscuity determinants are significantly depleted around non-promiscuous catalytic sites. In addition, we present the study of the enolase and aminotransferase superfamilies as illustrative examples of characterization of promiscuous enzymes within a superfamily and achievement of enzyme promiscuity by protein reverse engineering. Recognizing the role of enzyme promiscuity in the process of natural evolution of enzymatic function can provide useful hints in the design of directed evolution experiments. We have developed a method with potential applications in the guided discovery and enhancement of latent catalytic capabilities surviving in modern enzymes. http://www.issb.genopole.fr~faulon.

  17. Bases moleculares de alfa-talasemia en la Argentina

    Directory of Open Access Journals (Sweden)

    Karen G Scheps

    2015-04-01

    Full Text Available La α-talasemia, es uno de los desórdenes hereditarios más frecuentes mundialmente. Al presente, el diagnóstico molecular es la única herramienta que permite el diagnóstico certero. El propósito de este trabajo fue caracterizar las bases moleculares de estos síndromes en nuestro medio, y establecer relaciones genotipo-fenotipo. Mediante la complementación de distintas técnicas de biología molecular e hibridación fluorescente in situ (FISH, se logró poner en evidencia la presencia de mutaciones α-talasémicas en 145 de 184 (78.8% pacientes estudiados con perfil hematológico compatible con α-talasemia. Dentro de este grupo, las deleciones correspondieron al defecto genético más frecuente, prevaleciendo la mutación -α3.7 en genotipos heterocigotas y homocigotas. Asimismo, en pacientes con fenotipo α0 las deleciones prevalentes fueron -MED y -CAL/CAMP. Este estudio permitió también describir una deleción de la región sub-telomérica en un paciente con α-talasemia y retraso mental. En el 7.6% de los pacientes caracterizados clínicamente como posibles α-talasémicos (microcitosis con valores de Hb A2 inferiores al 3.5%, se hallaron mutaciones β-talasémicas en estado heterocigota. Se lograron establecer perfiles hematológicos asociados a los genotipos α+ y α0 para pacientes adultos y niños. Esperamos que este trabajo pueda servir como guía para reconocer posibles portadores α-talasémicos. También permite destacar el trabajo en conjunto de médicos hematólogos, el laboratorio (bioquímico y de biología molecular y de los médicos genetistas, con el fin de proporcionar adecuado consejo genético.

  18. Fullerene-based anchoring groups for molecular electronics.

    Science.gov (United States)

    Martin, Christian A; Ding, Dapeng; Sørensen, Jakob Kryger; Bjørnholm, Thomas; van Ruitenbeek, Jan M; van der Zant, Herre S J

    2008-10-08

    We present results on a new fullerene-based anchoring group for molecular electronics. Using lithographic mechanically controllable break junctions in vacuum we have determined the conductance and stability of single-molecule junctions of 1,4-bis(fullero[c]pyrrolidin-1-yl)benzene. The compound can be self-assembled from solution and has a low-bias conductance of 3 x 10(-4) G0. Compared to 1,4-benzenedithiol the fullerene-anchored molecule exhibits a considerably lower conductance spread. In addition, the signature of the new compound in histograms is more significant than that of 1,4-benzenediamine, probably owing to a more stable adsorption motif. Statistical analyses of the breaking of the junctions confirm the stability of the fullerene-gold bond.

  19. Long-Term Weight-Loss Maintenance by a Meal Replacement Based Weight Management Program in Primary Care.

    Science.gov (United States)

    Kruschitz, Renate; Wallner-Liebmann, Sandra; Lothaller, Harald; Luger, Maria; Ludvik, Bernhard

    2017-01-01

    Structured obesity treatment programs at primary care level are becoming increasingly important. However, evidence from current treatment approaches in the long term is lacking. In view of this fact we evaluated a standardized, meal replacement-based weight loss program (myLINE®; AENGUS, Graz, Austria) according to the currently applicable guidelines. Data of overweight and obese individuals (n = 70) who participated at least 36 months in the program were analyzed. Data were collected at baseline (T0) as well as after 1, 3, 6, 12, 24, and 36 (T1-T36) months. Body composition was measured by conventional anthropometry and bioelectrical impedance analysis. Compared to T0, a maximum weight, BMI, fat mass, absolute body cell mass (BCM) reduction and an increase of relative BCM could be seen at T6. Subsequently, the findings reveal a significant reduction of body weight and body fat and a satisfying development of body cell mass during the observation period of 36 months. The evaluated program complies with national and international guidelines for the therapy of obesity in adults and is efficient and meaningful for a long-term therapeutic use in primary care.. © 2017 The Author(s) Published by S. Karger GmbH, Freiburg.

  20. Long-Term Weight-Loss Maintenance by a Meal Replacement Based Weight Management Program in Primary Care

    Directory of Open Access Journals (Sweden)

    Renate Kruschitz

    2017-04-01

    Full Text Available Objective: Structured obesity treatment programs at primary care level are becoming increasingly important. However, evidence from current treatment approaches in the long term is lacking. In view of this fact we evaluated a standardized, meal replacement-based weight loss program (myLINE®; AENGUS, Graz, Austria according to the currently applicable guidelines. Methods: Data of overweight and obese individuals (n = 70 who participated at least 36 months in the program were analyzed. Data were collected at baseline (T0 as well as after 1, 3, 6, 12, 24, and 36 (T1-T36 months. Body composition was measured by conventional anthropometry and bioelectrical impedance analysis. Results: Compared to T0, a maximum weight, BMI, fat mass, absolute body cell mass (BCM reduction and an increase of relative BCM could be seen at T6. Subsequently, the findings reveal a significant reduction of body weight and body fat and a satisfying development of body cell mass during the observation period of 36 months. Conclusion: The evaluated program complies with national and international guidelines for the therapy of obesity in adults and is efficient and meaningful for a long-term therapeutic use in primary care..

  1. An Analysis of Differences in Terms of Professional Interests Based on the Project to Replace IAS 39

    Directory of Open Access Journals (Sweden)

    Cláudia Daniela Ferreira da Mota Carvalho

    2015-08-01

    Full Text Available The professional interests of the various stakeholders groups are often seen as obstacles to full accounting harmonization. Studying different professional interests in the accounting domain is significant for organizations involved in the international accounting harmonization process, insofar as it enables them to identify the main obstacles to face in order to achieve full harmonization. Thus, this article is aimed at analyzing the differences in terms of professional interests by addressing the participation of various stakeholders groups in the process of issuing/modifying standards of the International Accounting Standards Board (IASB. Based on content analysis, we examined the comment letters sent to the IASB in the context of the first part of the first phase of the project to replace the International Accounting Standard (IAS 39, entitled "Financial Instruments - Recognition and Measurement", by the International Financial Reporting Standard (IFRS 9, on its turn entitled "Financial Instruments". Respondents were identified according to the stakeholders group, and, later, the collected data underwent a nonparametric chi-square test. The results of this study indicate there are significant differences between the answers obtained from the various stakeholders groups involved in the process of issuing or reviewing a standard of the IASB, above all made clear between the group of financial preparers and the regulatory and/or standard-setting agencies and the professional associations related to accounting.

  2. Simulating boreal forest carbon dynamics after stand-replacing fire disturbance: insights from a global process-based vegetation model

    Science.gov (United States)

    Yue, C.; Ciais, P.; Luyssaert, S.; Cadule, P.; Harden, J.; Randerson, J.; Bellassen, V.; Wang, T.; Piao, S.L.; Poulter, B.; Viovy, N.

    2013-01-01

    Stand-replacing fires are the dominant fire type in North American boreal forests. They leave a historical legacy of a mosaic landscape of different aged forest cohorts. This forest age dynamics must be included in vegetation models to accurately quantify the role of fire in the historical and current regional forest carbon balance. The present study adapted the global process-based vegetation model ORCHIDEE to simulate the CO2 emissions from boreal forest fire and the subsequent recovery after a stand-replacing fire; the model represents postfire new cohort establishment, forest stand structure and the self-thinning process. Simulation results are evaluated against observations of three clusters of postfire forest chronosequences in Canada and Alaska. The variables evaluated include: fire carbon emissions, CO2 fluxes (gross primary production, total ecosystem respiration and net ecosystem exchange), leaf area index, and biometric measurements (aboveground biomass carbon, forest floor carbon, woody debris carbon, stand individual density, stand basal area, and mean diameter at breast height). When forced by local climate and the atmospheric CO2 history at each chronosequence site, the model simulations generally match the observed CO2 fluxes and carbon stock data well, with model-measurement mean square root of deviation comparable with the measurement accuracy (for CO2 flux ~100 g C m−2 yr−1, for biomass carbon ~1000 g C m−2 and for soil carbon ~2000 g C m−2). We find that the current postfire forest carbon sink at the evaluation sites, as observed by chronosequence methods, is mainly due to a combination of historical CO2 increase and forest succession. Climate change and variability during this period offsets some of these expected carbon gains. The negative impacts of climate were a likely consequence of increasing water stress caused by significant temperature increases that were not matched by concurrent increases in precipitation. Our simulation

  3. Quality of life among elderly patients undergoing transcatheter or surgical aortic valve replacement- a model-based longitudinal data analysis.

    Science.gov (United States)

    Kaier, Klaus; Gutmann, Anja; Baumbach, Hardy; von Zur Mühlen, Constantin; Hehn, Philip; Vach, Werner; Beyersdorf, Friedhelm; Zehender, Manfred; Bode, Christoph; Reinöhl, Jochen

    2016-07-26

    Quality of life (QoL) measurements reported in observational studies are often biased, since patients who failed to improve are more likely to be unable to respond due to death or impairment. In order to observe the development of QoL in patients close to death, we analyzed a set of monthly QoL measurements for a cohort of elderly patients treated for aortic valve stenosis (AS) with special consideration of the effect of distance to death. QoL in 169 elderly patients (age ≥ 75 years), treated either with transcatheter aortic valve replacement (TAVR; n = 92), surgical aortic-valve replacement (n = 70), or drug-based therapy (n = 7), was evaluated using the standardized EQ-5D questionnaire. Over a two-year period, patients were consulted using monthly telephone interviews or outpatient visits, leading to a total of 2463 time points at which QoL values, New York Heart Association (NYHA) Functional Classification and their status of assistance were assessed. Furthermore, post-procedural clinical events and complications were monitored. Linear and ordered logistic regression analyses with random intercept were carried out, taking into account overall trends and distance to death. QoL measures decreased slightly over time, were temporarily impaired at month 1 after the initial episode of hospitalization and decreased substantially at the end of life with a measurable effect starting at the sixth from last follow-up (month) before death. Many clinical complications (bleeding complications, stroke, acute kidney injury) showed an impairment of QoL measurements, but the inclusion of lagged variables demonstrated medium term (three months) QoL impairments for access site bleeding only. All other complications are associated with event-related impairments that decreased dramatically at the second and third follow-up interviews (month) after event. Distance to death shows clear effects on QoL and should be taken into account when analyzing QoL measures in the

  4. Shoulder replacement - discharge

    Science.gov (United States)

    Total shoulder arthroplasty - discharge; Endoprosthetic shoulder replacement - discharge; Partial shoulder replacement - discharge; Partial shoulder arthroplasty - discharge; Replacement - shoulder - discharge; Arthroplasty - shoulder - discharge

  5. Chemically engineered graphene-based 2D organic molecular magnet.

    Science.gov (United States)

    Hong, Jeongmin; Bekyarova, Elena; de Heer, Walt A; Haddon, Robert C; Khizroev, Sakhrat

    2013-11-26

    Carbon-based magnetic materials and structures of mesoscopic dimensions may offer unique opportunities for future nanomagnetoelectronic/spintronic devices. To achieve their potential, carbon nanosystems must have controllable magnetic properties. We demonstrate that nitrophenyl functionalized graphene can act as a room-temperature 2D magnet. We report a comprehensive study of low-temperature magnetotransport, vibrating sample magnetometry (VSM), and superconducting quantum interference (SQUID) measurements before and after radical functionalization. Following nitrophenyl (NP) functionalization, epitaxially grown graphene systems can become organic molecular magnets with ferromagnetic and antiferromagnetic ordering that persists at temperatures above 400 K. The field-dependent, surface magnetoelectric properties were studied using scanning probe microscopy (SPM) techniques. The results indicate that the NP-functionalization orientation and degree of coverage directly affect the magnetic properties of the graphene surface. In addition, graphene-based organic magnetic nanostructures were found to demonstrate a pronounced magneto-optical Kerr effect (MOKE). The results were consistent across different characterization techniques and indicate room-temperature magnetic ordering along preferred graphene orientations in the NP-functionalized samples. Chemically isolated graphene nanoribbons (CINs) were observed along the preferred functionality directions. These results pave the way for future magnetoelectronic/spintronic applications based on promising concepts such as current-induced magnetization switching, magnetoelectricity, half-metallicity, and quantum tunneling of magnetization.

  6. Light-operated machines based on threaded molecular structures.

    Science.gov (United States)

    Credi, Alberto; Silvi, Serena; Venturi, Margherita

    2014-01-01

    Rotaxanes and related species represent the most common implementation of the concept of artificial molecular machines, because the supramolecular nature of the interactions between the components and their interlocked architecture allow a precise control on the position and movement of the molecular units. The use of light to power artificial molecular machines is particularly valuable because it can play the dual role of "writing" and "reading" the system. Moreover, light-driven machines can operate without accumulation of waste products, and photons are the ideal inputs to enable autonomous operation mechanisms. In appropriately designed molecular machines, light can be used to control not only the stability of the system, which affects the relative position of the molecular components but also the kinetics of the mechanical processes, thereby enabling control on the direction of the movements. This step forward is necessary in order to make a leap from molecular machines to molecular motors.

  7. Molecular Diode Studies Based on a Highly Sensitive Molecular Measurement Technique.

    Science.gov (United States)

    Iwane, Madoka; Fujii, Shintaro; Kiguchi, Manabu

    2017-04-26

    In 1974, molecular electronics pioneers Mark Ratner and Arieh Aviram predicted that a single molecule could act as a diode, in which electronic current can be rectified. The electronic rectification property of the diode is one of basic functions of electronic components and since then, the molecular diode has been investigated as a first single-molecule device that would have a practical application. In this review, we first describe the experimental fabrication and electronic characterization techniques of molecular diodes consisting of a small number of molecules or a single molecule. Then, two main mechanisms of the rectification property of the molecular diode are discussed. Finally, representative results for the molecular diode are reviewed and a brief outlook on crucial issues that need to be addressed in future research is discussed.

  8. Bench-to-bedside review: Treating acid–base abnormalities in the intensive care unit – the role of renal replacement therapy

    OpenAIRE

    Naka, Toshio; Bellomo, Rinaldo

    2004-01-01

    Acid–base disorders are common in critically ill patients. Metabolic acid–base disorders are particularly common in patients who require acute renal replacement therapy. In these patients, metabolic acidosis is common and multifactorial in origin. Analysis of acid–base status using the Stewart–Figge methodology shows that these patients have greater acidemia despite the presence of hypoalbuminemic alkalosis. This acidemia is mostly secondary to hyperphosphatemia, hyperlactatemia, and the accu...

  9. Replacing Lectures in Conventional University Courses by Text-Based Flexible Learning Can Be a Rewarding Experience for the Lecturer and Students

    Science.gov (United States)

    Green, John

    2005-01-01

    For nearly two decades, a proportion of lectures in certain modules in conventional undergraduate diploma and degree courses has been replaced by text-based flexible learning. This flexible learning program has satisfied the various quality assurance procedures in place within the university throughout the period of implementation. Evaluation of…

  10. Hip joint replacement

    Science.gov (United States)

    Hip arthroplasty; Total hip replacement; Hip hemiarthroplasty; Arthritis - hip replacement; Osteoarthritis - hip replacement ... your activities. Most of the time, hip joint replacement is done in people age 60 and older. ...

  11. Cell-based quantification of molecular biomarkers in histopathology specimens.

    Science.gov (United States)

    Al-Kofahi, Yousef; Lassoued, Wiem; Grama, Kedar; Nath, Sumit K; Zhu, Jianliang; Oueslati, Ridha; Feldman, Michael; Lee, William M F; Roysam, Badrinath

    2011-07-01

    To investigate the use of a computer-assisted technology for objective, cell-based quantification of molecular biomarkers in specified cell types in histopathology specimens, with the aim of advancing current visual estimation and pixel-level (rather than cell-based) quantification methods. Tissue specimens were multiplex-immunostained to reveal cell structures, cell type markers, and analytes, and imaged with multispectral microscopy. The image data were processed with novel software that automatically delineates and types each cell in the field, measures morphological features, and quantifies analytes in different subcellular compartments of specified cells.The methodology was validated with the use of cell blocks composed of differentially labelled cultured cells mixed in known proportions, and evaluated on human breast carcinoma specimens for quantifying human epidermal growth factor receptor 2, estrogen receptor, progesterone receptor, Ki67, phospho-extracellular signal-related kinase, and phospho-S6. Automated cell-level analyses closely matched human assessments, but, predictably, differed from pixel-level analyses of the same images. Our method reveals the type, distribution, morphology and biomarker state of each cell in the field, and allows multiple biomarkers to be quantified over specified cell types, regardless of their abundance. It is ideal for studying specimens from patients in clinical trials of targeted therapeutic agents, for investigating minority stromal cell subpopulations, and for phenotypic characterization to personalize therapy and prognosis. © 2011 Blackwell Publishing Limited.

  12. Pathological Bases for a Robust Application of Cancer Molecular Classification

    Directory of Open Access Journals (Sweden)

    Salvador J. Diaz-Cano

    2015-04-01

    Full Text Available Any robust classification system depends on its purpose and must refer to accepted standards, its strength relying on predictive values and a careful consideration of known factors that can affect its reliability. In this context, a molecular classification of human cancer must refer to the current gold standard (histological classification and try to improve it with key prognosticators for metastatic potential, staging and grading. Although organ-specific examples have been published based on proteomics, transcriptomics and genomics evaluations, the most popular approach uses gene expression analysis as a direct correlate of cellular differentiation, which represents the key feature of the histological classification. RNA is a labile molecule that varies significantly according with the preservation protocol, its transcription reflect the adaptation of the tumor cells to the microenvironment, it can be passed through mechanisms of intercellular transference of genetic information (exosomes, and it is exposed to epigenetic modifications. More robust classifications should be based on stable molecules, at the genetic level represented by DNA to improve reliability, and its analysis must deal with the concept of intratumoral heterogeneity, which is at the origin of tumor progression and is the byproduct of the selection process during the clonal expansion and progression of neoplasms. The simultaneous analysis of multiple DNA targets and next generation sequencing offer the best practical approach for an analytical genomic classification of tumors.

  13. Magnetic and electronic properties of porphyrin-based molecular nanowires

    Directory of Open Access Journals (Sweden)

    Jia-Jia Zheng

    2016-01-01

    Full Text Available Using spin-polarized density functional theory calculations, we performed theoretical investigations on the electronic and magnetic properties of transition metal embedded porphyrin-based nanowires (TM-PNWs, TM = Cr, Mn, Co, Ni, Cu, and Zn. Our results indicate that Ni-PNW and Zn-PNW are nonmagnetic while the rest species are magnetic, and the magnetic moments in TM-PNWs and their corresponding isolated monomer structures are found to be the same. In addition, the spin coupling in the magnetic nanowires can be ignored leading to their degenerate AFM and FM states. These results can be ascribed to the weak intermetallic interactions because of the relatively large distances between neighbor TM atoms. Among all TM-PNW structures considered here, only Mn-PNW shows a half-metallic property while the others are predicted to be semiconducting. The present work paves a new way of obtaining ferromagnetic porphyrin-based nanowires with TM atoms distributed separately and orderly, which are expected to be good candidates for catalysts, energy storage and molecular spintronics.

  14. Molecular dosimetry based on radiation induced degradation of polyisobutylene

    International Nuclear Information System (INIS)

    Joerkov Thomsen, Kristina

    1999-01-01

    This project investigates the possibility of qualitative measurement of radiation doses through detection of changes in the average molecular weight in the polymer Polyisobutylene (PIB). Changes in molecular weight and molecular weight distribution is detected by Gel Permeation Chromatography (GPC). The aim of the project is to decide whether or not it is possible to determine a quality difference between α-radiation ( 241 Am, 5,5 MeV) and γ-radiation ( 60 Co, 1,25 MeV) in the dose range 0,5 to 10 kGy by irradiation of PIB. Irradiation with 60 Co changes the average number molecular weight M n by 12% per kGy and the average weight molecular weight M w by 23% per kGy. The presence of antioxidant in the irradiated sample inhibits a change in average molecular weight by 5% and 16% for M n and M w respectively. (au)

  15. The influence of malalignment and ageing following sterilisation by gamma irradiation in an inert atmosphere on the wear of ultra-high-molecular-weight polyethylene in patellofemoral replacements.

    Science.gov (United States)

    Maiti, Raman; Cowie, Raelene M; Fisher, John; Jennings, Louise M

    2017-07-01

    Complications of patellofemoral arthroplasty often occur soon after implantation and, as well as other factors, can be due to the design of the implant or its surgical positioning. A number of studies have previously considered the wear of ultra-high-molecular-weight polyethylene patellae following suboptimal implantation; however, studies have primarily been carried out under a limited number of degrees of freedom. The aim of this study was to develop a protocol to assess the wear of patellae under a malaligned condition in a six-axis patellofemoral joint simulator. The malalignment protocol hindered the tracking of the patella centrally in the trochlear groove and imparted a constant 5° external rotation (tilt) on the patella button. Following 3 million cycles of wear simulation, this condition had no influence on the wear of ultra-high-molecular-weight polyethylene patellae aged for 4 years compared to well-positioned non-aged implants (p > 0.05). However, under the malaligned condition, ultra-high-molecular-weight polyethylene patellae aged 8-10 years after unpacking (following sterilisation by gamma irradiation in an inert atmosphere) and worn ultra-high-molecular-weight polyethylene components also aged 4 years after unpacking (following the same sterilisation process) exhibited a high rate of wear. Fatigue failure due to elevated contact stress led to delamination of the ultra-high-molecular-weight polyethylene and in some cases complete failure of the patellae. The results suggest that suboptimal tracking of the patella in the trochlear groove and tilt of the patella button could have a significant effect on the wear of ultra-high-molecular-weight polyethylene and could lead to implant failure.

  16. Toward molecular trait-based ecology through integration of biogeochemical, geographical and metagenomic data

    DEFF Research Database (Denmark)

    Raes, Jeroen; Letunic, Ivica; Yamada, Takuji

    2011-01-01

    provincialism). Molecular functional richness and diversity show a distinct latitudinal gradient peaking at 20° N and correlate with primary production. The latter can also be predicted from the molecular functional composition of an environmental sample. Together, our results show that the functional community...... composition derived from metagenomes is an important quantitative readout for molecular trait-based biogeography and ecology....

  17. Optical materials based on molecular nano/microcrystals and ...

    Indian Academy of Sciences (India)

    Wintec

    tics and attributes, and (iii) extensive application potential. There is ... Molecular scale de- vices of great current interest in areas such as spintronics, electronics and photonics (Kasai et al 1999) can be visu- alized as the logical extension of the molecular nano- ... gestion of the colloid at different temperatures (figure 1).

  18. Molecular clips based on propanediurea : synthesis and physical properties

    NARCIS (Netherlands)

    Jansen, Robertus Johannes

    2002-01-01

    This thesis describes the synthesis and physical properties of a series of molecular clips derived from the concave molecule propanediurea. These molecular clips are cavity-containing receptors that can bind a variety of aromatic guests. This binding is a result of hydrogen bonding and pi-pi

  19. Optical materials based on molecular nano/microcrystals and ...

    Indian Academy of Sciences (India)

    Wintec

    Abstract. Methodologies that we developed recently for the fabrication of molecular crystals with size varia- tion in the nano to micro regime and polyelectrolyte templated mono and multilayer Langmuir–Blodgett films, are reviewed. The electronic absorption and strong fluorescence in the molecular nano/microcrystals are.

  20. Prevention of postoperative venous thrombosis: a randomized trial comparing unfractionated heparin with low molecular weight heparin in patients undergoing total hip replacement.

    Science.gov (United States)

    Planes, A; Vochelle, N; Mazas, F; Mansat, C; Zucman, J; Landais, A; Pascariello, J C; Weill, D; Butel, J

    1988-12-22

    A double blind randomized trial comparing subcutaneous enoxaparin (40 mg once daily) with standard unfractionated calcium heparin administered at a dose of 5,000 units every 8 hours in patients undergoing elective hip replacement has been performed. Treatment regimens began 12 hours preoperatively with enoxaparin, 2 hours preoperatively with standard unfractionated calcium heparin, and were continued for 15 days or until discharge. Venography was performed in all patients. Two hundred thirty-seven patients were included in the study: 113 received unfractionated heparin and 124 received enoxaparin. The incidence of proximal deep vein thrombosis was reduced from 18.5% in the unfractionated heparin group to 7.5% in the enoxaparin group (p = 0.014), and the incidence of total deep vein thrombosis was similarly reduced from 25% to 12.5% (p = 0.03). There were two major bleeding episodes and one minor bleed in the enoxaparin group compared to two minor bleeds in the unfractionated heparin group. Patients who received enoxaparin required fewer red blood cell transfusions and had a significantly higher hemoglobin on postoperative days 3 and 4. Thus prophylaxis with enoxaparin, 40 mg once daily, is simple, safe and more effective than standard low dose unfractionated heparin in preventing deep vein thrombosis in patients undergoing elective hip replacement.

  1. Maximizing genetic differentiation in core collections by PCA-based clustering of molecular marker data.

    Science.gov (United States)

    van Heerwaarden, Joost; Odong, T L; van Eeuwijk, F A

    2013-03-01

    Developing genetically diverse core sets is key to the effective management and use of crop genetic resources. Core selection increasingly uses molecular marker-based dissimilarity and clustering methods, under the implicit assumption that markers and genes of interest are genetically correlated. In practice, low marker densities mean that genome-wide correlations are mainly caused by genetic differentiation, rather than by physical linkage. Although of central concern, genetic differentiation per se is not specifically targeted by most commonly employed dissimilarity and clustering methods. Principal component analysis (PCA) on genotypic data is known to effectively describe the inter-locus correlations caused by differentiation, but to date there has been no evaluation of its application to core selection. Here, we explore PCA-based clustering of marker data as a basis for core selection, with the aim of demonstrating its use in capturing genetic differentiation in the data. Using simulated datasets, we show that replacing full-rank genotypic data by the subset of genetically significant PCs leads to better description of differentiation and improves assignment of genotypes to their population of origin. We test the effectiveness of differentiation as a criterion for the formation of core sets by applying a simple new PCA-based core selection method to simulated and actual data and comparing its performance to one of the best existing selection algorithms. We find that although gains in genetic diversity are generally modest, PCA-based core selection is equally effective at maximizing diversity at non-marker loci, while providing better representation of genetically differentiated groups.

  2. Molecular microenvironments: Solvent interactions with nucleic acid bases and ions

    Science.gov (United States)

    Macelroy, R. D.; Pohorille, A.

    1986-01-01

    The possibility of reconstructing plausible sequences of events in prebiotic molecular evolution is limited by the lack of fossil remains. However, with hindsight, one goal of molecular evolution was obvious: the development of molecular systems that became constituents of living systems. By understanding the interactions among molecules that are likely to have been present in the prebiotic environment, and that could have served as components in protobiotic molecular systems, plausible evolutionary sequences can be suggested. When stable aggregations of molecules form, a net decrease in free energy is observed in the system. Such changes occur when solvent molecules interact among themselves, as well as when they interact with organic species. A significant decrease in free energy, in systems of solvent and organic molecules, is due to entropy changes in the solvent. Entropy-driven interactioins played a major role in the organization of prebiotic systems, and understanding the energetics of them is essential to understanding molecular evolution.

  3. AVE5026, a new hemisynthetic ultra-low-molecular-weight heparin for the prevention of venous thromboembolism in patients after total knee replacement surgery

    DEFF Research Database (Denmark)

    Lassen, Michael Rud; Dahl, O E; Mismetti, P

    2009-01-01

    BACKGROUND: AVE5026 is a new hemisynthetic ultra-low-molecular-weight heparin, with a novel anti-thrombotic profile resulting from high anti-factor (F)Xa activity and residual anti-FIIa activity. AVE5026 is in clinical development for venous thromboembolism (VTE) prevention, a frequent complication...

  4. UPAR targeted molecular imaging of cancers with small molecule-based probes.

    Science.gov (United States)

    Ding, Feng; Chen, Seng; Zhang, Wanshu; Tu, Yufeng; Sun, Yao

    2017-10-15

    Molecular imaging can allow the non-invasive characterization and measurement of biological and biochemical processes at the molecular and cellular levels in living subjects. The imaging of specific molecular targets that are associated with cancers could allow for the earlier diagnosis and better treatment of diseases. Small molecule-based probes play prominent roles in biomedical research and have high clinical translation ability. Here, with an emphasis on small molecule-based probes, we review some recent developments in biomarkers, imaging techniques and multimodal imaging in molecular imaging and highlight the successful applications for molecular imaging of cancers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Symbol Synchronization for Diffusion-Based Molecular Communications.

    Science.gov (United States)

    Jamali, Vahid; Ahmadzadeh, Arman; Schober, Robert

    2017-12-01

    Symbol synchronization refers to the estimation of the start of a symbol interval and is needed for reliable detection. In this paper, we develop several symbol synchronization schemes for molecular communication (MC) systems where we consider some practical challenges, which have not been addressed in the literature yet. In particular, we take into account that in MC systems, the transmitter may not be equipped with an internal clock and may not be able to emit molecules with a fixed release frequency. Such restrictions hold for practical nanotransmitters, e.g., modified cells, where the lengths of the symbol intervals may vary due to the inherent randomness in the availability of food and energy for molecule generation, the process for molecule production, and the release process. To address this issue, we develop two synchronization-detection frameworks which both employ two types of molecule. In the first framework, one type of molecule is used for symbol synchronization and the other one is used for data detection, whereas in the second framework, both types of molecule are used for joint symbol synchronization and data detection. For both frameworks, we first derive the optimal maximum likelihood (ML) symbol synchronization schemes as performance upper bounds. Since ML synchronization entails high complexity, for each framework, we also propose three low-complexity suboptimal schemes, namely a linear filter-based scheme, a peak observation-based scheme, and a threshold-trigger scheme, which are suitable for MC systems with limited computational capabilities. Furthermore, we study the relative complexity and the constraints associated with the proposed schemes and the impact of the insertion and deletion errors that arise due to imperfect synchronization. Our simulation results reveal the effectiveness of the proposed synchronization schemes and suggest that the end-to-end performance of MC systems significantly depends on the accuracy of the symbol

  6. Inpatient treatment and care arrangements to replace or avoid it - Searching for an evidence-based balance

    NARCIS (Netherlands)

    Kluiter, H

    In several countries, it seems to be policy to strive for a mental health system dominated by variants of community care replacing hospital care and culminating in closure of hospitals. Scientific evidence shows that no form of community care for the seriously mentally ill can do without the

  7. Electrodeposition of Pd based binary catalysts on Carbon paper via surface limited redox-replacement reaction for oxygen reduction reaction

    CSIR Research Space (South Africa)

    Modibedi, RM

    2014-05-01

    Full Text Available attention as it is more abundant and also cheaper than Pt. In this presentation, Electrochemical Atomic Layer Deposition (ECALD) was used in the preparation of binary ORR catalysts. The binary nanoclusters were synthesised via surface-limited redox-replacement...

  8. Evidence-based recommendations for monitoring bone disease and the response to enzyme replacement therapy in Gaucher patients

    NARCIS (Netherlands)

    vom Dahl, Stephan; Poll, Ludger; Di Rocco, Maja; Ciana, Giovanni; Denes, Carmencita; Mariani, Giuliano; Maas, Mario

    2006-01-01

    Background: Bone disease is a serious complication of Gaucher disease. Untreated, it can result in pain, permanent bone damage and disability. Enzyme replacement therapy reverses many of the clinical signs of Gaucher bone disease but early assessment and treatment, and regular monitoring, are

  9. Meal replacement based on Human Ration modulates metabolic risk factors during body weight loss: a randomized controlled trial.

    Science.gov (United States)

    Alves, Natalia Elizabeth Galdino; Enes, Bárbara Nery; Martino, Hércia Stampini Duarte; Alfenas, Rita de Cássia Gonçalves; Ribeiro, Sônia Machado Rocha

    2014-04-01

    A meal replacement may be an effective strategy in the management of obesity to increase antioxidant intake, attenuating oxidative stress and inflammation. In the present study, we investigated the efficacy of a new nutritional supplement to reduce metabolic risk parameters in obese women. In a randomized controlled crossover study (2 × 2), 22 women (percentage body fat 40.52 ± 3.75%; body mass index-BMI 28.72 ± 2.87 kg/m²; 35.04 ± 5.6 years old) were allocated into two treatments: hypocaloric diet and drink containing "Human Ration" (HR) consumption (CRHR), and hypocaloric diet and control drink consumption (CR). The study consisted of 2 periods of 5 weeks with 1 week of washout in two orders (CR → CRHR and CRHR → CR). Caloric restriction was 15%, based on estimated energy requirement. Anthropometric, clinical and metabolic risk parameters were assessed at baseline and at the end of each period. Some metabolic risk factors were favorably modulated in both interventions: reduction in body weight (CR -0.74 ± 1.27 kg; p = 0.01; CRHR -0.77 ± 1.3 kg; p = 0.02), body mass index (BMI) (CR -0.27 ± 0.51 kg/m²; p = 0.02; CRHR -0.30 ± 0.52 kg/m²; p = 0.01) and HOMA-IR (CR -0.35 ± 0.82; p = 0.02, CRHR -0.41 ± 0.83; p = 0.03). However, CRHR reduced waist circumference (-2.54 ± 2.74 cm; p < 0.01) and gynoid fat (-0.264 ± 0.28 g; p < 0.01), and increased HDL-c levels (0.08 ± 0.15 mmol/l; p = 0.04). Associated with hypocaloric diet, the intake of a nutritional supplement rich in phytochemicals as a breakfast substitute for 5 weeks had no additional effect on weight reduction than caloric restriction alone, but increased central lipolysis and improved the lipoprotein profile.

  10. Liquid hydrocarbon fuels containing high molecular weight Mannich bases

    Energy Technology Data Exchange (ETDEWEB)

    Udelhofen, J.H.; Watson, R.W.

    1980-11-04

    Reaction products obtained from the Mannich condensation of high molecular weight alkyl-substituted hydroxy aromatic compounds, amines and aldehydes provide improved detergency in liquid hydrocarbon fuels. Optionally, a non-volatile hydrocarbon carrier fluid may be included.

  11. Optical fiber-based photomechanical molecular delivery system

    Science.gov (United States)

    Nakano, Koki; Sato, Shunichi; Kawauchi, Satoko; Ashida, Hiroshi; Nishidate, Izumi

    2014-02-01

    Molecular delivery based on nanosecond pulsed laser-induced photomechanical waves (PMWs) enables endoscopic application by using an optical fiber for laser transmission. In our previous fiber system, a laser target, which was a black natural rubber film as a laser absorbing material covered with an optically transparent polyethylene terephthalate disk to confine the laser-induced plasma, was attached to the output end of a 1 mm core diameter quartz fiber. There were two problems in that system: 1) the outer diameter was large (~2.7 mm) and 2) available peak pressure rapidly decreased with increasing pulse number. In this study, we developed a new fiber delivery system to overcome these problems. As a laser absorbing material, we used a cap-type silicone rubber containing carbon black, into which the fiber output end can simply be inserted. The fiber end surface works to confine the laser-induced plasma. The outer diameter of the fiber system was reduced to ~1.4 mm. At an output laser fluence of 1.2 J/cm2, peak pressure of the first PMW pulse exceeded ~40 MPa. With successive 10 laser pulses, decreasing rate of the peak pressure was 22%, which was considerably lower than that with the previous fiber system (82%), enabling generation of at least successive 30 pulses of PMW with the same cap-type target. With this fiber system, we attempted transfer of plasmid DNA encoding EGFP (enhanced green fluorescence protein) to the rat skin as a test tissue in vivo, showing site-selective efficient gene expression.

  12. Congenital neutropenia: diagnosis, molecular bases and patient management

    Directory of Open Access Journals (Sweden)

    Chantelot Christine

    2011-05-01

    Full Text Available Abstract The term congenital neutropenia encompasses a family of neutropenic disorders, both permanent and intermittent, severe ( When neutropenia is detected, an attempt should be made to establish the etiology, distinguishing between acquired forms (the most frequent, including post viral neutropenia and auto immune neutropenia and congenital forms that may either be isolated or part of a complex genetic disease. Except for ethnic neutropenia, which is a frequent but mild congenital form, probably with polygenic inheritance, all other forms of congenital neutropenia are extremely rare and have monogenic inheritance, which may be X-linked or autosomal, recessive or dominant. About half the forms of congenital neutropenia with no extra-hematopoetic manifestations and normal adaptive immunity are due to neutrophil elastase (ELANE mutations. Some patients have severe permanent neutropenia and frequent infections early in life, while others have mild intermittent neutropenia. Congenital neutropenia may also be associated with a wide range of organ dysfunctions, as for example in Shwachman-Diamond syndrome (associated with pancreatic insufficiency and glycogen storage disease type Ib (associated with a glycogen storage syndrome. So far, the molecular bases of 12 neutropenic disorders have been identified. Treatment of severe chronic neutropenia should focus on prevention of infections. It includes antimicrobial prophylaxis, generally with trimethoprim-sulfamethoxazole, and also granulocyte-colony-stimulating factor (G-CSF. G-CSF has considerably improved these patients' outlook. It is usually well tolerated, but potential adverse effects include thrombocytopenia, glomerulonephritis, vasculitis and osteoporosis. Long-term treatment with G-CSF, especially at high doses, augments the spontaneous risk of leukemia in patients with congenital neutropenia.

  13. Prioritizing equipment for replacement.

    Science.gov (United States)

    Capuano, Mike

    2010-01-01

    It is suggested that clinical engineers take the lead in formulating evaluation processes to recommend equipment replacement. Their skill, knowledge, and experience, combined with access to equipment databases, make them a logical choice. Based on ideas from Fennigkoh's scheme, elements such as age, vendor support, accumulated maintenance cost, and function/risk were used.6 Other more subjective criteria such as cost benefits and efficacy of newer technology were not used. The element of downtime was also omitted due to the data element not being available. The resulting Periop Master Equipment List and its rationale was presented to the Perioperative Services Program Council. They deemed the criteria to be robust and provided overwhelming acceptance of the list. It was quickly put to use to estimate required capital funding, justify items already thought to need replacement, and identify high-priority ranked items for replacement. Incorporating prioritization criteria into an existing equipment database would be ideal. Some commercially available systems do have the basic elements of this. Maintaining replacement data can be labor-intensive regardless of the method used. There is usually little time to perform the tasks necessary for prioritizing equipment. However, where appropriate, a clinical engineering department might be able to conduct such an exercise as shown in the following case study.

  14. Investigating the rheological, microstructural and textural properties of chocolates sweetened with palm sap-based sugar by partial replacement

    OpenAIRE

    Saputro, Arifin Dwi; Van de Walle, Davy; Kadivar, Sheida; Sintang, Mohd Dona Bin; Van Der Meeren, Paul; Dewettinck, Koen

    2017-01-01

    Palm sugar, a natural alternative sweetener which can be made from the nectar of several species of palm tree flowers, recently gains more interest. Due to its physicochemical characteristics, utilisation of palm sugar as chocolate sweetener results in different quality attributes of chocolate. In this work, a thorough investigation about the influence of palm sugar on the rheological, microstructural and textural characteristics of chocolate was carried out through partial replacement of suc...

  15. Molecular materials and devices: developing new functional systems based on the coordination chemistry approach

    Directory of Open Access Journals (Sweden)

    Toma Henrique E.

    2003-01-01

    Full Text Available At the onset of the nanotechnology age, molecular designing of materials and single molecule studies are opening wide possibilities of using molecular systems in electronic and photonic devices, as well as in technological applications based on molecular switching or molecular recognition. In this sense, inorganic chemists are privileged by the possibility of using the basic strategies of coordination chemistry to build up functional supramolecular materials, conveying the remarkable chemical properties of the metal centers and the characteristics of the ancillary ligands. Coordination chemistry also provides effective self-assembly strategies based on specific metal-ligand affinity and stereochemistry. Several molecular based materials, derived from inorganic and metal-organic compounds are focused on this article, with emphasis on new supramolecular porphyrins and porphyrazines, metal-clusters and metal-polyimine complexes. Such systems are also discussed in terms of their applications in catalysis, sensors and molecular devices.

  16. Nanohashtag structures based on carbon nanotubes and molecular linkers

    Science.gov (United States)

    Frye, Connor W.; Rybolt, Thomas R.

    2018-03-01

    Molecular mechanics was used to study the noncovalent interactions between single-walled carbon nanotubes and molecular linkers. Groups of nanotubes have the tendency to form tight, parallel bundles (||||). Molecular linkers were introduced into our models to stabilize nanostructures with carbon nanotubes held in perpendicular orientations. Molecular mechanics makes it possible to estimate the strength of noncovalent interactions holding these structures together and to calculate the overall binding energy of the structures. A set of linkers were designed and built around a 1,3,5,7-cyclooctatetraene tether with two corannulene containing pincers that extend in opposite directions from the central cyclooctatetraene portion. Each pincer consists of a pairs of "arms." These molecular linkers were modified so that the "hand" portions of each pair of "arms" could close together to grab and hold two carbon nanotubes in a perpendicular arrangement. To illustrate the possibility of more complicated and open perpendicular CNTs structures, our primary goal was to create a model of a nanohashtag (#) CNT conformation that is more stable than any parallel CNT arrangements with bound linker molecules forming clumps of CNTs and linkers in non-hashtag arrangements. This goal was achieved using a molecular linker (C280H96) that utilizes van der Waals interactions to two perpendicular oriented CNTs. Hydrogen bonding was then added between linker molecules to augment the stability of the hashtag structure. In the hashtag structure with hydrogen bonding, four (5,5) CNTs of length 4.46 nm (18 rings) and four linkers (C276H92N8O8) stabilized the hashtag so that the average binding energy per pincer was 118 kcal/mol.

  17. Cost effectiveness of transcatheter aortic valve replacement compared to medical management in inoperable patients with severe aortic stenosis: Canadian analysis based on the PARTNER Trial Cohort B findings.

    Science.gov (United States)

    Hancock-Howard, Rebecca L; Feindel, Christopher M; Rodes-Cabau, Josep; Webb, John G; Thompson, Ann K; Banz, Kurt

    2013-01-01

    The only effective treatment for severe aortic stenosis (AS) is valve replacement. However, many patients with co-existing conditions are ineligible for surgical valve replacement, historically leaving medical management (MM) as the only option which has a poor prognosis. Transcatheter Aortic Valve Replacement (TAVR) is a less invasive replacement method. The objective was to estimate cost-effectiveness of TAVR via transfemoral access vs MM in surgically inoperable patients with severe AS from the Canadian public healthcare system perspective. A cost-effectiveness analysis of TAVR vs MM was conducted using a deterministic decision analytic model over a 3-year time horizon. The PARTNER randomized controlled trial results were used to estimate survival, utilities, and some resource utilization. Costs included the valve replacement procedure, complications, hospitalization, outpatient visits/tests, and home/nursing care. Resources were valued (2009 Canadian dollars) using costs from the Ontario Case Costing Initiative (OCCI), Ontario Ministry of Health and Long-Term Care and Ontario Drug Benefits Formulary, or were estimated using relative costs from a French economic evaluation or clinical experts. Costs and outcomes were discounted 5% annually. The effect of uncertainty in model parameters was explored in deterministic and probabilistic sensitivity analysis. The incremental cost-effectiveness ratio (ICER) was $32,170 per quality-adjusted life year (QALY) gained for TAVR vs MM. When the time horizon was shortened to 24 and 12 months, the ICER increased to $52,848 and $157,429, respectively. All other sensitivity analysis returned an ICER of less than $50,000/QALY gained. A limitation was lack of availability of Canadian-specific resource and cost data for all resources, leaving one to rely on clinical experts and data from France to inform certain parameters. Based on the results of this analysis, it can be concluded that TAVR is cost-effective compared to MM for the

  18. Pelvic irradiation does not increase the risk of hip replacement in patients with gynecological cancer. A cohort study based on 8,507 patients.

    Science.gov (United States)

    Dybvik, Eva; Furnes, Ove; Fosså, Sophie D; Trovik, Clement; Lie, Stein Atle

    2014-12-01

    Long-term survivors of cancer can develop adverse effects of the treatment. 60% of cancer patients survive for at least 5 years after diagnosis. Pelvic irradiation can cause bone damage in these long-term survivors, with increased risk of fracture and degeneration of the hip. Analyses were based on linkage between the Cancer Registry of Norway (CRN) and the Norwegian Arthroplasty Register (NAR). All women who had been exposed to radiation for curative radiotherapy of gynecological cancer (40-60 Gy for at least 28 days) were identified in the CRN. Radiotherapy had been given between 1998 and 2006 and only patients who were irradiated within 6 months of diagnosis were included. The control group contained women with breast cancer who had also undergone radiotherapy, but not to the pelvic area. Fine and Gray competing-risk analysis was used to calculate subhazard-rate ratios (subHRRs) and cumulative incidence functions (CIFs) for the risk of having a prosthesis accounting for differences in mortality. Of 962 eligible patients with gynecological cancer, 26 (3%) had received a total hip replacement. In the control group without exposure, 253 (3%) of 7,545 patients with breast cancer had undergone total hip replacement. The 8-year CIF for receiving a total hip replacement was 2.7% (95% CI: 2.6-2.8) for gynecological cancer patients and 3.0% (95% CI: 2.95-3.03) for breast cancer patients; subHRR was 0.80 (95% CI: 0.53-1.22; p=0.3). In both groups, the most common reason for hip replacement was idiopathic osteoarthritis. We did not find any statistically significantly higher risk of undergoing total hip replacement in patients with gynecological cancer who had had pelvic radiotherapy than in women with breast cancer who had not had pelvic radiotherapy.

  19. Nicotine replacement therapy

    Science.gov (United States)

    Smoking cessation - nicotine replacement; Tobacco - nicotine replacement therapy ... Before you start using a nicotine replacement product, here are some things to know: The more cigarettes you smoke, the higher the dose you may need to ...

  20. Hip Replacement Surgery

    Science.gov (United States)

    ... Initiative Breadcrumb Home Health Topics English Español Hip Replacement Surgery Basics In-Depth Download Download EPUB Download ... What is it? Points To Remember About Hip Replacement Surgery Hip replacement surgery removes damaged or diseased ...

  1. Valve Repair or Replacement

    Science.gov (United States)

    ... Replacement Menu Topics Topics FAQs Valve Repair or Replacement Heart valves play a key role in this ... leaflets with a tissue patch. What is valve replacement? Severe valve damage means the valve must be ...

  2. Transcatheter aortic valve replacement

    Science.gov (United States)

    ... gov/ency/article/007684.htm Transcatheter aortic valve replacement To use the sharing features on this page, please enable JavaScript. Transcatheter aortic valve replacement (TAVR) is surgery to replace the aortic valve. ...

  3. Knee joint replacement - discharge

    Science.gov (United States)

    ... Knee replacement - total - discharge; Tricompartmental knee replacement - discharge; Osteoarthritis - knee replacement discharge ... such as downhill skiing or contact sports like football and soccer. But, you should be able to ...

  4. Molecular beam detector on the MX7304 mass spectrometer base

    International Nuclear Information System (INIS)

    Akimov, V.M.; Rusin, L.Yu.; Tsyganov, F.A.

    1991-01-01

    A modified monitor for the MKh-7304 mass spectrometer installed in one of differentially evacuated chambers of the time-of-flight spectrometer. The limit vacuum under operational conditions is 10 -8 torr. The results of testing the molecular beams when recording time-of-flight spectra of Ar, Xe, N 2 are given. It is revealed that the vacuum system time conctant decrease as compared with the system with standard monitor gives an opportunity to register reliability the time-of-flight spectra of molecular beams

  5. Low-molecular-weight carbohydrate Pentaisomaltose may replace dimethyl sulfoxide as a safer cryoprotectant for cryopreservation of peripheral blood stem cells

    DEFF Research Database (Denmark)

    Svalgaard, Jesper Dyrendom; Haastrup, Eva Kannik; Reckzeh, Kristian

    2016-01-01

    -related side effects, there is an increasing demand for DMSO-free alternatives. We therefore investigated whether Pentaisomaltose (PIM), a low-molecular-weight carbohydrate (1 kDa), can be used for cryopreservation of peripheral blood stem cells, more specifically hematopoietic progenitor cell apheresis (HPC......(A)) product. STUDY DESIGN AND METHODS: We cryopreserved patient or donor HPC(A) products using 10% DMSO or 16% PIM and quantified the recovery of CD34+ cells and CD34+ subpopulations by multicolor flow cytometry. In addition, we compared the frequency of HPCs after DMSO and PIM cryopreservation using...... and therefore may have the potential to be used for cryopreservation of peripheral blood stem cells....

  6. Full Length Research Paper LTR-retrotransposons-based molecular ...

    African Journals Online (AJOL)

    LTR-retrotransposons possess unique properties that make them appropriate for investigating relationships between closely related species and populations. The aim of the current study was to employ Ty1-copia group retrotransposons as molecular markers in cultivated Egyptian cottons, G. barbadense L. Restriction site ...

  7. Laser-based molecular spectroscopy for chemical analysis: laser fundamentals.

    NARCIS (Netherlands)

    Moore, D.S.; Vo-Dinh, T.; Velthorst, N.H.; Schrader, B.

    1996-01-01

    This report is 15th in a series on Spectrochemical Methods of Analysis issued by IUPAC Commission V.4. It is concerned with the fundamental properties of lasers as used in analytical molecular spectroscopy in the optical wavelength region. The present report has five main sections: Introduction to

  8. Molecular characterization of Cymbidium kanran cultivars based on ...

    African Journals Online (AJOL)

    Fifty-four Cymbidium kanran cultivars from China, Japan and Korea were examined and analyzed by using the successive screening of 3'-end extended random primer amplified polymorphic DNA (ERAPD) markers to determine their molecular diversity and relationships. In ERAPD analyses, the strandspecific DNA ...

  9. Molecular phylogenetic implications in Brassica napus based on ...

    Indian Academy of Sciences (India)

    Brassica napus L. (canola, rapeseed) is one of the most important oil crops in many countries (Abdelmigid 2012;. Fayyaz et al. 2014), and thought to have originated from a cross where the maternal donor was closely related to two diploid species, B. oleracea (CC, 2n = 18) and B. rapa (AA, 2n = 20). Here, molecular ...

  10. Molecular-based rapid inventories of sympatric diversity: A ...

    Indian Academy of Sciences (India)

    2012-10-15

    Oct 15, 2012 ... Molecular markers offer a universal source of data for quantifying biodiversity. DNA barcoding uses a standardized genetic marker and a curated reference database to identify known species and to reveal cryptic diversity within well- sampled clades. Rapid biological inventories, e.g. rapid assessment ...

  11. LTR-retrotransposons-based molecular markers in cultivated ...

    African Journals Online (AJOL)

    GRACE

    2006-07-03

    Jul 3, 2006 ... LTR-retrotransposons represent a standard component of the Gossypium Genome (Zaki and Abdel Ghany,. 2003). The analysis of the molecular existence and distribution of ancient and active LTR-retrotransposons, therefore, provides a comprehensive evaluation of the evolutionary history of Gossypium.

  12. Molecular characterization of Cymbidium kanran cultivars based on ...

    African Journals Online (AJOL)

    TUOYO

    2010-08-09

    Aug 9, 2010 ... Fifty-four Cymbidium kanran cultivars from China, Japan and Korea were examined and analyzed by using the successive screening of 3′-end extended random primer amplified polymorphic DNA (ERAPD) markers to determine their molecular diversity and relationships. In ERAPD analyses, the strand-.

  13. Molecular filter-based diagnostics in high speed flows

    Science.gov (United States)

    Elliott, Gregory S.; Samimy, MO; Arnette, Stephen A.

    1993-01-01

    The use of iodine molecular filters in nonintrusive planar velocimetry methods is examined. Detailed absorption profiles are obtained to highlight the effects that determine the profile shape. It is shown that pressure broadening induced by the presence of a nonabsorbing vapor can be utilized to significantly change the slopes bounding the absorbing region while remaining in the optically-thick regime.

  14. Effects of replacing extracted soybean meal with rapeseed cake in corn grass silage-based diet for dairy cows.

    Science.gov (United States)

    Rutkowska, Jarosława; Białek, Małgorzata; Bagnicka, Emilia; Jarczak, Justyna; Tambor, Krzysztof; Strzałkowska, Nina; Jóźwik, Artur; Krzyżewski, Józef; Adamska, Agata; Rutkowska, Ewa

    2015-05-01

    The aim of the study was to assess the effects of partial replacement of soybean meal with a protein-equivalent amount of rapeseed cake in the diet on milking parameters and fatty acid (FA) composition of milk in dairy cows. Two groups of Holstein-Friesian cows, 8 each, consisting of randomised blocks were studied: a control group (C) was given a traditional high-protein supplement (extracted soybean meal) and the experimental group (E), had part of extracted soybean meal replaced with rapeseed cake. Dry matter intake and milk yield in both groups were not affected by the diet but milk fat percentage and yield were decreased in both groups. Rapeseed cake had no effect on milk acidity or on protein (including casein) and lactose contents. A lower concentration of urea in milk in E group indicated a proper ratio of protein to energy in the fodder. Health condition of mammary gland and indicators of metabolic profile were not affected by rapeseed cake supplementation. In E group, the share of atherogenic saturated fatty acids (FA) was reduced after 11 weeks: palmitic, by 26% and myristic, by 22%; moreover, as compared with control cows, the content of monounsaturated FA in milk increased by 44% after 3 weeks and by 68% after 11 weeks, t-18:1 and c-9 t-11 isomer of CLA increased about 2.5-fold after 11 weeks. In E group, the atherogenic index (AI) was significantly (P < 0.001) lower than in C (by 54% on average) and the decrease with time was considerable (by 29%, P < 0.001). Contents of odd- and branched- chain FA in milk were not significantly affected thus reflecting proper rumen function. Partial replacement of soybean meal with rapeseed cake in the diet of cows may improve both milking indices and FA profile of milk.

  15. Effects of an Ad Libitum Consumed Low-Fat Plant-Based Diet Supplemented with Plant-Based Meal Replacements on Body Composition Indices

    Directory of Open Access Journals (Sweden)

    Boštjan Jakše

    2017-01-01

    Full Text Available Objective. To document the effect of a diet free from animal-sourced nutrients on body composition indices. Methods. This was a nonrandomized interventional (n=241-control (n=84 trial with a 10-week, low-fat, plant-based diet supplemented with two daily meal replacements. The meals were allowed to be eaten to full satiety without prespecified calorie restrictions. Control subjects received weekly lectures on the rationale and expected benefits of plant-based nutrition. Body composition indices were measured with bioimpedance analysis. Results. Relative to controls, in cases, postintervention body fat percentage was reduced by 4.3 (95% CI 4.1–4.6% points (a relative decrement of −13.4%, visceral fat by 1.6 (95% CI 1.5–1.7 fat cross-sectional surface units, and weight by 5.6 kg (95% CI 5.2–6, while muscle mass was reduced by 0.3 kg (95% CI 0.06–0.5 with a relative increase of muscle mass percentage of 4.2 (3.9–4.4% points. Analysis of covariance showed significantly larger adjusted fat reductions in cases compared to controls. Late follow-up revealed further weight loss in 60% of cases and no significant change in controls. Conclusions. Low-fat, plant-based diet in free-living nonresidential conditions eaten ad libitum enables significant and meaningful body fat reductions with relative preservation of muscle mass. This trial is registered with NCT02906072, ClinicalTrials.gov.

  16. Use of a GIS-based hybrid artificial neural network to prioritize the order of pipe replacement in a water distribution network.

    Science.gov (United States)

    Ho, Cheng-I; Lin, Min-Der; Lo, Shang-Lien

    2010-07-01

    A methodology based on the integration of a seismic-based artificial neural network (ANN) model and a geographic information system (GIS) to assess water leakage and to prioritize pipeline replacement is developed in this work. Qualified pipeline break-event data derived from the Taiwan Water Corporation Pipeline Leakage Repair Management System were analyzed. "Pipe diameter," "pipe material," and "the number of magnitude-3( + ) earthquakes" were employed as the input factors of ANN, while "the number of monthly breaks" was used for the prediction output. This study is the first attempt to manipulate earthquake data in the break-event ANN prediction model. Spatial distribution of the pipeline break-event data was analyzed and visualized by GIS. Through this, the users can swiftly figure out the hotspots of the leakage areas. A northeastern township in Taiwan, frequently affected by earthquakes, is chosen as the case study. Compared to the traditional processes for determining the priorities of pipeline replacement, the methodology developed is more effective and efficient. Likewise, the methodology can overcome the difficulty of prioritizing pipeline replacement even in situations where the break-event records are unavailable.

  17. Molecular evaluations of thirty one clones of poplar based on RAPD and SSR molecular markers

    Directory of Open Access Journals (Sweden)

    Singh M.K.

    2014-01-01

    Full Text Available Poplar is an important tree species valued all over the world for its wood importance. Despite limited knowledge of the levels of genetic diversity and relatedness, their cultivation as a source of plywood is widespread. In order to facilitate reasoned scientific decisions on its management and conservation and prepare for selective breeding programme, genetic analysis of 31 genotypes was performed using RAPD and SSR molecular markers. Twenty six RAPD primers and 14 SSR primers amplified a total of 236 and 85 scoreable bands of which 86.44% and 86.02% were polymorphic. The mean coefficient of gene differentiation (Gst was 0.388 and 0.341 indicating that 61.2% and 65.9% of the genetic variation resided within the populations. Analysis of molecular variance (AMOVA indicated that majority of genetic variation (94.6% using RAPD and 89% using SSR occurred among genotypes, while the variation between the three groups (categorized as tall, medium and small plants height was 5.4% (using RAPD and 11% (using SSR. The dendrogram obtained from NJ and STRUCTURE analysis revealed splitting of genotypes into four clusters with clear distinction between short, medium and tall height genotypes, indicated that genetic differentiations measure with respect to RAPD and SSR. However, both the markers were equally useful in providing some understanding about the genetic relationship of different genotypes of poplar that are important in the conservation and exploitation of poplar genetic resources.

  18. Evidence-based recommendations for monitoring bone disease and the response to enzyme replacement therapy in Gaucher patients.

    Science.gov (United States)

    Vom Dahl, Stephan; Poll, Ludger; Di Rocco, Maja; Ciana, Giovanni; Denes, Carmencita; Mariani, Giuliano; Maas, Mario

    2006-06-01

    Bone disease is a serious complication of Gaucher disease. Untreated, it can result in pain, permanent bone damage and disability. Enzyme replacement therapy reverses many of the clinical signs of Gaucher bone disease but early assessment and treatment, and regular monitoring, are essential in optimising outcomes. In September 2005, a group of European experts met to review current knowledge and identify best practice and unmet needs in the monitoring of Gaucher bone disease and the response to enzyme replacement therapy. Medline searches of peer-reviewed literature (no date restrictions) were conducted and supplemented by additional information considered relevant by panellists to furthering discussions. The group's recommendations included: currently used biochemical bone markers are not clinically practical or reliable; plain X-rays should not be the sole method of assessing bone disease; MRI is the most sensitive method for monitoring bone marrow infiltration by Gaucher cells; semi-quantitative methods for assessing bone marrow infiltration in routine clinical practice should use readily available technology, include an assessment of Gaucher cell infiltration in the lumbar spine and femur, and be validated for inter-rater reliability and in comparison to other methods; a multidisciplinary approach is required for the treatment of Gaucher patients; all Gaucher patients should receive a comprehensive initial radiologic evaluation for bone disease and ongoing radiological monitoring at least once every 2 years.

  19. [Development of molecular pharmacognosy in China based on bibliometric analysis].

    Science.gov (United States)

    Liu, Yang; Wang, Jun-Wen; Tong, Yuan-Yuan; Yang, Ce; Huang, Man-Ting; Lei, Lei; Li, Hai-Yan

    2016-03-01

    The method of bibliometrics was used to analyze the literature about the application of molecular biotechnique to pharmacognosy which were searched and obtained from the CNKI database and Shanghai intellectual property information platform from the year 1995 to 2015.It was found that 22 462 articles were published and the 63% were funded, 50 core institutions and 888 authors, 18 core journals were engaged in this subject.496 items of patents were authorized and 90 kinds of Chinese Materia Medica were involved.In the view of the quantity and quality of published literature, the scale and influence of journals, institutions, and the extent of subject categories have made remarkable achievement. Molecular pharmacognosy has completed the germination stage of a new subject, and has been in a relatively mature and stable development status. Copyright© by the Chinese Pharmaceutical Association.

  20. [Personalized urooncology based on molecular uropathology: what is the future?].

    Science.gov (United States)

    Dahl, E; Haller, F

    2013-07-01

    Targeted therapies and biomarker validation are key drivers in the advancement of personalized oncology which is a growing topic in all clinical areas. Compared with other professions, such as pulmonology and gynecology, development in urology has so far been retarded but has recently gained increasing momentum. A basis for this is the currently growing and in future accelerated application of new knowledge derived from molecular biology in the field of uropathology. The rapid gain of knowledge is driven by a whole new class of analytical methods, such as massively parallel sequencing (deep sequencing or next generation sequencing), which enables analysis of virtually a new universe of potential biomarkers. This article describes the emerging paradigm shift in molecular pathological diagnostics of urological tumors using the example of prostate cancer.

  1. Countrywise results of total hip replacement. An analysis of 438,733 hips based on the Nordic Arthroplasty Register Association database

    DEFF Research Database (Denmark)

    Mäkelä, Keijo T; Matilainen, Markus; Pulkkinen, Pekka

    2014-01-01

    Background and purpose An earlier Nordic Arthroplasty Register Association (NARA) report on 280,201 total hip replacements (THRs) based on data from 1995-2006, from Sweden, Norway, and Denmark, was published in 2009. The present study assessed THR survival according to country, based on the NARA...... database with the Finnish data included. Material and methods 438,733 THRs performed during the period 1995-2011 in Sweden, Denmark, Norway, and Finland were included. Kaplan-Meier survival analysis was used to calculate survival probabilities with 95% confidence interval (CI). Cox multiple regression...

  2. Adsorbate-driven cooling of carbene-based molecular junctions

    Czech Academy of Sciences Publication Activity Database

    Foti, Giuseppe; Vázquez, Héctor

    2017-01-01

    Roč. 8, Oct (2017), s. 2060-2068 ISSN 2190-4286 R&D Projects: GA ČR GA15-19672S EU Projects: European Commission(XE) 702114 - HEATEXMOL Institutional support: RVO:68378271 Keywords : adsorbate * carbene * current-induced heating and cooling * molecular junction * vibrations Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.127, year: 2016

  3. Extending the molecular clutch beyond actin-based cell motility

    International Nuclear Information System (INIS)

    Havrylenko, Svitlana; Mezanges, Xavier; Batchelder, Ellen; Plastino, Julie

    2014-01-01

    Many cell movements occur via polymerization of the actin cytoskeleton beneath the plasma membrane at the front of the cell, forming a protrusion called a lamellipodium, while myosin contraction squeezes forward the back of the cell. In what is known as the ‘molecular clutch’ description of cell motility, forward movement results from the engagement of the acto-myosin motor with cell-matrix adhesions, thus transmitting force to the substrate and producing movement. However during cell translocation, clutch engagement is not perfect, and as a result, the cytoskeleton slips with respect to the substrate, undergoing backward (retrograde) flow in the direction of the cell body. Retrograde flow is therefore inversely proportional to cell speed and depends on adhesion and acto-myosin dynamics. Here we asked whether the molecular clutch was a general mechanism by measuring motility and retrograde flow for the Caenorhabditis elegans sperm cell in different adhesive conditions. These cells move by adhering to the substrate and emitting a dynamic lamellipodium, but the sperm cell does not contain an acto-myosin cytoskeleton. Instead the lamellipodium is formed by the assembly of major sperm protein, which has no biochemical or structural similarity to actin. We find that these cells display the same molecular clutch characteristics as acto-myosin containing cells. We further show that retrograde flow is produced both by cytoskeletal assembly and contractility in these cells. Overall this study shows that the molecular clutch hypothesis of how polymerization is transduced into motility via adhesions is a general description of cell movement regardless of the composition of the cytoskeleton. (paper)

  4. Electron dopable molecular wires based on the extended viologens

    Czech Academy of Sciences Publication Activity Database

    Kolivoška, Viliam; Gál, Miroslav; Pospíšil, Lubomír; Valášek, Michal; Hromadová, Magdaléna

    2011-01-01

    Roč. 13, č. 23 (2011), s. 11422-11429 ISSN 1463-9076 R&D Projects: GA ČR GA203/08/1157; GA ČR GA203/09/0705; GA AV ČR IAA400400802; GA MŠk(CZ) MEB041006 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z40550506 Keywords : electron transfer * spectroelectrochemistry * molecular wires Subject RIV: CG - Electrochemistry Impact factor: 3.573, year: 2011

  5. Extending the molecular clutch beyond actin-based cell motility.

    Science.gov (United States)

    Havrylenko, Svitlana; Mezanges, Xavier; Batchelder, Ellen; Plastino, Julie

    2014-10-01

    Many cell movements occur via polymerization of the actin cytoskeleton beneath the plasma membrane at the front of the cell, forming a protrusion called a lamellipodium, while myosin contraction squeezes forward the back of the cell. In what is known as the "molecular clutch" description of cell motility, forward movement results from the engagement of the acto-myosin motor with cell-matrix adhesions, thus transmitting force to the substrate and producing movement. However during cell translocation, clutch engagement is not perfect, and as a result, the cytoskeleton slips with respect to the substrate, undergoing backward (retrograde) flow in the direction of the cell body. Retrograde flow is therefore inversely proportional to cell speed and depends on adhesion and acto-myosin dynamics. Here we asked whether the molecular clutch was a general mechanism by measuring motility and retrograde flow for the Caenorhabditis elegans sperm cell in different adhesive conditions. These cells move by adhering to the substrate and emitting a dynamic lamellipodium, but the sperm cell does not contain an acto-myosin cytoskeleton. Instead the lamellipodium is formed by the assembly of Major Sperm Protein (MSP), which has no biochemical or structural similarity to actin. We find that these cells display the same molecular clutch characteristics as acto-myosin containing cells. We further show that retrograde flow is produced both by cytoskeletal assembly and contractility in these cells. Overall this study shows that the molecular clutch hypothesis of how polymerization is transduced into motility via adhesions is a general description of cell movement regardless of the composition of the cytoskeleton.

  6. Epidemiological bases and molecular mechanisms linking obesity, diabetes, and cancer.

    Science.gov (United States)

    Gutiérrez-Salmerón, María; Chocarro-Calvo, Ana; García-Martínez, José Manuel; de la Vieja, Antonio; García-Jiménez, Custodia

    2017-02-01

    The association between diabetes and cancer was hypothesized almost one century ago. Today, a vast number of epidemiological studies support that obese and diabetic populations are more likely to experience tissue-specific cancers, but the underlying molecular mechanisms remain unknown. Obesity, diabetes, and cancer share many hormonal, immune, and metabolic changes that may account for the relationship between diabetes and cancer. In addition, antidiabetic treatments may have an impact on the occurrence and course of some cancers. Moreover, some anticancer treatments may induce diabetes. These observations aroused a great controversy because of the ethical implications and the associated commercial interests. We report an epidemiological update from a mechanistic perspective that suggests the existence of many common and differential individual mechanisms linking obesity and type 1 and 2 diabetes mellitus to certain cancers. The challenge today is to identify the molecular links responsible for this association. Classification of cancers by their molecular signatures may facilitate future mechanistic and epidemiological studies. Copyright © 2016 SEEN. Publicado por Elsevier España, S.L.U. All rights reserved.

  7. Comprehensive characterization of molecular interactions based on nanomechanics.

    Directory of Open Access Journals (Sweden)

    Murali Krishna Ghatkesar

    Full Text Available Molecular interaction is a key concept in our understanding of the biological mechanisms of life. Two physical properties change when one molecular partner binds to another. Firstly, the masses combine and secondly, the structure of at least one binding partner is altered, mechanically transducing the binding into subsequent biological reactions. Here we present a nanomechanical micro-array technique for bio-medical research, which not only monitors the binding of effector molecules to their target but also the subsequent effect on a biological system in vitro. This label-free and real-time method directly and simultaneously tracks mass and nanomechanical changes at the sensor interface using micro-cantilever technology. To prove the concept we measured lipid vesicle (approximately 748*10(6 Da adsorption on the sensor interface followed by subsequent binding of the bee venom peptide melittin (2840 Da to the vesicles. The results show the high dynamic range of the instrument and that measuring the mass and structural changes simultaneously allow a comprehensive discussion of molecular interactions.

  8. Molecular epidemiology of Salmonella enterica serovar typhimurium isolates from cattle in hokkaido, Japan: evidence of clonal replacement and characterization of the disseminated clone.

    Science.gov (United States)

    Tamamura, Yukino; Uchida, Ikuo; Tanaka, Kiyoshi; Okazaki, Hizuru; Tezuka, Satoru; Hanyu, Hideki; Kataoka, Natsumi; Makino, Sou-Ichi; Kishima, Masato; Kubota, Takayuki; Kanno, Toru; Hatama, Shinichi; Ishihara, Ryoko; Hata, Eiji; Yamada, Hironari; Nakaoka, Yuuji; Akiba, Masato

    2011-03-01

    The molecular epidemiology of 545 Salmonella enterica serovar Typhimurium isolates collected between 1977 and 2009 from cattle in Hokkaido, Japan, was investigated using pulsed-field gel electrophoresis (PFGE). Nine main clusters were identified from 116 PFGE patterns. Cluster I comprised 248 isolates, 243 of which possessed a sequence specific to definitive phage type 104 (DT104) or U302. The cluster I isolates were dominant in 1993 to 2003, but their numbers declined beginning in 2004. Beginning in 2002, an increase was observed in the number of cluster VII isolates, consisting of 21 PFGE patterns comprising 165 isolates. A total of 116 isolates representative of the 116 PFGE profiles were analyzed by multilocus variable-number tandem-repeat analysis (MLVA). Other than two drug-sensitive isolates, 19 isolates within cluster VII were classified in the same cluster by MLVA. Among the cluster VII isolates, an antibiotic resistance type showing resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides, tetracycline, kanamycin, cefazolin, and sulfamethoxazole-trimethoprim and a resistance type showing resistance to ampicillin, streptomycin, sulfonamides, tetracycline, and kanamycin were found in 23 and 125 isolates, respectively. In the 19 isolates representative of cluster VII, the bla(TEM-1) gene was found on a Salmonella serotype Typhimurium virulence plasmid, which was transferred to Escherichia coli by electroporation along with resistance to two to four other antimicrobials. Genomic analysis by subtractive hybridization and plasmid analysis suggested that the bla(TEM-1)-carrying virulence plasmid has a mosaic structure composed of elements of different origin. These results indicate an emerging multidrug-resistant S. Typhimurium clone carrying a virulence-resistance plasmid among cattle in Hokkaido, Japan.

  9. Molecular Epidemiology of Salmonella enterica Serovar Typhimurium Isolates from Cattle in Hokkaido, Japan: Evidence of Clonal Replacement and Characterization of the Disseminated Clone▿ †

    Science.gov (United States)

    Tamamura, Yukino; Uchida, Ikuo; Tanaka, Kiyoshi; Okazaki, Hizuru; Tezuka, Satoru; Hanyu, Hideki; Kataoka, Natsumi; Makino, Sou-ichi; Kishima, Masato; Kubota, Takayuki; Kanno, Toru; Hatama, Shinichi; Ishihara, Ryoko; Hata, Eiji; Yamada, Hironari; Nakaoka, Yuuji; Akiba, Masato

    2011-01-01

    The molecular epidemiology of 545 Salmonella enterica serovar Typhimurium isolates collected between 1977 and 2009 from cattle in Hokkaido, Japan, was investigated using pulsed-field gel electrophoresis (PFGE). Nine main clusters were identified from 116 PFGE patterns. Cluster I comprised 248 isolates, 243 of which possessed a sequence specific to definitive phage type 104 (DT104) or U302. The cluster I isolates were dominant in 1993 to 2003, but their numbers declined beginning in 2004. Beginning in 2002, an increase was observed in the number of cluster VII isolates, consisting of 21 PFGE patterns comprising 165 isolates. A total of 116 isolates representative of the 116 PFGE profiles were analyzed by multilocus variable-number tandem-repeat analysis (MLVA). Other than two drug-sensitive isolates, 19 isolates within cluster VII were classified in the same cluster by MLVA. Among the cluster VII isolates, an antibiotic resistance type showing resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides, tetracycline, kanamycin, cefazolin, and sulfamethoxazole-trimethoprim and a resistance type showing resistance to ampicillin, streptomycin, sulfonamides, tetracycline, and kanamycin were found in 23 and 125 isolates, respectively. In the 19 isolates representative of cluster VII, the blaTEM-1 gene was found on a Salmonella serotype Typhimurium virulence plasmid, which was transferred to Escherichia coli by electroporation along with resistance to two to four other antimicrobials. Genomic analysis by subtractive hybridization and plasmid analysis suggested that the blaTEM-1-carrying virulence plasmid has a mosaic structure composed of elements of different origin. These results indicate an emerging multidrug-resistant S. Typhimurium clone carrying a virulence-resistance plasmid among cattle in Hokkaido, Japan. PMID:21239560

  10. Drug Repositioning by Kernel-Based Integration of Molecular Structure, Molecular Activity, and Phenotype Data

    Science.gov (United States)

    Wang, Yongcui; Chen, Shilong; Deng, Naiyang; Wang, Yong

    2013-01-01

    Computational inference of novel therapeutic values for existing drugs, i.e., drug repositioning, offers the great prospect for faster and low-risk drug development. Previous researches have indicated that chemical structures, target proteins, and side-effects could provide rich information in drug similarity assessment and further disease similarity. However, each single data source is important in its own way and data integration holds the great promise to reposition drug more accurately. Here, we propose a new method for drug repositioning, PreDR (Predict Drug Repositioning), to integrate molecular structure, molecular activity, and phenotype data. Specifically, we characterize drug by profiling in chemical structure, target protein, and side-effects space, and define a kernel function to correlate drugs with diseases. Then we train a support vector machine (SVM) to computationally predict novel drug-disease interactions. PreDR is validated on a well-established drug-disease network with 1,933 interactions among 593 drugs and 313 diseases. By cross-validation, we find that chemical structure, drug target, and side-effects information are all predictive for drug-disease relationships. More experimentally observed drug-disease interactions can be revealed by integrating these three data sources. Comparison with existing methods demonstrates that PreDR is competitive both in accuracy and coverage. Follow-up database search and pathway analysis indicate that our new predictions are worthy of further experimental validation. Particularly several novel predictions are supported by clinical trials databases and this shows the significant prospects of PreDR in future drug treatment. In conclusion, our new method, PreDR, can serve as a useful tool in drug discovery to efficiently identify novel drug-disease interactions. In addition, our heterogeneous data integration framework can be applied to other problems. PMID:24244318

  11. Defining line replaceable units

    NARCIS (Netherlands)

    Parada Puig, J.E.; Basten, Robertus Johannes Ida

    2015-01-01

    Defective capital assets may be quickly restored to their operational condition by replacing the item that has failed. The item that is replaced is called the Line Replaceable Unit (LRU), and the so-called LRU definition problem is the problem of deciding on which item to replace upon each type of

  12. MOLECULAR-DYNAMICS SIMULATIONS OF CARBOHYDRATE-BASED SURFACTANTS IN SURFACTANT WATER OIL SYSTEMS

    NARCIS (Netherlands)

    VANBUUREN, AR; BERENDSEN, HJC

    Molecular dynamics simulations of two monolayers of carbohydrate-based surfactants (decyl alpha-glucoside and decyl beta-glucoside) at the interface between liquid decane and liquid water have been performed with the purpose to study the properties of these monolayers on a molecular and atomic

  13. Molecular modeling of protonic acid doping of emeraldine base polyaniline for chemical sensors

    NARCIS (Netherlands)

    Chen, X.; Yuan, C.A.; Wong, C.K.Y.; Ye, H.; Leung, S.Y.Y.; Zhang, G.

    2012-01-01

    We proposed a molecular modeling methodology to study the protonic acid doping of emeraldine base polyaniline which can used in gas detection. The commercial forcefield COMPASS was used for the polymer and protonic acid molecules. The molecular model, which is capable of representing the polyaniline

  14. Study of the voxel-based specific regional analysis system for Alzheimer's disease imaging sequence after magnetic resonance apparatus replacement

    International Nuclear Information System (INIS)

    Tsukagoshi, Yuki; Kanai, Yoshihiro; Yasui, Gou; Abe, Yuuji; Maemura, Keisuke; Nakazawa, Masaki; Yamaji, Yuugo; Mihara, Ban

    2012-01-01

    In our institute, an MR apparatus, MAGNETOM VISION (Siemens) was replaced by ECHELON Vega (HITACHI). Z-score data acquired by MPRAGE (VISION) was compared with those by radio frequency-spoiled steady-state acquisition with rewinded gradient echo (RSSG) and gradient echo inversion recovery (GEIR) (ECHELON). For this study, ten normal volunteers were recruited and their data ware obtained within two months using both apparatuses. In addition, the difference of the contrasts of the images of these apparatuses was compared. There was a significant difference between Z-scores of MPRAGE and RSSG while there was no difference between MPRAGE and GEIR. As for the contrast, data of MPRAGE were similar to those of GEIR. To compare Z-scores acquired with MAGNTOM VISION (Siemens), it seems appropriate to use GEIR in ECHELON Vega. (author)

  15. Potential applications of plant based derivatives as fat replacers, antioxidants and antimicrobials in fresh and processed meat products.

    Science.gov (United States)

    Hygreeva, Desugari; Pandey, M C; Radhakrishna, K

    2014-09-01

    Growing concern about diet and health has led to development of healthier food products. In general consumer perception towards the intake of meat and meat products is unhealthy because it may increase the risk of diseases like cardiovascular diseases, obesity and cancer, because of its high fat content (especially saturated fat) and added synthetic antioxidants and antimicrobials. Addition of plant derivatives having antioxidant components including vitamins A, C and E, minerals, polyphenols, flavanoids and terpenoids in meat products may decrease the risk of several degenerative diseases. To change consumer attitudes towards meat consumption, the meat industry is undergoing major transformations by addition of nonmeat ingredients as animal fat replacers, natural antioxidants and antimicrobials, preferably derived from plant sources. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Nonequilibrium molecular dynamics

    Directory of Open Access Journals (Sweden)

    Wm.G.Hoover

    2005-01-01

    Full Text Available Nonequilibrium Molecular Dynamics is a powerful simulation tool. Like its equilibrium cousin, nonequilibrium molecular dynamics is based on time-reversible equations of motion. But unlike conventional mechanics, nonequilibrium molecular dynamics provides a consistent microscopic basis for the irreversible macroscopic Second Law of Thermodynamics. We recall here how fast computers led to the development of nonequilibrium molecular dynamics from the statistical mechanics of the 1950s. Computer-based theories facilitated revolutionary breakthroughs in understanding during the 1970s and 1980s. The new idea key to the nonequilibrium development was the replacement of the external thermodynamic environment by internal control variables. The new variables can control temperature, or pressure, or energy, or stress, or heat flux. These thermostat, barostat, ergostat, ... variables can control and maintain nonequilibrium states. We illustrate the methods with a simple example well-suited to student exploration, a thermostatted harmonic oscillator exposed to a temperature gradient.

  17. BASES MOLECULARES DA ABSORÇÃO DO FERRO

    OpenAIRE

    A. A. MACHADO; C. IZUMI; O. de FREITAS

    2009-01-01

    O ferro é um elemento essencial a todos os organismos vivos e alterações em sua homeostase resultam em quadro de deficiência ou acúmulo, ambos com alta prevalência e relevância clínica. A última década foi marcada pela geração de conhecimentos importantes, que estão contribuindo para a elucidação dos mecanismos moleculares da homeostase do ferro. Foram identificadas ...

  18. Molecular interactions of nucleic acid bases. From ab initio calculations to molecular dynamics simulations

    Czech Academy of Sciences Publication Activity Database

    Šponer, Jiří

    2002-01-01

    Roč. 223, - (2002), s. 212 ISSN 0065-7727. [Annual Meeting of the American Chemistry Society /223./. 07.04.2002-11.04.2002, Orlando ] Institutional research plan: CEZ:AV0Z5004920 Keywords : quantum chemistry * base pairing * base stacking Subject RIV: BO - Biophysics

  19. Hybrid nanomembrane-based capacitors for the determination of the dielectric constant of semiconducting molecular ensembles.

    Science.gov (United States)

    Petrini, Paula Andreia; Lopes da Silva, Ricardo Magno; de Oliveira, Rafael Furlan; Merces, Leandro; Bufon, Carlos César Bof

    2018-04-06

    Considerable advances in the field of molecular electronics have been achieved over the recent years. One persistent challenge, however, is the exploitation of the electronic properties of molecules fully integrated into devices. Typically, the molecular electronic properties are investigated using sophisticated techniques incompatible with a practical device technology, such as the scanning tunneling microscope (STM). The incorporation of molecular materials in devices is not a trivial task since the typical dimensions of electrical contacts are much larger than the molecular ones. To tackle this issue, we report on hybrid capacitors using mechanically-compliant nanomembranes to encapsulate ultrathin molecular ensembles for the investigation of molecular dielectric properties. As the prototype material, copper (II) phthalocyanine (CuPc) has been chosen as information on its dielectric constant (kCuPc) at the molecular scale is missing. Here, hybrid nanomembrane-based capacitors containing metallic nanomembranes, insulating Al2O3 layers, and the CuPc molecular ensemble have been fabricated and evaluated. The Al2O3 is used to prevent short circuits through the capacitor plates as the molecular layer is considerably thin (< 30 nm). From the electrical measurements of devices with molecular layers of different thicknesses, the CuPc dielectric constant has been reliably determined (kCuPc = 4.5 ± 0.5). These values suggest a mild contribution of molecular orientation in the CuPc dielectric properties. The reported nanomembrane-based capacitor is a viable strategy for the dielectric characterization of ultrathin molecular ensembles integrated into a practical, real device technology. © 2018 IOP Publishing Ltd.

  20. Fragment Molecular Orbital method-based Molecular Dynamics (FMO-MD) as a simulator for chemical reactions in explicit solvation.

    Science.gov (United States)

    Komeiji, Yuto; Ishikawa, Takeshi; Mochizuki, Yuji; Yamataka, Hiroshi; Nakano, Tatsuya

    2009-01-15

    Fragment Molecular Orbital based-Molecular Dynamics (FMO-MD, Komeiji et al., Chem Phys Lett 2003, 372, 342) is an ab initio MD method suitable for large molecular systems. Here, FMO-MD was implemented to conduct full quantum simulations of chemical reactions in explicit solvation. Several FMO-MD simulations were performed for a sphere of water to find a suitable simulation protocol. It was found that annealing of the initial configuration by a classical MD brought the subsequent FMO-MD trajectory to faster stabilization, and also that use of bond constraint in the FMO-MD heating stage effectively reduced the computation time. Then, the blue moon ensemble method (Sprik and Ciccotti, J Chem Phys 1998, 109, 7737) was implemented and was tested by calculating free energy profiles of the Menschutkin reaction (H3N + CH3Cl --> +H3NCH3 + Cl-) in the presence and absence of the solvent water via FMO-MD. The obtained free energy profiles were consistent with the Hammond postulate in that stabilization of the product by the solvent, namely hydration of Cl-, shifted the transition state to the reactant-side. Based on these FMO-MD results, plans for further improvement of the method are discussed. Copyright 2008 Wiley Periodicals, Inc.

  1. Fishing the molecular bases of Treacher Collins syndrome.

    Directory of Open Access Journals (Sweden)

    Andrea M J Weiner

    Full Text Available Treacher Collins syndrome (TCS is an autosomal dominant disorder of craniofacial development, and mutations in the TCOF1 gene are responsible for over 90% of TCS cases. The knowledge about the molecular mechanisms responsible for this syndrome is relatively scant, probably due to the difficulty of reproducing the pathology in experimental animals. Zebrafish is an emerging model for human disease studies, and we therefore assessed it as a model for studying TCS. We identified in silico the putative zebrafish TCOF1 ortholog and cloned the corresponding cDNA. The derived polypeptide shares the main structural domains found in mammals and amphibians. Tcof1 expression is restricted to the anterior-most regions of zebrafish developing embryos, similar to what happens in mouse embryos. Tcof1 loss-of-function resulted in fish showing phenotypes similar to those observed in TCS patients, and enabled a further characterization of the mechanisms underlying craniofacial malformation. Besides, we initiated the identification of potential molecular targets of treacle in zebrafish. We found that Tcof1 loss-of-function led to a decrease in the expression of cellular proliferation and craniofacial development. Together, results presented here strongly suggest that it is possible to achieve fish with TCS-like phenotype by knocking down the expression of the TCOF1 ortholog in zebrafish. This experimental condition may facilitate the study of the disease etiology during embryonic development.

  2. Fishing the molecular bases of Treacher Collins syndrome.

    Science.gov (United States)

    Weiner, Andrea M J; Scampoli, Nadia L; Calcaterra, Nora B

    2012-01-01

    Treacher Collins syndrome (TCS) is an autosomal dominant disorder of craniofacial development, and mutations in the TCOF1 gene are responsible for over 90% of TCS cases. The knowledge about the molecular mechanisms responsible for this syndrome is relatively scant, probably due to the difficulty of reproducing the pathology in experimental animals. Zebrafish is an emerging model for human disease studies, and we therefore assessed it as a model for studying TCS. We identified in silico the putative zebrafish TCOF1 ortholog and cloned the corresponding cDNA. The derived polypeptide shares the main structural domains found in mammals and amphibians. Tcof1 expression is restricted to the anterior-most regions of zebrafish developing embryos, similar to what happens in mouse embryos. Tcof1 loss-of-function resulted in fish showing phenotypes similar to those observed in TCS patients, and enabled a further characterization of the mechanisms underlying craniofacial malformation. Besides, we initiated the identification of potential molecular targets of treacle in zebrafish. We found that Tcof1 loss-of-function led to a decrease in the expression of cellular proliferation and craniofacial development. Together, results presented here strongly suggest that it is possible to achieve fish with TCS-like phenotype by knocking down the expression of the TCOF1 ortholog in zebrafish. This experimental condition may facilitate the study of the disease etiology during embryonic development.

  3. Specific interactions and binding energies between thermolysin and potent inhibitors: molecular simulations based on ab initio molecular orbital method.

    Science.gov (United States)

    Hirakawa, Tatsuya; Fujita, Seiya; Ohyama, Tatsuya; Dedachi, Kenichi; Khan, Mahmud Tareq Hassan; Sylte, Ingebrigt; Kurita, Noriyuki

    2012-03-01

    Biochemical functions of the metalloprotease thermolysin (TLN) are controlled by various inhibitors. In a recent study we identified 12 compounds as TLN inhibitors by virtual screening and in vitro competitive binding assays. However, the specific interactions between TLN and these inhibitors have not been clarified. We here investigate stable structures of the solvated TLN-inhibitor complexes by classical molecular mechanics simulations and elucidate the specific interactions between TLN and these inhibitors at an electronic level by using ab initio fragment molecular orbital (FMO) calculations. The calculated binding energies between TLN and the inhibitors are qualitatively consistent with the experimental results, and the FMO results elucidate important amino acid residues of TLN for inhibitor binding. Based on the calculated results, we propose a novel potent inhibitor having a large binding affinity to TLN. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Effect of early supervised progressive resistance training compared to unsupervised home-based exercise after fast-track total hip replacement applied to patients with preoperative functional limitations

    DEFF Research Database (Denmark)

    Mikkelsen, L R; Mechlenburg, I; Søballe, K

    2014-01-01

    OBJECTIVE: To examine if 2 weekly sessions of supervised progressive resistance training (PRT) in combination with 5 weekly sessions of unsupervised home-based exercise is more effective than 7 weekly sessions of unsupervised home-based exercise in improving leg-extension power of the operated leg...... 10 weeks after total hip replacement (THR) in patients with lower pre-operative function. METHOD: A total of 73 patients scheduled for THR were randomised (1:1) to intervention group (IG, home based exercise 5 days/week and PRT 2 days/week) or control group (CG, home based exercise 7 days...... of the operated leg, at the primary endpoint 10 weeks after surgery in THR patients with lower pre-operative function. TRIAL REGISTRATION: NCT01214954....

  5. Molecular basis of Acute Myelogenous Leukemia As bases moleculares da leucemia mielóide aguda

    Directory of Open Access Journals (Sweden)

    Eduardo M. Rego

    2002-01-01

    Full Text Available Acute Myelogenous Leukemia (AML is frequently associated with recurring chromosomal translocations, which lead to the fusion of two genes encoding transcription factors. As the moieties of these fusion proteins retain part of the functional domains of the wild-type proteins, they may interfere directly or indirectly with the transcriptional regulation of the leukemic cell, conferring survival advantage. The majority of the transcription factors commonly involved in recurring chromosomal translocations may be grouped in one of the following families: core binding factor (CBF, retinoic acid receptor alpha (RARalpha, homeobox (HOX family, and mixed lineage leukemia (MLL. In vivo analysis of the molecular basis of leukemogenesis through the generation of transgenic mouse models revealed that a common theme is the recruitment of transcriptional co-activators and co-repressors by these fusion proteins. However, the expression of the fusion protein is not sufficient to induce full blown leukemia, as evidenced in part by the long latencies required for disease development in the transgenic models of leukemia, and therefore, second mutagenic events may contribute to AML pathogenesis.A leucemia mielóide aguda (LMA está freqüentemente associada a translocações cromossômicas recorrentes. Em muitos casos, os genes presentes nos pontos de quebra cromossômica são conhecidos e, quase todos codificam para fatores de transcrição. O gene híbrido, resultante da justaposição de exons de genes distintos, codifica para proteínas de fusão. Como estas retêm a maior parte dos domínios funcionais das proteínas selvagens, elas interferem direta ou indiretamente com regulação da transcrição gênica, conferindo vantagem à sobrevivência das células leucêmicas. A maioria dos fatores de transcrição afetados pelas translocações cromossômicas associadas a LMA pode ser agrupada numa das seguintes famílias: dos core binding factors (CBF, do receptor

  6. An update on hormone replacement therapy: health and medicine for women: a multidisciplinary, evidence-based review of mid-life health concerns.

    Science.gov (United States)

    Shook, Lydia L

    2011-03-01

    The Department of Obstetrics, Gynecology, and Reproductive Sciences at the Yale School of Medicine hosted a daylong continuing medical education (CME) symposium titled "Health and Medicine for Women: A Multidisciplinary, Evidence-Based Review of Mid-Life Health Concerns" in September 2010. A number of speakers discussed current research on hormone replacement therapy (HRT) and re-evaluated the results of the Women's Health Initiative (WHI), a landmark, randomized, placebo-controlled trial that still sparks debate almost a decade after its conclusion. This article summarizes this discussion and highlights directions for future study.

  7. Molecular MR Imaging of CD44 in Breast Cancer with Hyaluronan-Based Contrast Agents

    Science.gov (United States)

    2009-09-01

    both Gd groups for MR imaging and cytotoxic moieties can be used as a unique biocompatible platform for theranostic applications in breast cancer ...TITLE: Molecular MR Imaging of CD44 in Breast Cancer with Hyaluronan-Based Contrast Agents PRINCIPAL INVESTIGATOR: Dmitri Artemov, Ph.D...AUG 2009 - 4. TITLE AND SUBTITLE Molecular MR Imaging of CD44 in Breast Cancer with Hyaluronan-Based Contrast Agents 5a. CONTRACT

  8. Accelerating convergence of molecular dynamics-based structural relaxation

    DEFF Research Database (Denmark)

    Christensen, Asbjørn

    2005-01-01

    the influence of spectral properties and dimensionality of the molecular system on the algorithm efficiency. We test two algorithms, the MinMax and Lanczos, for spectral estimation from an MD trajectory, and use this to derive a practical scheme of time step adaptation in MD relaxation algorithms to improve...... efficiency. We also discuss the implementation aspects. Secondly, we explore the final state refinement acceleration by a combination with the conjugate gradient technique, where the key ingredient is an implicit corrector step. Finally, we test the feasibility of passive Hessian matrix accumulation from...... an MD trajectory, as another route for final phase acceleration. Our suggestions may be implemented within most MD quench implementations with a few, straightforward lines of code, thus maintaining the appealing simplicity of the MD quench algorithms. In this paper, we also bridge the conceptual gap...

  9. Molecular bases of cellular senescence: Hayflick phenomenon 50 years later

    Directory of Open Access Journals (Sweden)

    Patrycja Sosińska

    2016-03-01

    Full Text Available Normal human somatic cells have strictly limited proliferative capacity and reach a state of senescence when it becomes exhausted. It is believed that senescence is a response to extensive and irreparable DNA injury, localized in telomeric and/or non-telomeric regions of the genome. Main cause of this damage is oxidative stress, increasing due to deteriorated function of mitochondria. Senescent cells accumulate in tissues during aging, which is causatively linked with the development of various pathologies in elderly individuals, including cancer. This paper, prepared exactly 50 years after Leonard Hayflick’s discovery of the relationship between cellular senescence and organismal aging is aimed at presenting the current knowledge about molecular determinants of senescence, with particular emphasis paid to the role of oxidative stress, effectors of senescence at the level of cell cycle, markers of this phenomenon, and the effect of senescent cells on the development of certain age-related diseases.

  10. ChemPreview: an augmented reality-based molecular interface.

    Science.gov (United States)

    Zheng, Min; Waller, Mark P

    2017-05-01

    Human computer interfaces make computational science more comprehensible and impactful. Complex 3D structures such as proteins or DNA are magnified by digital representations and displayed on two-dimensional monitors. Augmented reality has recently opened another door to access the virtual three-dimensional world. Herein, we present an augmented reality application called ChemPreview with the potential to manipulate bio-molecular structures at an atomistic level. ChemPreview is available at https://github.com/wallerlab/chem-preview/releases, and is built on top of the Meta 1 platform https://www.metavision.com/. ChemPreview can be used to interact with a protein in an intuitive way using natural hand gestures, thereby making it appealing to computational chemists or structural biologists. The ability to manipulate atoms in real world could eventually provide new and more efficient ways of extracting structural knowledge, or designing new molecules in silico. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Genetic diversity analysis of common beans based on molecular markers

    Directory of Open Access Journals (Sweden)

    Homar R. Gill-Langarica

    2011-01-01

    Full Text Available A core collection of the common bean (Phaseolus vulgaris L., representing genetic diversity in the entire Mexican holding, is kept at the INIFAP (Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias, Mexico Germplasm Bank. After evaluation, the genetic structure of this collection (200 accessions was compared with that of landraces from the states of Oaxaca, Chiapas and Veracruz (10 genotypes from each, as well as a further 10 cultivars, by means of four amplified fragment length polymorphisms (AFLP +3/+3 primer combinations and seven simple sequence repeats (SSR loci, in order to define genetic diversity, variability and mutual relationships. Data underwent cluster (UPGMA and molecular variance (AMOVA analyses. AFLP analysis produced 530 bands (88.5% polymorphic while SSR primers amplified 174 alleles, all polymorphic (8.2 alleles per locus. AFLP indicated that the highest genetic diversity was to be found in ten commercial-seed classes from two major groups of accessions from Central Mexico and Chiapas, which seems to be an important center of diversity in the south. A third group included genotypes from Nueva Granada, Mesoamerica, Jalisco and Durango races. Here, SSR analysis indicated a reduced number of shared haplotypes among accessions, whereas the highest genetic components of AMOVA variation were found within accessions. Genetic diversity observed in the common-bean core collection represents an important sample of the total Phaseolus genetic variability at the main Germplasm Bank of INIFAP. Molecular marker strategies could contribute to a better understanding of the genetic structure of the core collection as well as to its improvement and validation.

  12. IMU-based Real-time Pose Measurement system for Anterior Pelvic Plane in Total Hip Replacement Surgeries.

    Science.gov (United States)

    Zhe Cao; Shaojie Su; Hao Tang; Yixin Zhou; Zhihua Wang; Hong Chen

    2017-07-01

    With the aging of population, the number of Total Hip Replacement Surgeries (THR) increased year by year. In THR, inaccurate position of the implanted prosthesis may lead to the failure of the operation. In order to reduce the failure rate and acquire the real-time pose of Anterior Pelvic Plane (APP), we propose a measurement system in this paper. The measurement system includes two parts: Initial Pose Measurement Instrument (IPMI) and Real-time Pose Measurement Instrument (RPMI). IPMI is used to acquire the initial pose of the APP, and RPMI is used to estimate the real-time pose of the APP. Both are composed of an Inertial Measurement Unit (IMU) and magnetometer sensors. To estimate the attitude of the measurement system, the Extended Kalman Filter (EKF) is adopted in this paper. The real-time pose of the APP could be acquired together with the algorithm designed in the paper. The experiment results show that the Root Mean Square Error (RMSE) is within 1.6 degrees, which meets the requirement of THR operations.

  13. Transforming bases to bytes: Molecular computing with DNA

    Indian Academy of Sciences (India)

    Despite the popular image of silicon-based computers for computation, an embryonic field of mole- cular computation is emerging, where molecules in solution perform computational ..... [4] Mao C, Sun W, Shen Z and Seeman N C 1999. A nanomechanical device based on the B-Z transition of DNA; Nature 397 144–146.

  14. Molecular-based recursive partitioning analysis model for glioblastoma in the temozolomide era a correlative analysis based on nrg oncology RTOG 0525

    NARCIS (Netherlands)

    Bell, Erica Hlavin; Pugh, Stephanie L.; McElroy, Joseph P.; Gilbert, Mark R.; Mehta, Minesh; Klimowicz, Alexander C.; Magliocco, Anthony; Bredel, Markus; Robe, Pierre|info:eu-repo/dai/nl/413970957; Grosu, Anca L.; Stupp, Roger; Curran, Walter; Becker, Aline P.; Salavaggione, Andrea L.; Barnholtz-Sloan, Jill S.; Aldape, Kenneth; Blumenthal, Deborah T.; Brown, Paul D.; Glass, Jon; Souhami, Luis; Lee, R. Jeffrey; Brachman, David; Flickinger, John; Won, Minhee; Chakravarti, Arnab

    2017-01-01

    IMPORTANCE: There is a need for a more refined, molecularly based classification model for glioblastoma (GBM) in the temozolomide era. OBJECTIVE: To refine the existing clinically based recursive partitioning analysis (RPA) model by incorporating molecular variables. DESIGN, SETTING, AND

  15. Establishment of a Molecular Serotyping Scheme and a Multiplexed Luminex-Based Array for Enterobacter aerogenes.

    Science.gov (United States)

    Guo, Xi; Wang, Min; Wang, Lu; Wang, Yao; Chen, Tingting; Wu, Pan; Chen, Min; Liu, Bin; Feng, Lu

    2018-01-01

    Serotyping based on surface polysaccharide antigens is important for the clinical detection and epidemiological surveillance of pathogens. Polysaccharide gene clusters (PSgcs) are typically responsible for the diversity of bacterial surface polysaccharides. Through whole-genome sequencing and analysis, eight putative PSgc types were identified in 23 Enterobacter aerogenes strains from several geographic areas, allowing us to present the first molecular serotyping system for E. aerogenes . A conventional antigenic scheme was also established and correlated well with the molecular serotyping system that was based on PSgc genetic variation, indicating that PSgc-based molecular typing and immunological serology provide equally valid results. Further, a multiplex Luminex-based array was developed, and a double-blind test was conducted with 97 clinical specimens from Shanghai, China, to validate our array. The results of these analyses indicated that strains containing PSgc4 and PSgc7 comprised the predominant groups. We then examined 86 publicly available E. aerogenes strain genomes and identified an additional seven novel PSgc types, with PSgc10 being the most abundant type. In total, our study identified 15 PSgc types in E. aerogenes , providing the basis for a molecular serotyping scheme. From these results, differing epidemic patterns were identified between strains that were predominant in different regions. Our study highlights the feasibility and reliability of a serotyping system based on PSgc diversity, and for the first time, presents a molecular serotyping system, as well as an antigenic scheme for E. aerogenes , providing the basis for molecular diagnostics and epidemiological surveillance of this important emerging pathogen.

  16. Descifrando las bases moleculares de la resistencia cuantitativa

    Directory of Open Access Journals (Sweden)

    Camilo Lopez

    2011-05-01

    Full Text Available Uno de los factores mas importantes que afectan los cultivos son las enfermedades ocasionadas por los patógenos. La resistencia vegetal ha sido clásicamente dividida en dos tipos: i competa, vertical o cualitativa que es gobernada por un solo gen y ii incompleta, horizontal o cuantitativa la cual es gobernada por varios genes. Aunque la resistencia cuantitativa provee resistencia de amplio espectro y es durable, los mecanismo moleculares subyacentes no han sido estudiados en detalle. En esta revisión se propone un modelo basado en la co-localización de genes similares a los clásicos genes de resistencia cualitativa con QTLs (Quantitative Trait Loci para explicar el mecanismo involucrado en el reconocimiento del patógeno durante la resistencia cuantitativa. Además se presenta información acerca del progreso obtenido en los últimos tres años para entender este tipo de resistencia, que culminó con la clonación de varios genes asociados a la resistencia cuantitativa. En conjunto, estos datos proveen nuevas luces sobre la naturaleza genética de este tipo de resistencia y de cómo puede ser empleada en programas de mejoramiento genético.

  17. Molecular Bases and Phenotypic Determinants of Aromatase Excess Syndrome

    Directory of Open Access Journals (Sweden)

    Maki Fukami

    2012-01-01

    Full Text Available Aromatase excess syndrome (AEXS is a rare autosomal dominant disorder characterized by gynecomastia. This condition is caused by overexpression of CYP19A1 encoding aromatase, and three types of cryptic genomic rearrangement around CYP19A1, that is, duplications, deletions, and inversions, have been identified in AEXS. Duplications appear to have caused CYP19A1 overexpression because of an increased number of physiological promoters, whereas deletions and inversions would have induced wide CYP19A1 expression due to the formation of chimeric genes consisting of a noncoding exon(s of a neighboring gene and CYP19A1 coding exons. Genotype-phenotype analysis implies that phenotypic severity of AEXS is primarily determined by the expression pattern of CYP19A1 and the chimeric genes and by the structural property of the fused exons with a promoter function (i.e., the presence or the absence of a natural translation start codon. These results provide novel information about molecular mechanisms of human genetic disorders and biological function of estrogens.

  18. Replacing a Missing Tooth

    Science.gov (United States)

    ... there are two options for replacement: First, a removable partial denture may be used to replace the missing tooth. ... appearance look and feel more natural than a removable partial denture. However, it does require grinding down the support ...

  19. Ankle replacement - discharge

    Science.gov (United States)

    ... total - discharge; Total ankle arthroplasty - discharge; Endoprosthetic ankle replacement - discharge; Osteoarthritis - ankle ... You had an ankle replacement. Your surgeon removed and reshaped ... an artificial ankle joint. You received pain medicine and were ...

  20. Artificial Disc Replacement

    Science.gov (United States)

    ... Spondylolisthesis BLOG FIND A SPECIALIST Treatments Artificial Disc Replacement (ADR) Patient Education Committee Jamie Baisden The disc ... Disc An artificial disc (also called a disc replacement, disc prosthesis or spine arthroplasty device) is a ...

  1. Elbow replacement - discharge

    Science.gov (United States)

    Total elbow arthroplasty - discharge; Endoprosthetic elbow replacement - discharge ... Pain is normal after elbow replacement surgery. It should get better over time. Your doctor will give you a prescription for pain medicine. Get it filled when ...

  2. Partial knee replacement - slideshow

    Science.gov (United States)

    ... medlineplus.gov/ency/presentations/100225.htm Partial knee replacement - series—Normal anatomy To use the sharing features ... M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited by ...

  3. Hip joint replacement - slideshow

    Science.gov (United States)

    ... medlineplus.gov/ency/presentations/100006.htm Hip joint replacement - series—Normal anatomy To use the sharing features ... M. Editorial team. Related MedlinePlus Health Topics Hip Replacement A.D.A.M., Inc. is accredited by ...

  4. Kidney Replacement Therapy

    Science.gov (United States)

    ... Size: A A A Listen En Español Kidney Replacement Therapy Diabetes sometimes damages kidneys so badly that ... Dialysis Dialysis, the more common form of kidney-replacement therapy, is a way of cleaning the blood ...

  5. Knee joint replacement - slideshow

    Science.gov (United States)

    ... medlineplus.gov/ency/presentations/100088.htm Knee joint replacement - series—Normal anatomy To use the sharing features ... M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited by ...

  6. Hip replacement - precautions

    Science.gov (United States)

    ... page, please enable JavaScript. After you have hip replacement surgery, you will need to be careful how ... to Expect at Home After you have hip replacement surgery, you will need to be careful how ...

  7. Hip replacement - discharge

    Science.gov (United States)

    ... discharge; Total hip replacement - discharge; Hip hemiarthroplasty - discharge; Osteoarthritis - hip replacement discharge ... such as downhill skiing or contact sports like football and soccer. But you should be able to ...

  8. Results of soy-based meal replacement formula on weight, anthropometry, serum lipids & blood pressure during a 40-week clinical weight loss trial

    Directory of Open Access Journals (Sweden)

    Heo Moonseong

    2003-11-01

    Full Text Available Abstract Background To evaluate the intermediate-term health outcomes associated with a soy-based meal replacement, and to compare the weight loss efficacy of two distinct patterns of caloric restriction. Methods Ninety overweight/obese (28 2 adults received a single session of dietary counseling and were randomized to either 12 weeks at 1200 kcal/day, 16 weeks at 1500 kcal/d and 12 weeks at 1800 kcal/d (i.e., the 12/15/18 diet group, or 28 weeks at 1500 kcal/d and 12 weeks at 1800 kcal/d (i.e., the 15/18 diet group. Weight, body fat, waist circumference, blood pressure and serum lipid concentrations were measured at 4-week intervals throughout the 40-week trial. Results Subjects in both treatments showed statistically significant improvements in outcomes. A regression model for weight change suggests that subjects with larger baseline weights tended to lose more weight and subjects in the 12/15/18 group tended to experience, on average, an additional 0.9 kg of weight loss compared with subjects in the 15/18 group. Conclusion Both treatments using the soy-based meal replacement program were associated with significant and comparable weight loss and improvements on selected health variables.

  9. Results of soy-based meal replacement formula on weight, anthropometry, serum lipids & blood pressure during a 40-week clinical weight loss trial

    Science.gov (United States)

    Fontaine, Kevin R; Yang, Dongyan; Gadbury, Gary L; Heshka, Stanley; Schwartz, Linda G; Murugesan, Radha; Kraker, Jennifer L; Heo, Moonseong; Heymsfield, Steven B; Allison, David B

    2003-01-01

    Background To evaluate the intermediate-term health outcomes associated with a soy-based meal replacement, and to compare the weight loss efficacy of two distinct patterns of caloric restriction. Methods Ninety overweight/obese (28 < BMI ≤ 41 kg/m2) adults received a single session of dietary counseling and were randomized to either 12 weeks at 1200 kcal/day, 16 weeks at 1500 kcal/d and 12 weeks at 1800 kcal/d (i.e., the 12/15/18 diet group), or 28 weeks at 1500 kcal/d and 12 weeks at 1800 kcal/d (i.e., the 15/18 diet group). Weight, body fat, waist circumference, blood pressure and serum lipid concentrations were measured at 4-week intervals throughout the 40-week trial. Results Subjects in both treatments showed statistically significant improvements in outcomes. A regression model for weight change suggests that subjects with larger baseline weights tended to lose more weight and subjects in the 12/15/18 group tended to experience, on average, an additional 0.9 kg of weight loss compared with subjects in the 15/18 group. Conclusion Both treatments using the soy-based meal replacement program were associated with significant and comparable weight loss and improvements on selected health variables. PMID:14624699

  10. Synthesis, Characterization, and Cross-Linking Strategy of a Quercetin-Based Epoxidized Monomer as a Naturally-Derived Replacement for BPA in Epoxy Resins.

    Science.gov (United States)

    Kristufek, Samantha L; Yang, Guozhen; Link, Lauren A; Rohde, Brian J; Robertson, Megan L; Wooley, Karen L

    2016-08-23

    The natural polyphenolic compound quercetin was functionalized and cross-linked to afford a robust epoxy network. Quercetin was selectively methylated and functionalized with glycidyl ether moieties using a microwave-assisted reaction on a gram scale to afford the desired monomer (Q). This quercetin-derived monomer was treated with nadic methyl anhydride (NMA) to obtain a cross-linked network (Q-NMA). The thermal and mechanical properties of this naturally derived network were compared to those of a conventional diglycidyl ether bisphenol A-derived counterpart (DGEBA-NMA). Q-NMA had similar thermal properties [i.e., glass transition (Tg ) and decomposition (Td ) temperatures] and comparable mechanical properties (i.e., Young's Modulus, storage modulus) to that of DGEBA-NMA. However, it had a lower tensile strength and higher flexural modulus at elevated temperatures. The application of naturally derived, sustainable compounds for the replacement of commercially available petrochemical-based epoxies is of great interest to reduce the environmental impact of these materials. Q-NMA is an attractive candidate for the replacement of bisphenol A-based epoxies in various specialty engineering applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Assessing ligand efficiencies using template-based molecular ...

    Indian Academy of Sciences (India)

    Keywords. TIBO; structure based drug design (SBDD); template; Tabu-clustering; HIV-1 reverse transcriptase (HIVRT); non-nucleoside reverse transcriptase inhibitor (NNRTI); pIC50; multiple linear regression (MLR); artificial neural network (ANN).

  12. Capital Equipment Replacement Decisions

    OpenAIRE

    Batterham, Robert L.; Fraser, K.I.

    1995-01-01

    This paper reviews the literature on the optimal replacement of capital equipment, especially farm machinery. It also considers the influence of taxation and capital rationing on replacement decisions. It concludes that special taxation provisions such as accelerated depreciation and investment allowances are unlikely to greatly influence farmers' capital equipment replacement decisions in Australia.

  13. TOTAL REPLACEMENT OF FISHMEAL WITH AN ORGANICALLY CERTIFIED YEAST–BASED PROTEIN IN PACIFIC WHITE SHRIMP (Litopenaeus Vannamei DIETS: LABORATORY AND FIELD TRIALS

    Directory of Open Access Journals (Sweden)

    Ewen McLean

    2006-04-01

    Full Text Available The feasibility of totally replacing the fishmeal component of marine shrimp (Litopenaeus vannamei diets was examined both in the laboratory setting and during a full–scale commercial trial. Animals were fed either a traditional fishmeal–based diet or one in which complete replacement of fishmeal, on a per protein basis, was manufactured using a yeast–based product, NuPro®. Laboratory studies determined that irrespective of diet fed, no difference in shrimp performance (weight gain, survival and SGR occurred. A field trial was thus activated to determine whether lab–scale studies were transferable to the commercial setting. Trials were conducted in earthen ponds from mid–June to early November 2005. Ponds were initially stocked with PL12–16 shrimp at a rate of 100,000 per hectare. At trial end, ponds receiving the NuPro®–based feed had equivalent growth to that of shrimp fed the traditional, fishmeal–based diet. Percent increase in weight from initial values and survival for the NuPro® ponds was 296, 269 and 275%, and 78, 76 and 85% respectively, whereas that for the fishmeal–based diet was 305% and 80% respectively. Noteworthy was that within pond size variation of L. vannamei was lower in NuPro® fed animals (±2.3 g when compared against animals receiving the traditional feed (±4.1 g. Overall observations from the field trial indicate the importance of the »bioreactor« pond with respect to the supply of energy to sustain shrimp growth potential.

  14. Bases biomoleculares do fotoenvelhecimento Molecular basis of photoaging

    Directory of Open Access Journals (Sweden)

    Suelen Montagner

    2009-07-01

    Full Text Available Com o aumento da expectativa de vida, o estudo do processo de envelhecimento orgânico tem sido estimulado. O envelhecimento da pele, órgão que espelha os sinais do tempo, é processo de deterioração progressiva, tempo-dependente, e pode ser intensificado pela exposição solar, então designado fotoenvelhecimento. O dano das radiações sobre diversas estruturas celulares e cutâneas leva a alterações morfológicas nesses componentes, fruto de modificações biomoleculares. Muitas pesquisas são desenvolvidas com o intuito de combater ou minimizar os efeitos do fotoenvelhecimento, porém a principal estratégia nesse sentido continua sendo a prevenção, só conseguida pelo progressivo desvendar dos mecanismos fisiopatogênicos envolvidos nesse processo.As a result of the increase in life expectancy, the study of the organic process of aging has been stimulated. Skin ageing, which reflects the signs of time, is a time-dependent process of progressive deterioration that can be intensified by sun exposure, which is known as photoaging. The damage of radiation on various cell structures and on the skin results in molecular and morphological changes to these components. Many research studies are performed to try to minimize the effects of photoaging; however, the main strategy to manage it is still prevention, which will only be achieved once we learn about the mechanisms involved in the process.

  15. Predictive value of semi-quantitative MRI-based scoring systems for future knee replacement: data from the osteoarthritis initiative

    Energy Technology Data Exchange (ETDEWEB)

    Hafezi-Nejad, Nima; Eng, John; Demehri, Shadpour [Johns Hopkins University School of Medicine, Musculoskeletal Radiology, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Zikria, Bashir [Johns Hopkins University, Department of Orthopedic Surgery, Baltimore, MD (United States); Carrino, John A. [Hospital for Special Surgery, Department of Radiology and Imaging, New York, NY (United States)

    2015-11-15

    To evaluate, in a confirmatory fashion, whether baseline and change from baseline to 24-month follow-up in cartilage damage, bone marrow lesions and meniscal damage are predictors of knee replacement (KR) in subjects with a high risk of osteoarthritis (OA), independent of the level of physical activity, symptom severity and radiographic abnormalities. Data from the Osteoarthritis Initiative's (OAI) baseline and 24-month follow-up knee MRIs of 115 patients (age range: 45-78 years; 48 % female; BMI: 20.9-48.7) were analyzed. Cartilage, bone marrow and menisci were semi-quantitatively scored according to the Whole-Organ Magnetic Resonance Imaging Score (WORMS) and Boston-Leeds Osteoarthritis Knee Score (BLOKS) systems in all compartments. Baseline and 24-month interval changes in structural tissue damage assessed by BLOKS and WORMS were used as predictors of KR independent of clinical and radiographic parameters using Cox hazard analysis. Adjustments were performed for age, gender, BMI and physical activity (Physical Activity Scale for the Elderly: PASE), Western Ontario and McMaster Questionnaire (WOMAC) total score and radiographic Kellgren-Lawrence (KL) score. BLOKS and WORMS baseline cartilage scores were predictors of KR independent of the PASE, WOMAC and KL score. One score increase in the average baseline BLOKS full-thickness cartilage defect score was associated with a [hazard ratio (95 % CI)] 13.55 (3.61-50.89) times greater risk of KR independent of the PASE, WOMAC and KL score. Net reclassification improvements (NRIs) of the additional evaluation of 24-month follow-up MRI scores and assessment of changes were not significant for prediction of KR (NRI range: - 7.23 - 24.8 %). The BLOKS cartilage score for full-thickness cartilage defects had the highest hazard for KR. Follow-up MRI changes in structural tissue damage, detected by BLOKS and WORMS cartilage, bone marrow or meniscus scores (up to 24 months) had no significant predictive value in addition

  16. A long-term evaluation of alternative treatments to replacement of resin-based composite restorations: results of a seven-year study.

    Science.gov (United States)

    Gordan, Valeria V; Garvan, Cynthia W; Blaser, Paul K; Mondragon, Eduardo; Mjör, Ivar A

    2009-12-01

    In a seven-year prospective cohort study, the authors assessed the longevity of defective resin-based composite (RBC) restorations that were not treated or were treated by means of repair, sealing, refinishing or total replacement. They also aimed to identify and quantify the main reasons clinicians diagnosed restorations as defective. Thirty-seven patients--19 women and 18 men--who were aged 27 through 78 years (mean = 57 years, standard deviation [SD] = 13 years) and had a total of 88 defective restorations participated in the study. Two of the authors assigned each restoration to one of five treatment groups, depending on the patient's treatment need: repair (n = 25), sealing of defective margins (n = 12), refinishing (n = 19), replacement (n = 16) and no treatment (n = 16). The authors conducted a survival analysis (according to modified U.S. Public Health Service criteria) at baseline and again at six months, one year, two years and seven years after treatment. The authors determined that the main reasons clinicians diagnosed the 88 restorations as being defective were marginal discoloration (n = 53, 60.2 percent), marginal degradation (n = 18, 20.5 percent) and color mismatch (n = 17, 19.3 percent). The authors examined 69 (78 percent) restorations at six months, 68 (77 percent) after one year, 62 (70 percent) after two years and 53 after seven years (60 percent). The percentages of failed restorations for each treatment after seven years were 0 percent for repair, 0 percent for sealing of defective margins, 18 percent for refinishing, 21 percent for replacement and 23 percent for no treatment. The P value for the log-rank test of equality for these groups was .36. Restorations degraded to varying degrees in all criteria, and the survival of restorations differed among treatment approaches. Longitudinal data collected across seven years support the viability of all nonreplacement restoration treatment strategies.

  17. The replacement of touch-terminal consoles of the CERN antiproton accumulator complex (AAC) by office PC's as well as X-windows based workstations

    International Nuclear Information System (INIS)

    Chohan, V.; Deloose, I.; Shering, G.

    1992-01-01

    With aging hardware and expensive maintenance and replacement possibilities, it was decided to upgrade the AAC touch terminal consoles with modern hardware. With significant amount of operational application software developed with touch terminals over 10 years, the philosophy adopted was to attempt a total emulation of these console functions of touch actions, graphics display as well as simple keyboard terminal entry onto the front-end computer controlling the AAC. The PC based emulation by mouse and multiple windows under MS-DOS and later, under the Windows 3 environment was realized relatively quickly; the next stage was therefore to do the same on the Unix platform using software based on X-windows. The communications channel was established using the TCP/IP socket library. This paper reviews this work up to the operational implementation for routine control room usage for both these solutions. (author)

  18. Three decades of structure- and property-based molecular design

    DEFF Research Database (Denmark)

    Müller, Klaus

    2014-01-01

    of bioinformatics. It describes the strategic shift to large compound libraries and high-throughput screening with the development of novel compound storage and ultra-high-throughput screening facilities, as well as the strategic return to focused screening of small motif-based compound libraries...

  19. Cadmium plating replacements

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, M.J.; Groshart, E.C.

    1995-03-01

    The Boeing Company has been searching for replacements to cadmium plate. Two alloy plating systems seem close to meeting the needs of a cadmium replacement. The two alloys, zinc-nickel and tin-zinc are from alloy plating baths; both baths are neutral pH. The alloys meet the requirements for salt fog corrosion resistance, and both alloys excel as a paint base. Currently, tests are being performed on standard fasteners to compare zinc-nickel and tin-zinc on threaded hardware where cadmium is heavily used. The Hydrogen embrittlement propensity of the zinc-nickel bath has been tested, and just beginning for the tin-zinc bath. Another area of interest is the electrical properties on aluminum for tin-zinc and will be discussed. The zinc-nickel alloy plating bath is in production in Boeing Commercial Airplane Group for non-critical low strength steels. The outlook is promising that these two coatings will help The Boeing Company significantly reduce its dependence on cadmium plating.

  20. Foraging on the potential energy surface: a swarm intelligence-based optimizer for molecular geometry.

    Science.gov (United States)

    Wehmeyer, Christoph; Falk von Rudorff, Guido; Wolf, Sebastian; Kabbe, Gabriel; Schärf, Daniel; Kühne, Thomas D; Sebastiani, Daniel

    2012-11-21

    We present a stochastic, swarm intelligence-based optimization algorithm for the prediction of global minima on potential energy surfaces of molecular cluster structures. Our optimization approach is a modification of the artificial bee colony (ABC) algorithm which is inspired by the foraging behavior of honey bees. We apply our modified ABC algorithm to the problem of global geometry optimization of molecular cluster structures and show its performance for clusters with 2-57 particles and different interatomic interaction potentials.

  1. Integrative pathway knowledge bases as a tool for systems molecular medicine.

    Science.gov (United States)

    Liang, Mingyu

    2007-08-20

    There exists a sense of urgency to begin to generate a cohesive assembly of biomedical knowledge as the pace of knowledge accumulation accelerates. The urgency is in part driven by the emergence of systems molecular medicine that emphasizes the combination of systems analysis and molecular dissection in the future of medical practice and research. A potentially powerful approach is to build integrative pathway knowledge bases that link organ systems function with molecules.

  2. Rapid Prototyping of Chemical Microsensors Based on Molecularly Imprinted Polymers Synthesized by Two-Photon Stereolithography.

    Science.gov (United States)

    Gomez, Laura Piedad Chia; Spangenberg, Arnaud; Ton, Xuan-Anh; Fuchs, Yannick; Bokeloh, Frank; Malval, Jean-Pierre; Tse Sum Bui, Bernadette; Thuau, Damien; Ayela, Cédric; Haupt, Karsten; Soppera, Olivier

    2016-07-01

    Two-photon stereolithography is used for rapid prototyping of submicrometre molecularly imprinted polymer-based 3D structures. The structures are evaluated as chemical sensing elements and their specific recognition properties for target molecules are confirmed. The 3D design capability is exploited and highlighted through the fabrication of an all-organic molecularly imprinted polymeric microelectromechanical sensor. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. CRISPR/Cas9 and active genetics-based trans-species replacement of the endogenousDrosophila kni-L2 CRM reveals unexpected complexity.

    Science.gov (United States)

    Xu, Xiang-Ru Shannon; Gantz, Valentino Matteo; Siomava, Natalia; Bier, Ethan

    2017-12-23

    The knirps ( kni ) locus encodes transcription factors required for induction of the L2 wing vein in Drosophila . Here, we employ diverse CRISPR/Cas9 genome editing tools to generate a series of targeted lesions within the endogenous cis-regulatory module (CRM) required for kni expression in the L2 vein primordium. Phenotypic analysis of these ' in locus ' mutations based on both expression of Kni protein and adult wing phenotypes, reveals novel unexpected features of L2-CRM function including evidence for a chromosome pairing-dependent process that promotes transcription. We also demonstrate that self-propagating active genetic elements (CopyCat elements) can efficiently delete and replace the L2-CRM with orthologous sequences from other divergent fly species. Wing vein phenotypes resulting from these trans-species enhancer replacements parallel features of the respective donor fly species. This highly sensitive phenotypic readout of enhancer function in a native genomic context reveals novel features of CRM function undetected by traditional reporter gene analysis. © 2017, Xu et al.

  4. New polynomial-based molecular descriptors with low degeneracy.

    Directory of Open Access Journals (Sweden)

    Matthias Dehmer

    Full Text Available In this paper, we introduce a novel graph polynomial called the 'information polynomial' of a graph. This graph polynomial can be derived by using a probability distribution of the vertex set. By using the zeros of the obtained polynomial, we additionally define some novel spectral descriptors. Compared with those based on computing the ordinary characteristic polynomial of a graph, we perform a numerical study using real chemical databases. We obtain that the novel descriptors do have a high discrimination power.

  5. Replacement policies for dairy cows

    DEFF Research Database (Denmark)

    Nielsen, Lars Relund; Kristensen, Anders Ringgaard

    2010-01-01

    In a recent paper a hierarchical Markov decision processes (MDP) with finite state and action space was formulated for the dairy cow replacement problem with stage lengths of 1 d. Bayesian updating was used to predict the performance of each cow in the herd and economic decisions were based...... on the prediction. The model can be used to assist the farmer in replacement decisions on a daily basis and is based on daily milk yield measurements that are available in modern milking systems. This talk will present the results of the paper and discuss directions for further research....

  6. Molecular monolayers for electrical passivation and functionalization of silicon-based solar energy devices

    NARCIS (Netherlands)

    Veerbeek, Janneke; Firet, Nienke J.; Vijselaar, Wouter; Elbersen, R.; Gardeniers, Han; Huskens, Jurriaan

    2017-01-01

    Silicon-based solar fuel devices require passivation for optimal performance yet at the same time need functionalization with (photo)catalysts for efficient solar fuel production. Here, we use molecular monolayers to enable electrical passivation and simultaneous functionalization of silicon-based

  7. Molecular variability of oat based on gene specific markers

    Directory of Open Access Journals (Sweden)

    Želmíra Balážová

    2017-01-01

    Full Text Available Microsoft Office User 14.00 Oat (Avena sativa L. is a grass planted as a cereal crop. Cultivation of oat is increasing in the recent years because of its good nutrition value. The aim of our study was to analyze genetic variability of oat accessions based on SCoT markers. Eighteen primers were used to study polymorfism of 8 oat genotypes. All 18 primers produced polymorphic and reproducible data. Altogether 153 different fragments were amplified of which 67 were polymorphic with an average number of 3.72 polymorphic fragments per genotype. The number of polymorphic fragments ranged from one (SCoT9, SCoT62 to nine (SCoT40. The percentage of polymorphic bands ranged from 14.29% (SCoT9 to 60% (SCoT59 with an average of 41.62%. Genetic polymorphism was characterized based on diversity index (DI, probability of identity (PI and polymorphic information content (PIC. The diversity index of the tested SCoT markers ranged from 0 (SCoT9, SCoT62 to 0.878 (SCoT40 with an average of 0.574. The polymorphic information content ranged from 0 (SCoT9, SCoT62 to 0.876 (SCoT40 with an average of 0.524. Dendrogram based on hierarchical cluster analysis using UPGMA algorithm grouped genotypes into two main clusters. Two genotypes, Taiko and Vok were genetically the closest. Results showed the utility of SCoT markers for estimation of genetic diversity of oat genotypes leading to genotype identification.  Normal 0 21 false false false EN-GB X-NONE X-NONE

  8. Efficacy of a meal replacement diet plan compared to a food-based diet plan after a period of weight loss and weight maintenance: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Hutchisen Tammy

    2010-03-01

    Full Text Available Abstract Background Obesity has reached epidemic proportions in the United States. It is implicated in the development of a variety of chronic disease states and is associated with increased levels of inflammation and oxidative stress. The objective of this study is to examine the effect of Medifast's meal replacement program (MD on body weight, body composition, and biomarkers of inflammation and oxidative stress among obese individuals following a period of weight loss and weight maintenance compared to a an isocaloric, food-based diet (FB. Methods This 40-week randomized, controlled clinical trial included 90 obese adults with a body mass index (BMI between 30 and 50 kg/m2, randomly assigned to one of two weight loss programs for 16 weeks and then followed for a 24-week period of weight maintenance. The dietary interventions consisted of Medifast's meal replacement program for weight loss and weight maintenance, or a self-selected, isocaloric, food-based meal plan. Results Weight loss at 16 weeks was significantly better in the Medifast group (MD versus the food-based group (FB (12.3% vs. 6.9%, and while significantly more weight was regained during weight maintenance on MD versus FB, overall greater weight loss was achieved on MD versus FB. Significantly more of the MD participants lost ≥ 5% of their initial weight at week 16 (93% vs. 55% and week 40 (62% vs. 30%. There was no difference in satiety observed between the two groups during the weight loss phase. Significant improvements in body composition were also observed in MD participants compared to FB at week 16 and week 40. At week 40, both groups experienced improvements in biochemical outcomes and other clinical indicators. Conclusions Our data suggest that the meal replacement diet plan evaluated was an effective strategy for producing robust initial weight loss and for achieving improvements in a number of health-related parameters during weight maintenance, including inflammation

  9. Modulating the pH-activity profile of cellulase by substitution: replacing the general base catalyst aspartate with cysteinesulfinate in cellulase A from Cellulomonas fimi.

    Science.gov (United States)

    Cockburn, Darrell W; Vandenende, Chris; Clarke, Anthony J

    2010-03-09

    Cellulase A (CenA) from Cellulomonas fimi is an inverting glycoside hydrolase and a member of family 6 of the CAZy database classification system. We replaced its putative catalytic base aspartyl residues, Aps392 and Asp216, with cysteinesulfinate using a combination of site-directed mutagenesis and chemical modification to investigate the applicability of this approach for the modulation of enzymatic properties. The substituted cysteinyl residues were oxidized to cysteinesulfinic acid with hydrogen peroxide, and the resulting protein products were demonstrated to retain their native structure. Oxidation of the Asp392Cys mutant enzyme restored 52% of wild-type activity when assessed at pH 7.5, whereas Asp216Cys CenA remained inactive. This suggests that Asp216 is not the catalytic base and provides further support for Asp392 performing this role. Similar substitution of the catalytic acid residue Asp252 or the catalytic nucleophile of the retaining enzyme Cel5A from Thermobifida fusca failed to produce active enzymes. This indicates a potential utility of this approach for uniquely identifying catalytic base residues. The replacement of Asp392 with cysteinesulfinate induced an acidic shift in the pH profile of the enzyme such that this enzyme derivative was more active than wild-type CenA below pH 5.5. These data demonstrate the potential of combining site-directed mutagenesis with chemical modification as a viable approach for the modulation of cellulases, and potentially other glycoside hydrolases, at low pH.

  10. Could nutritional rehabilitation at home complement or replace centre-based therapeutic feeding programmes for severe malnutrition?

    Science.gov (United States)

    Gaboulaud, V; Dan-Bouzoua, N; Brasher, C; Fedida, G; Gergonne, B; Brown, V

    2007-02-01

    To measure the success rate of three different strategies used in Médecins Sans Frontières large-scale therapeutic nutritional rehabilitation programme in Niger, we analysed three cohorts of severely malnourished patients in terms of daily weight gain, length of stay, recovery, case fatality and defaulting. A total of 1937 children aged 6-59 months were followed prospectively from 15 August 2002 to 21 October 2003. For the three cohorts, 660 children were maintained in the therapeutic feeding centre (TFC) during the entire treatment, 937 children were initially treated at the TFC and completed treatment at home and 340 children were exclusively treated at home. For all cohorts, average time in the programme and average weight gain met the international standards (30-40 days, >8 g/kg/day). Default rates were 28.1, 16.8 and 5.6% for TFC only, TFC plus home-based and home-based alone strategies, respectively. The overall case fatality rate for the entire programme was 6.8%. Case fatality rates were 18.9% for TFC only and 1.7% for home-based alone. No deaths were recorded in children transferred to rehabilitation at home. This study suggests that satisfactory results for the treatment of severe malnutrition can be achieved using a combination of home and hospital-based strategies.

  11. Can face-to-face patient education be replaced by computer-based patient education? A randomised trial.

    NARCIS (Netherlands)

    Keulers, B.J.; Welters, C.F.; Spauwen, P.H.M.; Houpt, P.

    2007-01-01

    OBJECTIVE: Computer-based patient education is an effective (therapeutic) tool. More and more studies prove that it can be an effective additive for face-to-face education, but it is still unclear if it is possible to educate patients by only using a computer. Our objective was to compare knowledge

  12. [Molecular identification in genus of Lilium based on DNA barcoding].

    Science.gov (United States)

    Zheng, Si-Hao; Li, Ya-Kang; Ren, Wei-Guang; Huang, Lin-Fang

    2014-12-01

    To establish a new method for identifying genus of Lilium by DNA barcoding technology, ITS, ITS2, psbA-trnH, matK and rbcL sequences were analyzed in term of variation of inter- and intra-species, barcoding gap, neighbor-joining tree to distinguish genus of Lilium based on 978 sequences from experimental and GenBank database, and identification efficiency was evaluated by Nearest distance and BLAST1 methods. The results showed that DNA barcoding could identify different species in genus of Lilium. ITS sequence performed higher identification efficiency, and had significant difference between intra- and inter-species. And NJ tree could also divide species into different clades. Results indicate that DNA barcoding can identify genus of Lilium accurately. ITS sequence can be the optimal barcode to identify species of Lilium.

  13. Singlet oxygen-based electrosensing by molecular photosensitizers

    Science.gov (United States)

    Trashin, Stanislav; Rahemi, Vanoushe; Ramji, Karpagavalli; Neven, Liselotte; Gorun, Sergiu M.; de Wael, Karolien

    2017-07-01

    Enzyme-based electrochemical biosensors are an inspiration for the development of (bio)analytical techniques. However, the instability and reproducibility of the reactivity of enzymes, combined with the need for chemical reagents for sensing remain challenges for the construction of useful devices. Here we present a sensing strategy inspired by the advantages of enzymes and photoelectrochemical sensing, namely the integration of aerobic photocatalysis and electrochemical analysis. The photosensitizer, a bioinspired perfluorinated Zn phthalocyanine, generates singlet-oxygen from air under visible light illumination and oxidizes analytes, yielding electrochemically-detectable products while resisting the oxidizing species it produces. Compared with enzymatic detection methods, the proposed strategy uses air instead of internally added reactive reagents, features intrinsic baseline correction via on/off light switching and shows C-F bonds-type enhanced stability. It also affords selectivity imparted by the catalytic process and nano-level detection, such as 20 nM amoxicillin in μl sample volumes.

  14. Effect of molecular packing on corannulene-based materials electroluminescence.

    Science.gov (United States)

    Zoppi, Laura; Martin-Samos, Layla; Baldridge, Kim K

    2011-09-07

    The present investigation reports for the first time a detailed theoretical analysis of the optical absorption spectra of corannulene-based materials using state-of-the-art first-principles many-body GW-BSE theory. The study specifically addresses the nature of optical excitations for predictions regarding suitability for device fabrication. The well-defined structure-correlation relationship in functionalized corannulenes is used in a focused investigation of the predicted optoelectronic properties in both the isolated state and bulk crystals. The findings suggest that the excitonic properties are strongly dependent on the specific substituent group as well as the crystalline arrangement. Arylethynyl-substituted corannulene derivatives are shown to be the most suitable for device purposes.

  15. Soybean domestication: the origin, genetic architecture and molecular bases.

    Science.gov (United States)

    Sedivy, Eric J; Wu, Faqiang; Hanzawa, Yoshie

    2017-04-01

    Domestication provides an important model for the study of evolution, and information learned from domestication research aids in the continued improvement of crop species. Recent progress in de novo assembly and whole-genome resequencing of wild and cultivated soybean genomes, in addition to new archeological discoveries, sheds light on the origin of this important crop and provides a clearer view on the modes of artificial selection that drove soybean domestication and diversification. This novel genomic information enables the search for polymorphisms that underlie variation in agronomic traits and highlights genes that exhibit a signature of selection, leading to the identification of a number of candidate genes that may have played important roles in soybean domestication, diversification and improvement. These discoveries provide a novel point of comparison on the evolutionary bases of important agronomic traits among different crop species. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  16. Optimization on replacement period of plant equipment

    International Nuclear Information System (INIS)

    Kasai, Masao; Asano, Hiromi

    2002-01-01

    Optimization of the replacement period of plant equipment is one of the main items to rationalize the activities on plant maintenance. There are several models to replace the equipment and the formulations for optimizing the replacement period are different among these models. In this study, we calculated the optimum replacement periods for some equipment parts based on the replacement models and found that the optimum solutions are not so largely differ from the replacement models as far as the replacement period is not so large. So we will be able to use the most usable model especially in the early phase of rationalization on plant maintenance, since there are large uncertainties in data for optimization. (author)

  17. Large resistance change on magnetic tunnel junction based molecular spintronics devices

    Science.gov (United States)

    Tyagi, Pawan; Friebe, Edward

    2018-05-01

    Molecular bridges covalently bonded to two ferromagnetic electrodes can transform ferromagnetic materials and produce intriguing spin transport characteristics. This paper discusses the impact of molecule induced strong coupling on the spin transport. To study molecular coupling effect the octametallic molecular cluster (OMC) was bridged between two ferromagnetic electrodes of a magnetic tunnel junction (Ta/Co/NiFe/AlOx/NiFe/Ta) along the exposed side edges. OMCs induced strong inter-ferromagnetic electrode coupling to yield drastic changes in transport properties of the magnetic tunnel junction testbed at the room temperature. These OMCs also transformed the magnetic properties of magnetic tunnel junctions. SQUID and ferromagnetic resonance studies provided insightful data to explain transport studies on the magnetic tunnel junction based molecular spintronics devices.

  18. Gd-based macromolecules and nanoparticles as magnetic resonance contrast agents for molecular imaging.

    Science.gov (United States)

    Huang, Ching-Hui; Tsourkas, Andrew

    2013-01-01

    As we move towards an era of personalized medicine, molecular imaging contrast agents are likely to see an increasing presence in routine clinical practice. Magnetic resonance (MR) imaging has garnered particular interest as a platform for molecular imaging applications due its ability to monitor anatomical changes concomitant with physiologic and molecular changes. One promising new direction in the development of MR contrast agents involves the labeling and/or loading of nanoparticles with gadolinium (Gd). These nanoplatforms are capable of carrying large payloads of Gd, thus providing the requisite sensitivity to detect molecular signatures within disease pathologies. In this review, we discuss some of the progress that has recently been made in the development of Gd-based macromolecules and nanoparticles and outline some of the physical and chemical properties that will be important to incorporate into the next generation of contrast agents, including high Gd chelate stability, high "relaxivity per particle" and "relaxivity density", and biodegradability.

  19. Parallel assessment of the impact of different hormone replacement therapies on breast density by radiologist-and computer-based analyses of mammograms

    DEFF Research Database (Denmark)

    Pettersen, P.C.; Raundahl, Jakob; Loog, M.

    2008-01-01

    , randomized, placebo-controlled trials formed the basis of the present post hoc analysis. Active treatments were 1 mg estradiol continuously combined with 0.125 mg trimegestone (oral hormone replacement therapy, HRT) or low-dose (150 or 300 microg estradiol) nasal estradiol cyclically combined with 200 mg...... micronized progesterone (nasal HRT). The effects on breast density were assessed by a radiologist, providing the BI-RADS score and the interactive threshold, and by a computer-based approach, providing the measure of stripiness and the HRT-effect specific measure of breast density. RESULTS: In the oral HRT...... trial, active treatment induced a significant increase in breast density, which was consistent in all methods used (all p 0.05). In contrast, none of the methods detected significant changes in women receiving nasal HRT. The sensitivity of automated methods to discriminate HRT- from placebo...

  20. Molecular Phylogenetic: Organism Taxonomy Method Based on Evolution History

    Directory of Open Access Journals (Sweden)

    N.L.P Indi Dharmayanti

    2011-03-01

    Full Text Available Phylogenetic is described as taxonomy classification of an organism based on its evolution history namely its phylogeny and as a part of systematic science that has objective to determine phylogeny of organism according to its characteristic. Phylogenetic analysis from amino acid and protein usually became important area in sequence analysis. Phylogenetic analysis can be used to follow the rapid change of a species such as virus. The phylogenetic evolution tree is a two dimensional of a species graphic that shows relationship among organisms or particularly among their gene sequences. The sequence separation are referred as taxa (singular taxon that is defined as phylogenetically distinct units on the tree. The tree consists of outer branches or leaves that represents taxa and nodes and branch represent correlation among taxa. When the nucleotide sequence from two different organism are similar, they were inferred to be descended from common ancestor. There were three methods which were used in phylogenetic, namely (1 Maximum parsimony, (2 Distance, and (3 Maximum likehoood. Those methods generally are applied to construct the evolutionary tree or the best tree for determine sequence variation in group. Every method is usually used for different analysis and data.

  1. Molecular MRI based on hyper-polarized xenon

    International Nuclear Information System (INIS)

    Tassali, Nawal

    2012-01-01

    Magnetic Resonance Imaging (MRI) has a high importance in medicine as it enables the observation of the organs inside the body without the use of radiative or invasive techniques. However it is known to suffer from poor sensitivity. To circumvent this limitation, a key solution resides in the use of hyper-polarized species. Among the entities with which we can drastically increase nuclear polarization, xenon has very specific properties through its interactions with its close environment that lead to a wide chemical shift bandwidth. The goal is thus to use it as a tracer. This PhD thesis focuses on the concept of 129 Xe MRI-based sensors for the detection of biological events. In this approach, hyper-polarized xenon is vectorized to biological targets via functionalized host systems, and then localized thanks to fast dedicated MRI sequences. The conception and set-up of a spin-exchange optical pumping device is first described. Then studies about the interaction of the hyper-polarized noble gas with new cryptophanes susceptible to constitute powerful host molecules are detailed. Also the implementation of recent MRI sequences optimized for the transient character of the hyper-polarization and taking profit of the xenon in-out exchange is described. Applications of this approach for the detection of metallic ions and cellular receptors are studied. Finally, our first in vivo results on a small animal model are presented. (author) [fr

  2. Detecting Molecular Properties by Various Laser-Based Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Hsin, Tse-Ming [Iowa State Univ., Ames, IA (United States)

    2007-01-01

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

  3. Impact assessment of biomass-based district heating systems in densely populated communities. Part II: Would the replacement of fossil fuels improve ambient air quality and human health?

    Science.gov (United States)

    Petrov, Olga; Bi, Xiaotao; Lau, Anthony

    2017-07-01

    To determine if replacing fossil fuel combustion with biomass gasification would impact air quality, we evaluated the impact of a small-scale biomass gasification plant (BRDF) at a university campus over 5 scenarios. The overall incremental contribution of fine particles (PM2.5) is found to be at least one order of magnitude lower than the provincial air quality objectives. The maximum PM2.5 emission from the natural gas fueled power house (PH) could adversely add to the already high background concentration levels. Nitrogen dioxide (NO2) emissions from the BRDF with no engineered pollution controls for NOx in place exceeded the provincial objective in all seasons except during summer. The impact score, IS, was the highest for NO2 (677 Disability Adjusted Life Years, DALY) when biomass entirely replaced fossil fuels, and the highest for PM2.5 (64 DALY) and CO (3 DALY) if all energy was produced by natural gas at PH. Complete replacement of fossil fuels by one biomass plant can result in almost 28% higher health impacts (708 DALY) compared to 513 DALY when both the current BRDF and the PH are operational mostly due to uncontrolled NO2 emissions. Observations from this study inform academic community, city planners, policy makers and technology developers on the impacts of community district heating systems and possible mitigation strategies: a) community energy demand could be met either by splitting emissions into more than one source at different locations and different fuel types or by a single source with the least-impact-based location selection criteria with biomass as a fuel; b) advanced high-efficiency pollution control devices are essential to lower emissions for emission sources located in a densely populated community; c) a spatial and temporal impact assessment should be performed in developing bioenergy-based district heating systems, in which the capital and operational costs should be balanced with not only the benefit to greenhouse gas emission

  4. Intra-tumor heterogeneity in breast cancer has limited impact on transcriptomic-based molecular profiling.

    Science.gov (United States)

    Karthik, Govindasamy-Muralidharan; Rantalainen, Mattias; Stålhammar, Gustav; Lövrot, John; Ullah, Ikram; Alkodsi, Amjad; Ma, Ran; Wedlund, Lena; Lindberg, Johan; Frisell, Jan; Bergh, Jonas; Hartman, Johan

    2017-11-29

    Transcriptomic profiling of breast tumors provides opportunity for subtyping and molecular-based patient stratification. In diagnostic applications the specimen profiled should be representative of the expression profile of the whole tumor and ideally capture properties of the most aggressive part of the tumor. However, breast cancers commonly exhibit intra-tumor heterogeneity at molecular, genomic and in phenotypic level, which can arise during tumor evolution. Currently it is not established to what extent a random sampling approach may influence molecular breast cancer diagnostics. In this study we applied RNA-sequencing to quantify gene expression in 43 pieces (2-5 pieces per tumor) from 12 breast tumors (Cohort 1). We determined molecular subtype and transcriptomic grade for all tumor pieces and analysed to what extent pieces originating from the same tumors are concordant or discordant with each other. Additionally, we validated our finding in an independent cohort consisting of 19 pieces (2-6 pieces per tumor) from 6 breast tumors (Cohort 2) profiled using microarray technique. Exome sequencing was also performed on this cohort, to investigate the extent of intra-tumor genomic heterogeneity versus the intra-tumor molecular subtype classifications. Molecular subtyping was consistent in 11 out of 12 tumors and transcriptomic grade assignments were consistent in 11 out of 12 tumors as well. Molecular subtype predictions revealed consistent subtypes in four out of six patients in this cohort 2. Interestingly, we observed extensive intra-tumor genomic heterogeneity in these tumor pieces but not in their molecular subtype classifications. Our results suggest that macroscopic intra-tumoral transcriptomic heterogeneity is limited and unlikely to have an impact on molecular diagnostics for most patients.

  5. Video-based instructions for surgical hand disinfection as a replacement for conventional tuition? A randomised, blind comparative study

    Directory of Open Access Journals (Sweden)

    Weber, Uwe

    2016-08-01

    Full Text Available Introduction: Various different learning methods are available for planning tuition regarding the introduction to surgical hand disinfection. These learning methods should help to organise and deal with this topic. The use of a video film is an alternative to conventional tuition due to the real presentation possibilities of practical demonstration. Objective: This study examines by way of comparison which form of communication is more effective for learning and applying surgical hand disinfection for medical students in their first year of studies: video-based instruction or conventional tuition. Methodology: A total of 50 first-year medical students were randomly allocated either to the “Conventional Instruction” (CI study group or to the “Video-based Instruction” (VI study group. The conventional instruction was carried out by an experienced nurse preceptor/nurse educator for the operating theatre who taught the preparatory measures and the actual procedure in a two-minute lesson. The second group watched a two-minute video sequence with identical content. Afterwards, both groups demonstrated practically the knowledge they had acquired at an individual practical test station. The quality (a of the preparation and (b of the procedure as well as (c the quality of the results was assessed by 6 blind experts using a check list. The acceptability of the respective teaching method was also asked about using a questionnaire.Results: The group performance did not differ either in the preparation (=-78, <0.44 or in the quality (=-99, <0.34. With respect to performance, it was possible to demonstrate a strong treatment effect. In the practical (=-3.33, <0.002, =0.943 and in the total score (=-2.65, <0.011, =0.751, the group with video-based instruction achieved a significantly better result. In response to the question as to which of the two learning methods they would prefer, the significant majority (60.4% of students stated video instruction

  6. Biomedical wellness monitoring system based upon molecular markers

    Science.gov (United States)

    Ingram, Whitney

    2012-06-01

    We wish to assist caretakers with a sensor monitoring systems for tracking the physiological changes of homealone patients. One goal is seeking biomarkers and modern imaging sensors like stochastic optical reconstruction microscopy (STORM), which has achieved visible imaging at the nano-scale range. Imaging techniques like STORM can be combined with a fluorescent functional marker in a system to capture the early transformation signs from wellness to illness. By exploiting both microscopic knowledge of genetic pre-disposition and the macroscopic influence of epigenetic factors we hope to target these changes remotely. We adopt dual spectral infrared imaging for blind source separation (BSS) to detect angiogenesis changes and use laser speckle imaging for hypertension blood flow monitoring. Our design hypothesis for the monitoring system is guided by the user-friendly, veteran-preferred "4-Non" principles (noninvasive, non-contact, non-tethered, non-stop-to-measure) and by the NIH's "4Ps" initiatives (predictive, personalized, preemptive, and participatory). We augment the potential storage system with the recent know-how of video Compressive Sampling (CSp) from surveillance cameras. In CSp only major changes are saved, which reduces the manpower cost of caretakers and medical analysts. This CSp algorithm is based on smart associative memory (AM) matrix storage: change features and detailed scenes are written by the outer-product and read by the inner product without the usual Harsh index for image searching. From this approach, we attempt to design an effective household monitoring approach to save healthcare costs and maintain the quality of life of seniors.

  7. A parallel row-based algorithm with error control for standard-cell replacement on a hypercube multiprocessor

    Science.gov (United States)

    Sargent, Jeff Scott

    1988-01-01

    A new row-based parallel algorithm for standard-cell placement targeted for execution on a hypercube multiprocessor is presented. Key features of this implementation include a dynamic simulated-annealing schedule, row-partitioning of the VLSI chip image, and two novel new approaches to controlling error in parallel cell-placement algorithms; Heuristic Cell-Coloring and Adaptive (Parallel Move) Sequence Control. Heuristic Cell-Coloring identifies sets of noninteracting cells that can be moved repeatedly, and in parallel, with no buildup of error in the placement cost. Adaptive Sequence Control allows multiple parallel cell moves to take place between global cell-position updates. This feedback mechanism is based on an error bound derived analytically from the traditional annealing move-acceptance profile. Placement results are presented for real industry circuits and the performance is summarized of an implementation on the Intel iPSC/2 Hypercube. The runtime of this algorithm is 5 to 16 times faster than a previous program developed for the Hypercube, while producing equivalent quality placement. An integrated place and route program for the Intel iPSC/2 Hypercube is currently being developed.

  8. Molecular property investigations of an ortho-hydroxy Schiff base type compound with the first-principle molecular dynamics approach.

    Science.gov (United States)

    Jezierska-Mazzarello, Aneta; Vuilleumier, Rodolphe; Panek, Jarosław J; Ciccotti, Giovanni

    2010-01-14

    The structure, proton transfer, and vibrational dynamics under ambient conditions of a selected ortho-hydroxy Schiff base type compound, 2-(N-methyl-alpha-iminoethyl)-4-chlorophenol, containing a very short intramolecular hydrogen bond, were investigated computationally in the gas phase and in the crystal by density functional theory (DFT) based first-principle molecular dynamics (FPMD). It is found that the proton is well localized on the nitrogen side of the O...H...N bridge in the crystal phase, in agreement with X-ray diffraction experiments, while a more labile proton is located most of the time on the oxygen side in a vacuum. Environmental effects on this very strong hydrogen bond thus appear crucial and lead to drastic changes of the infrared (IR) spectrum: The computed gas-phase IR spectrum shows a very broad absorption band that covers frequencies from about 1000 to 3000 cm(-1) assigned to the labile proton. In mere contrast, a much more localized absorption band around 2600-2700 cm(-1) is predicted in the crystal phase. Finally, effects of the quantization of the proton motion on the hydrogen bond structure were estimated in two ways. First, we constructed the one-dimensional (1D) potential energy surface (PES) for the proton along the O...H...N bridge in a vacuum. The 1D Schrodinger equation was then solved. Next, path integral molecular dynamics (PIMD) was performed in the solid state. Inclusion of quantum effects does not affect the observed change of the most probable tautomer, upon going from the gas phase to the crystal.

  9. Spin-polarized transport properties of a pyridinium-based molecular spintronics device

    Science.gov (United States)

    Zhang, J.; Xu, B.; Qin, Z.

    2018-05-01

    By applying a first-principles approach based on non-equilibrium Green's functions combined with density functional theory, the transport properties of a pyridinium-based "radical-π-radical" molecular spintronics device are investigated. The obvious negative differential resistance (NDR) and spin current polarization (SCP) effect, and abnormal magnetoresistance (MR) are obtained. Orbital reconstruction is responsible for novel transport properties such as that the MR increases with bias and then decreases and that the NDR being present for both parallel and antiparallel magnetization configurations, which may have future applications in the field of molecular spintronics.

  10. Wastewater reuse in a cascade based system of a petrochemical industry for the replacement of losses in cooling towers.

    Science.gov (United States)

    Hansen, Everton; Rodrigues, Marco Antônio Siqueira; Aquim, Patrice Monteiro de

    2016-10-01

    This article discusses the mapping of opportunities for the water reuse in a cascade based system in a petrochemical industry in southern Brazil. This industrial sector has a large demand for water for its operation. In the studied industry, for example, approximately 24 million cubic meters of water were collected directly from the source in 2014. The objective of this study was to evaluate the implementation of the reuse of water in cascade in a petrochemical industry, focusing on the reuse of aqueous streams to replenish losses in the cooling towers. This is an industrial scale case study with real data collected during the years 2014 and 2015. Water reuse was performed using heuristic approach based on the exploitation of knowledge acquired during the search process. The methodology of work consisted of the construction of a process map identifying the stages of production and water consumption, as well as the characterization of the aqueous streams involved in the process. For the application of the industrial water reuse as cooling water, mass balances were carried out considering the maximum concentration levels of turbidity, pH, conductivity, alkalinity, calcium hardness, chlorides, sulfates, silica, chemical oxygen demand and suspended solids as parameters turbidity, pH, conductivity, alkalinity, calcium hardness, chlorides, sulfates, silica, chemical oxygen demand and suspended solids as parameters. The adopted guideline was the fulfillment of the water quality criteria for each application in the industrial process. The study showed the feasibility for the reuse of internal streams as makeup water in cooling towers, and the implementation of the reuse presented in this paper totaled savings of 385,440 m(3)/year of water, which means a sufficient volume to supply 6350 inhabitants for a period of one year, considering the average water consumption per capita in Brazil; in addition to 201,480 m(3)/year of wastewater that would no longer be generated

  11. Optimal C-arm angulation during transcatheter aortic valve replacement: Accuracy of a rotational C-arm computed tomography based three dimensional heart model.

    Science.gov (United States)

    Veulemans, Verena; Mollus, Sabine; Saalbach, Axel; Pietsch, Max; Hellhammer, Katharina; Zeus, Tobias; Westenfeld, Ralf; Weese, Jürgen; Kelm, Malte; Balzer, Jan

    2016-10-26

    To investigate the accuracy of a rotational C-arm CT-based 3D heart model to predict an optimal C-arm configuration during transcatheter aortic valve replacement (TAVR). Rotational C-arm CT (RCT) under rapid ventricular pacing was performed in 57 consecutive patients with severe aortic stenosis as part of the pre-procedural cardiac catheterization. With prototype software each RCT data set was segmented using a 3D heart model. From that the line of perpendicularity curve was obtained that generates a perpendicular view of the aortic annulus according to the right-cusp rule. To evaluate the accuracy of a model-based overlay we compared model- and expert-derived aortic root diameters. For all 57 patients in the RCT cohort diameter measurements were obtained from two independent operators and were compared to the model-based measurements. The inter-observer variability was measured to be in the range of 0°-12.96° of angular C-arm displacement for two independent operators. The model-to-operator agreement was 0°-13.82°. The model-based and expert measurements of aortic root diameters evaluated at the aortic annulus ( r = 0.79, P optimal C-arm configuration, potentially simplifying current clinical workflows before and during TAVR.

  12. Web-Based, Pictograph-Formatted Discharge Instructions for Low-Literacy Older Adults After Hip Replacement Surgery: Findings of End-User Evaluation of the Website.

    Science.gov (United States)

    Choi, Jeungok; Jacelon, Cynthia S; Kalmakis, Karen A

    The purpose of this study was to develop web-based, pictograph-formatted discharge instructions and evaluate the website with intended users to maximize the relevance and clarity of the website. A descriptive study. Low-literacy text and 45 sets of pictographs were implemented in web-based instructions. The content, design, function, and navigation of the website were reviewed by 15 low-literate older adults following hip replacement surgery. Participants observed that the simple line drawings with clear background were well suited to web pages and helped to convey the points made. They also suggested changes such as adding an additional alphabetical index menu to enhance easy navigation and removing hypertext links to avoid distraction. Web-based, pictograph-formatted discharge instructions were well received by low-literate older adults, who perceived the website easy to use and understand. A pictograph-formatted approach may provide effective strategies to promote understanding of lengthy, complex action-based discharge instructions in rehabilitation facilities.

  13. Exploring viscosity, polarity and temperature sensitivity of BODIPY-based molecular rotors.

    Science.gov (United States)

    Vyšniauskas, Aurimas; López-Duarte, Ismael; Duchemin, Nicolas; Vu, Thanh-Truc; Wu, Yilei; Budynina, Ekaterina M; Volkova, Yulia A; Peña Cabrera, Eduardo; Ramírez-Ornelas, Diana E; Kuimova, Marina K

    2017-09-27

    Microviscosity is a key parameter controlling the rate of diffusion and reactions on the microscale. One of the most convenient tools for measuring microviscosity is by fluorescent viscosity sensors termed 'molecular rotors'. BODIPY-based molecular rotors in particular proved extremely useful in combination with fluorescence lifetime imaging microscopy, for providing quantitative viscosity maps of living cells as well as measuring dynamic changes in viscosity over time. In this work, we investigate several new BODIPY-based molecular rotors with the aim of improving on the current viscosity sensing capabilities and understanding how the structure of the fluorophore is related to its function. We demonstrate that due to subtle structural changes, BODIPY-based molecular rotors may become sensitive to temperature and polarity of their environment, as well as to viscosity, and provide a photophysical model explaining the nature of this sensitivity. Our data suggests that a thorough understanding of the photophysics of any new molecular rotor, in environments of different viscosity, temperature and polarity, is a must before moving on to applications in viscosity sensing.

  14. Model of self assembled monolayer based molecular diodes made of ferrocenyl-alkanethiols

    Science.gov (United States)

    Duche, David; Planchoke, Ujwol; Dang, Florian-Xuan; Le Rouzo, Judikael; Bescond, Marc; Simon, Jean-Jacques; Balaban, Teodor Silviu; Escoubas, Ludovic

    2017-03-01

    There has been significant work investigating the use of self assembled monolayers (SAMs) made of ferrocenyl terminated alkanethiols for realizing molecular diodes, leading to remarkably large forward-to-reverse current rectification ratios. In this study, we use a multiband barrier tunneling model to examine the electrical properties of SAM-based molecular diodes made of HSC9Fc, HSC11Fc, and HSCiFcC13-i (0 ≤ i ≤ 13). Using our simple physical model, we reproduce the experimental data of charge transport across various ferrocenyl substituted alkanethiols performed by Nijhuis, Reus, and Whitesides [J. Am. Chem. Soc. 132, 18386-184016 (2010)] and Yuan et al. [Nat. Commun. 6, 6324 (2015)]. Especially, the model allows predicting the rectification direction in HSCiFcC13-i (0 ≤ i ≤ 13) based molecular diodes depending on the position of the ferrocenyl (Fc) moiety within the molecules. We show that the asymmetry of the barrier length at both sides of the Highest Occupied Molecular Orbital of the ferrocenyl moiety strongly contributes to the rectifying properties of ferrocenyl-alkanethiol based molecular junctions. Furthermore, our results reveal that bound and quasi-bound states play an important role in the charge transport.

  15. Molecular basis sets - a general similarity-based approach for representing chemical spaces.

    Science.gov (United States)

    Raghavendra, Akshay S; Maggiora, Gerald M

    2007-01-01

    A new method, based on generalized Fourier analysis, is described that utilizes the concept of "molecular basis sets" to represent chemical space within an abstract vector space. The basis vectors in this space are abstract molecular vectors. Inner products among the basis vectors are determined using an ansatz that associates molecular similarities between pairs of molecules with their corresponding inner products. Moreover, the fact that similarities between pairs of molecules are, in essentially all cases, nonzero implies that the abstract molecular basis vectors are nonorthogonal, but since the similarity of a molecule with itself is unity, the molecular vectors are normalized to unity. A symmetric orthogonalization procedure, which optimally preserves the character of the original set of molecular basis vectors, is used to construct appropriate orthonormal basis sets. Molecules can then be represented, in general, by sets of orthonormal "molecule-like" basis vectors within a proper Euclidean vector space. However, the dimension of the space can become quite large. Thus, the work presented here assesses the effect of basis set size on a number of properties including the average squared error and average norm of molecular vectors represented in the space-the results clearly show the expected reduction in average squared error and increase in average norm as the basis set size is increased. Several distance-based statistics are also considered. These include the distribution of distances and their differences with respect to basis sets of differing size and several comparative distance measures such as Spearman rank correlation and Kruscal stress. All of the measures show that, even though the dimension can be high, the chemical spaces they represent, nonetheless, behave in a well-controlled and reasonable manner. Other abstract vector spaces analogous to that described here can also be constructed providing that the appropriate inner products can be directly

  16. Aeronautical Information System Replacement -

    Data.gov (United States)

    Department of Transportation — Aeronautical Information System Replacement is a web-enabled, automation means for the collection and distribution of Service B messages, weather information, flight...

  17. Synthesis of ordered mesoporous carbon/tungsten carbides as a replacement of platinum-based electrocatalyst for methanol oxidation

    International Nuclear Information System (INIS)

    Zheng, Huajun; Chen, Zuo; Li, Yang; Ma, Chun’an

    2013-01-01

    The mesoporous material ordered mesoporous carbon/tungsten carbide (OMC/WC) was prepared and used as electrocatalyst for methanol electro-oxidation. WC embedded OMCs was synthesized through carbothermal reactions with a blow of argon and hydrogen by employing ammonium metatungstate as a precursor. In this method, because OMC acted both as the support and the carbon sources, not only the surface area of materials is enlarged, but also the generation of deposit carbon which covers the active sites can be effectively avoided. The characterization, which carried out by X-ray diffraction, Transmission electron microscopy and N 2 adsorption–desorption measurement showed a homogeneous distribution of WC throughout the surface of the mesoporous carbon and the surface area of OMC/WCs was up to 344 m 2 /g. Electro-catalytic properties and mechanism of methanol oxidation on the OMC/WCs electrode has been investigated using cyclic voltammetry and in situ FTIR technique. The results showed that there was only one characteristic methanol oxidation peak during the whole potential scan on the OMC/WCs electrode surface, it also showed an improved CO tolerance of the WC surface. It proved that tungsten carbide had good electro-catalytic property close to that of the Pt-based materials for methanol oxidation and provided a new idea for developing electrode materials in the future

  18. Validation of risk stratification models in acute myeloid leukemia using sequencing-based molecular profiling.

    Science.gov (United States)

    Wang, M; Lindberg, J; Klevebring, D; Nilsson, C; Mer, A S; Rantalainen, M; Lehmann, S; Grönberg, H

    2017-10-01

    Risk stratification of acute myeloid leukemia (AML) patients needs improvement. Several AML risk classification models based on somatic mutations or gene-expression profiling have been proposed. However, systematic and independent validation of these models is required for future clinical implementation. We performed whole-transcriptome RNA-sequencing and panel-based deep DNA sequencing of 23 genes in 274 intensively treated AML patients (Clinseq-AML). We also utilized the The Cancer Genome Atlas (TCGA)-AML study (N=142) as a second validation cohort. We evaluated six previously proposed molecular-based models for AML risk stratification and two revised risk classification systems combining molecular- and clinical data. Risk groups stratified by five out of six models showed different overall survival in cytogenetic normal-AML patients in the Clinseq-AML cohort (P-value0.5). Risk classification systems integrating mutational or gene-expression data were found to add prognostic value to the current European Leukemia Net (ELN) risk classification. The prognostic value varied between models and across cohorts, highlighting the importance of independent validation to establish evidence of efficacy and general applicability. All but one model replicated in the Clinseq-AML cohort, indicating the potential for molecular-based AML risk models. Risk classification based on a combination of molecular and clinical data holds promise for improved AML patient stratification in the future.

  19. Options for Heart Valve Replacement

    Science.gov (United States)

    ... are the most commonly replaced valves. Pulmonary and tricuspid valve replacements are fairly uncommon in adults. Replacing a ... Problems and Causes • Risks, Signs and Symptoms • Accurate Diagnosis • Treatment Options ... Repair Valve Replacement - Ross Procedure - Newer Surgery Options - ...

  20. Optimization of station battery replacement

    International Nuclear Information System (INIS)

    Jancauskas, J.R.; Shook, D.A.

    1994-01-01

    During a loss of ac power at a nuclear generating station (including diesel generators), batteries provide the source of power which is required to operate safety-related components. Because traditional lead-acid batteries have a qualified life of 20 years, the batteries must be replaced a minimum of once during a station's lifetime, twice if license extension is pursued, and more often depending on actual in-service dates and the results of surveillance tests. Replacement of batteries often occurs prior to 20 years as a result of systems changes caused by factors such as Station Blackout Regulations, control system upgrades, incremental load growth, and changes in the operating times of existing equipment. Many of these replacement decisions are based on the predictive capabilities of manual design basis calculations. The inherent conservatism of manual calculations may result in battery replacements occurring before actually required. Computerized analysis of batteries can aid in optimizing the timing of replacements as well as in interpreting service test data. Computerized analysis also provides large benefits in maintaining the as-configured load profile and corresponding design margins, while also providing the capability of quickly analyze proposed modifications and response to internal and external audits

  1. Optimization of station battery replacement

    Science.gov (United States)

    Jancauskas, J. R.; Shook, D. A.

    1994-08-01

    During a loss of ac power at a nuclear generating station (including diesel generators), batteries provide the source of power which is required to operate safety-related components. Because traditional lead-acid batteries have a qualified life of 20 years, the batteries must be replaced a minimum of once during a station's lifetime, twice if license extension is pursued, and more often depending on actual in-service dates and the results of surveillance tests. Replacement of batteries often occurs prior to 20 years as a result of systems changes caused by factors such as Station Blackout Regulations, control system upgrades, incremental load growth, and changes in the operating times of existing equipment. Many of these replacement decisions are based on the predictive capabilities of manual design basis calculations. The inherent conservatism of manual calculations may result in battery replacements occurring before actually required. Computerized analysis of batteries can aid in optimizing the timing of replacements as well as in interpreting service test data. Computerized analysis also provides large benefits in maintaining the as-configured load profile and corresponding design margins, while also providing the capability to quickly analyze proposed modifications and respond to internal and external audits.

  2. Prediction of Sliding Friction Coefficient Based on a Novel Hybrid Molecular-Mechanical Model.

    Science.gov (United States)

    Zhang, Xiaogang; Zhang, Yali; Wang, Jianmei; Sheng, Chenxing; Li, Zhixiong

    2018-08-01

    Sliding friction is a complex phenomenon which arises from the mechanical and molecular interactions of asperities when examined in a microscale. To reveal and further understand the effects of micro scaled mechanical and molecular components of friction coefficient on overall frictional behavior, a hybrid molecular-mechanical model is developed to investigate the effects of main factors, including different loads and surface roughness values, on the sliding friction coefficient in a boundary lubrication condition. Numerical modelling was conducted using a deterministic contact model and based on the molecular-mechanical theory of friction. In the contact model, with given external loads and surface topographies, the pressure distribution, real contact area, and elastic/plastic deformation of each single asperity contact were calculated. Then asperity friction coefficient was predicted by the sum of mechanical and molecular components of friction coefficient. The mechanical component was mainly determined by the contact width and elastic/plastic deformation, and the molecular component was estimated as a function of the contact area and interfacial shear stress. Numerical results were compared with experimental results and a good agreement was obtained. The model was then used to predict friction coefficients in different operating and surface conditions. Numerical results explain why applied load has a minimum effect on the friction coefficients. They also provide insight into the effect of surface roughness on the mechanical and molecular components of friction coefficients. It is revealed that the mechanical component dominates the friction coefficient when the surface roughness is large (Rq > 0.2 μm), while the friction coefficient is mainly determined by the molecular component when the surface is relatively smooth (Rq friction coefficient are recommended.

  3. Adsorption of silane films on iron surfaces: Characterization of films and development of novel silane-based pretreatments to replace chromates and phosphates

    Science.gov (United States)

    Zhang, Chunbin

    This work mainly consists of three parts. The first part deals with characterization of silane films on metal surfaces (iron) by various analytical techniques. The second part describes the development of novel silane-based pretreatments of cold rolled steel (CRS) which may be used for the replacement of pretreatments based on phosphating with chromating as a final rinse. The third part focuses on the corrosion performance of polyurethane-power-paint-coated CRS panels by means of electrochemical impedance spectroscopy. In the first part of this work, films deposited on polished iron surfaces from solutions of gamma-aminopropyltriethoxysilane (gamma-APS), 1,2-bis(triethoxysilyl) ethane (BTSE), their mixtures, and other silanes were characterized by means of ellipsometry, Reflection-Absorption Infrared Spectroscopy, Time-of-Flight Secondary Ion Mass Spectrometry, and etc. The purpose of the second part of this work was to develop novel silane-based pretreatments that can replace the commercially used phosphating pretreatment with a chromate final rinse for CRS for the benefit of a cleaner environment. The corrosion performance of the coated CRS panels was studied by means of a cyclic corrosion test and the standard ASTM salt spray test B117. A novel silane-based pretreatment, namely, a two step silane treatment, which used two silanes, one organofunctional silane (gamma-APS) and one non-functional silane (BTSE), was developed. Results obtained from cyclic corrosion and salt spray tests showed that the two step silane treatment provided corrosion performance for CRS panels equal to the commercially used iron phosphating pretreatment with a chromate final rinse. In the third part of this work, electrochemical impedance spectroscopy (EIS) was employed to study the corrosion performance of CRS panels that were coated with polyurethane powder paint. The purpose was to study the effects of various pretreatments and pH on the performance of the paint-CRS systems during

  4. From carbon to light. A new framework for estimating greenhouse gas emissions reductions from replacing fuel-based lighting with LED systems

    Energy Technology Data Exchange (ETDEWEB)

    Mills, E. [Lawrence Berkeley National Laboratory LBNL, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Jacobson, A. [Office of Policy and International Affairs, US Department of Energy, 1000 Independence Avenue SW, Washington, DC 20585 (United States)

    2011-11-15

    There is considerable well-intended, yet wishful anticipation about reducing greenhouse gas emissions by replacing fuel-based lighting in the developing world with grid-independent light-emitting diode (LED) lighting systems. Most estimates gloss over important practical realities that stand to erode a genuinely significant potential. The Clean Development Mechanism (CDM) is the leading system for quantifying the benefits of such projects in developing countries and embodying them in a market-based platform for trading carbon credits. However, compliance with methodologies for highly decentralized, small-scale energy saving projects currently employed in the CDM is viewed by developers of as onerous, time-consuming, and costly. In recognition of the problem, the CDM has recently placed priority on improved methodologies for estimating carbon dioxide reductions from displacement of fuel-based lighting with energy-efficient alternatives. The over-arching aim is to maintain environmental integrity without stifling sustainable emission-reduction projects and programs in the field. This article informs this process by laying out a new framework that shifts the analytical focus from highly costly yet narrow and uncertain baseline estimations to simplified methods based primarily on deemed values that focus on replacement lighting system quality and performance characteristics. The result - many elements of which have been adopted in a new methodology approved by the CDM - is more structured and rigorous than methodologies used for LED projects in the past and yet simpler to implement, i.e., entailing fewer transaction costs. Applying this new framework, we find that some off-grid lighting technologies can be expected to yield little or no emissions reductions, while well-designed ones, using products independently certified to have high quality and durability, can generate significant reductions. Enfolding quality assurance within the proposed framework will help stem

  5. Well-Defined Polyethylene-Based Random, Block, and Bilayered Molecular Cobrushes

    KAUST Repository

    Zhang, Hefeng

    2015-06-09

    Novel well-defined polyethylene-based random, block, and bilayered molecular cobrushes were synthesized through the macromonomer strategy. Two steps were involved in this approach: (i) synthesis of norbornyl-terminated macromonomers of polyethylene (PE), polycaprolactone (PCL), poly(ethylene oxide) (PEO), and polystyrene (PS), as well as polyethylene-b-polycaprolactone (PE-b-PCL), by esterification of the hydroxyl-terminated precursors (PE, PCL, PEO, PS, and PE-b-PCL) with 5-norbornene-2-carboxylic acid and (ii) ring-opening metathesis (co)polymerization of the resulting macromonomers to afford the PE-based molecular cobrushes. The PE-macromonomers were synthesized by polyhomologation of dimethylsulfoxonium methylide, while the others by anionic polymerization. Proton nuclear magnetic resonance spectroscopy (1H NMR) and high-temperature gel permeation chromatography (HT-GPC) were used to imprint the molecular characteristics of all macromonomers and molecular brushes and differential scanning calorimetry (DSC) for the thermal properties. The bilayered molecular cobrushes of P(PE-b-PCL) adopt a wormlike morphology on silica wafer as visualized by atomic force microscopy (AFM). © 2015 American Chemical Society.

  6. Base de linhas moleculares para síntese espectral estelar

    Science.gov (United States)

    Milone, A.; Sanzovo, G.

    2003-08-01

    A análise das abundâncias quí micas fotosféricas em estrelas do tipo solar ou tardia, através do cálculo teórico de seus espectros, emprega a espectroscopia de alta resolução e necessita de uma base representativa de linhas atômicas e moleculares com suas respectivas constantes bem determinadas. Nesse trabalho, utilizamos como ponto de partida as extensas listas de linhas espectrais de sistemas eletrônicos de algumas moléculas diatômicas compiladas por Kurucz para a construção de uma base de linhas moleculares para a sí ntese espectral estelar. Revisamos as determinações dos fatores rotacionais de Honl-London das forças de oscilador das linhas moleculares, para cada banda vibracional de alguns sistemas eletrônicos, seguindo a regra usual de normalização. Usamos as forças de oscilador eletrônicas da literatura. Os fatores vibracionais de Franck-Condon de cada banda foram especialmente recalculados empregando-se novas constantes moleculares. Reproduzimos, com êxito, as absorções espectrais de determinadas bandas eletrônicas-vibracionais das espécies moleculares C12C12, C12N14 e Mg24H em espectros de estrelas de referência como o Sol e Arcturus.

  7. Radiation Source Replacement Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, Jeffrey W.; Moran, Traci L.; Bond, Leonard J.

    2010-12-01

    This report summarizes a Radiation Source Replacement Workshop in Houston Texas on October 27-28, 2010, which provided a forum for industry and researchers to exchange information and to discuss the issues relating to replacement of AmBe, and potentially other isotope sources used in well logging.

  8. Development of new candidate gene and EST-based molecular markers for Gossypium species

    Science.gov (United States)

    New source of molecular markers accelerates the efforts in improving cotton fiber traits and aid in developing high-density integrated genetic maps. We developed new markers based on candidate genes and G. arboreum expressed sequence tag (EST) sequences, and validated them through amplification, ge...

  9. Synthesis and molecular structure of chiral metallo-based sterically overcrowded alkenes

    NARCIS (Netherlands)

    Wiel, Matthijs K.J. ter; Meetsma, Auke; Feringa, Bernard

    2002-01-01

    A four step synthesis of pyridyl-2-yl-thioxanthen-9-ylidene-isoquinolines is described. The corresponding palladium complexes are the first examples of a novel class of chiral, metallo-based, sterically overcrowded alkenes. The crystal and molecular structure of the palladium dichloride complex

  10. Maximizing genetic differentiation in core collections by PCA-based clustering of molecular marker data

    NARCIS (Netherlands)

    Heerwaarden, van J.; Odong, T.L.; Eeuwijk, van F.A.

    2013-01-01

    Developing genetically diverse core sets is key to the effective management and use of crop genetic resources. Core selection increasingly uses molecular marker-based dissimilarity and clustering methods, under the implicit assumption that markers and genes of interest are genetically correlated. In

  11. Application of Group-Based QSAR and Molecular Docking in the ...

    African Journals Online (AJOL)

    Selection of training and test sets. Fragment-based molecular descriptor calculations resulted in a pool of 325 different two-dimensional descriptors divided into 110,. 100, and 115 descriptors for fragment R1, R2, and R3, respectively. The sphere exclusion method with a dissimilarity value of +1 resulted in a training set of ...

  12. Encapsulation and solid state sequestration of gases by calix[6]arene-based molecular containers.

    Science.gov (United States)

    Lavendomme, Roy; Ajami, Daniela; Moerkerke, Steven; Wouters, Johan; Rissanen, Kari; Luhmer, Michel; Jabin, Ivan

    2017-06-13

    Two calix[6]arene-based molecular containers were synthesized in high yields. These containers can encapsulate small guests through a unique "rotating door" complexation process. The sequestration of greenhouse gases is clearly demonstrated. They can be stored in the solid state for long periods and released via dissolution of the inclusion complex.

  13. Molecular Docking of Enzyme Inhibitors: A Computational Tool for Structure-Based Drug Design

    Science.gov (United States)

    Rudnitskaya, Aleksandra; Torok, Bela; Torok, Marianna

    2010-01-01

    Molecular docking is a frequently used method in structure-based rational drug design. It is used for evaluating the complex formation of small ligands with large biomolecules, predicting the strength of the bonding forces and finding the best geometrical arrangements. The major goal of this advanced undergraduate biochemistry laboratory exercise…

  14. Reversible, High Molecular Weight Palladium and Platinum Coordination Polymers Based on Phosphorus Ligands

    NARCIS (Netherlands)

    Paulusse, Jos Marie Johannes; Huijbers, Jeroen P.J.; Sijbesma, Rint P.

    2005-01-01

    A general strategy for the preparation and characterization of high molecular weight coordination polymers based on bifunctional phosphorus ligands and palladium or platinum dichloride is described. Metal-to-ligand stoichiometry is of key importance for the formation of linear coordination polymers

  15. Fast parallel DNA-based algorithms for molecular computation: the set-partition problem.

    Science.gov (United States)

    Chang, Weng-Long

    2007-12-01

    This paper demonstrates that basic biological operations can be used to solve the set-partition problem. In order to achieve this, we propose three DNA-based algorithms, a signed parallel adder, a signed parallel subtractor and a signed parallel comparator, that formally verify our designed molecular solutions for solving the set-partition problem.

  16. Molecular modeling of the conductivity changes of the emeraldine base polyaniline due to protonic acid doping

    NARCIS (Netherlands)

    Chen, X.; Yuan, C.A.; Wong, C.K.Y.; Zhang, G.

    2012-01-01

    We propose a molecular modeling strategy, which is capable of predicting the conductivity change of emeraldine base polyaniline polymer due to different degree of protonic acid doping. The method is comprised of two key steps: (1) generating the amorphous unit cells with given number of polymer

  17. Molecularly imprinted fluorescent probe based on FRET for selective and sensitive detection of doxorubicin

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhifeng, E-mail: 897061147@qq.com [College of Chemistry and Materials Science, Hengyang Normal University, Key Laboratory of Functional Organometallic Materials of Hunan Province University, Hengyang 421008 (China); Deng, Peihong; Li, Junhua [College of Chemistry and Materials Science, Hengyang Normal University, Key Laboratory of Functional Organometallic Materials of Hunan Province University, Hengyang 421008 (China); Xu, Li [Department of Applied Chemistry, College of Materials and Energy, South China Agricultural University, Guangzhou 510642 (China); Tang, Siping [College of Chemistry and Materials Science, Hengyang Normal University, Key Laboratory of Functional Organometallic Materials of Hunan Province University, Hengyang 421008 (China)

    2017-04-15

    Highlights: • FRET-based molecularly imprinted probe for detection of doxorubicin was prepared. • The detection limit of the probe was 13.8 nM for doxorubicin. • The FRET-based probe had a higher selectivity for the template than ordinary MIMs. - Abstract: In this work, a new type of fluorescent probe for detection of doxorubicin has been constructed by the combined use of fluorescence resonance energy transfer (FRET) technology and molecular imprinting technique (MIT). Using doxorubicin as the template, the molecularly imprinted polymer thin layer was fabricated on the surfaces of carbon dot (CD) modified silica by sol-gel polymerization. The excitation energy of the fluorescent donor (CDs) could be transferred to the fluorescent acceptor (doxorubicin). The FRET based fluorescent probe demonstrated high sensitivity and selectivity for doxorubicin. The detection limit was 13.8 nM. The fluorescent probe was successfully applied for detecting doxorubicin in doxorubicin-spiked plasmas with a recovery of 96.8–103.8%, a relative standard deviation (RSD) of 1.3–2.8%. The strategy for construction of FRET-based molecularly imprinted materials developed in this work is very promising for analytical applications.

  18. Photo- and electro-chromism of diarylethene modified ITO electrodes - towards molecular based read-write-erase information storage

    NARCIS (Netherlands)

    Areephong, J.; Browne, W.R.; Katsonis, N.; Feringa, B.L.

    2006-01-01

    Molecular memory devices based on dithienylethene switch modified ITO electrodes undergo reversible ring opening/closing both photo- and electro-chemically with non-destructive electrochemical readout.

  19. Looking toward the future: novel strategies based on molecular pathogenesis of acute lymphoblastic leukemia.

    Science.gov (United States)

    Abutalib, Syed A; Wetzler, Meir; Stock, Wendy

    2009-10-01

    There has been exponential growth in our understanding of the pathobiology of acute lymphoblastic leukemia (ALL) leading to the discovery of new prognostic markers and potential new treatment strategies. The inferior treatment outcome observed in adults with ALL in comparison with children with ALL means that new therapeutic approaches are required, preferably based on novel molecular insights. In this concluding article, the important themes that have been discussed in earlier articles are reviewed. Looking toward the future, the authors highlight several of the new therapeutic agents and discuss some of the recently described molecular genetic aberrations that might serve as therapeutic targets for future drug development.

  20. The any particle molecular orbital grid-based Hartree-Fock (APMO-GBHF) approach.

    Science.gov (United States)

    Posada, Edwin; Moncada, Félix; Reyes, Andrés

    2018-02-28

    The any particle molecular orbital grid-based Hartree-Fock approach (APMO-GBHF) is proposed as an initial step to perform multi-component post-Hartree-Fock, explicitly correlated, and density functional theory methods without basis set errors. The method has been applied to a number of electronic and multi-species molecular systems. Results of these calculations show that the APMO-GBHF total energies are comparable with those obtained at the APMO-HF complete basis set limit. In addition, results reveal a considerable improvement in the description of the nuclear cusps of electronic and non-electronic densities.

  1. First-principles study of the electronic transport properties of the anthraquinone-based molecular switch

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, P., E-mail: ss_zhaop@ujn.edu.c [School of Science, University of Jinan, Jinan 250022 (China); Liu, D.S. [School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Department of Physics, Jining University, Qufu 273155 (China); Wang, P.J.; Zhang, Z. [School of Science, University of Jinan, Jinan 250022 (China); Fang, C.F.; Ji, G.M. [School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China)

    2011-02-15

    By applying non-equilibrium Green's function (NEGF) formalism combined with first-principles density functional theory (DFT), we have investigated the electronic transport properties of the anthraquinone-based molecular switch. The molecule that comprises the switch can be converted between the hydroquinone (HQ) and anthraquinone (AQ) forms via redox reactions. The transmission spectra of these two forms are remarkably distinctive. Our results show that the current through the HQ form is significantly larger than that through the AQ form, which suggests that this system has attractive potential application in future molecular switch technology.

  2. First-principles study of the electronic transport properties of the anthraquinone-based molecular switch

    International Nuclear Information System (INIS)

    Zhao, P.; Liu, D.S.; Wang, P.J.; Zhang, Z.; Fang, C.F.; Ji, G.M.

    2011-01-01

    By applying non-equilibrium Green's function (NEGF) formalism combined with first-principles density functional theory (DFT), we have investigated the electronic transport properties of the anthraquinone-based molecular switch. The molecule that comprises the switch can be converted between the hydroquinone (HQ) and anthraquinone (AQ) forms via redox reactions. The transmission spectra of these two forms are remarkably distinctive. Our results show that the current through the HQ form is significantly larger than that through the AQ form, which suggests that this system has attractive potential application in future molecular switch technology.

  3. Radiation-chemical yields of molecular hydrogen formation in cyclohexane based alcohols

    International Nuclear Information System (INIS)

    Val'ter, A.I.; Kovalev, G.V.

    1988-01-01

    Molecular hydrogen radiation-chemical yields in γ-irradiated cyclohexanol, 1.2-cis- and 1.2-trans-cyclohexandiols and inositol are determined within the general problem frameworks of radiolysis mechanism for cyclohexanering-base alcohols. Irradiation was conducted at 77 and 293 K, dose rate - 4 Gy/s. Hydrogen concentration in all irradiated alcohols depends linearly on the dose. Radiation-chemical yields of H 2 and of stabilized radicals, as well, in the irradiated crystalline alcohols are analyzed depending on the irradiation temperature, alcohol molecular structure

  4. PyRosetta: a script-based interface for implementing molecular modeling algorithms using Rosetta

    OpenAIRE

    Chaudhury, Sidhartha; Lyskov, Sergey; Gray, Jeffrey J.

    2010-01-01

    Summary: PyRosetta is a stand-alone Python-based implementation of the Rosetta molecular modeling package that allows users to write custom structure prediction and design algorithms using the major Rosetta sampling and scoring functions. PyRosetta contains Python bindings to libraries that define Rosetta functions including those for accessing and manipulating protein structure, calculating energies and running Monte Carlo-based simulations. PyRosetta can be used in two ways: (i) interactive...

  5. Empirical D3 Dispersion as a Replacement for ab Initio Dispersion Terms in Density Functional Theory-Based Symmetry-Adapted Perturbation Theory.

    Science.gov (United States)

    Sedlak, Robert; Řezáč, Jan

    2017-04-11

    In density functional theory-based symmetry-adapted perturbation theory (DFT-SAPT) interaction energy calculations, the most demanding step is the calculation of the London dispersion term. For this bottleneck to be avoided and DFT-SAPT to be made applicable to larger systems, the ab initio dispersion terms can be replaced by one calculated empirically at an almost negligible cost ( J. Phys. Chem. A 2011 ; 115 , 11321 - 11330 ). We present an update of this approach that improves accuracy and makes the method applicable to a wider range of systems. It is based on Grimme's D3 dispersion correction for DFT, where the damping function is changed to one suitable for the calculation of the complete dispersion energy. The best results have been achieved with the Tang-Toennies damping function. It has been parametrized on the S66×8 data set for which we report density fitting DFT-SAPT/aug-cc-pVTZ interaction energy decomposition. The method has been validated on a diverse set of noncovalent systems including difficult cases such as very compact noncovalent complexes of charge-transfer type. The root-mean-square errors in the complete test set are 0.73 and 0.42 kcal mol -1 when charge-transfer complexes are excluded. The proposed empirical dispersion terms can also be used outside the DFT-SAPT framework, e.g., for the estimation of the amount of dispersion in a calculation where only the total interaction energy is known.

  6. Molecular biology-based methods for quantification of bacteria in mixed culture: perspectives and limitations.

    Science.gov (United States)

    Nagarajan, Karthiga; Loh, Kai-Chee

    2014-08-01

    Species-specific enumeration of mixed community is invaluable as it facilitates a better understanding of the significance of the individual strains, their interactions, and the underlying mechanisms of community dynamics. Mixed microbial community has been characterized by microbiological, biochemical, or molecular biology-based methods. While microbiological and biochemical techniques do not provide adequate quantitative information of the members of the consortia and require additional techniques for a more comprehensive analysis, molecular biology-based methods analyze the microbial consortium based on specific DNA sequences and do not require isolation and culturing of bacteria for quantitative analysis. These methods outshine conventional culture-based techniques in terms of better sensitivity, reproducibility, and reliability. Quantitative molecular biology methods have been classified as PCR-based and probe hybridization methods. The PCR-based methods includes quantitative real-time PCR and terminal restriction fragment length polymorphism, while fluorescent in situ hybridization and DNA microarrays fall under probe hybridization methods. The workflow, the quantification methods, and their potential applications are discussed in this review by highlighting their advantages and possible limitations.

  7. Gold-based hybrid nanomaterials for biosensing and molecular diagnostic applications.

    Science.gov (United States)

    Kim, Jung Eun; Choi, Ji Hye; Colas, Marion; Kim, Dong Ha; Lee, Hyukjin

    2016-06-15

    The properties of gold nanomaterials are particularly of interest to many researchers, since they show unique physiochemical properties such as optical adsorption of specific wavelength of light, high electrical conductance with rich surface electrons, and facile surface modification with sulfhydryl groups. These properties have facilitated the use of gold nanomaterials in the development of various hybrid systems for biosensors and molecular diagnostics. Combined with various synthetic materials such as fluorescence dyes, polymers, oligonucleotides, graphene oxides (GO), and quantum dots (QDs), the gold-based hybrid nanomaterials offer multi-functionalities in molecular detection with high specificity and sensitivity. These two aspects result in the increase of detection speed as well as the lower detection limits, having shown that this diagnosis method is more effective than other conventional ones. In this review, we have highlighted various examples of nanomaterials for biosensing and molecular diagnostics. The gold-based hybrid systems are categorized by three distinct detection approaches, in which include (1) optical, such as surface plasmon resonance (SPR), RAMAN, and surface-enhanced Raman scattering (SERS), (2) fluorescence, such as förster resonance energy transfer (FRET) and nanomaterial surface energy transfer (NSET), and (3) electrochemical, such as potentiometic, amperometric, and conductometric. Each example provides the detailed mechanism of molecular detection as well as the supporting experimental result with the limit of detection (LOD). Lastly, future perspective on novel development of gold-based hybrid nanomaterials is discussed as well as their challenges. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Integration of culture-based and molecular analysis of a complex sponge-associated bacterial community.

    Directory of Open Access Journals (Sweden)

    Naomi F Montalvo

    Full Text Available The bacterial communities of sponges have been studied using molecular techniques as well as culture-based techniques, but the communities described by these two methods are remarkably distinct. Culture-based methods describe communities dominated by Proteobacteria, and Actinomycetes while molecular methods describe communities dominated by predominantly uncultivated groups such as the Chloroflexi, Acidobacteria, and Acidimicrobidae. In this study, we used a wide range of culture media to increase the diversity of cultivable bacteria from the closely related giant barrel sponges, Xestospongia muta collected from the Florida Keys, Atlantic Ocean and Xestospongia testudinaria, collected from Indonesia, Pacific Ocean. Over 400 pure cultures were isolated and identified from X. muta and X. testudinaria and over 90 bacterial species were represented. Over 16,000 pyrosequences were analyzed and assigned to 976 OTUs. We employed both cultured-based methods and pyrosequencing to look for patterns of overlap between the culturable and molecular communities. Only one OTU was found in both the molecular and culturable communities, revealing limitations inherent in both approaches.

  9. Integration of culture-based and molecular analysis of a complex sponge-associated bacterial community.

    Science.gov (United States)

    Montalvo, Naomi F; Davis, Jeanette; Vicente, Jan; Pittiglio, Raquel; Ravel, Jacques; Hill, Russell T

    2014-01-01

    The bacterial communities of sponges have been studied using molecular techniques as well as culture-based techniques, but the communities described by these two methods are remarkably distinct. Culture-based methods describe communities dominated by Proteobacteria, and Actinomycetes while molecular methods describe communities dominated by predominantly uncultivated groups such as the Chloroflexi, Acidobacteria, and Acidimicrobidae. In this study, we used a wide range of culture media to increase the diversity of cultivable bacteria from the closely related giant barrel sponges, Xestospongia muta collected from the Florida Keys, Atlantic Ocean and Xestospongia testudinaria, collected from Indonesia, Pacific Ocean. Over 400 pure cultures were isolated and identified from X. muta and X. testudinaria and over 90 bacterial species were represented. Over 16,000 pyrosequences were analyzed and assigned to 976 OTUs. We employed both cultured-based methods and pyrosequencing to look for patterns of overlap between the culturable and molecular communities. Only one OTU was found in both the molecular and culturable communities, revealing limitations inherent in both approaches.

  10. Severe childhood asthma and allergy to furry animals: refined assessment using molecular-based allergy diagnostics.

    Science.gov (United States)

    Konradsen, Jon R; Nordlund, Björn; Onell, Annica; Borres, Magnus P; Grönlund, Hans; Hedlin, Gunilla

    2014-03-01

    Allergy to cats and dogs and polysensitization towards these animals are associated with severe childhood asthma. Molecular-based allergy diagnostics offers new opportunities for improved characterization and has been suggested to be particularly useful in patients with polysensitization and/or severe asthma. The aim was to use extract- and molecular-based allergy diagnostics to compare patterns of IgE sensitization towards aeroallergens in children with problematic severe and controlled asthma. Children with a positive ImmunoCAP towards any furry animal (cat, dog or horse) were recruited from a Nationwide Swedish study on severe childhood asthma. Severe (n = 37, age 13 years) and controlled (n = 28, age 14 years) asthmatics underwent assessment of allergic sensitization by ImmunoCap (kUA /l) and immunosolid-phase allergen chip (ISAC). In addition, Asthma Control Test, spirometry and a methacholine challenge were performed. Children with severe asthma had lower asthma control (p Molecular-based allergy diagnostics revealed a more complex molecular spreading of allergen components in children with the most severe disease. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Correlation of microarray-based breast cancer molecular subtypes and clinical outcomes: implications for treatment optimization

    International Nuclear Information System (INIS)

    Kao, Kuo-Jang; Chang, Kai-Ming; Hsu, Hui-Chi; Huang, Andrew T

    2011-01-01

    Optimizing treatment through microarray-based molecular subtyping is a promising method to address the problem of heterogeneity in breast cancer; however, current application is restricted to prediction of distant recurrence risk. This study investigated whether breast cancer molecular subtyping according to its global intrinsic biology could be used for treatment customization. Gene expression profiling was conducted on fresh frozen breast cancer tissue collected from 327 patients in conjunction with thoroughly documented clinical data. A method of molecular subtyping based on 783 probe-sets was established and validated. Statistical analysis was performed to correlate molecular subtypes with survival outcome and adjuvant chemotherapy regimens. Heterogeneity of molecular subtypes within groups sharing the same distant recurrence risk predicted by genes of the Oncotype and MammaPrint predictors was studied. We identified six molecular subtypes of breast cancer demonstrating distinctive molecular and clinical characteristics. These six subtypes showed similarities and significant differences from the Perou-Sørlie intrinsic types. Subtype I breast cancer was in concordance with chemosensitive basal-like intrinsic type. Adjuvant chemotherapy of lower intensity with CMF yielded survival outcome similar to those of CAF in this subtype. Subtype IV breast cancer was positive for ER with a full-range expression of HER2, responding poorly to CMF; however, this subtype showed excellent survival when treated with CAF. Reduced expression of a gene associated with methotrexate sensitivity in subtype IV was the likely reason for poor response to methotrexate. All subtype V breast cancer was positive for ER and had excellent long-term survival with hormonal therapy alone following surgery and/or radiation therapy. Adjuvant chemotherapy did not provide any survival benefit in early stages of subtype V patients. Subtype V was consistent with a unique subset of luminal A intrinsic

  12. ChemDes: an integrated web-based platform for molecular descriptor and fingerprint computation.

    Science.gov (United States)

    Dong, Jie; Cao, Dong-Sheng; Miao, Hong-Yu; Liu, Shao; Deng, Bai-Chuan; Yun, Yong-Huan; Wang, Ning-Ning; Lu, Ai-Ping; Zeng, Wen-Bin; Chen, Alex F

    2015-01-01

    Molecular descriptors and fingerprints have been routinely used in QSAR/SAR analysis, virtual drug screening, compound search/ranking, drug ADME/T prediction and other drug discovery processes. Since the calculation of such quantitative representations of molecules may require substantial computational skills and efforts, several tools have been previously developed to make an attempt to ease the process. However, there are still several hurdles for users to overcome to fully harness the power of these tools. First, most of the tools are distributed as standalone software or packages that require necessary configuration or programming efforts of users. Second, many of the tools can only calculate a subset of molecular descriptors, and the results from multiple tools need to be manually merged to generate a comprehensive set of descriptors. Third, some packages only provide application programming interfaces and are implemented in different computer languages, which pose additional challenges to the integration of these tools. A freely available web-based platform, named ChemDes, is developed in this study. It integrates multiple state-of-the-art packages (i.e., Pybel, CDK, RDKit, BlueDesc, Chemopy, PaDEL and jCompoundMapper) for computing molecular descriptors and fingerprints. ChemDes not only provides friendly web interfaces to relieve users from burdensome programming work, but also offers three useful and convenient auxiliary tools for format converting, MOPAC optimization and fingerprint similarity calculation. Currently, ChemDes has the capability of computing 3679 molecular descriptors and 59 types of molecular fingerprints. ChemDes provides users an integrated and friendly tool to calculate various molecular descriptors and fingerprints. It is freely available at http://www.scbdd.com/chemdes. The source code of the project is also available as a supplementary file. Graphical abstract:An overview of ChemDes. A platform for computing various molecular

  13. Possibility of gas sensor based on C{sub 20} molecular devices

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Wenkai [School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025 (China); Yang, Chuanlu, E-mail: yangchuanlu@126.com [School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025 (China); Zou, Dongqing [School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Sun, Zhaopeng [School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025 (China); Ji, Guomin [Electrical and Computer Engineering, The University of Oklahoma, Norman, Tulsa, OK 74078 (United States)

    2017-06-09

    We theoretically investigate the possibility of diatomic gas detection (NO, CO, O{sub 2}) by making use of the transport properties of the C{sub 20} molecular junctions. The calculations are performed by using nonequilibrium Green's function (NEGF) formalism in combination with density functional theory (DFT). In this work, we systematically study the most stable adsorption structural configurations, adsorption energy, and the transport properties on C{sub 20} molecular junctions with these diatomic gas molecules. It is found that NO and O{sub 2} gas molecule can be detected selectively. We suggest its possibility of nanosensors for highly sensitive and selective based on C{sub 20} molecular junction systems. - Highlights: • The most favorable adsorption site is investigated. • The mechanism of gas sensors is revealed. • NO and O{sub 2} gas molecules can be detected by C{sub 20} selectively.

  14. MOLECULAR CLIPS BASED ON THE CROWN ETHERS: PROSPECTIVE RECEPTORS FOR THE Sr2+CATIONS REMOVAL

    Directory of Open Access Journals (Sweden)

    A. Yu. Lyapunov

    2015-04-01

    Full Text Available Strontium cation complexation with diphenylglycoluril-based molecular clips containing 12-crown-4, 15-crown-5, 18-crown-6 and 21-crown-7 residues was qualitatively studied by FAB mass-spectrometry. It was found that at low concentrations of Sr2+ cations molecular clip with fragments of 15-crown-5 is the most effective, and it is assumed that it is due to the formation of the most stable «sandwich-type» complex. The higher removal degree with an excess of Sr2+ cations is observed in the case of molecular clips with fragments of 18-crown-6 due to the formation of 1:2 composition complexes.

  15. Mass Spectrometry Based Molecular 3D-Cartography of Plant Metabolites.

    Science.gov (United States)

    Floros, Dimitrios J; Petras, Daniel; Kapono, Clifford A; Melnik, Alexey V; Ling, Tie-Jun; Knight, Rob; Dorrestein, Pieter C

    2017-01-01

    Plants play an essential part in global carbon fixing through photosynthesis and are the primary food and energy source for humans. Understanding them thoroughly is therefore of highest interest for humanity. Advances in DNA and RNA sequencing and in protein and metabolite analysis allow the systematic description of plant composition at the molecular level. With imaging mass spectrometry, we can now add a spatial level, typically in the micrometer-to-centimeter range, to their compositions, essential for a detailed molecular understanding. Here we present an LC-MS based approach for 3D plant imaging, which is scalable and allows the analysis of entire plants. We applied this approach in a case study to pepper and tomato plants. Together with MS/MS spectra library matching and spectral networking, this non-targeted workflow provides the highest sensitivity and selectivity for the molecular annotations and imaging of plants, laying the foundation for studies of plant metabolism and plant-environment interactions.

  16. MOLECULAR COMPLEXES OF SULPHUR DIOXIDE WITH N,O-CONTAINING ORGANIC BASES (REVIEW

    Directory of Open Access Journals (Sweden)

    R. E. Khoma

    2016-10-01

    Full Text Available The literature data on the synthesis, stoichiometry, structure and relative stability of molecular  complexes of sulphur dioxide with N,O-containing organic bases have been systematized and  generalized. It was shown that the yield of the reaction product of sulfur dioxide with organic  bases (such as amines are strongly influenced by the conditions of synthesis: the nature of  the solvent (basicity, polarity, the temperature and SO2:L ratio in the reaction medium. The stoichiometry of SO2*nL molecular complexes depends on ligand denticity, as well as its  ability to H-bonding. The reaction of the sulfur oxide (IV with organic bases can give S←N and S←O complexes. With the increase of the value of base proton affinity the decrease ΔrSN values has been marked. Characteristic parameter Δr SN = r SN – a1(rS+ rN (where rSNis the S←N donor-acceptor bond length has been determined by microwave spectroscopy and X-ray analysis, rSand rNwere the tabulated values of the homopolar covalent radii of sulphur and nitrogen heteroatoms. The dependence of formation enthalpy of molecular complexes of basic amines and spectral characteristics has been noted; enthalpy-entropy compensation for S←N and S←O complex-es has been stated. Despite the limited experimental data on the thermodynamics of complex formation and the lengths of donor-acceptor bonds for the same compounds it has been found bond S←N strength in SO2 molecular complexes to depend on the intrinsic value of ΔrSN. The contribution of van der Waals forces and charge transfer forces to the formation of molecular complexes of sulphur dioxide has been stated.

  17. Interference between concurrent resistance and endurance exercise: molecular bases and the role of individual training variables.

    Science.gov (United States)

    Fyfe, Jackson J; Bishop, David J; Stepto, Nigel K

    2014-06-01

    Concurrent training is defined as simultaneously incorporating both resistance and endurance exercise within a periodized training regime. Despite the potential additive benefits of combining these divergent exercise modes with regards to disease prevention and athletic performance, current evidence suggests that this approach may attenuate gains in muscle mass, strength, and power compared with undertaking resistance training alone. This has been variously described as the interference effect or concurrent training effect. In recent years, understanding of the molecular mechanisms mediating training adaptation in skeletal muscle has emerged and provided potential mechanistic insight into the concurrent training effect. Although it appears that various molecular signaling responses induced in skeletal muscle by endurance exercise can inhibit pathways regulating protein synthesis and stimulate protein breakdown, human studies to date have not observed such molecular 'interference' following acute concurrent exercise that might explain compromised muscle hypertrophy following concurrent training. However, given the multitude of potential concurrent training variables and the limitations of existing evidence, the potential roles of individual training variables in acute and chronic interference are not fully elucidated. The present review explores current evidence for the molecular basis of the specificity of training adaptation and the concurrent interference phenomenon. Additionally, insights provided by molecular and performance-based concurrent training studies regarding the role of individual training variables (i.e., within-session exercise order, between-mode recovery, endurance training volume, intensity, and modality) in the concurrent interference effect are discussed, along with the limitations of our current understanding of this complex paradigm.

  18. 3D-Lab: a collaborative web-based platform for molecular modeling.

    Science.gov (United States)

    Grebner, Christoph; Norrby, Magnus; Enström, Jonatan; Nilsson, Ingemar; Hogner, Anders; Henriksson, Jonas; Westin, Johan; Faramarzi, Farzad; Werner, Philip; Boström, Jonas

    2016-09-01

    The use of 3D information has shown impact in numerous applications in drug design. However, it is often under-utilized and traditionally limited to specialists. We want to change that, and present an approach making 3D information and molecular modeling accessible and easy-to-use 'for the people'. A user-friendly and collaborative web-based platform (3D-Lab) for 3D modeling, including a blazingly fast virtual screening capability, was developed. 3D-Lab provides an interface to automatic molecular modeling, like conformer generation, ligand alignments, molecular dockings and simple quantum chemistry protocols. 3D-Lab is designed to be modular, and to facilitate sharing of 3D-information to promote interactions between drug designers. Recent enhancements to our open-source virtual reality tool Molecular Rift are described. The integrated drug-design platform allows drug designers to instantaneously access 3D information and readily apply advanced and automated 3D molecular modeling tasks, with the aim to improve decision-making in drug design projects.

  19. Molecular and cellular bases of adaptation to a changing environment in microorganisms.

    Science.gov (United States)

    Bleuven, Clara; Landry, Christian R

    2016-10-26

    Environmental heterogeneity constitutes an evolutionary challenge for organisms. While evolutionary dynamics under variable conditions has been explored for decades, we still know relatively little about the cellular and molecular mechanisms involved. It is of paramount importance to examine these molecular bases because they may play an important role in shaping the course of evolution. In this review, we examine the diversity of adaptive mechanisms in the face of environmental changes. We exploit the recent literature on microbial systems because those have benefited the most from the recent emergence of genetic engineering and experimental evolution followed by genome sequencing. We identify four emerging trends: (i) an adaptive molecular change in a pathway often results in fitness trade-off in alternative environments but the effects are dependent on a mutation's genetic background; (ii) adaptive changes often modify transcriptional and signalling pathways; (iii) several adaptive changes may occur within the same molecular pathway but be associated with pleiotropy of different signs across environments; (iv) because of their large associated costs, macromolecular changes such as gene amplification and aneuploidy may be a rapid mechanism of adaptation in the short-term only. The course of adaptation in a variable environment, therefore, depends on the complexity of the environment but also on the molecular relationships among the genes involved and between the genes and the phenotypes under selection. © 2016 The Author(s).

  20. Could wind replace nuclear?

    International Nuclear Information System (INIS)

    2017-01-01

    This article aims at assessing the situation produced by a total replacement of nuclear energy by wind energy, while facing consumption demand at any moment, notably in December. The authors indicate the evolution of the French energy mix during December 2016, and the evolution of the rate between wind energy production and the sum of nuclear and wind energy production during the same month, and then give briefly some elements regarding necessary investments in wind energy to wholly replace nuclear energy. According to them, such a replacement would be ruinous

  1. Molecular design toward highly efficient photovoltaic polymers based on two-dimensional conjugated benzodithiophene.

    Science.gov (United States)

    Ye, Long; Zhang, Shaoqing; Huo, Lijun; Zhang, Maojie; Hou, Jianhui

    2014-05-20

    As researchers continue to develop new organic materials for solar cells, benzo[1,2-b:4,5-b']dithiophene (BDT)-based polymers have come to the fore. To improve the photovoltaic properties of BDT-based polymers, researchers have developed and applied various strategies leading to the successful molecular design of highly efficient photovoltaic polymers. Novel polymer materials composed of two-dimensional conjugated BDT (2D-conjugated BDT) have boosted the power conversion efficiency of polymer solar cells (PSCs) to levels that exceed 9%. In this Account, we summarize recent progress related to the design and synthesis of 2D-conjugated BDT-based polymers and discuss their applications in highly efficient photovoltaic devices. We introduce the basic considerations for the construction of 2D-conjugated BDT-based polymers and systematic molecular design guidelines. For example, simply modifying an alkoxyl-substituted BDT to form an alkylthienyl-substituted BDT can improve the polymer hole mobilities substantially with little effect on their molecular energy level. Secondly, the addition of a variety of chemical moieties to the polymer can produce a 2D-conjugated BDT unit with more functions. For example, the introduction of a conjugated side chain with electron deficient groups (such as para-alkyl-phenyl, meta-alkoxyl-phenyl, and 2-alkyl-3-fluoro-thienyl) allowed us to modulate the molecular energy levels of 2D-conjugated BDT-based polymers. Through the rational design of BDT analogues such as dithienobenzodithiophene (DTBDT) or the insertion of larger π bridges, we can tune the backbone conformations of these polymers and modulate their photovoltaic properties. We also discuss the influence of 2D-conjugated BDT on polymer morphology and the blends of these polymers with phenyl-C61 (or C71)-butyric acid methyl ester (PCBM). Finally, we summarize the various applications of the 2D-conjugated BDT-based polymers in highly efficient PSC devices. Overall, this Account

  2. A novel energy conversion based method for velocity correction in molecular dynamics simulations

    International Nuclear Information System (INIS)

    Jin, Hanhui; Liu, Ningning; Ku, Xiaoke; Fan, Jianren

    2017-01-01

    Molecular dynamics (MD) simulation has become an important tool for studying micro- or nano-scale dynamics and the statistical properties of fluids and solids. In MD simulations, there are mainly two approaches: equilibrium and non-equilibrium molecular dynamics (EMD and NEMD). In this paper, a new energy conversion based correction (ECBC) method for MD is developed. Unlike the traditional systematic correction based on macroscopic parameters, the ECBC method is developed strictly based on the physical interaction processes between the pair of molecules or atoms. The developed ECBC method can apply to EMD and NEMD directly. While using MD with this method, the difference between the EMD and NEMD is eliminated, and no macroscopic parameters such as external imposed potentials or coefficients are needed. With this method, many limits of using MD are lifted. The application scope of MD is greatly extended.

  3. Hybrid DNA and Enzyme Based Computing for Address Encoding, Link Switching and Error Correction in Molecular Communication

    Science.gov (United States)

    Walsh, Frank; Balasubramaniam, Sasitharan; Botvich, Dmitri; Suda, Tatsuya; Nakano, Tadashi; Bush, Stephen F.; Foghlú, Mícheál Ó.

    This paper proposes a biological cell-based communication protocol to enable communication between biological nanodevices. Inspired by existing communication network protocols, our solution combines two molecular computing techniques (DNA and enzyme computing), to design a protocol stack for molecular communication networks. Based on computational requirements of each layer of the stack, our solution specifies biomolecule address encoding/decoding, error correction and link switching mechanisms for molecular communication networks.

  4. Grid-based Continual Analysis of Molecular Interior for Drug Discovery, QSAR and QSPR.

    Science.gov (United States)

    Potemkin, Andrey V; Grishina, Maria A; Potemkin, Vladimir A

    2017-01-01

    In 1979, R.D.Cramer and M.Milne made a first realization of 3D comparison of molecules by aligning them in space and by mapping their molecular fields to a 3D grid. Further, this approach was developed as the DYLOMMS (Dynamic Lattice- Oriented Molecular Modelling System) approach. In 1984, H.Wold and S.Wold proposed the use of partial least squares (PLS) analysis, instead of principal component analysis, to correlate the field values with biological activities. Then, in 1988, the method which was called CoMFA (Comparative Molecular Field Analysis) was introduced and the appropriate software became commercially available. Since 1988, a lot of 3D QSAR methods, algorithms and their modifications are introduced for solving of virtual drug discovery problems (e.g., CoMSIA, CoMMA, HINT, HASL, GOLPE, GRID, PARM, Raptor, BiS, CiS, ConGO,). All the methods can be divided into two groups (classes):1. Methods studying the exterior of molecules; 2) Methods studying the interior of molecules. A series of grid-based computational technologies for Continual Molecular Interior analysis (CoMIn) are invented in the current paper. The grid-based analysis is fulfilled by means of a lattice construction analogously to many other grid-based methods. The further continual elucidation of molecular structure is performed in various ways. (i) In terms of intermolecular interactions potentials. This can be represented as a superposition of Coulomb, Van der Waals interactions and hydrogen bonds. All the potentials are well known continual functions and their values can be determined in all lattice points for a molecule. (ii) In the terms of quantum functions such as electron density distribution, Laplacian and Hamiltonian of electron density distribution, potential energy distribution, the highest occupied and the lowest unoccupied molecular orbitals distribution and their superposition. To reduce time of calculations using quantum methods based on the first principles, an original quantum

  5. Genetic variability of hull-less barley accessions based on molecular and quantitative data

    Directory of Open Access Journals (Sweden)

    Ricardo Meneses Sayd

    2015-02-01

    Full Text Available The objective of this work was to characterize and quantify the genetic, molecular, and agronomic variability of hull-less barley genotypes, for the selection of parents and identification of genotypes adapted to the irrigated production system in the Brazilian Cerrado. Eighteen hull-less barley accessions were evaluated, and three covered barley accessions served as reference. The characterization was based on 157 RAPD molecular markers and ten agronomic traits. Genetic distance matrices were obtained based on molecular markers and quantitative traits. Graphic grouping and dispersion analyses were performed. Genetic, molecular, and agronomic variability was high among genotypes. Ethiopian accessions were genetically more similar, and the Brazilian ones were genetically more distant. For agronomic traits, two more consistent groupings were obtained, one with the most two-rowed materials, and the other with six-rowed materials. The more diverging materials were the two-rowed CI 13453, CN Cerrado 5, CN Cerrado 1, and CN Cerrado 2. The PI 356466, CN Cerrado 1, PI 370799, and CI 13453 genotypes show agronomic traits of interest and, as genetically different genotypes, they are indicated for crossing, in breeding programs.

  6. Fighting high molecular weight in bioactive molecules with sub-pharmacophore-based virtual screening.

    Science.gov (United States)

    von Korff, Modest; Freyss, Joel; Sander, Thomas; Boss, Christoph; Ciana, Claire-Lise

    2012-02-27

    A new subpharmacophore-based virtual screening method is introduced. Subpharmacophores are derived from large active molecules to detect small bioactive molecules as seeds for starting points in medicinal chemistry programs. A large data set was assembled from the ChEMBL database to check the validity of this approach. Molecules for 133 targets with molecular weights between 450 and 850 were selected as queries. For the query molecules, the pharmacophore descriptors were calculated. Up to 56 000 subpharmacophore descriptors with five to seven pharmacophore points were derived from the query pharmacophores. The subpharmacophore descriptors were used as queries to screen 1079 test data sets, containing decoys and spike molecules. A maximum upper molecular weight limit of 400 Da was set for the test molecules. Three different chemical fingerprint descriptors were used for comparison purposes. The subpharmacophore approach detected active molecules for 85 out of 133 targets and outperformed the chemical fingerprints. This ligand-based virtual screening experiment was triggered by the needs of medicinal chemistry. Applying the subpharmacophore method in a medicinal chemistry program, where a lead molecule with a molecular weight of 800 Da was available, resulted in a new series of molecules with molecular weights below 400.

  7. Partial knee replacement

    Science.gov (United States)

    ... candidate for partial knee replacement and what the success rate is for your condition. Alternative Names Unicompartmental ... ADAM Health Solutions. About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow ...

  8. Tool Inventory and Replacement

    Science.gov (United States)

    Bear, W. Forrest

    1976-01-01

    Vocational agriculture teachers are encouraged to evaluate curriculum offerings, the new trends in business and industry, and develop a master tool purchase and replacement plan over a 3- to 5-year period. (HD)

  9. Slab replacement maturity guidelines.

    Science.gov (United States)

    2014-04-01

    This study investigated the use of maturity method to determine early age strength of concrete in slab : replacement application. Specific objectives were (1) to evaluate effects of various factors on the compressive : maturity-strength relationship ...

  10. Women's knowledge, attitude and practice towards menopause and hormone replacement therapy: a facility based study in Al-Ain, United Arab Emirates.

    Science.gov (United States)

    Hamid, Saima; Al-Ghufli, Fatma Rashid; Raeesi, Hanan Ali; Al-Dliufairi, Khawla Mohammed; Al-Dhaheri, Noura Salem; Al-Maskari, Fatma; Blair, Iain; Shah, Syed Mahboob

    2014-01-01

    Hormone replacement therapy (HRT) is an effective treatment for menopausal symptoms like vasomotor symptoms, sleep disturbances, mood alteration, depression, urinary tract infection, vaginal atrophy and increased health risks for osteoporosis, cardiovascular diseases and loss of cognitive function. This study was conducted to determine knowledge, attitude and practice toward menopause among women in UAE. A clinic-based cross-sectional study was carried out among women of age 40 and above. Study subjects were recruited from four Primary Health Care centres in Al Ain city. The participants were administered a questionnaire in Arabic and English, which included 33 items; socio-demographic variables, and questions related to knowledge, attitude and practices regarding menopause and HRT. Out of 177 study subjected selected, 150 (85%) completed the survey. Almost half of the participants (51%) had already experienced menopause. A substantial number of women had poor know knowledge about menopause (67%) and HRT (73%). Sixty percent of women had positive attitude towards menopause. Of the fifty three percent of women with symptoms, 35% of them did not use anything to relieve their symptoms. Knowledge about menopause varied significantly (pmenopause and HRT was found to be statistically significant. Women with reported symptoms that were bothersome had positive attitude towards HRT uptake. The study indicated that there is poor knowledge about menopause and HRT among the participants. Level of knowledge was associated with the level of education. There was a positive attitude towards menopause, with women suffering the most from menopausal symptoms showing positive attitude towards HRT.

  11. An upp-based markerless gene replacement method for genome reduction and metabolic pathway engineering in Pseudomonas mendocina NK-01 and Pseudomonas putida KT2440.

    Science.gov (United States)

    Wang, Yuanyuan; Zhang, Chi; Gong, Ting; Zuo, Zhenqiang; Zhao, Fengjie; Fan, Xu; Yang, Chao; Song, Cunjiang

    2015-06-01

    A markerless gene replacement method was adapted by combining a suicide plasmid, pEX18Tc, with a counterselectable marker, the upp gene encoding uracil phosphoribosyltransferase (UPRTase), for the medium-chain length polyhydroxyalkanoates (PHA(MCL))-producing strain Pseudomonas mendocina NK-01. An NK-01 5-fluorouracil (5-FU) resistant background strain was first constructed by deleting the chromosomal upp gene. The suicide plasmid pEX18Tc, carrying a functional allele of the upp gene of P. mendocina NK-01, was used to construct the vectors to delete the algA (encoding mannose-1-phosphate guanylyltransferase) and phaZ (encoding PHA(MCL) depolymerase) genes, and a 30 kb chromosomal fragment in the 5-FU resistant background host. The genes were removed efficiently from the genome of P. mendocina NK-01 and left a markerless chromosomal mutant. In addition, two exogenous genes were inserted into the phaC1 (PHA(MCL) polymerase) loci of Pseudomonas putida KT-∆UPP simultaneously. Thus, we constructed a genetically stable and marker-free P. putida KT2440 mutant with integrated mpd (encoding methyl parathion hydrolase (MPH)) and pytH (encoding a pyrethroid-hydrolyzing carboxylesterase (PytH)) gene on the chromosome. The upp-based counterselection system could be further adapted for P. mendocina NK-01 and P. putida KT2440 and used for genome reduction and metabolic pathway engineering. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. The replacement research reactor

    International Nuclear Information System (INIS)

    Cameron, R.

    1999-01-01

    As a consequences of the government decision in September 1997. ANSTO established a replacement research reactor project to manage the procurement of the replacement reactor through the necessary approval, tendering and contract management stages This paper provides an update of the status of the project including the completion of the Environmental Impact Statement. Prequalification and Public Works Committee processes. The aims of the project, management organisation, reactor type and expected capabilities are also described

  13. Estimating the contribution of surfactant replacement therapy to the alveolar pool: an in vivo study based on 13 C natural abundance in rabbits.

    Science.gov (United States)

    Giambelluca, Sonia; Ricci, Francesca; Simonato, Manuela; Correani, Alessio; Casiraghi, Costanza; Storti, Matteo; Cogo, Paola; Salomone, Fabrizio; Carnielli, Virgilio Paolo

    2018-04-06

    Variation of the isotopic abundance of selected nutrients and molecules have been used for pharmacological and kinetics studies under the premise that the administered molecule has a different isotopic enrichment from the isotopic background of the recipient subject. The aim of this study is to test the feasibility of assessing the contribution of exogenous surfactant phospholipids to the endogenous alveolar pool in vivo after exogenous surfactant replacement therapy in rabbits. The study consisted in measuring the consistency of 13 C/ 12 C ratio of disaturated-phosphatidylcholine palmitate (DSPC-PA) in 7 lots of poractant alfa, produced over a year, and among bronchoalveolar lavages of 20 rabbits fed with a standard chow. A pilot study was performed in a rabbit model of lavage-induced surfactant deficiency: 7 control rabbits and 4 treated with exogenous surfactant. The contribution of exogenous surfactant to the alveolar pool was assessed after intra-tracheal administration of 200 mg/kg of poractant alfa. The 13 C content of DSPC-PA was measured by Isotope Ratio Mass Spectrometry. The mean DSPC-PA 13 C/ 12 C ratio of the 7 lots of poractant alfa was -18.8 ‰ with a SD of 0.1 ‰ [Range: -18.9 ‰; -18.6 ‰]. The mean 13 C/ 12 C ratio of surfactant DSPC recovered from the lung lavage of 20 rabbits was -28.8±1.2 ‰ [Range: -31.7 ‰; -25.7 ‰]. The contribution of exogenous surfactant to the total alveolar surfactant could be calculated in the treated rabbits and it ranged from 83.9 to 89.6 %. This pilot study describes a novel method to measure the contribution of the exogenous surfactant to the alveolar pool. This method is based on the natural variation of 13 C and therefore it does not require the use of chemically synthetized tracers. This method could be useful in human research and especially in surfactant replacement studies in preterm infants. This article is protected by copyright. All rights reserved.

  14. Multicomponent Molecular Puzzles for Photofunction Design: Emission Color Variation in Lewis Acid-Base Pair Crystals Coupled with Guest-to-Host Charge Transfer Excitation.

    Science.gov (United States)

    Ono, Toshikazu; Sugimoto, Manabu; Hisaeda, Yoshio

    2015-08-05

    Simple yet ubiquitous multimolecular assembly systems with color-tunable emissions are realized by cooperative electron donor-acceptor interactions, such as the boron-nitrogen (B-N) dative bond as a Lewis acid-base pair and charge transfer (CT) interactions. These are ternary-component systems consisting of a naphthalenediimide derivative (NDI), tris(pentafluorophenyl)borane (TPFB), and aromatic molecules (guest) with an NDI:TPFB:guest ratio of 1:2:2. The crystal shows guest-dependent color-tunable emissions such as deep blue to orange when a guest molecule of benzene is replaced with other π-conjugated systems. A good correlation between the emission wavelength and ionization potential of the guest and electronic structure calculations indicated that the emission is due to the CT transition from the guest to the NDI. The present study suggests that a rational solution of multcomponent molecular puzzles would be useful for obtaining novel photofunctional solid-state systems.

  15. Contemporary nucleic acid-based molecular techniques for detection, identification, and characterization of Bifidobacterium.

    Science.gov (United States)

    Mianzhi, Yao; Shah, Nagendra P

    2017-03-24

    Bifidobacteria are one of the most important bacterial groups found in the gastrointestinal tract of humans. Medical and food industry researchers have focused on bifidobacteria because of their health-promoting properties. Researchers have historically relied on classic phenotypic approaches (culture and biochemical tests) for detection and identification of bifidobacteria. Those approaches still have values for the identification and detection of some bifidobacterial species, but they are often labor-intensive and time-consuming and can be problematic in differentiating closely related species. Rapid, accurate, and reliable methods for detection, identification, and characterization of bifidobacteria in a mixed bacterial population have become a major challenge. The advent of nucleic acid-based molecular techniques has significantly advanced isolation and detection of bifidobacteria. Diverse nucleic acid-based molecular techniques have been employed, including hybridization, target amplification, and fingerprinting. Certain techniques enable the detection, characterization, and identification at genus-, species-, and strains-levels, whereas others allow typing of species or strains of bifidobacteria. In this review, an overview of methodological principle, technique complexity, and application of various nucleic acid-based molecular techniques for detection, identification, and characterization of bifidobacteria is presented. Advantages and limitations of each technique are discussed, and significant findings based on particular techniques are also highlighted.

  16. Smartphone-Based Mobile Detection Platform for Molecular Diagnostics and Spatiotemporal Disease Mapping.

    Science.gov (United States)

    Song, Jinzhao; Pandian, Vikram; Mauk, Michael G; Bau, Haim H; Cherry, Sara; Tisi, Laurence C; Liu, Changchun

    2018-04-03

    Rapid and quantitative molecular diagnostics in the field, at home, and at remote clinics is essential for evidence-based disease management, control, and prevention. Conventional molecular diagnostics requires extensive sample preparation, relatively sophisticated instruments, and trained personnel, restricting its use to centralized laboratories. To overcome these limitations, we designed a simple, inexpensive, hand-held, smartphone-based mobile detection platform, dubbed "smart-connected cup" (SCC), for rapid, connected, and quantitative molecular diagnostics. Our platform combines bioluminescent assay in real-time and loop-mediated isothermal amplification (BART-LAMP) technology with smartphone-based detection, eliminating the need for an excitation source and optical filters that are essential in fluorescent-based detection. The incubation heating for the isothermal amplification is provided, electricity-free, with an exothermic chemical reaction, and incubation temperature is regulated with a phase change material. A custom Android App was developed for bioluminescent signal monitoring and analysis, target quantification, data sharing, and spatiotemporal mapping of disease. SCC's utility is demonstrated by quantitative detection of Zika virus (ZIKV) in urine and saliva and HIV in blood within 45 min. We demonstrate SCC's connectivity for disease spatiotemporal mapping with a custom-designed website. Such a smart- and connected-diagnostic system does not require any lab facilities and is suitable for use at home, in the field, in the clinic, and particularly in resource-limited settings in the context of Internet of Medical Things (IoMT).

  17. 3D-QSAR, molecular docking, and molecular dynamic simulations for prediction of new Hsp90 inhibitors based on isoxazole scaffold.

    Science.gov (United States)

    Abbasi, Maryam; Sadeghi-Aliabadi, Hojjat; Amanlou, Massoud

    2018-05-01

    Heat shock protein 90(Hsp90), as a molecular chaperone, play a crucial role in folding and proper function of many proteins. Hsp90 inhibitors containing isoxazole scaffold are currently being used in the treatment of cancer as tumor suppressers. Here in the present studies, new compounds based on isoxazole scaffold were predicted using a combination of molecular modeling techniques including three-dimensional quantitative structure-activity relationship (3D-QSAR), molecular docking and molecular dynamic (MD) simulations. Comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were also done. The steric and electrostatic contour map of CoMFA and CoMSIA were created. Hydrophobic, hydrogen bond donor and acceptor of CoMSIA model also were generated, and new compounds were predicted by CoMFA and CoMSIA contour maps. To investigate the binding modes of the predicted compounds in the active site of Hsp90, a molecular docking simulation was carried out. MD simulations were also conducted to evaluate the obtained results on the best predicted compound and the best reported Hsp90 inhibitors in the 3D-QSAR model. Findings indicate that the predicted ligands were stable in the active site of Hsp90.

  18. Molecular-based tumour subtypes of canine mammary carcinomas assessed by immunohistochemistry

    Directory of Open Access Journals (Sweden)

    Sarli Giuseppe

    2010-01-01

    Full Text Available Abstract Background Human breast cancer is classified by gene expression profile into subtypes consisting of two hormone (oestrogen and/or progesterone receptor-positive types (luminal-like A and luminal-like B and three hormone receptor-negative types [human epidermal growth factor receptor 2-expressing, basal-like, and unclassified ("normal-like"]. Immunohistochemical surrogate panels are also proposed to potentially identify the molecular-based groups. The present study aimed to apply an immunohistochemical panel (anti-ER, -PR, -ERB-B2, -CK 5/6 and -CK14 in a series of canine malignant mammary tumours to verify the molecular-based classification, its correlation with invasion and grade, and its use as a prognostic aid in veterinary practice. Results Thirty-five tumours with luminal pattern (ER+ and PR+ were subgrouped into 13 A type and 22 B type, if ERB-B2 positive or negative. Most luminal-like A and basal-like tumours were grade 1 carcinomas, while the percentage of luminal B tumours was higher in grades 2 and 3 (Pearson Chi-square P = 0.009. No difference in the percentage of molecular subtypes was found between simple and complex/mixed carcinomas (Pearson Chi-square P = 0.47. No significant results were obtained by survival analysis, even if basal-like tumours had a more favourable prognosis than luminal-like lesions. Conclusion The panel of antibodies identified only three tumour groups (luminal-like A and B, and basal-like in the dog. Even though canine mammary tumours may be a model of human breast cancer, the existence of the same carcinoma molecular subtypes in women awaits confirmation. Canine mammary carcinomas show high molecular heterogeneity, which would benefit from a classification based on molecular differences. Stage and grade showed independent associations with survival in the multivariate regression, while molecular subtype grouping and histological type did not show associations. This suggests that caution should be

  19. Friction in Carborane-Based Molecular Rotors Driven by Gas Flow or Electric Field: Classical Molecular Dynamics

    Czech Academy of Sciences Publication Activity Database

    Prokop, Alexandr; Vacek, Jaroslav; Michl, Josef

    2012-01-01

    Roč. 6, č. 3 (2012), s. 1901-1914 ISSN 1936-0851 R&D Projects: GA ČR GA203/09/1802; GA MŠk ME09020 Institutional research plan: CEZ:AV0Z40550506 Keywords : molecular rotors * molecular dynamics * potential energy barriers * friction * intramolecular vibrational redistribution Subject RIV: CC - Organic Chemistry Impact factor: 12.062, year: 2012

  20. Molecular dynamics based simulations to study the fracture strength of monolayer graphene oxide

    Science.gov (United States)

    Verma, Akarsh; Parashar, Avinash

    2018-03-01

    The aim of this article is to study the effects of functional groups such as hydroxyl, epoxide and carboxyl on the fracture toughness of graphene. These functional groups form the backbone of the intrinsic atomic structure of graphene oxide (GO). Molecular dynamics based simulations were performed in conjunction with reactive force field parameters to capture the Mode-I fracture toughness of functionalised graphene. Simulations were performed in stages, to study the effect of these functional groups, individually as well as all together on the fracture toughness of GO nanosheets. The molecular dynamics based simulations performed in this article helps us to conclude that the spatial distribution and concentration of functional groups significantly affects the fracture behavior of GO nanosheets.

  1. Modeling the relationship between body weight and energy intake: a molecular diffusion-based approach.

    Science.gov (United States)

    Gong, Zhejun; Gong, Zhefeng

    2012-06-29

    Body weight is at least partly controlled by the choices made by a human in response to external stimuli. Changes in body weight are mainly caused by energy intake. By analyzing the mechanisms involved in food intake, we considered that molecular diffusion plays an important role in body weight changes. We propose a model based on Fick's second law of diffusion to simulate the relationship between energy intake and body weight. This model was applied to food intake and body weight data recorded in humans; the model showed a good fit to the experimental data. This model was also effective in predicting future body weight. In conclusion, this model based on molecular diffusion provides a new insight into the body weight mechanisms. This article was reviewed by Dr. Cabral Balreira (nominated by Dr. Peter Olofsson), Prof. Yang Kuang and Dr. Chao Chen.

  2. Demonstration of molecular assembly on Si (100) for CMOS-compatible molecule-based electronic devices.

    Science.gov (United States)

    Gergel-Hackett, Nadine; Zangmeister, Christopher D; Hacker, Christina A; Richter, Lee J; Richter, Curt A

    2008-04-02

    In this work, we establish the potential of a UV-promoted direct attachment of alkanes with alcohol and thiol linkers to the silicon (100) surfaces for use in molecular electronic devices with increased potential for integration with existing CMOS technologies. Characterization of the self-assembled monolayers via Fourier transform infrared spectroscopy, spectroscopic ellipsometry, and X-ray photoemission spectroscopy shows that the films assembled on the Si (100) are comparable in quality, aliphatic monolayer coverage, and extent of substrate oxidation to those assembled on the more extensively studied Si (111) crystal face. Simple Si (100)-based electronic devices fabricated with the monolayers exhibited molecule-dependent electrical characteristics. These data highlight the effectiveness of the assembly on Si (100), the ability to fabricate enclosed Si (100)-based molecular devices, and the potential for the future integration of these devices with more conventional technologies.

  3. Cellulose acetate-based molecularly imprinted polymeric membrane for separation of vanillin and o-vanillin

    OpenAIRE

    Zhang,Chunjing; Zhong,Shian; Yang,Zhengpeng

    2008-01-01

    Cellulose acetate-based molecularly imprinted polymeric membranes were prepared using vanillin as template molecule. The microscopic structure of the resultant polymeric membranes was characterized by SEM and FTIR spectroscopy, and the selective binding properties and separation capacity of the membranes for vanillin and o-vanillin were tested with binding experiments and separate experiments, respectively. The results showed that the vanillin-imprinted polymeric membranes displayed higher bi...

  4. The Design of a Molecular Assembly Line Based on Biological Molecules

    Science.gov (United States)

    2003-06-01

    the biological molecules polyketide synthase and kinesin, and in some embodiments, may employ biomolecules like DNA as components of the system. The...and will demonstrate how one can construct a purely synthetic analogue of a polyketide synthase . 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF...scaffold in programmed assembly and molecular electronics. It is based on the principles of the biological molecules polyketide synthase and kinesin, and in

  5. MALDI mass spectrometry based molecular phenotyping of CNS glial cells for prediction in mammalian brain tissue

    DEFF Research Database (Denmark)

    Hanrieder, Jørg; Wicher, Grzegorz; Bergquist, Jonas

    2011-01-01

    and straightforward methodology for direct characterization of rodent CNS glial cells using MALDI-MS-based intact cell mass spectrometry (ICMS). This molecular phenotyping approach enables monitoring of cell growth stages, (stem) cell differentiation, as well as probing cellular responses towards different...... tracers for prediction of oligodendroglial and astroglial localization in brain tissue. The different cell type specific protein distributions in tissue were validated using immunohistochemistry. ICMS of intact neuroglia is a simple and straightforward approach for characterization and discrimination...

  6. Synthesis, spectroscopic characterization, antimicrobial evaluation and molecular docking study of novel triazine-quinazolinone based hybrids

    Science.gov (United States)

    Dinari, Mohammad; Gharahi, Fateme; Asadi, Parvin

    2018-03-01

    A new series of 1,3,5-triazine incorporating aromatic quinazolinone moieties as a potential antimicrobial agents is reported. The first chlorine group of the cyanuric chloride (1) was replaced by aniline and the second one was replaced by various aromatic amines. The prepared monochlorotriazine was allowed to react with hydrazine and subsequently it was reacted with 2-methyl-4H-benzo[1,3]oxazin-4-one to obtain novel triazine-quinazolinone based hybrids (9a-f). The chemical structure and purity of the hybrid compounds were evaluated by different techniques such as thin layer chromatography, melting point, Fourier-transform infrared (FTIR), 1H and 13C NMR spectra and elemental analysis. Antimicrobial activity of the hybrid compounds were study by three Gram-negative bacteria (Salmonella entritidis, Escherichia coli, Pseudomonas aeruginosa) and three Gram-positive bacteria (Staphylococcus aureus, Listeria monocitogenes, Bacillus subtilis) as well as Candida albicansas a yeast-like fungus using the serial broth dilution method. Among them, compound 9d with benzenesulfonamide group showed higher antimicrobial activity with a minimum inhibitory concentration (MIC) value of 16 μg/mL. Furthermore, compounds 5d, 9a and 9b showed good activity against several tested strains. In addition, docking simulation was perform to position best antibacterial compounds in to the S. aureus dihydrofolate reductase (DHFR) active site to determine the probable binding conformations.

  7. Feasibility study of molecular memory device based on DNA using methylation to store information

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Liming; Al-Dirini, Feras [Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville 3010 (Australia); Center for Neural Engineering (CfNE), The University of Melbourne, Carlton 3053 (Australia); National ICT Australia, The University of Melbourne, Parkville 3010 (Australia); Qiu, Wanzhi; Skafidas, Efstratios, E-mail: sskaf@unimelb.edu.au [Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville 3010 (Australia); Center for Neural Engineering (CfNE), The University of Melbourne, Carlton 3053 (Australia); Hossain, Faruque M. [Center for Neural Engineering (CfNE), The University of Melbourne, Carlton 3053 (Australia); Evans, Robin [Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville 3010 (Australia)

    2016-07-14

    DNA, because of its robustness and dense information storage capability, has been proposed as a potential candidate for next-generation storage media. However, encoding information into the DNA sequence requires molecular synthesis technology, which to date is costly and prone to synthesis errors. Reading the DNA strand information is also complex. Ideally, DNA storage will provide methods for modifying stored information. Here, we conduct a feasibility study investigating the use of the DNA 5-methylcytosine (5mC) methylation state as a molecular memory to store information. We propose a new 1-bit memory device and study, based on the density functional theory and non-equilibrium Green's function method, the feasibility of electrically reading the information. Our results show that changes to methylation states lead to changes in the peak of negative differential resistance which can be used to interrogate memory state. Our work demonstrates a new memory concept based on methylation state which can be beneficial in the design of next generation DNA based molecular electronic memory devices.

  8. Band-selective chemical exchange saturation transfer imaging with hyperpolarized xenon-based molecular sensors.

    Science.gov (United States)

    Meldrum, Tyler; Bajaj, Vikram S; Wemmer, David E; Pines, Alexander

    2011-12-01

    Molecular imaging based on saturation transfer in exchanging systems is a tool for amplified and chemically specific magnetic resonance imaging. Xenon-based molecular sensors are a promising category of molecular imaging agents in which chemical exchange of dissolved xenon between its bulk and agent-bound phases has been use to achieve sub-picomolar detection sensitivity. Control over the saturation transfer dynamics, particularly when multiple exchanging resonances are present in the spectra, requires saturation fields of limited bandwidth and is generally accomplished by continuous wave irradiation. We demonstrate instead how band-selective saturation sequences based on multiple pulse inversion elements can yield saturation bandwidth tuneable over a wide range, while depositing less RF power in the sample. We show how these sequences can be used in imaging experiments that require spatial-spectral and multispectral saturation. The results should be applicable to all CEST experiments and, in particular, will provide the spectroscopic control required for applications of arrays of xenon chemical sensors in microfluidic chemical analysis devices. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. Molecular phylogeny of Toxoplasmatinae: comparison between inferences based on mitochondrial and apicoplast genetic sequences

    Directory of Open Access Journals (Sweden)

    Michelle Klein Sercundes

    2016-03-01

    Full Text Available Abstract Phylogenies within Toxoplasmatinae have been widely investigated with different molecular markers. Here, we studied molecular phylogenies of the Toxoplasmatinae subfamily based on apicoplast and mitochondrial genes. Partial sequences of apicoplast genes coding for caseinolytic protease (clpC and beta subunit of RNA polymerase (rpoB, and mitochondrial gene coding for cytochrome B (cytB were analyzed. Laboratory-adapted strains of the closely related parasites Sarcocystis falcatula and Sarcocystis neurona were investigated, along with Neospora caninum, Neospora hughesi, Toxoplasma gondii (strains RH, CTG and PTG, Besnoitia akodoni, Hammondia hammondiand two genetically divergent lineages of Hammondia heydorni. The molecular analysis based on organellar genes did not clearly differentiate between N. caninum and N. hughesi, but the two lineages of H. heydorni were confirmed. Slight differences between the strains of S. falcatula and S. neurona were encountered in all markers. In conclusion, congruent phylogenies were inferred from the three different genes and they might be used for screening undescribed sarcocystid parasites in order to ascertain their phylogenetic relationships with organisms of the family Sarcocystidae. The evolutionary studies based on organelar genes confirm that the genusHammondia is paraphyletic. The primers used for amplification of clpC and rpoB were able to amplify genetic sequences of organisms of the genus Sarcocystisand organisms of the subfamily Toxoplasmatinae as well.

  10. Feasibility study of molecular memory device based on DNA using methylation to store information

    International Nuclear Information System (INIS)

    Jiang, Liming; Al-Dirini, Feras; Qiu, Wanzhi; Skafidas, Efstratios; Hossain, Faruque M.; Evans, Robin

    2016-01-01

    DNA, because of its robustness and dense information storage capability, has been proposed as a potential candidate for next-generation storage media. However, encoding information into the DNA sequence requires molecular synthesis technology, which to date is costly and prone to synthesis errors. Reading the DNA strand information is also complex. Ideally, DNA storage will provide methods for modifying stored information. Here, we conduct a feasibility study investigating the use of the DNA 5-methylcytosine (5mC) methylation state as a molecular memory to store information. We propose a new 1-bit memory device and study, based on the density functional theory and non-equilibrium Green's function method, the feasibility of electrically reading the information. Our results show that changes to methylation states lead to changes in the peak of negative differential resistance which can be used to interrogate memory state. Our work demonstrates a new memory concept based on methylation state which can be beneficial in the design of next generation DNA based molecular electronic memory devices.

  11. Genetic Diversity of Some Sweet Cherry Cultivars Based on Molecular Markers

    Directory of Open Access Journals (Sweden)

    Ioana Virginia Berindean

    2016-11-01

    Full Text Available Sweet cherry (Prunus avium L., originated around the Caspian and Black Sea, is an important fruit tree species of economic interest, and hence, breeding and conservation are requested (. Genetic analysis at the molecular level can be used effectively to study molecular polymorphism existing between intraspecific and interspecific tree species and phylogenetic relationships between them and their hybrids. The purpose of this study was to characterize and determine genetic relationships among the sweet cherry native genotypes belonging to Fruit Research & Development Station Bistrita, Romania, using RAPD markers. To eliminate the existence of possible synonyms from national romanian collection, we collect four Van cultivars, from four different national collection. For molecular analysis of the 16 varieties of sweet cherry were considered 13 RAPD primers selected from the literature. They were later used to determine the genetic variability at the molecular level using PAST program, and the dendrogram was generated based on Jaccard’s genetic distance. The dendrogram constructed by PAST software. The quantity and quality of the DNA obtained was suitable to achieve PCR amplification step. Only seven out of the 13 RAPD primers have generate polymorphic bands. The rest of seven were monomorphics. The most polymorphic primer was OPB10 which generated 11 bands from which 100% were polymorphic.Seven RAPD primers generated a high level of polymorphism which allowed to divide these cherry varieties into two groups according to their genetic geographical origin and the pedigree.

  12. Molecular phylogeny and evolution of Scomber (Teleostei: Scombridae) based on mitochondrial and nuclear DNA sequences

    Science.gov (United States)

    Cheng, Jiao; Gao, Tianxiang; Miao, Zhenqing; Yanagimoto, Takashi

    2011-03-01

    A molecular phylogenetic analysis of the genus Scomber was conducted based on mitochondrial (COI, Cyt b and control region) and nuclear (5S rDNA) DNA sequence data in multigene perspective. A variety of phylogenetic analytic methods were used to clarify the current taxonomic Classification and to assess phylogenetic relationships and the evolutionary history of this genus. The present study produced a well-resolved phylogeny that strongly supported the monophyly of Scomber. We confirmed that S. japonicus and S. colias were genetically distinct. Although morphologically and ecologically similar to S. colias, the molecular data showed that S. japonicus has a greater molecular affinity with S. australasicus, which conflicts with the traditional taxonomy. This phylogenetic pattern was corroborated by the mtDNA data, but incompletely by the nuclear DNA data. Phylogenetic concordance between the mitochondrial and nuclear DNA regions for the basal nodes Supports an Atlantic origin for Scomber. The present-day geographic ranges of the species were compared with the resultant molecular phylogeny derived from partition Bayesian analyses of the combined data sets to evaluate possible dispersal routes of the genus. The present-day geographic distribution of Scomber species might be best ascribed to multiple dispersal events. In addition, our results suggest that phylogenies derived from multiple genes and long sequences exhibited improved phylogenetic resolution, from which we conclude that the phylogenetic reconstruction is a reliable representation of the evolutionary history of Scomber.

  13. Synchrotron based mass spectrometry to investigate the molecular properties of mineral-organic associations

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Suet Yi; Kleber, Markus; Takahashi, Lynelle K.; Nico, Peter; Keiluweit, Marco; Ahmed, Musahid

    2013-04-01

    Soil organic matter (OM) is important because its decay drives life processes in the biosphere. Analysis of organic compounds in geological systems is difficult because of their intimate association with mineral surfaces. To date there is no procedure capable of quantitatively separating organic from mineral phases without creating artifacts or mass loss. Therefore, analytical techniques that can (a) generate information about both organic and mineral phases simultaneously and (b) allow the examination of predetermined high-interest regions of the sample as opposed to conventional bulk analytical techniques are valuable. Laser Desorption Synchrotron Postionization (synchrotron-LDPI) mass spectrometry is introduced as a novel analytical tool to characterize the molecular properties of organic compounds in mineral-organic samples from terrestrial systems, and it is demonstrated that when combined with Secondary Ion Mass Spectrometry (SIMS), can provide complementary information on mineral composition. Mass spectrometry along a decomposition gradient in density fractions, verifies the consistency of our results with bulk analytical techniques. We further demonstrate that by changing laser and photoionization energies, variations in molecular stability of organic compounds associated with mineral surfaces can be determined. The combination of synchrotron-LDPI and SIMS shows that the energetic conditions involved in desorption and ionization of organic matter may be a greater determinant of mass spectral signatures than the inherent molecular structure of the organic compounds investigated. The latter has implications for molecular models of natural organic matter that are based on mass spectrometric information.

  14. Antenna Controller Replacement Software

    Science.gov (United States)

    Chao, Roger Y.; Morgan, Scott C.; Strain, Martha M.; Rockwell, Stephen T.; Shimizu, Kenneth J.; Tehrani, Barzia J.; Kwok, Jaclyn H.; Tuazon-Wong, Michelle; Valtier, Henry; Nalbandi, Reza; hide

    2010-01-01

    The Antenna Controller Replacement (ACR) software accurately points and monitors the Deep Space Network (DSN) 70-m and 34-m high-efficiency (HEF) ground-based antennas that are used to track primarily spacecraft and, periodically, celestial targets. To track a spacecraft, or other targets, the antenna must be accurately pointed at the spacecraft, which can be very far away with very weak signals. ACR s conical scanning capability collects the signal in a circular pattern around the target, calculates the location of the strongest signal, and adjusts the antenna pointing to point directly at the spacecraft. A real-time, closed-loop servo control algorithm performed every 0.02 second allows accurate positioning of the antenna in order to track these distant spacecraft. Additionally, this advanced servo control algorithm provides better antenna pointing performance in windy conditions. The ACR software provides high-level commands that provide a very easy user interface for the DSN operator. The operator only needs to enter two commands to start the antenna and subreflector, and Master Equatorial tracking. The most accurate antenna pointing is accomplished by aligning the antenna to the Master Equatorial, which because of its small size and sheltered location, has the most stable pointing. The antenna has hundreds of digital and analog monitor points. The ACR software provides compact displays to summarize the status of the antenna, subreflector, and the Master Equatorial. The ACR software has two major functions. First, it performs all of the steps required to accurately point the antenna (and subreflector and Master Equatorial) at the spacecraft (or celestial target). This involves controlling the antenna/ subreflector/Master-Equatorial hardware, initiating and monitoring the correct sequence of operations, calculating the position of the spacecraft relative to the antenna, executing the real-time servo control algorithm to maintain the correct position, and

  15. SYNERGISTIC WOOD PRESERVATIVES FOR REPLACEMENT OF CCA

    Science.gov (United States)

    The objective of this project was to evaluate the potential synergistic combinations of environmentally-safe biocides as wood preservatives. These wood preservatives could be potential replacements for the heavy-metal based CCA.Didecyldimethylammonium chloride [DDAC] was...

  16. Digital logic circuit based on two component molecular systems of BSA and salen

    Science.gov (United States)

    Hai-Bin, Lin; Feng, Chen; Hong-Xu, Guo

    2018-02-01

    A new fluorescent molecular probe 1 was designed and constructed by combining bovine serum albumin (BSA) and N,N‧-bis(salicylidene)ethylenediamine (salen). Stimulated by Zn2 +, tris, or EDTAH2Na2, the distance between BSA and salen was regulated, which was accompanied by an obvious change in the fluorescence intensity at 350 or 445 nm based on Förster resonance energy transfer. Moreover, based on the encoding binary digits in these inputs and outputs applying positive logic conventions, a monomolecular circuit integrating one OR, three NOT, and three YES gates, was successfully achieved.

  17. AMPHIDINIUM REVISITED. I. REDEFINITION OF AMPHIDINIUM (DINOPHYCEAE) BASED ON CLADISTIC AND MOLECULAR PHYLOGENETIC ANALYSES

    DEFF Research Database (Denmark)

    Jørgensen, Mårten Flø; Murray, Shauna; Daugbjerg, Niels

    2004-01-01

    -deflected epicones formed a monophyletic clade that included the type species. Amphidinium species with other epicone types were found to be unrelated to this clade. The type species A. operculatum was identified based on general cell shape and size, position of a dark organelle previously defined as a stigma......, and origin of the sulcus. The description of A. elegans by Grell and Wohlfarth-Bottermann was found to be identical to it. A species fitting the original description of A. operculatum was cultured and included in the analyses. Based on cladistic and molecular analyses, it grouped together with all other...

  18. Issues concerning the use of hormone replacement therapy and risk of fracture: a population-based, nested case-control study.

    Science.gov (United States)

    Corrao, Giovanni; Zambon, Antonella; Nicotra, Federica; Conti, Valentino; Nappi, Rossella E; Merlino, Luca

    2008-01-01

    To investigate the effect of duration, how recently it has been used, and age at start of hormone replacement therapy (HRT) and the risk of bone fracture. A population-based, nested case-control study was conducted in Lombardia, Northern Italy. The 78,294 women aged 45-75 years who received at least one HRT prescription during 1998-2000 were followed until 2005. Cases were women who experienced bone fracture during follow-up. Up to six controls were randomly selected for each case from the cohort after matching for age and date of cohort entry. The odds ratio of fracture associated with the use of HRT was estimated by conditional logistic regression. One thousand one hundred and seventy-four cases and 6760 controls were included. Compared with women who took HRT for less than 2 months, those who were treated for more than 20 months had an odds ratio (OR) of 0.80 (95% confidence interval 0.65, 0.99). This risk reduction was still significant among current HRT users (OR 0.71, 95% CI 0.55, 0.90) and in women who began therapy at the age of 55-65 years (OR 0.63, 95% CI 0.42, 0.94) or 65-75 years (OR 0.56, 95% CI 0.32, 0.99). There was no statistical evidence of a protective effect for women who had stopped treatment more than 6 months previously or those who began HRT at the age of 45-55 years. HRT should be continued for long periods to achieve an optimal protection from fracture. The fracture reducing potential of HRT seems to disappear after a few months without treatment and might mainly act in women who begin therapy at older age.

  19. Development and Integration of an SSR-Based Molecular Identity Database into Sugarcane Breeding Program

    Directory of Open Access Journals (Sweden)

    Yong-Bao Pan

    2016-04-01

    Full Text Available Sugarcane breeding is very difficult and it takes 12 to 14 years to develop a new cultivar for commercial production. This is because sugarcane varieties are highly polyploid, inter-specific hybrids with 100 to 130 chromosomes that may vary across geographical areas. Other obstacles/constraints include the small size of flowers that may not synchronize but may self-pollinate, difficulty in distinguishing hybrids from self progenies, extreme (G × E interactive effect, and potential variety mis-identification during vegetative propagation and varietal exchange. To help cane breeders circumvent these constraints, a simple sequence repeats (SSR-based molecular identity database has been developed at the United States Department of Agriculture-Agricultural Research Service, Sugarcane Research Unit in Houma, LA. Since 2005, approximately 2000 molecular identities have been constructed for clones of sugarcane and related Saccharum species that cover geographical areas including Argentina, Australia, Bangladesh, China, Colombia, India, Mexico, Pakistan, South Africa, Thailand, USA (Louisiana, Florida, Texas, and Hawaii, and Venezuela. The molecular identity database is updated annually and has been utilized to: (1 provide molecular descriptors to newly registered cultivars; (2 identify in a timely fashion any mislabeled or unidentifiable clones from cross parents and field evaluation plots; (3 develop de novo clones of energy cane with S. spontaneum cytoplasm; (4 provide clone-specific fingerprint information for assessing cross quality and paternity of polycross; (5 determine genetic relatedness of parental clones; (6 select F1 hybrids from (elite × wild or (wild × elite crosses; and (7 investigate the inheritance of SSR markers in sugarcane. The integration of the molecular identity database into the sugarcane breeding program may improve the overall efficacy of cultivar development and commercialization.

  20. Fast screening of ketamine in biological samples based on molecularly imprinted photonic hydrogels

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Liang [Department of Forensic Science, People' s Public Security University of China, Beijing (China); Meng, Pinjia, E-mail: mengpinjia@163.com [Department of Forensic Science, People' s Public Security University of China, Beijing (China); Zhang, Qingqing; Wang, Yanji [Department of Forensic Science, People' s Public Security University of China, Beijing (China)

    2013-04-10

    Graphical abstract: A novel label-free colorimetric chemosensor: with the increase in the concentration of ketamine, the Bragg diffraction peak of MIPHs gradually shifted to the longer wavelength region. Accompanying the peak shift, the color change of MIPHs was also observed obviously: from green to red. Highlights: ► We developed the label-free colorimetric MIPHs for handy and fast screening of ketamine. ► The obvious color change of MIPHs was observed upon ketamine. ► The MIPHs exhibited good sensing abilities in an aqueous environment. ► The sensing mechanisms of the water-compatible MIPHs were investigated. ► The MIPHs were employed to screening ketamine in real biological samples. -- Abstract: A novel label-free colorimetric chemosensor was developed for handy and fast screening of ketamine with high sensitivity and specificity based on molecularly imprinted photonic hydrogels (MIPHs) that combined the colloidal-crystal with molecular imprinting technique. The unique inverse opal arrays with a thin polymer wall in which the imprinted nanocavities of ketamine moleculars distributed allowed high sensitive, quick responsive, specific detection of the target analyte, and good regenerating ability in an aqueous environment. Due to the hierarchical inverse opal structural characteristics, the specific ketamine molecular recognition process can induce obvious swelling of the MIPHs to be directly transferred into visually perceptible optical signal (change in color) which can be detected by the naked eye through Bragg diffractive shifts of ordered macroporous arrays. In order to enhance the recognition ability in aqueous environments, the MIPHs were designed as water-compatible and synthesized in a water–methanol system. The molecular recognition mechanisms were investigated. The proposed MIPHs were successfully employed to screen trace level ketamine in human urine and saliva samples, exhibiting high sensitivity, rapid response, and specificity in the

  1. Product Platform Replacements

    DEFF Research Database (Denmark)

    Sköld, Martin; Karlsson, Christer

    2012-01-01

    . To shed light on this unexplored and growing managerial concern, the purpose of this explorative study is to identify operational challenges to management when product platforms are replaced. Design/methodology/approach – The study uses a longitudinal field-study approach. Two companies, Gamma and Omega......Purpose – It is argued in this article that too little is known about product platforms and how to deal with them from a manager's point of view. Specifically, little information exists regarding when old established platforms are replaced by new generations in R&D and production environments...... distinguishing between platform replacement “height” and “width”. Seven groups of managerial measures for dealing with the issues are recommended. Originality/value – The study aims to contribute to the existing literature by taking a managers' perspective of product platform development. Its specific...

  2. Electron induced conformational changes of an imine-based molecular switch on a Au(111) surface

    Energy Technology Data Exchange (ETDEWEB)

    Lotze, Christian; Henningsen, Nils; Franke, Katharina; Schulze, Gunnar; Pascual, Jose Ignacio [Inst. f. Experimentalphysik, Freie Universitaet Berlin (Germany); Luo, Ying; Haag, Rainer [Inst. f. Organische Chemie, Freie Universitaet Berlin (Germany)

    2009-07-01

    Azobenzene-based molecules exhibit a cis-trans configurational photoisomerisation in solution. Recently, the adsorption properties of azobenzene derivatives have been investigated on different metal surfaces in order to explore the possible changes in the film properties induced by external stimuli. In azobenzene, the diazo-bridge is a key group for the isomerization process. Its interaction with a metal surface is dominated through the N lone-pair electrons, which reduces the efficiency of the conformational change. In order to reduce the molecule-surface interaction, we explore an alternative molecular architecture by substituting the diazo-bridge (-N=N-) of azobenzene by an imine-group (-N=CH-). We have investigated the imine-based compound para-carboxyl-di-benzene-imine (PCI) adsorbed on a Au(111) surface. The carboxylic terminations mediates the formation of strongly bonded molecular dimers, which align in ordered rows preferentially following the fcc regions of the Au(111) herringbone reconstruction. Low temperature scanning tunneling microscopy was used to induce conformational changes between trans and cis state of individual molecules in a molecular monolayer.

  3. Group Contribution Method-based Multi-objective Evolutionary Molecular Design

    Directory of Open Access Journals (Sweden)

    Dörgő Gyula

    2016-10-01

    Full Text Available The search for compounds exhibiting desired physical and chemical properties is an essential, yet complex problem in the chemical, petrochemical, and pharmaceutical industries. During the formulation of this optimization-based design problem two tasks must be taken into consideration: the automated generation of feasible molecular structures and the estimation of macroscopic properties based on the resultant structures. For this structural characteristic-based property prediction task numerous methods are available. However, the inverse problem, the design of a chemical compound exhibiting a set of desired properties from a given set of fragments is not so well studied. Since in general design problems molecular structures exhibiting several and sometimes conflicting properties should be optimized, we proposed a methodology based on the modification of the multi-objective Non-dominated Sorting Genetic Algorithm-II (NSGA-II. The originally huge chemical search space is conveniently described by the Joback estimation method. The efficiency of the algorithm was enhanced by soft and hard structural constraints, which expedite the search for feasible molecules. These constraints are related to the number of available groups (fragments, the octet rule and the validity of the branches in the molecule. These constraints are also used to introduce a special genetic operator that improves the individuals of the populations to ensure the estimation of the properties is based on only reliable structures. The applicability of the proposed method is tested on several benchmark problems.

  4. Cervical intervertebral disc replacement.

    Science.gov (United States)

    Cason, Garrick W; Herkowitz, Harry N

    2013-02-06

    Symptomatic adjacent-level disease after cervical fusion has led to the development and testing of several disc-replacement prostheses. Randomized controlled trials of cervical disc replacement (CDR) compared with anterior cervical discectomy and fusion (ACDF) have demonstrated at least equivalent clinical results for CDR with similar or lower complication rates. Biomechanical, kinematic, and radiographic studies of CDR reveal that the surgical level and adjacent vertebral level motion and center of rotation more closely mimic the native state. Lower intradiscal pressures adjacent to CDR may help decrease the incidence of adjacent spinal-level disease, but long-term follow-up is necessary to evaluate this theory.

  5. Culture- and molecular-based detection of swine-adapted Salmonella shed by avian scavengers.

    Science.gov (United States)

    Blanco, Guillermo; Díaz de Tuesta, Juan A

    2018-04-13

    Salmonella can play an important role as a disease agent in wildlife, which can then act as carriers and reservoirs of sanitary importance at the livestock-human interface. Transmission from livestock to avian scavengers can occur when these species consume contaminated carcasses and meat remains in supplementary feeding stations and rubbish dumps. We compared the performance of PCR-based detection with conventional culture-based methods to detect Salmonella in the faeces of red kites (Milvus milvus) and griffon vultures (Gyps fulvus) in central Spain. The occurrence of culturable Salmonella was intermediate in red kites (1.9%, n=52) and high in griffon vultures (26.3%, n=99). These proportions were clearly higher with PCR-based detection (13.5% and 40.4%, respectively). Confirmation cultures failed to grow Salmonella in all faecal samples positive by the molecular assay but negative by the initial conventional culture in both scavenger species, indicating the occurrence of false (non-culturable) positives by PCR-based detection. This suggests that the molecular assay is highly sensitive to detecting viable Salmonella in cultures, but also partial genomes and dead or unviable bacteria from past infections or contamination. Thus, the actual occurrence of Salmonella in a particular sampling time period can be underestimated when using only culture detection. The serovars found in the scavenger faeces were among the most frequently isolated in pigs from Spain and other EU countries, especially those generally recognized as swine-adapted monophasic variants of S. Typhimurium. Because the studied species obtain much of their food from pig carcasses, this livestock may be the primary source of Salmonella via direct ingestion of infected carcasses and indirectly via contamination due to the unsanitary conditions found in supplementary feeding stations established for scavenger conservation. Combining culture- and molecular-based detection is encouraged to understand the

  6. Method and refrigerants for replacing existing refrigerants in centrifugal compressors

    International Nuclear Information System (INIS)

    Kopko, W.L.

    1991-01-01

    This patent describes a method for replacing an existing refrigerant in a centrifugal compressor. It comprises selecting a desired impeller Mach number for the centrifugal compressor; selecting a base refrigerant constituent; combining at least one additive refrigerant constituent with the base refrigerant constituent to form a replacement refrigerant having at least one physical or chemical property different from the existing refrigerant and substantially providing the desired impeller Mach number in the centrifugal compressor; and replacing the existing refrigerant with the replacement refrigerant

  7. Sequence-Specific β-Peptide Synthesis by a Rotaxane-Based Molecular Machine.

    Science.gov (United States)

    De Bo, Guillaume; Gall, Malcolm A Y; Kitching, Matthew O; Kuschel, Sonja; Leigh, David A; Tetlow, Daniel J; Ward, John W

    2017-08-09

    We report on the synthesis and operation of a three-barrier, rotaxane-based, artificial molecular machine capable of sequence-specific β-homo (β 3 ) peptide synthesis. The machine utilizes nonproteinogenic β 3 -amino acids, a class of amino acids not generally accepted by the ribosome, particularly consecutively. Successful operation of the machine via native chemical ligation (NCL) demonstrates that even challenging 15- and 19-membered ligation transition states are suitable for information translation using this artificial molecular machine. The peptide-bond-forming catalyst region can be removed from the transcribed peptide by peptidases, artificial and biomachines working in concert to generate a product that cannot be made by either machine alone.

  8. Surface plasmon resonance based optical fiber riboflavin sensor by using molecularly imprinted gel

    Science.gov (United States)

    Verma, Roli; Gupta, Banshi D.

    2013-05-01

    We report the fabrication and characterization of surface plasmon resonance (SPR) based optical fiber riboflavin/vitamin B2 sensor using combination of colloidal crystal templating and molecularly imprinted gel. The sensor works on spectral interrogation method. The operating range of the sensor lies from 0 μg/ml to 320 μg/ml, the suitable amount of intakes of riboflavin recommended for different age group. The SPR spectra show blue shift with increasing concentration of riboflavin, which is due to the interaction of riboflavin molecule over specific binding sites caused by molecular imprinting. The present sensor has many advantageous features such as fast response, small probe size, low cost and can be used for remote/online monitoring.

  9. Electrochemical sensor for dopamine based on a novel graphene-molecular imprinted polymers composite recognition element

    DEFF Research Database (Denmark)

    Mao, Yan; Bao, Yu; Gan, Shiyu

    2011-01-01

    A novel composite of graphene sheets/Congo red-molecular imprinted polymers (GSCR-MIPs) was synthesized through free radical polymerization (FRP) and applied as a molecular recognition element to construct dopamine (DA) electrochemical sensor. The template molecules (DA) were firstly absorbed...... at the GSCR surface due to their excellent affinity, and subsequently, selective copolymerization of methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA) was further achieved at the GSCR surface. Potential scanning was presented to extract DA molecules from the imprinted polymers film...... for highly sensitive and selective detection of DA was successfully constructed as demonstration based on the synthesized GSCR-MIPs nanocomposites. Under experimental conditions, selective detection of DA in a linear concentration range of 1.0×10−7–8.3×10−4M was obtained, which revealed a lower limit...

  10. A DNA-based molecular motor that can navigate a network of tracks.

    Science.gov (United States)

    Wickham, Shelley F J; Bath, Jonathan; Katsuda, Yousuke; Endo, Masayuki; Hidaka, Kumi; Sugiyama, Hiroshi; Turberfield, Andrew J

    2012-01-22

    Synthetic molecular motors can be fuelled by the hydrolysis or hybridization of DNA. Such motors can move autonomously and programmably, and long-range transport has been observed on linear tracks. It has also been shown that DNA systems can compute. Here, we report a synthetic DNA-based system that integrates long-range transport and information processing. We show that the path of a motor through a network of tracks containing four possible routes can be programmed using instructions that are added externally or carried by the motor itself. When external control is used we find that 87% of the motors follow the correct path, and when internal control is used 71% of the motors follow the correct path. Programmable motion will allow the development of computing networks, molecular systems that can sort and process cargoes according to instructions that they carry, and assembly lines that can be reconfigured dynamically in response to changing demands.

  11. Molecular characterisation of lumpy skin disease virus and sheeppox virus based on P32 gene

    Directory of Open Access Journals (Sweden)

    P.M.A.Rashid

    2017-06-01

    Full Text Available Lumpy skin disease virus (LSDV and sheeppox virus (SPV have a considerable economic impact on the cattle and small ruminant industry. They are listed in group A of contagious disease by the World Organization for Animal Health (OIE. This study addressed molecular characterisation of first LSDV outbreak and an endemic SPV in Kurdistan region of Iraq based on P32 gene. The results indicated that P32 gene can be successfully used for diagnosis of LSDV. The phylogenic and molecular analysis showed that there may be a new LSDV isolate circulating in Kurdistan which uniquely shared the same characteristic amino acid sequence with SPV and GPV, leucine at amino acid position 51 in P32 gene as well as few genetically distinct SPV causing pox disease in Kurdistan sheep. This study provided sequence information of P32 gene for several LSDV isolates, which positively affects the epidemiological study of Capripoxvirus

  12. Determination of Quantum Chemistry Based Force Fields for Molecular Dynamics Simulations of Aromatic Polymers

    Science.gov (United States)

    Jaffe, Richard; Langhoff, Stephen R. (Technical Monitor)

    1995-01-01

    Ab initio quantum chemistry calculations for model molecules can be used to parameterize force fields for molecular dynamics simulations of polymers. Emphasis in our research group is on using quantum chemistry-based force fields for molecular dynamics simulations of organic polymers in the melt and glassy states, but the methodology is applicable to simulations of small molecules, multicomponent systems and solutions. Special attention is paid to deriving reliable descriptions of the non-bonded and electrostatic interactions. Several procedures have been developed for deriving and calibrating these parameters. Our force fields for aromatic polyimide simulations will be described. In this application, the intermolecular interactions are the critical factor in determining many properties of the polymer (including its color).

  13. Successful Treatment of Advanced Metastatic Prostate Cancer following Chemotherapy Based on Molecular Profiling

    Directory of Open Access Journals (Sweden)

    Charles E. Myers

    2012-03-01

    Full Text Available After Taxotere fails, treatment options for metastatic prostate cancer are limited. The three drugs with FDA approval in this setting, Jevtana, Provenge and Zytiga, are associated with median survivals of less than 2 years. In part, the impact on survival is the result of low response rates, indicating a significant proportion of patients exhibiting de novo resistance to these agents. An alternate approach is to let treatment selection be governed by gene expression profiling so that the treatment is tailored to the specific patient. Here, we report a case of metastatic prostate cancer with a dramatic response to treatment selected based on molecular profiling. This patient had failed LHRH agonist, bicalutamide, Taxotere, and doxorubicin. Molecular profiling showed overexpression of the androgen receptor and he had a dramatic response of measurable disease to second-line hormonal therapy with ketoconazole, estrogen and Leukine.

  14. A WAO - ARIA - GA2LEN consensus document on molecular-based allergy diagnostics

    DEFF Research Database (Denmark)

    Canonica, Giorgio Walter; Ansotegui, Ignacio J; Pawankar, Ruby

    2013-01-01

    Molecular-based allergy (MA) diagnostics is an approach used to map the allergen sensitization of a patient at a molecular level, using purified natural or recombinant allergenic molecules (allergen components) instead of allergen extracts. Since its introduction, MA diagnostics has increasingly...... entered routine care, with currently more than 130 allergenic molecules commercially available for in vitro specific IgE (sIgE) testing.MA diagnostics allows for an increased accuracy in allergy diagnosis and prognosis and plays an important role in three key aspects of allergy diagnosis: (1) resolving...... and the need for food challenge testing; and (3) identifying patients and triggering allergens for specific immunotherapy (SIT).Singleplex and multiplex measurement platforms are available for MA diagnostics. The Immuno-Solid phase Allergen Chip (ISAC) is the most comprehensive platform currently available...

  15. Friction in carborane-based molecular rotors driven by gas flow or electric field: classical molecular dynamics.

    Science.gov (United States)

    Prokop, Alexandr; Vacek, Jaroslav; Michl, Josef

    2012-03-27

    Friction in molecular rotors is examined by classical molecular dynamics simulations for grid-mounted azimuthal dipolar molecular rotors, whose rotation is either allowed to decay freely or is driven at GHz frequencies by a flow of rare gas or by a rotating electric field. The rotating parts (rotators) are propeller-shaped. Their two to six blades consist of condensed aromatic rings and are attached to a deltahedral carborane hub, whose antipodal carbons carry [n]staffane axles mounted on a square molecular grid. The dynamic friction constant η has been derived in several independent ways with similar results. Analysis of free rotation decay yields η as a continuous exponentially decreasing function of rotor frequency. The calculated dependence of friction torque on frequency resembles the classical macroscopic Stribeck curve. Its relation to rotational potential energy barriers and the key role of the rate of intramolecular vibrational redistribution (IVR) of energy and angular momentum from rotator rotation to other modes are considered in two limiting regimes. (i) In the strongly overdamped regime, rotation is much slower than IVR, and effective friction can be expressed through potential barriers to rotation. (ii) In the strongly underdamped regime, rotation is much faster than IVR, whose rate then determines friction. © 2012 American Chemical Society

  16. Molecular diversification of Trichuris spp. from Sigmodontinae (Cricetidae) rodents from Argentina based on mitochondrial DNA sequences.

    Science.gov (United States)

    Callejón, Rocío; Robles, María Del Rosario; Panei, Carlos Javier; Cutillas, Cristina

    2016-08-01

    A molecular phylogenetic hypothesis is presented for the genus Trichuris based on sequence data from mitochondrial cytochrome c oxidase 1 (cox1) and cytochrome b (cob). The taxa consisted of nine populations of whipworm from five species of Sigmodontinae rodents from Argentina. Bayesian Inference, Maximum Parsimony, and Maximum Likelihood methods were used to infer phylogenies for each gene separately but also for the combined mitochondrial data and the combined mitochondrial and nuclear dataset. Phylogenetic results based on cox1 and cob mitochondrial DNA (mtDNA) revealed three clades strongly resolved corresponding to three different species (Trichuris navonae, Trichuris bainae, and Trichuris pardinasi) showing phylogeographic variation, but relationships among Trichuris species were poorly resolved. Phylogenetic reconstruction based on concatenated sequences had greater phylogenetic resolution for delimiting species and populations intra-specific of Trichuris than those based on partitioned genes. Thus, populations of T. bainae and T. pardinasi could be affected by geographical factors and co-divergence parasite-host.

  17. Nanomedicine-based combination anticancer therapy between nucleic acids and small-molecular drugs.

    Science.gov (United States)

    Huang, Wei; Chen, Liqing; Kang, Lin; Jin, Mingji; Sun, Ping; Xin, Xin; Gao, Zhonggao; Bae, You Han

    2017-06-01

    Anticancer therapy has always been a vital challenge for the development of nanomedicine. Repeated single therapeutic agent may lead to undesirable and severe side effects, unbearable toxicity and multidrug resistance due to complex nature of tumor. Nanomedicine-based combination anticancer therapy can synergistically improve antitumor outcomes through multiple-target therapy, decreasing the dose of each therapeutic agent and reducing side effects. There are versatile combinational anticancer strategies such as chemotherapeutic combination, nucleic acid-based co-delivery, intrinsic sensitive and extrinsic stimulus combinational patterns. Based on these combination strategies, various nanocarriers and drug delivery systems were engineered to carry out the efficient co-delivery of combined therapeutic agents for combination anticancer therapy. This review focused on illustrating nanomedicine-based combination anticancer therapy between nucleic acids and small-molecular drugs for synergistically improving anticancer efficacy. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Molecular dynamics simulation based on the multi-component molecular orbital method: Application to H5O2+,D5O2+,andT5O2+

    International Nuclear Information System (INIS)

    Ishimoto, Takayoshi; Koyama, Michihisa

    2012-01-01

    Graphical abstract: Molecular dynamics method based on multi-component molecular orbital method was applied to basic hydrogen bonding systems, H 5 O 2 + , and its isotopomers (D 5 O 2 + andT 5 O 2 + ). Highlights: ► Molecular dynamics method with nuclear quantum effect was developed. ► Multi-component molecular orbital method was used as ab initio MO calculation. ► Developed method applied to basic hydrogen bonding system, H 5 O 2 + , and isotopomers. ► O ⋯ O vibrational stretching reflected to the distribution of protonic wavefunctions. ► H/D/T isotope effect was also analyzed. - Abstract: We propose a molecular dynamics (MD) method based on the multi-component molecular orbital (MC M O) method, which takes into account the quantum effect of proton directly, for the detailed analyses of proton transfer in hydrogen bonding system. The MC M O based MD (MC M O-MD) method is applied to the basic structures, H 5 O 2 + (called “Zundel ion”), and its isotopomers (D 5 O 2 + andT 5 O 2 + ). We clearly demonstrate the geometrical difference of hydrogen bonded O ⋯ O distance induced by H/D/T isotope effect because the O ⋯ O in H-compound was longer than that in D- or T-compound. We also find the strong relation between stretching vibration of O ⋯ O and the distribution of hydrogen bonded protonic wavefunction because the protonic wavefunction tends to delocalize when the O ⋯ O distance becomes short during the dynamics. Our proposed MC M O-MD simulation is expected as a powerful tool to analyze the proton dynamics in hydrogen bonding systems.

  19. Molecularly imprinted microparticles in lipid-based formulations for sustained release of donepezil.

    Science.gov (United States)

    Ruela, André Luís Morais; de Figueiredo, Eduardo Costa; de Araújo, Magali Benjamim; Carvalho, Flávia Chiva; Pereira, Gislaine Ribeiro

    2016-10-10

    Donepezil is a drug administered for Alzheimer's disease treatment, and it is a potential template molecule for imprinted microparticles. The precipitation polymerization technique allows the synthesis of spherical imprinted microparticles, and the intermolecular interactions among drug and molecularly imprinted polymers (MIPs) play a promising role for delineating drug delivery systems. Once that donepezil is a poorly-water soluble compound, lipid based-formulations (LBFs) may enhance its oral administration. Based on this, LBFs are useful vehicles to incorporate imprinted microparticles synthesized by precipitation polymerization. In these formulations, the drug dissolved in lipids is accessible to adsorbate in the polymers, and the hydrophobic environment of lipids increases the molecular recognition of MIPs. The formulations based on MIPs using pure oleic acid as vehicle prolong the in vitro release of donepezil up to several hours by a Fickian diffusion mechanism, and it provides a multiphasic release pattern related to the heterogeneity of the binding sites. The modulation of donepezil release from MIPs-based formulations using oil vehicles may contribute to decrease its side effects, possibly regulating its absorption rate in the gastrointestinal tract. These systems represent a novel technological platform to prolong the delivery not only for donepezil, but also for a variety of therapeutics. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Structural and molecular docking studies of biologically active mercaptopyrimidine Schiff bases

    Science.gov (United States)

    Kirubavathy, S. Jone; Velmurugan, R.; Karvembu, R.; Bhuvanesh, N. S. P.; Enoch, Israel V. M. V.; Selvakumar, P. Mosae; Premnath, D.; Chitra, S.

    2017-01-01

    Novel Schiff bases derived from the treatment of mercapto-diamino pyrimidine with two different aldehydes are characterized using elemental analysis, single crystal X-ray diffraction and 1H NMR spectroscopy. The pharmacological action of the synthesized compounds viz., antimicrobial, anticancer and antitubercular activities is studied. The Schiff bases show a very good activity against various test pathogens. DNA and β-CD binding interactions of the compounds are studied using UV-Visible absorption and fluorescence spectral measurements. The binding constants of the compounds towards β-CD are in the order of 103 to 104. Molecular docking is done using MOE program on the 3D structure of the enzymes, viz., human thymidylate synthase complexed with dump and raltitrex, candida albicans N-myristoyltransferasepeptidic inhibitor, catalytic domain of protein kinase pKnb from mycobacterium tuberculosis in complex with mitoxantrone, pare, topoisomerase atpase inhibitor, E. coli and lactobacillus casdihydrofolatereductase. The MIC/IC50 values of the Schiff bases are compared with the glide scores from the molecular docking studies. The number of hydrogen bonding interactions between the Schiff bases and amino acid residues are also reported.