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Sample records for molecular na homeostase

  1. Reflexo dos barorreceptores e homeostase da pressão arterial

    Directory of Open Access Journals (Sweden)

    Anderson Martelli

    2013-12-01

    Full Text Available A hipertensão arterial é considerada um dos principais fatores de risco para a morbidade e mortalidade cardiovascular. Os reflexos originados nos barorreceptores arteriais e nos receptores de estiramento da região cardiopulmonar são os principais mecanismos de controle efetivo da pressão arterial a curto prazo. O reflexo dos barorreceptores é considerado um sistema de controle de alto ganho, que mantém a pressão arterial dentro de limites normais em períodos de segundos a minutos. Dessa forma, esta revisão busca abordar os mecanismos desenvolvidos pelos barorreceptores na homeostase da pressão arterial. No presente artigo foram relatadas as alterações dos reflexos cardiovasculares na hipertensão arterial, focando a distribuição dos barorreceptores e seu funcionamento no restabelecimento da pressão arterial. Para realização desta pesquisa foi realizada uma revisão de artigos científicos utilizando as bases de dados Medline, Scielo e Lilacs. Adicionalmente foram consultados livros de fisiologia humana para complementação das informações sobre a fisiologia do barorreflexo na homeostase da pressão arterial. Estudos clínicos têm mostrado que uma reduzida sensibilidade do barorreflexo está associada com a morte súbita que se segue ao infarto agudo do miocárdio. O entendimento dos reflexos dos barorreceptores e a manutenção da hipertensão arterial em curto prazo são de grande importância para o entendimento da fisiopatogenia envolvidas no desenvolvimento e/ou evolução de determinadas alterações patológicas.

  2. Do ambiente aos genes : o uso de ferramentas bioinformáticas na procura de um mínimo denominador molecular e celular comum no espectro autista

    OpenAIRE

    Fares Zeidán-Chuliá

    2014-01-01

    O autismo pode ser definido como um transtorno associado ao desenvolvimento e caracterizado por prejuízo na interação social, na comunicação e no comportamento. Sua etiologia ainda é pouco conhecida, existindo alterações no desenvolvimento encefálico durante a embriogênese e na vida pós-natal. Sugere-se uma complexa interface entre fatores genéticos e ambientais. Existem provas que mostram uma desregulação do controle da homeostase e redes neuronais por parte de células astrogliais, ativação ...

  3. BASES MOLECULARES DA ABSORÇÃO DO FERRO

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    A. A. MACHADO

    2009-03-01

    Full Text Available

    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 proteínas, envolvidas na absorção intestinal do ferro não-heme, e progressos significativos foram feitos no entendimento da regulação da absorção intestinal do ferro, sendo identificadas várias moléculas candidatas. As bases moleculares da homeostase do ferro ainda não foram totalmente elucidadas, porém as informações já existentes sugerem que, em condições fisiológicas, a absorção, o transporte e o armazenamento sejam feitos por moléculas altamente especializadas e, em especial, a absorção, com mecanismos saturáveis em baixa concentração. No entanto, a absorção pode ocorrer por vias menos sujeitas ao controle, dependendo da sobrecarga e da natureza química do composto utilizado. Estas informações advogam a favor de uma revisão nas estratégias de combate à anemia ferropriva. PALAVRAS-CHAVE: Absorção do ferro; DMT-1; hepahestina; ceruloplasmina; ferroportina; hepcidina.

  4. A controllable molecular sieve for Na+ and K+ ions.

    Science.gov (United States)

    Gong, Xiaojing; Li, Jichen; Xu, Ke; Wang, Jianfeng; Yang, Hui

    2010-02-17

    The selective rate of specific ion transport across nanoporous material is critical to biological and nanofluidic systems. Molecular sieves for ions can be achieved by steric and electrical effects. However, the radii of Na(+) and K(+) are quite similar; they both carry a positive charge, making them difficult to separate. Biological ionic channels contain precisely arranged arrays of amino acids that can efficiently recognize and guide the passage of K(+) or Na(+) across the cell membrane. However, the design of inorganic channels with novel recognition mechanisms that control the ionic selectivity remains a challenge. We present here a design for a controllable ion-selective nanopore (molecular sieve) based on a single-walled carbon nanotube with specially arranged carbonyl oxygen atoms modified inside the nanopore, which was inspired by the structure of potassium channels in membrane spanning proteins (e.g., KcsA). Our molecular dynamics simulations show that the remarkable selectivity is attributed to the hydration structure of Na(+) or K(+) confined in the nanochannels, which can be precisely tuned by different patterns of the carbonyl oxygen atoms. The results also suggest that a confined environment plays a dominant role in the selectivity process. These studies provide a better understanding of the mechanism of ionic selectivity in the KcsA channel and possible technical applications in nanotechnology and biotechnology, including serving as a laboratory-in-nanotube for special chemical interactions and as a high-efficiency nanodevice for purification or desalination of sea and brackish water.

  5. Electronic structure and molecular dynamics of Na2Li

    Science.gov (United States)

    Malcolm, Nathaniel O. J.; McDouall, Joseph J. W.

    Following the first report (Mile, B., Sillman, P. D., Yacob, A. R. and Howard, J. A., 1996, J. chem. Soc. Dalton Trans , 653) of the EPR spectrum of the mixed alkali-metal trimer Na2Li a detailed study has been made of the electronic structure and structural dynamics of this species. Two isomeric forms have been found: one of the type, Na-Li-Na, of C , symmetry and another, Li-Na-Na, of C symmetry. Also, there are two linear saddle points which correspond to 'inversion' transition structures, and a saddle point of C symmetry which connects the two minima. A molecular dynamics investigation of these species shows that, at the temperature of the reported experiments (170 K), the C minimum is not 'static', but undergoes quite rapid inversion. At higher temperatures the C minimum converts to the C form, but by a mechanism very different from that suggested by minimum energy path considerations. 2 2v s s 2v 2v s

  6. Molecular dynamics investigation of Na+ in Na2Ni2TeO6

    International Nuclear Information System (INIS)

    Sau, Kartik; Kumar, P. Padma

    2014-01-01

    An inter-atomic potential for Na 2 Ni 2 TeO 6 in the Parrinello- Rahman-Vashishta (PRV) model is parameterized empirically. The potential reproduces variety of structural and transport properties of that material in good agreement with recent experimental results. The study provides fresh insights on the migration channels and mechanism of Na + in the system

  7. O papel de marcadores moleculares na genética forense

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    Daniele Decanine

    2016-07-01

    Full Text Available O objetivo desse trabalho foi apresentar uma revisão bibliográfica sobre as tecnologias utilizadas na Genética Forense, enfatizando o uso de marcadores moleculares para a identificação humana. Apresento aqui alguns exemplos do potencial da Biologia Molecular para auxiliar na investigação criminal, bem como na definição de parentesco (maternidade e paternidade. A utilização desses marcadores é atualmente a peça fundamental para os testes de DNA forense. Estes sistemas são, na sua maioria, baseados na análise de painéis de sequências microssatélites específicas (STRs. Foi possível discorrer sobre o uso forense do DNA, sobre a presença de regiões hipervariáveis no material genético, o papel de marcadores moleculares, bem como abordar técnicas de análise de DNA e suas aplicações. A busca por novas metodologias se faz importante para reduzir os custos e impulsionar uma nova cultura genética na Ciência Forense, as quais terão impacto no futuro do DNA forense com a expansão da Biologia Molecular.

  8. Molecular simulation of water removal from simple gases with zeolite NaA.

    Science.gov (United States)

    Csányi, Eva; Ható, Zoltán; Kristóf, Tamás

    2012-06-01

    Water vapor removal from some simple gases using zeolite NaA was studied by molecular simulation. The equilibrium adsorption properties of H(2)O, CO, H(2), CH(4) and their mixtures in dehydrated zeolite NaA were computed by grand canonical Monte Carlo simulations. The simulations employed Lennard-Jones + Coulomb type effective pair potential models, which are suitable for the reproduction of thermodynamic properties of pure substances. Based on the comparison of the simulation results with experimental data for single-component adsorption at different temperatures and pressures, a modified interaction potential model for the zeolite is proposed. In the adsorption simulations with mixtures presented here, zeolite exhibits extremely high selectivity of water to the investigated weakly polar/non-polar gases demonstrating the excellent dehydration ability of zeolite NaA in engineering applications.

  9. Ab initio effective core potentials for molecular calculations. Potentials for main group elements Na to Bi

    International Nuclear Information System (INIS)

    Wadt, W.R.; Hay, P.J.

    1985-01-01

    A consistent set of ab initio effective core potentials (ECP) has been generated for the main group elements from Na to Bi using the procedure originally developed by Kahn. The ECP's are derived from all-electron numerical Hartree--Fock atomic wave functions and fit to analytical representations for use in molecular calculations. For Rb to Bi the ECP's are generated from the relativistic Hartree--Fock atomic wave functions of Cowan which incorporate the Darwin and mass--velocity terms. Energy-optimized valence basis sets of (3s3p) primitive Gaussians are presented for use with the ECP's. Comparisons between all-electron and valence-electron ECP calculations are presented for NaF, NaCl, Cl 2 , Cl 2 - , Br 2 , Br 2 - , and Xe 2 + . The results show that the average errors introduced by the ECP's are generally only a few percent

  10. Molecular characterization of the Na+/H+-antiporter NhaA from Salmonella Typhimurium.

    Science.gov (United States)

    Lentes, Christopher J; Mir, Syed H; Boehm, Marc; Ganea, Constanta; Fendler, Klaus; Hunte, Carola

    2014-01-01

    functional studies to contribute to the elucidation of the mechanism of pH-dependent Na+/H+ antiporters and to provide insights in the molecular basis of species-specific growth and survival strategies.

  11. Effects of taurine supplementation and swimming, associated or not, on obesity and glucose homeostasis in mice = Efeito da suplementação com taurina e da natação, associadas ou não, sobre a obesidade e homeostase glicêmica em camundongos

    Directory of Open Access Journals (Sweden)

    Iris Cheng

    2012-10-01

    Full Text Available . Studies show that physical exercise (PE is associated with a reduced fat accumulation and increased insulin sensitivity, and taurine (TAU improves glucose homeostasis in lean rodents. The aim in this work was evaluate the effects of supplementing TAU and practice of PE, associated or not, on obesity and glucose homeostasis on obese MSG-mice. Neonate male Swiss mice received injections of monosodium glutamate (MSG group or saline (CON group. From the 30th to the 90th day of life, one group of animals received TAU in drinking water (MSG TAU group, another was subjected to PE (MSG PE group and a third group underwent both procedures (MSG PE TAU group. Mice treated with MSG become obese, hypertriglyceridemic, glucose intolerant and insulin resistant. The supplementation with TAU and the PE, isolated or associated, reduced the triglycerides (38%, glucose intolerance (around 30% and KITT (79% in MSG-obese animals, but did not influence the accumulation of fat. Interestingly, the combination of both strategies significantly reduced the insulin resistance, compared to animals subjected to isolated strategies. In conclusion, the supplementation with TAU and PE, isolated or associated, did not influence the accumulation of fat in MSG-obese mice, however, reduce the triglycerides and insulin resistance. O exercício físico (EF está associado à redução do acúmulo de gordura e aumento na sensibilidade à insulina e a taurina (TAU melhora a homeostase glicêmica em roedores magros. Objetivou-se avaliar os efeitos da suplementação com TAU e do EF, associados ou não, sobre a obesidade e a homeostase glicêmica em camundongos obesos-MSG. Camundongos Swiss machos neonatos receberam injeções de glutamato monossódico (grupo MSG ou salina (grupo CON. Do 30º ao 90º dia de vida, um grupo de animais MSG recebeu TAU na água de beber (MSG TAU; outro foi submetido ao EF (MSG EX e um terceiro grupo foi submetido aos dois procedimentos (MSG EX TAU

  12. Molecular Doping the Topological Dirac Semimetal Na3Bi across the Charge Neutrality Point with F4-TCNQ.

    Science.gov (United States)

    Edmonds, Mark T; Hellerstedt, Jack; O'Donnell, Kane M; Tadich, Anton; Fuhrer, Michael S

    2016-06-29

    We perform low-temperature transport and high-resolution photoelectron spectroscopy on 20 nm thin film topological Dirac semimetal Na3Bi grown by molecular beam epitaxy. We demonstrate efficient electron depletion ∼10(13) cm(-2) of Na3Bi via vacuum deposition of molecular F4-TCNQ without degrading the sample mobility. For samples with low as-grown n-type doping (1 × 10(12) cm(-2)), F4-TCNQ doping can achieve charge neutrality and even a net p-type doping. Photoelectron spectroscopy and density functional theory are utilized to investigate the behavior of F4-TCNQ on the Na3Bi surface.

  13. Structural analysis of molten Na2O-NaF-SiO2 system by Raman spectroscopy and molecular dynamics simulation

    International Nuclear Information System (INIS)

    Sasaki, Yasushi; Urata, Hidehiro; Ishii, Kuniyoshi

    2003-01-01

    To determine the effect of F ions on the structure of the molten alkali silicate systems, quenched Na 2 O-SiO 2 -NaF systems were investigated by Raman spectroscopy and molecular dynamics simulation. The systematic increase of 1100cm -1 band intensity in the Raman spectra of the silicate melts accompanying the replacement of O by F provides the evidence for concomitant polymerization of melts. From the molecular dynamics simulation, it was confirmed that most of substituted F was mainly coordinated to Na + ions but not Si 4+ ions at least up to 12.5 mol% of F ion content. A small amount of F was found to be coordinated to Si as a non-bridging ion from the molecular dynamics simulation, although there was no recognizable evidence from Raman Spectroscopy. These results were consistent with the mechanism in which F associated with otherwise network-modifying Na rather than with network-forming Si. Since F was associated to Na + ions, the replace of O ion by two F ions promote the polymerization of silicate melts. (author)

  14. NARROW Na AND K ABSORPTION LINES TOWARD T TAURI STARS: TRACING THE ATOMIC ENVELOPE OF MOLECULAR CLOUDS

    Energy Technology Data Exchange (ETDEWEB)

    Pascucci, I.; Simon, M. N. [Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721 (United States); Edwards, S. [Five College Astronomy Department, Smith College, Northampton, MA 01063 (United States); Heyer, M. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003-9305 (United States); Rigliaco, E. [Institute for Astronomy, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich (Switzerland); Hillenbrand, L. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Gorti, U.; Hollenbach, D., E-mail: pascucci@lpl.arizona.edu [SETI Institute, Mountain View, CA 94043 (United States)

    2015-11-20

    We present a detailed analysis of narrow Na i and K i absorption resonance lines toward nearly 40 T Tauri stars in Taurus with the goal of clarifying their origin. The Na i λ5889.95 line is detected toward all but one source, while the weaker K i λ7698.96 line is detected in about two-thirds of the sample. The similarity in their peak centroids and the significant positive correlation between their equivalent widths demonstrate that these transitions trace the same atomic gas. The absorption lines are present toward both disk and diskless young stellar objects, which excludes cold gas within the circumstellar disk as the absorbing material. A comparison of Na i and CO detections and peak centroids demonstrates that the atomic gas and molecular gas are not co-located, the atomic gas being more extended than the molecular gas. The width of the atomic lines corroborates this finding and points to atomic gas about an order of magnitude warmer than the molecular gas. The distribution of Na i radial velocities shows a clear spatial gradient along the length of the Taurus molecular cloud filaments. This suggests that absorption is associated with the Taurus molecular cloud. Assuming that the gradient is due to cloud rotation, the rotation of the atomic gas is consistent with differential galactic rotation, whereas the rotation of the molecular gas, although with the same rotation axis, is retrograde. Our analysis shows that narrow Na i and K i absorption resonance lines are useful tracers of the atomic envelope of molecular clouds. In line with recent findings from giant molecular clouds, our results demonstrate that the velocity fields of the atomic and molecular gas are misaligned. The angular momentum of a molecular cloud is not simply inherited from the rotating Galactic disk from which it formed but may be redistributed by cloud–cloud interactions.

  15. NARROW Na AND K ABSORPTION LINES TOWARD T TAURI STARS: TRACING THE ATOMIC ENVELOPE OF MOLECULAR CLOUDS

    International Nuclear Information System (INIS)

    Pascucci, I.; Simon, M. N.; Edwards, S.; Heyer, M.; Rigliaco, E.; Hillenbrand, L.; Gorti, U.; Hollenbach, D.

    2015-01-01

    We present a detailed analysis of narrow Na i and K i absorption resonance lines toward nearly 40 T Tauri stars in Taurus with the goal of clarifying their origin. The Na i λ5889.95 line is detected toward all but one source, while the weaker K i λ7698.96 line is detected in about two-thirds of the sample. The similarity in their peak centroids and the significant positive correlation between their equivalent widths demonstrate that these transitions trace the same atomic gas. The absorption lines are present toward both disk and diskless young stellar objects, which excludes cold gas within the circumstellar disk as the absorbing material. A comparison of Na i and CO detections and peak centroids demonstrates that the atomic gas and molecular gas are not co-located, the atomic gas being more extended than the molecular gas. The width of the atomic lines corroborates this finding and points to atomic gas about an order of magnitude warmer than the molecular gas. The distribution of Na i radial velocities shows a clear spatial gradient along the length of the Taurus molecular cloud filaments. This suggests that absorption is associated with the Taurus molecular cloud. Assuming that the gradient is due to cloud rotation, the rotation of the atomic gas is consistent with differential galactic rotation, whereas the rotation of the molecular gas, although with the same rotation axis, is retrograde. Our analysis shows that narrow Na i and K i absorption resonance lines are useful tracers of the atomic envelope of molecular clouds. In line with recent findings from giant molecular clouds, our results demonstrate that the velocity fields of the atomic and molecular gas are misaligned. The angular momentum of a molecular cloud is not simply inherited from the rotating Galactic disk from which it formed but may be redistributed by cloud–cloud interactions

  16. Molecular dynamics test of the Brownian description of Na+ motion in water

    International Nuclear Information System (INIS)

    Wilson, M.A.; Pohorille, A.; Pratt, L.R.

    1985-01-01

    The autocorrelation function of the velocity of an infinitely dilute Na + ion in aqueous solution, and the autocorrelation function of the force exerted on a stationary Na + under the same conditions are evaluated by molecular dynamics calculations. The results are used to test the accuracy of Brownian motion assumptions which are basic to hydrodynamic models of ion dynamics in solution. The self-diffusion coefficient of the Na + ion predicted by Brownian motion theory is (0.65 +- 0.1) x 10 -5 cm 2 /s. This value is about 60% greater than the one obtained for the proper dynamics of the finite mass ion, (0.4 +- 0.1) x 10 -5 cm 2 /s. The numerically correct velocity autocorrelation function is nonexponential, and the autocorrelation of the force on the stationary ion does not decay faster than the ion velocity autocorrelation function. Motivated by previous hydrodynamic modeling of friction kernels, we examine the approximation in which the memory function for the velocity autocorrelation function is identified with the autocorrelation function of the force on the stationary ion. The overall agreement between this approximation for the velocity autocorrelation function and the numerically correct answer is quite good

  17. Identification of Rice Accessions Associated with K+/Na+ Ratio and Salt Tolerance Based on Physiological and Molecular Responses

    Directory of Open Access Journals (Sweden)

    Inja Naga Bheema Lingeswara Reddy

    2017-11-01

    Full Text Available The key for rice plant survival under NaCl salt stress is maintaining a high K+/Na+ ratio in its cells. Selection for salt tolerance rice genotypes based on phenotypic performance alone will delay in progress in breeding. Use of molecular markers in tandem with physiological studies will help in better identification of salt tolerant rice accessions. Eight rice accessions along with the check Dongjin were screened using 1/2 Yoshida solution with 50 mmol/L NaCl at the seedling stage. The accessions IT001158, IT246674, IT260533 and IT291341 were classified as salt tolerant based on their K+/Na+ ratios. Seventeen SSR markers reported to be associated with K+/Na+ ratio were used to screen the accessions. Five SSR markers (RM8053, RM345, RM318, RM253 and RM7075 could differentiate accessions classified based on their K+/Na+ ratios. Banding pattern of the accessions was scored compared to the banding pattern of Dongjin. The study differentiated accessions based on their association of K+/Na+ ratio with molecular markers which are very reliable. These markers can play a significant role in screening large set of rice germplasms for salt tolerance and also help in identification of high-yielding varieties with better salt tolerance. The salt tolerant accessions can be taken forward into developing better varieties by conventional breeding and exploring genes for salt tolerance.

  18. Molecular dynamics simulations of the three-layer hydrate of Na-montmorillonite

    International Nuclear Information System (INIS)

    Holmboe, Michael; Bourg, Ian C.

    2012-01-01

    Document available in extended abstract form only. In many nuclear waste repositories concepts, compacted and smectite-rich bentonite clay is considered as an engineered transport barrier surrounding the canisters holding the nuclear waste. One of the requirements in the safety assessment of these repositories is to predict the transport rate of radionuclides as well as the overall hydraulic conductivity through the bentonite barrier. Kozaki and co-workers have obtained important information from diffusion experiments in bentonite on the mechanisms that control solute transport by studying the temperature-dependence of apparent diffusivity for solutes such as Na + , Cs + and Sr 2+ . Their results showed that the apparent diffusivity follows an Arrhenius relation (ln D a ∝ -E A /RT) with distinct activation energies of diffusion (E A ) for certain montmorillonite compactions, ionic strengths, and types of interlayer cation (Na + vs. Ca 2+ ). Their results suggest that solutes follow different diffusion pathways in compacted montmorillonite at different experimental conditions. In order to identify these transport pathways in compacted montmorillonite one needs independent knowledge of the relative abundance of the different types of interlayer nano-pores, i.e. the different coexisting hydration states (1W-3W), and of the molecular-scale EA for solute diffusion on the external basal surfaces of montmorillonite particles and in the interlayer nano-pores. The latter property can be obtained using molecular dynamics (MD) simulations, an important tool in the characterization of clays and clay minerals that yields detailed atomistic insights into the structural, dynamical and thermodynamic properties of many different geochemically relevant systems. In particular, MD simulations yield insight into the behavior of individual atoms, where most experimental methods only would probe the average behavior of large numbers of atoms or molecules. Thus, by simulating systems of

  19. Molecular dynamics simulations of the effect of NaCl-doping on the calcination characteristics in desulfurization processes

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, T.; Kurita, N.; Naruse, I. [Toyohashi University of Technology, Toyohashi (Japan)

    2003-03-01

    Desulfurization performance of wasted seashells was found to be over twice as high as that of limestone, which was currently used as a desulfurizer in fluidized bed coal combustors. NaCl-doping into limestone was also found to be effective in improving the desulfurization efficiency. From X-ray diffraction (XRD) analyses of calcined seashell, limestone and NaCl-doped limestone, on the other hand, not only the calcined seashell but also the NaCl-doped limestone had strong peaks of CaO crystal, and those two materials also had high desulfurization activity. This improvement was hypothesized to be due to NaCl causing a change in the crystal structure of CaO. In order to elucidate the effect of NaCl addition on the CaO crystal structure in the incineration of CaCO{sub 3} the change of structures was simulated by means of molecular dynamics simulations of CaO. In the simulation one molecule of NaCl was exchanged into one molecule of CaO. A pair correlation functions and the distances between Ca and O atoms, which were obtained by the simulations, were compared with those from the crystal CaO. NaCl-doping affected the crystalization temperature of CaO. The crystallization temperature increased due to adding a little bit of NaCl. From the result of the pair correlation functions obtained in NaCl-doped CaO, the difference of the potential energy of NaCl from that of CaO seemed to contribute to the crystallization of the bulk of CaO. The simulation and experimental results obtained suggested that NaCl-doping contributed to crystallizing the CaO molecules.

  20. Molecular dynamics of polarizable point dipole models for molten NaI. Comparison with first principles simulations

    Directory of Open Access Journals (Sweden)

    Trullàs J.

    2011-05-01

    Full Text Available Molecular dynamics simulations of molten NaI at 995 K have been carried out using polarizable ion models based on rigid ion pair potentials to which the anion induced dipole polarization is added. The polarization is added in such a way that point dipoles are induced on the anions by both local electric field and deformation short-range damping interactions that oppose the electrically induced dipole moments. The structure and self-diffusion results are compared with those obtained by Galamba and Costa Cabral using first principles Hellmann-Feynman molecular dynamics simulations and using classical molecular dynamics of a shell model which allows only the iodide polarization

  1. Na(+)-D-glucose cotransporter in the kidney of Squalus acanthias: molecular identification and intrarenal distribution.

    Science.gov (United States)

    Althoff, Thorsten; Hentschel, Hartmut; Luig, Jutta; Schütz, Hendrike; Kasch, Myriam; Kinne, Rolf K-H

    2006-04-01

    Using primers against conserved regions of mammalian Na(+)-d-glucose cotransporters (SGLT), a cDNA was cloned from the kidney of spiny dogfish shark (Squalus acanthias). On the basis of comparison of amino acid sequence, membrane topology, and putative glycosylation and phosphorylation sites, the cDNA could be shown to belong to the family of sglt genes. Indeed, Na(+)-dependent d-glucose uptake could be demonstrated after expression of the gene in Xenopus laevis oocytes. In a dendrogram, the SGLT from shark kidney has a high homology to the mammalian SGLT2. Computer analysis revealed that the elasmobranch protein is most similar to the mammalian proteins in the transmembrane regions and contains already all the amino acids identified to be functionally important, suggesting early conservation during evolution. Extramembraneous loops show larger variations. This holds especially for loop 13, which has been implied as a phlorizin-binding domain. Antibodies were generated and the intrarenal distribution of the SGLT was studied in cryosections. In parallel, the nephron segments were identified by lectins. Positive immunoreactions were found in the proximal tubule in the early parts PIa and PIb and the late segment PIIb. The large PIIa segment of the proximal tubule showed no reaction. In contrast to the mammalian kidney also the late distal tubule, the collecting tubule, and the collecting duct showed immunoreactivity. The molecular information confirms previous vesicle studies in which a low affinity SGLT with a low stoichiometry has been observed and supports the notion of a similarity of the shark kidney SGLT to the mammalian SGLT2. Despite its presence in the late parts of the nephron, the absence of SGLT in the major part of the proximal tubule, the relatively low affinity, and in particular the low stoichiometry might explain the lack of a T(m) for d-glucose in the shark kidney.

  2. Molecular composition of vapor in the NaF-ZrF4 system

    International Nuclear Information System (INIS)

    Korenev, Yu.M.; Sidorov, L.N.; Rykov, A.N.; Novoselova, A.V.

    1980-01-01

    The NaF-ZrF 4 system is studied. It is established that Na 2 ZrF 6 , NaZrF 5 , (NaZrF 5 ) 2 , NaZr 2 F 9 complex molecules are present in the saturated vapor alongside with pure components. Partial pressures of all vapor components are determined. The values of partial pressure and evaporation heat have been used to calculate the vapor composition above the system; T-x and P-T projections of the phase diagram of the NaF-ZrF 4 system are plotted

  3. Ion association in concentrated NaCl brines from ambient to supercritical conditions: results from classical molecular dynamics simulations

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    Collings Matthew D

    2002-11-01

    Full Text Available Highly concentrated NaCl brines are important geothermal fluids; chloride complexation of metals in such brines increases the solubility of minerals and plays a fundamental role in the genesis of hydrothermal ore deposits. There is experimental evidence that the molecular nature of the NaCl–water system changes over the pressure–temperature range of the Earth's crust. A transition of concentrated NaCl–H2O brines to a "hydrous molten salt" at high P and T has been argued to stabilize an aqueous fluid phase in the deep crust. In this work, we have done molecular dynamic simulations using classical potentials to determine the nature of concentrated (0.5–16 m NaCl–water mixtures under ambient (25°C, 1 bar, hydrothermal (325°C, 1 kbar and deep crustal (625°C, 15 kbar conditions. We used the well-established SPCE model for water together with the Smith and Dang Lennard-Jones potentials for the ions (J. Chem. Phys., 1994, 100, 3757. With increasing temperature at 1 kbar, the dielectric constant of water decreases to give extensive ion-association and the formation of polyatomic (NanClmn-m clusters in addition to simple NaCl ion pairs. Large polyatomic (NanClmn-m clusters resemble what would be expected in a hydrous NaCl melt in which water and NaCl were completely miscible. Although ion association decreases with pressure, temperatures of 625°C are not enough to overcome pressures of 15 kbar; consequently, there is still enhanced Na–Cl association in brines under deep crustal conditions.

  4. Electron transfer in keV Li+-Na*(3p) collisions: Pt.2. Molecular basis model

    International Nuclear Information System (INIS)

    Machholm, M.; Courbin, C.

    1996-01-01

    The velocity dependence of state-to-state integral cross sections for electron transfer and excitation in Li + -Na(3s, 3p) collisions is studied in the 0.05-0.3 au velocity range using the impact parameter semi-classical method and a 28-state molecular orbital basis model including a common translation factor. The initial orbital alignment dependence of electron transfer is in fair agreement with recent experiments and with atomic orbital model calculations. The main electron transfer channel from Na*(3p) is to the Li*(2p) states. The integral cross sections from an aligned or oriented Na*(3p) state to an aligned or oriented Li*(2p) state and vice versa and the corresponding alignment and orientation parameters are presented as a function of the impact velocity. (author)

  5. Structural Analysis of Molten NaNO3 by Molecular Dynamics Simulation

    Science.gov (United States)

    Tahara, Shuta; Toyama, Hiroshi; Shimakura, Hironori; Fukami, Takanori

    2017-08-01

    MD simulation for molten NaNO3 has been performed by using the Born-Mayer-Huggins-type potentials. The new structural features of molten NaNO3 are investigated by several analytical methods. The coordination-number and bond-angle distributions are similar to those of simple molten salts such as NaCl except for the variation caused by the different size of the anion and cation. Na+ ions are attracted toward O- ions, and get separated from N+ ions by Coulomb interactions. The distribution of the dihedral angle between NO3 - plannar ionic molecules has also been investigated.

  6. Distinctly Different Glass Transition Behaviors of Trehalose Mixed with Na2HPO 4 or NaH 2PO 4: Evidence for its Molecular Origin.

    Science.gov (United States)

    Weng, Lindong; Elliott, Gloria D

    2015-07-01

    The present study is aimed at understanding how the interactions between sugar molecules and phosphate ions affect the glass transition temperature of their mixtures, and the implications for pharmaceutical formulations. The glass transition temperature (Tg) and the α-relaxation temperature (Tα) of dehydrated trehalose/sodium phosphate mixtures (monobasic or dibasic) were determined by differential scanning calorimetry and dynamic mechanical analysis, respectively. Molecular dynamics simulations were also conducted to investigate the microscopic interactions between sugar molecules and phosphate ions. The hydrogen-bonding characteristics and the self-aggregation features of these mixtures were quantified and compared. Thermal analysis measurements demonstrated that the addition of NaH2PO4 decreased both the glass transition temperature and the α-relaxation temperature of the dehydrated trehalose/NaH2PO4 mixture compared to trehalose alone while both Tg and Tα were increased by adding Na2HPO4 to pure trehalose. The hydrogen-bonding interactions between trehalose and HPO4(2-) were found to be stronger than both the trehalose-trehalose hydrogen bonds and those formed between trehalose and H2PO4(-). The HPO4(2-) ions also aggregated into smaller clusters than H2PO4(-) ions. The trehalose/Na2HPO4 mixture yielded a higher T g than pure trehalose because marginally self-aggregated HPO4(2-) ions established a strengthened hydrogen-bonding network with trehalose molecules. In contrast H2PO4(-) ions served only as plasticizers, resulting in a lower Tg of the mixtures than trehalose alone, creating large-sized ionic pockets, weakening interactions, and disrupting the original hydrogen-bonding network amongst trehalose molecules.

  7. The human Na+-glucose cotransporter is a molecular water pump

    DEFF Research Database (Denmark)

    Meinild, A; Klaerke, D A; Loo, D D

    1998-01-01

    1. The human Na+-glucose cotransporter (hSGLT1) was expressed in Xenopus laevis oocytes. The transport activity, given by the Na+ current, was monitored as a clamp current and the concomitant flux of water followed optically as the change in oocyte volume. 2. When glucose was added to the bathing...... solution there was an abrupt increase in clamp current and an immediate swelling of the oocyte. The transmembrane transport of two Na+ ions and one sugar molecule was coupled, within the protein itself, to the influx of 210 water molecules. 3. This stoichiometry was constant and independent of the external...... parameters: Na+ concentrations, sugar concentrations, transmembrane voltages, temperature and osmotic gradients. 4. The cotransport of water occurred in the presence of adverse osmotic gradients. In accordance with the Gibbs equation, energy was transferred within the protein from the downhill fluxes of Na...

  8. [Comparison of manual and automated (MagNA Pure) nucleic acid isolation methods in molecular diagnosis of HIV infections].

    Science.gov (United States)

    Alp, Alpaslan; Us, Dürdal; Hasçelik, Gülşen

    2004-01-01

    Rapid quantitative molecular methods are very important for the diagnosis of human immunodeficiency virus (HIV) infections, assessment of prognosis and follow up. The purpose of this study was to compare and evaluate the performances of conventional manual extraction method and automated MagNA Pure system, for the nucleic acid isolation step which is the first and most important step in molecular diagnosis of HIV infections. Plasma samples of 35 patients in which anti-HIV antibodies were found as positive by microparticule enzyme immunoassay and confirmed by immunoblotting method, were included in the study. The nucleic acids obtained simultaneously by manual isolation kit (Cobas Amplicor, HIV-1 Monitor Test, version 1.5, Roche Diagnostics) and automated system (MagNA Pure LC Total Nucleic Acid Isolation Kit, Roche Diagnostics), were amplified and detected in Cobas Amplicor (Roche Diagnostics) instrument. Twenty three of 35 samples (65.7%) were found to be positive, and 9 (25.7%) were negative by both of the methods. The agreement between the methods were detected as 91.4%, for qualitative results. Viral RNA copies detected by manual and MagNA Pure isolation methods were found between 76.0-7.590.000 (mean: 487.143) and 113.0-20.300.0000 (mean: 2.174.097) copies/ml, respectively. When both of the overall and individual results were evaluated, the number of RNA copies obtained with automatized system, were found higher than the manual method (p<0.05). Three samples which had low numbers of nucleic acids (113, 773, 857, respectively) with MagNA Pure, yielded negative results with manual method. In conclusion, the automatized MagNA Pure system was found to be a reliable, rapid and practical method for the isolation of HIV-RNA.

  9. Uso da termografia infravermelha na análise da termorregulação de cavalo em treinamento

    OpenAIRE

    Moura,Daniella J. de; Maia,Ana Paula de A; Vercellino,Rimena do A; Medeiros,Brenda B. L; Sarubbi,Juliana; Griska,Paulo R

    2011-01-01

    O estresse térmico em equinos aciona mecanismos termorregulatórios, como mudanças no fluxo sanguíneo periférico, para a manutenção da homeostase corporal. A termografia infravermelha permite detectar estas alterações, sendo uma ferramenta útil para avaliar o estresse em animais. Assim, o objetivo deste estudo foi avaliar o uso da termografia infravermelha na termorregulação de equino em condição de treinamento. Foi utilizado um cavalo anglo-árabe, exercitado uma vez ao dia. Foram captadas ima...

  10. Protein kinase A (PKA) phosphorylation of Na+/K+-ATPase opens intracellular C-terminal water pathway leading to third Na+-binding site in molecular dynamics simulations

    DEFF Research Database (Denmark)

    Poulsen, Hanne; Nissen, Poul; Mouritsen, Ole G.

    2012-01-01

    -atom Molecular Dynamics (MD) simulations to investigate the structural consequences of phosphorylating the Na+/K+- ATPase (NKA) residue S936, which is the best characterized phosphorylation site in NKA, targeted in vivo by Protein Kinase A (PKA) (1-3). The MD simulations suggest that S936 phosphorylation opens......Phosphorylation is one of the major mechanisms for posttranscriptional modification of proteins. The addition of a compact, negatively charged moiety to a protein can significantly change its function and localization by affecting its structure and interaction network. We have used all...... a C-terminal hydrated pathway leading to D926, a transmembrane residue proposed to form part of the third sodium ion-binding site (4). Simulations of a S936E mutant form, for which only subtle effects are observed when expressed in Xenopus oocytes and studied with electrophysiology, does not mimic...

  11. Glucose-homeostase bij diabetes mellitus

    NARCIS (Netherlands)

    Oosten, Hessel Rienk

    1988-01-01

    In dit proefschrift worden enige aspecten van de glucosehomeostase bij type I (insuline afhankelijke) diabetes mellitus behandeld. Deze aspecten betreffen onder meer: het effect van verschillende glucosespiegels op de glucosebehoefte bij lage (±10 mE/m²/min) en verhoogde (30 mE/m²/min)

  12. Effect of thyroid status on the development of the different molecular forms of Na+,K+-ATPase in rat brain.

    Science.gov (United States)

    Atterwill, C K; Reid, J; Athayde, C M

    1985-05-01

    The effect of thyroid status on the postnatal development of the two molecular forms of Na+,K+-ATPase, distinguished kinetically on the basis of their ouabain sensitivity, was examined in rat brain. Hypothyroidism induced by PTU from day 1 postnatally significantly reduced the Na+,K+-ATPase activity in cerebellum (22-30 days) but not forebrain, whereas hyperthyroidism (T4 treatment from day 1) had no effect. The hypothyroidism-induced reduction in cerebellum was reflected by a 20-45% reduction in the activity of the alpha(+) form of Na+,K+-ATPase (high ouabain affinity) against control brains compared to a 60-70% reduction in the activity of the alpha form (low ouabain affinity). These results show that neonatally induced hypothyroidism leads to a selectively greater impairment of the ontogenesis of the activity of cerebellar alpha form of Na+,K+-ATPase. This may possibly reflect a retarded development of a selective cerebellar cell population containing predominantly the alpha form of the enzyme.

  13. Na,K-ATPase: a molecular target for Leptospira interrogans endotoxin

    Directory of Open Access Journals (Sweden)

    Younes-Ibrahim M.

    1997-01-01

    Full Text Available On the basis of our report that a glycolipoprotein fraction (GLP extracted from Leptospira interrogans contains a potent inhibitor of renal Na,K-ATPase, we proposed that GLP-induced inhibition of Na,K-ATPase might be the primary cellular defect in the physiopathology of leptospirosis. The present study was designed to test this hypothesis by determining whether or not 1 GLP inhibits all the isoforms of Na,K-ATPase which are expressed in the tissues affected by leptospirosis, 2 Na,K-ATPase from leptospirosis-resistant species, such as the rat, is sensitive to GLP, 3 GLP inhibits Na,K-ATPase from intact cells, and 4 GLP inhibits ouabain-sensitive H,K-ATPase. The results indicate that in the rabbit, a leptospirosis-sensitive species, GLP inhibits with similar efficiency (apparent IC50: 120-220 µg protein GLP/ml all isoforms of Na,K-ATPase known to be expressed in target tissues for the disease. Na,K-ATPase from rat kidney displays a sensitivity to GLP similar to that of the rabbit kidney enzyme (apparent IC50: 25-80 and 50-150 µg protein GLP/ml for rat and rabbit, respectively, indicating that resistance to the disease does not result from the resistance of Na,K-ATPase to GLP. GLP also reduces ouabain-sensitive rubidium uptake in rat thick ascending limbs (pmol mm-1 min-1 ± SEM; control: 23.8 ± 1.8; GLP, 88 µg protein/ml: 8.2 ± 0.9, demonstrating that it is active in intact cells. Finally, GLP had no demonstrable effect on renal H,K-ATPase activity, even on the ouabain-sensitive form, indicating that the active principle of GLP is more specific for Na,K-ATPase than ouabain itself. Although the hypothesis remains to be demonstrated in vivo, the present findings are compatible with the putative role of GLP-induced inhibition of Na,K-ATPase as an initial mechanism in the physiopathology of leptospirosis

  14. Separation of molecular hydrogen isotope mixtures using zeolite NaX-3M

    International Nuclear Information System (INIS)

    Polevoj, A.S.; Yudin, I.P.

    1984-01-01

    The components of transfer unit height (TUH) at separation of the H 2 -D 2 mixture using zeolite NaX-3M in the countercurrent column are determined. It is shown that the interphase isotopic exchange in the column is limited by gaseous diffusion in sorbent primary pores. On the basis of the TUH dependence the value of the hydrogen diffusion coefficient in primary pores of NaX-3M zeolite equal at 77 K and 87.3 K, respectively, approximately 1.09x10 -15 and approximately 1.69x10 -15 m 2 /s is calculated

  15. Levitation effect in zeolites: Quasielastic neutron scattering and molecular dynamics study of pentane isomers in zeolite NaY.

    Science.gov (United States)

    Borah, Bhaskar J; Jobic, H; Yashonath, S

    2010-04-14

    We report the quasielastic neutron scattering (QENS) and molecular dynamics (MD) investigations into diffusion of pentane isomers in zeolite NaY. The molecular cross section perpendicular to the long molecular axis varies for the three isomers while the mass and the isomer-zeolite interaction remains essentially unchanged. Both QENS and MD results show that the branched isomers neopentane and isopentane have higher self-diffusivities as compared with n-pentane at 300 K in NaY zeolite. This result provides direct experimental evidence for the existence of nonmonotonic, anomalous dependence of self-diffusivity on molecular diameter known as the levitation effect. The energetic barrier at the bottleneck derived from MD simulations exists for n-pentane which lies in the linear regime while no such barrier is seen for neopentane which is located clearly in the anomalous regime. Activation energy is in the order E(a)(n-pentane)>E(a)(isopentane)>E(a)(neopentane) consistent with the predictions of the levitation effect. In the liquid phase, it is seen that D(n-pentane)>D(isopentane)>D(neopentane) and E(a)(n-pentane)

  16. Molecular bond formation in Na* + N2 energy transfer: Crossed beam study of atomic alignment and orientation

    International Nuclear Information System (INIS)

    Reiland, W.; Jamieson, G.; Tittes, U.; Hertel, I.V.

    1982-01-01

    We report the first full analysis of collisionally induced atomic alignment and orientation for a molecular collision process. In an experiment with crossed supersonic beams of N 2 and laser excited Na(3 2 Psub(3/2)) we have studied the dependence of angular and energy resolved differential quenching cross sections as a function of the linear and circular polarization of the exciting laser light. The ansisotropies observed in the linear polarization data range up to 2:1 when corrected for electron and nuclear spin relaxation. The maximum effect is found at small scattering angles and intermediate energy transfer where the cross section is also largest. The atomic alignment angle most favourable for quenching relates to the scattering angle and can be understood in a model picture in such a way that the (NaN 2 )* molecular system is formed at internuclear distances as low as R = 10a 0 . The circular asymmetry is small but with significant structure and is attributed to interaction on different potential surfaces at R > 10a 0 . Full analysis of the four measurable parameter is given in terms of the density matrix in a frame with z-axis perpendicular to collision plane which allows a clear understanding of the properties of atomic reflection symmetry and coherence of the scattering process. (orig.)

  17. Marcadores moleculares na predição do sexo em plantas de mamoeiro Molecular markers for sex identification in papaya

    Directory of Open Access Journals (Sweden)

    Eder Jorge de Oliveira

    2007-12-01

    Full Text Available O objetivo deste trabalho foi validar marcadores moleculares, previamente identificados como ligados ao sexo do mamoeiro, para utilização na seleção indireta em genótipos comerciais. Foram analisadas duas variedades do grupo Solo e dois híbridos do grupo Formosa, com utilização de 20 plantas por genótipo, quatro marcadores do tipo SCAR (Sequence Characterized Amplified Region e um RAPD (Random Amplified Polymorphic DNA. O RAPD BC210 permitiu a identificação de todas as plantas femininas e hermafroditas, o que revela grande potencial para ser usado na seleção assistida em alguns dos genótipos mais cultivados no Brasil. Os marcadores do tipo SCAR não permitiram a identificação correta do sexo dos genótipos, pois detectou-se a presença de falso-positivos e falso-negativos nas análises.The objective of this work was the validation of previous discovered sex related molecular markers of papaya, aiming at the indirect selection of Brazilian commercial genotypes. Two varieties of the Solo group and two hybrids of the Formosa group (20 plants for genotype, four SCAR (Sequence Characterized Amplified Region and one RAPD (Random Amplified Polymorphic DNA markers were used. All hermaphrodite and female plants were correctly predicted by RAPD BC210, showing its high potential for marker assisted selection in important commercial genotypes used in Brazil. The SCAR markers did not show the true sex identification of these genotypes, revealing the presence of false positives and negatives in the analyses.

  18. Separation of molecular hydrogen isotope mixtures on zeolite NaX-3M

    International Nuclear Information System (INIS)

    Polevoj, A.S.; Yudin, I.P.

    1984-01-01

    The transfer unito height (TUH) have been determined at separation of the H 2 -D 2 mixture using zeolite NaX-3M depending on temperature and linear gas flow rate in the column. Experimentally the TUH value has been determined by the method of stepped variation of the concentration of one of the separated components at the entrance into the column and measurement of the substance front wash-out at the outlet. The results of determining TUH in the column of 10 mm diameter filled by the zeolite immobile layer with granules of 2-3 mm size show that with increasing the temperature from 77 K to 87.3 K TUH decreases while at constant temperature it increases with the growth of linear gas flow rate. The mentioned above circumstances testify to the essential contribution to the TUH value of the hydrogen diffusion process in the sorbent grain. The given TUH absolute values indicate the high rate of interphase isotope exchange at separation of the H 2 -D 2 mixture using NaX-3M zeolite

  19. Molecular Cloning and Functional Analysis of a Na+-Insensitive K+ Transporter of Capsicum chinense Jacq

    Science.gov (United States)

    Ruiz-Lau, Nancy; Bojórquez-Quintal, Emanuel; Benito, Begoña; Echevarría-Machado, Ileana; Sánchez-Cach, Lucila A.; Medina-Lara, María de Fátima; Martínez-Estévez, Manuel

    2016-01-01

    High-affinity K+ (HAK) transporters are encoded by a large family of genes and are ubiquitous in the plant kingdom. These HAK-type transporters participate in low- and high-affinity potassium (K+) uptake and are crucial for the maintenance of K+ homeostasis under hostile conditions. In this study, the full-length cDNA of CcHAK1 gene was isolated from roots of the habanero pepper (Capsicum chinense). CcHAK1 expression was positively regulated by K+ starvation in roots and was not inhibited in the presence of NaCl. Phylogenetic analysis placed the CcHAK1 transporter in group I of the HAK K+ transporters, showing that it is closely related to Capsicum annuum CaHAK1 and Solanum lycopersicum LeHAK5. Characterization of the protein in a yeast mutant deficient in high-affinity K+ uptake (WΔ3) suggested that CcHAK1 function is associated with high-affinity K+ uptake, with Km and Vmax for Rb of 50 μM and 0.52 nmol mg−1 min−1, respectively. K+ uptake in yeast expressing the CcHAK1 transporter was inhibited by millimolar concentrations of the cations ammonium (NH4+) and cesium (Cs+) but not by sodium (Na+). The results presented in this study suggest that the CcHAK1 transporter may contribute to the maintenance of K+ homeostasis in root cells in C. chinense plants undergoing K+-deficiency and salt stress. PMID:28083010

  20. Efeitos da administração in vivo do ácido fitânico sobre parâmetros de homeostase redox em cerebelo de ratos jovens

    OpenAIRE

    Clarissa Günther Borges

    2015-01-01

    O ácido fitânico (Fit) é um ácido graxo saturado de cadeia ramificada que se acumula em diversas doenças peroxissomais, como na síndrome de Zellweger (SZ) e particularmente na doença de Refsum (DR). Essas doenças podem ocorrer devido a defeitos na biogênese do peroxissomo ou em alguma proteína peroxisomal envolvida na β ou α-oxidação de ácidos graxos. Os pacientes afetados geralmente apresentam disfunções neurológicas, incluindo anormalidades cerebelares. Considerando que a patogênese das alt...

  1. Molecular detection and immunological localization of gill Na+/H+ exchanger in the dogfish (Squalus acanthias).

    Science.gov (United States)

    Claiborne, James B; Choe, Keith P; Morrison-Shetlar, Alison I; Weakley, Jill C; Havird, Justin; Freiji, Abe; Evans, David H; Edwards, Susan L

    2008-03-01

    The dogfish (Squalus acanthias) can make rapid adjustments to gill acid-base transfers to compensate for internal acidosis/alkalosis. Branchial Na+/H+ exchange (NHE) has been postulated as one mechanism driving the excretion of H+ following acidosis. We have cloned gill cDNA that includes an open reading frame coding for a 770-residue protein most homologous (approximately 71%) to mammalian NHE2. RT-PCR revealed NHE2 transcripts predominantly in gill, stomach, rectal gland, intestine, and kidney. In situ hybridization with an antisense probe against NHE2 in gill sections revealed a strong mRNA signal from a subset of interlamellar and lamellae cells. We developed dogfish-specific polyclonal antibodies against NHE2 that detected a approximately 70-kDa protein in Western blots and immunologically recognized branchial cells having two patterns of protein expression. Cytoplasmic and apical NHE2 immunoreactivity were observed in cells coexpressing basolateral Na+-K+-ATPase. Other large ovoid cells more generally staining for NHE2 also were strongly positive for basolateral H+-ATPase. Gill mRNA levels for NHE2 and H+-ATPase did not change following systemic acidosis (as measured by quantitative PCR 2 h after a 1- or 2-meq/kg acid infusion). These data indicate that posttranslational adjustments of NHE2 and other transport systems (e.g., NHE3) following acidosis may be of importance in the short-term pH adjustment and net branchial H+ efflux observed in vivo. NHE2 may play multiple roles in the gills, involved with H+ efflux from acid-secreting cells, basolateral H+ reabsorption for pHi regulation, and in parallel with H+-ATPase for the generation of HCO3(-) in base-secreting cells.

  2. Na/Ca Intermixing around Silicate and Phosphate Groups in Bioactive Phosphosilicate Glasses Revealed by Heteronuclear Solid-State NMR and Molecular Dynamics Simulations.

    Science.gov (United States)

    Mathew, Renny; Stevensson, Baltzar; Edén, Mattias

    2015-04-30

    We characterize the intermixing of network-modifying Na(+)/Ca(2+) ions around the silicate (QSi(n)) and phosphate (QP(n)) tetrahedra in a series of 16 Na2O–CaO–SiO2–P2O5 glasses, whose P content and silicate network connectivity were varied independently. The set includes both bioactive and bioinactive compositions and also encompasses two soda-lime-silicate members devoid of P, as well as two CaO–SiO2 glasses and one Na2O–SiO2–P2O5 glass. The various Si/P↔Na/Ca contacts were probed by molecular dynamics (MD) simulations together with heteronuclear magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) experimentation utilizing (23)Na{(31)P} and (23)Na{(29)Si} REDOR, as well as (31)P{ (23)Na} and (29)Si{(23)Na} REAPDOR. We introduce an approach for quantifying the extent of Na(+)/Ca(2+) ordering around a given QP(n) or QSi(n) group, encoded by the preference factor 0⩽ PM ⩽ 1 conveying the relative weights of a random cation intermixing (PM = 0) and complete preference/ordering (PM = 1) for one of the species M, which represents either Na(+) or Ca(2+). The MD-derived preference factors reveal phosphate and silicate species surrounded by Na(+)/Ca(2+) ions intermixed nearly randomly (PM ≲ 0.15), except for the QSi(4) and QSi(1) groups, which manifest more significant cation ordering with preference for Na+ and Ca2+, respectively. The overall weak preferences are essentially independent of the Si and P contents of the glass, whereas PM primarily correlates with the total amount of network modifiers: as the latter is increased, the Na/Ca distribution around the {QP(0), QSi(1), QSi(2)} groups with preference for Ca2(+ )tend to randomize (i.e., PCa decreases), while the PNa-values grow slightly for the {QP(1), QSi(3), QSi(4)} species already preferring coordination of Na. The set of experimental preference factors {PCa} for the orthophosphate (QP(0)) groups extracted from (31)P{(23)Na} REAPDOR NMR-derived M2(P–Na) dipolar second moments agrees

  3. Molecular dynamics simulations of Na+/Cl--dependent neurotransmitter transporters in a membrane-aqueous system

    DEFF Research Database (Denmark)

    Jørgensen, Anne Marie; Tagmose, L.; Jørgensen, A.M.M.

    2007-01-01

    We have performed molecular dynamics simulations of a homology model of the human serotonin transporter (hSERT) in a membrane environment and in complex with either the natural substrate S-HT or the selective serotonin reuptake inhibitor escitaloprom. We have also included a transporter homologue......, the Aquifex aeolicus leucine transporter (LeuT), in our study to evaluate the applicability of a simple and computationally attractive membrane system. Fluctuations in LeuT extracted from simulations are in good agreement with crystal logrophic B factors. Furthermore, key interactions identified in the X....... Specific interactions responsible for ligand recognition, are identified in the hSERT-5HT and hSERT-escitaloprom complexes. Our finding5 are in good agreement with predictions from mutagenesis studies....

  4. Molecular methods to evaluate effects of feed additives and nutrients in poultry gut microflora Metodologias moleculares para avaliar efeitos de aditivos e nutrientes na microflora intestinal das aves

    Directory of Open Access Journals (Sweden)

    Edgar O. Oviedo-Rondón

    2009-07-01

    Full Text Available Intestines of each animal are the niche of a complex and dynamic ecosystem with important effects to the host. The members or final products of this ecosystem influence nutrient digestion, absorption, mucosa metabolism, general physiology, and local and systemic immunological responses of avian hosts. Better understanding of the avian gut microbial ecosystem may lead to improvements on poultry productivity, health, welfare, and reduction of food borne pathogens and the environmental impact of poultry production for a more sustainable industry. Molecular methods of microbial ecology are key tools to gain this knowledge. The objective of this presentation is to outline the basic concepts, applications, advantages, limitations, and evolution of these molecular methods used to study intestinal microbial ecology. The final goal is to stimulate their application in poultry applied research and development of new feed additives. Some practical examples in poultry research will be described to illustrate their relevance to advance in control methods for pathogens, avoid or manage disbiosis or subclinical intestinal diseases, reduce environmental impact, elucidate effects of nutrients in gut mucosa, microflora, and in general to improve poultry performance.O intestino de cada animal é o nicho de um ecossistema complexo e dinâmico com efeitos importantes para o hospedeiro. As comunidades microbianas componentes deste ecossistema e/ou os produtos finais do metabolismo influenciam a digestão e absorção de nutrientes, o metabolismo das mucosas, a fisiologia geral e as respostas imunitárias locais e gerais da ave hospedeira. A melhor compreensão do ecossistema microbiano do intestino das aves pode levar a melhorias na produtividade, saúde, bem estar, e redução de agente patogênicos dos alimentos e do impacto ambiental da produção avícola para uma indústria mais sustentável. Os métodos moleculares da ecologia microbiana são ferramentas chaves

  5. Molecular dynamics study of interfacial confinement effects of aqueous NaCl brines in nanoporous carbon

    Energy Technology Data Exchange (ETDEWEB)

    Wander, M. C. F.; Shuford, K. L.

    2010-12-09

    In this paper, studies of aqueous electrolyte solutions in contact with a family of porous carbon geometries using classical molecular dynamics simulations are presented. These simulations provide an atomic scale depiction of ion transport dynamics in different environments to elucidate power of aqueous electrolyte supercapacitors. The electrolyte contains alkali metal and halide ions, which allow for the examination of size trends within specific geometries as well as trends in concentration. The electrode pores are modeled as planar graphite sheets and carbon nanotubes with interstices ranging from one to four nanometers. Ordered layers form parallel to the carbon surface, which facilitates focused ion motion under slightly confining conditions. As a result, the ion’s diffusivities are enhanced in the direction of the slit or pore. Further confining the system leads to decreased ion diffusivities. The ions are fully hydrated in all but the smallest slits and pores with those sizes showing increased ion pairing. There is strong evidence of charge separation perpendicular to the surface at all size scales, concentrations, and ion types, providing a useful baseline for examining differential capacitance behavior and future studies on energy storage. These systems show promise as high-power electrical energy storage devices.

  6. Exendin-4 na prevenção de danos teciduais decorrentes da morte encefálica e no controle bioenergético da célula β pancreática

    OpenAIRE

    Rodrigo Maron Carlessi

    2015-01-01

    A reposição de ilhotas pancreáticas é uma forma eficaz de se restabelecer a homeostase glicêmica em pacientes com diabetes mellitus tipo 1 com controle metabólico instável (“DM1 lábil”). Entretanto, ao longo do processo de isolamento, a partir do pâncreas do doador em morte encefálica (ME) e posterior enxerto no receptor, perdas importantes, tanto no número quanto na qualidade das ilhotas, limitam a eficácia do procedimento de transplante. Frequentemente, transplantes sequenciais de dois ou a...

  7. A molecular switch between the outer and the inner vestibule of the voltage-gated Na+ channel

    International Nuclear Information System (INIS)

    Zarrabi, T.

    2010-01-01

    conformational change of the inner vestibule generates the IUS state. In order to explain the involvement of both the outer and the inner vestibule in ultra-slow inactivation, we proposed a model in which the mutation K1237E produces a conformational change of the outer vestibule which is transmitted to the internal vestibule through the DIV- S6 segment. The resulting conformational change of the internal vestibule gives rise to the extremely stable IUS state. If this molecular mechanism holds true, then mutations at the location of interaction between the selectivity filter and the adjacent S6 segment should substantially modulate the ultra-slow inactivated state. A homology model of the voltage-gated Na+ channel, based on the crystal structure of the KcsA channel places the domain IV-S6 segment in close proximity to the domain III P-loop (containing the site 1237 which is essential for the generation of IUS). In order to search for experimental evidence for an interaction site between the domain III P-loop and the internal vestibule we generated serial alanine and cysteine replacements of amino acids of the domain DIV- S6 segment in the background of the mutation K1237E. We find that mutations only at the site 1575 substantially decrease the likelihood of entry into IUS or significantly accelerate recovery from IUS, suggesting that this residue represents an interaction site between the domain III p-loop and the domain IV- S6 segment. For the first time these functional data confirm a molecular model in which the turn of the domain III P-loop is in close relationship with the domain IV- S6 segment at the level of I1575. (author) [de

  8. Molecular simulation of thermodynamic and transport properties for the H{sub 2}O+NaCl system

    Energy Technology Data Exchange (ETDEWEB)

    Orozco, Gustavo A.; Jiang, Hao; Panagiotopoulos, Athanassios Z., E-mail: azp@princeton.edu [Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544 (United States); Moultos, Othonas A.; Economou, Ioannis G. [Chemical Engineering Program, Texas A and M University at Qatar, P.O. Box 23874, Doha (Qatar)

    2014-12-21

    Molecular dynamics and Monte Carlo simulations have been carried out to obtain thermodynamic and transport properties of the binary mixture H{sub 2}O+NaCl at temperatures from T = 298 to 473 K. In particular, vapor pressures, liquid densities, viscosities, and vapor-liquid interfacial tensions have been obtained as functions of pressure and salt concentration. Several previously proposed fixed-point-charge models that include either Lennard-Jones (LJ) 12-6 or exponential-6 (Exp6) functional forms to describe non-Coulombic interactions were studied. In particular, for water we used the SPC and SPC/E (LJ) models in their rigid forms, a semiflexible version of the SPC/E (LJ) model, and the Errington-Panagiotopoulos Exp6 model; for NaCl, we used the Smith-Dang and Joung-Cheatham (LJ) parameterizations as well as the Tosi-Fumi (Exp6) model. While none of the model combinations are able to reproduce simultaneously all target properties, vapor pressures are well represented using the SPC plus Joung-Cheathem model combination, and all LJ models do well for the liquid density, with the semiflexible SPC/E plus Joung-Cheatham combination being the most accurate. For viscosities, the combination of rigid SPC/E plus Smith-Dang is the best alternative. For interfacial tensions, the combination of the semiflexible SPC/E plus Smith-Dang or Joung-Cheatham gives the best results. Inclusion of water flexibility improves the mixture densities and interfacial tensions, at the cost of larger deviations for the vapor pressures and viscosities. The Exp6 water plus Tosi-Fumi salt model combination was found to perform poorly for most of the properties of interest, in particular being unable to describe the experimental trend for the vapor pressure as a function of salt concentration.

  9. Selectivity analyses of γ-benzylidene digoxin derivatives to different Na,K-ATPase α isoforms: a molecular docking approach.

    Science.gov (United States)

    Pessôa, Marco T C; Alves, Silmara L G; Taranto, Alex G; Villar, José A F P; Blanco, Gustavo; Barbosa, Leandro A

    2018-12-01

    Digoxin and other cardiotonic steroids (CTS) exert their effect by inhibiting Na,K-ATPase (NKA) activity. CTS bind to the various NKA isoforms that are expressed in different cell types, which gives CTS their narrow therapeutic index. We have synthesised a series of digoxin derivatives (γ-Benzylidene digoxin derivatives) with substitutions in the lactone ring (including non-oxygen and ether groups), to obtain CTS with better NKA isoform specificity. Some of these derivatives show some NKA isoform selective effects, with BD-3, BD-8, and BD-13 increasing NKA α2 activity, BD-5 inhibiting NKA α1 and NKA α3, BD-10 reducing NKA α1, but stimulating NKA α2 and α3; and BD-14, BD-15, and BD-16 enhancing NKA α3 activity. A molecular-docking approach favoured NKA isoform specific interactions for the compounds that supported their observed activity. These results show that BD compounds are a new type of CTS with the capacity to target NKA activity in an isoform-specific manner.

  10. Molecular dynamics study of structure and vibrational spectra at zwitterionoic lipid/aqueous KCl, NaCl, and CaCl2 solution interfaces

    Science.gov (United States)

    Ishiyama, Tatsuya; Shirai, Shinnosuke; Okumura, Tomoaki; Morita, Akihiro

    2018-06-01

    Molecular dynamics (MD) simulations of KCl, NaCl, and CaCl2 solution/dipalmytoylphosphatidylcholine lipid interfaces were performed to analyze heterodyne-detected vibrational sum frequency generation (HD-VSFG) spectra in relation to the interfacial water structure. The present MD simulation well reproduces the experimental spectra and elucidates a specific cation effect on the interfacial structure. The K+, Na+, and Ca2+ cation species penetrate in the lipid layer more than the anions in this order, due to the electrostatic interaction with negative polar groups of lipid, and the electric double layer between the cations and anions cancels the intrinsic orientation of water at the water/lipid interface. These mechanisms explain the HD-VSFG spectrum of the water/lipid interface and its spectral perturbation by adding the ions. The lipid monolayer reverses the order of surface preference of the cations at the solution/lipid interface from that at the solution/air interface.

  11. Molecular beam study of the a 3Σ+ state of NaK up to the dissociation limit

    Science.gov (United States)

    Temelkov, I.; Knöckel, H.; Pashov, A.; Tiemann, E.

    2015-03-01

    We provide spectroscopic data for the a 3Σ+ state of the 23Na39K molecule. The experiment is done in an ultrasonic beam apparatus, starting from the ground state X 1Σ+and driving the population to the a 3Σ+ state, using a Λ scheme with fixed pump and scanning dump laser. The signals are observed as dips of the total fluorescence. The intermediate level is chosen to be strongly perturbed by the B 1Π/c 3Σ+ states mixing to overcome the singlet-triplet transfer prohibition. We observed highly resolved hyperfine spectra of various rovibrational levels of the a 3Σ+state from va=2 up to the highest vibrational levels for rotational quantum numbers Na=4 ,6 ,8 . By the typical experimental linewidth of 17 MHz, the vibrational dependence of the hyperfine splitting is clearly revealed for NaK. The absolute frequency measurements of the vibrational levels are used for improvement of the a 3Σ+ potential curve and of the derived scattering length of all natural isotope combinations. Applying the Λ scheme in the reverse direction can provide a pathway for efficient transfer of ultracold 23Na39K molecules from the Na(3 s )+K(4 s ) asymptote to the lowest levels of the ground state. We show spectra that couple the absolute ground state vX=0 ,J =0 with an appropriate intermediate state for direct realization of the reverse path. The refined theoretical model of the coupled excited states of the Na(3 s )+K(4 p ) asymptote allows predictions of efficient paths for 23Na40K ; one example is calculated.

  12. Aplicaciones de la biología molecular en el aparato locomotor (proteína morfogenética ósea)

    OpenAIRE

    Carrillo Mateos, Juan Pablo; Carrillo Rivas, Belén

    2000-01-01

    La biología molecular constituye actualmente la base de la investigación biomédica. Gracias a la moderna técnica de transcripción inversa es posible obtener in Vitro proteínas humanas en gran cantidad. Un ejemplo de ello es la proteína morfogenética ósea recombinante humana (rhBMP), utilizada hasta ahora en forma experimental debido la disparidad de resultados observados en animales de experimentación y en humanos. Existen aún preguntas importantes que se deben responder antes de poder usar e...

  13. Na+/K+-ATPase α-subunit in swimming crab Portunus trituberculatus: molecular cloning, characterization, and expression under low salinity stress

    Science.gov (United States)

    Han, Xiaolin; Liu, Ping; Gao, Baoquan; Wang, Haofeng; Duan, Yafei; Xu, Wenfei; Chen, Ping

    2015-07-01

    Na+/K+-ATPases are membrane-associated enzymes responsible for the active transport of Na+ and K+ ions across cell membranes, generating chemical and electrical gradients. These enzymes' α-subunit provides catalytic function, binding and hydrolyzing ATP, and itself becoming phosphorylated during the transport cycle. In this study, Na+/K+-ATPase α-subunit cDNA was cloned from gill tissue of the swimming crab Portunus trituberculatus by reverse-transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA end methods. Analysis of the nucleotide sequence revealed that the cDNA had a full-length of 3 833 base pairs (bp), with an open reading frame of 3 120 bp, 5' untranslated region (UTR) of 317 bp, and 3' UTR of 396 bp. The sequence encoded a 1 039 amino acid protein with a predicted molecular weight of 115.57 kDa and with estimated pI of 5.21. It was predicted here to possess all expected features of Na+/K+-ATPase members, including eight transmembrane domains, putative ATP-binding site, and phosphorylation site. Comparison of amino acid sequences showed that the P. trituberculatus α-subunit possessed an overall identity of 75%-99% to that of other organisms. Phylogenetic analysis revealed that this α-subunit was in the same category as those of crustaceans. Quantitative real-time RT-PCR analysis indicated that this α-subunit's transcript were most highly expressed in gill and lowest in muscle. RT-PCR analysis also revealed that α-subunit expression in crab gill decreased after 2 and 6 h, but increased after 12, 24, 48, and 72 h. In addition, α-subunit expression in hepatopancreas of crab decreased after 2-72 h. These facts indicated that the crab's Na+/K+-ATPase α-subunit was potentially involved in the observed acute response to low salinity stress.

  14. Synthesis of cerium oxide catalysts supported on MCM-41 molecular sieve; Sintese de catalisadores de oxido de cerio suportados na peneira molecular MCM-41

    Energy Technology Data Exchange (ETDEWEB)

    Souza, E.L.S.; Barros, T.R.B.; Sousa, B.V. de, E-mail: emylle.souza@gmail.com [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia Quimica

    2016-07-01

    Porous materials have been widely studied as catalysts and catalyst support. The MCM-41 structure is the one that has been most studied because of its application possibilities in chemical processes. This work aimed to obtain and characterize cerium oxide catalysts supported on MCM-41 molecular sieve. The molecular sieve was synthesized by the conventional method with the following molar composition: 1 SiO2: 0.30 CTABr: NH3 11: 144 H2O. Then, 25% w/w cerium was incorporated into the MCM-41 using the wet impregnation process and the material obtained was activated by calcination. From the XRD patterns was confirmed the structure of the molecular sieve, and were identified the cerium oxide phases in its structure. The textural catalysts characteristics were investigated by isotherms of N2 adsorption/desorption (BET method). (author)

  15. Rapid Formation of Molecular Bromine from Deliquesced NaBr Aerosol in the Presence of Ozone and UV Light

    Science.gov (United States)

    The formation of gas-phase bromine from aqueous sodium bromide aerosols is investigated through a combination of chamber experiments and chemical kinetics modeling. Experiments show that Br2(g) is produced rapidly from deliquesced NaBr aerosols in the presence of OH radicals prod...

  16. Ion pump as molecular ratchet and effects of noise: electric activation of cation pumping by Na,K-ATPase

    Science.gov (United States)

    Tsong, T. Y.; Xie, T. D.

    2002-08-01

    Na,K-ATPase is a universal ion pump of the biological cell. Under physiological conditions, it uses the γ-phosphorus bond energy of ATP during hydrolysis to pump 2 K+ inward and 3 Na+ outward; both being uphill transports. The experiment presented here demonstrates that the protein transporter can also use electric energy to fuel its pump activity. A theory of electroconformational coupling (TEC) is described and an experiment performed to verify several predictions of the model. Analysis based on the TEC model suggests that Na,K-ATPase is a Brownian ratchet. The enzyme harvests energy from the applied field by means of the field-induced conformational oscillation or fluctuation. However, high efficiency of energy transduction can only be achieved with an electric field of certain intensities, frequencies and waveforms. This property of the enzyme allows us to define an electric signal and differentiate it from electric noise on the basis of the analysis by the TEC model. Data show that electric noise alone does not induce pump activity. However, an appropriate power level of noise imposed on a signal can enhance the pump efficiency. The effect of noise on the signal transduction of Na,K-ATPase is reminiscent of the stochastic resonance phenomenon reported in other biological systems [3, 35]. The TEC model embodies many common features of enzymes and biological motors. It is potentially energy-efficient, much more so than models based on the ion-rectification mechanism.

  17. Marcadores moleculares derivados de sequências expressas do genoma café potencialmente envolvidas na resistência à ferrugem

    Directory of Open Access Journals (Sweden)

    Samuel Mazzinghy Alvarenga

    2011-08-01

    Full Text Available O objetivo deste trabalho foi identificar marcadores moleculares relacionados à resistência do cafeeiro (Coffea arabica à ferrugem (Hemileia vastatrix. Foram identificadas sequências de DNA potencialmente envolvidas na resistência do cafeeiro a doenças, por meio de análise "in silico", a partir das informações geradas pelo Projeto Brasileiro do Genoma Café. A partir das sequências mineradas, foram desenhados 59 pares de iniciadores para amplificá-las. Os 59 iniciadores foram testados em 12 cafeeiros resistentes e 12 susceptíveis a H. vastatrix. Vinte e sete iniciadores resultaram em bandas únicas e bem definidas, enquanto um deles amplificou fragmento de DNA em todos os cafeeiros resistentes, mas não nos suscetíveis. Esse marcador molecular polimórfico amplificou uma região do DNA que corresponde a uma janela aberta de leitura parcial do genoma de C. arabica que codifica uma proteína de resistência a doenças. O marcador CARF 005 é capaz de diferenciar os cafeeiros analisados em resistentes e susceptíveis a H. vastatrix.

  18. Influence of incorporation method of sulfated zirconia in MCM-41 molecular sieve; Influencia do metodo de incorporacao da zirconia sulfatada na peneira molecular MCM-41

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, C.E.; Santos, J.S.B.; Cavalcante, J.N.A.; Andrade, M.R.A.; Sousa, B.V., E-mail: eduardopereira.eq@gmail.com [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Centro de Ciencia e Tecnologia

    2016-07-01

    Sulfated metal oxides and sulfated zirconia have attracted great attention in recent years due to its high catalytic activity. The sulfated zirconia has the function of assigning the acidic material, through the formation of Bronsted acids and Lewis sites. The incorporation of sulfated zirconia in MCM-41 molecular sieve was carried out through the techniques: dry and wet. The wet process involves the use of an excess of solution on the volume of the support pores. Therefore, the concentration of the metal precursor on the support depends on the solution concentration and the pore volume of the support. In the process of incorporating by dry, the volume of the solution containing the precursor does not exceed the pore volume of the support. After either procedure, the impregnated support must be dried in order to allow the precursor compound can be converted into a catalytically active phase. This study aims to evaluate two methods of incorporation of sulfated zirconia in the mesoporous molecular sieve MCM-41. The process of merger took for wet and dry impregnation. Through the XRD patterns it was possible to identify the presence of the hexagonal structure of the molecular sieve, as well as the tetragonal and monoclinic phases of zirconia. From the spectroscopic analysis in the infrared region to the method the wet, it was possible to identify the vibrational frequencies related to the merger of sulfated zirconia in the MCM-41 structure of the molecular sieve. (author)

  19. Development of a pilot molecular distillation unit; Desenvolvimento de unidade de destilacao molecular nacional e aplicacao na avaliacao de petroleos extrapesados

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Erica Roberta Lovo da; Maciel, Maria Regina Wolf; Maciel Filho, Rubens; Batistella, Cesar Benedito [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Medina, Lilian Carmem [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    Due to the importance and the need in studies with heavy and extra heavy petroleums and their residues, it was designed and built up by the oil research group of LOPCA/LDPS/FEQ/UNICAMP, in partnership with the Laboratory of Valuation Processes of CENPES / PETROBRAS, a pilot plant of falling film molecular distiller (national prototype), where some specific operational facilities were introduced. This project resulted in a suitable system for distillation of products of high molecular weight and thermally sensitive, without degradation of them. This work aims the achievement of distillate fractions of atmospheric residue 400 deg C+, using the new molecular distillation equipment. The experiments were carried out according to factorial design to assess the significant process variables in the molecular distillation prototype. The results showed that the evaporator temperature has high influence on the process and the feed flow rate has minimum influence, as it is desired. Additionally, the equipment showed easy handing operation, high operational stability and results varying around 1%. (author)

  20. A construção social de gênero na Biologia: preconceitos e obstáculos na biologia molecular Social construction of gender in biology: prejudice and barriers in molecular biology

    Directory of Open Access Journals (Sweden)

    Neide Mayumi Osada

    2006-12-01

    Full Text Available Este paper tem como objetivo analisar a presença de homens e mulheres nas ciências biológicas a partir do Projeto Genoma Fapesp (PGF. Baseado nos estudos sociais das ciências e nos estudos de gênero em ciências, pretende-se, portanto, entender as principais razões que levam ao avanço mais lento na carreira das mulheres pesquisadoras, analisar como ocorre a participação das mulheres na construção das ciências e, por fim, avaliar os principais obstáculos por elas enfrentados.This paper analyses the presence of women and men in Biological Sciences, specifically at the Fapesp Genome Project. Considering the Social Studies of Sciences and Gender Studies, this article highlights the barrier and prejudices women face in their scientific carrier and show how this reproduces a situation in which men advance faster than women.

  1. Formation of molecular bromine from the reaction of ozone with deliquesced NaBr aerosol: Evidence for interface chemistry

    Czech Academy of Sciences Publication Activity Database

    Hunt, S. W.; Roeselová, Martina; Wang, W.; Wingen, L. M.; Knipping, E. M.; Tobias, D. J.; Dabdub, D.; Finlayson-Pitts, B. J.

    2004-01-01

    Roč. 108, - (2004), s. 11559-11572 ISSN 1089-5639 Grant - others:NSF(US) 0209719; NSF(US) 0431512 Institutional research plan: CEZ:AV0Z4055905 Keywords : ozone * sea-salt aerosol * molecular dynamics simulation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.639, year: 2004

  2. Osmotic Pressure of Aqueous Electrolyte Solutions via Molecular Simulations of Chemical Potentials: Application to NaCl.

    Czech Academy of Sciences Publication Activity Database

    Smith, W.R.; Moučka, F.; Nezbeda, Ivo

    2016-01-01

    Roč. 407, Sl (2016), s. 76-83 ISSN 0378-3812 Grant - others:NSERC(CA) OGP1041 Institutional support: RVO:67985858 Keywords : osmotic pressure * chemical potential * molecular simulation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.473, year: 2016

  3. Molecular imaging of enhanced Na + expression in the liver of total sleep deprived rats by TOF-SIMS

    Science.gov (United States)

    Chang, Hung-Ming; Chen, Bo-Jung; Wu, Un-In; Huang, Yi-Lun; Mai, Fu-Der

    2008-12-01

    Sleep disorder is associated with metabolic disturbances, which was related to oxidative stress and subsequently sodium overload. Since liver plays important roles in metabolic regulation, present study is aimed to determine whether hepatic sodium, together with oxidative stress, would significantly alter after total sleep deprivation (TSD). Sodium ion was investigated by time-of-flight secondary ion mass spectrometry (TOF-SIMS). Parameter for oxidative stress was examined by heat shock protein-25 (HSP-25) immunohistochemistry. TOF-SIMS spectrum indicated that hepatic Na +/K + ratio counting as 82.41 ± 9.5 was obtained in normal rats. Sodium ions were distributed in hepatocytes with several aggregations. However, following TSD, the intensity for Na +/K + ratio was relatively increased (101.94 ± 6.9) and signals for sodium image were strongly expressed throughout hepatocytes without spatial localization. Quantitative analysis revealed that HSP-25 staining intensity is 1.78 ± 0.27 in TSD rats, which was significantly higher than that of normal ones (0.68 ± 0.15). HSP-25 augmentation suggests that hepatocytes suffer from oxidative stress following TSD. Concerning oxidative stress induced sodium overload would impair metabolic function; enhanced hepatic sodium expression after TSD may be a major cause of TSD relevant metabolic diseases.

  4. Alteration in DNA structure, molecular responses and Na+ -K+ -ATPase activities in the gill of Nile tilapia, Oreochromis niloticus (Linnaeus, 1758) in response to sub-lethal verapamil.

    Science.gov (United States)

    Ajima, Malachy N O; Pandey, Pramod K; Kumar, Kundan; Poojary, Nalini

    2018-01-01

    The ecotoxicological consequences of residues from pharmaceutical drugs on aquatic biota have necessitated the development of sensitive and reliable techniques to assess the impact of these xenobiotics on aquatic organisms. This study investigated the alteration in DNA structure, molecular responses and the activities of Na + -K + -ATPase and antioxidant enzymes in the gill of Nile tilapia, Oreochromis niloticus, exposed to long-term effects at the concentrations (0.14, 0.28 and 0.57mgL -1 ) of verapamil in static renewal system for 15, 30, 45 and 60 days. Evaluation of DNA structure, using single cell gel electrophoresis, revealed certain degree of DNA damages in the gill in a time and concentration-dependent relationship. Transcription of mRNA of superoxide dismutase (sod), catalase (cat) and heat shock protein (hsp70) genes in the gill of the fish showed the genes were up-regulated. Na + -K + -ATPase activity was inhibited in a concentration and time dependent manner. The indices of oxidative stress biomarkers (lipid peroxidation and carbonyl protein) as well as superoxide dismutase, glutathione peroxidase, glutathione-S-transferase were elevated in the treated fish in comparison to the control. Further, the level of reduced glutathione and catalase activity were inhibited at 0.28mgL -1 after day 30. Long-term exposure to sub-lethal concentration of verapamil can cause DNA damages, molecular effects and oxidative stress in O. niloticus. The biomarkers analysed can be used as early warning signals in environmental biomonitoring and assessment of drug contamination in aquatic ecosystem. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Interplay between structure and transport properties of molten salt mixtures of ZnCl2-NaCl-KCl: A molecular dynamics study.

    Science.gov (United States)

    Manga, Venkateswara Rao; Swinteck, Nichlas; Bringuier, Stefan; Lucas, Pierre; Deymier, Pierre; Muralidharan, Krishna

    2016-03-07

    Molten mixtures of network-forming covalently bonded ZnCl2 and network-modifying ionically bonded NaCl and KCl salts are investigated as high-temperature heat transfer fluids for concentrating solar power plants. Specifically, using molecular dynamics simulations, the interplay between the extent of the network structure, composition, and the transport properties (viscosity, thermal conductivity, and diffusion) of ZnCl2-NaCl-KCl molten salts is characterized. The Stokes-Einstein/Eyring relationship is found to break down in these network-forming liquids at high concentrations of ZnCl2 (>63 mol. %), while the Eyring relationship is seen with increasing KCl concentration. Further, the network modification due to the addition of K ions leads to formation of non-bridging terminal Cl ions, which in turn lead to a positive temperature dependence of thermal conductivity in these melts. This new understanding of transport in these ternary liquids enables the identification of appropriate concentrations of the network formers and network modifiers to design heat transfer fluids with desired transport properties for concentrating solar power plants.

  6. EPIDEMIOLOGIA MOLECULAR APLICADA AO MONITORAMENTO DE ESTIRPES DE Staphylococcus aureus NA PRODUÇÃO DE QUEIJO MINAS FRESCAL

    Directory of Open Access Journals (Sweden)

    Maria Izabel Merino de Medeiros

    2013-03-01

    Full Text Available We studied the molecular epidemiology of Staphylococcus aureus strains potentially toxigenic, isolated from the production process of Minas frescal cheese in a small dairy plant in the state of São Paulo. For this, samples were taken during the period from June 2008 to July 2009. Samples were collected from the surface of the receiving and storage tanks of raw milk, the surface of the balance tank of pasteurized milk, the water supply system, the pipes and equipments, the hands of the handler and from the packaged cheese, totaling 140 samples. The colonies isolated on Baird-Parker Agar confirmed as Gram positive and positive for catalase, coagulase and acetoin production, were submitted to extraction of bacterial DNA using the Invitek - Uniscience® kit. Confirmation of the isolated species and enterotoxins SEA, SEB, SEC, SED and TSST-1 toxin was carried out through the amplification of specific fragments of chromosomal DNA. Among the 74 strains of isolated coagulase-positive staphylococci, only 41 (55.4% strains were confirmed as Staphylococcus aureus, of which 25 (61.0% were positive to the presence of staphylococcal toxins. The most frequently identified enterotoxin was SEA. The toxigenic strains of Staphylococcus aureus were more frequently isolated from hands of the handler (16.0%, raw milk receiving tank (12.0%, pasteurized milk for cheese making (12.0% and fresh white cheese ready for consumption (12.0%.

  7. Molecular and functional characterization of seven Na+/K+-ATPase β subunit paralogs in Senegalese sole (Solea senegalensis Kaup, 1858).

    Science.gov (United States)

    Armesto, Paula; Infante, Carlos; Cousin, Xavier; Ponce, Marian; Manchado, Manuel

    2015-04-01

    In the present work, seven genes encoding Na(+),K(+)-ATPase (NKA) β-subunits in the teleost Solea senegalensis are described for the first time. Sequence analysis of the predicted polypeptides revealed a high degree of conservation with those of other vertebrate species and maintenance of important motifs involved in structure and function. Phylogenetic analysis clustered the seven genes into four main clades: β1 (atp1b1a and atp1b1b), β2 (atp1b2a and atp1b2b), β3 (atp1b3a and atp1b3b) and β4 (atp1b4). In juveniles, all paralogous transcripts were detected in the nine tissues examined albeit with different expression patterns. The most ubiquitous expressed gene was atp1b1a whereas atp1b1b was mainly detected in osmoregulatory organs (gill, kidney and intestine), and atp1b2a, atp1b2b, atp1b3a, atp1b3b and atp1b4 in brain. An expression analysis in three brain regions and pituitary revealed that β1-type transcripts were more abundant in pituitary than the other β paralogs with slight differences between brain regions. Quantification of mRNA abundance in gills after a salinity challenge showed an activation of atp1b1a and atp1b1b at high salinity water (60 ppt) and atp1b3a and atp1b3b in response to low salinity (5 ppt). Transcriptional analysis during larval development showed specific expression patterns for each paralog. Moreover, no differences in the expression profiles between larvae cultivated at 10 and 35 ppt were observed except for atp1b4 with higher mRNA levels at 10 than 35 ppt at 18 days post hatch. Whole-mount in situ hybridization analysis revealed that atp1b1b was mainly localized in gut, pronephric tubule, gill, otic vesicle, and chordacentrum of newly hatched larvae. All these data suggest distinct roles of NKA β subunits in tissues, during development and osmoregulation with β1 subunits involved in the adaptation to hyperosmotic conditions and β3 subunits to hypoosmotic environments. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Common molecular determinants of tarantula huwentoxin-IV inhibition of Na+ channel voltage sensors in domains II and IV.

    Science.gov (United States)

    Xiao, Yucheng; Jackson, James O; Liang, Songping; Cummins, Theodore R

    2011-08-05

    The voltage sensors of domains II and IV of sodium channels are important determinants of activation and inactivation, respectively. Animal toxins that alter electrophysiological excitability of muscles and neurons often modify sodium channel activation by selectively interacting with domain II and inactivation by selectively interacting with domain IV. This suggests that there may be substantial differences between the toxin-binding sites in these two important domains. Here we explore the ability of the tarantula huwentoxin-IV (HWTX-IV) to inhibit the activity of the domain II and IV voltage sensors. HWTX-IV is specific for domain II, and we identify five residues in the S1-S2 (Glu-753) and S3-S4 (Glu-811, Leu-814, Asp-816, and Glu-818) regions of domain II that are crucial for inhibition of activation by HWTX-IV. These data indicate that a single residue in the S3-S4 linker (Glu-818 in hNav1.7) is crucial for allowing HWTX-IV to interact with the other key residues and trap the voltage sensor in the closed configuration. Mutagenesis analysis indicates that the five corresponding residues in domain IV are all critical for endowing HWTX-IV with the ability to inhibit fast inactivation. Our data suggest that the toxin-binding motif in domain II is conserved in domain IV. Increasing our understanding of the molecular determinants of toxin interactions with voltage-gated sodium channels may permit development of enhanced isoform-specific voltage-gating modifiers.

  9. Purification, characterization, molecular cloning and extracellular production of a phospholipase A1 from Streptomyces albidoflavus NA297.

    Science.gov (United States)

    Sugimori, Daisuke; Kano, Kota; Matsumoto, Yusaku

    2012-01-01

    A novel metal ion-independent phospholipase A1 of Streptomyces albidoflavus isolated from Japanese soil has been purified and characterized. The enzyme consists of a 33-residue N-terminal signal secretion sequence and a 269-residue mature protein with a deduced molecular weight of 27,199. Efficient and extracellular production of the recombinant enzyme was successfully achieved using Streptomyces lividans cells and an expression vector. A large amount (25 mg protein, 14.7 kU) of recombinant enzyme with high specific activity (588 U/mg protein) was purified by simple purification steps. The maximum activity was found at pH 7.2 and 50 °C. At pH 7.2, the enzyme preferably hydrolyzed phosphatidic acid and phosphatidylserine; however, the substrate specificity was dependent on the reaction pH. The enzyme hydrolyzed lysophosphatidylcholine and not triglyceride and the p-nitrophenyl ester of fatty acids. At the reaction equilibrium, the molar ratio of released free fatty acids (sn-1:sn-2) was 63:37. The hydrolysis of phosphatidic acid at 50 °C and pH 7.2 gave apparent V max and k cat values of 1389 μmol min(-1) mg protein(-1) and 630 s(-1), respectively. The apparent K m and k cat/K m values were 2.38 mM and 265 mM(-1) s(-1), respectively. Mutagenesis analysis showed that Ser11 is essential for the catalytic function of the enzyme and the active site may include residues Ser216 and His218.

  10. The effect of prophylactic dose of a low molecular weight heparin on skin wound healing of rats Efeito da dose profilática de heparina de baixo peso molecular na cicatrização de feridas na pele de ratos

    Directory of Open Access Journals (Sweden)

    Ozdamar Fuad Oken

    2009-12-01

    Full Text Available PURPOSE: To investigate the effect of prophylactic dose of a low molecular weight heparin, enoxaparin, on skin wound healing of rats. METHODS: Forty rats were used for the study. Rats were randomly assigned to two equal groups. Experimental group received prophylactic dose of enoxaparin. Physiologic saline was administered to the control group. Parameters of wound healing of experimental and control groups were compared. For comparison of the groups in terms of fibrosis, vascularization, inflammation, epithelization, and tensile strength test (Newton. Mann-Whitney-U test was used because variables were categorical data (fibrosis, vascularization, inflammation and epithelization. Differences between groups were analyzed with independent samples t-test (tensile strength. Significance was set at pOBJETIVO: Investigar o efeito de dose profilática da heparina de baixo peso molecular, enoxaparina, na cicatrização de feridas na pele de ratos. MÉTODOS: Quarenta ratos foram utilizados para o estudo. Ratos foram distribuídos aleatoriamente a dois grupos iguais. O grupo experimental recebeu profilática de enoxaparina. Solução salina fisiologica foi administrada ao grupo controle. Foram comparados parâmetros de cicatrização dos grupos experimental e controle.Os grupos foram comparados em termos de fibrose, vascularização, inflamação, epitelização e força tensil (teste de Newton. Foi realizado o teste de Mann-Whitney-U para variáveis com dados categóricos (fibrose, cicatrização, inflamação e epitelização. Diferenças entre os grupos foram analisadas como amostras independentes pelo t-teste (força tensil. Significância foi fixada para p < 0,05. RESULTADOS: A ferida do grupo experimental apresentou força tensil diminuída significativamente (p < 0,001, o exame histopatológico revelou um significativo (p < 0,001 retardo na epitelização e diminuição na fibrose, cicatrização, inflamação (p < 0,001 no grupo experimental

  11. Molecular dynamics simulations of the electrical double layer on smectite surfaces contacting concentrated mixed electrolyte (NaCl-CaCl2)

    Energy Technology Data Exchange (ETDEWEB)

    Bourg, I.C.; Sposito, G.

    2011-04-01

    We report new molecular dynamics results elucidating the structure of the electrical double layer (EDL) on smectite surfaces contacting mixed NaCl-CaCl{sup 2} electrolyte solutions in the range of concentrations relevant to pore waters in geologic repositories for CO{sub 2} or high-level radioactive waste (0.34-1.83 mol{sub c} dm{sup -3}). Our results confirm the existence of three distinct ion adsorption planes (0-, {beta}-, and d-planes), often assumed in EDL models, but with two important qualifications: (1) the location of the {beta}- and d-planes are independent of ionic strength or ion type and (2) 'indifferent electrolyte' ions can occupy all three planes. Charge inversion occurred in the diffuse ion swarm because of the affinity of the clay surface for CaCl{sup +} ion pairs. Therefore, at concentrations 0.34 mol{sub c} dm{sup -3}, properties arising from long-range electrostatics at interfaces (electrophoresis, electro-osmosis, co-ion exclusion, colloidal aggregation) will not be correctly predicted by most EDL models. Co-ion exclusion, typically neglected by surface speciation models, balanced a large part of the clay mineral structural charge in the more concentrated solutions. Water molecules and ions diffused relatively rapidly even in the first statistical water monolayer, contradicting reports of rigid 'ice-like' structures for water on clay mineral surfaces.

  12. Molecular dynamics simulations of the electrical double layer on smectite surfaces contacting concentrated mixed electrolyte (NaCl-CaCl2) solutions.

    Science.gov (United States)

    Bourg, Ian C; Sposito, Garrison

    2011-08-15

    We report new molecular dynamics results elucidating the structure of the electrical double layer (EDL) on smectite surfaces contacting mixed NaCl-CaCl(2) electrolyte solutions in the range of concentrations relevant to pore waters in geologic repositories for CO(2) or high-level radioactive waste (0.34-1.83 mol(c) dm(-3)). Our results confirm the existence of three distinct ion adsorption planes (0-, β-, and d-planes), often assumed in EDL models, but with two important qualifications: (1) the location of the β- and d-planes are independent of ionic strength or ion type and (2) "indifferent electrolyte" ions can occupy all three planes. Charge inversion occurred in the diffuse ion swarm because of the affinity of the clay surface for CaCl(+) ion pairs. Therefore, at concentrations ≥0.34 mol(c) dm(-3), properties arising from long-range electrostatics at interfaces (electrophoresis, electro-osmosis, co-ion exclusion, colloidal aggregation) will not be correctly predicted by most EDL models. Co-ion exclusion, typically neglected by surface speciation models, balanced a large part of the clay mineral structural charge in the more concentrated solutions. Water molecules and ions diffused relatively rapidly even in the first statistical water monolayer, contradicting reports of rigid "ice-like" structures for water on clay mineral surfaces. Published by Elsevier Inc.

  13. Structural study of Na2O-B2O3-SiO2 glasses from molecular simulations using a polarizable force field.

    Science.gov (United States)

    Pacaud, Fabien; Delaye, Jean-Marc; Charpentier, Thibault; Cormier, Laurent; Salanne, Mathieu

    2017-10-28

    Sodium borosilicate glasses Na 2 O-B 2 O 3 -SiO 2 (NBS) are complex systems from a structural point of view. Three main building units are present: tetrahedral SiO 4 and BO 4 (B IV ) and triangular BO 3 (B III ). One of the salient features of these compounds is the change of the B III /B IV ratio with the alkali concentration, which is very difficult to capture in force fields-based molecular dynamics simulations. In this work, we develop a polarizable force field that is able to reproduce the boron coordination and more generally the structure of several NBS systems in the glass and in the melt. The parameters of the potential are fitted from density functional theory calculations only, in contrast with the existing empirical potentials for NBS systems. This ensures a strong improvement on the transferability of the parameters from one composition to another. Using this new force field, the structure of NBS systems is validated against neutron diffraction and nuclear magnetic resonance experiments. A special focus is given to the distribution of B III /B IV with respect to the composition and the temperature.

  14. Mecanismos moleculares de ação anti-inflamatória e antioxidante de polifenóis de uvas e vinho tinto na aterosclerose

    Directory of Open Access Journals (Sweden)

    M. Séfora-Sousa

    2013-01-01

    Full Text Available Este trabalho visa investigar os possíveis mecanismos moleculares de ação dos polifenóis de uvas e vinho tinto contra os processos oxidativos e inflamatórios envolvidos na aterosclerose. Trata-se de um estudo de revisão de literatura realizado por meio de buscas nas bases de dados PubMed e ScienceDirect utilizando os seguintes descritores: vinho tinto, uva, polifenóis, resveratrol, aterosclerose, LDL-oxidada, inflamação, estresse oxidativo, NF-kB, AP-1, Nrf2, SIRT-1, MicroRNA. Embora tais mecanismos ainda não estejam totalmente esclarecidos, os estudos indicam que compostos fenólicos presentes em uvas podem se complexar com metais (como ferro e cobre que provocam peroxidação dos lipídios, aumentam a atividade antioxidante do plasma, associam-se com a LDL-c aumentando sua resistência à oxidação, preservam a atividade da enzima paraoxonase, neutralizam radicais livres, e ativam fatores de transcrição como o Nrf2, que aumenta a expressão de genes que codificam proteínas importantes na defesa antioxidante, como a superóxido dismutase e a glutationa peroxidase. Além disso, os polifenóis inibem a fosforilação de MAP quinases, inibindo assim os fatores de transcrição NF-kB e AP-1 e, consequentemente, reduzindo a síntese do TNF-á, interleucinas, moléculas de adesão e quimiocinas. Também inibem a atividade das enzimas cicloxigenase e lipoxigenase. Outro mecanismo proposto é a ação do resveratrol sobre a atividade de deacetilases de histonas, como a SITR-1. Estas ações em conjunto reduzem a oxidação da LDL-c e o processo inflamatório, atenuando o processo aterogênico.

  15. Comparación de metodologías moleculares para identificar el gen de la kappa caseína en ganado Holstein

    Directory of Open Access Journals (Sweden)

    Carlos Solarte P.

    2012-04-01

    Full Text Available Objetivo. Comparar las metodologías moleculares, PCR-RFLPs y PCR-SSCP, para identificar las variantes alélicas del gen de la kappa caseína (CSN3 en bovinos Holstein del trópico alto de Nariño-Colombia. Materiales y métodos. Se escogieron al azar 50 vacas Holstein y mediante punción en la vena coxígea media se tomaron muestras de 5cc de sangre, que se almacenaron y preservaron en tarjetas FTA® para su posterior análisis en el laboratorio. El ADN se amplificó por PCR utilizando cebadores específicos. Los cambios en la conformación de cadena sencilla (SSCP fueron visualizados en geles de poliacrilamida al 12%; mientras que los RFLPs se obtuvieron por digestión con tres enzimas de restricción y se visualizaron en geles de agarosa al 4%. Resultados. La metodología PCR-RFLPs fue útil para detectar mutaciones puntuales y por lo tanto se identificó un mayor número de alelos, lo que contribuye a una mejor estimación de las medidas de diversidad genética en poblaciones seleccionadas, ya que evita problemas de sobreestimación de los valores en las frecuencias alélicas. Por su parte, la técnica PCR-SSCP resultó más sencilla y económica, ideal para investigaciones en las que no existe información previa sobre los genotipos de las poblaciones bovinas y en estudios con bajos presupuestos. Conclusiones. Las dos metodologías evaluadas son herramientas moleculares que contribuyen a la orientación de los procesos de selección en los bovinos para leche, ya que identifican los alelos del gen CSN3. La diferencia radica en el costo de las mismas y en el número de variantes identificadas.

  16. Influência da temperatura na infecção de tilápias do Nilo por Streptococcus agalactiae

    Directory of Open Access Journals (Sweden)

    Paulo Fernandes Marcusso

    2015-04-01

    Full Text Available Mudanças ambientais afetam a homeostase dos peixes, tornando-os mais suscetíveis a doenças. No Brasil, tem sido relatados surtos de infecção por Streptococcus agalactiae em tilápia do Nilo, principalmente quando se encontram fora da zona de conforto térmico. No presente trabalho, foi avaliada a taxa de mortalidade e determinado quais foram os órgãos mais afetados por essa bactéria em temperaturas que ocorrem naturalmente no Sul do Brasil. Quarenta tilápias-do-nilo (Oreochromis niloticus foram infectadas por Streptococcus agalactiae e distribuídas em quatro grupos (n = 10, cada um deles submetidos a diferentes temperaturas: G1: 24°C, G2: 26°C, G3: 28°C e G4: 32°C. Os peixes foram monitorados durante 10 dias. Os peixes com sinais clínicos irreversíveis foram sacrificados e coletadas amostras de cérebro, fígado e rins para analise bacteriológica e molecular. Foram observados sinais compatíveis com infecção estreptocócica em todos os grupos. A taxa de mortalidade mais elevada ocorreu nos grupos mantidos nas temperaturas de 24°C e 32°C. O cérebro foi o órgão mais afetado, com a maior percentagem de isolamento de S. agalactiae pelos dois métodos de diagnostico. Os resultados sugerem que, tal como nos mamíferos, temperaturas que estão mais afastadas da zona de conforto afetam significativamente a homeostase dos peixes, aumentando a sua susceptibilidade para infecções bacterianas.

  17. Molecular basis for interaction of Na+/K+-ATPase with other transporters in membrane microdomains of vascular smooth muscle cells

    DEFF Research Database (Denmark)

    Hansen, Anne Kirstine; Matchkov, Vladimir; Bouzinova, Elena

    2008-01-01

    Ouabain, a specific inhibitor of the Na+/K+-pump, has previously been shown to interfere with intercellular communication. We have recently demonstrated a mechanism of this action of ouabain (1). We have showed that gap junctions between vascular smooth muscle cells (SMCs) are regulated through...... an interaction between the Na+/K+-pump and the Na+/Ca2+-exchanger leading to an increase in the intracellular calcium concentration in discrete areas near the plasma membrane. This regulation suggests a close association of the proteins in microdomains. We have also suggested that this Na...

  18. Separation of the genera in the subtribe Cassiinae (Leguminosae: Caesalpinioidae using molecular markers Separação dos gêneros na subtribo Cassiinae (Leguminosae: Caesalpinioidae utilizando marcadores moleculares

    Directory of Open Access Journals (Sweden)

    Laxmikanta Acharya

    2011-03-01

    Full Text Available Random amplified polymorphic DNA (RAPD, Inter simple sequence repeat (ISSR and Amplified fragment length polymorphism (AFLP markers were used to verify the segregation of the genus Cassia L. senso lato into three distinct genera namely Chamaecrista Moench., Senna P. Mill. and Cassia L. sensostricto Eighteen representatives of the three taxa were characterized using the molecular markers. 25 RAPD, six ISSR primers and six AFLP primer combinations resulted in the amplification of 612, 115 and 622 bands (loci respectively. Most of the loci are found to be polymorphic, showing high degrees of genetic diversity among the different taxa studied. The dendrogram constructed on the basis of the RAPD, ISSR and AFLP data using SHAN clustering, divided Cassia L. senso lato. into three different clusters as Chamaecrista Moench. Senna P. Mill. and Cassia L. senso stricto High bootstrap value revealed that all the clusters were stable and robust. It was observed from the present investigation that these genera have their identity at molecular level, which supports the elevation of the genus Cassia L. senso lato to the level of subtribe Cassiinae and segregation into three distinct genera instead of intrageneric categories.Técnicas de Random amplified polymorphic DNA (RAPD, Inter simple sequence repeat (ISSR e Amplified Fragment Length Polymorphism markers (AFLP foram utilizadas para verificar a segregação do gênero Cassia L. senso lato em três diferentes gêneros, Chamaecrista Moench., Senna P. Mill. e Cassia L. senso stricto Dezoito representantes dos três táxons foram caracterizados com o uso de marcadores moleculares: 25 RAPD, seis iniciadores ("primers" ISSR e seis AFLP combinações de iniciadores, resultando na amplificação de 612, 115 e 622 bandas (loci, respectivamente. A maioria dos loci apresentou-se como polimórfico, mostrando um alto grau de diversidade genética entre os táxons estudados. O dendrograma construído com base nos dados de

  19. The effect of aging on aortic atherosclerotic plaque inflammation and molecular calcification: A FDG and NaF PET CT imaging study

    DEFF Research Database (Denmark)

    Blomberg, Björn; Thomassen, Anders; Hildebrandt, Malene

    2013-01-01

    prospectively assessed by 18-FDG (inflammation) and Sodium 18-Fluoride (Na-18F) (calcification metabolism) PET CT imaging. Global aortic uptake of 18-FDG and Na-18F was quantified by subtracting the blood pool SUVmean from the aortic SUVmax (cSUV) [maximum SUVaorta - mean SUVblood pool]. Calculating regression...

  20. Análise do transcriptoma do estágio invasivo de Fasciola hepatica e sua contribuição na compreensão dos mecanismos moleculares envolvidos no processo de infecção

    OpenAIRE

    Martín Pablo Cancela Sehabiague

    2010-01-01

    Fasciola hepatica é um trematódeo parasita e o agente causador da fasciolose. Esta zoonose causa perdas importantes na produção agropecuária e tem uma crescente incidência na saúde dos seres humanos, principalmente em países em desenvolvimento. Mesmo que existem drogas fasciolicidas, estas não evitam a reinfecção e o surgimento de resistência e, portanto são necessárias novas estratégias de controle. A compreensão dos mecanismos moleculares que envolvem a relação parasito-hospedeiro e os proc...

  1. Comparative molecular-orbital and atomic-orbital study of electron transfer and excitation in He++Na(3s) collisions at energies of 0.05 to 20 keV/amu

    International Nuclear Information System (INIS)

    Fritsch, W.; Kimura, M.; Lane, N.F.

    1990-01-01

    Electron transfer and excitation in 0.05- to 20-keV/amu He + +Na(3s) collisions is studied theoretically within the close-coupling method with two-electron molecular- and atomic-orbital expansion basis sets. Results agree with the trend of other information on this system. Remaining discrepancies that are larger than those in similar contemporary studies of one-electron systems are discussed with reference to the convergence of this two-electron study. Results for the integral alignment parameter A 20 are also presented as a guideline for future experimental study

  2. Molecular analysis of the sea anemone toxin Av3 reveals selectivity to insects and demonstrates the heterogeneity of receptor site-3 on voltage-gated Na+ channels.

    Science.gov (United States)

    Moran, Yehu; Kahn, Roy; Cohen, Lior; Gur, Maya; Karbat, Izhar; Gordon, Dalia; Gurevitz, Michael

    2007-08-15

    Av3 is a short peptide toxin from the sea anemone Anemonia viridis shown to be active on crustaceans and inactive on mammals. It inhibits inactivation of Na(v)s (voltage-gated Na+ channels) like the structurally dissimilar scorpion alpha-toxins and type I sea anemone toxins that bind to receptor site-3. To examine the potency and mode of interaction of Av3 with insect Na(v)s, we established a system for its expression, mutagenized it throughout, and analysed it in toxicity, binding and electrophysiological assays. The recombinant Av3 was found to be highly toxic to blowfly larvae (ED50=2.65+/-0.46 pmol/100 mg), to compete well with the site-3 toxin LqhalphaIT (from the scorpion Leiurus quinquestriatus) on binding to cockroach neuronal membranes (K(i)=21.4+/-7.1 nM), and to inhibit the inactivation of Drosophila melanogaster channel, DmNa(v)1, but not that of mammalian Na(v)s expressed in Xenopus oocytes. Moreover, like other site-3 toxins, the activity of Av3 was synergically enhanced by ligands of receptor site-4 (e.g. scorpion beta-toxins). The bioactive surface of Av3 was found to consist mainly of aromatic residues and did not resemble any of the bioactive surfaces of other site-3 toxins. These analyses have portrayed a toxin that might interact with receptor site-3 in a different fashion compared with other ligands of this site. This assumption was corroborated by a D1701R mutation in DmNa(v)1, which has been shown to abolish the activity of all other site-3 ligands, except Av3. All in all, the present study provides further evidence for the heterogeneity of receptor site-3, and raises Av3 as a unique model for design of selective anti-insect compounds.

  3. Experimental investigation of the EPR parameters and molecular orbital bonding coefficients for VO{sup 2+} ion in NaH{sub 2}PO{sub 4}·2H{sub 2}O single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Kalfaoğlu, Emel [Ondokuz Mayıs University, Faculty of Sciences, Department of Physics, 55139 Kurupelit-Samsun (Turkey); Karabulut, Bünyamin, E-mail: bbulut@omu.edu.tr [Ondokuz Mayıs University, Faculty of Engineering, Department of Computer Engineering, 55139 Kurupelit-Samsun (Turkey)

    2016-09-15

    Electron paramagnetic resonance (EPR) spectra of VO{sup 2+} ions in NaH{sub 2}PO{sub 4}·2H{sub 2}O single crystal have been studied. The spin-Hamiltonian parameters and molecular orbital bonding coefficients were calculated. The angular variation of the EPR spectra shows two different VO{sup 2+} complexes. These are located in different chemical environment and each environment contains four magnetically inequivalent VO{sup 2+} sites. The crystal field around VO{sup 2+} ion is approximately axially symmetric since a strong V=O bond distorts the crystal lattice. Spin Hamiltonian parameters and molecular orbital bonding coefficients were calculated from the EPR data and the nature of bonding in the complex was discussed together.

  4. Ansiedade na performance musical: estudo molecular de associação e validação da escala de \\"K-MPAI

    OpenAIRE

    Sergio de Figueiredo Rocha

    2012-01-01

    A performance musical requer um alto nível de habilidade em diversos parâmetros como coordenação motora, atenção e memória, o que a torna uma atividade particularmente susceptível aos estados de ansiedade. Pesquisas nessa área têm avançado com a introdução de instrumentos específicos para abordar a ansiedade na performance musical (MPA), como é o caso da the Kenny Music Performance Anxiety Inventory (K-MPAI). Estudos recentes apontam polimorfismos genéticos envolvidos na base do quadro de ans...

  5. Molecular Cloning and Characterization of Porcine Na+/K+-ATPase Isoforms α1, α2, α3 and the ATP1A3 Promoter

    DEFF Research Database (Denmark)

    Henriksen, Carina; Kjaer-Sorensen, Kasper; Einholm, Anja Pernille

    2013-01-01

    Na+/K+-ATPase maintains electrochemical gradients of Na+ and K+ essential for a variety of cellular functions including neuronal activity. The α-subunit of the Na+/K+-ATPase exists in four different isoforms (α1–α4) encoded by different genes. With a view to future use of pig as an animal model...... of the arginine with the C-terminus, stabilizing one of the Na+ sites. Quantitative real-time PCR expression analyses of porcine ATP1A1, ATP1A2, and ATP1A3 mRNA showed that all three transcripts are expressed in the embryonic brain as early as 60 days of gestation. Expression of α3 is confined to neuronal tissue....... Generally, the expression patterns of ATP1A1, ATP1A2, and ATP1A3 transcripts were found similar to their human counterparts, except for lack of α3 expression in porcine heart. These expression patterns were confirmed at the protein level. We also report the sequence of the porcine ATP1A3 promoter, which...

  6. Competition among Li+, Na+, K+ and Rb+ Monovalent Ions for DNA in Molecular Dynamics Simulations using the Additive CHARMM36 and Drude Polarizable Force Fields

    OpenAIRE

    Savelyev, Alexey; MacKerell, Alexander D.

    2015-01-01

    In the present study we report on interactions of and competition between monovalent ions for two DNA sequences in MD simulations. Efforts included the development and validation of parameters for interactions among the first-group monovalent cations, Li+, Na+, K+ and Rb+, and DNA in the Drude polarizable and additive CHARMM36 force fields (FF). The optimization process targeted gas-phase QM interaction energies of various model compounds with ions and osmotic pressures of bulk electrolyte so...

  7. Molecular structure determination of cyclooctane by Ab Initio and electron diffraction methods in the gas phase; Determinacao da estrutura molecular do ciclooctano por metodos Ab Initio e difracao de eletrons na fase gasosa

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Wagner B. de [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Quimica

    2000-10-01

    The determination of the molecular structure of molecules is of fundamental importance in chemistry. X-rays and electron diffraction methods constitute in important tools for the elucidation of the molecular structure of systems in the solid state and gas phase, respectively. The use of quantum mechanical molecular orbital ab initio methods offer an alternative for conformational analysis studies. Comparison between theoretical results and those obtained experimentally in the gas phase can make a significant contribution for an unambiguous determination of the geometrical parameters. In this article the determination for an unambiguous determination of the geometrical parameters. In this article the determination of the molecular structure of the cyclooctane molecule by electron diffraction in the gas phase an initio calculations will be addressed, providing an example of a comparative analysis of theoretical and experimental predictions. (author)

  8. Molecular Surface of JZTX-V (β-Theraphotoxin-Cj2a Interacting with Voltage-Gated Sodium Channel Subtype NaV1.4

    Directory of Open Access Journals (Sweden)

    Ji Luo

    2014-07-01

    Full Text Available Voltage-gated sodium channels (VGSCs; NaV1.1–NaV1.9 have been proven to be critical in controlling the function of excitable cells, and human genetic evidence shows that aberrant function of these channels causes channelopathies, including epilepsy, arrhythmia, paralytic myotonia, and pain. The effects of peptide toxins, especially those isolated from spider venom, have shed light on the structure–function relationship of these channels. However, most of these toxins have not been analyzed in detail. In particular, the bioactive faces of these toxins have not been determined. Jingzhaotoxin (JZTX-V (also known as β-theraphotoxin-Cj2a is a 29-amino acid peptide toxin isolated from the venom of the spider Chilobrachys jingzhao. JZTX-V adopts an inhibitory cysteine knot (ICK motif and has an inhibitory effect on voltage-gated sodium and potassium channels. Previous experiments have shown that JZTX-V has an inhibitory effect on TTX-S and TTX-R sodium currents on rat DRG cells with IC50 values of 27.6 and 30.2 nM, respectively, and is able to shift the activation and inactivation curves to the depolarizing and the hyperpolarizing direction, respectively. Here, we show that JZTX-V has a much stronger inhibitory effect on NaV1.4, the isoform of voltage-gated sodium channels predominantly expressed in skeletal muscle cells, with an IC50 value of 5.12 nM, compared with IC50 values of 61.7–2700 nM for other heterologously expressed NaV1 subtypes. Furthermore, we investigated the bioactive surface of JZTX-V by alanine-scanning the effect of toxin on NaV1.4 and demonstrate that the bioactive face of JZTX-V is composed of three hydrophobic (W5, M6, and W7 and two cationic (R20 and K22 residues. Our results establish that, consistent with previous assumptions, JZTX-V is a Janus-faced toxin which may be a useful tool for the further investigation of the structure and function of sodium channels.

  9. Influence of density on radiation-chemical yield of molecular hydrogen formed at radiolysis of aqueous solution of NaOH

    International Nuclear Information System (INIS)

    Jafarov, Y.D.; Hajiyeva, S.R.; Ramazanova, N.K.; Aliyev, S.M.; Alasgarov, A.M.

    2014-01-01

    Full text : In atom and nuclear energy the specialists knowledge about radiation-chemical yield of the initial products formed under the influence of ionizing rays on water is of great importance from the point of security. The radiation-chemical yields of molecular hydrogen have been defined according to the graph and the obtained results

  10. Uso de marcadores moleculares na análise da variabilidade genética em acerola (Malpighia emarginata D.C.

    Directory of Open Access Journals (Sweden)

    SALLA MARIA FERNANDA SPEGIORIN

    2002-01-01

    Full Text Available A acerola (Malpighia emarginata é uma frutífera tropical encontrada nativa na América Central e no Norte da América do Sul, sendo de grande importância econômica e social devido ao seu alto conteúdo de vitamina C (ácido ascórbico. Pomares de acerola têm sido preferencialmente estabelecidos por métodos de propagação vegetiva. No entanto, a propagação sexuada por sementes é igualmente utilizada e permite revelar um alto grau de polimorfismo na cultura, possibilitando a identificação de genótipos portadores de características de interesse agronômico. Vinte e quatro acessos de acerola, pertencentes ao Banco Ativo de Germoplasma da Universidade Estadual de Londrina, foram analisados, usando marcadores RAPD (Random amplified Polymorphic DNA e obtidos com iniciadores (primers de seqüência simples repetidas (SSRs. Um total de 164 e 73 marcadores foram obtidos com primers de RAPD e SSR, respectivamente. Os marcadores obtidos foram analisados, usando o método de agrupamentos UPGMA. A análise comparativa dos dendrogramas gerados com os primers de RAPD e com os primers SSR mostrou que, enquanto alguns acessos se associaram em grupos diferentes, outros apresentaram a mesma associação. Entretanto, maior polimorfismo entre acessos foi detectado com os primers de RAPD. A análise dos resultados revelou a alta variabilidade contida na coleção, permitindo associar o grau de similaridade genética, obtido por marcadores de DNA, com caracteres morfológicos compartilhados entre os acessos.

  11. Synergic effects in the extraction of paracetamol from aqueous NaCl solution by the binary mixtures of diethyl ether and low molecular weight primary alcohols

    Science.gov (United States)

    Nikolić, G. M.; Živković, J. V.; Atanasković, D. S.; Nikolić, M. G.

    2013-12-01

    Liquid-liquid extraction of paracetamol from aqueous NaCl solutions was performed with diethyl ether, 1-propanol, 1-butanol, isobutanol, 1-pentanol, and binary mixtures diethyl ether/1-propanol, diethyl ether/1-butanol, and diethyl ether/isobutanol. Among the pure solvents investigated in this study best extraction efficacy was obtained with 1-butanol. Synergic effects in the extraction with binary mixtures was investigated and compared with some other systems used for the extraction of poorly extractable compounds. Results obtained in this study may be of both fundamental and practical importance.

  12. Molecular orientation via a dynamically induced pulse-train: Wave packet dynamics of NaI in a static electric field

    DEFF Research Database (Denmark)

    Marquetand, P.; Materny, A.; Henriksen, Niels Engholm

    2004-01-01

    We regard the rovibrational wave packet dynamics of NaI in a static electric field after femtosecond excitation to its first electronically excited state. The following quasibound nuclear wave packet motion is accompanied by a bonding situation changing from covalent to ionic. At times when...... the charge separation is present, i.e., when the bond-length is large, a strong dipole moment exists and rotational excitation takes place. Upon bond contraction, the then covalently bound molecule does not experience the external field. This scenario repeats itself periodically. Thus, the vibrational...

  13. Sistema imunitário: Parte I. Fundamentos da imunidade inata com ênfase nos mecanismos moleculares e celulares da resposta inflamatória Immune system: Part I. Fundamentals of innate immunity with emphasis on molecular and cellular mechanisms of inflammatory response

    Directory of Open Access Journals (Sweden)

    Wilson de Melo Cruvinel

    2010-08-01

    Full Text Available O sistema imunológico é constituído por uma intrincada rede de órgãos, células e moléculas, e tem por finalidade manter a homeostase do organismo, combatendo as agressões em geral. A imunidade inata atua em conjunto com a imunidade adaptativa e caracteriza-se pela rápida resposta à agressão, independentemente de estímulo prévio, sendo a primeira linha de defesa do organismo. Seus mecanismos compreendem barreiras físicas, químicas e biológicas, componentes celulares e moléculas solúveis. A primeira defesa do organismo frente a um dano tecidual envolve diversas etapas intimamente integradas e constituídas pelos diferentes componentes desse sistema. A presente revisão tem como objetivo resgatar os fundamentos dessa resposta, que apresenta elevada complexidade e é constituída por diversos componentes articulados que convergem para a elaboração da resposta imune adaptativa. Destacamos algumas etapas: reconhecimento molecular dos agentes agressores; ativação de vias bioquímicas intracelulares que resultam em modificações vasculares e teciduais; produção de uma miríade de mediadores com efeitos locais e sistêmicos no âmbito da ativação e proliferação celulares, síntese de novos produtos envolvidos na quimioatração e migração de células especializadas na destruição e remoção do agente agressor, e finalmente a recuperação tecidual com o restabelecimento funcional do tecido ou órgão.The immune system consists of an intricate network of organs, cells, and molecules responsible for maintaining the body's homeostasis and responding to aggression in general. Innate immunity operates in conjunction with adaptive immunity and is characterized by rapid response to aggression, regardless of previous stimulus, being the organism first line of defense. Its mechanisms include physical, chemical and biological barriers, cellular components, as well as soluble molecules. The organism first line of defense against

  14. Caracterização fenotípica e molecular de amostras de Burkholderia mallei isoladas na Região Nordeste do Brasil Phenotypic and molecular characterization of Burkholderia mallei isolated in northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Karla P.C. Silva

    2009-05-01

    Full Text Available Objetivou-se com este trabalho realizar o estudo bioquímico e molecular de amostras de Burkholderia mallei isoladas de eqüídeos com diagnóstico clínico e sorológico para o mormo e provenientes da Região Metropolitana do Recife-PE e Zona da Mata dos Estados de Alagoas e Pernambuco. Foram realizadas as técnicas microbiológicas para o isolamento e identificação fenotípica de B. mallei e as técnicas moleculares de ribotipagem-PCR e RAPD-PCR. Das oito amostras estudadas, quatro apresentaram pequenas variações fenotípicas. Nas técnicas moleculares, as amostras formaram quatro grupos de diferentes perfis ribotípicos, demonstrando também quatro perfis genotípicos. Houve associação nos resultados da Ribotipagem-PCR e RAPD-PCR. As variações nos perfis ribotípicos e genotípicos foram associadas às diferentes regiões estudadas. De acordo com os resultados obtidos, conclui-se que as pequenas variações bioquímicas não estão associadas aos diferentes perfis moleculares e que essas diferenças demonstram uma heterogeneidade que está associada à procedência das amostras, indicando que a infecção nos animais ocorre por clones diferentes das amostras analisadas.The objective of this paper was to study the molecular performance and phenotypic characterization of Burkholderia mallei isolated from horses with clinical and serological diagnosis of glanders, originating from the Metropolitan District of Recife and Zona da Mata of Pernambuco and Alagoas. The isolation and biochemical identification of B. mallei was carried out by microbiological and molecular techniques of PCR-fingerprinting and RAPD-PCR. From the eight samples studied, four showed little phenotype variations. In the molecular tests, the samples formed 4 groups of different ribotype profiles and 4 genotype profiles. There was some association of PCR-fingerprinting with RAPD-PCR results. It was concluded that the slight biochemical variations were not associated with

  15. The effect of aging on aortic atherosclerotic plaque inflammation and molecular calcification: A FDG and NaF PET CT imaging study

    DEFF Research Database (Denmark)

    Blomberg, Björn; Thomassen, Anders; Hildebrandt, Malene

    2013-01-01

    Objectives: Aging is an important independent determinant of plaque biology. This study aimed to investigate the effect of aging on atherosclerotic plaque inflammation and calcification metabolism. Methods: Thirteen healthy volunteers without traditional cardiovascular risk factors were...... and correlation coefficients summarized the data. Results: A quadratic relationship was observed between aging and aortic 18-FDG and aortic Na-18F avidity. A second order polynomial regression established that aging is a predictor of the degree of aortic plaque inflammation (R = 0.524; F statistic = 4.93; P = 0...... data, a quadratic relationship appears to exist between aging and plaque inflammation. Furthermore, a quadratic relationship was observed between aging and plaque calcification metabolism. In line with these observations, a linear relationship was observed between atherosclerotic plaque inflammation...

  16. Interações moleculares na adesão celular em suportes sólidos e o efeito de fotossensibilizadores porfirínicos

    OpenAIRE

    Patrícia Araújo dos Santos

    2013-01-01

    A adesão celular está ligada à formação e disseminação de metástases, a principal causa de óbito de pacientes diagnosticados com câncer. O objetivo deste trabalho foi investigar in vitro o efeito de fotossensibilizadores na adesão celular. Foram utilizadas porfirinas comerciais (PpIX, CPpI, TSPP, TMPyP e Zn(II)TMPyP) e um fotossensibilizador sintetizado através da ligação de poli-L-lisina à protoporfirina IX (PLLPpIX). A adesão celular foi estudada por RICM, técnica que permite quantificar a ...

  17. Competition among Li+, Na+, K+ and Rb+ Monovalent Ions for DNA in Molecular Dynamics Simulations using the Additive CHARMM36 and Drude Polarizable Force Fields

    Science.gov (United States)

    Savelyev, Alexey; MacKerell, Alexander D.

    2015-01-01

    In the present study we report on interactions of and competition between monovalent ions for two DNA sequences in MD simulations. Efforts included the development and validation of parameters for interactions among the first-group monovalent cations, Li+, Na+, K+ and Rb+, and DNA in the Drude polarizable and additive CHARMM36 force fields (FF). The optimization process targeted gas-phase QM interaction energies of various model compounds with ions and osmotic pressures of bulk electrolyte solutions of chemically relevant ions. The optimized ionic parameters are validated against counterion condensation theory and buffer exchange-atomic emission spectroscopy measurements providing quantitative data on the competitive association of different monovalent ions with DNA. Comparison between experimental and MD simulation results demonstrates that, compared to the additive CHARMM36 model, the Drude FF provides an improved description of the general features of the ionic atmosphere around DNA and leads to closer agreement with experiment on the ionic competition within the ion atmosphere. Results indicate the importance of extended simulation systems on the order of 25 Å beyond the DNA surface to obtain proper convergence of ion distributions. PMID:25751286

  18. New perspectives in the Fischer-Tropsch synthesis using cobalt supported on mesoporous molecular sieves; Novas perspectivas na sintese de Fischer-Tropsch usando cobalto suportado em peneiras moleculares mesoporosas

    Energy Technology Data Exchange (ETDEWEB)

    Souza, M.J.B.; Silva, A.O.S. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Engenharia Quimica; Fernandes Junior, V.J.; Araujo, A.S. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Quimica

    2004-07-01

    The conversion of synthesis gas to liquid products via Fischer-Tropsch synthesis (FTS) is an important process in the generation of clean fuels of sulfur and nitrogen compounds. Catalysts based on iron are very used in the conventional process due its cheap manufacture price. Recently the use of cobalt as promoter gave good results. MCM-41 mesoporous materials were discovered by Mobil scientists in the nineties and ever since they have great successes as support and catalyst in several processes of the oil industry as catalytic cracking, reformer and hydrotreating. In this work are presented new alternatives for FTS with the use of cobalt supported on molecular sieves of the type MCM-41. A comparative study with the usual catalysts based on silica was accomplished with different levels of cobalt. (author)

  19. Reclassification of Candida guilliermondii FTI 20037 as Candida tropicalis based on molecular phylogenetic analysis Reclassificação de Candida guilliermondii FTI 20037 como Candida tropicalis baseada na análise filogenética molecular

    Directory of Open Access Journals (Sweden)

    Luanne Helena Augusto Lima

    2003-11-01

    Full Text Available Yeasts of the genus Candida are of clinical importance and also have many industrial applications, mainly in the food industry. The yeast Candida guilliermondii FTI 20037 has been extensively studied in order to establish a biotechnological process for the production of xylitol. The goal of this study was to verify the taxonomic classification of this strain based on the analysis of rDNA sequences and the xyl1 gene. DNA fragments from these sequences were amplified by PCR and BLAST analysis revealed strong identity with the corresponding sequences from Candida tropicalis. Based on these results, we propose that C. guilliermondii FTI 20037 must be reclassified as C. tropicalis.As leveduras do gênero Candida possuem tanto importância clínica como diversas aplicações industriais, principalmente na indústria de alimentos. A levedura Candida guilliermondii FTI 20037 tem sido exaustivamente estudada pois pretende-se utilizá-la no estabelecimento de um processo biotecnológico para a produção de xilitol. O objetivo deste trabalho foi verificar a classificação taxonômica desta levedura por análise de sequências do rDNA e do gene xyl1. Fragmentos correspondentes a estas regiões foram amplificados por PCR e a análise destas sequências por BLAST revelou alta identidade com sequências correspondentes de Candida tropicalis. Estes resultados nos levam a propor que C. guilliermondii FTI 20037 deva ser reclassificada como C. tropicalis.

  20. Seleção tradicional e associada a marcadores moleculares na avaliação genética animal Traditional and associated selection with molecular markers in the genetic evaluation of animals

    Directory of Open Access Journals (Sweden)

    Paulo Luiz Souza Carneiro

    2006-04-01

    Full Text Available O objetivo deste trabalho foi comparar a seleção, utilizando valores genéticos preditos pelo BLUP clássico (BLUP, BLUP marcadores (BLUPM e pela seleção individual (SI, usando simulação com o programa Genesys. Para obter a matriz de similaridade genética utilizada no BLUPM, foram simulados cem marcadores moleculares do tipo microssatélite (SSR - Simple Sequence Repeat, por meio de um coeficiente de similaridade correspondente à distância euclideana média para dados quantitativos. A fim de comparar os diferentes métodos, utilizaram-se populações com tamanho efetivo de 66,66 e média de 30 repetições, avaliando-se os valores fenotípicos médios. Os ganhos ao longo das 20 gerações de seleção foram maiores para o BLUP em relação ao BLUPM, e este foi superior à SI. Quanto ao ganho obtido nas cinco primeiras gerações, o BLUPM apresentou ganhos semelhantes ao BLUP e superiores à SI. Diferentes sistemas de acasalamento dos reprodutores selecionados não revelaram diferenças em ganho genético nos métodos baseados no BLUP.The objective of this work was to compare selection based on breeding values predicted by classical best linear unbiased prediction (BLUP, BLUP associated with molecular markers (BLUPM and individual selection (IS using data simulated with the Genesys program. To obtain the genetic similarity matrix to be used in BLUPM, a hundred microsatellite markers (simple sequence repeats were simulated using a similarity coefficient corresponding to the mean Euclidean distance between quantitative data. The different selection methods were compared using populations of an effective size of 66.66 and a mean of 30 repetitions, and mean phenotypic values were determined. Genetic gain obtained over 20 generations of selection was higher for BLUP than BLUPM, which in turn was superior to IS. Similar genetic gains were obtained for BLUPM and BLUP only when the gain for the first five generations was considered, and these

  1. Uso da bioinformática na diferenciação molecular da Entamoeba histolytica e Entamoeba díspar - DOI: 10.4025/actascihealthsci.v30i2.2375 Molecular discrimination of Entamoeba histolytica and Entamoeba dispar by bioinformatics resources - DOI: 10.4025/actascihealthsci.v30i2.2375

    Directory of Open Access Journals (Sweden)

    Débora Sommer

    2008-12-01

    Full Text Available Amebíase invasiva, causada por Entamoeba histolytica, é microscopicamente indistinguível da espécie não-patogênica Entamoeba dispar. Com auxílio de ferramentas de bioinformática, objetivou-se diferenciar Entamoeba histolytica e Entamoeba dispar por técnicas moleculares. A análise foi realizada a partir do banco de dados da National Center for Biotechnology Information; pela pesquisa de similaridade de sequências, elegeu-se o gene da cisteína sintase. Um par de primer foi desenhado (programa Web Primer e foi selecionada a enzima de restrição TaqI (programa Web Cutter. Após a atuação da enzima, o fragmento foi dividido em dois, um com 255 pb e outro com 554 pb, padrão característico da E. histolytica. Na ausência de corte, o fragmento apresentou o tamanho de 809 pb, referente à E. dispar.Under microscopic conditions, the invasive Entamoeba histolytica is indistinguishable from the non-pathogenic species Entamoeba dispar. In this way, the present study was carried out to determine a molecular strategy for discriminating both species by the mechanisms of bioinformatics. The gene cysteine synthetase was considered for such a purpose by using the resources of the National Center for Biotechnology Information data bank in the search for similarities in the gene sequence. In this way, a primer pair was designed by the Web Primer program and the restriction enzyme TaqI was selected by the Web Cutter software program. The DNA fragment had a size of 809 bp before cutting, which is consistent with E. dispar. The gene fragment was partitioned in a first fragment with 255 bp and a second one with 554 bp, which is similar to the genetic characteristics of E. histolytica.

  2. Primera identificación molecular del transgen de la proteína fluorescente roja (RFP en peces Cebra (Danio rerio transgénicos ornamentales introducidos en el Perú

    Directory of Open Access Journals (Sweden)

    Carlos Scotto

    2013-01-01

    Full Text Available En el presente trabajo se identificó por primera vez peces Cebra transgénicos (Danio rerio fluorescentes de color rojo, naranja y rosado introducidos al territorio peruano de acuarios locales utilizando la técnica de PCR para amplificar el transgen RFP perteneciente a la anémona marina Discosoma spp. Se encontró una expresión génica diferencial del transgen de la proteína fluorescente roja (RFP que determinaría una gradiente de bioluminiscencia para cada color entre los peces OVM analizados. Se realizó un análisis de secuencias de las dos variantes de la RFP junto con las seis variantes de la GFP de proteínas fluorescentes existentes en el Genbank que podrían ayudar a identificar rápidamente si son nuevos genes o si son nuevas variantes de éstas proteínas fluorescentes y que podrían ser utilizadas en otros OVMs hidrobiológicos a futuro. De este modo, desarrollar y optimizar las medidas de bioseguridad mediante su oportuna detección a nivel genético molecular.

  3. Utilização de microssatélites e RAPD na caracterização molecular de acessos de Paspalum urvillei Steudel Genetic diversity among accesses of Paspalum urvillei Steudel estimated by microssatelites and RAPD markers

    Directory of Open Access Journals (Sweden)

    Joaquim Taizo Sawasato

    2008-08-01

    Full Text Available Este estudo foi realizado com o objetivo de verificar a diversidade genética na coleção de acessos de P. urvillei do Departamento de Plantas Forrageiras e Agrometeorologia (DPFA da Faculdade de Agronomia (UFRG visando sua utilização em futuros trabalhos de seleção. Foram avaliados 64 acessos provenientes do Rio Grande do Sul, 1 de Xanxerê, Santa Catarina, três de Curitiba, Paraná, e 1 da Argentina. A diversidade genética foi analisada por meio de marcadores do tipo RAPD e SSR. Utilizaram-se dez primers para marcadores RAPD, o que possibilitou obter 56 bandas polimórficas e 11 grupos no dendrograma com similaridade média de 0,70. Na técnica de SSR, foram utilizados sete primers e obtidas 28 bandas polimórficas, formando sete grupos no dendrograma com similaridade média de 0,66. Ambos os marcadores foram eficientes para o agrupamento de acessos coletados. O uso de maior número de primers para gerar mais bandas polimórficas foi necessário para obtenção de fingerprintsgenômicos dos indivíduos similares. Os dendrogramas gerados neste estudo dão subsídios para futuros cruzamentos de gerações parentais contrastantes ou similares no melhoramento de Paspalum urvillei.The aim of this study was to estimate the genetic diversity among accesses of P. urvillei of Departamento de Plantas Forrageiras e Agrometeorologia (DPFA of the College of Agronomy - UFRGS and to evaluate their use in selection programs. Sixty four accesses from different cities of the Southern Region of Brazil (Rio Grande do Sul, Santa Catarina and Parana States and from Argentine were analyzed by RAPD and SSR molecular markers. Ten primers of RAPD markers were used and resulted in 56 polymorphic bands and 11 groups in a dendrogram with average similarity 0.70. Seven primers were used for the SSR technique and resulted in 28 polymorphic bands and seven groups in a dendrogram with average similarity 0.66. Both markers were efficient on grouping the accesses

  4. Moldagem por compressão a frio do polietileno de ultra alto peso molecular. Parte 1: influência do tamanho, distribuição e morfologia da partícula na densidade a verde Cold compression molding of ultra high molecular weight polyethylene. Part 1: influence of the size, distribution and morphology of particles on the green density

    Directory of Open Access Journals (Sweden)

    Bernadete A. Bittencourt

    2009-01-01

    Full Text Available Neste trabalho foram investigadas as características de amostras de pó de polietileno de ultra alto peso molecular (PEUAPM, tais como porosidade, morfologia, tamanho médio e distribuição de partícula, que são importantes na moldagem por compressão a frio. Também foi avaliada a influência dessas características na densidade a verde de pré-formas. As amostras dos pós foram caracterizadas por calorimetria diferencial de varredura (DSC, análise granulométrica, absorção de óleo, área superficial, porosimetria de mercúrio, fluidez do pó, densidade de compactação, densidade aparente e microscopia eletrônica de varredura (MEV. Através das técnicas de caracterização estudadas ficou evidenciado que as características da partícula citadas anteriormente, assim como o parâmetro de densificação (DP, que é função direta da porosidade interparticular, favorecem a densidade a verde relativa (DVR e consequentemente a tensão de resistência à flexão (TRF.In this paper an investigation was made of the characteristics of Ultra High Molecular Weight Polyethylene (UHMWPE powder samples, including porosity, particles average size, size distribution and morphology, which are important in cold compression molding. The influence of these characteristics on the green density of molded pre-shapes was also investigated. The UHMWPE powder samples were characterized by Differential Scanning Calorimetry (DSC, granulometric analysis, oil absorption, surface area, mercury porosity, density compaction, apparent density and Scanning Electron Microscopy (SEM. The characterization techniques used demonstrate that the UHMWPE particles characteristics cited above as well as the densification parameter (DP, which is a direct function of the interparticles porosity, affect the relative green density (RGD and hence, the flexural tensile strength (FTS.

  5. Variantes moleculares en el gen L1 del virus del papiloma humano tipo 16, y regiones de la proteína L1 probablemente involucradas en la interacción virus-célula epitelial

    Directory of Open Access Journals (Sweden)

    María Mercedes Bravo

    2004-03-01

    Full Text Available

    La infección con virus del papiloma humano de alto riesgo es considerada como el principal factor de riesgo en el desarrollo del cáncer de cuello uterino. Entre los HPV de alto riesgo, el tipo 16 es el más frecuente tanto en mujeres con citología normal, como en mujeres con lesiones premalignas y en cáncer invasivo. Se ha demostrado la existencia de variaciones en la secuencia del genoma de HPV16, estos polimorfismos se han agrupado en cinco ramas filogenéticas denominadas según su distribución geográfica: Europeas (E, Asiaticas-Americanas (AA, Asiáticas (As, Africanas (Af y Norteamericanas (NA; determinadas por sustituciones nucleotídicas en los genes E6, L1 y L2 y la región larga de control.

    Varios estudios han sugerido que las variantes no Europeas son más agresivas que las Europeas, esto puede ser el reflejo de una interacción diferente con el huésped y por tanto implicar diferencias en el resultado final de la infección (mayor persistencia o mayor oncogenicidad.

    Particularmente se ha demostrado que las variaciones en la secuencia de aminoácidos de la proteína L1, la proteína principal de la cápside viral, pueden modificar las epítopes neutralizantes del virus afectando la efectividad de la respuesta inmune, también estas variaciones pueden afectar la capacidad de ensamble de las cápsides y la afinidad por receptores a nivel epitelial.

    El propósito de este estudio fue identificar las variaciones moleculares del gen L1 de HPV16 en aislamientos provenientes de cepillados cervicales de mujeres colombianas con citología normal y con cáncer de cuello uterino, con el fin de analizar si existen variaciones que alteren las regiones

  6. Human T-cell Lymphotropic Virus types I and II (HTLV-I/II in French Guiana: clinical and molecular epidemiology Os Vírus T-Linfotrópicos Humanos tipo I (HTLV-I e tipo II (HTLV-II na Guiana Francesa: epidemiologia clínica e molecular

    Directory of Open Access Journals (Sweden)

    Mirdad Kazanji

    2003-10-01

    Full Text Available We review here the epidemiological studies performed by our group on human retrovirus HTLV-I and HTLV-II infections and the associated diseases in French Guiana since 1984. French Guiana is an overseas French administrative district located between Brazil and Surinam. Its population is characterized by a large variety of ethnic groups, including several populations of African origin and various populations of Amerindian origin. Several epidemiological studies of large samples of pregnant women and in remote villages showed that HTLV-I is highly endemic in this area but is restricted to groups of African origin, especially the Noir-Marrons. In this endemic population, the results of segregation analysis in a genetic epidemiological study were consistent with the presence of a dominant major gene predisposing to HTLV-I infection, especially in children. In contrast, HTLV-II infection appears to be rare in French Guiana, having been found in only a few individuals of Brazilian origin. From a molecular point of view, the HTLV-I strains present in the Noir-Marrons, Creoles and Amerindians appear to originate from Africa, as they belong to the large cosmopolitan molecular subtype A.Os autores apresentam uma revisão dos estudos epidemiológicos realizados pelo seu grupo de pesquisa sobre a infecção pelos vírus T-linfotrópicos humanos tipo I (HTLV-I e tipo II (HTLV-II e doenças associadas na Guiana Francesa, desde 1984. A Guiana Francesa é um Departamento de Ultramar da França, situado entre o Brasil e o Suriname. A população é caracterizada por uma grande variedade de grupos étnicos, incluindo diversas comunidades de origem africana e outras de origem indígena. Diversos inquéritos epidemiológicos sobre gestantes e em aldeias remotas mostraram que o HTLV-I é altamente endêmico nessas áreas, mas que o vírus é restrito a grupos de origem africana, particularmente os Noir-Marrons. Nessa população endêmica, os resultados de uma an

  7. Glutamate Water Gates in the Ion Binding Pocket of Na(+) Bound Na(+), K(+)-ATPase

    DEFF Research Database (Denmark)

    Han, Minwoo; Kopec, Wojciech; Solov'yov, Ilia A

    2017-01-01

    III is always protonated. Glutamic acid residues in the three binding sites act as water gates, and their deprotonation triggers water entry to the binding sites. From DFT calculations of Na(+) binding energies, we conclude that three protons in the binding site are needed to effectively bind Na......The dynamically changing protonation states of the six acidic amino acid residues in the ion binding pocket of the Na(+), K(+) -ATPase (NKA) during the ion transport cycle are proposed to drive ion binding, release and possibly determine Na(+) or K(+) selectivity. We use molecular dynamics (MD......(+) from water and four are needed to release them in the next step. Protonation of Asp926 in site III will induce Na(+) release, and Glu327, Glu954 and Glu779 are all likely to be protonated in the Na(+) bound occluded conformation. Our data provides key insights into the role of protons in the Na...

  8. Načrtovan porod na domu

    OpenAIRE

    Todorović, Tamara; Takač, Iztok

    2017-01-01

    Izhodišča: Porod na domu je sicer star toliko kot človeštvo, pa vendar v veliki večini srednje in visoko razvitih držav prevladuje mnenje, da so zaradi nepredvidljivosti zapletov porodnišnice najbolj varno okolje za rojevanje. Kljub temu obstaja peščica držav, v katerih je porod na domu integriran v sistem zdravstvenega varstva (npr. Nizozemska, Velika Britanija, Kanada). Pri porodih na domu ločimo nenačrtovane in načrtovane porode na domu, slednje pa lahko nadalje razdelimo še na porode s sp...

  9. Metal cluster fission: jellium model and Molecular dynamics simulations

    DEFF Research Database (Denmark)

    Lyalin, Andrey G.; Obolensky, Oleg I.; Solov'yov, Ilia

    2004-01-01

    Fission of doubly charged sodium clusters is studied using the open-shell two-center deformed jellium model approximation and it ab initio molecular dynamic approach accounting for all electrons in the system. Results of calculations of fission reactions Na_10^2+ --> Na_7^+ + Na_3^+ and Na_18...

  10. Investigação da influência do processamento na dinâmica molecular de nanocompósitos de policarbonato e argila organofílica obtidos via intercalação por fusão On the influence of processing parameters on the molecular dynamics of melt intercalated polycarbonate-clay nanocomposites

    Directory of Open Access Journals (Sweden)

    Elton J. da R. Rodrigues

    2012-01-01

    Full Text Available Nanocompósitos baseados em policarbonato e argila organofílica foram obtidos pelo método de intercalação por fusão em câmara de mistura sob diferentes valores de torque e temperatura. A influência desses parâmetros na qualidade da dispersão da argila na matriz polimérica foi investigada por ressonância magnética nuclear (RMN de baixo campo, empregando o tempo de relaxação longitudinal, T1H, e por difração de raios X. As diferenças nos tempos de relaxação longitudinal e nos padrões de difração de raios X foram correlacionadas com a formação de domínios com mobilidades distintas. O nanomaterial formado apresentou morfologia intercalada com afastamento crescente das camadas de argila, conforme as condições de processamento se tornavam mais severas. A RMN ¹H mostrou que tanto o cisalhamento quanto a temperatura afetaram a mobilidade das cadeias poliméricas, explicitando a homogeneidade crescente da distribuição dos domínios de relaxação, de acordo com o aumento do torque e da temperatura.Polycarbonate-organofilic clay nanocomposites were obtained via the melt intercalation method in the blending chamber of a torque rheometer, under distinct values of shear and temperature. The influence of those processing parameters on the clay dispersion in the polymer matrix was probed by low-field nuclear magnetic resonance (NMR, using the T1H measurement technique and by wide angle X-ray scattering (WAXS. The differences in longitudinal relaxation times and in the X-ray reflection patterns were correlated with the formation of relaxation domains with particular molecular mobility, as progressively larger intercalated morphologies were found in the nanocomposites due to the increase of shear stress and temperature. ¹H NMR has shown that both shearing and temperature have played a fundamental part on the polymer chains mobility, which explains the increase in the domain´s homogeneity following the increment of those processing

  11. Classic and molecular study of Giardia duodenalis in children from a daycare center in the region of Presidente Prudente, São Paulo, Brazil Estudo clássico e molecular de Giardia duodenalis em crianças atendidas em uma creche na região de Presidente Prudente, São Paulo, Brasil

    Directory of Open Access Journals (Sweden)

    Nair Toshiko Tashima

    2009-02-01

    submetidos a exames parasitológicos de fezes. Destes, sete mães e nove irmãos apresentaram G. duodenalis, enquanto os pais, funcionários da creche e animais de estimação (cães não apresentaram o parasita. Além dos 15 casos com G. duodenalis, outras 23 crianças apresentaram outros enteroparasitas (Entamoeba coli, Endolimax nana, Enterobius vermicularis, Ascaris lumbricoides e Trichuris trichiura. As amostras contendo cistos de G. duodenalis das crianças e de seus parentes foram submetidas à análise molecular por RAPD após extração do DNA genômico e amplificação de um fragmento de uma região do rDNA 18S por PCR. Entre os 31 isolados de G. duodenalis (crianças e suas respectivas mães e irmãos, concluiu-se que a transmissão dos parasitas ocorreu entre as crianças, provavelmente durante seu convívio na creche, mas não foi decorrente do convívio familiar ou animais de estimação.

  12. Determinação da estrutura molecular do ciclooctano por métodos ab initio e difração de elétrons na fase gasosa

    OpenAIRE

    De Almeida,Wagner B.

    2000-01-01

    The determination of the molecular structure of molecules is of fundamental importance in chemistry. X-rays and electron diffraction methods constitute in important tools for the elucidation of the molecular structure of systems in the solid state and gas phase, respectively. The use of quantum mechanical molecular orbital ab initio methods offer an alternative for conformational analysis studies. Comparison between theoretical results and those obtained experimentally in the gas phase can ma...

  13. Marcadores moleculares RAPD e descritores morfológicos na avaliação da diversidade genética de goiabeiras (Psidium guajava L. = RAPD molecular markers and morphological descriptors in the evaluation of genetic diversity of guava (Psidium guajava L.

    Directory of Open Access Journals (Sweden)

    Aroldo Gomes Filho

    2010-10-01

    Full Text Available O conhecimento da variabilidade genética e fenotípica entre diferentes acessos de goiabeiras é importante para se apoiar programas de melhoramento dessa espécie na região Norte Fluminense que carece de novas culturas capazes de gerar renda aos produtores locais. O objetivo deste trabalho foi avaliar a divergência genética entre seis cultivares e 19 acessos de goiabeiras, por meio de marcadores moleculares RAPD e características morfoagronômicas. Foram obtidas 117 marcas polimórficas, utilizando-se 28 iniciadores. Os resultados mostraram uma concordância parcial entre os métodos de agrupamentos estudados, com a formação de 12 grupos. O acesso Vita 3 e o acesso 6 foram os mais divergentes, apresentando distância genética de 0,663. A análise comparativa dos agrupamentos revelou que os marcadores RAPD e os descritores morfológicos foram eficientes para discriminação dos acessos e que houve variabilidade genética potencial para uso em Programa de Melhoramento Genético.The knowledge of the genetic and phenotypic variability among different accessions of guava is important for supporting improvement programs of this specie in northern Rio de Janeiro state, which needs new cultivars able to generate income for local farmers. This work aimed to evaluate the genetic divergence among six cultivars and 19 accessions of guava via RAPD molecular markers and morphologicalcharacteristics. One hundred and seventeen polymorphic markers were obtained from 28 primers. The results showed a partial agreement between the methods of studied groupings, with the formation of 12 groups. The accessions ‘Vita 3’and ‘6’ were the most divergent, showing genetic distance of 0.663. The comparative analysis of groupings showed that RAPD markers and morphological descriptors were effective in discriminating the accessions and to show potentialgenetic variability useful in genetic improvement programs.

  14. Laser-induced ionization of Na vapor

    International Nuclear Information System (INIS)

    Wu, R.C.Y.; Judge, D.L.; Roussel, F.; Carre, B.; Breger, P.; Spiess, G.

    1982-01-01

    The production of Na 2 + ions by off-resonant laser excitation in the 5800-6200A region mainly results from two-photon absorption by the Na 2 molecule to highly excited gerade states followed by (a) direct ionization by absorbing a third photon or (b) coupling to the molecular Na 2 D 1 PIμ Rydberg state which is subsequently ionized by absorbing a third photon. This mechanism, i.e., a two-photon resonance three photon ionization process, explains a recent experimental observation of Roussel et al. It is suggested that the very same mechanism is also responsible for a similar observation reported by Polak-Dingels et al in their work using two crossed Na beams. In the latter two studies the laser-induced associative ionization processes were reported to be responsible for producing the Na 2 + ion. From the ratio of molecular to atomic concentration in the crossed beam experiment of Polak-Dingels et al we estimate that the cross section for producing Na 2 + through laser-induced associative ionization is at least four orders of magnitude smaller than ionization through the two-photon resonance three photon ionization process in Na 2 molecules

  15. Modelagem molecular da interação entre a proteína de fusão do vírus sincicial respiratório humano e inibidores da ação viral. -

    OpenAIRE

    Cravo, Haroldo de Lima Pimentel [UNESP

    2012-01-01

    O Vírus Sincicial Respiratório Humano (hRSV) foi identificado em 1957 e mesmo após vários anos de investigação, nenhuma vacina foi desenvolvida. Acredita-se que a chave de inibição da ação viral são suas glicoproteínas de membrana, em especial a proteína de fusão (F), que com auxílio da proteína de ligação (G), é responsável pela instalação do hRSV na célula hospedeira. Há evidências experimentais de que compostos como flavonóides e glicosaminoglicanos podem diminuir a infecção viral, sendo e...

  16. Biologia, conhecimento e consciência: articulações possíveis na construção da aprendizagem = Biology, knowledge and consciousness: possible links in learning construction = Biología, conocimiento y conciencia: posibles conexiones en la construcción del aprendizaje

    Directory of Open Access Journals (Sweden)

    Flach, Pâmela Ziliotto Sant'Anna

    2016-01-01

    Full Text Available Neste trabalho apresenta-se uma discussão acerca das contribuições da neurobiologia e da epistemologia genética aos processos de construção do conhecimento e da consciência. Discute-se, também, como tais processos se relacionam com os mecanismos de conservação da homeostase dos organismos. Para isso, debruçou-se sobre obras de António Damásio e Jean Piaget na tentativa de compreender as articulações entre organismo e sujeito epistêmico como protagonistas dos atos de manter-se vivo, conhecer e tomar consciência. Seja no âmbito orgânico ou no cognitivo, a manutenção da vida passa pela interação constante e permanente entre organismo e meio. Concebe-se essa interação como fonte de sempre novos desequilíbrios que abrem espaço para novas experiências que, por sua vez, geram novos desenvolvimentos afetivos ou cognitivos. Com isso, são possibilitadas novas aprendizagens, escolares ou não, que concorrem para a sobrevivência em todos os níveis da vida humana

  17. Influência da terapia com laser de baixa potência e hialuronato de sódio de alto peso molecular na ATM de ratos, com artrite, após indução por CFA

    OpenAIRE

    George Azevêdo Lemos

    2015-01-01

    Resumo: A Disfunção temporomandibular (DTM) é uma expressão coletiva que engloba vários sinais e sintomas clínicos relacionados aos músculos da mastigação, articulações temporomandibulares (ATMs) e estruturas associadas. As principais queixas relatadas são ruídos e dor na região da ATM, com maior prevalência em adultos jovens, especialmente mulheres. A inflamação intra-articular é considerada uma das mais importantes fontes de dor nesta disfunção. O processo inflamatório pode se localizar na ...

  18. Suppression of Na interstitials in Na-F codoped ZnO

    Science.gov (United States)

    Huo, Wenxing; Mei, Zengxia; Tang, Aihua; Liang, Huili; Du, Xiaolong

    2018-04-01

    Controlling the formation of interstitial Na (Nai) self-compensating defects has been a long-term physics problem for effective Na doping in ZnO. Herein, we present an experimental approach to the suppression of Nai defects in ZnO via Na and F codoping under an oxygen-rich condition during the molecular beam epitaxy growth process. It is found that the incorporation of such large numbers of Na and F dopants (˜1020 cm-3) does not cause an obvious influence on the lattice parameters. Hall-effect measurements demonstrate that F doping efficiently raises the Fermi level (EF) of ZnO films, which is expected to make the formation energy of Nai and NaZn increase and decrease, respectively. Most of the Na atoms occupy the substitutional Zn sites, and the formation of Nai is suppressed consequently. Secondary ion mass spectrometry measurements reveal that F and Na atoms are tightly bonded together due to their strong Coulomb interaction. The enhanced deep level emission (DLE) in ZnO:Na-F is ascribed to the considerable amount of isolated Zn vacancy (VZn) defects induced by the elevated EF and the formation of neutral (" separators="| FO + - Na Zn - ) 0 complexes. On the other hand, formation of (" separators="| FO + - VZn 2 - ) - complexes in ZnO:F exhausts most of the isolated Zn vacancies, leading to the disappearance of the DLE band.

  19. Rescue of Na+ affinity in aspartate 928 mutants of Na+,K+-ATPase by secondary mutation of glutamate 314.

    Science.gov (United States)

    Holm, Rikke; Einholm, Anja P; Andersen, Jens P; Vilsen, Bente

    2015-04-10

    The Na(+),K(+)-ATPase binds Na(+) at three transport sites denoted I, II, and III, of which site III is Na(+)-specific and suggested to be the first occupied in the cooperative binding process activating phosphorylation from ATP. Here we demonstrate that the asparagine substitution of the aspartate associated with site III found in patients with rapid-onset dystonia parkinsonism or alternating hemiplegia of childhood causes a dramatic reduction of Na(+) affinity in the α1-, α2-, and α3-isoforms of Na(+),K(+)-ATPase, whereas other substitutions of this aspartate are much less disruptive. This is likely due to interference by the amide function of the asparagine side chain with Na(+)-coordinating residues in site III. Remarkably, the Na(+) affinity of site III aspartate to asparagine and alanine mutants is rescued by second-site mutation of a glutamate in the extracellular part of the fourth transmembrane helix, distant to site III. This gain-of-function mutation works without recovery of the lost cooperativity and selectivity of Na(+) binding and does not affect the E1-E2 conformational equilibrium or the maximum phosphorylation rate. Hence, the rescue of Na(+) affinity is likely intrinsic to the Na(+) binding pocket, and the underlying mechanism could be a tightening of Na(+) binding at Na(+) site II, possibly via movement of transmembrane helix four. The second-site mutation also improves Na(+),K(+) pump function in intact cells. Rescue of Na(+) affinity and Na(+) and K(+) transport by second-site mutation is unique in the history of Na(+),K(+)-ATPase and points to new possibilities for treatment of neurological patients carrying Na(+),K(+)-ATPase mutations. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Parametri za procena na kvalitetot na polietilenska i na polipropilenska ambalaza i na gumeni zatvoraci nameneti za farmacevtski preparati

    Directory of Open Access Journals (Sweden)

    Liljana Ugrinova

    2002-03-01

    Full Text Available Napraven e pregled na parametrite za procena na kvalitetot na polietilenska i na polipropilenska ambalaza i na gumeni zatvoraci nameneti za farmacevtski preparati. Za procena na kvalitetot na ispituvaniot materijal bea izvrseni fizicki, hemiski i bioloski ispituvanja spored postapkite dadeni vo Ph. Eur., DIN i spored DIN ISO standardite. Baranjata za kvalitet na ovoj vid ambalaza propisani spored Ph. Eur., DIN i DIN ISO standardite se razlikuvaat vo odnos na predvidenite parametri za fizicki, za hemiski i za bioloski ispituvanja. Isto taka, propisani se i razlicni granici na dozvoleno otstapuvanje na oddelni parametri.

  1. Influence of ionizing radiation on synthesis and molecular heterogeneity of catalase in tissue culture of Rauwolfia serpentina; Vliyanie ioniziruyushchego izlucheniya na biosintez i molekulyarnuyu geterogennost' katalazy v kul'ture tkani Rauwolfia serpentina

    Energy Technology Data Exchange (ETDEWEB)

    Komov, V P; Bespalova, E V; Strelkova, M A [Sankt-Peterburgskaya Khimiko-Farmatsevticheskaya Akademiya, Kafedra Biologii, S.-Peterburg (Russian Federation)

    1998-12-01

    Changes in activity and molecular heterogeneity of catalase in tissue culture of Rauwolfia serpentina following irradiation in early growth period at the doses of 8 and 50 Gy has been studied. Ionizing radiation accelerate the synthesis and degradation rates of catalase and total protein. A comparative study of changes in enzyme and protein turnover during growth on irradiated and non-irradiated medium has been made.

  2. Mid-infrared supercontinuum covering the 1.4–13.3 μm molecular fingerprint region using ultra-high NA chalcogenide step-index fibre

    DEFF Research Database (Denmark)

    Petersen, Christian Rosenberg; Møller, Uffe Visbech; Kubat, Irnis

    2014-01-01

    -power laser diodes, quantum cascade lasers and synchrotron radiation have precluded mid-infrared applications where the spatial coherence, broad bandwidth, high brightness and portability of a supercontinuum laser are all required. Here, we demonstrate experimentally that launching intense ultra-short pulses...... the potential of fibres to emit across the mid-infrared molecular ‘fingerprint region’, which is of key importance for applications such as early cancer diagnostics3, gas sensing and food quality control....

  3. Molecular-beam scattering

    International Nuclear Information System (INIS)

    Vernon, M.F.

    1983-07-01

    The molecular-beam technique has been used in three different experimental arrangements to study a wide range of inter-atomic and molecular forces. Chapter 1 reports results of a low-energy (0.2 kcal/mole) elastic-scattering study of the He-Ar pair potential. The purpose of the study was to accurately characterize the shape of the potential in the well region, by scattering slow He atoms produced by expanding a mixture of He in N 2 from a cooled nozzle. Chapter 2 contains measurements of the vibrational predissociation spectra and product translational energy for clusters of water, benzene, and ammonia. The experiments show that most of the product energy remains in the internal molecular motions. Chapter 3 presents measurements of the reaction Na + HCl → NaCl + H at collision energies of 5.38 and 19.4 kcal/mole. This is the first study to resolve both scattering angle and velocity for the reaction of a short lived (16 nsec) electronic excited state. Descriptions are given of computer programs written to analyze molecular-beam expansions to extract information characterizing their velocity distributions, and to calculate accurate laboratory elastic-scattering differential cross sections accounting for the finite apparatus resolution. Experimental results which attempted to determine the efficiency of optically pumping the Li(2 2 P/sub 3/2/) and Na(3 2 P/sub 3/2/) excited states are given. A simple three-level model for predicting the steady-state fraction of atoms in the excited state is included

  4. Na, K-ATPase as signaling transducer

    OpenAIRE

    Li, Juan

    2007-01-01

    It is now generally agreed that Na,K-ATPase (NKA), in addition to its role in the maintenance of Na+ and K+ gradients across the cell membrane, is a signal transducer. Our group has identified a novel signaling pathway where NKA interact with IP3R to form a signaling microdomain. Ouabain, a specific ligand of NKA, activates this pathway, triggers slow Ca2+ oscillations and activates NF-κB. In current study, the molecular mechanisms and some important downstream effects of NK...

  5. Magnetismo Molecular (Molecular Magentism)

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Mario S [Universidade Federal Fluminense, Brasil; Moreira Dos Santos, Antonio F [ORNL

    2010-07-01

    The new synthesis processes in chemistry open a new world of research, new and surprising materials never before found in nature can now be synthesized and, as a wonderful result, observed a series of physical phenomena never before imagined. Among these are many new materials the molecular magnets, the subject of this book and magnetic properties that are often reflections of the quantum behavior of these materials. Aside from the wonderful experience of exploring something new, the theoretical models that describe the behavior these magnetic materials are, in most cases, soluble analytically, which allows us to know in detail the physical mechanisms governing these materials. Still, the academic interest in parallel this subject, these materials have a number of properties that are promising to be used in technological devices, such as in computers quantum magnetic recording, magnetocaloric effect, spintronics and many other devices. This volume will journey through the world of molecular magnets, from the structural description of these materials to state of the art research.

  6. Evolução da Biologia Molecular nos Síndromes Mieloproliferativos Crónicos e aplicação do seu diagnóstico na actualidade

    OpenAIRE

    Rua, Catarina; Santos, Tânia; Ramirez, Elisa; Olabarría, Maria Victoria; Herrera, Mónica; Jaleco, Ana

    2012-01-01

    O termo Síndrome Mieloproliferativo Crónico descreve um grupo de patologias (neoplasias hematológicas) que têm como característica comum a proliferação descontrolada (clonal) de um ou mais componentes hematopoiéticos da medula óssea e, em muitos casos, do baço e do fígado. Dentro dos Síndromes Mieloproliferativos Crónicos (SMC) os mais comuns são: Policitémia Vera (PV); Leucemia Mielóide Crónica (LMC); Mielofibrose; Trombocitemia Essencial (TE). Este trabalho centrou-se na PV e LMC. ...

  7. Evolução da Biologia Molecular nos Síndromes Mieloproliferativos Crónicos e Aplicação do seu diagnóstico na actualidade

    OpenAIRE

    Rua, Catarina de Aguiar S. R.; Santos, Tânia; Ramirez, Elisa; Olabarría, Maria Victória de; Herrera, Mónica

    2011-01-01

    O termo Síndrome Mieloproliferativo Crónico descreve um grupo de patologias (neoplasias hematológicas) que têm como característica comum a proliferação descontrolada (clonal) de um ou mais componentes hematopoiéticos da medula óssea e, em muitos casos, do baço e do fígado. Dentro dos Síndromes Mieloproliferativos Crónicos (SMC) os mais comuns são: Policitémia Vera (PV); Leucemia Mielóide Crónica (LMC); Mielofibrose; Trombocitemia Essencial (TE). Este trabalho centrou-se na PV e LMC. ...

  8. Molecular hematology

    National Research Council Canada - National Science Library

    Provan, Drew; Gribben, John

    2010-01-01

    ... The molecular basis of hemophilia, 219 Paul LF Giangrande 4 The genetics of acute myeloid leukemias, 42 Carolyn J Owen & Jude Fitzgibbon 19 The molecular basis of von Willebrand disease, 233 Luciano Baronc...

  9. Na/K Pump and Beyond: Na/K-ATPase as a Modulator of Apoptosis and Autophagy.

    Science.gov (United States)

    Felippe Gonçalves-de-Albuquerque, Cassiano; Ribeiro Silva, Adriana; Ignácio da Silva, Camila; Caire Castro-Faria-Neto, Hugo; Burth, Patrícia

    2017-04-21

    Lung cancer is a leading cause of global cancer deaths. Na/K-ATPase has been studied as a target for cancer treatment. Cardiotonic steroids (CS) trigger intracellular signalling upon binding to Na/K-ATPase. Normal lung and tumour cells frequently express different pump isoforms. Thus, Na/K-ATPase is a powerful target for lung cancer treatment. Drugs targeting Na/K-ATPase may induce apoptosis and autophagy in transformed cells. We argue that Na/K-ATPase has a role as a potential target in chemotherapy in lung cancer treatment. We discuss the effects of Na/K-ATPase ligands and molecular pathways inducing deleterious effects on lung cancer cells, especially those leading to apoptosis and autophagy.

  10. Na/K Pump and Beyond: Na/K-ATPase as a Modulator of Apoptosis and Autophagy

    Directory of Open Access Journals (Sweden)

    Cassiano Felippe Gonçalves-de-Albuquerque

    2017-04-01

    Full Text Available Lung cancer is a leading cause of global cancer deaths. Na/K-ATPase has been studied as a target for cancer treatment. Cardiotonic steroids (CS trigger intracellular signalling upon binding to Na/K-ATPase. Normal lung and tumour cells frequently express different pump isoforms. Thus, Na/K-ATPase is a powerful target for lung cancer treatment. Drugs targeting Na/K-ATPase may induce apoptosis and autophagy in transformed cells. We argue that Na/K-ATPase has a role as a potential target in chemotherapy in lung cancer treatment. We discuss the effects of Na/K-ATPase ligands and molecular pathways inducing deleterious effects on lung cancer cells, especially those leading to apoptosis and autophagy.

  11. The thermodynamic characteristics of vaporization in the NaI-PrI3 system

    Science.gov (United States)

    Motalov, V. B.; Kudin, L. S.; Markus, T.

    2009-05-01

    The vaporization of the NaI-PrI3 quasi-binary system was studied by high-temperature mass spectrometry over the whole concentration range. At 623-994 K, saturated vapor contained not only (NaI) n and (PrI3) n molecules ( n = 1, 2) and Na+(NaI) n ( n = 0-4) and I-(PrI3) n ( n = 1-2) ions but also mixed molecular and ionic associates recorded for the first time (NaPrI4, Na2PrI5, NaPrI{3/+}, Na2PrI{4/+}, Na3PrI{5/+}, Na4PrI{6/+}, NaPrI{5/-}, and NaPr2I{8/-}). The partial vapor pressures of molecules were calculated, and the equilibrium constants of the dissociation of neutral and charged associates were measured. The enthalpies of molecular and ion-molecular reactions were determined, and the enthalpies of formation of gaseous molecules and ions were obtained.

  12. Application of the generator coordinates method to the intra-molecular proton tunneling in the malonaldehyde molecule; Aplicacao do metodo das coordenadas geradoras ao processo de tunelamento do proton intramolecular na molecula de malonaldeido

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Andre Campos Kersten

    1995-12-31

    The effects of different vibrational modes on the isomerization process of polyatomic molecules, or solvent`s effects on reaction rates are object of up-to-date interest. In general, such many body phenomena are, in principle, multidimensional, and they first require a reduction of relevant degrees of freedom. In order to investigated, some aspects of the intra-molecular proton tunneling on a malonaldehyde molecule, we use the Generator Coordinate Method. The model used to describe such a process is the so-called System-Bath model, where the system is the reaction coordinate and the bath are the intrinsic degrees of freedom (vibrational modes of the molecule), which are described by a harmonic oscillator set linearly coupled to the system. The reduction of the multidimensional problem to the effective unidimensional one is done using a energy related variational principle on the intrinsic degrees of freedom. we obtained analytically a effective Hamiltonian where the effects of the various degrees of freedom reveal themselves in the appearance of a effective mass and in changes of the shape of the potential barrier. The analyticity of the method was crucial on identifying clearly the roles played by the different physical parameters involved. (author) 17 refs., 29 figs.

  13. B2O3/SiO2 substitution effect on structure and properties of Na2O-CaO-SrO-P2O5-SiO2 bioactive glasses from molecular dynamics simulations.

    Science.gov (United States)

    Ren, Mengguo; Lu, Xiaonan; Deng, Lu; Kuo, Po-Hsuen; Du, Jincheng

    2018-05-23

    The effect of B2O3/SiO2 substitution in SrO-containing 55S4.3 bioactive glasses on glass structure and properties, such as ionic diffusion and glass transition temperature, was investigated by combining experiments and molecular dynamics simulations with newly developed potentials. Both short-range (such as bond length and bond angle) and medium-range (such as polyhedral connection and ring size distribution) structures were determined as a function of glass composition. The simulation results were used to explain the experimental results for glass properties such as glass transition temperature and bioactivity. The fraction of bridging oxygen increased linearly with increasing B2O3 content, resulting in an increase in overall glass network connectivity. Ion diffusion behavior was found to be sensitive to changes in glass composition and the trend of the change with the level of substitution is also temperature dependent. The differential scanning calorimetry (DSC) results show a decrease in glass transition temperature (Tg) with increasing B2O3 content. This is explained by the increase in ion diffusion coefficient and decrease in ion diffusion energy barrier in glass melts, as suggested by high-temperature range (above Tg) ion diffusion calculations as B2O3/SiO2 substitution increases. In the low-temperature range (below Tg), the Ea for modifier ions increased with B2O3/SiO2 substitution, which can be explained by the increase in glass network connectivity. Vibrational density of states (VDOS) were calculated and show spectral feature changes as a result of the substitution. The change in bioactivity with B2O3/SiO2 substitution is discussed with the change in pH value and release of boric acid into the solution.

  14. At NA2

    CERN Multimedia

    1977-01-01

    One of the NA2 calorimeter sections is moved in. The NA2 calorimeter was divided in two halves, to the left and the right of the beam, each half consisting of sheets of passive high Z material interleaved with blades of plastic scintillators. The photo shows on the right, the upstream 'electron' module with eleven lead plates for a total radiation length of 20.

  15. Clues to NaCN formation

    Science.gov (United States)

    Quintana-Lacaci, G.; Cernicharo, J.; Velilla Prieto, L.; Agúndez, M.; Castro-Carrizo, A.; Fonfría, J. P.; Massalkhi, S.; Pardo, J. R.

    2017-11-01

    Context. ALMA is providing us essential information on where certain molecules form. Observing where these molecules emission arises from, the physical conditions of the gas, and how this relates with the presence of other species allows us to understand the formation of many species, and to significantly improve our knowledge of the chemistry that occurs in the space. Aims: We studied the molecular distribution of NaCN around IRC +10216, a molecule detected previously, but whose origin is not clear. High angular resolution maps allow us to model the abundance distribution of this molecule and check suggested formation paths. Methods: We modeled the emission of NaCN assuming local thermal equilibrium (LTE) conditions. These profiles were fitted to azimuthal averaged intensity profiles to obtain an abundance distribution of NaCN. Results: We found that the presence of NaCN seems compatible with the presence of CN, probably as a result of the photodissociation of HCN, in the inner layers of the ejecta of IRC +10216. However, similar as for CH3CN, current photochemical models fail to reproduce this CN reservoir. We also found that the abundance peak of NaCN appears at a radius of 3 × 1015 cm, approximately where the abundance of NaCl, suggested to be the parent species, starts to decay. However, the abundance ratio shows that the NaCl abundance is lower than that obtained for NaCN. We expect that the LTE assumption might result in NaCN abundances higher than the real ones. Updated photochemical models, collisional rates, and reaction rates are essential to determine the possible paths of the NaCN formation. Based on observations carried out with ALMA and the IRAM 30 m Telescope. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada) and NSC and ASIAA (Taiwan), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. IRAM is supported by INSU/CNRS (France

  16. Infecção por Hepatozoon canis em canino doméstico na região Sul do Brasil confirmada por técnicas moleculares Hepatozoon canis infection in a domestic dog in Southern Brazil confirmed by molecular techniques

    Directory of Open Access Journals (Sweden)

    Camila Serina Lasta

    2009-10-01

    Full Text Available Hepatozoonose canina é uma doença transmitida por carrapatos e causada pelo protozoário Hepatozoon spp. No Brasil, existem poucos relatos da infecção e dados sobre sua epidemiologia, patogenicidade, seus vetores e sua caracterização genética. No presente estudo, são utilizadas técnicas moleculares para o diagnóstico e a caracterização do parasita. Foi estudado um canino que apresentava emagrecimento progressivo, anemia regenerativa, neutropenia e hiperglobulinemia. Gamontes de Hepatozoon spp. foram visualizados no esfregaço sanguíneo. DNA foi extraído do sangue, e o diagnóstico foi confirmado pela técnica da reação em cadeia da polimerase (PCR. O produto da PCR foi purificado a partir do gel e clonado, e o fragmento de 625pb foi sequenciado. A sequência foi submetida ao GenBank como isolado de Porto Alegre, e a análise molecular revelou homologia de 98-100% com Hepatozoon canis e máxima de 92% com Hepatozoon americanum. Este estudo representa a primeira confirmação molecular da presença de H. canis no sul do Brasil.Canine Hepatozoonosis is a vector-borne disease caused by the protozoa Hepatozoon spp. There are few case reports in Brazil and the epidemiology, pathogenicity, vectors and molecular characterization is poorly understood. The present study used a canine presenting weight loss, regenerative anemia, neutropenia and hyperglobulinemia. Hepatozoon spp. gamonts were observed in the blood smear by microscopy. DNA was extracted from blood, and the diagnosis was confirmed by PCR assay. The PCR product was purified from gel and cloned. A fragment of 625bp was sequenced and submitted to the GenBank database as Isolate Porto Alegre. Molecular analysis showed a homology of 98-100% with Hepatozoon canis and less than 92% for H. americanum. This study represents the first molecular confirmation that H. canis is present in Southern Brazil.

  17. Polarization dependence of Na* + Na* associative ionization revisited

    NARCIS (Netherlands)

    Meijer, H.A.J.; Meulen, H.P. v.d.; Morgenstern, R.; Hertel, I.V.; Meyer, E.; Witte, R.

    1986-01-01

    The dependence of the associative ionization process Na 3 2P3/2 + Na 3 2P3/2 → Na2+ + e- on the polarization of the laser light used for Na excitation was independently investigated in Utrecht and Berlin. The purpose of this paper is to clarify discrepancies between two other earlier experimental

  18. Molecular Diagnostics

    OpenAIRE

    Choe, Hyonmin; Deirmengian, Carl A.; Hickok, Noreen J.; Morrison, Tiffany N.; Tuan, Rocky S.

    2015-01-01

    Orthopaedic infections are complex conditions that require immediate diagnosis and accurate identification of the causative organisms to facilitate appropriate management. Conventional methodologies for diagnosis of these infections sometimes lack accuracy or sufficient rapidity. Current molecular diagnostics are an emerging area of bench-to-bedside research in orthopaedic infections. Examples of promising molecular diagnostics include measurement of a specific biomarker in the synovial fluid...

  19. Molecular genetics

    International Nuclear Information System (INIS)

    Parkinson, D.R.; Krontiris, T.G.

    1986-01-01

    In this chapter the authors review new findings concerning the molecular genetics of malignant melanoma in the context of other information obtained from clinical, epidemiologic, and cytogenetic studies in this malignancy. These new molecular approaches promise to provide a more complete understanding of the mechanisms involved in the development of melanoma, thereby suggesting new methods for its treatment and prevention

  20. Molecular Modeling

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 5. Molecular Modeling: A Powerful Tool for Drug Design and Molecular Docking. Rama Rao Nadendla. General Article Volume 9 Issue 5 May 2004 pp 51-60. Fulltext. Click here to view fulltext PDF. Permanent link:

  1. Modeling the sorption dynamics of NaH using a reactive force field

    International Nuclear Information System (INIS)

    Ojwang, J. G. O.; Santen, Rutger van; Kramer, Gert Jan; Duin, Adri C. T. van; Goddard, William A. III

    2008-01-01

    We have parametrized a reactive force field for NaH, ReaxFF NaH , against a training set of ab initio derived data. To ascertain that ReaxFF NaH is properly parametrized, a comparison between ab initio heats of formation of small representative NaH clusters with ReaxFF NaH was done. The results and trend of ReaxFF NaH are found to be consistent with ab initio values. Further validation includes comparing the equations of state of condensed phases of Na and NaH as calculated from ab initio and ReaxFF NaH . There is a good match between the two results, showing that ReaxFF NaH is correctly parametrized by the ab initio training set. ReaxFF NaH has been used to study the dynamics of hydrogen desorption in NaH particles. We find that ReaxFF NaH properly describes the surface molecular hydrogen charge transfer during the abstraction process. Results on heat of desorption versus cluster size shows that there is a strong dependence on the heat of desorption on the particle size, which implies that nanostructuring enhances desorption process. To gain more insight into the structural transformations of NaH during thermal decomposition, we performed a heating run in a molecular dynamics simulation. These runs exhibit a series of drops in potential energy, associated with cluster fragmentation and desorption of molecular hydrogen. This is consistent with experimental evidence that NaH dissociates at its melting point into smaller fragments

  2. Optical Pumping of Molecular Gases

    Science.gov (United States)

    1976-04-01

    ser emission ott a The typical experimental apparatus is shown i.- Fig. *series of green and yellow molecular B-X’-basnd transi- 2. For B-bantd optical...with A, at 0. 473 pim and that Na2 may operate as a flash -lamp -pumped laser X,... at 0. 54 umn the Doppler widths are AwD - 12.42 source with buffer

  3. Molecular geometry

    CERN Document Server

    Rodger, Alison

    1995-01-01

    Molecular Geometry discusses topics relevant to the arrangement of atoms. The book is comprised of seven chapters that tackle several areas of molecular geometry. Chapter 1 reviews the definition and determination of molecular geometry, while Chapter 2 discusses the unified view of stereochemistry and stereochemical changes. Chapter 3 covers the geometry of molecules of second row atoms, and Chapter 4 deals with the main group elements beyond the second row. The book also talks about the complexes of transition metals and f-block elements, and then covers the organometallic compounds and trans

  4. Characterisation of Zygosaccharomyces rouxii Na+/H+ antiporters

    Czech Academy of Sciences Publication Activity Database

    Přibylová, Lenka; Papoušková, Klára; Sychrová, Hana; de Montigny, J.

    2007-01-01

    Roč. 274, Suppl.1 (2007), s. 127-127 ISSN 1742-464X. [FEBS Congress Molecular Machines /32./. 07.07.2007-12.07.2007, Vienna] R&D Projects: GA ČR(CZ) GA204/05/0028 Institutional research plan: CEZ:AV0Z50110509 Keywords : cpo1 * Zygosaccharomyces rouxii * Na+/H+ antiporters * salt tolerance Subject RIV: EB - Genetics ; Molecular Biology

  5. Mechanism of μ-conotoxin PIIIA binding to the voltage-gated Na+ channel NaV1.4.

    Directory of Open Access Journals (Sweden)

    Rong Chen

    Full Text Available Several subtypes of voltage-gated Na+ (NaV channels are important targets for pain management. μ-Conotoxins isolated from venoms of cone snails are potent and specific blockers of different NaV channel isoforms. The inhibitory effect of μ-conotoxins on NaV channels has been examined extensively, but the mechanism of toxin specificity has not been understood in detail. Here the known structure of μ-conotoxin PIIIA and a model of the skeletal muscle channel NaV1.4 are used to elucidate elements that contribute to the structural basis of μ-conotoxin binding and specificity. The model of NaV1.4 is constructed based on the crystal structure of the bacterial NaV channel, NaVAb. Six different binding modes, in which the side chain of each of the basic residues carried by the toxin protrudes into the selectivity filter of NaV1.4, are examined in atomic detail using molecular dynamics simulations with explicit solvent. The dissociation constants (Kd computed for two selected binding modes in which Lys9 or Arg14 from the toxin protrudes into the filter of the channel are within 2 fold; both values in close proximity to those determined from dose response data for the block of NaV currents. To explore the mechanism of PIIIA specificity, a double mutant of NaV1.4 mimicking NaV channels resistant to μ-conotoxins and tetrodotoxin is constructed and the binding of PIIIA to this mutant channel examined. The double mutation causes the affinity of PIIIA to reduce by two orders of magnitude.

  6. Molecular Electronics

    DEFF Research Database (Denmark)

    Jennum, Karsten Stein

    This thesis includes the synthesis and characterisation of organic compounds designed for molecular electronics. The synthesised organic molecules are mainly based on two motifs, the obigo(phenyleneethynylenes) (OPE)s and tetrathiafulvalene (TTF) as shown below. These two scaffolds (OPE and TTF......) are chemically merged together to form cruciform-like structures that are an essential part of the thesis. The cruciform molecules were subjected to molecular conductance measurements to explore their capability towards single-crystal field-effect transistors (Part 1), molecular wires, and single electron......, however, was obtained by a study of a single molecular transistor. The investigated OPE5-TTF compound was captured in a three-terminal experiment, whereby manipulation of the molecule’s electronic spin was possible in different charge states. Thus, we demonstrated how the cruciform molecules could...

  7. Molecular sciences

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    The research in molecular sciences summarized includes photochemistry, radiation chemistry, geophysics, electromechanics, heavy-element oxidizers , heavy element chemistry collisions, atoms, organic solids. A list of publications is included

  8. NAKUPOVANJE NA SPLETU

    OpenAIRE

    Visenjak, Monika

    2013-01-01

    Nakupovanje na spletu je prihodnost poslovanja. Za podjetja pomeni manjše stroške, lažje prilagajanje tržnim pogojem. Hitreje lahko razvijajo odnose in analizirajo uporabnike, saj jim je dan dostop o nakupnih podatkih uporabnika. Za potrošnike je nakupovanje na spletu možnost hitrega, preprostega in učinkovitega nakupovanja od doma ali pisarne. Pomembno je, da se seznanijo z vsemi informacijami in pogoji spletnih trgovin, saj se lahko le tako izognejo nezadovoljstvu ob nakupu v spletni trgovi...

  9. Otimização do tamanho de população sob acasalamento seletivo na seleção assistida por marcadores moleculares Optimization of the population size under selective mating in the selection assisted by molecular markers

    Directory of Open Access Journals (Sweden)

    Marcelo Jangarelli

    2010-12-01

    Full Text Available Foram simulados diferentes tamanhos populacionais para estimar os valores fenotípicos na seleção assistida por marcadores para características quantitativas com valores de herdabilidade de 0,10; 0,40 e 0,70. Procedeu-se à análise de agrupamento com os desempenhos fenotípicos, cuja finalidade foi obter estruturas de classificação entre as amostras visando à otimização na detecção de QTL. O sistema de simulação genética (Genesys foi utilizado para a simulação de três genomas (cada qual com uma única característica cuja distinção estava no valor da herdabilidade e das populações base e inicial. Cada população inicial foi submetida à seleção assistida por marcadores por 20 gerações consecutivas, em que os genitores selecionados acasalavam-se seletivamente, entre os melhores e os piores. Essa estratégia seletiva de acasalamento mostrou-se eficiente na redução do número de indivíduos requeridos em uma população para mapeamento de QTL. À medida que aumenta a magnitude da herdabilidade, menores tamanhos populacionais são exigidos para manter similaridades nos incrementos fenotípicos. O emprego de amostras com 300, 250 e 200 ou mais indivíduos para as herdabilidades de 0,10; 0,40 e 0,70, respectivamente, é desnecessário, tendo em vista as inferências equivalentes indicadas pelos métodos de otimização de Tocher e da ligação completa, oriundas do sistema de análises estatísticas e genéticas (SAEG.Different population sizes were simulated to estimate the phenotypic values in the selection assisted by markers for quantitative characteristics with heritability values of 0.10, 0.40 and 0.70. Cluster analysis with the phenotypic performance was carried out aiming at obtaining classification structure among the samples to optimize QTL detection. The genetic simulation system (Genesys was used for the simulation of three genomes (each one consisting of a single characteristic whose distinction was the value

  10. Riso na epilepsia

    Directory of Open Access Journals (Sweden)

    Edymar Jardim

    1967-06-01

    Full Text Available São estudados três casos de síndrome convulsiva temporal, com manifestações concomitantes de riso na sua fase inicial. As características principais foram a imotivação e á incoercibilidade do riso. Esses sintomas desapareceram com o uso de anticonvulsivantes.

  11. Molecular fountain.

    Energy Technology Data Exchange (ETDEWEB)

    Strecker, Kevin E.; Chandler, David W.

    2009-09-01

    A molecular fountain directs slowly moving molecules against gravity to further slow them to translational energies that they can be trapped and studied. If the molecules are initially slow enough they will return some time later to the position from which they were launched. Because this round trip time can be on the order of a second a single molecule can be observed for times sufficient to perform Hz level spectroscopy. The goal of this LDRD proposal was to construct a novel Molecular Fountain apparatus capable of producing dilute samples of molecules at near zero temperatures in well-defined user-selectable, quantum states. The slowly moving molecules used in this research are produced by the previously developed Kinematic Cooling technique, which uses a crossed atomic and molecular beam apparatus to generate single rotational level molecular samples moving slowly in the laboratory reference frame. The Kinematic Cooling technique produces cold molecules from a supersonic molecular beam via single collisions with a supersonic atomic beam. A single collision of an atom with a molecule occurring at the correct energy and relative velocity can cause a small fraction of the molecules to move very slowly vertically against gravity in the laboratory. These slowly moving molecules are captured by an electrostatic hexapole guiding field that both orients and focuses the molecules. The molecules are focused into the ionization region of a time-of-flight mass spectrometer and are ionized by laser radiation. The new molecular fountain apparatus was built utilizing a new design for molecular beam apparatus that has allowed us to miniaturize the apparatus. This new design minimizes the volumes and surface area of the machine allowing smaller pumps to maintain the necessary background pressures needed for these experiments.

  12. Rotational dynamics of propylene inside Na-Y zeolite cages

    Indian Academy of Sciences (India)

    We report here the quasielastic neutron scattering (QENS) studies on the dynamics of propylene inside Na-Y zeolite using triple axis spectrometer (TAS) at Dhruva reactor, Trombay. Molecular dynamics (MD) simulations performed on the system had shown that the rotational motion involves energy larger than that involved ...

  13. Identidade molecular dos fitoplasmas associados aos enfezamentos do tomateiro e da berinjela com base na análise do gene 16S rDNA Molecular identity of the phytoplasma associated to stunting of tomato and eggplant on the basis of analyses of the 16S rDNA

    Directory of Open Access Journals (Sweden)

    Ana Paula de Oliveira Amaral Mello

    2007-09-01

    Full Text Available Doenças de hortaliças de ocorrência no território brasileiro e em outras áreas do mundo têm sido associadas a diversos fitoplasmas. Na região de Piracicaba-SP e Bragança Paulista-SP, em plantas de tomate e berinjela foram observados sintomas típicos de enfezamento caracterizados por porte reduzido, clorose foliar, superbrotamento de ramos, desenvolvimento anormal do cálice, encurtamento de entre-nós, redução no tamanho de folhas, flores e frutos. Através de duplo PCR, utilizando os iniciadores R16 mF1/mR2 e R16 F2n/R2, fragmentos de DNA de 1,2 kb foram amplificados de amostras sintomáticas, demonstrando a presença de fitoplasma nos tecidos das plantas. O uso de iniciadores específicos demonstrou que estes fitoplasmas eram afiliados ao grupo 16SrIII. Análises de RFLP, usando as enzimas de restrição AluI, HpaII, KpnI, MboI, MseI e RsaI confirmaram que os fitoplasmas detectados eram representantes do grupo 16SrIII. Os fragmentos de DNA amplificados foram clonados em Escherichia coli, sequenciados e comparados, por homologia de seqüência, entre si e com outros fitoplasmas do grupo 16SrIII. Um índice de similaridade de seqüência acima de 95% foi encontrado quando seqüências dos fitoplasmas detectados em tomate e berinjela foram comparadas com aquelas de outros representantes do grupo 16SrIII. Um índice de 98-99% foi obtido quando seqüências dos fitoplasmas encontrados em tomate e berinjela foram comparadas entre si. Estes resultados evidenciaram que o enfezamento do tomateiro e da berinjela podem estar associados a um mesmo fitoplasma, com base na análise de seqüências do gene do 16S rDNA.Vegetable diseases occurring in the Brazilian territory and around the world have been associated with various phytoplasmas. In the region of Piracicaba-SP and Bragança-SP, in eggplant and tomato plants typical symptoms of stunting characterized by reduced canopy, leaf yellowing, proliferation of shoots, calix malformation

  14. RAPD-PCR na identificação molecular de plantas medicinais regulamentadas pelo Sistema Único de Saúde do Brasil | RAPD-PCR in molecular identification of medicinal plants regulated by the Unified Health System in Brazil

    Directory of Open Access Journals (Sweden)

    José Luiz Neves Aguiar

    2015-08-01

    Full Text Available O desenvolvimento de metodologia altamente discriminatória para a identificação e caracterização de genótipos das espécies de plantas medicinais regulamentadas pelo sistema público de saúde brasileiro (SUS é de suma importância para o controle de qualidade destas espécies como matérias-primas na produção de medicamentos fitoterápicos, consequentemente, minimizar o risco sanitário associado à ineficácia terapêutica devido ao uso de matéria prima de identidade duvidosa. Por isto, foi utilizado o método RAPD-PCR para a elaboração de um perfil genético de três espécies de plantas medicinais regulamentadas pelo SUS do Brasil: Mikania glomerata, Maytenus ilicifolia e Schinus terebinthifolius, a partir de exemplares destas plantas, que foram cedidas pela Coleção Temática de Plantas Medicinais do Instituto de Pesquisas do Jardim Botânico do Rio de Janeiro. Os 60 iniciadores utilizados no RAPD-PCR com o DNA das três espécies geraram 1284 produtos amplificados que variaram de 100-1500 pb. Foram selecionados cinco iniciadores que geraram no total 76 fragmentos entre 200-1100 pb com astrês espécies, sendo os iniciadores OPG18, OPA7 e OPG17 para a Mikania glomerata, os iniciadores OPG20, OPC13 e OPA11 para a Maytenus ilicifolia e OPA4, OPA18 e OPG14 para a Schinus terebinthifolius e os iniciadores OPA17 e OPC6 para as três espécies. Os perfis resultantes permitiram a identificação eficiente das espécies. Foram identificados iniciadores que geraram um único fragmento que poderão servir para desenhar um iniciador específico, que poderá ser usado na identificação da planta em produtos como monofarmacos e associações. ----------------------------------------------------------------------------------------------- Development of a highly discriminatory method for the identification of genotypes and species of medicinal plants regulated by the Brazilian public health system (SUS is of paramount importance for the

  15. Molecular docking.

    Science.gov (United States)

    Morris, Garrett M; Lim-Wilby, Marguerita

    2008-01-01

    Molecular docking is a key tool in structural molecular biology and computer-assisted drug design. The goal of ligand-protein docking is to predict the predominant binding mode(s) of a ligand with a protein of known three-dimensional structure. Successful docking methods search high-dimensional spaces effectively and use a scoring function that correctly ranks candidate dockings. Docking can be used to perform virtual screening on large libraries of compounds, rank the results, and propose structural hypotheses of how the ligands inhibit the target, which is invaluable in lead optimization. The setting up of the input structures for the docking is just as important as the docking itself, and analyzing the results of stochastic search methods can sometimes be unclear. This chapter discusses the background and theory of molecular docking software, and covers the usage of some of the most-cited docking software.

  16. Molecular modeling

    Directory of Open Access Journals (Sweden)

    Aarti Sharma

    2009-01-01

    Full Text Available The use of computational chemistry in the development of novel pharmaceuticals is becoming an increasingly important tool. In the past, drugs were simply screened for effectiveness. The recent advances in computing power and the exponential growth of the knowledge of protein structures have made it possible for organic compounds to be tailored to decrease the harmful side effects and increase the potency. This article provides a detailed description of the techniques employed in molecular modeling. Molecular modeling is a rapidly developing discipline, and has been supported by the dramatic improvements in computer hardware and software in recent years.

  17. Estudo experimental dos efeitos da heparina de baixo peso molecular (Enoxaparina na formação de calo ósseo em fêmures de ratos The effects of low-molecular-weight heparin (Enoxaparin on bony callus formation in rats' femurs - an experimental study

    Directory of Open Access Journals (Sweden)

    Salim Mussi Filho

    2006-01-01

    Full Text Available O tromboembolismo venoso é uma complicação grave que pode ocorrer após fraturas. O tratamento anticoagulante mais utilizado é com a heparina de baixo peso molecular (HBPM. Existem estudos que mostram que essa droga pode interferir no metabolismo ósseo. Com o objetivo de avaliar a influência da HBPM no processo de formação de calo ósseo, realizamos um estudo experimental em ratos. A amostra constituiu-se de 22 ratos de linhagem Wistar, machos, que foram submetidos à fratura diafisária de seus fêmures direitos. Foram divididos em dois grupos de 11. No grupo controle, os animais recebiam soro fisiológico e no grupo de estudo, recebiam HBPM, enoxaparina, diariamente, por 28 dias. Após este período os ratos foram submetidos à eutanásia e os fêmures foram avaliados. No estudo macroscópico foi constatada consolidação em 11 animais (100% que não receberam enoxaparina, e, em dez animais (90,9% que receberam a droga em estudo. No estudo histológico foi constatada a formação de calo ósseo em todos os fêmures. Concluiu-se neste experimento que a enoxaparina não altera o processo de consolidação óssea em fêmures de ratos Wistar.Venous thromboembolism is a serious complication that may follow fractures. The most commonly used anticoagulant treatment is low-molecular-weight heparin (LMWH. There are some studies showing that this drug may interfere on bone metabolism. With the objective of evaluating the LMWH influence on the process of bony callus formation, we conducted an experimental study on rats. Sample was constituted of 22 Wistar male rats, which were submitted to diaphyseal fracture on their right femurs. They were divided into two groups of 11 subjects each. In the control group, the animals received saline solution and in the study group, they received LMWH - enoxaparin - in a daily basis, during 28 days. After that period, the rats were submitted to euthanasia for femur assessment purposes. At the macroscopic study

  18. Distinct interactions of Na+ and Ca2+ ions with the selectivity filter of the bacterial sodium channel NaVAb

    International Nuclear Information System (INIS)

    Ke, Song; Zangerl, Eva-Maria; Stary-Weinzinger, Anna

    2013-01-01

    Highlights: ► Ca 2+ translocates slowly in the filter, due to lack of “loose” knock-on mechanism. ► Identification of a high affinity binding site in Na V Ab selectivity filter. ► Changes of EEEE locus triggered by electrostatic interactions with Ca 2+ ions. -- Abstract: Rapid and selective ion transport is essential for the generation and regulation of electrical signaling pathways in living organisms. In this study, we use molecular dynamics simulations and free energy calculations to investigate how the bacterial sodium channel Na V Ab (Arcobacter butzleri) differentiates between Na + and Ca 2+ ions. Multiple nanosecond molecular dynamics simulations revealed distinct binding patterns for these two cations in the selectivity filter and suggested a high affinity calcium binding site formed by backbone atoms of residues Leu-176 and Thr-175 (S CEN ) in the sodium channel selectivity filter

  19. Inorganic-Organic Coating via Molecular Layer Deposition Enables Long Life Sodium Metal Anode.

    Science.gov (United States)

    Zhao, Yang; Goncharova, Lyudmila V; Zhang, Qian; Kaghazchi, Payam; Sun, Qian; Lushington, Andrew; Wang, Biqiong; Li, Ruying; Sun, Xueliang

    2017-09-13

    Metallic Na anode is considered as a promising alternative candidate for Na ion batteries (NIBs) and Na metal batteries (NMBs) due to its high specific capacity, and low potential. However, the unstable solid electrolyte interphase layer caused by serious corrosion and reaction in electrolyte will lead to big challenges, including dendrite growth, low Coulombic efficiency and even safety issues. In this paper, we first demonstrate the inorganic-organic coating via advanced molecular layer deposition (alucone) as a protective layer for metallic Na anode. By protecting Na anode with controllable alucone layer, the dendrites and mossy Na formation have been effectively suppressed and the lifetime has been significantly improved. Moreover, the molecular layer deposition alucone coating shows better performances than the atomic layer deposition Al 2 O 3 coating. The novel design of molecular layer deposition protected Na metal anode may bring in new opportunities to the realization of the next-generation high energy-density NIBs and NMBs.

  20. Study of the glass forming ability of Cu{sub 60}Zr{sub 32,5}Ti{sub 7,5} alloy by molecular dynamics; Formacao de fase amorfa na liga Cu{sub 60}Zr{sub 32,5}Ti{sub 7,5} por dinamica molecular

    Energy Technology Data Exchange (ETDEWEB)

    Schimidt, C.S.; Lima, L.V.; Bastos, I.N.; Aliaga, L.C.R., E-mail: camilaschimidt17@gmail.com [Universidade do Estado do Rio de Janeiro (UERJ), Nova Friburgo, RJ (Brazil). Departamento de Materiais

    2016-07-01

    This article presents the results of molecular dynamics simulation of Cu{sub 60}Zr{sub 32.5}Ti{sub 7.5} alloy through the open source code LAMMPS. Amorphous samples were produced by quenching the metallic molten from 2300K to 200K at cooling rates of 50, 5 and 0.5K/ps. The pair distribution functions of both the liquid and solid were calculated and compared at different temperatures. The topology of short-range order was analyzed using the Voronoi tessellation method, which determined the presence of Cu-centered icosahedral clusters as the prevailing in the amorphous state at 300K. Moreover, the sample was submitted to uniaxial tensile tests at strain rate of 10ps{sup -1}, in order to investigate the mechanical behavior of the metallic glass. The result of the stress-strain curve showed that applied loads lead to the plastic regime. However, the presences of shear bands, typical in the experimental testing, were not observed. Moreover, the evolution of the viscosity above the glass transition temperature and the fragility of the alloy were determined. The solidus and liquidus temperatures were determined and a good agreement with experimental data was found. (author)

  1. Atletismo na escola : realidade?

    OpenAIRE

    Sampaio, Alessandro Oliveira de

    2012-01-01

    O correr, saltar, lançar e arremessar são elementos básicos do atletismo, sendo fundamentais para o ser humano, devido ao favorecimento do desenvolvimento físico e motor. Sendo um dos conteúdos principais do desporto e da educação física escolar, foi realizado um estudo relacionado à prática do atletismo na escola, na qual o objetivo desta pesquisa foi verificar se entre os professores de educação física da rede pública de ensino fundamental de 5ª a 8ª séries, da cidade satélite de Samambaia ...

  2. Molecular spectroscopy

    International Nuclear Information System (INIS)

    Kokh, Eh.; Zonntag, B.

    1981-01-01

    The latest investigation results on molecular spectroscopy with application of synchrotron radiation in the region of vacuum ultraviolet are generalized. Some results on investigation of excited, superexcited and ionized molecule states with the use of adsorption spectroscopy, photoelectron spectroscopy, by fluorescent and mass-spectrometric methods are considered [ru

  3. Molecular Foundry

    Science.gov (United States)

    . New Study Indicates Greater Capacity for Carbon Storage in the Earth's Subsurface A team of Foundry minerals which make up the dominant clays in the Earth's deep subsurface. Doubling Down on Energy Storage identify molecular components within small volumes of biological samples, such as blood or urine. Industry

  4. Molecular farming

    NARCIS (Netherlands)

    Merck, K.B.; Vereijken, J.M.

    2006-01-01

    Molecular Farming is a new and emerging technology that promises relatively cheap and flexible production of large quantities of pharmaceuticals in genetically modified plants. Many stakeholders are involved in the production of pharmaceuticals in plants, which complicates the discussion on the

  5. Molecular gastronomy

    Science.gov (United States)

    This, Hervé

    2005-01-01

    For centuries, cooks have been applying recipes without looking for the mechanisms of the culinary transformations. A scientific discipline that explores these changes from raw ingredients to eating the final dish, is developing into its own field, termed molecular gastronomy. Here, one of the founders of the discipline discusses its aims and importance.

  6. Molecular Star

    Indian Academy of Sciences (India)

    In molecular self-assembly, molecules put themselves together in a predefined way ... work has been already published in Chemistry- A European Jour- nal in the September ... prevalent in matter ranging from atoms to molecules to biomolecules; it is also ... erate chemical forces are reversible and dynamic in nature mean-.

  7. Molecular ferromagnetism

    International Nuclear Information System (INIS)

    Epstein, A.J.

    1990-01-01

    This past year has been one of substantial advancement in both the physics and chemistry of molecular and polymeric ferromagnets. The specific heat studies of (DMeFc)(TCNE) have revealed a cusp at the three-dimensional ferromagnetic transition temperature with a crossover to primarily 1-D behavior at higher temperatures. This paper discusses these studies

  8. Preparing for NA4

    CERN Multimedia

    CERN PhotoLab

    1977-01-01

    Here, in one of the EF workshop, Albert Duchêne works on a pretty piece of mechanics. A few others await to be attended on the left. There are indications that the pipes were meant to house the carbon target (subdivided in eight sections) to be installed inside the toroid magnet of the NA4 experiment. The external strips were designed to possibly correct the magnetic field (???).

  9. Caracterização molecular de populações do nematóide-de-cisto-da-soja com diferentes índices de parasitismo na cultivar Hartwig Molecular characterization of soybean cyst nematode populations with different parasitism index to the Hartwig cultivar

    Directory of Open Access Journals (Sweden)

    Ricardo Vilela Abdelnoor

    2001-02-01

    Full Text Available Recentemente, foi descoberta uma raça do nematóide-de-cisto-da-soja (NCS; Heterodera glycines que apresentou a capacidade de quebrar a resistência da cultivar Hartwig, até então considerada resistente a todas as raças conhecidas do nematóide. Essa população foi coletada no Município de Sorriso, Estado do Mato Grosso, e foi caracterizada como raça 4. Para verificar a diversidade genética entre esta e outras populações pertencentes às raças 4 e 9, foi feita uma caracterização molecular pela técnica de marcadores moleculares RAPD. Foram utilizadas nove populações do NCS, das quais quatro apresentavam a capacidade de parasitar 'Hartwig'. Foi verificado que as populações capazes de parasitar 'Hartwig' foram bastante diferentes das demais. Por meio de análise de agrupamento, com base nas distâncias genéticas encontradas, foram obtidos três grupos: o primeiro, constituído por indivíduos classificados como raça 4, mas que não parasitam 'Hartwig'; o segundo, constituído por quatro populações capazes de parasitar 'Hartwig', e o terceiro, por apenas uma população, classificado como raça 9, e que também não parasita 'Hartwig'. Este estudo confirmou que a população de NCS, encontrada em Sorriso, é geneticamente distinta das demais populações da raça 4 encontradas e constitui uma nova raça, denominada 4+.Recently, a new race of soybean cyst nematode (SCN (Heterodera glycines was discovered, which breaks the resistance of cultivar Hartwig, resistant to all known races of SCN. This population was obtained from soybean plants collected in the Sorriso county, state of Mato Grosso, Brazil, and is characterized as race 4. To verify if this isolate was different from others classified as races 4 and 9, their genetic diversity was analyzed by using the RAPD technique. Nine populations of SCN were analyzed, and only four populations were able to parasitize soybean plants cultivar Hartwig. Based on this study, it was

  10. The CERES / NA45 experiment

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    Ceres is one of the second generation heavy ion experiments at CERN's SPS. It is dedicated to the study of electron-positron pairs in relativistic nuclear collisions. NA45 is one of the seven experiments (NA44, NA45, NA49, NA50, NA52, WA97/NA57 and WA98) involved in CERN's Heavy Ion programme which provided evidence for the existence of a new state of matter, the quark-gluon plasma. In this state, quarks, instead of being bound up into more complex particles such as protons and neutrons, are liberated and roam freely. Theory predicts that this state must have existed at about 10 microseconds after the Big Bang, before the formation of matter as we know it today.

  11. Molecular Modelling

    Directory of Open Access Journals (Sweden)

    Aarti Sharma

    2009-12-01

    Full Text Available

    The use of computational chemistry in the development of novel pharmaceuticals is becoming an increasingly important
    tool. In the past, drugs were simply screened for effectiveness. The recent advances in computing power and
    the exponential growth of the knowledge of protein structures have made it possible for organic compounds to tailored to
    decrease harmful side effects and increase the potency. This article provides a detailed description of the techniques
    employed in molecular modeling. Molecular modelling is a rapidly developing discipline, and has been supported from
    the dramatic improvements in computer hardware and software in recent years.

  12. Molecular scale

    Directory of Open Access Journals (Sweden)

    Christopher H. Childers

    2016-03-01

    Full Text Available This manuscript demonstrates the molecular scale cure rate dependence of di-functional epoxide based thermoset polymers cured with amines. A series of cure heating ramp rates were used to determine the influence of ramp rate on the glass transition temperature (Tg and sub-Tg transitions and the average free volume hole size in these systems. The networks were comprised of 3,3′-diaminodiphenyl sulfone (33DDS and diglycidyl ether of bisphenol F (DGEBF and were cured at ramp rates ranging from 0.5 to 20 °C/min. Differential scanning calorimetry (DSC and NIR spectroscopy were used to explore the cure ramp rate dependence of the polymer network growth, whereas broadband dielectric spectroscopy (BDS and free volume hole size measurements were used to interrogate networks’ molecular level structural variations upon curing at variable heating ramp rates. It was found that although the Tg of the polymer matrices was similar, the NIR and DSC measurements revealed a strong correlation for how these networks grow in relation to the cure heating ramp rate. The free volume analysis and BDS results for the cured samples suggest differences in the molecular architecture of the matrix polymers due to cure heating rate dependence.

  13. Envolvimento pulmonar na polimiosite

    Directory of Open Access Journals (Sweden)

    Direndra Hasmucrai

    2010-07-01

    Full Text Available Resumo: Introdução: A polimiosite (PM e a dermatomiosite são classificadas como miopatias inflamatórias idiopáticas. O envolvimento pulmonar por PM é pouco frequente, estando descrito na literatura em cerca de 10% de casos.Os autores apresentam um caso de uma mulher de 75 anos, com queixas de febre, perda ponderal, artralgias, mialgias e diminuição simétrica e proximal da força muscular com impotência funcional dos membros superiores e inferiores, com início um mês antes do internamento. Apresentava infiltrados pulmonares na telerradiografia de tórax. Após estudo exaustivo estabeleceu-se o diagnóstico de envolvimento pulmonar na forma de pneumonia organizativa por PM. Efectuou-se corticoterapia e terapêutica com micofenolato com melhoria clínica, analítica e radiológica. Conclusão: Neste caso, foi a alteração na telerradiografia de tórax numa doente sem sintomatologia respiratória que levou ao estudo exaustivo até ao diagnóstico de PM, realçando mais uma vez a importância da telerradiografia no rastreio de patologias de outros foros. Abstract: Introduction: Polymyositis and dermatomyositis are classified as idiopathic inflammatory myopathies. Interstitial lung disease is rare and is described in the literature in about 10% of cases.The authors describes a case of 75 year old woman presenting with one month evolution of fever, weight loss, arthralgia, myalgia and symmetric and proximal muscle weakness of upper and lower limbs. Nonspecific interstitial changes was found in chest X-ray. After exhaustive study, the diagnosis of pulmonary envolvement in the form of organizing pneumonia by polymyositis, was established. Glucocorticoids and mycophenolate were prescribed with good clinical, analytical and radiological outcome. Conclusion: In this case, it was the changes in the chest X-ray in a patient without respiratory symptomatology, that conducted to exhaustive study to polymyositis diagnosis, enhancing once again the

  14. Spintronics: The molecular way

    Science.gov (United States)

    Cornia, Andrea; Seneor, Pierre

    2017-05-01

    Molecular spintronics is an interdisciplinary field at the interface between organic spintronics, molecular magnetism, molecular electronics and quantum computing, which is advancing fast and promises large technological payoffs.

  15. Utilization of human papillomavirus testing for cervical cancer prevention in a university hospital Utilização de método de biologia molecular para papilomavírus humano na prevenção do câncer de colo uterino em um hospital universitário

    Directory of Open Access Journals (Sweden)

    Rosekeila Simões Nomelini

    2007-06-01

    Full Text Available This study aimed to evaluate the performance and cost of using polymerase chain reaction (PCR and hybrid capture in the detection of cervical intraepithelial neoplasia (CIN in patients with cytological abnormalities (ASCUS/low-grade squamous intraepithelial lesion - LSIL, and the feasibility of implementing these methods in Brazil's Unified National Health System (SUS. Colposcopy gave a negative predictive value of 92.86% and efficiency of 87.8% for diagnosing CIN. The sensitivity of PCR and hybrid capture for detecting CIN was 83.33% and 66.67%, respectively, and the negative predictive value for diagnosing CIN2/CIN3 was 100% and 94.74%, respectively. The annual cost for 80 patients was lower when all patients with ASCUS/LSIL were referred for colposcopy than when HPV testing was performed and those with positive results were referred for colposcopy. Therefore, at present, it is financially unfeasible for the National Health System to implement HPV testing to screen patients with cytological abnormalities (ASCUS/LSIL. However, considering that large-scale use might make such methods cheaper, PCR should be the chosen method, since it is less expensive, more sensitive, and has a high negative predictive value.O trabalho objetivou avaliar o desempenho e o custo do PCR e captura híbrida na detecção de neoplasia intra-epitelial cervical (NIC em pacientes com anormalidades citológicas (ASCUS/lesões de baixo grau - LBG, e a viabilidade da implantação destes métodos no serviço público de saúde. Observou-se valor preditivo negativo de 92,86% e eficiência de 87,8% da colposcopia para diagnóstico de NIC. A sensibilidade do PCR e captura híbrida na detecção de NIC foi de 83,33% e 66,67%, respectivamente. O valor preditivo negativo no diagnóstico de NICII e III do PCR e captura híbrida foi de 100% e 94,74%, respectivamente. O custo anual das oitenta pacientes foi menor encaminhando-se todas as pacientes com ASCUS/ LBG à colposcopia do que

  16. Comprometimento pulmonar na leptospirose

    Directory of Open Access Journals (Sweden)

    Jorge Eduardo Manhães de Carvalho

    1992-03-01

    Full Text Available Em 23 pacientes com leptospirose apresentando comprometimento pulmonar, internados no Hospital Universitário Antônio Pedro da XJFF, Niterói, hemoptise e hemoptóicos foram observados em 21,7% e 30,4%, respectivajnente. Gasometria arterial revelou hipoxemia e hipocapnia na maioria dos casos. Radiografia de tórax em 15 pacientes mostrou comprometimento alveolar em 60%, comprometimento intersticial-reticular em 6%, padrão misto (alveolar e intersticial em20%e ausência de alterações radiológicas em 14%. A necrópsiade 13 pacientes mostrou edema, congestão e hemorragia nos pulmões em 100% dos casos. A hemorragia foi focal em 46% e difusa em 54% dos casos. Houve formação de membrana hialina em 30% e trombos de fibrina em 46% dos pulmões estudados, o que estabelece o diagnóstico da coagulação intravascular disseminada e a ocorrência da síndrome de angústia respiratória na leptospirose.

  17. Measurement of exchangeable sodium: 22Na or 24Na

    International Nuclear Information System (INIS)

    Smith, T.; Edmonds, C.J.

    1987-01-01

    A case is made for the use of 22 Na in low activities in preference to 24 Na for routine diagnostic estimation of exchangeable sodium, and is based chiefly on considerations of availability, cost and radiation dosimetry. A method in which only 37 kBq (1 μCi) 22 Na is administered orally is shown to be sufficiently accurate and to possess distinct advantages in terms of cost and convenience with a committed radiation dose no greater than that for a measurement using 24 Na. (author)

  18. The adsorption of hydrogen on a molecular sieve at -196{sup o}C and the observation of an isotope effect; Adsorption d'hydrogene sur un tamis moleculaire a -196{sup o}C et observation d'un effet isotopique; Absorbtsiya vodoroda na molekulyarnom fil'tre pri -196{sup o} i nablyudenie rezul'tatov dejstviya izotopov; Adsorcion de hidrogeno en un tamiz molecular a -196{sup o}C y observacion de un efecto isotopico

    Energy Technology Data Exchange (ETDEWEB)

    Duncombe, W G [Wellcome Research Laboratories, Beckenham, Kent (United Kingdom)

    1962-03-15

    adsorbio en el tamiz molecular cerca del 99 % del hidrogeno inicial antes de comenzar la desorcion por bombeo. Por lo tanto, parece probable que el considerable fraccionamiento observado tenga lugar principalmente durante la desorcion y que el efecto carezca de importancia cuando el tamiz se emplea para manipular pequenos volumenes de isotopos del hidrogeno ya que, por lo general, la desorcion total se efectuara por calentamiento. (author) [Russian] Ispytyvalsya molekulyarnyj fil'tr Linde 4 A v kachestve vozmozhnogo sredstva obrashcheniya s nebol'shimi ob{sup e}mami izotopov vodoroda v vakuume, vmesto primenyayushchegosya v nastoyashchee vremya nasosa Toiplera. Davlenie ravnovesiya (P) izmeryaetsya razlichnymi ob{sup e}mami (V) vodoroda, absorbiruemogo odnim grammom fil'tra pri temperature -196{sup o}. EHksperimenty s aktivirovannym drevesnym uglem pokazyvayut preimushchestvo fil'tra kak absorbenta vodoroda. Odin gramm fil'tra v sisteme s ob{sup e}mom v 500 ml absorbiruet okolo 97 % odnogo ml obraztsa vodoroda. Absorbtsiya neznachitel'na pri temperature -78{sup o}, i desorbtsiya yavlyaetsya kolichestvennoj i b'kpro protekaet pri komnatnoj temperature. Vozmozhnost' rezul'tatov dejstviya izotopa izuchalas' putem absorbirovaniya izmeryaemykh ob{sup e}mov tritiya (5 millikyuri/mol') pri ravnomernom davlenii okolo 5 mm, pri ehtom proiskhodilo vykachivanie sistemy v periode do 15 minut i izmerenie ob{sup e}ma ostatochnogo vodoroda. Poslednij prevrashchalsya kolichestvenno v vodu, zatem v butan i gaz. Udel'naya aktivnost' byla vsegda vyshe, chem aktivnost' tritiya, kotoryj prokhodil 10 tsiklov absorbtsii i desorbtsii bez promezhutochnogo vykachivaniya s tem, chtoby ne bylo nikakikh chistykh poter' gaza. EHto imelo takuyu zhe udel'nuyu aktivnost', kak u neobrabotannogo tritiya, vzyatogo iz rezervnoj kolby. Bylo obnaruzheno, chto logarifm (ostatochnyj ob{sup e}m/nachal'nyj ob{sup e}m) proportsionalen 1/logarifm (ostatochnaya udel'naya aktivnost'/ nachal'naya udel'naya aktivnost') v

  19. Distinct pH dependencies of Na+/K+ selectivity at the two faces of Na,K-ATPase.

    Science.gov (United States)

    Cornelius, Flemming; Tsunekawa, Naoki; Toyoshima, Chikashi

    2018-02-09

    The sodium pump (Na,K-ATPase) in animal cells is vital for actively maintaining ATP hydrolysis-powered Na + and K + electrochemical gradients across the cell membrane. These ion gradients drive co- and countertransport and are critical for establishing the membrane potential. It has been an enigma how Na,K-ATPase discriminates between Na + and K + , despite the pumped ion on each side being at a lower concentration than the other ion. Recent crystal structures of analogs of the intermediate conformations E2·Pi·2K + and Na + -bound E1∼P·ADP suggest that the dimensions of the respective binding sites in Na,K-ATPase are crucial in determining its selectivity. Here, we found that the selectivity at each membrane face is pH-dependent and that this dependence is unique for each face. Most notable was a strong increase in the specific affinity for K + at the extracellular face ( i.e. E2 conformation) as the pH is lowered from 7.5 to 5. We also observed a smaller increase in affinity for K + on the cytoplasmic side (E1 conformation), which reduced the selectivity for Na + Theoretical analysis of the p K a values of ion-coordinating acidic amino acid residues suggested that the face-specific pH dependences and Na + /K + selectivities may arise from the protonation or ionization of key residues. The increase in K + selectivity at low pH on the cytoplasmic face, for instance, appeared to be associated with Asp 808 protonation. We conclude that changes in the ionization state of coordinating residues in Na,K-ATPase could contribute to altering face-specific ion selectivity. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Molecular nanomagnets

    CERN Document Server

    Gatteschi, Dante; Villain, Jacques

    2006-01-01

    Nanomagnetism is a rapidly expanding area of research which appears to be able to provide novel applications. Magnetic molecules are at the very bottom of the possible size of nanomagnets and they provide a unique opportunity to observe the coexistence of classical and quantum properties. The discovery in the early 90's that a cluster comprising twelve manganese ions shows hysteresis of molecular origin, and later proved evidence of quantum effects, opened a new research area whichis still flourishing through the collaboration of chemists and physicists. This book is the first attempt to cover

  1. Molecular plasmonics

    CERN Document Server

    Fritzsche, Wolfgang

    2014-01-01

    Adopting a novel approach, this book provides a unique ""molecular perspective"" on plasmonics, concisely presenting the fundamentals and applications in a way suitable for beginners entering this hot field as well as for experienced researchers and practitioners. It begins by introducing readers to the optical effects that occur at the nanoscale and particularly their modification in the presence of biomolecules, followed by a concise yet thorough overview of the different methods for the actual fabrication of nanooptical materials. Further chapters address the relevant nanooptics, as well as

  2. The NA27 trigger

    International Nuclear Information System (INIS)

    Bizzarri, R.; Di Capua, E.; Falciano, S.; Iori, M.; Marel, G.; Piredda, G.; Zanello, L.; Haupt, L.; Hellman, S.; Holmgren, S.O.; Johansson, K.E.

    1985-05-01

    We have designed and implemented a minimum bias trigger together with a fiducial volume trigger for the experiment NA27, performed at the CERN SPS. A total of more than 3 million bubble chamber pictures have been taken with a triggered cross section smaller than 75% of the total inelastic cross section. Events containing charm particles were triggered with an efficiency of 98 +2 sub(-3)%. With the fiducial volume trigger, the probability for a picture to contain an interaction in the visible hydrogen increased from 47.3% to 59.5%, reducing film cost and processing effort with about 20%. The improvement in data taking rate is shown to be negligible. (author)

  3. Na Cauda do Cometa

    Science.gov (United States)

    Voelzke, M. R.

    2009-01-01

    Quando viam um cometa, os antigos gregos imaginavam uma estrela com uma vasta cabeleira. Não à toa, a palavra deriva do termo koma, que significa cabelo. Constituídos por fragmentos de gelo e gases, os cometas possuem um núcleo sólido, que pode ter vários quilômetros de diâmetro, e uma cauda que sempre aponta na direção contrária ao Sol, devido aos ventos solares. Graças à aparência de pontos luminosos em movimento (ao contrário de outros astros, que parecem estáticos), esses corpos celestes foram interpretados por diferentes povos com muito misticismo, inspirando mitos tanto de boas-novas como de maus presságios. Conheça algumas dessas histórias:

  4. NA48 prototype calorimeter

    CERN Multimedia

    1990-01-01

    This is a calorimeter, a detector which measures the energy of particles. When in use, it is filled with liquid krypton at -152°C. Electrons and photons passing through interact with the krypton, creating a shower of charged particles which are collected on the copper ribbons. The ribbons are aligned to an accuracy of a tenth of a millimetre. The folding at each end allows them to be kept absolutely flat. Each shower of particles also creates a signal in scintillating material embedded in the support disks. These flashes of light are transmitted to electronics by the optical fibres along the side of the detector. They give the time at which the interaction occurred. The photo shows the calorimeter at NA48, a CERN experiment which is trying to understand the lack of anti-matter in the Universe today.

  5. Efeito do ambiente pós-transporte na recuperação dos indicadores de estresse de pacus juvenis, Piaractus mesopotamicus = Effect of post-transport environment on the stress indicators recovery of pacu juveniles , Piaractus mesopotamicus

    Directory of Open Access Journals (Sweden)

    Leonardo Susumu Takahashi

    2006-10-01

    Full Text Available O objetivo deste trabalho foi avaliar a recuperação das respostas fisiológicas de estresse após transporte de pacus em diferentes condições de es tocagem. Após transporte por 2h30min, os peixes foram transferidos para tanque de terra ou para caixas de polietileno em laboratório. Houve significativa redução dos valores de cortisol observados na chegada 24 horas depois, nas duas condições de estocagem , enquanto a concentração de glicose caiu significativamente 72 horas depois nos peixes estocados no tanque de t 1erra e 120 horas nos peixes estocados no laboratório. A osmolalidade, sódio, potássio e cloreto suger em um retorno à homeostase durante o perío do de recuperação, principalmente nos peixes no tanque de terra. Os parâmetros hematológicos, sem efeito da condição de estocagem, não se caracterizaram indicadores sensíveis. Após o transporte, uma prática de manejo que causa estresse em peixes, o retorno às condições normais foi favorecido quando os pacus foram estocados em tanque de terra.The aim of this work was to evaluate the recovery of physiological stress responses after the transport of pacu juveniles in different stocking conditions. After being transported for 2 h30min, fish were transferred to earthen ponds or indoor polyethylene boxes. There was a significant reduction of cortisol values registered at fish arrival , 24 hours after, in both stocking conditions . The glucose concentration reduced significantly 72 hours after in fish stocked in earthen ponds , and 120 hours in fish stocked indoor. Osmolality, sodium, potassium and chloride behavior suggested the re-establishment of the homeostasis during the recovery period, mainly in fish kept in the earthen ponds. Concerning the hematological parameters, only hemoglobin concentration reduced significantly in the recovery period , without effect of stockingcondition, which does not characterize feasible indicators. After transport, a management

  6. Impacto dos nutrientes na saúde óssea: novas tendências Nutrients impact on bone health: new trends

    Directory of Open Access Journals (Sweden)

    Glaucia Queiroz Morais

    2007-07-01

    Full Text Available A nutrição é fator importante modificável no desenvolvimento/manutenção da massa óssea (MO e prevenção da osteoporose. Esta é uma doença caracterizada por decréscimo na massa esquelética e elevação da suscetibilidade a fraturas. O desenvolvimento do pico de massa óssea (PMO é ainda o maior determinante dessa condição. Por isso, alterações com a idade sinalizam a importância da manutenção de nutrição adequada durante o desenvolvimento desse pico. Indivíduos que atingiram elevado PMO terão, na idade adulta, baixo risco de desenvolver doenças osteometabólicas com o envelhecimento. Os efeitos dos nutrientes sobre as estruturas esqueléticas são intensos e amplos; alguns, há anos, são consistentemente relacionados com a saúde óssea, como o cálcio, fósforo e vitamina D. Entretanto, outros nutrientes vêm sendo sugeridos como essenciais para o metabolismo ósseo normal: proteínas, lipídeos, potássio, vitaminas K e A e cloreto de sódio. A influência das interações entre tais fatores nutricionais, meio ambiente, estilo de vida e hereditariedade auxiliarão na compreensão da complexidade do desenvolvimento da osteoporose e subseqüentes fraturas. Em adição, déficit energético pode acarretar redução da MO, em face dos distúrbios endócrino-metabólicos desencadeados pela privação alimentar. Esta revisão objetiva elucidar o impacto dos nutrientes e ingestão calórica sobre o osso, em diferentes estágios da vida, descrevendo possíveis interações entre nutrientes e como estas poderiam afetar a homeostase óssea e mineral.Nutrition is an important factor in bone mass development/maintenance and in osteoporosis prevention. This disease is characterized by decreased skeletal mass and increased susceptibility to fractures. The greatest determinant of this condition is the peak bone mass (PBM. Hence, alterations over time indicate the importance of maintaining adequate nutrition during the development of

  7. A ENGENHARIA NA ESCOLA

    Directory of Open Access Journals (Sweden)

    Valéria Pelizzer Casara

    2015-04-01

    Full Text Available Este projeto teve por objetivo principal mostrar às jovens do ensino médio, como as áreas de exatas e de engenharia podem estar inseridas em situações rotineiras por elas vivenciadas e incentivá-las para ingressarem nessas áreas. O projeto foi executado na escola de ensino Médio Nelson Horostecki na cidade de Chapecó, Santa Catarina. Mostrou-se de forma simples que as áreas de exatas e de engenharia têm aplicações práticas nas nossas vidas. No desenvolvimento do projeto, realizaram-se oficinas na escola cujo tema principal abordado foi o processo de fabricação do chocolate, visto que o mesmo é um produto muito apreciado pelas adolescentes. Dentro dessa temática, foram trabalhadas as questões que envolvem conhecimentos das áreas de exatas e de engenharia, mais especificamente a Engenharia Ambiental. O projeto auxiliou na formação cidadã e também na escolha profissional das meninas. Muitas das alunas participantes nunca haviam tido contato direto com alunos graduandos de cursos na área das exatas. Mais ainda, este projeto oportunizou a aproximação da universidade com a comunidade externa. Palavras-chave: Extensão Universitária, Ciências Exatas e Engenharia, Chocolate, Oficinas.   Engineering in the school Abstract: The main objective of this project was to show high school female students how the exact sciences and engineering can be included in their routine situations encouraging them to entering in these areas. The project was carried out at the Nelson Horostecki High School in Chapecó, Santa Catarina State, Brazil. It was showed in a simple manner how exact sciences and engineering have practical applications in our lives. Workshops were conducted in the school during the execution of the project in which the main subject was the chocolate manufacturing process, since chocolate is a product greatly appreciated by the young female people. Within this matter, the activities were performed using the knowledge of

  8. A Chimeric NaV1.8 Channel Expression System Based on HEK293T Cell Line

    Directory of Open Access Journals (Sweden)

    Xi Zhou

    2018-04-01

    Full Text Available Among the nine voltage-gated sodium channel (NaV subtypes, NaV1.8 is an attractive therapeutic target for pain. The heterologous expression of recombinant NaV1.8 currents is of particular importance for its electrophysiological and pharmacological studies. However, NaV1.8 expresses no or low-level functional currents when transiently transfected into non-neuronal cell lines. The present study aims to explore the molecular determinants limiting its functional expression and accordingly establish a functional NaV1.8 expression system. We conducted screening analysis of the NaV1.8 intracellular loops by constructing NaV chimeric channels and confirmed that the NaV1.8 C-terminus was the only limiting factor. Replacing this sequence with that of NaV1.4, NaV1.5, or NaV1.7 constructed functional channels (NaV1.8/1.4L5, NaV1.8/1.5L5, and NaV1.8/1.7L5, respectively, which expressed high-level NaV1.8-like currents in HEK293T cells. The chimeric channel NaV1.8/1.7L5 displayed much faster inactivation of its macroscopic currents than NaV1.8/1.4L5 and NaV1.8/1.5L5, and it was the most similar to wild-type NaV1.8 expressed in ND7/23 cells. Its currents were very stable during repetitive depolarizations, while its repriming kinetic was different from wild-type NaV1.8. Most importantly, NaV1.8/1.7L5 pharmacologically resembled wild-type NaV1.8 as revealed by testing their susceptibility to two NaV1.8 selective antagonists, APETx-2 and MrVIB. NaV chimeras study showed that at least the domain 2 and domain 4 of NaV1.8 were involved in binding with APETx-2. Our study provided new insights into the function of NaV1.8 intracellular loops, as well as a reliable and convenient expression system which could be useful in NaV1.8 studies.

  9. Mechanism of potassium ion uptake by the Na+/K+-ATPase

    Science.gov (United States)

    Castillo, Juan P.; Rui, Huan; Basilio, Daniel; Das, Avisek; Roux, Benoît; Latorre, Ramon; Bezanilla, Francisco; Holmgren, Miguel

    2015-07-01

    The Na+/K+-ATPase restores sodium (Na+) and potassium (K+) electrochemical gradients dissipated by action potentials and ion-coupled transport processes. As ions are transported, they become transiently trapped between intracellular and extracellular gates. Once the external gate opens, three Na+ ions are released, followed by the binding and occlusion of two K+ ions. While the mechanisms of Na+ release have been well characterized by the study of transient Na+ currents, smaller and faster transient currents mediated by external K+ have been more difficult to study. Here we show that external K+ ions travelling to their binding sites sense only a small fraction of the electric field as they rapidly and simultaneously become occluded. Consistent with these results, molecular dynamics simulations of a pump model show a wide water-filled access channel connecting the binding site to the external solution. These results suggest a mechanism of K+ gating different from that of Na+ occlusion.

  10. Investigation on U - O - Na, Pu - O - Na and U,Pu - O - Na phase diagrams

    International Nuclear Information System (INIS)

    Pillon, S.

    1989-03-01

    The thermochemical interaction between the nuclear fuel (uranium and plutonium mixed oxides) and the sodium has been investigated and particularly the three phase diagrams: U - O - Na; Pu - O - Na; U,Pu - O - Na. High temperature neutron diffraction, microcalorimetry and powder X-ray diffraction were used for the characterization of the compounds synthetized. This study allowed to complete the knowledge about each of these diagrams and to measure some physical and thermal properties on the compounds. The limits on the modelization of the fuel-sodium interaction are discussed from the results of the UO 2 - Na reaction [fr

  11. Specialized functional diversity and interactions of the Na,K-ATPase

    Directory of Open Access Journals (Sweden)

    Igor I. Krivoi

    2016-05-01

    Full Text Available Na,K-ATPase is a protein ubiquitously expressed in the plasma membrane of all animal cells and vitally essential for their functions. A specialized functional diversity of the Na,K-ATPase isozymes is provided by molecular heterogeneity, distinct subcellular localizations and functional interactions with molecular environment. Studies over the last decades clearly demonstrated complex and isoform-specific reciprocal functional interactions between the Na,K-ATPase and neighboring proteins and lipids. These interactions are enabled by a spatially restricted ion homeostasis, direct protein-protein/lipid interactions and protein kinase signaling pathways. In addition to its ‘classical’ function in ion translocation, the Na,K-ATPase is now considered as one of the most important signaling molecules in neuronal, epithelial, skeletal, cardiac and vascular tissues. Accordingly, the Na,K-ATPase forms specialized sub-cellular multimolecular microdomains which act as receptors to circulating endogenous cardiotonic steroids triggering a number of signaling pathways. Changes in these endogenous cardiotonic steroid levels and initiated signaling responses have significant adaptive values for tissues and whole organisms under numerous physiological and pathophysiological conditions. This review discusses recent progress in the studies of functional interactions between the Na,K-ATPase and molecular microenvironment, the Na,K-ATPase-dependent signaling pathways and their significance for diversity of cell function.

  12. Progress on molecular imaging

    International Nuclear Information System (INIS)

    Chen Quan; Zhang Yongxue

    2011-01-01

    Molecular imaging is a new era of medical imaging,which can non-invasively monitor biological processes at the cellular and molecular level in vivo, including molecular imaging of nuclear medicine, magnetic resonance molecular imaging, ultrasound molecular imaging,optical molecular imaging and molecular imaging with X-ray. Recently, with the development of multi-subjects amalgamation, multimodal molecular imaging technology has been applied in clinical imaging, such as PET-CT and PET-MRI. We believe that with development of molecular probe and multi-modal imaging, more and more molecular imaging techniques will be applied in clinical diagnosis and treatment. (authors)

  13. alpha-Adducin mutations increase Na/K pump activity in renal cells by affecting constitutive endocytosis: implications for tubular Na reabsorption.

    Science.gov (United States)

    Torielli, Lucia; Tivodar, Simona; Montella, Rosa Chiara; Iacone, Roberto; Padoani, Gloria; Tarsini, Paolo; Russo, Ornella; Sarnataro, Daniela; Strazzullo, Pasquale; Ferrari, Patrizia; Bianchi, Giuseppe; Zurzolo, Chiara

    2008-08-01

    Genetic variation in alpha-adducin cytoskeletal protein is implicated in the polymerization and bundling of actin and alteration of the Na/K pump, resulting in abnormal renal sodium transport and hypertension in Milan hypertensive rats and humans. To investigate the molecular involvement of alpha-adducin in controlling Na/K pump activity, wild-type or mutated rat and human alpha-adducin forms were, respectively, transfected into several renal cell lines. Through multiple experimental approaches (microscopy, enzymatic assays, coimmunoprecipitation), we showed that rat and human mutated forms increased Na/K pump activity and the number of pump units; moreover, both variants coimmunoprecipitate with Na/K pump. The increased Na/K pump activity was not due to changes in its basolateral localization, but to an alteration of Na/K pump residential time on the plasma membrane. Indeed, both rat and human mutated variants reduced constitutive Na/K pump endocytosis and similarly affected transferrin receptor trafficking and fluid-phase endocytosis. In fact, alpha-adducin was detected in clathrin-coated vesicles and coimmunoprecipitated with clathrin. These results indicate that adducin, besides its modulatory effects on actin cytoskeleton dynamics, might play a direct role in clathrin-dependent endocytosis. The constitutive reduction of the Na/K pump endocytic rate induced by mutated adducin variants may be relevant in Na-dependent hypertension.

  14. Valores na escola

    Directory of Open Access Journals (Sweden)

    Menin Maria Suzana De Stefano

    2002-01-01

    Full Text Available Neste texto pretende-se discorrer sobre valores morais na escola e suas implicações para a formação de professores. Para tanto discutir-se-á, em primeiro lugar, e brevemente, o que são valores morais, ou éticos, e como a escola pode situar-se em relação a eles. Em seguida, serão relatadas algumas observações a respeito de valores de professores e práticas daí decorrentes. São comentados resultados de pesquisa que ilustram a transmissão de valores de forma doutrinal e a educação moral e cívica tal como realizada na ditadura militar, e, por outro lado, a posição relativista e/ou de laissez-faire que certas escolas podem adotar, metodologicamente, sobre a educação em valores. Finalmente, defender-se-á a idéia de que é necessária uma discussão sobre valores pelos diversos membros da escola e uma opção por uma metodologia para ensiná-los, seja os professores, em sua formação inicial e continuada, seja os alunos. A teoria de desenvolvimento moral de Jean Piaget será apresentada como uma referência possível para a educação em valores. Exemplos de situações escolares de conflito de valores entre direção, pais e alunos são discutidas para ilustrar como uma escola pode adotar um procedimento democrático de educação em valores, que se apresenta como um terceiro caminho possível de educação moral nas escolas, além das posições doutrinárias ou relativistas.

  15. A influência dos ácidos graxos trans na disfunção da célula endotelial e o possível efeito terapêutico do exercício sobre o tecido endotelial como forma de prevenção ou regressão da aterosclerose Influence of trans fatty acids on endothelial cell dysfunction and possible therapeutic effects of physical activity on endothelial tissue for prevention or regression of atherosclerosis

    Directory of Open Access Journals (Sweden)

    Laureane Nunes Masi

    2009-06-01

    Full Text Available O endotélio atua ativamente na regulação do tônus vascular, sintetizando e liberando substâncias vasoativas. A inflamação e os fatores de risco cardiovasculares alteram a homeostase vascular, levando à disfunção endotelial e possível formação de placas de ateroma. O aumento das concentrações plasmáticas de ácidos graxos livres pode causar lipotoxicidade vascular, disfunção do endotélio e, finalmente, aterosclerose. Dieta rica em lipídeos contendo ácidos graxos trans tem correlação positiva com a progressão de doenças cardiovasculares. Mudanças no estilo de vida, na adoção de dieta balanceada e atividade física são estratégias para a prevenção de doenças cardiovasculares e a reabilitação de pacientes. Nesta revisão, discutimos a influência benéfica do exercício físico em aspectos importantes da disfunção endotelial causados pelos ácidos graxos trans, incluindo evidências recentes e/ou ainda não exploradas. Discutimos também quais seriam os mecanismos envolvidos no comprometimento funcional da célula endotelial frente ao aumento de ácidos graxos trans na circulação.The endothelium actively participates in the regulation of vascular tone through the synthesis and release of vasoactive mediators. Inflammation and cardiovascular risk factors affect vascular homeostasis, causing endothelial dysfunction and atheromatous plaque formation. Increased free fatty acid concentrations may result in vascular lipotoxicity, endothelium dysfunction and, ultimately, atherosclerosis. A lipid-rich diet including trans fatty acids has a positive correlation with the progression of cardiovascular diseases. Lifestyle changes, such as eating a well-balanced diet and participating in regular physical activity, have been proposed to prevent cardiovascular diseases and improve rehabilitation. In this review, we discuss the beneficial effects of regular exercise on important aspects of endothelial dysfunction caused by

  16. Molecular Recognition Involving Anthraquinone Derivatives and Molecular Clips

    Science.gov (United States)

    Alaparthi, Madhubabu

    In the past, we have demonstrated that 1,8-anthraquinone-18-crown-5 (1) and its heterocyclic derivatives act as luminescent hosts for a variety of cations of environmental and clinical concern. We report here a series of heteroatom-substituted macrocycles containing an anthraquinone moiety as a fluorescent signaling unit and a cyclic polyheteroether chain as the receptor. Sulfur, selenium, and tellurium derivatives of 1,8-anthraquinone-18-crown-5 (1) were synthesized by reacting sodium sulfide (Na2S), sodium selenide (Na2Se) and sodium telluride (Na2Te) with 1,8-bis(2-bromoethylethyleneoxy)anthracene - 9,10-dione in a 1:1 ratio (2,3, and 6). These sensors bind metal ions in a 1:1 ratio (7 and 8), and the optical properties of the new complexes were examined and the sulfur and selenium analogues show that selectivity for Pb(II) is markedly improved as compared to the oxygen analogue 1 which was competitive for Ca(II) ion. Selective reduction of 1 yields secondary alcohols where either one or both of the anthraquinone carbonyl groups has been reduced ( 15 and 9). A new mechanism for the fluorescence detection of metal cations in solution is introduced involving a unique keto-enol tautomerization. Reduction of 1 yields the doubly reduced secondary alcohol, 9. 9 acts as a chemodosimeter for Al(III) ion producing a strong blue emission due to the formation of the anthracene fluorophore, 10, via dehydration of the internal secondary alcohol in DMSO/aqueous solution. The enol form is not the most thermodynamically stable form under these conditions however, and slowly converts to the keto form 11.. Currently we are focusing on cucurbituril derivatives, also described as molecular clips due to their folded geometry used as molecular recognition hosts. We first investigated the synthesis and characterization of aromatic methoxy/catechol terminated cucurbituril units that act as hosts for small solvent molecules, such as CH2Cl2, CH3CN, DMF, and MeOH, through dual pi...H-C T

  17. Na+/H+ Exchange Activity in the Plasma Membrane of Arabidopsis1

    Science.gov (United States)

    Qiu, Quan-Sheng; Barkla, Bronwyn J.; Vera-Estrella, Rosario; Zhu, Jian-Kang; Schumaker, Karen S.

    2003-01-01

    In plants, Na+/H+ exchangers in the plasma membrane are critical for growth in high levels of salt, removing toxic Na+ from the cytoplasm by transport out of the cell. The molecular identity of a plasma membrane Na+/H+ exchanger in Arabidopsis (SOS1) has recently been determined. In this study, immunological analysis provided evidence that SOS1 localizes to the plasma membrane of leaves and roots. To characterize the transport activity of this protein, purified plasma membrane vesicles were isolated from leaves of Arabidopsis. Na+/H+ exchange activity, monitored as the ability of Na to dissipate an established pH gradient, was absent in plants grown without salt. However, exchange activity was induced when plants were grown in 250 mm NaCl and increased with prolonged salt exposure up to 8 d. H+-coupled exchange was specific for Na, because chloride salts of other monovalent cations did not dissipate the pH gradient. Na+/H+ exchange activity was dependent on Na (substrate) concentration, and kinetic analysis indicated that the affinity (apparent Km) of the transporter for Na+ is 22.8 mm. Data from two experimental approaches supports electroneutral exchange (one Na+ exchanged for one proton): (a) no change in membrane potential was measured during the exchange reaction, and (b) Na+/H+ exchange was unaffected by the presence or absence of a membrane potential. Results from this research provide a framework for future studies into the regulation of the plant plasma membrane Na+/H+ exchanger and its relative contribution to the maintenance of cellular Na+ homeostasis during plant growth in salt. PMID:12805632

  18. Na+/H+ exchange activity in the plasma membrane of Arabidopsis.

    Science.gov (United States)

    Qiu, Quan-Sheng; Barkla, Bronwyn J; Vera-Estrella, Rosario; Zhu, Jian-Kang; Schumaker, Karen S

    2003-06-01

    In plants, Na+/H+ exchangers in the plasma membrane are critical for growth in high levels of salt, removing toxic Na+ from the cytoplasm by transport out of the cell. The molecular identity of a plasma membrane Na+/H+ exchanger in Arabidopsis (SOS1) has recently been determined. In this study, immunological analysis provided evidence that SOS1 localizes to the plasma membrane of leaves and roots. To characterize the transport activity of this protein, purified plasma membrane vesicles were isolated from leaves of Arabidopsis. Na+/H+ exchange activity, monitored as the ability of Na to dissipate an established pH gradient, was absent in plants grown without salt. However, exchange activity was induced when plants were grown in 250 mm NaCl and increased with prolonged salt exposure up to 8 d. H+-coupled exchange was specific for Na, because chloride salts of other monovalent cations did not dissipate the pH gradient. Na+/H+ exchange activity was dependent on Na (substrate) concentration, and kinetic analysis indicated that the affinity (apparent Km) of the transporter for Na+ is 22.8 mm. Data from two experimental approaches supports electroneutral exchange (one Na+ exchanged for one proton): (a) no change in membrane potential was measured during the exchange reaction, and (b) Na+/H+ exchange was unaffected by the presence or absence of a membrane potential. Results from this research provide a framework for future studies into the regulation of the plant plasma membrane Na+/H+ exchanger and its relative contribution to the maintenance of cellular Na+ homeostasis during plant growth in salt.

  19. Symbiodinium isolation by NaOH treatment.

    Science.gov (United States)

    Zamoum, Thamilla; Furla, Paola

    2012-11-15

    The presence of photosynthetic zooxanthellae (dinoflagellates) in the tissue of many cnidarians is the main reason for their ecological success (i.e. coral reefs). It could also be the main cause of their demise, as the worldwide bleaching of reef-building coral is nothing less than the breakdown of this symbiotic association. The stability of this relationship is the principal marker for the biomonitoring of cnidarian health. We have therefore developed a new, simple method to isolate zooxanthellae in a few steps using NaOH solution. The protocol was validated in three symbiotic cnidarian species: a sea anemone, a gorgonian and a coral. Our method allows the isolation of intact and viable zooxanthellae with better yields than classic methods, especially for species with a calcareous skeleton. Moreover, the isolated zooxanthellae were free of host nucleic contaminants, facilitating subsequent specific molecular analyses.

  20. A aposta na filosofia

    Directory of Open Access Journals (Sweden)

    Márcio Suzuki

    2011-12-01

    Full Text Available Para Hume, filosofar é uma atividade semelhante às demais ocupações humanas. A decisão que leva à atividade filosófica é menos resultado de uma argumentação teórica do que fruto de um cálculo prático, que é entendido como uma caça ou um jogo. O objetivo deste trabalho será o de mostrar que no jogo filosófico perde quem joga sério demais. A aposta na filosofia tem que passar pelo bom humor e pela diversão: uma resposta a Pascal?For Hume, philosophy is in itself neither more nor less important than other human activities. On the contrary, it can be explained from its resemblance with game and hunting. If one chooses to dedicate himself to philosophy, his decision is not the consequence of logical reasoning, but depends on practical evaluation, which has something to do with gambling. The following text tries to show that in philosophy, like in other games, the loser will be the one who plays too earnestly. The philosophical game requires good humour and some relaxation: Is this a good answer to Pascal's pari?

  1. VPLIV OSEBNOSTI NA STILE VODENJA

    OpenAIRE

    Vučak, Petra

    2009-01-01

    Nekatere naše vrline krasijo zlate lastnosti, druge pa kvarijo sivi odtenki. Če bi ljudje razumeli in spoznali svojo osebnost, ter osebnostne tipe drugih ljudi, bi se problemi pri komunikaciji občutno zmanjšali. Takrat bi namreč lažje uvideli, zakaj je nekdo reagiral na način, kot je ali zakaj je nekdo dejal to, kar je. Smisel tega je, da spoznamo svoje dobre lastnosti, ki jih lahko še bolj razvijemo, slabe pa poskušamo nadzorovati in tako zmanjšati njihov vpliv. Iskanje uspešnih in učink...

  2. SPOLNO NADLEGOVANJE NA DELOVNEM MESTU

    OpenAIRE

    Rubič, Gašper

    2016-01-01

    V diplomskem delu smo v uvodu predstavili problem spolnega nadlegovanja na delovnem mestu in predstavili podjetje TEKSTIL d.d. V nadaljevanju smo z anketo raziskali, ali problem spolnega nadlegovanja na delovnem mestu v obravnavanem podjetju obstaja in če, kako se nanj odziva okolje. V teoretičnem delu smo nadaljevali in predstavili definicijo spolnega nadlegovanja, ki je kakršna koli oblika nezaželenega verbalnega in neverbalnega ali fizičnega ravnanja spolne narave z učinkom ali nameno...

  3. Active transport of Na+ by reconstituted Na,K-ATPase

    International Nuclear Information System (INIS)

    Boldyrev, A.A.; Svinukhova, I.A.

    1987-01-01

    The ability of ATP, CTP, ITP, GTP, and UTP to support ouabain-sensitive accumulation of Na + by proteoliposomes with a reconstituted Na/K-pump was investigated. At a low [Na + ]/[K + ] ratio in the medium (20 mM/50 mM), a correlation is observed between the proton-accepting capacity of the nucleotide and its effectiveness as a substrate of active transport. To test the hypothesis of the importance of the presence of a negative charge in the 1-position of the purine (3-pyrimidine) base of the nucleotide for mutual transitions between the Na- and K-conformations of Na,K-ATPase they used two analogs of ATP: N 1 -hydroxy-ATP, possessing proton acceptor capacity, and N 1 -methoxy-ATP, in the molecule of which the negative charge is quenched by a methyl group. The first substrate supports active accumulation of Na + in proteoliposomes at the same rate as ATP, whereas the second substrate is relatively ineffective

  4. Molecular Electronic Terms and Molecular Orbital Configurations.

    Science.gov (United States)

    Mazo, R. M.

    1990-01-01

    Discussed are the molecular electronic terms which can arise from a given electronic configuration. Considered are simple cases, molecular states, direct products, closed shells, and open shells. Two examples are provided. (CW)

  5. Photoaffinity labelling of a small protein component of a purified (Na+-K+)ATPase

    International Nuclear Information System (INIS)

    Rogers, T.B.; Lazdunski, M.

    1979-01-01

    Studies have been carried out on the photoaffinity labelling of the (Na + -K + )ATPase from the electric organ of Electrophorus electricus. The aims were to see if different photoaffinity labels of the ouabain binding site, are capable of labelling a small protein component and to know if there is a small protein component, in addition to the major protein chains with molecular weights in the regions of 100 000 and 50 000, which is present in other purified (Na + -K + )ATPase preparations. (Auth.)

  6. Beam monitoring at NA2

    CERN Multimedia

    1978-01-01

    Claus Goessling working on the beam Cerenkov counter of NA2. The muon beam enters from left the hall EHN2 and the last element of the beam transport. On background is the access door on the Jura side.

  7. An ab initio molecular

    Indian Academy of Sciences (India)

    mechanisms of two molecular crystals: An ab initio molecular dynamics ... for Computation in Molecular and Materials Science and Department of Chemistry, School of ..... NSAF Foundation of National Natural Science Foun- ... Matter 14 2717.

  8. Risbjerg: Historisk stemmeskred med NA

    DEFF Research Database (Denmark)

    Thomsen, Søren Risbjerg

    2007-01-01

    ANALYSE: NA flytter 12,3 pct. af stemmerne i majs meningsmålinger - historisk mange vælgere på en måned, skriver professor Risbjerg. Udgivelsesdato: 3. juni 2007......ANALYSE: NA flytter 12,3 pct. af stemmerne i majs meningsmålinger - historisk mange vælgere på en måned, skriver professor Risbjerg. Udgivelsesdato: 3. juni 2007...

  9. Na via do Behemoth

    Directory of Open Access Journals (Sweden)

    Gérard Rabinovitch

    2008-06-01

    Full Text Available O momento nazista permanece um enigma impensado de que a cultura contemporânea continua cativa. O autor levanta a hipótese de que a persistência desse enigma e seus estragos duráveis se devem à insistência dos pensamentos político, sociológico e filosófico em construírem o nazismo à luz da metáfora hobbesiana do Leviatã. Propõe retomar a questão do nazismo sob a perspectiva do Behemoth, antônimo do Leviatã. Para tanto, sugere a necessidade de retornar a Freud e à psicanálise, balizas de um possível novo pensamento do político que escrutine a destrutividade nazista. Propõe ainda sondar as homologias entre nazismo, corjas e máfias, com base na figura da " heroicização da violência" que lhes seria comum. E avança um modelo " econômico" : a quimera, suscetível de capturar o caráter heterotópico e heterocrônico de sua construção criminosa.The paths of Behemoth. The Nazi moment remains as the thoughtless enigma of which contemporary culture is still captive. The author raises the hypothesis where the persistency of this enigma and its durable damages are due to the insistence of the political, social and philosophical thoughts in building the Nazism at the view of the Hobbesian metaphor of Leviathan. It is here proposed to resume the Nazism matter under Behemoth's perspective, antonym to Leviathan. For such, it is suggested a necessity to look back at Freud and the psychoanalysis, structured by a possible new political thought which scrutinizes the destructivity of the Nazism. It is also here proposed to gaze at the homologies between Nazism, mafias and gangs, with a base in the figure of " violence as a heroically act" that are their common ground. The author also advances an economical model: the chimera susceptible to capture the heterotopic and heterochronic character of its criminal construction.

  10. Molecular dynamics simulations of cluster fission and fusion processes

    DEFF Research Database (Denmark)

    Lyalin, Andrey G.; Obolensky, Oleg I.; Solov'yov, Ilia

    2004-01-01

    Results of molecular dynamics simulations of fission reactions Na_10^2+ --> Na_7^+ +Na_3^+ and Na_18^2+ --> 2Na_9^+ are presented. The dependence of the fission barriers on the isomer structure of the parent cluster is analyzed. It is demonstrated that the energy necessary for removing homothetic...... separation of the daughter fragments begins and/or forming a "neck" between the separating fragments. A novel algorithm for modeling the cluster growth process is described. This approach is based on dynamic search for the most stable cluster isomers and allows one to find the optimized cluster geometries...... groups of atoms from the parent cluster is largely independent of the isomer form of the parent cluster. The importance of rearrangement of the cluster structure during the fission process is elucidated. This rearrangement may include transition to another isomer state of the parent cluster before actual...

  11. [Effect of adaptogenic preparations on Na+/H+-antiporter function in plasma membrane of corn root cells under salinity conditions].

    Science.gov (United States)

    Kovalenko, N O; Bilyk, Zh I; Palladina, T O

    2014-01-01

    Salinity is a hard stress factor for plant organisms which negative effect is caused chiefly by sodium toxic for plants. Plant cells try to remove Na+ from their cytoplasm outside and to vacuolar space by secondary active Na+/H+-antiporters. Their functions can be intensified by gene engineering methods however we try do it with the help of non-toxic bioactive preparations. A comparison of their effect on the plasma membrane of Na+/H+-antiporters was carried out on corn seedling roots of Zea mays L. exposed at 0.1 M NaCl. Before we have established that Methyure used by seed pretreating possesses a high salt protective ability as against Ivine. It was found that without NaCl exposition Na+/H+-antiporter activity in root plasma membrane was nearly unnoticeable but increased slightly with seedling age. Methyure and Ivine did not influence its activity in control root seedling. One day 0.1 M NaCl exposition evoked a considerable increasing of Na+/H+-antiporter activity and its gene expression but these effects disappeared at 10 day NaCl exposition. Methyure use reinforced Na+/H+-antiporter activity and prolonged it at NaCl exposition without effect on its gene expression whereas Ivine effects on these indexes were insignificant. Obtained results showed that the salt protective capability of Methyure is connected with plasma membrane Na+/H+-antiporter activation which is realized on molecular level.

  12. Total serum vitamin C concentration in pregnant women: implications for a healthy pregnancy Concentração total de vitamina C na gestante: implicações para uma gestação saudável

    Directory of Open Access Journals (Sweden)

    Garba Ibrahim Hassan

    2006-09-01

    Full Text Available OBJECTIVES: total serum vitamin C (L-ascorbic acid concentration was measured in 90 pregnant women, 30 in each trimester (age range 18-35 years and a control group of age-matched non-pregnant women. METHODS: total serum vitamin C concentration was measured using the 2.4-dinitrophenylhydrazine method which involves the conversion of vitamin C to dehydroascorbic acid in the presence of copper (II ions and subsequent measurement of the resulting bis-hydrazone at 540nm. RESULTS: the total vitamin C concentration in the first trimester was 2.55 ± 0.82 mg/dl and 2.32 ± 0.40 mg/dl and 0.77 ± 0.10 mg/dl in the second and third trimesters respectively. Relative to serum total vitamin C concentration in the controls (3.15 ± 0.13 mg/dl these values are significantly lower (p OBJETIVOS: a concentração sérica total de vitamina C (ácido 1-ascórbico foi medida em 90 mulheres grávidas sendo 30 em cada trimestre (idade de 18-35 anos e um grupo controle, pareado por idade, de mulheres não grávidas. MÉTODOS: a concentração sérica total de vitamina C foi medida usando o método 2.4-dinitrofenilhidrazina que envolve a conversão de vitama C a ácido dehidroascorbico na presença de íons cobre II e, em seguida, medindo a resultante bi-hidrazona em 540 nm. RESULTADOS: a concentração total de vitamina C no primeiro semestre foi de 2.55 ± 0,13 mg/dL e de 2,32 ± 0,40 mg/dL e 0,77 ± 0,10 mg/dL no segundo e terceiro trimestres, respectivamente. Estes valores são significativamente mais baixos do que nos controles (3,15 ± 0,13 mg/dL(p<0,05. CONCLUSÕES: reduzida concentração de vitamina C sérica na gestação pode indicar a sua utilização para retirar o excesso de espécies oxigênio-reativas e manter a homeostase normal. Assim, recomenda-se a suplementação de vitamina C na gestação para aumentar o seu baixo nível no organismo e previnir a predisposição para o baixo peso ao nascer, parto prematuro e pré-eclâmpsia, condições associadas

  13. Aspects of gene structure and functional regulation of the isozymes of Na,K-ATPase

    DEFF Research Database (Denmark)

    Jorgensen, P.L.

    2001-01-01

    genomes, the genes of four alpha-subunit and at least three beta-subunit isoforms of Na,K-ATPase are identified and two gamma-subunits are expressed in kidney. The isoforms combine in a number of Na,K-ATPase isozymes that are expressed in a tissue and cell specific manner. Models of the molecular...... mechanism of regulation of these isozymes have become more reliable due to progress in understanding the three-dimensional protein structure and conformational transitions mediating transfer of energy from the P-domain to intramembrane Na+ and K+ binding sites....

  14. Hydrothermal Synthesis and Electrochemical Performance of Manganese Oxide (Na-OMS-2) Nanorods.

    Science.gov (United States)

    Zhang, Qing; Xu, Shan; Zheng, Hao; Luo, Zhaohui; Liu, Kang; Wang, Wei; Li, Guohua; Wang, Shiquan; Liu, Jianwen; Feng, Chuanqi

    2017-02-01

    Sodium octahedral molecular sieve nanorods (Na-OMS-2) were prepared through a facile hydrothermal method. The effects of reaction temperature and duration on particle sizes of the products were investigated. The electrochemical performance of samples was studied by constant current charge–discharge tests as cathode material for Li-ion batteries (LIBs). The initial discharge capacity of Na-OMS-2 is 123.4 mAh g−1 and the capacity retention was 123.9 mAh g−1 after 100 cycles. The result demonstrates that Na-OMS-2 cathode material behaves a good cycling stability.

  15. Financiranje projekata na pomorskom dobru

    Directory of Open Access Journals (Sweden)

    Zoran Tasić

    2018-02-01

    Full Text Available Koncesije otvaraju vrlo osjetljiva politička, ekonomska i pravna pitanja u mnogim državama svijeta. Samo definiranje pojma koncesije često je komplicirana i ne sasvim jasna zadaća. OECD je prihvatila definiciju koncesije kao: ’’davanje prava privatnom trgovačkom društvu da može gospodarski upravljati određenom infrastrukturnim uslugama i za to zarađivati naknadu. Koncesionar dobija u posjed određene objekte (ali vlasništvo na tim objektima ostaje u rukama države te ih koristi u svrhu obavljanja određene djelatnosti ili usluge sukladno odredbama ugovora’’. Hrvatsko pravo definira koncesije načelno kao pravo stečeno temeljem ugovora o koncesiji, a sukladno uvjetima sadržanim u odluci o davanju koncesije (koju je donijelo odgovarajuće upravno tijelo, a u odnosu na pomorsko dobro, specifično, kao pravo državne vlasti da može dio pomorskog dobra, koje je inače dobro izvan pravnog prometa (res extra commercium, isključiti iz opće uporabe bilo dijelom ili u cijelosti, i dati ga fizičkoj ili pravnoj osobi na gospodarsko korištenje sukladno određenim prostornim planovima. Građevine i drugi objekti izgrađeni na pomorskom dobru čine njegov sastavni dio. Zakonom je jasno određeno da nikakva stvarna prava nisu dopuštena na pomorskom dobru, uključivo i na objektima izgrađenima na njemu. Projekti na pomorskom dobru često uključuju velike infrastrukturne projekte, razvoje luka i marina, koji iziskuju značajna financijska sredstva. Banke koje financiraju takve projekte zahtijevaju organiziran i transparentan zakonski okvir koncesija, slobodu ugovaranja, pravnu zaštitu svih strana uključenih u projekt (uključivo i mogućnost međunarodne arbitraže. (...

  16. Recikliranje plastenk na kreativen način

    OpenAIRE

    Pavlin, Suzana

    2017-01-01

    Plastenke, poleg ostalih plastičnih izdelkov, v zadnjih letih predstavljajo pravo katastrofo za okolje. Domnevamo, da se le redko kdo vpraša, kaj se zgodi z njo po tem, ko je iz nje zaužil še zadnjo kapljico vode. Plastenka je lahko kot večina ostalih komunalnih odpadkov ponovno uporabljena, reciklirana, sežgana ali odložena na deponijo. V primeru nespoštovanja Zakona o varstvu okolja pa pristane v naravi, pogosto v morju, kjer prav počasi razpada in negativno vpliva na celoten ekosistem. V d...

  17. All new for NA62

    CERN Multimedia

    Antonella Del Rosso

    2012-01-01

    This week sees the start of the first run of the new NA62 experiment. This will be a unique opportunity for the collaboration to test its new beam, new detectors and new data acquisition system before the physics run in 2014. Speaking to the Bulletin, the NA62 technical coordinator Ferdinand Hahn shares the many challenges that the various teams faced to be on time for beam. Ready, steady, start!   A Large Angle Veto detector (white) in place in the NA62 decay volume (blue). With components from almost all the detectors in place downstream of the decay point of the mother particles – the kaons – and of the KTAG detector that tags the kaons before they decay, NA62 is ready for its first technical run. This unique run will test all the equipment as well as the trigger and the data acquisition systems. “This year, we will have about five weeks of beam from the SPS before the long shutdown of all the CERN machines,” says Ferdinand Hahn, NA62 Technical Co-...

  18. Corpo e sexualidade na gravidez

    Directory of Open Access Journals (Sweden)

    Natalúcia Matos Araújo

    2012-06-01

    Full Text Available Estudo etnográfico que teve como objetivo compreender como as gestantes vivenciam os processos fisiológicos do seu corpo durante a gestação e a sua repercussão na sexualidade. A pesquisa envolveu sete mulheres residentes em bairro popular de São Paulo. Na coleta de dados, utilizou-se observação participante e entrevista com questões norteadoras. Os dados foram apresentados na forma de narrativa e posteriormente organizados nas categorias: Percebendo as transformações corporais; Convivendo com as mudanças no corpo; Sentimentos e sensações na vida sexual durante a gestação e imaginando o corpo e a sexualidade após a gestação. As mulheres referiram-se às transformações do corpo como desconfortos e expressaram a preocupação de que fossem definitivas. Expressaram o desejo de que, após o parto, o corpo volte a ser como era e que volte a sentir desejo sexual. O reconhecimento destes fatos constitui-se numa ferramenta primordial na adequação das práticas profissionais.

  19. Molecular HIV screening.

    Science.gov (United States)

    Bourlet, Thomas; Memmi, Meriam; Saoudin, Henia; Pozzetto, Bruno

    2013-09-01

    Nuclear acid testing is more and more used for the diagnosis of infectious diseases. This paper focuses on the use of molecular tools for HIV screening. The term 'screening' will be used under the meaning of first-line HIV molecular techniques performed on a routine basis, which excludes HIV molecular tests designed to confirm or infirm a newly discovered HIV-seropositive patient or other molecular tests performed for the follow-up of HIV-infected patients. The following items are developed successively: i) presentation of the variety of molecular tools used for molecular HIV screening, ii) use of HIV molecular tools for the screening of blood products, iii) use of HIV molecular tools for the screening of organs and tissue from human origin, iv) use of HIV molecular tools in medically assisted procreation and v) use of HIV molecular tools in neonates from HIV-infected mothers.

  20. Conformational changes of the cytoplasmic part of Na+/K+-ATPase induced by the ligand binding

    Czech Academy of Sciences Publication Activity Database

    Kubala, Martin; Gryčová, Lenka; Lánský, Zdeněk; Otyepka, M.

    2007-01-01

    Roč. 274, Suppl.1 (2007), s. 127-127 ISSN 1742-464X. [FEBS Congress Molecular Machines /32./. 07.07.2007-12.07.2007, Vienna] R&D Projects: GA ČR(CZ) GA203/07/0564 Institutional research plan: CEZ:AV0Z50110509 Keywords : cpo1 * Na+/K+- ATPase * molecular dynamic simulations * fluorescence quenching Subject RIV: BO - Biophysics

  1. Identification of a 3rd Na+ Binding Site of the Glycine Transporter, GlyT2.

    Directory of Open Access Journals (Sweden)

    Nandhitha Subramanian

    Full Text Available The Na+/Cl- dependent glycine transporters GlyT1 and GlyT2 regulate synaptic glycine concentrations. Glycine transport by GlyT2 is coupled to the co-transport of three Na+ ions, whereas transport by GlyT1 is coupled to the co-transport of only two Na+ ions. These differences in ion-flux coupling determine their respective concentrating capacities and have a direct bearing on their functional roles in synaptic transmission. The crystal structures of the closely related bacterial Na+-dependent leucine transporter, LeuTAa, and the Drosophila dopamine transporter, dDAT, have allowed prediction of two Na+ binding sites in GlyT2, but the physical location of the third Na+ site in GlyT2 is unknown. A bacterial betaine transporter, BetP, has also been crystallized and shows structural similarity to LeuTAa. Although betaine transport by BetP is coupled to the co-transport of two Na+ ions, the first Na+ site is not conserved between BetP and LeuTAa, the so called Na1' site. We hypothesized that the third Na+ binding site (Na3 site of GlyT2 corresponds to the BetP Na1' binding site. To identify the Na3 binding site of GlyT2, we performed molecular dynamics (MD simulations. Surprisingly, a Na+ placed at the location consistent with the Na1' site of BetP spontaneously dissociated from its initial location and bound instead to a novel Na3 site. Using a combination of MD simulations of a comparative model of GlyT2 together with an analysis of the functional properties of wild type and mutant GlyTs we have identified an electrostatically favorable novel third Na+ binding site in GlyT2 formed by Trp263 and Met276 in TM3, Ala481 in TM6 and Glu648 in TM10.

  2. gigapanorama of NA 62 cavern

    CERN Multimedia

    Brice, Maximilien

    2015-01-01

    The image shows the new rare Kaon decay experiment at CERN, called NA62. The NA62 experiment is 270 metres long and includes a 120-metre-long vacuum tank, shown here, housing several of the particle detectors. (Note: the experiment axis is a straight line, the curving of the tank is an optical effect of the photo.) Kaons are particles that decay into lighter elementary particles. The kaon decay processes are mostly well known, except for some very rare decay modes. For example, NA62 is investigating a rare decay predicted by the Standard Model in which a kaon decays into one pion and two neutrinos. This process occurs only once every 10 billion decays. The understanding of such ultra-rare decays are of great importance because they test the Standard Model in energy ranges not accessible by direct measurements. They are therefore complementary to the measurements at the LHC. ultra high definition on demand (photolab@cern.ch).

  3. Armas na escola: que fazer?

    Directory of Open Access Journals (Sweden)

    Raymundo de Lima

    2010-09-01

    Full Text Available

    Um aluno portava um revólver na sala de aula de uma escola de Maringá (O Diário, 30/07/2010. Ele pegou arma do pai, sem que este soubesse, para se proteger de garotos que o intimidavam. Trata-se de um caso isolado ou é hora de a escola tomar medidas preventivas? Semanas antes, tiros foram disparados dentro de uma faculdade da mesma cidade. O autor dos disparos está preso, e a faculdade tenta apagar as marcas com publicidade positiva na Tv. Em Campo Mourão, cidade a cerca de uma hora de Maringá, duas meninas foram mortas e enterradas na escola.

  4. OGLAŠEVANJE NA FACEBOOKU

    OpenAIRE

    Renko, Katica

    2013-01-01

    V magistrskem delu smo se seznanili z oglaševanjem na Facebooku. S pregledom gradiva, ki nam je ponujeno, smo preverili pogoje, načine, oblike … oglaševanja, ki pa smo jih s pregledom situacije v praksi preverili in dopolnili. Ob zaključku dela lahko rečemo, da je oglaševanje preko FB enostavnejše, cenejše, dostopnejše, omogoča nam ažurnost in samo komunikacijo z naslovniki, ki so potencialni kupci naših ponudb. Množični mediji nam omogočajo mnogotero obliko oglaševanja. Izbrana oblika ponuja...

  5. Understanding molecular structure from molecular mechanics.

    Science.gov (United States)

    Allinger, Norman L

    2011-04-01

    Molecular mechanics gives us a well known model of molecular structure. It is less widely recognized that valence bond theory gives us structures which offer a direct interpretation of molecular mechanics formulations and parameters. The electronic effects well-known in physical organic chemistry can be directly interpreted in terms of valence bond structures, and hence quantitatively calculated and understood. The basic theory is outlined in this paper, and examples of the effects, and their interpretation in illustrative examples is presented.

  6. K+ congeners that do not compromise Na+ activation of the Na+,K+-ATPase: hydration of the ion binding cavity likely controls ion selectivity.

    Science.gov (United States)

    Mahmmoud, Yasser A; Kopec, Wojciech; Khandelia, Himanshu

    2015-02-06

    The Na(+),K(+)-ATPase is essential for ionic homeostasis in animal cells. The dephosphoenzyme contains Na(+) selective inward facing sites, whereas the phosphoenzyme contains K(+) selective outward facing sites. Under normal physiological conditions, K(+) inhibits cytoplasmic Na(+) activation of the enzyme. Acetamidinium (Acet(+)) and formamidinium (Form(+)) have been shown to permeate the pump through the outward facing sites. Here, we show that these cations, unlike K(+), are unable to enter the inward facing sites in the dephosphorylated enzyme. Consistently, the organic cations exhibited little to no antagonism to cytoplasmic Na(+) activation. Na(+),K(+)-ATPase structures revealed a previously undescribed rotamer transition of the hydroxymethyl side chain of the absolutely conserved Thr(772) of the α-subunit. The side chain contributes its hydroxyl to Na(+) in site I in the E1 form and rotates to contribute its methyl group toward K(+) in the E2 form. Molecular dynamics simulations to the E1·AlF4 (-)·ADP·3Na(+) structure indicated that 1) bound organic cations differentially distorted the ion binding sites, 2) the hydroxymethyl of Thr(772) rotates to stabilize bound Form(+) through water molecules, and 3) the rotamer transition is mediated by water traffic into the ion binding cavity. Accordingly, dehydration induced by osmotic stress enhanced the interaction of the congeners with the outward facing sites and profoundly modified the organization of membrane domains of the α-subunit. These results assign a catalytic role for water in pump function, and shed light on a backbone-independent but a conformation-dependent switch between H-bond and dispersion contact as part of the catalytic mechanism of the Na(+),K(+)-ATPase. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. β decay of Na32

    Science.gov (United States)

    Mattoon, C. M.; Sarazin, F.; Hackman, G.; Cunningham, E. S.; Austin, R. A. E.; Ball, G. C.; Chakrawarthy, R. S.; Finlay, P.; Garrett, P. E.; Grinyer, G. F.; Hyland, B.; Koopmans, K. A.; Leslie, J. R.; Phillips, A. A.; Schumaker, M. A.; Scraggs, H. C.; Schwarzenberg, J.; Smith, M. B.; Svensson, C. E.; Waddington, J. C.; Walker, P. M.; Washbrook, B.; Zganjar, E.

    2007-01-01

    The β-decay of Na32 has been studied using β-γ coincidences. New transitions and levels are tentatively placed in the level scheme of Mg32 from an analysis of γ-γ and β-γ-γ coincidences. The observation of the indirect feeding of the 2321 keV state in Mg32 removes some restrictions previously placed on the spin assignment for this state. No evidence of a state at 2117 keV in Mg32 is found. Previously unobserved weak transitions up to 5.4 MeV were recorded but could not be placed in the decay scheme of Na32.

  8. Corpo-escrita na esquizofrenia

    OpenAIRE

    Bialer, Marina

    2014-01-01

    Este artigo aborda a importância do trabalho de escrita na esquizofrenia. Toma-se como ponto de partida a formulação lacaniana sobre o esquizofrênico como aquele que não tem as funções dos órgãos do seu corpo dadas pelos discursos estabelecidos. A hipótese de que o trabalho sobre a letra pode permitir o tratamento do gozo debordante na esquizofrenia é analisada pelo estudo da obra do escritor esquizofrênico Robert Walser, a qual evidencia a viabilidade da construção de um corpo pela escrita n...

  9. Insulin regulation of (Na+, K+)-ATPase

    International Nuclear Information System (INIS)

    Lytton, J.

    1985-01-01

    This thesis describes an investigation into the mechanism of insulin stimulation of (Na + ,K + )=ATPase in rat adipocytes. Two molecular forms of the catalytic subunit of the enzyme were identified and denoted α and α(+), due to their similarity to those isozymes previously described from rat brain. Insulin specifically stimulated the α(+) form of the enzyme. The two forms of the enzyme had quite different affinities for intracellular sodium ion; insulin affected only the lower affinity of α(+), shifting it toward a higher value. However, the sodium affinity of (Na + ,K + )-ATPase activity in isolated membranes was equally high for both forms of the enzyme. This suggests that the difference in sodium affinity between the two forms observed in the cell is not inherent within the structure of the sodium pump, but must depend upon a selective interaction with another molecule which has been lost upon membrane isolation. Immunoprecipitation of both the catalytic subunits either from extracts of whole cells which had been labelled with [ 32 P] orthophosphate, or from membranes which had been labelled with γ-[ 32 P]ATP demonstrated that less than 1 in 100 molecules had a covalently bound phosphate insulin had no influence on this value. The amino terminal sequences of the first 4 amino acids of the catalytic subunits of both α (isolated from rat kidney) and α(+) (from rat brainstem axolemma) were determined. The result shows two highly homologous but clearly different molecules. It can thus be concluded that the insulin sensitive version of the enzyme is not derived from the common α form by a post-translational modification

  10. Efeito do ambiente pós-transporte na recuperação dos indicadores de estresse de pacus juvenis, Piaractus mesopotamicus - DOI: 10.4025/actascianimsci.v28i4.610 Effect of post-transport environment on the stress indicators recovery of pacu juveniles , Piaractus mesopotamicus - DOI: 10.4025/actascianimsci.v28i4.610

    Directory of Open Access Journals (Sweden)

    Jaqueline Dalbello Biller

    2006-02-01

    Full Text Available O objetivo deste trabalho foi avaliar a recuperação das respostas fisiológicas de estresse após transporte de pacus em diferentes condições de es tocagem. Após transporte por 2h30min, os peixes foram transferidos para tanque de terra ou para caixas de polietileno em laboratório. Houve significativa redução dos valores de cortisol observados na chegada 24 horas depois, nas duas condições de estocagem , enquanto a concentração de glicose caiu significativamente 72 horas depois nos peixes estocados no tanque de t 1erra e 120 horas nos peixes estocados no laboratório. A osmolalidade, sódio, potássio e cloreto suger em um retorno à homeostase durante o perío do de recuperação, principalmente nos peixes no tanque de terra. Os parâmetros hematológicos, sem efeito da condição de estocagem, não se caracterizaram indicadores sensíveis. Após o transporte, uma prática de manejo que causa estresse em peixes, o retorno às condições normais foi favorecido quando os pacus foram estocados em tanque de terra.The aim of this work was to evaluate the recovery of physiological stress responses after the transport of pacu juveniles in different stocking conditions. After being transported for 2 h30min, fish were transferred to earthen ponds or indoor polyethylene boxes. There was a significant reduction of cortisol values registered at fish arrival , 24 hours after, in both stocking conditions . The glucose concentration reduced significantly 72 hours after in fish stocked in earthen ponds , and 120 hours in fish stocked indoor. Osmolality, sodium, potassium and chloride behavior suggested the re-establishment of the homeostasis during the recovery period, mainly in fish kept in the earthen ponds. Concerning the hematological parameters, only hemoglobin concentration reduced significantly in the recovery period , without effect of stocking condition, which does not characterize feasible indicators. After transport, a management

  11. Identification of CW two-photon transitions in Na2 and NaK

    International Nuclear Information System (INIS)

    Morgan, G.P.

    1983-01-01

    This thesis reports on the two-photon visible excitation spectra of sodium and potassium vapors. In the past, similar work has been performed on sodium and many atomic two-photon transitions have been characterized. However, many extra signals exist which do not possess the ground, 3S, state hyperfine splitting. These extra transitions are due to the sodium dimer Na 2 . 79 such transitions, from 5800A - 6500A, which lie within the resolution of the apparatus have been studied. The molecules are excited with a lowpower narrow band counterpropagating cw dye laser beam and two-photon fluorescence. The fluorescence intensities of many of these transitions are greater than the 3S to 5S and 3S to 4D atomic signals, where the 3P enhancing state lies 300 cm -1 from resonance. By comparing the number density of the atomic with any molecular ground state and also the two-photon transition rates to excited states, the intermediate enhancing state for a two-photon transition in Na 2 can be predicted to be less than 1 cm -1 from resonance with the two-photon transition. This observation, along with published Dunham coefficients, is used to identify the states involved in the two-photon transitions

  12. On the coupling between molecular diffusion and solvation shell exchange

    DEFF Research Database (Denmark)

    Møller, Klaus Braagaard; Rey, Rossend; Masia, Marco

    2005-01-01

    The connection between diffusion and solvent exchanges between first and second solvation shells is studied by means of molecular dynamics simulations and analytic calculations, with detailed illustrations for water exchange for the Li+ and Na+ ions, and for liquid argon. First, two methods...

  13. Meltability in system of K2TaF7-NaF-NaCl-KCl

    International Nuclear Information System (INIS)

    Kartsev, V.E.; Kovalev, F.V.; Korshunov, B.G.

    1975-01-01

    Thermographic and visual-polythermal techniques were used to study the meltability in K 2 TaF 7 -NaF-NaCl-KCl system. The tetrahedron-forming sections NaF-NaCl-K 2 TaF 7 xKCl and NaF-K 2 TaF 7 xKCl-2K 2 TaF 7 xNaCl divide the concentration tetrahedron into three particular tetrahedra: NaF-K 2 TaF 7 xKCl-2K 2 TaF 7 xNaCl-K 2 TaF 7 , NaF-NaCl-K 2 TaF 7 xKCl-2K 2 TaF 7 xaCl, and NaF-NaCl-KCl-K 2 TaF 7 xKCl. Non-variant equilibrium points in all of the particular four-component systems have been determined

  14. NA60 frees the quarks

    CERN Multimedia

    2003-01-01

    Fitted with new state-of-the-art silicon detectors, NA60 is prepared to study the phase transition from confined hadronic matter to a deconfined (free) quark-gluon plasma, a state of matter which probably existed an instant after the Big Bang.

  15. NA61/SHINE ion program

    CERN Document Server

    Mackowiak, Maja

    2010-01-01

    The Super Proton Synchrotron (SPS) at CERN covers one of the most interesting regions of the phase diagram (T - \\mu_{B}) of strongly interacting matter. The study of central Pb+Pb collisions by NA49 indicate that the threshold for deconfinement is reached already at the low SPS energies. Theoretical considerations predict a critical point of strongly interacting matter at energies accessible at the SPS. The NA61/SHINE experiment, a successor of the NA49 project, will study hadron production in p+p, p+A, h+A, and A+A reactions at various energies. The broad physics program includes the investigation of the properties of strongly interacting matter, as well as precision measurements of hadron spectra for the T2K neutrino experiment and for the Pierre Auger Observatory and KASCADE cosmic-ray projects. The main physics goals of the NA61/SHINE ion program are to study the properties of the onset of deconfinement at low SPS energies and to find signatures of the critical point of strongly interacting matter. To ach...

  16. NA62: Hidden Sector Physics

    CERN Document Server

    Cesarotti, Carissa Joyce

    2016-01-01

    Modern experimental physics is often probing for new physics by either finding deviations from predictions on extremely precise measurements, or by looking for a new signal that cannot be explained with existing models. The NA62 experiment at CERN does the former by measuring the ultra-rare decay $K^+ \\rightarrow \\pi^+ \

  17. The system NaVO3-Na2WO4-Na2W2O7

    International Nuclear Information System (INIS)

    Kazanbekov, V.R.; Gasanaliev, A.M.; Kazanbekov, R.G.

    1994-01-01

    Phase diagrams of sodium metavanadate-sodium ditungstate, sodium metavanadate-sodium tungstate systems and surface of primary crystallization of sodium metavabadate-sodium tungstate-sodium ditungstate system were studied. The system sodium metavanadate-sodium ditungstate is eutectic one. Compound NaVO 3 x2Na 2 WO 4 is formed in solid state in sodium metavanadate-sodium tungstate system. Liquidus surface of sodium metavanadate-sodium tungstate-sodium ditungstate is presented by three crystallization fields of initial components. Composition and melting point of ternary eutectics are determined

  18. Conformational Dynamics on the Extracellular Side of LeuT Controlled by Na+ and K+ Ions and the Protonation State of Glu(290)

    DEFF Research Database (Denmark)

    Khelashvili, George; Schmidt, Solveig Gaarde; Shi, Lei

    2016-01-01

    Na+ ions and substrate have left, and the transporter prepares for a new cycle. We compare the results with the consequences of binding Na+ in the same apo system. Analysis of >50-μs atomistic molecular dynamics and enhanced sampling trajectories of constructs with Glu290, either charged or neutral......Ions play key mechanistic roles in the gating dynamics of neurotransmitter:sodium symporters (NSSs). In recent microsecond scale molecular dynamics simulations of a complete model of the dopamine transporter, a NSS protein, we observed a partitioning of K+ ions from the intracellular side toward...... the unoccupied Na2 site of dopamine transporter following the release of the Na2-bound Na+. Here we evaluate with computational simulations and experimental measurements of ion affinities under corresponding conditions, the consequences of K+ binding in the Na2 site of LeuT, a bacterial homolog of NSS, when both...

  19. Europlanet NA2 Science Networking

    Science.gov (United States)

    Harri, Ari-Matti; Szego, Karoly; Genzer, Maria; Schmidt, Walter; Krupp, Norbert; Lammer, Helmut; Kallio, Esa; Haukka, Harri

    2013-04-01

    Europlanet RI / NA2 Science Networking [1] focused on determining the major goals of current and future European planetary science, relating them to the Research Infrastructure that the Europlanet RI project [2] developed, and placing them in a more global context. NA2 also enhanced the ability of European planetary scientists to participate on the global scene with their own agenda-setting projects and ideas. The Networking Activity NA2 included five working groups, aimed at identifying key science issues and producing reference books on major science themes that will bridge the gap between the results of present and past missions and the scientific preparation of the future ones. Within the Europlanet RI project (2009-2012) the NA2 and NA2-WGs organized thematic workshops, an expert exchange program and training groups to improve the scientific impact of this Infrastructure. The principal tasks addressed by NA2 were: • Science activities in support to the optimal use of data from past and present space missions, involving the broad planetary science community beyond the "space club" • Science activities in support to the preparation of future planetary missions: Earth-based preparatory observations, laboratory studies, R&D on advanced instrumentation and exploration technologies for the future, theory and modeling etc. • Develop scientific activities, joint publications, dedicated meetings, tools and services, education activities, engaging the public and industries • Update science themes and addressing the two main scientific objectives • Prepare and support workshops of the International Space Science Institute (ISSI) in Bern and • Support Trans National Activities (TNAs), Joined Research Activities (JRAs) and the Integrated and Distributed Information Service (IDIS) of the Europlanet project These tasks were achieved by WG workshops organized by the NA2 working groups, by ISSI workshops and by an Expert Exchange Program. There were 17 official WG

  20. Molecular sensors and molecular logic gates

    International Nuclear Information System (INIS)

    Georgiev, N.; Bojinov, V.

    2013-01-01

    Full text: The rapid grow of nanotechnology field extended the concept of a macroscopic device to the molecular level. Because of this reason the design and synthesis of (supra)-molecular species capable of mimicking the functions of macroscopic devices are currently of great interest. Molecular devices operate via electronic and/or nuclear rearrangements and, like macroscopic devices, need energy to operate and communicate between their elements. The energy needed to make a device work can be supplied as chemical energy, electrical energy, or light. Luminescence is one of the most useful techniques to monitor the operation of molecular-level devices. This fact determinates the synthesis of novel fluorescence compounds as a considerable and inseparable part of nanoscience development. Further miniaturization of semiconductors in electronic field reaches their limit. Therefore the design and construction of molecular systems capable of performing complex logic functions is of great scientific interest now. In semiconductor devices the logic gates work using binary logic, where the signals are encoded as 0 and 1 (low and high current). This process is executable on molecular level by several ways, but the most common are based on the optical properties of the molecule switches encoding the low and high concentrations of the input guest molecules and the output fluorescent intensities with binary 0 and 1 respectively. The first proposal to execute logic operations at the molecular level was made in 1988, but the field developed only five years later when the analogy between molecular switches and logic gates was experimentally demonstrated by de Silva. There are seven basic logic gates: AND, OR, XOR, NOT, NAND, NOR and XNOR and all of them were achieved by molecules, the fluorescence switching as well. key words: fluorescence, molecular sensors, molecular logic gates

  1. Pozitivni in negativni vplivi risank na otroke

    OpenAIRE

    Povše, Nika

    2017-01-01

    V tej diplomski nalogi smo raziskovali pozitivne in negativne vplive risank na otroke. Začeli smo z zgodovino televizije, tako svetovno zgodovino kot zgodovino televizije na Slovenskem. Na isti način smo pregledali tudi zgodovino risank. Raziskovali smo otrokov razvoj, predvsem tiste vidike, ki so izpostavljeni vplivom risank, kot so morala, jezik, domišljija in učenje. Sledilo je raziskovanje negativnih in pozitivnih vplivov, ki jih imajo risanke na otroke, kar je tudi naš glavni problem te ...

  2. Spectroscopy of Na-18: Bridging the two-proton radioactivity of Mg-19

    Czech Academy of Sciences Publication Activity Database

    Assie, M.; de Oliveira Santos, F.; Achouri, L.; Angelique, J. C.; Borcea, C.; Borcea, R.; Caceres, L.; Chudoba, V.; Pang, D. Y.; Ducoin, D.; Fallot, M.; Kamalou, O.; Kiener, J.; Lam, Y.; Lefevre, A.; Lotay, G.; Mrázek, Jaromír; Perrot, L.; Sánchez, A.; Rotaru, F.

    2012-01-01

    Roč. 712, č. 3 (2012), s. 198-202 ISSN 0370-2693 Grant - others:European Commission(XE) RII3-CT-2004-506065 Institutional support: RVO:61389005 Keywords : two-proton radioactivity * resonant elastic scattering * (19)mg * Na-18 * Ne-17 Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 4.569, year: 2012

  3. Neurological disease mutations compromise a C-terminal ion pathway in the Na(+)/K(+)-ATPas

    DEFF Research Database (Denmark)

    Poulsen, Hanne; Khandelia, Himanshu; Morth, Jens Preben

    2010-01-01

    severe neurological diseases. This novel model for ion transport by the Na(+)/K(+)-ATPase is established by electrophysiological studies of C-terminal mutations in familial hemiplegic migraine 2 (FHM2) and is further substantiated by molecular dynamics simulations. A similar ion regulation is likely...

  4. Neurological disease mutations compromise a C-terminal ion pathway in the Na(+)/K(+)-ATPase

    DEFF Research Database (Denmark)

    Poulsen, Hanne; Khandelia, Himanshu; Morth, J Preben

    2010-01-01

    severe neurological diseases. This novel model for ion transport by the Na(+)/K(+)-ATPase is established by electrophysiological studies of C-terminal mutations in familial hemiplegic migraine 2 (FHM2) and is further substantiated by molecular dynamics simulations. A similar ion regulation is likely...

  5. Over-expression of Arabidopsis DnaJ (Hsp40) contributes to NaCl ...

    African Journals Online (AJOL)

    Over-expression of Arabidopsis DnaJ (Hsp40) contributes to NaCl-stress tolerance. Z Zhichang, Z Wanrong, Y Jinping, Z Jianjun, LZL Xufeng, Y Yang. Abstract. DnaJ (Hsp40), a heat shock protein, is a molecular chaperones responsive to various environmental stress. To analyze the protective role of DnaJ, we obtained ...

  6. A study of the excited 1Σ+sub(g) states in Na2

    International Nuclear Information System (INIS)

    Taylor, A.J.; Jones, K.M.; Schawlow, A.L.

    1981-01-01

    Using the technique of two-step polarization labeling spectroscopy seven excited 1 Σ + sub(g) states in Na 2 have been found. Molecular constants are derived from a Dunham expansion. Tentative assignments are made to the 3p + 3p, 3s + nd and 3s + ns atomic asymptotes. (orig.)

  7. Alterações moleculares no Mieloma Múltiplo Molecular abnormalities in Multiple Myeloma

    Directory of Open Access Journals (Sweden)

    Esteban Braggio

    2007-03-01

    Full Text Available Nos últimos anos tem acontecido uma revolução no conhecimento dos mecanismos moleculares envolvidos na patogênese do mieloma múltiplo, principalmente devido à incorporação de técnicas de citogenética molecular (hibridização in situ fluorescente - FISH e biologia molecular (Reação em cadeia da polimerase - PCR, hibridização genômica comparativa baseada em microarranjos - aCGH e microarranjos de RNA. Estas técnicas permitem estudar as células em interfase e detectar alterações cromossômicas crípticas, superando assim problemas metodológicos relacionados à análise por citogenética convencional. Por outro lado, a complexidade metodológica relacionada com a realização das técnicas de FISH e biologia molecular tem impossibilitado que sejam amplamente utilizadas na rotina laboratorial. Este trabalho tem como objetivo fazer uma revisão das principais vias moleculares alteradas no mieloma múltiplo, o seu valor prognóstico e a sua utilização na estratificação dos pacientes em diferentes grupos de risco. São detalhadas diferentes abordagens metodológicas e uma ênfase especial é dada em relação à importância da análise se restringir exclusivamente às células plasmocitárias. Por último, discutimos uma série de prioridades e estratégias de estudo na rotina laboratorial.In recent years, we have seen an explosion in knowledge on genetic and cytogenetic mechanisms involved in the pathogenesis of multiple myeloma, mainly due to the incorporation of molecular tools in its study (fluorescence in situ hybridization - FISH, Real time PCR and RNA microarrays. These tools have enabled the study of cells in interphase and to detect cryptic chromosomal abnormalities, replacing cytogenetic techniques. The technical complexities associated with the performance of these tests, however, have limited their widespread applicability in routine clinical practice. The aim of this work is to review the present status of our

  8. Functional interaction of nicotinic acetylcholine receptors and Na+/K+ ATPase from Locusta migratoria manilensis (Meyen).

    Science.gov (United States)

    Bao, Haibo; Sun, Huahua; Xiao, Youxin; Zhang, Yixi; Wang, Xin; Xu, Xiaoyong; Liu, Zewen; Fang, Jichao; Li, Zhong

    2015-03-06

    Associated proteins are important for the correct functioning of nicotinic acetylcholine receptors (nAChRs). In the present study, a neonicotinoid-agarose affinity column was used to isolate related proteins from a solubilized membrane preparation from the nervous system of Locusta migratoria manilensis (Meyen). 1530 peptides were identified and most of them were involved in the membranous structure, molecular interaction and cellular communication. Among these peptides, Na(+)/K(+) ATPase had the highest MASCOT score and were involved in the molecular interaction, which suggested that Na(+)/K(+) ATPase and nAChRs might have strong and stable interactions in insect central nervous system. In the present study, functional interactions between nAChRs and Na(+)/K(+) ATPase were examined by heterologous expression in Xenopus oocytes. The results showed that the activated nAChRs increased pump currents of Na(+)/K(+) ATPase, which did not require current flow through open nAChRs. In turn, Na(+)/K(+) ATPase significantly increased agonist sensitivities of nAChRs in a pump activity-independent manner and reduced the maximum current (Imax) of nAChRs. These findings provide novel insights concerning the functional interactions between insect nAChRs and Na(+)/K(+) ATPase.

  9. Aspectos moleculares da anemia falciforme

    Directory of Open Access Journals (Sweden)

    Galiza Neto Gentil Claudino de

    2003-01-01

    Full Text Available No presente artigo abordaram-se vários aspectos relacionados à natureza molecular da anemia falciforme, desordem hematológica de caráter hereditário que acomete expressivo número de indivíduos em várias regiões do mundo. As pesquisas realizadas em torno desta patologia da hemácia, ao longo de quase um século, a partir de 1910, cooperaram para a criação de um novo e importante segmento da ciência, denominado biologia molecular. A descoberta dos polimorfismos da mutação (GAT->GTG no gene que codifica a cadeia beta da hemoglobina, originando diferentes haplótipos da doença, permitiu um melhor e mais amplo conhecimento em torno da heterogeneidade clínica nos pacientes falcêmicos. Analisando a hemoglobina na sua estrutura normal e mutante, sua produção e evolução, pode-se ter um entendimento mais completo da fisiopatologia desta doença e da sua complexidade clínica.

  10. Reactivity of the cyanometalate Na[Cp[prime]Mn(CO)[sub 2]CN] with titanium, zirconium, and hafnium halides. Crystal and molecular structure of the [mu]-cyano [mu]-oxo tetranuclear complex [Cp[sub 2]Zr([mu]-NC)MnCp[prime]-(CO)[sub 2

    Energy Technology Data Exchange (ETDEWEB)

    Braunstein, P. (Universite Louis Pasteur, Cedex (France)); Cauzzi, D. (Universite Louis Pasteur, Cedex (France) Universita di Parma (Italy)); Kelly, D. (Universite Louis Pasteur, Cedex (France)); Lanfranchi, M.; Tiripicchio, A. (Universita di Parma (Italy))

    1993-07-21

    In contrast to most carbonylmetalates of the transition metals, cyanide-substituted anionic complexes such as Na[Cp[prime]Mn-(CO)[sub 2]CN] (Cp[prime] = [eta]-MeC[sub 5]H[sub 4]) do not exhibit a metal-centered HOMO. Instead, this orbitals is essentially nitrogen-based, which favors coordination to metal centers through the cyanide moiety, thus generating Mn-CN-M[prime] chain systems. The cyanometalate ligand [Cp[prime]Mn(CO)[sub 2]CN][sup [minus

  11. Multichannel modeling and two-photon coherent transfer paths in NaK

    Science.gov (United States)

    Schulze, T. A.; Temelkov, I. I.; Gempel, M. W.; Hartmann, T.; Knöckel, H.; Ospelkaus, S.; Tiemann, E.

    2013-08-01

    We explore possible pathways for the creation of ultracold polar NaK molecules in their absolute electronic and rovibrational ground state starting from ultracold Feshbach molecules. In particular, we present a multichannel analysis of the electronic ground and K(4p)+Na(3s) excited-state manifold of NaK, analyze the spin character of both the Feshbach molecular state and the electronically excited intermediate states and discuss possible coherent two-photon transfer paths from Feshbach molecules to rovibronic ground-state molecules. The theoretical study is complemented by the demonstration of stimulated Raman adiabatic passage from the X1Σ+(v=0) state to the a3Σ+ manifold on a molecular beam experiment.

  12. Na+-stimulated ATPase of alkaliphilic halotolerant cyanobacterium Aphanothece halophytica translocates Na+ into proteoliposomes via Na+ uniport mechanism

    Directory of Open Access Journals (Sweden)

    Soontharapirakkul Kanteera

    2010-08-01

    Full Text Available Abstract Background When cells are exposed to high salinity conditions, they develop a mechanism to extrude excess Na+ from cells to maintain the cytoplasmic Na+ concentration. Until now, the ATPase involved in Na+ transport in cyanobacteria has not been characterized. Here, the characterization of ATPase and its role in Na+ transport of alkaliphilic halotolerant Aphanothece halophytica were investigated to understand the survival mechanism of A. halophytica under high salinity conditions. Results The purified enzyme catalyzed the hydrolysis of ATP in the presence of Na+ but not K+, Li+ and Ca2+. The apparent Km values for Na+ and ATP were 2.0 and 1.2 mM, respectively. The enzyme is likely the F1F0-ATPase based on the usual subunit pattern and the protection against N,N'-dicyclohexylcarbodiimide inhibition of ATPase activity by Na+ in a pH-dependent manner. Proteoliposomes reconstituted with the purified enzyme could take up Na+ upon the addition of ATP. The apparent Km values for this uptake were 3.3 and 0.5 mM for Na+ and ATP, respectively. The mechanism of Na+ transport mediated by Na+-stimulated ATPase in A. halophytica was revealed. Using acridine orange as a probe, alkalization of the lumen of proteoliposomes reconstituted with Na+-stimulated ATPase was observed upon the addition of ATP with Na+ but not with K+, Li+ and Ca2+. The Na+- and ATP-dependent alkalization of the proteoliposome lumen was stimulated by carbonyl cyanide m - chlorophenylhydrazone (CCCP but was inhibited by a permeant anion nitrate. The proteoliposomes showed both ATPase activity and ATP-dependent Na+ uptake activity. The uptake of Na+ was enhanced by CCCP and nitrate. On the other hand, both CCCP and nitrate were shown to dissipate the preformed electric potential generated by Na+-stimulated ATPase of the proteoliposomes. Conclusion The data demonstrate that Na+-stimulated ATPase from A. halophytica, a likely member of F-type ATPase, functions as an electrogenic Na

  13. Photodesorption of Na atoms from rough Na surfaces

    DEFF Research Database (Denmark)

    Balzer, Frank; Gerlach, R.; Manson, J.R.

    1997-01-01

    We investigate the desorption of Na atoms from large Na clusters deposited on dielectric surfaces. High-resolution translational energy distributions of the desorbing atoms are determined by three independent methods, two-photon laser-induced fluorescence, as well as single-photon and resonance......-enhanced two-photon ionization techniques. Upon variation of surface temperature and for different substrates (mica vs lithium fluoride) clear non-Maxwellian time-of-flight distributions are observed with a cos θ angular dependence and most probable kinetic energies below that expected of atoms desorbing from...... atoms are scattered by surface vibrations. Recent experiments providing time constants for the decay of the optical excitations in the clusters support this model. The excellent agreement between experiment and theory indicates the importance of both absorption of the laser photons via direct excitation...

  14. Molecular determinants of voltage-gated sodium channel regulation by the Nedd4/Nedd4-like proteins

    DEFF Research Database (Denmark)

    Rougier, Jean-Sébastien; van Bemmelen, Miguel X; Bruce, M Christine

    2004-01-01

    -ubiquitin ligases of the Nedd4 family. We recently reported that cardiac Na(v)1.5 is regulated by Nedd4-2. In this study, we further investigated the molecular determinants of regulation of Na(v) proteins. When expressed in HEK-293 cells and studied using whole cell voltage clamping, the neuronal Na(v)1.2 and Na...... that Nedd4-dependent ubiquitination of Na(v) channels may represent a general mechanism regulating the excitability of neurons and myocytes via modulation of channel density at the plasma membrane....

  15. Vpliv konfucija na sodobno izobraževanje na Kitajskem

    Directory of Open Access Journals (Sweden)

    Katja Skitek

    2009-12-01

    Full Text Available Izobraževanje na Kitajskem je bilo vedno trdno povezano s Konfucijem in konfucianizmom, kar pa ni čudno, saj je bil Konfucij prvi, ki je poudarjal moč z nanja in izobraževanja. LR Kitajska je v zadnjih petdesetih letih počasi in postopoma začela uveljavljati določene spremembe v vzgojno-izobraževalni sistem. Kakšne so te spremembe in koliko nanje še vedno vpliva konfucianizem, bo osrednja tema pričujočega članka. Konfucianizem danes na Kitajskem ni preveč popularen, izobraženci pa so se razporedili v dve skupini: eni trdijo, da je njegov vpliv še vedno velik, drugi pa zatrjujejo, da nima več nobenega vpliva na sodobno življenje. Katera stran ima prav? Konfucij je v prvi vrsti poudarjal pomembnost moralnih vrednot vsakega človeka in prav moralne vrednote, za katere se je zavzemal, so še danes trdno zasidrane v kitajski kulturi. Ali je torej sploh mogoče popolnoma izriniti Konfucija iz sodobnega izobraževanja?

  16. Basic molecular spectroscopy

    CERN Document Server

    Gorry, PA

    1985-01-01

    BASIC Molecular Spectroscopy discusses the utilization of the Beginner's All-purpose Symbolic Instruction Code (BASIC) programming language in molecular spectroscopy. The book is comprised of five chapters that provide an introduction to molecular spectroscopy through programs written in BASIC. The coverage of the text includes rotational spectra, vibrational spectra, and Raman and electronic spectra. The book will be of great use to students who are currently taking a course in molecular spectroscopy.

  17. Molecular potentials and relaxation dynamics

    International Nuclear Information System (INIS)

    Karo, A.M.

    1981-01-01

    The use of empirical pseudopotentials, in evaluating interatomic potentials, provides an inexpensive and convenient method for obtaining highly accurate potential curves and permits the modeling of core-valence correlation, and the inclusion of relativistic effects when these are significant. Recent calculations of the X 1 Σ + and a 3 Σ + states of LiH, NaH, KH, RbH, and CsH and the X 2 Σ + states of their anions are discussed. Pseudopotentials, including core polarization terms, have been used to replace the core electrons, and this has been coupled with the development of compact, higly-optimized basis sets for the corresponding one- and two-electron atoms. Comparisons of the neutral potential curves with experiment and other ab initio calculations show good agreement (within 1000 cm -1 over most of the potential curves) with the difference curves being considerably more accurate. In the method of computer molecular dynamics, the force acting on each particle is the resultant of all interactions with other atoms in the neighborhood and is obtained as the derivative of an effective many-body potential. Exploiting the pseudopotential approach, in obtaining the appropriate potentials may be very fruitful in the future. In the molecular dynamics example considered here, the conventional sum-of-pairwise-interatomic-potentials (SPP) approximation is used with the potentials derived either from experimental spectroscopic data or from Hartree-Fock calculations. The problem is the collisional de-excitation of vibrationally excited molecular hydrogen at an Fe surface. The calculations have been carried out for an initial vibrotational state v = 8, J = 1 and a translational temperature corresponding to a gas temperature of 500 0 K. Different angles of approach and different initial random impact points on the surface have been selected. For any given collision with the wall, the molecule may pick up or lose vibrotatonal and translational energy

  18. Investigação da influência do processamento na dinâmica molecular de nanocompósitos de policarbonato e argila organofílica obtidos via intercalação por fusão

    Directory of Open Access Journals (Sweden)

    Elton J. da R. Rodrigues

    Full Text Available Nanocompósitos baseados em policarbonato e argila organofílica foram obtidos pelo método de intercalação por fusão em câmara de mistura sob diferentes valores de torque e temperatura. A influência desses parâmetros na qualidade da dispersão da argila na matriz polimérica foi investigada por ressonância magnética nuclear (RMN de baixo campo, empregando o tempo de relaxação longitudinal, T1H, e por difração de raios X. As diferenças nos tempos de relaxação longitudinal e nos padrões de difração de raios X foram correlacionadas com a formação de domínios com mobilidades distintas. O nanomaterial formado apresentou morfologia intercalada com afastamento crescente das camadas de argila, conforme as condições de processamento se tornavam mais severas. A RMN ¹H mostrou que tanto o cisalhamento quanto a temperatura afetaram a mobilidade das cadeias poliméricas, explicitando a homogeneidade crescente da distribuição dos domínios de relaxação, de acordo com o aumento do torque e da temperatura.

  19. Nonadiabatic ionic--covalent transitions. Exponential-linear model for the charge exchange and neutralization reactions Na+H arrow-right-left Na++H-

    International Nuclear Information System (INIS)

    Errea, L.F.; Mendez, L.; Mo, O.; Riera, A.

    1986-01-01

    A previous study of charge exchange processes taking place through ionic--covalent transitions is extended to the case of Na+H and Na + +H - collisions. A five-state molecular expansion, with the inclusion of two-electron translation factors, is employed to calculate the charge exchange and neutralization cross sections. Transitions at the first two pseudocrossings between the energy curves, practically determine the cross sections in the energy range 0.16--5 keV amu -1 . We also show that the widely used multichannel Landau--Zener theory is totally inadequate, to treat these transitions

  20. Perinatal Na+ Overload Programs Raised Renal Proximal Na+ Transport and Enalapril-Sensitive Alterations of Ang II Signaling Pathways during Adulthood

    Science.gov (United States)

    Cabral, Edjair V.; Vieira-Filho, Leucio D.; Silva, Paulo A.; Nascimento, Williams S.; Aires, Regina S.; Oliveira, Fabiana S. T.; Luzardo, Ricardo; Vieyra, Adalberto; Paixão, Ana D. O.

    2012-01-01

    Background High Na+ intake is a reality in nowadays and is frequently accompanied by renal and cardiovascular alterations. In this study, renal mechanisms underlying perinatal Na+ overload-programmed alterations in Na+ transporters and the renin/angiotensin system (RAS) were investigated, together with effects of short-term treatment with enalapril in terms of reprogramming molecular alterations in kidney. Methodology/Principal Findings Male adult Wistar rats were obtained from dams maintained throughout pregnancy and lactation on a standard diet and drinking water (control) or 0.17 M NaCl (saline group). Enalapril (100 mg/l), an angiotensin converting enzyme inhibitor, was administered for three weeks after weaning. Ninety day old offspring from dams that drank saline presented with proximal tubules exhibiting increased (Na++K+)ATPase expression and activity. Ouabain-insensitive Na+-ATPase activity remained unchanged but its response to angiotensin II (Ang II) was lost. PKC, PKA, renal thiobarbituric acid reactive substances (TBARS), macrophage infiltration and collagen deposition markedly increased, and AT2 receptor expression decreased while AT1 expression was unaltered. Early treatment with enalapril reduced expression and activity of (Na++K+)ATPase, partially recovered the response of Na+-ATPase to Ang II, and reduced PKC and PKA activities independently of whether offspring were exposed to high perinatal Na+ or not. In addition, treatment with enalapril per se reduced AT2 receptor expression, and increased TBARS, macrophage infiltration and collagen deposition. The perinatally Na+-overloaded offspring presented high numbers of Ang II-positive cortical cells, and significantly lower circulating Ang I, indicating that programming/reprogramming impacted systemic and local RAS. Conclusions/Significance Maternal Na+ overload programmed alterations in renal Na+ transporters and in its regulation, as well as severe structural lesions in adult offspring. Enalapril

  1. Digitotalar dysmorphism: Molecular elucidation

    African Journals Online (AJOL)

    obtained for molecular studies. Since the distal arthrogryposes (DAs) are genetically heterogeneous, an unbiased approach to mutation ... Diseases and Molecular Medicine, Department of Pathology, Faculty of Health Sciences, University of Cape Town, South Africa, with an interest in molecular genetics of connective ...

  2. Artificial molecular motors

    NARCIS (Netherlands)

    Kassem, Salma; van Leeuwen, Thomas; Lubbe, Anouk S.; Wilson, Miriam R.; Feringa, Ben L.; Leigh, David A.

    2017-01-01

    Motor proteins are nature's solution for directing movement at the molecular level. The field of artificial molecular motors takes inspiration from these tiny but powerful machines. Although directional motion on the nanoscale performed by synthetic molecular machines is a relatively new

  3. Isolation, crystallization and crystal structure determination of bovine kidney Na(+),K(+)-ATPase.

    Science.gov (United States)

    Gregersen, Jonas Lindholt; Mattle, Daniel; Fedosova, Natalya U; Nissen, Poul; Reinhard, Linda

    2016-04-01

    Na(+),K(+)-ATPase is responsible for the transport of Na(+) and K(+) across the plasma membrane in animal cells, thereby sustaining vital electrochemical gradients that energize channels and secondary transporters. The crystal structure of Na(+),K(+)-ATPase has previously been elucidated using the enzyme from native sources such as porcine kidney and shark rectal gland. Here, the isolation, crystallization and first structure determination of bovine kidney Na(+),K(+)-ATPase in a high-affinity E2-BeF3(-)-ouabain complex with bound magnesium are described. Crystals belonging to the orthorhombic space group C2221 with one molecule in the asymmetric unit exhibited anisotropic diffraction to a resolution of 3.7 Å with full completeness to a resolution of 4.2 Å. The structure was determined by molecular replacement, revealing unbiased electron-density features for bound BeF3(-), ouabain and Mg(2+) ions.

  4. Tuning of the Na,K-ATPase by the beta subunit

    DEFF Research Database (Denmark)

    Hilbers, Florian; Kopec, Wojciech; Isaksen, Toke Jost

    2016-01-01

    The vital gradients of Na(+) and K(+) across the plasma membrane of animal cells are maintained by the Na,K-ATPase, an αβ enzyme complex, whose α subunit carries out the ion transport and ATP hydrolysis. The specific roles of the β subunit isoforms are less clear, though β2 is essential for motor...... to the cerebellar Na(+) and K(+) gradients....... physiology in mammals. Here, we show that compared to β1 and β3, β2 stabilizes the Na(+)-occluded E1P state relative to the outward-open E2P state, and that the effect is mediated by its transmembrane domain. Molecular dynamics simulations further demonstrate that the tilt angle of the β transmembrane helix...

  5. Novel aspects of Na+,K+-ATPase

    OpenAIRE

    Aizman, Oleg

    2002-01-01

    Na,K-ATPase, an integral membrane protein expressed in each eukaryotic cell, serves as the major determinant of intracellular ion composition. In the current study we investigated novel aspects of Na,K-ATPase function and regulation. It is well established that Na,K-ATPase activity is regulated by reversible phosphorylation. New findings in this study are: 1) the level of intracellular Ca 2. concentration determines the functional effects of PKA and PKC-mediated Na,K-ATP...

  6. Molecular computing origins and promises

    CERN Document Server

    Rambidi, Nicholas G

    2014-01-01

    Molecular Computing explores whether molecular primitives can prove to be real alternatives to contemporary semiconductor means. The text discusses molecular primitives and circuitry for information processing devices.

  7. NA64 Status Report 2018

    CERN Document Server

    Gninenko, Sergei

    2018-01-01

    The experiment NA64 is aimed at a search for a sub-GeV vector mediator (called dark photon A′) of Dark Matter production at the CERN SPS. . The main goal in 2017 was to probe a region of the A′ parameter space of the thermal dark matter model. Ongoing activities on the detector and data analysis are reviewed. The status and results from the NA64 runs in 2016 and 2017 are reported. First results on the search for the X->e+e− decay of a 17 MeV X boson, which could explain the recently observed excess of e+e-pairs from the excited 8Be nucleus transitions, and A'-> e+e- decays are also presented. Ongoing analysis on the decays of axion-like particles and plans for further searches beyond LS2 are also discussed.

  8. Makosa Yanayofanywa na Wanafunzi Wanaojifunza Kiswahili kama ...

    African Journals Online (AJOL)

    Makala haya, yanashughulika na makosa ambayo hufanywa na wanafunzi wanaojifunza Kiswahili kama lugha ya pili katika shule za sekondari nchini Uganda. Mtafiti ameyaainisha makosa mbalimbali na kuyaeleza kiusahihi. Makala yanaeleza namna ambavyo makosa hayo hutokea. Yaani, kama ni makosa ...

  9. A sol-gel based molecular imprint incorporating carbon dots for fluorometric determination of nicotinic acid

    International Nuclear Information System (INIS)

    Zuo, Pengli; Gao, Junfa; Liu, Jianha; Zhao, Mingming; Zhao, Jiahong; Peng, Jun; Zuo, Pengjian; He, Hua

    2016-01-01

    We are introducing functionalized carbon dots (C-dots) coated with a shell of molecularly imprinted sol-gel as a new tool in molecular imprint-based detection. Specifically, an imprint recognizing nicotinic acid (NA) was prepared in two steps. The first involves pyrolytic decomposition of citric acid in the presence of aminopropyltriethoxysilane to yield triethoxysilyl-modified C-dots with a typical size of 2.8 ± 1.1 nm. These are then polycondensed in the presence of tetraethoxysilane and NA at room temperature to give spherical silica nanoparticles (SiNPs) with a typical size of ∼300 nm and containing C-dots and NA in the silica matrix. NA was then removed by extraction. The resulting SiNPs are well permeable to NA, photostable, display strong blue luminescence and can bind NA fairly selectively. The fluorometric detection scheme is based on the finding that increasing concentrations of NA quench the fluorescence of the C-dots in the SiNPs. NA can be determined by this method in the 0.5 to 10.5 μM concentration range, with a 12.6 nM detection limit. The composite was successfully utilized as a fluorescent probe for the determination of NA in spiked human urine samples. The method is believed to have a wider scope in being applicable to other analytes that are capable of quenching the fluorescence of C-dots. (author)

  10. Investigations on the interactions of diclofenac sodium with HSA and ctDNA using molecular modeling and multispectroscopic methods

    Science.gov (United States)

    Cui, Yanrui; Hao, Erjun; Hui, Guangquan; Guo, Wei; Cui, Fengling

    2013-06-01

    A tentative study on interaction of diclofenac sodium (DF-Na) with human serum albumin (HSA) and calf thymus DNA (ctDNA) was conducted by using multi-spectroscopic and molecular modeling techniques under simulative physiological conditions. The results of spectroscopic measurements suggested that the quenching mechanisms were static quenching. Three-dimensional fluorescence spectroscopy clearly demonstrated the occurrence of conformational changes of HSA with addition of DF-Na. In addition, competitive studies with ethidium bromide (EB) have shown that DF-Na can bind to ctDNA relatively strong via groove binding. Based on the values of thermodynamic parameters and the results of molecular modeling, it was confirmed that hydrophobic forces and hydrogen bond were the mainly binding forces in DF-Na-HSA and DF-Na-DNA systems. The binding distance between DF-Na and HSA was also determined using the theory of the Förster energy transference.

  11. Molecular similarity measures.

    Science.gov (United States)

    Maggiora, Gerald M; Shanmugasundaram, Veerabahu

    2011-01-01

    Molecular similarity is a pervasive concept in chemistry. It is essential to many aspects of chemical reasoning and analysis and is perhaps the fundamental assumption underlying medicinal chemistry. Dissimilarity, the complement of similarity, also plays a major role in a growing number of applications of molecular diversity in combinatorial chemistry, high-throughput screening, and related fields. How molecular information is represented, called the representation problem, is important to the type of molecular similarity analysis (MSA) that can be carried out in any given situation. In this work, four types of mathematical structure are used to represent molecular information: sets, graphs, vectors, and functions. Molecular similarity is a pairwise relationship that induces structure into sets of molecules, giving rise to the concept of chemical space. Although all three concepts - molecular similarity, molecular representation, and chemical space - are treated in this chapter, the emphasis is on molecular similarity measures. Similarity measures, also called similarity coefficients or indices, are functions that map pairs of compatible molecular representations that are of the same mathematical form into real numbers usually, but not always, lying on the unit interval. This chapter presents a somewhat pedagogical discussion of many types of molecular similarity measures, their strengths and limitations, and their relationship to one another. An expanded account of the material on chemical spaces presented in the first edition of this book is also provided. It includes a discussion of the topography of activity landscapes and the role that activity cliffs in these landscapes play in structure-activity studies.

  12. Pseudo-ternary phase diagram in the Na2O-Na2O2-NaOH system

    International Nuclear Information System (INIS)

    Saito, Jun-ichi; Tendo, Masayuki; Aoto, Kazumi

    1997-10-01

    Generally, the phase diagrams are always used to understand the present state of compounds at certain temperature. In order to understand the corrosion behavior of structural material for FBR by main sodium compounds (Na 2 O, Na 2 O 2 and NaOH), it is very important to comprehend the phase diagrams of their compounds. However, only Na 2 O-NaOH pseudo-binary phase diagram had been investigated previously in this system. There is no study of other pseudo-binary or ternary phase diagrams in the Na 2 O-Na 2 O 2 -NaOH system. In this study, in order to clarify the present states of their compounds at certain temperatures, the pseudo-binary and ternary phase diagrams in the Na 2 O-Na 2 O 2 -NaOH system were prepared. A series of thermal analyses with binary and ternary component system has been carried out using the differential scanning calorimetry (DSC). The liquidus temperature and ternary eutectic temperatures were confirmed by these measurements. The beneficial indications for constructing phase diagrams were obtained from these experiments. On the basis of these results, the interaction parameters between compounds which were utilized for the Thermo-Calc calculation were optimized. Thermo-Calc is one of thermodynamic calculation software. Consequently the accurate pseudo-binary and ternary phase diagrams were indicated using the optimized parameters. (author)

  13. Na+,K+-ATPase Na+ affinity in rat skeletal muscle fiber types

    DEFF Research Database (Denmark)

    Kristensen, Michael; Juel, Carsten

    2010-01-01

    Previous studies in expression systems have found different ion activation of the Na(+)/K(+)-ATPase isozymes, which suggest that different muscles have different ion affinities. The rate of ATP hydrolysis was used to quantify Na(+),K(+)-ATPase activity, and the Na(+) affinity of Na(+),K(+)-ATPase...

  14. Expression of Insoluble Influenza Neuraminidase Type 1 (NA1 Protein in Tobacco

    Directory of Open Access Journals (Sweden)

    Teen Lee Pua

    2012-12-01

    Full Text Available The avian influenza virus, particularly H5N1 strain, is highly virulent to poultry and mankind. Several expression systems, like yeast, baculovirus and mammalian cells, have been adopted to produce vaccine candidate for this lethal disease. The present research aimed at developing a recombinant vaccine candidate, neuraminidase type 1 (NA1, for the Malaysia isolate of H5N1 in Nicotiana benthamiana. The NA1 gene was fused directly in-frame in cowpea mosaic virus (CPMV-based pEAQ-HT vector with C-terminal polyhistidine-tag incorporated to ease the subsequent purification step. The expression of the NA1 gene in tobacco was confirmed at RNA and protein levels at 6 days post-infiltration (Dpi. From the insoluble fraction of the protein, a recombinant glycosylated NA1 protein with a molecular weight of ~56 kDa was immunogenically detected by a specific anti-NA polyclonal antibody. We report for the first time the insolubility of the plant-made NA1 protein where a native sequence was used for its expression. This study signifies the necessity of the use of optimised sequences for expression work and provides great opportunity for the exploration of plant-manufactured NA1 protein as vaccine candidate.

  15. Homocisteína Homocysteine

    Directory of Open Access Journals (Sweden)

    Lindalva Batista Neves

    2004-10-01

    Full Text Available A homocisteína, formada a partir da metionina hepática, é metabolizada nas vias de desmetilação e de transulfuração, sendo que seus valores plasmáticos e urinários refletem a síntese celular. Sua determinação, realizada em jejum e após sobrecarga de metionina, caracteriza as diferenças dessas vias metabólicas, principalmente quando de natureza genética. A hiper-homocisteinemia tem sido associada a maior risco de eventos aterotrombóticos, e a literatura sugere associação causal, independente de outros fatores de risco para doença arterial. Diminuição da homocisteína plasmática para valores normais é seguida de redução significante na incidência de doença aterotrombótica. A relação entre homocisteína e o fígado vem adquirindo importância nos dias atuais, uma vez que alterações das lipoproteínas e da depuração de metionina são comuns em pacientes com doença hepática crônica (hepatocelular e canalicular. O tratamento da hiper-homocisteinemia fundamenta-se na suplementação alimentar e medicamentosa de ácido fólico e vitaminas B6 e B12.Homocysteine, formed from hepatic methionine, is metabolized through the pathways of demethylation and transsulfuration. Its plasmatic and urinary values reflect the cell synthesis. Its determination after fasting and increased infusion of methionine shows the differences of these two metabolic pathways, mainly when it is related to genetic diseases. Hyperhomocysteinemia has been associated with a higher risk of vascular thrombotic events. Several authors suggest a causal relationship between these events independently of other risk factors for vascular diseases. Decrease in plasmatic homocysteine to normal levels is followed by a significant reduction on the incidence of vascular thrombotic events. The correlation between the liver and homocysteine is becoming more important because of the recent findings that alterations of lipoproteins and methionine clearance are

  16. NaCl islands decorated with 2D or 3D 3,4,9,10-perylene-tetracarboxylic-dianhydride nanostructures

    International Nuclear Information System (INIS)

    Sun Xiaonan; Silly, Fabien

    2010-01-01

    The formation of PTCDA (3,4,9,10-perylene-tetracarboxylic-dianhydride) nanostrutures on Au(1 1 1)-(22x√(3)) covered with NaCl islands has been studied using scanning tunneling microscopy (STM). Atomically resolved STM images show that NaCl grows as (1 0 0)-terminated layers on Au(1 1 1)-(22x√(3)). Local atomic hexagonal packing has also been observed in the NaCl(1 0 0) layer. At submonolayer NaCl coverage, PTCDA forms two-dimensional islands on the Au(1 1 1) surface and nucleate preferentially at the NaCl island step edges. When the Au surface is fully covered with NaCl layers, PTCDA molecules form three-dimensional molecular clusters decorating the step edges of NaCl layers.

  17. NaCl islands decorated with 2D or 3D 3,4,9,10-perylene-tetracarboxylic-dianhydride nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Sun Xiaonan [Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, NL-9747 AG Groningen (Netherlands); Silly, Fabien, E-mail: Fabien.silly@cea.fr [Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, NL-9747 AG Groningen (Netherlands); CEA, IRAMIS, SPCSI, Nanostructures and Organic Semiconductors Laboratory, F-91191 Gif-sur-Yvette (France); UPMC, IPCM, UMR CNRS 7201, 4 place Jussieu, F-75005 Paris (France)

    2010-01-15

    The formation of PTCDA (3,4,9,10-perylene-tetracarboxylic-dianhydride) nanostrutures on Au(1 1 1)-(22x{radical}(3)) covered with NaCl islands has been studied using scanning tunneling microscopy (STM). Atomically resolved STM images show that NaCl grows as (1 0 0)-terminated layers on Au(1 1 1)-(22x{radical}(3)). Local atomic hexagonal packing has also been observed in the NaCl(1 0 0) layer. At submonolayer NaCl coverage, PTCDA forms two-dimensional islands on the Au(1 1 1) surface and nucleate preferentially at the NaCl island step edges. When the Au surface is fully covered with NaCl layers, PTCDA molecules form three-dimensional molecular clusters decorating the step edges of NaCl layers.

  18. Myocardial Na,K-ATPase: Clinical aspects

    OpenAIRE

    Kjeldsen, Keld

    2003-01-01

    The specific binding of digitalis glycosides to Na,K-ATPase is used as a tool for Na,K-ATPase quantification with high accuracy and precision. In myocardial biopsies from patients with heart failure, total Na,K-ATPase concentration is decreased by around 40%; a correlation exists between a decrease in heart function and a decrease in Na,K-ATPase concentration. During digitalization, around 30% of remaining pumps are occupied by digoxin. Myocardial Na,K-ATPase is also influenced by other drugs...

  19. Crowdsourcing: impactos na performance na venda de produtos

    OpenAIRE

    Alves, Milton Ruiz Rodrigues

    2015-01-01

    Vivemos num momento em que as expectativas de pensadores como Lévy (1998), se concretizaram. O consumidor mudou, passou a exigir um diálogo entre a empresa e a sociedade. Esse novo cenário cobrou da tecnologia formas de aperfeiçoar e agilizar este processo de comunicação, plataformas baseadas na internet que propiciem e incentivam a troca de informações. Nesta esfera surgiu o crowdsourcing, com a disponibilização do capital intelectual das massas, que acabou por mudar a form...

  20. Silicene for Na-ion battery applications

    KAUST Repository

    Zhu, Jiajie

    2016-08-19

    Na-ion batteries are promising candidates to replace Li-ion batteries in large scale applications because of the advantages in natural abundance and cost of Na. Silicene has potential as the anode in Li-ion batteries but so far has not received attention with respect to Na-ion batteries. In this context, freestanding silicene, a graphene-silicene-graphene heterostructure, and a graphene-silicene superlattice are investigated for possible application in Na-ion batteries, using first-principles calculations. The calculated Na capacities of 954mAh/g for freestanding silicene and 730mAh/g for the graphenesilicene superlattice (10% biaxial tensile strain) are highly competitive and potentials of >0.3 V against the Na/Na potential exceed the corresponding value of graphite. In addition, the diffusion barriers are predicted to be <0.3 eV.

  1. Hali ya taaluma ya ukalimani Tanzania: jana, leo na kesho ...

    African Journals Online (AJOL)

    Umuhimu wa ukalimani katika mawasiliano umeongezeka kutokana na utandawazi. Utandawazi umerahisisha kukutanika na kuwasiliana kwa watu wazungumzao lugha tofauti kupitia wakalimani. Kutokana na ongezeko hilo la umuhimu wa ukalimani, kumekuwa na jitihada mbalimbali katika nchi mbalimbali kuhakikisha ...

  2. New results from NA49

    CERN Document Server

    Afanasiev, S V; Bächler, J; Barna, D; Barnby, L S; Bartke, Jerzy; Barton, R A; Behler, M; Betev, L; Bialkowska, H; Billmeier, A; Blume, C; Blyth, C O; Boimska, B; Botje, M; Bracinik, J; Brady, F P; Bramm, R; Brun, R; Buncic, P; Carr, L; Cebra, D; Cerny, V; Cooper, G E; Cramer, J G; Csató, P; Dinkelaker, P; Eckardt, V; Eckhardt, F; Ferenc, D; Filip, P; Fischer, H G; Foder, Z; Foka, P Y; Freund, P; Friese, V; Gál, J; Ganz, R E; Gazdzicki, M; Georgopoulos, G; Gladysz-Dziadus, E; Harris, J W; Hegyi, S; Höhne, C; Igo, G; Jacobs, P; Jones, P G; Kadija, K; Kolesnikov, V I; Kollegger, T; Kowalski, M; Kraus, I; Kreps, M; Lasiuk, B; Van Leeuwen, M; Lévai, Peter; Malakhov, A I; Margetis, S; Markert, C; Mayes, B W; Melkumov, G L; Mischke, A; Molnár, J; Nelson, J M; Odyniec, Grazyna Janina; Oldenburg, M; Pálla, G; Panagiotou, A D; Perl, K; Petridis, A; Pikna, M; Pinsky, L; Poskanzer, A M; Prindle, D J; Pühlhofer, F; Putschke, J; Reid, J G; Renfordt, A; Retyk, W; Ritter, H G; Röhrich, D; Roland, C; Roland, G; Rybicki, A; Sammer, T; Sann, H; Schäfer, E; Schmitz, N; Seyboth, P; Siklér, F; Sitár, B; Skrzypczak, E; Snellings, R; Squier, G T A; Stock, Reinhard; Ströbele, H; Susa, T; Szentpétery, I; Sziklai, J; Toy, M; Trainor, T A; Trentalange, S; Ullrich, T S; Varga, D; Vassiliou, Maria; Veres, G I; Vesztergombi, G; Voloshin, S A; Vranic, D; Wang, F; Weerasundara, D D; Wenig, S; Wetzler, A; Whitten, C; Xu, N; Yates, T A; Koo, I K; Zaranek, J; Zimányi, J

    2002-01-01

    Recent results of the NA49 experiment are presented. These cover first results on pion and kaon production, HBT, and charge fluctuations from Pb+Pb reactions at 40 AGeV and their comparison to 158 AGeV beam energy. Furthermore a study on baryon number transfer in p+p, centrality selected p+Pb and Pb+Pb collisions at 158 AGeV and new results on the system size dependence of kaon yields, including C+C and Si+Si data, are presented. Additionally, a first result on Lambda Lambda correlations is shown. (11 refs).

  3. Loucura imperial na Roma antiga

    Directory of Open Access Journals (Sweden)

    Aloys Winterling

    2012-06-01

    Full Text Available Este artigo aborda a questão da "loucura imperial" na Roma antiga, indagando-se sobre o que seria peculiar a ações de imperadores, como Calígula, Nero e Domiciano, que conduziu a conflitos com a aristocracia. Argumenta-se que apenas uma análise das estruturas e sistemas históricos do Alto Império possibilita explicar certos padrões de comportamento imperial, usualmente classificados como loucura pela historiografia dos séculos XIX e XX.

  4. Molecular photoionization dynamics

    International Nuclear Information System (INIS)

    Dehmer, J.L.

    1982-01-01

    This program seeks to develop both physical insight and quantitative characterization of molecular photoionization processes. Progress is briefly described, and some publications resulting from the research are listed

  5. Polymer friction Molecular Dynamics

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Samoilov, Vladimir N.; Persson, Bo N. J.

    We present molecular dynamics friction calculations for confined hydrocarbon solids with molecular lengths from 20 to 1400 carbon atoms. Two cases are considered: a) polymer sliding against a hard substrate, and b) polymer sliding on polymer. In the first setup the shear stresses are relatively...... independent of molecular length. For polymer sliding on polymer the friction is significantly larger, and dependent on the molecular chain length. In both cases, the shear stresses are proportional to the squeezing pressure and finite at zero load, indicating an adhesional contribution to the friction force....

  6. Scanning probe methods applied to molecular electronics

    Energy Technology Data Exchange (ETDEWEB)

    Pavlicek, Niko

    2013-08-01

    Scanning probe methods on insulating films offer a rich toolbox to study electronic, structural and spin properties of individual molecules. This work discusses three issues in the field of molecular and organic electronics. An STM head to be operated in high magnetic fields has been designed and built up. The STM head is very compact and rigid relying on a robust coarse approach mechanism. This will facilitate investigations of the spin properties of individual molecules in the future. Combined STM/AFM studies revealed a reversible molecular switch based on two stable configurations of DBTH molecules on ultrathin NaCl films. AFM experiments visualize the molecular structure in both states. Our experiments allowed to unambiguously determine the pathway of the switch. Finally, tunneling into and out of the frontier molecular orbitals of pentacene molecules has been investigated on different insulating films. These experiments show that the local symmetry of initial and final electron wave function are decisive for the ratio between elastic and vibration-assisted tunneling. The results can be generalized to electron transport in organic materials.

  7. The effect of Na vapor on the Na content of chondrules

    Science.gov (United States)

    Lewis, R. Dean; Lofgren, Gary E.; Franzen, Hugo F.; Windom, Kenneth E.

    1993-01-01

    Chondrules contain higher concentrations of volatiles (Na) than expected for melt droplets in the solar nebula. Recent studies have proposed that chondrules may have formed under non-canonical nebular conditions such as in particle/gas-rich clumps. Such chondrule formation areas may have contained significant Na vapor. To test the hypothesis of whether a Na-rich vapor would minimize Na volatilization reaction rates in a chondrule analog and maintain the Na value of the melt, experiments were designed where a Na-rich vapor could be maintained around the sample. A starting material with a melting point lower that typical chondrules was required to keep the logistics of working with Na volatilization from NaCl within the realm of feasibility. The Knippa basalt, a MgO-rich alkali olivine basalt with a melting temperature of 1325 +/- 5 C and a Na2O content of 3.05 wt%, was used as the chondrule analog. Experiments were conducted in a 1 atm, gas-mixing furnace with the fO2 controlled by a CO/CO2 gas mixture and fixed at the I-W buffer curve. To determine the extent of Na loss from the sample, initial experiments were conducted at high temperatures (1300 C - 1350 C) for duration of up to 72 h without a Na-rich vapor present. Almost all (up to 98%) Na was volatilized in runs of 72 h. Subsequent trials were conducted at 1330 C for 16 h in the presence of a Na-rich vapor, supplied by a NaCl-filled crucible placed in the bottom of the furnace. Succeeding Knudsen cell weight-loss mass-spectrometry analysis of NaCl determined the P(sub Na) for these experimental conditions to be in the 10(exp -6) atm range. This value is considered high for nebula conditions but is still plausible for non-canonical environments. In these trials the Na2O content of the glass was maintained or in some cases increased; Na2O values ranged from 2.62% wt to 4.37% wt. The Na content of chondrules may be controlled by the Na vapor pressure in the chondrule formation region. Most heating events capable

  8. O ATLETISMO NA PERSPECTIVA EDUCACIONAL

    Directory of Open Access Journals (Sweden)

    Leandro Araujo de Sousa

    2017-06-01

    Full Text Available A educação física escolar deve proporcionar experiências aos alunos para o seu desenvolvimento integral. As aulas muitas vezes são reduzidas ao ensino de esportes tradicionais, o que limita o repertório de movimentos dos alunos. Dessa forma o presente estudo de revisão objetiva problematizar o atletismo no ambiente escolar e propor possibilidades pedagógicas para seu ensino. Nesta pesquisa propomos tratar o ensino do atletismo na escola, caracterizando-o pelo seu repertório de movimentos que são naturais ao ser humano, como correr, saltar e lançar, o que possibilita maior praticidade em sua aplicação pedagógica, porém essas possibilidades não são consideradas no ambiente educacional. Diante dos dados encontrados, sugerimos que esse esporte seja abordado de forma multidimensional no ambiente escolar contextualizando-o à visão de algumas correntes teóricas. Nessa perspectiva do esporte educacional, o atletismo pode, assim como deve ser trabalhado nas aulas de educação física como instrumento pedagógico de ensino e auxiliar na formação do aluno de forma global.

  9. Identidades Homossexuais na Territorialidade Tradicionalista

    Directory of Open Access Journals (Sweden)

    Edipo Djavan dos Reis Göergen

    2015-12-01

    Full Text Available Este artigo apresenta o debate teórico que sustenta a pesquisa de mestrado desenvolvida pelo autor. Tendo por base suas vivências em contextos de tradicionalismo gaúcho, o autor deste trabalho tem percebido a grande quantidade de homossexuais, ou indivíduos que se auto-denominam não-heterossexuais, integrando as atividades artísticas do Movimento Tradicionalista Gaúcho, ou a territorialidade tradicionalista. Interessado em investigar tal fenômeno, o autor tem desenvolvido o projeto de pesquisa “Os Espaços Paradoxais de Relações Homoeróticas na Territorialidade Tradicionalista”, sob orientação do prof. Dr. Benhur Pinós da Costa, no Programa de Pós-Graduação em Geografia (UFSM. Para que essa pesquisa seja realizada, levam-se em conta as relações de gênero e de sexualidade que estão envolvidas no tema. Dessa forma, por ainda se tratarem de temáticas tidas como insignificantes na sociedade em geral e marginalizadas no campo científico, para que o presente trabalho fosse empreendido, buscou-se amparo teórico nas geografias feministas e queer, segmentos contemporâneos da ciência geográfica.

  10. Molecular dynamics study of the vaporization of an ionic drop.

    Science.gov (United States)

    Galamba, N

    2010-09-28

    The melting of a microcrystal in vacuum and subsequent vaporization of a drop of NaCl were studied through molecular dynamics simulations with the Born-Mayer-Huggins-Tosi-Fumi rigid-ion effective potential. The vaporization was studied for a single isochor at increasing temperatures until the drop completely vaporized, and gaseous NaCl formed. Examination of the vapor composition shows that the vapor of the ionic drop and gaseous NaCl are composed of neutral species, the most abundant of which, ranging from simple NaCl monomers (ion pairs) to nonlinear polymers, (Na(n)Cl(n))(n=2-4). The enthalpies of sublimation, vaporization, and dissociation of the different vapor species are found to be in reasonable agreement with available experimental data. The decrease of the enthalpy of vaporization of the vapor species, with the radius of the drop decrease, accounts for a larger fraction of trimers and tetramers than that inferred from experiments. Further, the rhombic dimer is significantly more abundant than its linear isomer although the latter increases with the temperature. The present results suggest that both trimers and linear dimers may be important to explain the vapor pressure of molten NaCl at temperatures above 1500 K.

  11. Relationship between intracellular Na+ concentration and reduced Na+ affinity in Na+,K+-ATPase mutants causing neurological disease

    DEFF Research Database (Denmark)

    Toustrup-Jensen, Mads Schak; Einholm, Anja P.; Schack, Vivien

    The neurological disorders familial hemiplegic migraine type 2 (FHM2), alternating hemiplegia of childhood (AHC), and rapid-onset dystonia parkinsonism (RDP) are caused by mutations of Na+,K+-ATPase α2 and α3 isoforms, expressed in glial and neuronal cells, respectively. Although these disorders......, addressing the question to what extent they cause a change of the intracellular Na+ and K+ concentrations ([Na+]i and [K+]i) in COS cells. C-terminal extension mutants generally showed dramatically reduced Na+ affinity without disturbance of K+ binding, as did other RDP mutants. No phosphorylation from ATP...

  12. Fotografia na Imprensa: conflitos na câmara escura

    Directory of Open Access Journals (Sweden)

    José Lúcio da Silva Menezes

    2014-07-01

    Full Text Available Este artigo recupera o teor ideológico do discurso que a Revista Veja elaborou sobre a classe trabalhadora que emergiu no cenário brasileiro, no final da década de 1970. O destaque dado aos trabalhadores como temática central resgatada, deve-se aos movimentos grevistas por eles encetados, após anos de ocultamento de sua resistência sob a repressão da ditadura civil-militar (1964-1985. Com a rebeldia operária, as matérias a respeito deste grupo, na Revista,foram se tornando mais constantes e visíveis, pois já não era mais possível, para a Revista Veja, ignorar a existência da classe operária que, com a força insurgente das greves, ocupava as ruas do Brasil.

  13. Uso da papaína na úlcera plantar

    OpenAIRE

    Otuka, Elizabet Shizue; Pedrazzani, Elisete Silva; Pioto, Mariangela Pedroso

    1996-01-01

    Este trabalho teve por objetivo contribuir para a diminuição da incapacidade em hanseníase e as contínuas recidivas de úceras plantares, através da utilização de um método de tratamento com o uso da papaína e ações de educação em saúde. Foi realizado em um Centro de Saúde com pacientes que apresentavam úcera plantar e que concordaram em participar do tratamento proposto. Analisando e comparando os dados obtidos antes e após o tratamento, concluímos que durante o tratamento foi observada uma m...

  14. Na and K dependence of the Na/K pump in cystic fibrosis fibroblasts.

    OpenAIRE

    Reznik, V M; Schneider, J A; Mendoza, S A

    1981-01-01

    The Na and K dependence of the Na/K pump was measured in skin fibroblasts from patients with cystic fibrosis and age/sex-matched controls. Under basal conditions, there was no difference between control and cystic fibrosis cells in protein per cell, intracellular Na and K content, or Na/K pump activity (measured as ouabain-sensitive 86Rb uptake). There was no difference in the Na dependence of the Na/K pump between cystic fibrosis cells and control cells. In cells from patients with cystic fi...

  15. Vpliv toplotnih mostov na porabo energije za ogrevanje na primeru osnovne šole

    OpenAIRE

    Megušar, Primož

    2015-01-01

    Na primeru Osnovne šole Dobrova sem preveril, kakšen vpliv imajo dejanski toplotni mostovi na porabo energije za ogrevanje. Iz načrtov stavbe sem evidentiral vse toplotne mostove, kateri vplivajo na porabo energije. Tem toplotnim mostovom sem nato v standardu SIST EN ISO 14683 poiskal ustrezne približke. Nato sem s programom TOST izvedel tri simulacije. V prvem primeru toplotnih mostov nisem upošteval. V drugem primeru sem toplotne mostove upošteval na poenostavljen način, v zadnjem primeru p...

  16. Mecanismos moleculares envolvendo a alfa-sinucleína e a sinfilina-1 na doença de Parkinson

    OpenAIRE

    Tayob, Soraya Barbosa

    2014-01-01

    Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz A doença de Parkinson (DP) é a patologia neurodegenerativa mais prevalente logo a seguir à doença de Alzheimer, afectando 1% dos indivíduos com idades superiores a 60 anos. A DP é caracterizada, clinicamente, por severos sintomas motores incluindo tremor, rigidez muscular, instabilidade postural e bradicinesia. Uma das principais características é a presença de Corpos de Lewy associada a uma p...

  17. Low-spin states of 23Na

    International Nuclear Information System (INIS)

    Bakkum, E.L.

    1987-01-01

    A study of 23 Na via the 22 Ne(p,γ) 23 Na and 23 Na(γ,γ) 23 Na reactions is presented. Only a limited number of resonances has been studied, selected on the basis of strong excitation of the lowest levels of which the spin was unknown. As a result the spins are now known of all levels of 23 Na with excitation energies up to 7 MeV, except for a few high-spin states which are too weakly excited in the decay of the known 22 Ne(p,γ) resonances. The mean lifetimes of the 23 Na levels at 4.43 and 7.89 MeV were found to be 350±70 and 220±17 attoseconds (1 attosecond = 10 -18 seconds) respectively. 97 refs.; 22 figs.; 12 tabs

  18. Making molecular machines work

    NARCIS (Netherlands)

    Browne, Wesley R.; Feringa, Ben L.

    2006-01-01

    In this review we chart recent advances in what is at once an old and very new field of endeavour the achievement of control of motion at the molecular level including solid-state and surface-mounted rotors, and its natural progression to the development of synthetic molecular machines. Besides a

  19. Veterinary Molecular Diagnostics

    NARCIS (Netherlands)

    Roest, H.I.J.; Engelsma, M.Y.; Weesendorp, E.; Bossers, A.; Elbers, A.R.W.

    2017-01-01

    In veterinary molecular diagnostics, samples originating from animals are tested. Developments in the farm animals sector and in our societal attitude towards pet animals have resulted in an increased demand for fast and reliable diagnostic techniques. Molecular diagnostics perfectly matches this

  20. Molecular Beacons in Diagnostics

    OpenAIRE

    Tyagi, Sanjay; Kramer, Fred Russell

    2012-01-01

    Recent technical advances have begun to realize the potential of molecular beacons to test for diverse infections in clinical diagnostic laboratories. These include the ability to test for, and quantify, multiple pathogens in the same clinical sample, and to detect antibiotic resistant strains within hours. The design principles of molecular beacons have also spawned a variety of allied technologies.

  1. Molecular microbial ecology manual

    NARCIS (Netherlands)

    Kowalchuk, G.A.; Bruijn, de F.J.; Head, I.M.; Akkermans, A.D.L.

    2004-01-01

    The field of microbial ecology has been revolutionized in the past two decades by the introduction of molecular methods into the toolbox of the microbial ecologist. This molecular arsenal has helped to unveil the enormity of microbial diversity across the breadth of the earth's ecosystems, and has

  2. Principles of molecular oncology

    National Research Council Canada - National Science Library

    Bronchud, Miguel H

    2008-01-01

    ...-threatening diseases. Many new molecularly targeted diagnostics and therapeutics described in this text, developed based on the rapid growth in our understanding of the molecular basis of cancer, already substantially improve survival of patients with previously lethal malignancies, and also improve quality of life because of fewer toxicities. Clearly re...

  3. Molecular Typing and Differentiation

    Science.gov (United States)

    In this chapter, general background and bench protocols are provided for a number of molecular typing techniques in common use today. Methods for the molecular typing and differentiation of microorganisms began to be widely adopted following the development of the polymerase chai...

  4. Principles of molecular oncology

    National Research Council Canada - National Science Library

    Bronchud, Miguel H; Thomas, E. Donnall; Weatherall, D. J; Crowther, D. G

    2004-01-01

    ...-threatening diseases. Many new molecularly targeted diagnostics and therapeutics described in this text, developed based on the rapid growth in our understanding of the molecular basis of cancer, already substantially improve survival of patients with previously lethal malignancies, and also improve quality of life because of fewer toxicities. Clearly re...

  5. Ionic and Molecular Liquids

    DEFF Research Database (Denmark)

    Chaban, Vitaly V.; Prezhdo, Oleg

    2013-01-01

    applications of RTILs in combination with molecular liquids, concentrating on three significant areas: (1) the use of molecular liquids to decrease the viscosity of RTILs; (2) the role of RTIL micelle formation in water and organic solvents; and (3) the ability of RTILs to adsorb pollutant gases. Current...

  6. Molecular Stirrers in Action

    NARCIS (Netherlands)

    Chen, Jiawen; Kistemaker, Jos C. M.; Robertus, Jort; Feringa, Ben L.

    2014-01-01

    A series of first-generation light-driven molecular motors with rigid substituents of varying length was synthesized to act as "molecular stirrers". Their rotary motion was studied by H-1 NMR and UV-vis absorption spectroscopy in a variety of solvents with different polarity and viscosity.

  7. Molecular subgroups of medulloblastoma

    OpenAIRE

    Northcott, Paul A; Dubuc, Adrian M; Pfister, Stefan; Taylor, Michael D

    2012-01-01

    Recent efforts at stratifying medulloblastomas based on their molecular features have revolutionized our understanding of this morbidity. Collective efforts by multiple independent groups have subdivided medulloblastoma from a single disease into four distinct molecular subgroups characterized by disparate transcriptional signatures, mutational spectra, copy number profiles and, most importantly, clinical features. We present a summary of recent studies that have contributed to our understand...

  8. PRIMERJAVA GEODETSKIH METOD NA ZAHTEVNEM GRADBENEM OBJEKTU

    OpenAIRE

    Reberčnik, Matic

    2017-01-01

    V projektni nalogi smo v uvodnih poglavjih predstavili različne načine izvajanja geodetskih meritev, ki jih v gradbeništvu uporabljamo pri analizi pomikov in deformacij gradbenih konstrukcij ter terena, na katerem so le-te postavljene. V nadaljevanju opisujemo terestične in GNSS (globalni navigacijski satelitski sistem) metode, ki smo jih uporabljali pri izvajanju meritev na izbranem premostitvenem objektu avtocestnega odseka v Sloveniji (zaradi varovanja podatkov ga imenujemo Objekt 1). Pod...

  9. Theoretical molecular biophysics

    CERN Document Server

    Scherer, Philipp O J

    2017-01-01

    This book gives an introduction to molecular biophysics. It starts from material properties at equilibrium related to polymers, dielectrics and membranes. Electronic spectra are developed for the understanding of elementary dynamic processes in photosynthesis including proton transfer and dynamics of molecular motors. Since the molecular structures of functional groups of bio-systems were resolved, it has become feasible to develop a theory based on the quantum theory and statistical physics with emphasis on the specifics of the high complexity of bio-systems. This introduction to molecular aspects of the field focuses on solvable models. Elementary biological processes provide as special challenge the presence of partial disorder in the structure which does not destroy the basic reproducibility of the processes. Apparently the elementary molecular processes are organized in a way to optimize the efficiency. Learning from nature by means exploring the relation between structure and function may even help to b...

  10. Na-ion batteries based on the inorganic BN nanocluster anodes: DFT studies.

    Science.gov (United States)

    Nejati, K; Hosseinian, A; Bekhradnia, A; Vessally, E; Edjlali, L

    2017-06-01

    It has been recently indicated that the Li-ion batteries may be replaced by Na-ion batteries because of their low safety, high cost, and low-temperature performance, and lack of the Li mineral reserves. Here, using density functional theory calculations, we studied the potential application of B 12 N 12 nanoclusters as anode in Na-ion batteries. Our calculations indicate that the adsorption energy of Na + and Na are about -23.4 and -1.4kcal/mol, respectively, and the pristine BN cage to improve suffers from a low cell voltage (∼0.92V) as an anode in Na-ion batteries. We presented a strategy to increase the cell voltage and performance of Na-ion batteries. We showed that encapsulation of different halides (X=F - , Cl - , or Br - ) into BN cage significantly increases the cell voltage. By increasing the atomic number of X, the Gibbs free energy change of cell becomes more negative and the cell voltage is increased up to 3.93V. The results are discussed based on the structural, energetic, frontier molecular orbital, charge transfer and electronic properties and compared with the performance of other nanostructured anodes. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Substrate-Na{sup +} complex formation: Coupling mechanism for {gamma}-aminobutyrate symporters

    Energy Technology Data Exchange (ETDEWEB)

    Pallo, Anna; Simon, Agnes [Department of Neurochemistry, Institute of Biomolecular Chemistry, Chemical Research Center, Hungarian Academy of Sciences (Hungary); Bencsura, Akos [Department of Theoretical Chemistry, Institute of Structural Chemistry, Chemical Research Center, Hungarian Academy of Sciences, Budapest (Hungary); Heja, Laszlo [Department of Neurochemistry, Institute of Biomolecular Chemistry, Chemical Research Center, Hungarian Academy of Sciences (Hungary); Kardos, Julianna, E-mail: jkardos@chemres.hu [Department of Neurochemistry, Institute of Biomolecular Chemistry, Chemical Research Center, Hungarian Academy of Sciences (Hungary)

    2009-07-24

    Crystal structures of transmembrane transport proteins belonging to the important families of neurotransmitter-sodium symporters reveal how they transport neurotransmitters across membranes. Substrate-induced structural conformations of gated neurotransmitter-sodium symporters have been in the focus of research, however, a key question concerning the mechanism of Na{sup +} ion coupling remained unanswered. Homology models of human glial transporter subtypes of the major inhibitory neurotransmitter {gamma}-aminobutyric acid were built. In accordance with selectivity data for subtype 2 vs. 3, docking and molecular dynamics calculations suggest similar orthosteric substrate (inhibitor) conformations and binding crevices but distinguishable allosteric Zn{sup 2+} ion binding motifs. Considering the occluded conformational states of glial human {gamma}-aminobutyric acid transporter subtypes, we found major semi-extended and minor ring-like conformations of zwitterionic {gamma}-aminobutyric acid in complex with Na{sup +} ion. The existence of the minor ring-like conformation of {gamma}-aminobutyric acid in complex with Na{sup +} ion may be attributed to the strengthening of the intramolecular H-bond by the electrostatic effect of Na{sup +} ion. Coupling substrate uptake into cells with the thermodynamically favorable Na{sup +} ion movement through substrate-Na{sup +} ion complex formation may be a mechanistic principle featuring transmembrane neurotransmitter-sodium symporter proteins.

  12. Pioneering instrumentation aspects of NA60

    International Nuclear Information System (INIS)

    David, Andre

    2004-01-01

    NA60 is taking data with proton and heavy-ion beams at the CERN SPS. Although building up on previous experiments, the dimuon physics programme of NA60 places very demanding requirements on its new detectors, in terms of radiation tolerance, granularity and read-out electronics speed. We start by comparing dimuon detection strategies in NA60 with those of previous experiments. We then describe the new detectors used in NA60, placing particular emphasis on their technological pioneering aspects as well as on their contributions to the overall physics performance of the experiment

  13. Fabrication of implanted $^{22}$Na targets

    CERN Multimedia

    2002-01-01

    A knowledge of the $^{22}$Na(p,$\\gamma$)$^{23}$ Mg reaction rate is of significant astrophysical interest. In order to complete previous studies of this reaction, radioactive $^{22}$Na targets of high purity are required. We ask for support to fabricate these targets via the implantation technique at ISOLDE GPS (off—line mode) using $^{22}$Na nuclides in an Al matrix produced in Nov. 1990 at the PSI (Zürich). The $^{22}$Na nuclides are released and ionized in a surface ionisation source, mass-analyzed at ISOLDE GPS, and implanted in a Ni-Ta backing and a C—foil in a special implantation setup.

  14. OGLAŠEVANJE NA FACEBOOKU V SLOVENIJI

    OpenAIRE

    Dobnik, Monja

    2013-01-01

    Danes so zahvaljujoč napredni mobilni tehnologiji družbena omrežja z nami na vsakem koraku. Facebook (FB) se po priljubljenosti uvršča v sam vrh družbenih omrežij in glede na to, da ga uporablja že več kot milijarda zemljanov, ponuja tudi odlične trg za oglaševanje. To so ugotovili tudi slovenski podjetniki. V diplomski nalogi je predstavljeno, kako na FB oglašujejo nekatera slovenska podjetja, s pomočjo spletnega vprašalnika pa je ugotovljeno tudi, kaj o oglasih na FB menijo njegovi uporabni...

  15. Entrada vocabular na linguagem virtual

    OpenAIRE

    Macedo, Valdete Aparecida Xavier de [UNESP

    2002-01-01

    O objetivo deste trabalho foi o de fazer um estudo sobre a projeção do inglês, língua universal, sobre a portuguesa, considerando-se os empréstimos lexicais, porta de entrada para a configuração e enriquecimento vocabular da língua de chegada. Estes vocábulos são indicativos ao vocabulário da língua de especialidade, divulgados nos programas da Internet. Fizemos uma pequena reflexão sobre o fenômeno da linguagem virtual, que vem se cristalizando em discurso interativo de povos e nações coloca...

  16. Zbigniew Herbert, Znaki na papierze

    Directory of Open Access Journals (Sweden)

    Thibault Deleixhe

    2008-10-01

    Full Text Available Dans une interview, Zbigniew Herbert confiait : « Mon travail préparatoire à un livre, ce sont avant tout des dessins. Je ne fais pas de photos, cela simplifierait mon contact avec l’objet. » Il n’en fallait pas moins pour donner aux éditions Bosz l’envie d’un projet : réunir ces précieuses esquisses de travail et les confronter aux textes qui en sont nés. Le résultat s’intitule Znaki na papierze (Signes sur papier et appartient aux objets que l’on est fier de posséder dans sa bibliothèque. ...

  17. O consumo na vida digital

    Directory of Open Access Journals (Sweden)

    Iuri Yudi Furukita Baptista

    2016-02-01

    Full Text Available O modelo de consumo não possui as mesmas características sempre: suas relações, motivações, formatos, espaços, interesses e atividades são construções sociais que se modificam atreladas ao cenário econômico, político e tecnológico. O presente trabalho repassa o surgimento da sociedade do consumidor para então conjecturar sobre as propriedades distintivas do consumo na vida digital. O que se defende ao final é que o consumidor já não se restringe ao papel de consumir.

  18. Suppression of NaNO3 crystal nucleation by glycerol: micro-Raman observation on the efflorescence process of mixed glycerol/NaNO3/water droplets.

    Science.gov (United States)

    Yu, Jun-Ying; Zhang, Yun; Zeng, Guang; Zheng, Chuan-Ming; Liu, Yong; Zhang, Yun-Hong

    2012-02-09

    Although the hygroscopicity of a NaNO(3)/water microdroplet and a polyalcohol/water microdroplet, two of the most important aerosols in atmosphere, has been widely studied, little is known about the relationship between the hygroscopic behavior of mixed NaNO(3)/polyalcohol/water droplets and their structures on the molecular level. In this study, the hygroscopicity of mixed glycerol/NaNO(3)/water droplets deposited on a hydrophobic substrate was studied by micro-Raman spectroscopy with organic-to-inorganic molar ratios (OIRs) of 0.5, 1, and 2. In the mixed glycerol/NaNO(3)/water droplets, glycerol molecules tended to combine with Na(+) and NO(3)(-) ions by electrostatic interaction and hydrogen bonding, respectively. On the basis of the analyses of the changes of symmetric stretching (v(s)-CH(2)), asymmetric stretching (v(a)-CH(2)), their area ratio (Av(a)-CH(2)/Av(s)-CH(2)) of glycerol, and symmetric stretching band of NO(3)(-) (ν(1)-NO(3)(-)) with relative humidity (RH), it was found that the conformation of glycerol was transformed from αα mainly to γγ and partly to αγ with a decreasing RH in the mixed droplets, contrary to the case in the glycerol/water droplet. In addition, the glycerol with γγ and αγ conformation had strong interaction with Na(+) and NO(3)(-) respectively, which suppressed the formation of contact of ions and delayed the efflorescence relative humidity (ERH) for the mixed droplets compared to the NaNO(3)/water droplet. © 2012 American Chemical Society

  19. The Na+/H+ exchanger controls deoxycholic acid-induced apoptosis by a H+-activated, Na+-dependent ionic shift in esophageal cells.

    Directory of Open Access Journals (Sweden)

    Aaron Goldman

    Full Text Available Apoptosis resistance is a hallmark of cancer cells. Typically, bile acids induce apoptosis. However during gastrointestinal (GI tumorigenesis the cancer cells develop resistance to bile acid-induced cell death. To understand how bile acids induce apoptosis resistance we first need to identify the molecular pathways that initiate apoptosis in response to bile acid exposure. In this study we examined the mechanism of deoxycholic acid (DCA-induced apoptosis, specifically the role of Na(+/H(+ exchanger (NHE and Na(+ influx in esophageal cells. In vitro studies revealed that the exposure of esophageal cells (JH-EsoAd1, CP-A to DCA (0.2 mM-0.5 mM caused lysosomal membrane perturbation and transient cytoplasmic acidification. Fluorescence microscopy in conjunction with atomic absorption spectrophotometry demonstrated that this effect on lysosomes correlated with influx of Na(+, subsequent loss of intracellular K(+, an increase of Ca(2+ and apoptosis. However, ethylisopropyl-amiloride (EIPA, a selective inhibitor of NHE, prevented Na(+, K(+ and Ca(2+ changes and caspase 3/7 activation induced by DCA. Ouabain and amphotericin B, two drugs that increase intracellular Na(+ levels, induced similar changes as DCA (ion imbalance, caspase3/7 activation. On the contrary, DCA-induced cell death was inhibited by medium with low a Na(+ concentrations. In the same experiments, we exposed rat ileum ex-vivo to DCA with or without EIPA. Severe tissue damage and caspase-3 activation was observed after DCA treatment, but EIPA almost fully prevented this response. In summary, NHE-mediated Na(+ influx is a critical step leading to DCA-induced apoptosis. Cells tolerate acidification but evade DCA-induced apoptosis if NHE is inhibited. Our data suggests that suppression of NHE by endogenous or exogenous inhibitors may lead to apoptosis resistance during GI tumorigenesis.

  20. Odpowiedź na pytanie

    Directory of Open Access Journals (Sweden)

    Michel Foucault

    2016-12-01

    Full Text Available Prezentowany artykuł Michela Foucaulta został opublikowany w 1963 roku. Foucault rozwija w nim koncepcję archeologii wiedzy – metody analizy historycznych dyskursów, którą zaprezentuje w sześć lat później w książce o tym właśnie tytule. Artykuł powstał na kanwie pytania wybranego przez autora spośród zadanych mu przez redakcję „Esprit”, które dotyczyło możliwości pojęciowego opracowania przymusu systemu dyskursywnego przy jednoczesnym zaakcentowaniu nieciągłości w jego obrębie a tym samym możliwości twórczego działania w historii ducha. A także, czy tak sformułowana aporia zakładałaby z konieczności zgodę na przymus systemu lub afirmację siły zdolnej do przekształcenia go za pomocą zewnętrznej przemocy? Tekst jest wprawką do sformułowania dojrzałej teorii dyskursu, rodzajem autoanalizy, która pozwala Foucaultowi powiązać własną metodę historyczną z „progresywistyczną polityką” myśli i rozwiązać w ten sposób dylemat pełnej determinacji i wolnego sprawstwa obecny w rozważaniach wielu strukturalistów.

  1. Gastronomia Molecular: Desconstruindo 20 anos de Uma Tendência

    Directory of Open Access Journals (Sweden)

    Joana Pellerano

    2013-06-01

    Full Text Available A gastronomia molecular gera interesse e controvérsia desde que foi criada, em 1992, nos workshops de Erice, na Itália. Da curiosidade dos cientistas Nicholas Kurti e Hervé This, que desenvolveram a disciplina, à aplicação prática encontrada por chefs de todo o mundo, a gastronomia molecular é perseguida por parecer ser mais complicada do que realmente é: o estudo meticuloso dos alimentos. O objetivo desse artigo é descrever o seu surgimento e o que trouxe ao cenário contemporâneo enquanto tendência gastronômica. Para tanto, foi realizada uma revisão bibliográfica em livros e citações na imprensa estrangeira, o que permitiu descrever os motivos para que essa forma de cozinhar cause tanta polêmica.

  2. Carbon dioxide sorption in a nanoporous octahedral molecular sieve

    Science.gov (United States)

    Williamson, Izaak; Nelson, Eric B.; Li, Lan

    2015-08-01

    We have performed first-principles density functional theory calculations, incorporated with van der Waals interactions, to study CO2 adsorption and diffusion in nanoporous solid—OMS-2 (Octahedral Molecular Sieve). We found the charge, type, and mobility of a cation, accommodated in a porous OMS-2 material for structural stability, can affect not only the OMS-2 structural features but also CO2 sorption performance. This paper targets K+, Na+, and Ba2+ cations. First-principles energetics and electronic structure calculations indicate that Ba2+ has the strongest interaction with the OMS-2 porous surface due to valence electrons donation to the OMS-2 and molecular orbital hybridization. However, the Ba-doped OMS-2 has the worst CO2 uptake capacity. We also found evidence of sorption hysteresis in the K- and Na-doped OMS-2 materials.

  3. Double rotation NMR studies of zeolites and aluminophosphate molecular sieves

    Energy Technology Data Exchange (ETDEWEB)

    Jelinek, Raz [Univ. of California, Berkeley, CA (United States)

    1993-07-01

    Goal is to study the organization and structures of guest atoms and molecules and their reactions on internal surfaces within pores of zeolites and aluminophosphate molecular sieves. 27Al and 23Na double rotation NMR (DOR) is used since it removes the anisotropic broadening in NMR spectra of quadrupolar nuclei, thus increasing resolution. This work concentrates on probing aluminum framework atoms in aluminophosphate molecular sieves and sodium extra framework cations in porous aluminosilicates. In aluminophosphates, ordering and electronic environments of the framework 27Al nuclei are modified upon adsorption of water molecules within the channels; a relation is sought between the sieve channel topology and the organization of adsorbed water, as well as the interaction between the Al nuclei and the water molecules. Extra framework Na+ cations are directly involved in adsorption processes and reactions in zeolite cavities.

  4. Tribological behavior of in situ Ag nanoparticles/polyelectrolyte composite molecular deposition films

    International Nuclear Information System (INIS)

    Guo Yanbao; Wang Deguo; Liu Shuhai

    2010-01-01

    Multilayer polyelectrolyte films containing silver ions were obtained by molecular deposition method on a glass plate or a quartz substrate. The in situ Ag nanoparticles were synthesized in the multilayer polyelectrolyte films which were put into fresh NaBH 4 aqueous solution. The structure and surface morphology of composite molecular deposition films were observed by UV-vis spectrophotometer, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Tribological characteristic was investigated by AFM and micro-tribometer. It was found that the in situ Ag nanoparticles/polyelectrolyte composite molecular deposition films have lower coefficient of friction and higher anti-wear life than pure polyelectrolyte molecular deposition films.

  5. Molecular dynamics simulations of a lithium/sodium carbonate mixture.

    Science.gov (United States)

    Ottochian, Alistar; Ricca, Chiara; Labat, Frederic; Adamo, Carlo

    2016-03-01

    The diffusion and ionic conductivity of Li x Na1-x CO3 salt mixtures were studied by means of Molecular Dynamics (MD) simulations, using the Janssen and Tissen model (Janssen and Tissen, Mol Simul 5:83-98; 1990). These salts have received particular attention due to their central role in fuel cells technology, and reliable numerical methods that could perform as important interpretative tool of experimental data are thus required but still lacking. The chosen computational model nicely reproduces the main structural behaviour of the pure Li2CO3, Na2CO3 and K2CO3 carbonates, but also of their Li/K and Li/Na mixtures. However, it fails to accurately describe dynamic properties such as activation energies of diffusion and conduction processes, outlining the need to develop more accurate models for the simulation of molten salt carbonates.

  6. Na+/Ca2+ exchange and Na+/K+-ATPase in the heart

    Science.gov (United States)

    Shattock, Michael J; Ottolia, Michela; Bers, Donald M; Blaustein, Mordecai P; Boguslavskyi, Andrii; Bossuyt, Julie; Bridge, John H B; Chen-Izu, Ye; Clancy, Colleen E; Edwards, Andrew; Goldhaber, Joshua; Kaplan, Jack; Lingrel, Jerry B; Pavlovic, Davor; Philipson, Kenneth; Sipido, Karin R; Xie, Zi-Jian

    2015-01-01

    This paper is the third in a series of reviews published in this issue resulting from the University of California Davis Cardiovascular Symposium 2014: Systems approach to understanding cardiac excitation–contraction coupling and arrhythmias: Na+ channel and Na+ transport. The goal of the symposium was to bring together experts in the field to discuss points of consensus and controversy on the topic of sodium in the heart. The present review focuses on cardiac Na+/Ca2+ exchange (NCX) and Na+/K+-ATPase (NKA). While the relevance of Ca2+ homeostasis in cardiac function has been extensively investigated, the role of Na+ regulation in shaping heart function is often overlooked. Small changes in the cytoplasmic Na+ content have multiple effects on the heart by influencing intracellular Ca2+ and pH levels thereby modulating heart contractility. Therefore it is essential for heart cells to maintain Na+ homeostasis. Among the proteins that accomplish this task are the Na+/Ca2+ exchanger (NCX) and the Na+/K+ pump (NKA). By transporting three Na+ ions into the cytoplasm in exchange for one Ca2+ moved out, NCX is one of the main Na+ influx mechanisms in cardiomyocytes. Acting in the opposite direction, NKA moves Na+ ions from the cytoplasm to the extracellular space against their gradient by utilizing the energy released from ATP hydrolysis. A fine balance between these two processes controls the net amount of intracellular Na+ and aberrations in either of these two systems can have a large impact on cardiac contractility. Due to the relevant role of these two proteins in Na+ homeostasis, the emphasis of this review is on recent developments regarding the cardiac Na+/Ca2+ exchanger (NCX1) and Na+/K+ pump and the controversies that still persist in the field. PMID:25772291

  7. Molecular Population Genetics.

    Science.gov (United States)

    Casillas, Sònia; Barbadilla, Antonio

    2017-03-01

    Molecular population genetics aims to explain genetic variation and molecular evolution from population genetics principles. The field was born 50 years ago with the first measures of genetic variation in allozyme loci, continued with the nucleotide sequencing era, and is currently in the era of population genomics. During this period, molecular population genetics has been revolutionized by progress in data acquisition and theoretical developments. The conceptual elegance of the neutral theory of molecular evolution or the footprint carved by natural selection on the patterns of genetic variation are two examples of the vast number of inspiring findings of population genetics research. Since the inception of the field, Drosophila has been the prominent model species: molecular variation in populations was first described in Drosophila and most of the population genetics hypotheses were tested in Drosophila species. In this review, we describe the main concepts, methods, and landmarks of molecular population genetics, using the Drosophila model as a reference. We describe the different genetic data sets made available by advances in molecular technologies, and the theoretical developments fostered by these data. Finally, we review the results and new insights provided by the population genomics approach, and conclude by enumerating challenges and new lines of inquiry posed by increasingly large population scale sequence data. Copyright © 2017 Casillas and Barbadilla.

  8. EDITORIAL: Molecular Imaging Technology

    Science.gov (United States)

    Asai, Keisuke; Okamoto, Koji

    2006-06-01

    'Molecular Imaging Technology' focuses on image-based techniques using nanoscale molecules as sensor probes to measure spatial variations of various species (molecular oxygen, singlet oxygen, carbon dioxide, nitric monoxide, etc) and physical properties (pressure, temperature, skin friction, velocity, mechanical stress, etc). This special feature, starting on page 1237, contains selected papers from The International Workshop on Molecular Imaging for Interdisciplinary Research, sponsored by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) in Japan, which was held at the Sendai Mediatheque, Sendai, Japan, on 8 9 November 2004. The workshop was held as a sequel to the MOSAIC International Workshop that was held in Tokyo in 2003, to summarize the outcome of the 'MOSAIC Project', a five-year interdisciplinary project supported by Techno-Infrastructure Program, the Special Coordination Fund for Promotion of Science Technology to develop molecular sensor technology for aero-thermodynamic research. The workshop focused on molecular imaging technology and its applications to interdisciplinary research areas. More than 110 people attended this workshop from various research fields such as aerospace engineering, automotive engineering, radiotechnology, fluid dynamics, bio-science/engineering and medical engineering. The purpose of this workshop is to stimulate intermixing of these interdisciplinary fields for further development of molecular sensor and imaging technology. It is our pleasure to publish the seven papers selected from our workshop as a special feature in Measurement and Science Technology. We will be happy if this issue inspires people to explore the future direction of molecular imaging technology for interdisciplinary research.

  9. Thermal Inactivation Kinetics and Secondary Structure Change of a Low Molecular Weight Halostable Exoglucanase from a Marine Aspergillus niger at High Salinities.

    Science.gov (United States)

    Xue, Dong-Sheng; Liang, Long-Yuan; Lin, Dong-Qiang; Yao, Shan-Jing

    2017-11-01

    Two kinds of exoglucanase were purified from a marine Aspergillus niger. Catalytic ability of halophilic exoglucanase with a lower molecular weight and secondary structure change was analyzed at different salinities. Activity of the low molecular weight exoglucanase in 10% NaCl solution (w/v) was 1.69-fold higher of that in NaCl-free solution. Half-life time in 10% NaCl solution (w/v) was over 1.27-fold longer of that in NaCl-free solution. Free energy change of the low molecular weight exoglucanase denaturation, △G, in 10% NaCl solution (w/v) was 0.54 kJ/mol more than that in NaCl-free solution. Melt point in 10% NaCl solution (w/v), 52.01 °C, was 4.21 °C higher than that in NaCl-free solution, 47.80 °C. K m value, 0.179 mg/ml in 10% NaCl solution (w/v) was less 0.044 mg/ml than that, 0.224 mg/ml, in NaCl-free solution. High salinity made content of α-helix increased. Secondary structure change caused by high salinities improved exoglucanase thermostability and catalysis activity. The halophilic exoglucanase from a marine A. niger was valuable for hydrolyzing cellulose at high salinities.

  10. Imaging of tumor viability in lung cancer. Initial results using 23Na-MRI

    International Nuclear Information System (INIS)

    Henzler, T.; Apfaltrer, P.; Haneder, S.; Schoenberg, S.O.; Fink, C.; Konstandin, S.; Schad, L.; Schmid-Bindert, G.; Manegold, C.; Wenz, F.

    2012-01-01

    23 Na-MRI has been proposed as a potential imaging biomarker for the assessment of tumor viability and the evaluation of therapy response but has not yet been evaluated in patients with lung cancer. We aimed to assess the feasibility of 23 Na-MRI in patients with lung cancer. Three patients with stage IV adenocarcinoma of the lung were examined on a clinical 3 Tesla MRI system (Magnetom TimTrio, Siemens Healthcare, Erlangen, Germany). Feasibility of 23 Na-MRI images was proven by comparison and fusion of 23 Na-MRI with 1 H-MR, CT and FDG-PET-CT images. 23 Na signal intensities (SI) of tumor and cerebrospinal fluid (CSF) of the spinal canal were measured and the SI ratio in tumor and CSF was calculated. One chemonaive patient was examined before and after the initiation of combination therapy (Carboplatin, Gemcitabin, Cetuximab). All 23 Na-MRI examinations were successfully completed and were of diagnostic quality. Fusion of 23 Na-MRI images with 1 H-MRI, CT and FDG-PET-CT was feasible in all patients and showed differences in solid and necrotic tumor areas. The mean tumor SI and the tumor/CSF SI ratio were 13.3 ± 1.8 x 103 and 0.83 ± 0.14, respectively. In necrotic tumors, as suggested by central non-FDG-avid areas, the mean tumor SI and the tumor/CSF ratio were 19.4 x 103 and 1.10, respectively. 23 Na-MRI is feasible in patients with lung cancer and could provide valuable functional molecular information regarding tumor viability, and potentially treatment response. (orig.)

  11. K+ Block Is the Mechanism of Functional Asymmetry in Bacterial Na(v Channels.

    Directory of Open Access Journals (Sweden)

    Van Ngo

    2016-01-01

    Full Text Available Crystal structures of several bacterial Na(v channels have been recently published and molecular dynamics simulations of ion permeation through these channels are consistent with many electrophysiological properties of eukaryotic channels. Bacterial Na(v channels have been characterized as functionally asymmetric, and the mechanism of this asymmetry has not been clearly understood. To address this question, we combined non-equilibrium simulation data with two-dimensional equilibrium unperturbed landscapes generated by umbrella sampling and Weighted Histogram Analysis Methods for multiple ions traversing the selectivity filter of bacterial Na(vAb channel. This approach provided new insight into the mechanism of selective ion permeation in bacterial Na(v channels. The non-equilibrium simulations indicate that two or three extracellular K+ ions can block the entrance to the selectivity filter of Na(vAb in the presence of applied forces in the inward direction, but not in the outward direction. The block state occurs in an unstable local minimum of the equilibrium unperturbed free-energy landscape of two K+ ions that can be 'locked' in place by modest applied forces. In contrast to K+, three Na+ ions move favorably through the selectivity filter together as a unit in a loose "knock-on" mechanism of permeation in both inward and outward directions, and there is no similar local minimum in the two-dimensional free-energy landscape of two Na+ ions for a block state. The useful work predicted by the non-equilibrium simulations that is required to break the K+ block is equivalent to large applied potentials experimentally measured for two bacterial Na(v channels to induce inward currents of K+ ions. These results illustrate how inclusion of non-equilibrium factors in the simulations can provide detailed information about mechanisms of ion selectivity that is missing from mechanisms derived from either crystal structures or equilibrium unperturbed free

  12. Molecularly Imprinted Membranes

    Science.gov (United States)

    Trotta, Francesco; Biasizzo, Miriam; Caldera, Fabrizio

    2012-01-01

    Although the roots of molecularly imprinted polymers lie in the beginning of 1930s in the past century, they have had an exponential growth only 40–50 years later by the works of Wulff and especially by Mosbach. More recently, it was also proved that molecular imprinted membranes (i.e., polymer thin films) that show recognition properties at molecular level of the template molecule are used in their formation. Different procedures and potential application in separation processes and catalysis are reported. The influences of different parameters on the discrimination abilities are also discussed. PMID:24958291

  13. Photoionization and molecular structure

    International Nuclear Information System (INIS)

    Palma, A.

    1983-01-01

    A presentation is here given of the theoretical work on photoionization and molecular structure carried out by the author and coworkers. The implications of the photoionization process on the molecular geometry are emphasized. In particular, the ionization effect on deep orbitals is considered and it is shown that, contrary to traditional thinking, these orbitals have relevant effects on the molecular geometry. The problem of calculating photoionization relative intensities for the full spectrum is also considered, and the results of the present model are compared with experimental and other theoretical results. (author)

  14. Systematic Study of Binding of μ-Conotoxins to the Sodium Channel NaV1.4

    Directory of Open Access Journals (Sweden)

    Somayeh Mahdavi

    2014-12-01

    Full Text Available Voltage-gated sodium channels (NaV are fundamental components of the nervous system. Their dysfunction is implicated in a number of neurological disorders, such as chronic pain, making them potential targets for the treatment of such disorders. The prominence of the NaV channels in the nervous system has been exploited by venomous animals for preying purposes, which have developed toxins that can block the NaV channels, thereby disabling their function. Because of their potency, such toxins could provide drug leads for the treatment of neurological disorders associated with NaV channels. However, most toxins lack selectivity for a given target NaV channel, and improving their selectivity profile among the NaV1 isoforms is essential for their development as drug leads. Computational methods will be very useful in the solution of such design problems, provided accurate models of the protein-ligand complex can be constructed. Using docking and molecular dynamics simulations, we have recently constructed a model for the NaV1.4-μ-conotoxin-GIIIA complex and validated it with the ample mutational data available for this complex. Here, we use the validated NaV1.4 model in a systematic study of binding other μ-conotoxins (PIIIA, KIIIA and BuIIIB to NaV1.4. The binding mode obtained for each complex is shown to be consistent with the available mutation data and binding constants. We compare the binding modes of PIIIA, KIIIA and BuIIIB to that of GIIIA and point out the similarities and differences among them. The detailed information about NaV1.4-μ-conotoxin interactions provided here will be useful in the design of new NaV channel blocking peptides.

  15. Na-no-body : De l’oubli du corps sensible en nanomédecine

    Directory of Open Access Journals (Sweden)

    Noury, Mathieu

    2016-09-01

    Full Text Available This article presents the ethical reflexion of a recent art project, Na-no-body, presented at the Montreal gallery Espace Projet in the context of the exposition Art + Bioéthique. Na-no-body is the result of a collaborative work between the artist Stephanie Coleman and the sociologist Mathieu Noury. The aim of this project was to open an ethical dialogue on nanomedicine and its relationship with the body. To do so, the article examines specifically the notion of “personalized medicine” promoted by nanomedicine. This article proposes that, far from developing an approach reintegrating the person and the personal experience of illness at the heart of the care relationship, nanomedicine brings a simple molecular and technical response to caring. It is argued that two major themes constitute the core of this notion: 1 a molecular conception of personalization, and 2 a technical conception of personalization.

  16. Ab initio interionic potentials for NaCl by multiple lattice inversion

    International Nuclear Information System (INIS)

    Zhang Shuo; Chen Nanxian

    2002-01-01

    Based on the Chen-Moebius lattice inversion and a series of pseudopotential total-energy curves, a different method is presented to derive the ab initio interionic pair potentials for B1-type ionic crystals. Comparing with the experimental data, the static properties of B1- and B2-type NaCl are well reproduced by the interionic potentials. Moreover, the phase stability of B1-NaCl has been described by the energy minimizations from the global deformed and disturbed states. The molecular-dynamics simulations for the molten NaCl indicate that the calculated mean-square displacements, radial distribution function, and diffusion coefficients gain good agreements with the experimental results. It can be concluded that the inversion pair potentials are valid over a wide range of interionic separations for describing the structural properties of B1-type ionic crystals

  17. Cross sections and coherence terms for associative ionization of two differently excited Na(3p) atoms

    International Nuclear Information System (INIS)

    Meijer, H.A.J.; Pelgrim, T.J.C.; Heideman, H.G.M.; Morgenstern, R.; Andersen, N.

    1988-01-01

    The associative ionization process in thermal Na(3p)-Na(3p) encounters has been studied in a series of crossed-beam experiments where the light polarization of the two laser beams preparing the excited atoms before collision was varied independently. It is shown how in this way maximum possible information for our geometry is extracted about the dependence of the ion formation process on the shape and spatial orientation of the electron clouds of the two approaching atoms, including all coherence terms. The experimental findings are discussed in the light of recent theoretical results for the states of the Na 2 molecule. It is concluded that just a few of the possible geometrical approaches are favourable for molecular-ion formation. (orig.)

  18. Kinetin Reversal of NaCl Effects

    Science.gov (United States)

    Katz, Adriana; Dehan, Klara; Itai, Chanan

    1978-01-01

    Leaf discs of Nicotiana rustica L. were floated on NaCl in the presence of kinetin or abscisic acid. On the 5th day 14CO2 fixation, [3H]leucine incorporation, stomatal conductance, and chlorophyll content were determined. Kinetin either partially or completely reversed the inhibitory effects of NaCl while ABA had no effect. PMID:16660618

  19. Silicene for Na-ion battery applications

    KAUST Repository

    Zhu, Jiajie; Schwingenschlö gl, Udo

    2016-01-01

    Na-ion batteries are promising candidates to replace Li-ion batteries in large scale applications because of the advantages in natural abundance and cost of Na. Silicene has potential as the anode in Li-ion batteries but so far has not received

  20. Negative electrodes for Na-ion batteries.

    Science.gov (United States)

    Dahbi, Mouad; Yabuuchi, Naoaki; Kubota, Kei; Tokiwa, Kazuyasu; Komaba, Shinichi

    2014-08-07

    Research interest in Na-ion batteries has increased rapidly because of the environmental friendliness of sodium compared to lithium. Throughout this Perspective paper, we report and review recent scientific advances in the field of negative electrode materials used for Na-ion batteries. This paper sheds light on negative electrode materials for Na-ion batteries: carbonaceous materials, oxides/phosphates (as sodium insertion materials), sodium alloy/compounds and so on. These electrode materials have different reaction mechanisms for electrochemical sodiation/desodiation processes. Moreover, not only sodiation-active materials but also binders, current collectors, electrolytes and electrode/electrolyte interphase and its stabilization are essential for long cycle life Na-ion batteries. This paper also addresses the prospect of Na-ion batteries as low-cost and long-life batteries with relatively high-energy density as their potential competitive edge over the commercialized Li-ion batteries.

  1. Razvitak naselja na kvarnerskim otocima - primjer Dobrinja

    Directory of Open Access Journals (Sweden)

    Marijan Bradanović

    2012-12-01

    Full Text Available Na dosad slabo poznatom i sa stajališta povijesti umjetnosti još posve neobrađenom primjeru Dobrinja na otoku Krku, raspravlja se o razvitku naselja na kvarnerskim otocima. Uz isticanje štetnosti dosad prevladavajućih uopćavanja, karakteristični položaj i razvitak Dobrinja tumače se u širem, komparativnom kontekstu. Analiziraju se prostiranje i obilježja pojedinih dijelova ovog naselja, a naglasak je na vremenu kasnog srednjeg i ranijeg novog vijeka. Tada je najuži dio povijesnog središta Dobrinja poprimio čvrstu, na tlorisnoj osnovi i danas, usprkos opsežnim pregradnjama i arhitektonskim preinakama, jasno uočljivu, urbanu fizionomiju.

  2. 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...

  3. Molecular electronic junction transport

    DEFF Research Database (Denmark)

    Solomon, Gemma C.; Herrmann, Carmen; Ratner, Mark

    2012-01-01

    Whenasinglemolecule,oracollectionofmolecules,isplacedbetween two electrodes and voltage is applied, one has a molecular transport junction. We discuss such junctions, their properties, their description, and some of their applications. The discussion is qualitative rather than quantitative, and f...

  4. Atomic and Molecular Interactions

    International Nuclear Information System (INIS)

    2002-01-01

    The Gordon Research Conference (GRC) on Atomic and Molecular Interactions was held at Roger Williams University, Bristol, RI. Emphasis was placed on current unpublished research and discussion of the future target areas in this field

  5. Noncovalent Molecular Electronics.

    Science.gov (United States)

    Gryn'ova, G; Corminboeuf, C

    2018-05-03

    Molecular electronics covers several distinctly different conducting architectures, including organic semiconductors and single-molecule junctions. The noncovalent interactions, abundant in the former, are also often found in the latter, i.e., the dimer junctions. In the present work, we draw the parallel between the two types of noncovalent molecular electronics for a range of π-conjugated heteroaromatic molecules. In silico modeling allows us to distill the factors that arise from the chemical nature of their building blocks and from their mutual arrangement. We find that the same compounds are consistently the worst and the best performers in the two types of electronic assemblies, emphasizing the universal imprint of the underlying chemistry of the molecular cores on their diverse charge transport characteristics. The interplay between molecular and intermolecular factors creates a spectrum of noncovalent conductive architectures, which can be manipulated using the design strategies based upon the established relationships between chemistry and transport.

  6. The Molecular Foundry (TMF)

    Data.gov (United States)

    Federal Laboratory Consortium — Founded in 2006 by the Department of Energy (DOE), the Molecular Foundry is a critical part of the DOE's National Nanotechnology Initiative, a multi-agency framework...

  7. Molecular ion photofragment spectroscopy

    International Nuclear Information System (INIS)

    Bustamente, S.W.

    1983-11-01

    A new molecular ion photofragment spectrometer is described which features a supersonic molecular beam ion source and a radio frequency octapole ion trap interaction region. This unique combination allows several techniques to be applied to the problem of detecting a photon absorption event of a molecular ion. In particular, it may be possible to obtain low resolution survey spectra of exotic molecular ions by using a direct vibrational predissociation process, or by using other more indirect detection methods. The use of the spectrometer is demonstrated by measuring the lifetime of the O 2 + ( 4 π/sub u/) metastable state which is found to consist of two main components: the 4 π/sub 5/2/ and 4 π/sub -1/2/ spin components having a long lifetime (approx. 129 ms) and the 4 π/sub 3/2/ and 4 π/sub 1/2/ spin components having a short lifetime (approx. 6 ms)

  8. Crossed molecular beams

    International Nuclear Information System (INIS)

    Lee, Y.T.

    1976-01-01

    Research activities with crossed molecular beams at Lawrence Berkeley Laboratory during 1976 are described. Topics covered include: scattering of Ar*, Kr*, with Xe; metastable rare gas interactions, He* + H 2 ; an atomic and molecular halogen beam source; a crossed molecular beam study of the Cl + Br 2 → BrCl + Br reaction; O( 3 P) reaction dynamics, development of the high pressure plasma beam source; energy randomization in the Cl + C 2 H 3 Br → Br + C 2 H 3 Cl reaction; high resolution photoionization studies of NO and ICl; photoionization of (H 2 O)/sub n/ and (NH 3 ) 2 ; photoionization mass spectroscopy of NH 3 + and O 3 + ; photo fragmentation of bromine; and construction of chemiluminescence-laser fluorescence crossed molecular beam machine

  9. Preparation and Characterization of High Silica Molecular Sieve from Rice Husk

    International Nuclear Information System (INIS)

    Hnaung Hnaung Win; Tin Tin Aye; Kyaw Myo Naing; Nyunt Wynn

    2008-03-01

    A mordenite type of hight silica molecular sieve with a formula composition Na32 (ALO2)32 (SiO2)176 192H2O having a high molar ratio of SiO2 /Al2O3 (5.4) with a percent yield of 98.76% has been prepared from synthesized zeolite NaY and glycolato silicate on the basis of hydrothermal condition.Zeolicate NaY and glycolato silicate were synthesized by using 98.34% purified silica which was extracted from rice husk.The characterizations with XRD, FT-IR, EDXRF,TG-DTA and SEM techniques were studied.

  10. A complete analysis of HA and NA genes of influenza A viruses.

    LENUS (Irish Health Repository)

    Shi, Weifeng

    2010-12-01

    More and more nucleotide sequences of type A influenza virus are available in public databases. Although these sequences have been the focus of many molecular epidemiological and phylogenetic analyses, most studies only deal with a few representative sequences. In this paper, we present a complete analysis of all Haemagglutinin (HA) and Neuraminidase (NA) gene sequences available to allow large scale analyses of the evolution and epidemiology of type A influenza.

  11. Bullying na Escola: um sofrimento

    Directory of Open Access Journals (Sweden)

    Marlene Silva Sardinha Gurpilhares

    2014-07-01

    Full Text Available O bullying é uma forma de violência presente nas escolas e o termo é utilizado para caracterizar todas as formas de agressões repetitivas psicológicas e físicas, direta ou indiretamente. Esta violência causa sofrimentos, intimidação e medo, sempre numa relação de poder entre pares. Esta pesquisa trata de um estudo do bullying escolar: o que é, como surgiu, como identificá-lo e sua caracterização, conseqüências, causas, o papel da escola, de professores e pais e uma proposta prática que pode ser adotada para sua prevenção e contenção. O objetivo é organizar materiais para leitura dos atores educacionais para uma possível reflexão, através de pesquisas bibliográficas. Esta violência é grave e deveria ser tratada como saúde pública, devido às conseqüências que traz, como queda na aprendizagem, na autoestima e em casos mais graves, até o suicido e outras tragédias. A escola necessita atentar para esse tipo de violência, revendo suas ações em todos os momentos, tendo um olhar integral e diferenciado em relação aos alunos. É fundamental que o bullying não seja tratado como brincadeira de criança e para ser identificado e combatido é necessária uma ação entre a família e todos da escola, que pode ser desenvolvida através de projetos que ajudem a apontar caminhos para a solução do problema. Tais ações devem ser pautadas por constantes debates e reflexões, nas quais o aluno se torne o protagonista. Não existem fórmulas prontas, pois a intervenção deve ser feita através da realidade de cada escola.

  12. Study of the Na-C-O and Na-H-O ternary systems in the sodium rich corner

    International Nuclear Information System (INIS)

    Maupre, J.-P.

    1978-02-01

    The purpose of this study is to provide a contribution to the understanding of the sodium - carbon - oxygen and sodium - hydrogen - oxygen ternary systems in the sodium rich corner. In order to do this the Na-NaH-Na 2 O-NaOH phase diagram was completed and the Na-Na 2 O-Na 2 CO 3 -C phase diagram was outlined. This work is made up of two parts. The first is devoted to a critical literature survey essential to establish correct phase diagrams. The second is an experimental study followed by a discussion collating our finding to the literary data. The basic experimental technique used is differential thermal analysis (DTA) but it has been completed by quenching, X-ray and chemical analysis methods. The proposed phase diagrams imply that Na-NaH-Na 2 O-NaOH and Na-Na 2 O-Na 2 CO 3 -C systems are reciprocal ternary systems. Temperatures of stable pairs reversal are respectively 410 and 690 0 C. The stable pairs are Na-NaOH and Na-Na 2 CO 3 at elevated temperature, Na 2 O-NaH and Na 2 O-C at low temperature [fr

  13. Molecular Electronic Shift Registers

    Science.gov (United States)

    Beratan, David N.; Onuchic, Jose N.

    1990-01-01

    Molecular-scale shift registers eventually constructed as parts of high-density integrated memory circuits. In principle, variety of organic molecules makes possible large number of different configurations and modes of operation for such shift-register devices. Several classes of devices and implementations in some specific types of molecules proposed. All based on transfer of electrons or holes along chains of repeating molecular units.

  14. Molecular imaging in oncology

    Energy Technology Data Exchange (ETDEWEB)

    Schober, Otmar; Riemann, Burkhard (eds.) [Universitaetsklinikum Muenster (Germany). Klinik fuer Nuklearmedizin

    2013-02-01

    Considers in detail all aspects of molecular imaging in oncology, ranging from basic research to clinical applications in the era of evidence-based medicine. Examines technological issues and probe design. Discusses preclinical studies in detail, with particular attention to multimodality imaging. Presents current clinical use of PET/CT, SPECT/CT, and optical imagingWritten by acknowledged experts. The impact of molecular imaging on diagnostics, therapy, and follow-up in oncology is increasing significantly. The process of molecular imaging includes key biotarget identification, design of specific molecular imaging probes, and their preclinical evaluation, e.g., in vivo using small animal studies. A multitude of such innovative molecular imaging probes have already entered clinical diagnostics in oncology. There is no doubt that in future the emphasis will be on multimodality imaging in which morphological, functional, and molecular imaging techniques are combined in a single clinical investigation that will optimize diagnostic processes. This handbook addresses all aspects of molecular imaging in oncology, ranging from basic research to clinical applications in the era of evidence-based medicine. The first section is devoted to technology and probe design, and examines a variety of PET and SPECT tracers as well as multimodality probes. Preclinical studies are then discussed in detail, with particular attention to multimodality imaging. In the third section, diverse clinical applications are presented, and the book closes by looking at future challenges. This handbook will be of value to all who are interested in the revolution in diagnostic oncology that is being brought about by molecular imaging.

  15. Human papillomavirus molecular biology.

    Science.gov (United States)

    Harden, Mallory E; Munger, Karl

    Human papillomaviruses are small DNA viruses with a tropism for squamous epithelia. A unique aspect of human papillomavirus molecular biology involves dependence on the differentiation status of the host epithelial cell to complete the viral lifecycle. A small group of these viruses are the etiologic agents of several types of human cancers, including oral and anogenital tract carcinomas. This review focuses on the basic molecular biology of human papillomaviruses. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Molecular imaging in oncology

    International Nuclear Information System (INIS)

    Schober, Otmar; Riemann, Burkhard

    2013-01-01

    Considers in detail all aspects of molecular imaging in oncology, ranging from basic research to clinical applications in the era of evidence-based medicine. Examines technological issues and probe design. Discusses preclinical studies in detail, with particular attention to multimodality imaging. Presents current clinical use of PET/CT, SPECT/CT, and optical imagingWritten by acknowledged experts. The impact of molecular imaging on diagnostics, therapy, and follow-up in oncology is increasing significantly. The process of molecular imaging includes key biotarget identification, design of specific molecular imaging probes, and their preclinical evaluation, e.g., in vivo using small animal studies. A multitude of such innovative molecular imaging probes have already entered clinical diagnostics in oncology. There is no doubt that in future the emphasis will be on multimodality imaging in which morphological, functional, and molecular imaging techniques are combined in a single clinical investigation that will optimize diagnostic processes. This handbook addresses all aspects of molecular imaging in oncology, ranging from basic research to clinical applications in the era of evidence-based medicine. The first section is devoted to technology and probe design, and examines a variety of PET and SPECT tracers as well as multimodality probes. Preclinical studies are then discussed in detail, with particular attention to multimodality imaging. In the third section, diverse clinical applications are presented, and the book closes by looking at future challenges. This handbook will be of value to all who are interested in the revolution in diagnostic oncology that is being brought about by molecular imaging.

  17. OGLAŠEVANJE NA DRUŽBENIH OMREŽJIH NA PRIMERU FACEBOOKA

    OpenAIRE

    Novak, Martina

    2012-01-01

    V diplomskem delu obravnavamo družbene medije kot novo priložnost za promocijo in oglaševanje podjetij. Spoznali smo družbena omrežja na splošno in nekaj teh, ki jih uporabljamo tudi v Sloveniji na kratko predstavili. Podrobneje smo se osredotočili na družbeno omrežje Facebook, predvsem na samo spletno stran, njen izgled in storitve, ki jih ponuja uporabnikom. V nalogi je podrobneje opisan Facebook kot orodje za uporabo oglaševanja. Spoznali smo brezplačne in plačljive načine promocije in ogl...

  18. Induced pluripotent stem cells derived from rabbits exhibit some characteristics of naïve pluripotency

    Directory of Open Access Journals (Sweden)

    Pierre Osteil

    2013-05-01

    Not much is known about the molecular and functional features of pluripotent stem cells (PSCs in rabbits. To address this, we derived and characterized 2 types of rabbit PSCs from the same breed of New Zealand White rabbits: 4 lines of embryonic stem cells (rbESCs, and 3 lines of induced PSCs (rbiPSCs that were obtained by reprogramming adult skin fibroblasts. All cell lines required fibroblast growth factor 2 for their growth and proliferation. All rbESC lines showed molecular and functional properties typically associated with primed pluripotency. The cell cycle of rbESCs had a prolonged G1 phase and a DNA damage checkpoint before entry into the S phase, which are the 2 features typically associated with the somatic cell cycle. In contrast, the rbiPSC lines exhibited some characteristics of naïve pluripotency, including resistance to single-cell dissociation by trypsin, robust activity of the distal enhancer of the mouse Oct4 gene, and expression of naïve pluripotency-specific genes, as defined in rodents. According to gene expression profiles, rbiPSCs were closer to the rabbit inner cell mass (ICM than rbESCs. Furthermore, rbiPSCs were capable of colonizing the ICM after aggregation with morulas. Therefore, we propose that rbiPSCs self-renew in an intermediate state between naïve and primed pluripotency, which represents a key step toward the generation of bona fide naïve PSC lines in rabbits.

  19. 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...

  20. Cardiovascular Molecular Imaging

    International Nuclear Information System (INIS)

    Lee, Kyung Han

    2009-01-01

    Molecular imaging strives to visualize processes in living subjects at the molecular level. Monitoring biochemical processes at this level will allow us to directly track biological processes and signaling events that lead to pathophysiological abnormalities, and help make personalized medicine a reality by allowing evaluation of therapeutic efficacies on an individual basis. Although most molecular imaging techniques emerged from the field of oncology, they have now gradually gained acceptance by the cardiovascular community. Hence, the availability of dedicated high-resolution small animal imaging systems and specific targeting imaging probes is now enhancing our understanding of cardiovascular diseases and expediting the development of newer therapies. Examples include imaging approaches to evaluate and track the progress of recent genetic and cellular therapies for treatment of myocardial ischemia. Other areas include in vivo monitoring of such key molecular processes as angiogenesis and apoptosis. Cardiovascular molecular imaging is already an important research tool in preclinical experiments. The challenge that lies ahead is to implement these techniques into the clinics so that they may help fulfill the promise of molecular therapies and personalized medicine, as well as to resolve disappointments and controversies surrounding the field

  1. Molecular toxicity of nanomaterials.

    Science.gov (United States)

    Chang, Xue-Ling; Yang, Sheng-Tao; Xing, Gengmei

    2014-10-01

    With the rapid developments in the fields of nanoscience and nanotechnlogy, more and more nanomaterials and their based consumer products have been used into our daily life. The safety concerns of nanomaterials have been well recognized by the scientific community and the public. Molecular mechanism of interactions between nanomaterials and biosystems is the most essential topic and final core of the biosafety. In the last two decades, nanotoxicology developed very fast and toxicity phenomena of nanomaterials have been reported. To achieve better understanding and detoxication of nanomaterials, thorough studies of nanotoxicity at molecular level are important. The interactions between nanomaterials and biomolecules have been widely investigated as the first step toward the molecular nanotoxicology. The consequences of such interactions have been discussed in the literature. Besides this, the chemical mechanism of nanotoxicology is gaining more attention, which would lead to a better design of nontoxic nanomaterials. In this review, we focus on the molecular nanotoxicology and explore the toxicity of nanomaterials at molecular level. The molecular level studies of nanotoxicology are summarized and the published nanotoxicological data are revisited.

  2. Coherent Control of Ground State NaK Molecules

    Science.gov (United States)

    Yan, Zoe; Park, Jee Woo; Loh, Huanqian; Will, Sebastian; Zwierlein, Martin

    2016-05-01

    Ultracold dipolar molecules exhibit anisotropic, tunable, long-range interactions, making them attractive for the study of novel states of matter and quantum information processing. We demonstrate the creation and control of 23 Na40 K molecules in their rovibronic and hyperfine ground state. By applying microwaves, we drive coherent Rabi oscillations of spin-polarized molecules between the rotational ground state (J=0) and J=1. The control afforded by microwave manipulation allows us to pursue engineered dipolar interactions via microwave dressing. By driving a two-photon transition, we are also able to observe Ramsey fringes between different J=0 hyperfine states, with coherence times as long as 0.5s. The realization of long coherence times between different molecular states is crucial for applications in quantum information processing. NSF, AFOSR- MURI, Alfred P. Sloan Foundation, DARPA-OLE

  3. Formation of ultracold NaRb Feshbach molecules

    International Nuclear Information System (INIS)

    Wang, Fudong; He, Xiaodong; Li, Xiaoke; Zhu, Bing; Chen, Jun; Wang, Dajun

    2015-01-01

    We report the creation of ultracold bosonic 23 Na 87 Rb Feshbach molecules via magneto-association. By ramping the magnetic field across an interspecies Feshbach resonance (FR), at least 4000 molecules can be produced out of the near degenerate ultracold mixture. Fast loss due to inelastic atom–molecule collisions is observed, which limits the pure molecule number, after residual atoms removal, to 1700. The pure molecule sample can live for 21.8(8) ms in the optical trap, long enough for future molecular spectroscopy studies toward coherently transferring to the singlet ro-vibrational ground state, where these molecules are stable against chemical reaction and have a permanent electric dipole moment of 3.3 Debye. We have also measured the Feshbach molecule’s binding energy near the FR by the oscillating magnetic field method and found these molecules have a large closed-channel fraction. (paper)

  4. Computer simulation of aqueous Na-Cl electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Hummer, G. [Los Alamos National Lab., NM (United States); Soumpasis, D.M. [Max-Planck-Institut fuer Biophysikalische Chemie (Karl-Friedrich-Bonhoeffer-Institut), Goettingen (Germany); Neumann, M. [Vienna Univ. (Austria). Inst. fuer Experimentalphysik

    1993-11-01

    Equilibrium structure of aqueous Na-Cl electrolytes between 1 and 5 mol/l is studied by means of molecular dynamics computer simulation using interaction site descriptions of water and ionic components. Electrostatic interactions are treated both with the newly developed charged-clouds scheme and with Ewald summation. In the case of a 5 mol/l electrolyte, the results for pair correlations obtained by the two methods are in excellent agreement. However, the charged-clouds technique is much faster than Ewald summation and makes simulations at lower salt concentrations feasible. It is found that both ion-water and ion-ion correlation functions depend only weakly on the ionic concentration. Sodium and chloride ions exhibit only a negligible tendency to form contact pairs. In particular, no chloride ion pairs in contact are observed.

  5. Computer simulation of aqueous Na-Cl electrolytes

    International Nuclear Information System (INIS)

    Hummer, G.; Soumpasis, D.M.; Neumann, M.

    1993-01-01

    Equilibrium structure of aqueous Na-Cl electrolytes between 1 and 5 mol/l is studied by means of molecular dynamics computer simulation using interaction site descriptions of water and ionic components. Electrostatic interactions are treated both with the newly developed charged-clouds scheme and with Ewald summation. In the case of a 5 mol/l electrolyte, the results for pair correlations obtained by the two methods are in excellent agreement. However, the charged-clouds technique is much faster than Ewald summation and makes simulations at lower salt concentrations feasible. It is found that both ion-water and ion-ion correlation functions depend only weakly on the ionic concentration. Sodium and chloride ions exhibit only a negligible tendency to form contact pairs. In particular, no chloride ion pairs in contact are observed

  6. Terapia de linguagem na afasia

    Directory of Open Access Journals (Sweden)

    Mauro Spinelli

    1977-12-01

    Full Text Available A terapia da linguagem na afasia foi estudada em 15 pacientes, 8 do sexo masculino e 7 do sexo feminino; a idade variou de menos de 10 anos a mais de 50 anos; em 11 casos a afasia era sequela de acidente vascular cerebral e, em 4, de traumatismo crânio-encefálico. Quanto ao tipo de afasia, 5 pacientes apresentavam déficits predominantemente de expressão e 10 apresentavam déficits receptivos e expressivos em graus equiparáveis. Em 6 casos a terapia foi iniciada dentro dos 3 primeiros meses de instalação do quadro; nos restantes foi iniciada mais tardiamente. Dos 15 pacientes, 11 apresentaram evolução satisfatória, a qual não depndeu do grau de afasia, do tipo de afasia, da idade do paciente, do tipo de patologia e do intervalo entre a instalação do quadro afásico e o início da terapia. A terapia da linguagem no paciente afásico é efetiva, o prognóstico não pode ser feito a priori. Somente a evolução do caso com sua retestagem criteriosa poderá dar dados realmente úteis para se falar em evolução.

  7. Extracellular Na+ levels regulate formation and activity of the NaX/alpha1-Na+/K+-ATPase complex in neuronal cells.

    Directory of Open Access Journals (Sweden)

    Emmanuelle eBerret

    2014-12-01

    Full Text Available MnPO neurons play a critical role in hydromineral homeostasis regulation by acting as sensors of extracellular sodium concentration ([Na+]out. The mechanism underlying Na+-sensing involves Na+-flow through the NaX channel, directly regulated by the Na+/K+-ATPase α1-isoform which controls Na+-influx by modulating channel permeability. Together, these two partners form a complex involved in the regulation of intracellular sodium ([Na+]in. Here we aim to determine whether environmental changes in Na+ could actively modulate the NaX/Na+/K+-ATPase complex activity.We investigated the complex activity using patch-clamp recordings from rat MnPO neurons and Neuro2a cells. When the rats were fed with a high-salt-diet, or the [Na+] in the culture medium was increased, the activity of the complex was up-regulated. In contrast, drop in environmental [Na+] decreased the activity of the complex. Interestingly under hypernatremic condition, the colocalization rate and protein level of both partners were up-regulated. Under hyponatremic condition, only NaX protein expression was increased and the level of NaX/Na+/K+-ATPase remained unaltered. This unbalance between NaX and Na+/K+-ATPase pump proportion would induce a bigger portion of Na+/K+-ATPase-control-free NaX channel. Thus we suggest that hypernatremic environment increases NaX/Na+/K+-ATPase α1-isoform activity by increasing the number of both partners and their colocalization rate, whereas hyponatremic environment down-regulates complex activity via a decrease in the relative number of NaX channels controlled by the pump.

  8. Artesanato na terceira idade: um estudo na cidade de Sinop

    Directory of Open Access Journals (Sweden)

    Rosane Marlene Weber

    2012-06-01

    Full Text Available O presente artigo sobre o artesanato e a Terceira Idade, pesquisa realizada em 2011, teve como metodologia o Estudo de Caso do tipo etnográfico. A metodologia de investigação ocorreu por meio de entrevistas semiestruturadas, orais e transcritas, observação e fotografias dos artesanatos em locais de venda e nas residências dos artesãos. Os sujeitos da pesquisa foram: a presidente da Associação da Casa do Artesão de Sinop-MT e oito artesãos. O objetivo foi mostrar a importância do artesanato como atividade educacional e como produtora de autonomia e autoria para os artesãos da Terceira Idade, motivados em realizar este trabalho nesta fase da vida. Para o embasamento teórico utilizou-se obras de Paulo Freire, Moacir Gadotti e sobre a Terceira Idade a coleção de Vivaidade com a organizadora Anita Liberalesso Neri. A análise das entrevistas mostrou que o artesanato traz autonomia educacional quando o idoso busca sozinho aprender sobre o objeto a ser realizado, assim como autonomia financeira, uma vez que a venda do artesanato proporciona certa independência econômica. Em relação ao sentimento de autoria das peças criadas constatou-se muita satisfação e realização, o que motiva a continuar sendo úteis e produtivos na Terceira Idade com muita criatividade. Palavras-chave: educação; terceira idade; artesanato; autonomia; autoria.

  9. Crystal structure of Na+, K(+)-ATPase in the Na(+)-bound state.

    Science.gov (United States)

    Nyblom, Maria; Poulsen, Hanne; Gourdon, Pontus; Reinhard, Linda; Andersson, Magnus; Lindahl, Erik; Fedosova, Natalya; Nissen, Poul

    2013-10-04

    The Na(+), K(+)-adenosine triphosphatase (ATPase) maintains the electrochemical gradients of Na(+) and K(+) across the plasma membrane--a prerequisite for electrical excitability and secondary transport. Hitherto, structural information has been limited to K(+)-bound or ouabain-blocked forms. We present the crystal structure of a Na(+)-bound Na(+), K(+)-ATPase as determined at 4.3 Å resolution. Compared with the K(+)-bound form, large conformational changes are observed in the α subunit whereas the β and γ subunit structures are maintained. The locations of the three Na(+) sites are indicated with the unique site III at the recently suggested IIIb, as further supported by electrophysiological studies on leak currents. Extracellular release of the third Na(+) from IIIb through IIIa, followed by exchange of Na(+) for K(+) at sites I and II, is suggested.

  10. Nanotechnology Review: Molecular Electronics to Molecular Motors

    Science.gov (United States)

    Srivastava, Deepak; Saini, Subhash (Technical Monitor)

    1998-01-01

    Reviewing the status of current approaches and future projections, as already published in scientific journals and books, the talk will summarize the direction in which computational and experimental nanotechnologies are progressing. Examples of nanotechnological approaches to the concepts of design and simulation of carbon nanotube based molecular electronic and mechanical devices will be presented. The concepts of nanotube based gears and motors will be discussed. The above is a non-technical review talk which covers long term precompetitive basic research in already published material that has been presented before many US scientific meeting audiences.

  11. Molecular dynamics study of the vaporization of an ionic drop

    Science.gov (United States)

    Galamba, N.

    2010-09-01

    The melting of a microcrystal in vacuum and subsequent vaporization of a drop of NaCl were studied through molecular dynamics simulations with the Born-Mayer-Huggins-Tosi-Fumi rigid-ion effective potential. The vaporization was studied for a single isochor at increasing temperatures until the drop completely vaporized, and gaseous NaCl formed. Examination of the vapor composition shows that the vapor of the ionic drop and gaseous NaCl are composed of neutral species, the most abundant of which, ranging from simple NaCl monomers (ion pairs) to nonlinear polymers, (NanCln)n=2-4. The enthalpies of sublimation, vaporization, and dissociation of the different vapor species are found to be in reasonable agreement with available experimental data. The decrease of the enthalpy of vaporization of the vapor species, with the radius of the drop decrease, accounts for a larger fraction of trimers and tetramers than that inferred from experiments. Further, the rhombic dimer is significantly more abundant than its linear isomer although the latter increases with the temperature. The present results suggest that both trimers and linear dimers may be important to explain the vapor pressure of molten NaCl at temperatures above 1500 K.

  12. NaK handling and removal

    International Nuclear Information System (INIS)

    Desreumaux, J.; Rodriguez, G.; Guigon, A.; Verdelli, J.; Thomine, G.

    1997-01-01

    Sodium-potassium alloy is used in specific application in French Fast Breeder Reactors as: cold traps, NaK bubbler for argon purification, valves and also in experimental irradiation devices. lt has been preferred to sodium because it is liquid from + 7 deg. C for the most common peritectic alloy. After its use, NaK is considered as a hazardous waste (nuclear or not) due to its high reactivity with air and water. The most important risk remains in handling NaK systems which have not been operated for some time. The NaK will be covered with a crust of the superoxide K02 which is a strong oxidising agent. Thermodynamically, K02 will react with most organic material or metallic dust or swarfs and can also react with additional NaK to give sufficient heat to boil part of the NaK, resulting in a sudden increase in pressure and small explosions. We describe the formation given to experimenters in our Sodium School and the CEA's experience in treating specific devices for transportation, decanting of tanks, tank opening and NaK removal. (author)

  13. Dinâmica molecular ab initio:aplicações ao estudo de propriedades electrónicas de sistemas moleculares

    OpenAIRE

    Martiniano, Hugo Filipe de Mesquita Costa, 1978-

    2013-01-01

    Tese de doutoramento, Química (Química-Física), Universidade de Lisboa, Faculdade de Ciências, 2013 O método da dinâmica molecular ab initio exibe vantagens significativas para o estudo da estrutura e propriedades electrónicas de sistemas moleculares complexos. No entanto, uma das suas desvantagens é o elevado custo computacional, quando comparado com os métodos de dinâmica molecular clássicos. Um dos modos de resolver este problema é adoptar uma abordagem sequencial, na qual a dinâmica é ...

  14. Hydrothermal synthesis, structure and photocatalytic properties of La/Bi co-doped NaTaO3

    International Nuclear Information System (INIS)

    Lan, Nguyen Thi; Huan, Bui Doan; Anh, Trinh Xuan; Chinh, Huynh Dang; Phan, Le Gia; Hoang, Luc Huy; Hong, Le Van

    2016-01-01

    La/Bi co-doped NaTaO 3 nanomaterials for photocatalytic applications have been successfully synthesized by hydrothermal method at low temperature. The obtained materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and UV-Vis molecular absorption spectroscopy. The results showed that the particle sizes of La/Bi co-doped NaTaO 3 were smaller than that of the pure NaTaO 3 . La/Bi co-doping has extended optical absorption in the visible light region and then successfully increased photocatalytic activity of the La/Bi-codoped NaTaO 3 that were evaluated by degradation of methylene blue (MB). (author)

  15. Multicomponent diffusion in molten salt NaF-ZrF{sub 4}: Dynamical correlations and Maxwell–Stefan diffusivities

    Energy Technology Data Exchange (ETDEWEB)

    Baig, Mohammad Saad, E-mail: saad110baig@gmail.com; Chakraborty, Brahmananda; Ramaniah, Lavanya M. [High Pressure & Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai-85 (India)

    2016-05-23

    NaF-ZrF{sub 4} is used as a waste incinerator and as a coolant in Generation IV reactors.Structural and dynamical properties of molten NaF-ZrF{sub 4} system were studied along with Onsagercoefficients and Maxwell–Stefan (MS) Diffusivities applying Green–Kubo formalism and molecular dynamics (MD) simulations. The zirconium ions are found to be 8 fold coordinated with fluoride ions for all temperatures and concentrations. All the diffusive flux correlations show back-scattering. Even though the MS diffusivities are expected to depend very lightly on the composition because of decoupling of thermodynamic factor, the diffusivity Đ{sub Na-F} shows interesting behavior with the increase in concentration of ZrF{sub 4}. This is because of network formation in NaF-ZrF{sub 4}. Positive entropy constraints have been plotted to authenticate negative diffusivities observed.

  16. Na/K pump inactivation, subsarcolemmal Na measurements, and cytoplasmic ion turnover kinetics contradict restricted Na spaces in murine cardiac myocytes

    OpenAIRE

    Lu, Fang-Min; Hilgemann, Donald W.

    2017-01-01

    The Na/K pump exports cytoplasmic Na ions while importing K ions, and its activity is thought to be affected by restricted intracellular Na diffusion in cardiac myocytes. Lu and Hilgemann find instead that the pump can enter an inactivated state and that inactivation can be relieved by cytoplasmic Na.

  17. MODELI MERJENJA KAKOVOSTI STORITEV NA MEDORGANIZACIJSKEM TRGU

    OpenAIRE

    Cestnik, Dušan

    2011-01-01

    Vse večja konkurenca na medorganizacijskih trgih sili tako storitvena podjetja, kot tudi podjetja, ki tržijo izdelke, da svoje delo opravljajo vse bolj kakovostno na vseh ravneh svojega delovanja. Podjetja morajo svoje odjemalce obdržati, prav tako pa morajo delovati tudi na pridobivanju novih odjemalcev. Da pa podjetja svoje odjemalce obdržijo morajo nenehno delovati tako, da uživajo zaupanje svojih odjemalcev. Odjemalec že z odločitvijo za neko določeno podjetje XY pričakuje, da bodo storit...

  18. Na+,K+ pumpen vedbliver at overraske

    DEFF Research Database (Denmark)

    Vilsen, Bente

    2008-01-01

    This article provides an overview of news about the Na+,K+ pump, an indispensable enzyme whose protein structure has been described in a recent article in Nature, 50 years after its discovery. In combination with mutational analysis, the structure reveals the binding pocket for the K+ ions...... and the regulation of Na+ transport by a strategically located C-terminus of the protein. Focus is also on the pathophysiology of two neurological disorders, familial hemiplegic migraine and rapid-onset dystonia-parkinsonism, recently shown to be caused by mutations in the Na+,K+-ATPase. Udgivelsesdato: may 19...

  19. Myocardial Na,K-ATPase: Clinical aspects

    Science.gov (United States)

    Kjeldsen, Keld

    2003-01-01

    The specific binding of digitalis glycosides to Na,K-ATPase is used as a tool for Na,K-ATPase quantification with high accuracy and precision. In myocardial biopsies from patients with heart failure, total Na,K-ATPase concentration is decreased by around 40%; a correlation exists between a decrease in heart function and a decrease in Na,K-ATPase concentration. During digitalization, around 30% of remaining pumps are occupied by digoxin. Myocardial Na,K-ATPase is also influenced by other drugs used for the treatment of heart failure. Thus, potassium loss during diuretic therapy has been found to reduce myocardial Na,K-ATPase, whereas angiotensin-converting enzyme inhibitors may stimulate Na,K pump activity. Furthermore, hyperaldosteronism induced by heart failure has been found to decrease Na,K-ATPase activity. Accordingly, treatment with the aldosterone antagonist, spironolactone, may also influence Na,K-ATPase activity. The importance of Na,K pump modulation with heart disease, inhibition in digitalization and other effects of medication should be considered in the context of sodium, potassium and calcium regulation. It is recommended that digoxin be administered to heart failure patients who, after institution of mortality-reducing therapy, still have heart failure symptoms, and that the therapy be continued if symptoms are revealed or reduced. Digitalis glycosides are the only safe inotropic drugs for oral use that improve hemodynamics in heart failure. An important aspect of myocardial Na,K pump affection in heart disease is its influence on extracellular potassium (Ke) homeostasis. Two important aspects should be considered: potassium handling among myocytes, and effects of potassium entering the extracellular space of the heart via the bloodstream. It should be noted that both of these aspects of Ke homeostasis are affected by regulatory aspects, eg, regulation of the Na,K pump by physiological and pathophysiological conditions, as well as by medical

  20. Nalaz tombusvirusa na vrsti Erigeron canadensis L.

    OpenAIRE

    Jeknić, Zoran; Erić, Živojin; Grbelja, Julijana

    1988-01-01

    Iz listova zaraženih primjeraka korovne biljke Erigeron canadensis L. koji su rasli na nekoliko lokaliteta u Sarajevu izoliran je virus iz skupine tombusvirusi. Identifikacija virusa izvršena je na osnovi reakcije pokusnih biljaka, analize ultratankih presjeka kroz zaraženo tkivo, morfologije i veličine virusnih čestica, te na osnovi seroloških reakcija metodom dvostruke imunodifuzije u agarskom gelu i čvrsto fazne imunoelektronske mikroskopije (SPIEM). U serološkim pokusima upotrijebljen je ...

  1. Selectivity of externally facing ion-binding sites in the Na/K pump to alkali metals and organic cations.

    Science.gov (United States)

    Ratheal, Ian M; Virgin, Gail K; Yu, Haibo; Roux, Benoît; Gatto, Craig; Artigas, Pablo

    2010-10-26

    The Na/K pump is a P-type ATPase that exchanges three intracellular Na(+) ions for two extracellular K(+) ions through the plasmalemma of nearly all animal cells. The mechanisms involved in cation selection by the pump's ion-binding sites (site I and site II bind either Na(+) or K(+); site III binds only Na(+)) are poorly understood. We studied cation selectivity by outward-facing sites (high K(+) affinity) of Na/K pumps expressed in Xenopus oocytes, under voltage clamp. Guanidinium(+), methylguanidinium(+), and aminoguanidinium(+) produced two phenomena possibly reflecting actions at site III: (i) voltage-dependent inhibition (VDI) of outwardly directed pump current at saturating K(+), and (ii) induction of pump-mediated, guanidinium-derivative-carried inward current at negative potentials without Na(+) and K(+). In contrast, formamidinium(+) and acetamidinium(+) induced K(+)-like outward currents. Measurement of ouabain-sensitive ATPase activity and radiolabeled cation uptake confirmed that these cations are external K(+) congeners. Molecular dynamics simulations indicate that bound organic cations induce minor distortion of the binding sites. Among tested metals, only Li(+) induced Na(+)-like VDI, whereas all metals tested except Na(+) induced K(+)-like outward currents. Pump-mediated K(+)-like organic cation transport challenges the concept of rigid structural models in which ion specificity at site I and site II arises from a precise and unique arrangement of coordinating ligands. Furthermore, actions by guanidinium(+) derivatives suggest that Na(+) binds to site III in a hydrated form and that the inward current observed without external Na(+) and K(+) represents cation transport when normal occlusion at sites I and II is impaired. These results provide insights on external ion selectivity at the three binding sites.

  2. Direct interaction of beta-amyloid with Na,K-ATPase as a putative regulator of the enzyme function

    Science.gov (United States)

    Petrushanko, Irina Yu.; Mitkevich, Vladimir A.; Anashkina, Anastasia A.; Adzhubei, Alexei A.; Burnysheva, Ksenia M.; Lakunina, Valentina A.; Kamanina, Yulia V.; Dergousova, Elena A.; Lopina, Olga D.; Ogunshola, Omolara O.; Bogdanova, Anna Yu.; Makarov, Alexander A.

    2016-06-01

    By maintaining the Na+ and K+ transmembrane gradient mammalian Na,K-ATPase acts as a key regulator of neuronal electrotonic properties. Na,K-ATPase has an important role in synaptic transmission and memory formation. Accumulation of beta-amyloid (Aβ) at the early stages of Alzheimer’s disease is accompanied by reduction of Na,K-ATPase functional activity. The molecular mechanism behind this phenomenon is not known. Here we show that the monomeric Aβ(1-42) forms a tight (Kd of 3 μM), enthalpy-driven equimolar complex with α1β1 Na,K-ATPase. The complex formation results in dose-dependent inhibition of the enzyme hydrolytic activity. The binding site of Aβ(1-42) is localized in the “gap” between the alpha- and beta-subunits of Na,K-ATPase, disrupting the enzyme functionality by preventing the subunits from shifting towards each other. Interaction of Na,K-ATPase with exogenous Aβ(1-42) leads to a pronounced decrease of the enzyme transport and hydrolytic activity and Src-kinase activation in neuroblastoma cells SH-SY5Y. This interaction allows regulation of Na,K-ATPase activity by short-term increase of the Aβ(1-42) level. However prolonged increase of Aβ(1-42) level under pathological conditions could lead to chronical inhibition of Na,K-ATPase and disruption of neuronal function. Taken together, our data suggest the role of beta-amyloid as a novel physiological regulator of Na,K-ATPase.

  3. Mechanism of Na,K-ATPase decline during sheep red cell maturation

    International Nuclear Information System (INIS)

    Grafova, E.; Blostein, R.

    1987-01-01

    Na,K-ATPase of immature and mature sheep red cells of both the high-K + and low-K + genotypes as well as cells of both types matured in vitro was detected using polyclonal antiserum to sheep kidney Na,K-ATPase. Following SDS-PAGE and immunoblotting, the major reactive component was the ∼ 100 kDa catalytic α subunit. A less prominent band migrating as a sharper, lower molecular weight (50 kDa) component than the kidney Na,K-ATPase β subunit is apparent in reticulocytes but not mature cells. Membranes from both genotypes showed identical immunologically reactive peptides, except for the lower intensity of the α subunit in the mature cells of the low- compared to high-K + sheep. Following culture of both types, moderate reduction in reactivity was apparent. Immunologically reactive α subunit as well as the 50 kDa species were detected in membranous material shed into the culture medium. This material was functionally inactive (lack of both [ 3 H] ouabain binding and Na + -dependent phosphorylation of Na,K-ATPase). The existence in reticulocytes of an intracellular pool of ouabain binding sites is evidenced in appearance of extra sites following rapid ATP depletion and also after addition of chloroquine. Taken together, these findings are consistent with a maturation-associated decrease of sodium pumps by a process of membrane recycling, processing and, to some extent, exocytosis

  4. Mechanism of Na,K-ATPase decline during sheep red cell maturation

    Energy Technology Data Exchange (ETDEWEB)

    Grafova, E.; Blostein, R.

    1987-05-01

    Na,K-ATPase of immature and mature sheep red cells of both the high-K/sup +/ and low-K/sup +/ genotypes as well as cells of both types matured in vitro was detected using polyclonal antiserum to sheep kidney Na,K-ATPase. Following SDS-PAGE and immunoblotting, the major reactive component was the approx. 100 kDa catalytic ..cap alpha.. subunit. A less prominent band migrating as a sharper, lower molecular weight (50 kDa) component than the kidney Na,K-ATPase ..beta.. subunit is apparent in reticulocytes but not mature cells. Membranes from both genotypes showed identical immunologically reactive peptides, except for the lower intensity of the ..cap alpha.. subunit in the mature cells of the low- compared to high-K/sup +/ sheep. Following culture of both types, moderate reduction in reactivity was apparent. Immunologically reactive ..cap alpha.. subunit as well as the 50 kDa species were detected in membranous material shed into the culture medium. This material was functionally inactive (lack of both (/sup 3/H) ouabain binding and Na/sup +/-dependent phosphorylation of Na,K-ATPase). The existence in reticulocytes of an intracellular pool of ouabain binding sites is evidenced in appearance of extra sites following rapid ATP depletion and also after addition of chloroquine. Taken together, these findings are consistent with a maturation-associated decrease of sodium pumps by a process of membrane recycling, processing and, to some extent, exocytosis.

  5. The initial stages of NaCl dissolution: Ion or ion pair solvation?

    Science.gov (United States)

    Klimes, Jiri; Michaelides, Angelos

    2009-03-01

    The interaction of water with rock salt (NaCl) is important in a wide variety of natural processes and human activities. A lot is known about NaCl dissolution at the macroscopic level but we do not yet have a detailed atomic scale picture of how salt crystals dissolve. Here we report an extensive series of density functional theory, forcefield and molecular dynamics studies of water clusters at flat and defective NaCl surfaces and NaCl clusters. The focus is on answering seemingly elementary questions such as how many water molecules are needed before it becomes favorable to extract an ion or a pair of ions from the crystal or the cluster. It turns out, however, that the answers to these questions are not so straightforward: below a certain number of water molecules (˜ 12) solvation of individual ions is less costly and above this number solvation of ion pairs is favored. These results reveal a hitherto unknown complexity in the NaCl dissolution process born out of a subtle interplay between water-water and water-ion interactions.

  6. Molecular dewetting on insulators

    International Nuclear Information System (INIS)

    Burke, S A; Topple, J M; Gruetter, P

    2009-01-01

    Recent attention given to the growth and morphology of organic thin films with regard to organic electronics has led to the observation of dewetting (a transition from layer(s) to islands) of molecular deposits in many of these systems. Dewetting is a much studied phenomenon in the formation of polymer and liquid films, but its observation in thin films of the 'small' molecules typical of organic electronics requires additional consideration of the structure of the interface between the molecular film and the substrate. This review covers some key concepts related to dewetting and molecular film growth. In particular, the origins of different growth modes and the thickness dependent interactions which give rise to dewetting are discussed in terms of surface energies and the disjoining pressure. Characteristics of molecular systems which may lead to these conditions, including the formation of metastable interface structures and commensurate-incommensurate phase transitions, are also discussed. Brief descriptions of some experimental techniques which have been used to study molecular dewetting are given as well. Examples of molecule-on-insulator systems which undergo dewetting are described in some detail, specifically perylene derivatives on alkali halides, C 60 on alkali halides, and the technologically important system of pentacene on SiO 2 . These examples point to some possible predicting factors for the occurrence of dewetting, most importantly the formation of an interface layer which differs from the bulk crystal structure. (topical review)

  7. Molecular dewetting on insulators.

    Science.gov (United States)

    Burke, S A; Topple, J M; Grütter, P

    2009-10-21

    Recent attention given to the growth and morphology of organic thin films with regard to organic electronics has led to the observation of dewetting (a transition from layer(s) to islands) of molecular deposits in many of these systems. Dewetting is a much studied phenomenon in the formation of polymer and liquid films, but its observation in thin films of the 'small' molecules typical of organic electronics requires additional consideration of the structure of the interface between the molecular film and the substrate. This review covers some key concepts related to dewetting and molecular film growth. In particular, the origins of different growth modes and the thickness dependent interactions which give rise to dewetting are discussed in terms of surface energies and the disjoining pressure. Characteristics of molecular systems which may lead to these conditions, including the formation of metastable interface structures and commensurate-incommensurate phase transitions, are also discussed. Brief descriptions of some experimental techniques which have been used to study molecular dewetting are given as well. Examples of molecule-on-insulator systems which undergo dewetting are described in some detail, specifically perylene derivatives on alkali halides, C(60) on alkali halides, and the technologically important system of pentacene on SiO(2). These examples point to some possible predicting factors for the occurrence of dewetting, most importantly the formation of an interface layer which differs from the bulk crystal structure.

  8. Phylogenetic molecular function annotation

    International Nuclear Information System (INIS)

    Engelhardt, Barbara E; Jordan, Michael I; Repo, Susanna T; Brenner, Steven E

    2009-01-01

    It is now easier to discover thousands of protein sequences in a new microbial genome than it is to biochemically characterize the specific activity of a single protein of unknown function. The molecular functions of protein sequences have typically been predicted using homology-based computational methods, which rely on the principle that homologous proteins share a similar function. However, some protein families include groups of proteins with different molecular functions. A phylogenetic approach for predicting molecular function (sometimes called 'phylogenomics') is an effective means to predict protein molecular function. These methods incorporate functional evidence from all members of a family that have functional characterizations using the evolutionary history of the protein family to make robust predictions for the uncharacterized proteins. However, they are often difficult to apply on a genome-wide scale because of the time-consuming step of reconstructing the phylogenies of each protein to be annotated. Our automated approach for function annotation using phylogeny, the SIFTER (Statistical Inference of Function Through Evolutionary Relationships) methodology, uses a statistical graphical model to compute the probabilities of molecular functions for unannotated proteins. Our benchmark tests showed that SIFTER provides accurate functional predictions on various protein families, outperforming other available methods.

  9. Molecular MR imaging

    International Nuclear Information System (INIS)

    Fleige, G.; Hamm, B.

    2000-01-01

    Basic medicobiological research in recent years has made rapid advances in the functional understanding of normal and pathological processes down to the molecular level. At the same time, various imaging modalities have developed from the depiction of organs to approaching the depiction of the cellular level and are about to make the visualization of molecular processes an established procedure. Besides other modalities like PET and near-infrared fluorescence, MR imaging offers some promising options for molecular imaging as well as some applications that have already been tested such as the visualization of enzyme activity, the depiction of the expression of certain genes, the visualization of surface receptors, or the specific demonstration of cells involved in the body's immune response. A major advantage of molecular magnetic resonance imaging (mMRI) over other more sensitive modalities is its high spatial resolution. However, the establishment of mMRI crucially relies on further improvements in resolution and the development of molecular markers for improving its sensitivity and specificity. The state of the art of mMRI is presented by giving a survey of the literature on experimental studies and reporting the results our study group obtained during investigation on gliomas. (orig.) [de

  10. Molecularly targeted therapeutic radiopharmaceuticals

    International Nuclear Information System (INIS)

    Saw, M.M.

    2007-01-01

    Full text: It is generally agreed that current focus of nuclear medicine development should be on molecular imaging and therapy. Though, the widespread use of the terminology 'molecular imaging' is quite recent, nuclear medicine has used molecular imaging techniques for more than 20 years ago. A variety of radiopharmaceuticals have been introduced for the internal therapy of malignant and inflammatory lesions in nuclear medicine. In the field of bio/medical imaging, nuclear medicine is one of the disciplines which has the privilege of organized and well developed chemistry/ pharmacy section; radio-chemistry/radiopharmacy. Fundamental principles have been developed more than 40 years ago and advanced research is going well into postgenomic era. The genomic revolution and dramatically increased insight in the molecular mechanisms underlying pathology have led to paradigm shift in drug development. Likewise does in the nuclear medicine. Here, the author will present current clinical and pre-clinical therapeutic radiopharmaceuticals based on molecular targets such as membrane-bound receptors, enzymes, nucleic acids, sodium iodide symporter, etc, in correlation with fundamentals of radiopharmacy. (author)

  11. Glutathionylation-Dependence of Na+-K+-Pump Currents Can Mimic Reduced Subsarcolemmal Na+ Diffusion

    Science.gov (United States)

    Garcia, Alvaro; Liu, Chia-Chi; Cornelius, Flemming; Clarke, Ronald J.; Rasmussen, Helge H.

    2016-01-01

    The existence of a subsarcolemmal space with restricted diffusion for Na+ in cardiac myocytes has been inferred from a transient peak electrogenic Na+-K+ pump current beyond steady state on reexposure of myocytes to K+ after a period of exposure to K+-free extracellular solution. The transient peak current is attributed to enhanced electrogenic pumping of Na+ that accumulated in the diffusion-restricted space during pump inhibition in K+-free extracellular solution. However, there are no known physical barriers that account for such restricted Na+ diffusion, and we examined if changes of activity of the Na+-K+ pump itself cause the transient peak current. Reexposure to K+ reproduced a transient current beyond steady state in voltage-clamped ventricular myocytes as reported by others. Persistence of it when the Na+ concentration in patch pipette solutions perfusing the intracellular compartment was high and elimination of it with K+-free pipette solution could not be reconciled with restricted subsarcolemmal Na+ diffusion. The pattern of the transient current early after pump activation was dependent on transmembrane Na+- and K+ concentration gradients suggesting the currents were related to the conformational poise imposed on the pump. We examined if the currents might be accounted for by changes in glutathionylation of the β1 Na+-K+ pump subunit, a reversible oxidative modification that inhibits the pump. Susceptibility of the β1 subunit to glutathionylation depends on the conformational poise of the Na+-K+ pump, and glutathionylation with the pump stabilized in conformations equivalent to those expected to be imposed on voltage-clamped myocytes supported this hypothesis. So did elimination of the transient K+-induced peak Na+-K+ pump current when we included glutaredoxin 1 in patch pipette solutions to reverse glutathionylation. We conclude that transient K+-induced peak Na+-K+ pump current reflects the effect of conformation-dependent β1 pump subunit

  12. Efeitos da suplementação de creatina na captação de glicose em ratos submetidos ao exercício físico Effects of creatine supplementation on glucose uptake in rats submitted to exercise training

    Directory of Open Access Journals (Sweden)

    Thiago Onofre Freire

    2008-10-01

    Full Text Available Estudos recentes têm sugerido que a suplementação de creatina é capaz de modular a homeostase da glicose, aumentando sua captação pelos tecidos periféricos. O objetivo deste trabalho foi investigar o efeito da suplementação de creatina na tolerância à glicose e no conteúdo de glicogênio muscular e hepático em ratos submetidos ou não à atividade física por quatro e oito semanas. Ratos Wistar foram divididos em dois grupos: quatro e oito semanas de intervenção. Posteriormente, cada grupo foi subdividido em quatro subgrupos, de acordo com a ingestão do suplemento e o treinamento: controle cedentário, controle treinado, suplementado sedentário e suplementado treinado. Os animais tiveram livre acesso à água e ração; o grupo suplementado teve 2% de sua ração sob a forma de creatina monoidratada. Os grupos exercitados nadaram 40 minutos por dia, quatro dias por semana, com carga entre 2 e 5% do seu peso amarrado ao peito. Após quatro e oito semanas, o teste oral de tolerância à glicose e as dosagens de glicogênio muscular e hepático foram realizadas. Não foram observadas diferenças significativas entre os grupos no teste de tolerância oral à glicose e no conteúdo de glicogênio muscular e hepático. Este estudo mostrou que a suplementação de creatina não exerceu influência na tolerância à glicose nem nas concentrações de glicogênio em ratos submetidos ou não à atividade física por quatro ou oito semanas.Recently, studies have suggested that creatine supplementation can modulate glucose homeostasis by increasing glucose uptake in peripheral tissues. The aim of this study was to investigate the effects of creatine supplementation on glucose tolerance, muscle and hepatic glycogen content in rats submitted or not to physical activity for four and eight weeks. Wistar rats were divided in two groups: four and eight weeks of intervention. Afterwards, each group was subdivided in four subgroups, according to

  13. Active ingredients in Chinese medicines promoting blood circulation as Na+/K+ -ATPase inhibitors.

    Science.gov (United States)

    Chen, Ronald J Y; Jinn, Tzyy-rong; Chen, Yi-ching; Chung, Tse-yu; Yang, Wei-hung; Tzen, Jason T C

    2011-02-01

    The positive inotropic effect of cardiac glycosides lies in their reversible inhibition on the membrane-bound Na(+)/K(+)-ATPase in human myocardium. Steroid-like compounds containing a core structure similar to cardiac glycosides are found in many Chinese medicines conventionally used for promoting blood circulation. Some of them are demonstrated to be Na(+)/K(+)-ATPase inhibitors and thus putatively responsible for their therapeutic effects via the same molecular mechanism as cardiac glycosides. On the other hand, magnesium lithospermate B of danshen is also proposed to exert its cardiac therapeutic effect by effectively inhibiting Na(+)/K(+)-ATPase. Theoretical modeling suggests that the number of hydrogen bonds and the strength of hydrophobic interaction between the effective ingredients of various medicines and residues around the binding pocket of Na(+)/K(+)-ATPase are crucial for the inhibitory potency of these active ingredients. Ginsenosides, the active ingredients in ginseng and sanqi, substantially inhibit Na(+)/K(+)-ATPase when sugar moieties are attached only to the C-3 position of their steroid-like structure, equivalent to the sugar position in cardiac glycosides. Their inhibitory potency is abolished, however, when sugar moieties are linked to C-6 or C-20 position of the steroid nucleus; presumably, these sugar attachments lead to steric hindrance for the entrance of ginsenosides into the binding pocket of Na(+)/K(+)-ATPase. Neuroprotective effects of cardiac glycosides, several steroid-like compounds, and magnesium lithospermate B against ischemic stroke have been accordingly observed in a cortical brain slice-based assay model, and cumulative data support that effective inhibitors of Na(+)/K(+)-ATPase in the brain could be potential drugs for the treatment of ischemic stroke.

  14. Sodium recognition by the Na+/Ca2+ exchanger in the outward-facing conformation.

    Science.gov (United States)

    Marinelli, Fabrizio; Almagor, Lior; Hiller, Reuben; Giladi, Moshe; Khananshvili, Daniel; Faraldo-Gómez, José D

    2014-12-16

    Na(+)/Ca(2+) exchangers (NCXs) are ubiquitous membrane transporters with a key role in Ca(2+) homeostasis and signaling. NCXs mediate the bidirectional translocation of either Na(+) or Ca(2+), and thus can catalyze uphill Ca(2+) transport driven by a Na(+) gradient, or vice versa. In a major breakthrough, a prokaryotic NCX homolog (NCX_Mj) was recently isolated and its crystal structure determined at atomic resolution. The structure revealed an intriguing architecture consisting of two inverted-topology repeats, each comprising five transmembrane helices. These repeats adopt asymmetric conformations, yielding an outward-facing occluded state. The crystal structure also revealed four putative ion-binding sites, but the occupancy and specificity thereof could not be conclusively established. Here, we use molecular-dynamics simulations and free-energy calculations to identify the ion configuration that best corresponds to the crystallographic data and that is also thermodynamically optimal. In this most probable configuration, three Na(+) ions occupy the so-called Sext, SCa, and Sint sites, whereas the Smid site is occupied by one water molecule and one H(+), which protonates an adjacent aspartate side chain (D240). Experimental measurements of Na(+)/Ca(2+) and Ca(2+)/Ca(2+) exchange by wild-type and mutagenized NCX_Mj confirm that transport of both Na(+) and Ca(2+) requires protonation of D240, and that this side chain does not coordinate either ion at Smid. These results imply that the ion exchange stoichiometry of NCX_Mj is 3:1 and that translocation of Na(+) across the membrane is electrogenic, whereas transport of Ca(2+) is not. Altogether, these findings provide the basis for further experimental and computational studies of the conformational mechanism of this exchanger.

  15. Protonation of key acidic residues is critical for the K⁺-selectivity of the Na/K pump.

    Science.gov (United States)

    Yu, Haibo; Ratheal, Ian M; Artigas, Pablo; Roux, Benoît

    2011-09-11

    The sodium-potassium (Na/K) pump is a P-type ATPase that generates Na(+) and K(+) concentration gradients across the cell membrane. For each hydrolyzed ATP molecule, the pump extrudes three Na(+) and imports two K(+) by alternating between outward- and inward-facing conformations that preferentially bind K(+) or Na(+), respectively. Remarkably, the selective K(+) and Na(+) binding sites share several residues, and how the pump is able to achieve the selectivity required for the functional cycle is unclear. Here, free energy-perturbation molecular dynamics (FEP/MD) simulations based on the crystal structures of the Na/K pump in a K(+)-loaded state (E2·P(i)) reveal that protonation of the high-field acidic side chains involved in the binding sites is crucial to achieving the proper K(+) selectivity. This prediction is tested with electrophysiological experiments showing that the selectivity of the E2P state for K(+) over Na(+) is affected by extracellular pH.

  16. Ankyrin-B coordinates the Na/K ATPase, Na/Ca exchanger, and InsP3 receptor in a cardiac T-tubule/SR microdomain.

    Directory of Open Access Journals (Sweden)

    2005-12-01

    Full Text Available We report identification of an ankyrin-B-based macromolecular complex of Na/K ATPase (alpha 1 and alpha 2 isoforms, Na/Ca exchanger 1, and InsP3 receptor that is localized in cardiomyocyte T-tubules in discrete microdomains distinct from classic dihydropyridine receptor/ryanodine receptor "dyads." E1425G mutation of ankyrin-B, which causes human cardiac arrhythmia, also blocks binding of ankyrin-B to all three components of the complex. The ankyrin-B complex is markedly reduced in adult ankyrin-B(+/- cardiomyocytes, which may explain elevated [Ca2+]i transients in these cells. Thus, loss of the ankyrin-B complex provides a molecular basis for cardiac arrhythmia in humans and mice. T-tubule-associated ankyrin-B, Na/Ca exchanger, and Na/K ATPase are not present in skeletal muscle, where ankyrin-B is expressed at 10-fold lower levels than in heart. Ankyrin-B also is not abundantly expressed in smooth muscle. We propose that the ankyrin-B-based complex is a specialized adaptation of cardiomyocytes with a role for cytosolic Ca2+ modulation.

  17. Evolutionary molecular medicine.

    Science.gov (United States)

    Nesse, Randolph M; Ganten, Detlev; Gregory, T Ryan; Omenn, Gilbert S

    2012-05-01

    Evolution has long provided a foundation for population genetics, but some major advances in evolutionary biology from the twentieth century that provide foundations for evolutionary medicine are only now being applied in molecular medicine. They include the need for both proximate and evolutionary explanations, kin selection, evolutionary models for cooperation, competition between alleles, co-evolution, and new strategies for tracing phylogenies and identifying signals of selection. Recent advances in genomics are transforming evolutionary biology in ways that create even more opportunities for progress at its interfaces with genetics, medicine, and public health. This article reviews 15 evolutionary principles and their applications in molecular medicine in hopes that readers will use them and related principles to speed the development of evolutionary molecular medicine.

  18. [Molecular techniques in mycology].

    Science.gov (United States)

    Rodríguez-Tudela, Juan Luis; Cuesta, Isabel; Gómez-López, Alicia; Alastruey-Izquierdo, Ana; Bernal-Martínez, Leticia; Cuenca-Estrella, Manuel

    2008-11-01

    An increasing number of molecular techniques for the diagnosis of fungal infections have been developed in the last few years, due to the growing prevalence of mycoses and the length of time required for diagnosis when classical microbiological methods are used. These methods are designed to resolve the following aspects of mycological diagnosis: a) Identification of fungi to species level by means of sequencing relevant taxonomic targets; b) early clinical diagnosis of invasive fungal infections; c) detection of molecular mechanisms of resistance to antifungal agents; and d) molecular typing of fungi. Currently, these methods are restricted to highly developed laboratories. However, some of these techniques will probably be available in daily clinical practice in the near future.

  19. Theoretical Molecular Biophysics

    CERN Document Server

    Scherer, Philipp

    2010-01-01

    "Theoretical Molecular Biophysics" is an advanced study book for students, shortly before or after completing undergraduate studies, in physics, chemistry or biology. It provides the tools for an understanding of elementary processes in biology, such as photosynthesis on a molecular level. A basic knowledge in mechanics, electrostatics, quantum theory and statistical physics is desirable. The reader will be exposed to basic concepts in modern biophysics such as entropic forces, phase separation, potentials of mean force, proton and electron transfer, heterogeneous reactions coherent and incoherent energy transfer as well as molecular motors. Basic concepts such as phase transitions of biopolymers, electrostatics, protonation equilibria, ion transport, radiationless transitions as well as energy- and electron transfer are discussed within the frame of simple models.

  20. Molecular Diagnosis of Tuberculosis.

    Science.gov (United States)

    Nurwidya, Fariz; Handayani, Diah; Burhan, Erlina; Yunus, Faisal

    2018-01-01

    Tuberculosis (TB) is one of the leading causes of adult death in the Asia-Pacific Region, including Indonesia. As an infectious disease caused by Mycobacterium tuberculosis (MTB), TB remains a major public health issue especially in developing nations due to the lack of adequate diagnostic testing facilities. Diagnosis of TB has entered an era of molecular detection that provides faster and more cost-effective methods to diagnose and confirm drug resistance in TB cases, meanwhile, diagnosis by conventional culture systems requires several weeks. New advances in the molecular detection of TB, including the faster and simpler nucleic acid amplification test (NAAT) and whole-genome sequencing (WGS), have resulted in a shorter time for diagnosis and, therefore, faster TB treatments. In this review, we explored the current findings on molecular diagnosis of TB and drug-resistant TB to see how this advancement could be integrated into public health systems in order to control TB.

  1. Altered Na+ transport after an intracellular alpha-subunit deletion reveals strict external sequential release of Na+ from the Na/K pump.

    Science.gov (United States)

    Yaragatupalli, Siddhartha; Olivera, J Fernando; Gatto, Craig; Artigas, Pablo

    2009-09-08

    The Na/K pump actively exports 3 Na(+) in exchange for 2 K(+) across the plasmalemma of animal cells. As in other P-type ATPases, pump function is more effective when the relative affinity for transported ions is altered as the ion binding sites alternate between opposite sides of the membrane. Deletion of the five C-terminal residues from the alpha-subunit diminishes internal Na(+) (Na(i)(+)) affinity approximately 25-fold [Morth et al. (2007) Nature 450:1043-1049]. Because external Na(+) (Na(o)(+)) binding is voltage-dependent, we studied the reactions involving this process by using two-electrode and inside-out patch voltage clamp in normal and truncated (DeltaKESYY) Xenopus-alpha1 pumps expressed in oocytes. We observed that DeltaKESYY (i) decreased both Na(o)(+) and Na(i)(+) apparent affinities in the absence of K(o)(+), and (ii) did not affect apparent Na(o)(+) affinity at high K(o)(+). These results support a model of strict sequential external release of Na(+) ions, where the Na(+)-exclusive site releases Na(+) before the sites shared with K(+) and the DeltaKESYY deletion only reduces Na(o)(+) affinity at the shared sites. Moreover, at nonsaturating K(o)(+), DeltaKESYY induced an inward flow of Na(+) through Na/K pumps at negative potentials. Guanidinium(+) can also permeate truncated pumps, whereas N-methyl-D-glucamine cannot. Because guanidinium(o)(+) can also traverse normal Na/K pumps in the absence of both Na(o)(+) and K(o)(+) and can also inhibit Na/K pump currents in a Na(+)-like voltage-dependent manner, we conclude that the normal pathway transited by the first externally released Na(+) is large enough to accommodate guanidinium(+).

  2. Hydration effect on the electronic transport properties of oligomeric phenylene ethynylene molecular junctions

    International Nuclear Information System (INIS)

    Zong-Liang, Li; Huai-Zhi, Li; Yong, Ma; Guang-Ping, Zhang; Chuan-Kui, Wang

    2010-01-01

    A first-principles computational method based on the hybrid density functional theory is developed to simulate the electronic transport properties of oligomeric phenylene ethynylene molecular junctions with H 2 O molecules accumulated in the vicinity as recently reported by Na et al. [Nanotechnology 18 424001 (2007)]. The numerical results show that the hydrogen bonds between the oxygen atoms of the oligomeric phenylene ethynylene molecule and H 2 O molecules result in the localisation of the molecular orbitals and lead to the lower transition peaks. The H 2 O molecular chains accumulated in the vicinity of the molecular junction can not only change the electronic structure of the molecular junctions, but also open additional electronic transport pathways. The obvious influence of H 2 O molecules on the electronic structure of the molecular junction and its electronic transport properties is thus demonstrated. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  3. Erythrocyte 22Na+ influx in hypertension

    International Nuclear Information System (INIS)

    Shalev, O.; Eaton, J.W.; Ben-Ishay, D.

    1984-01-01

    We assessed 22Na+ uptake by erythrocytes (RBC) from 38 individuals with essential hypertension and 37 healthy controls. All subjects were male, white, non-obese and with normal renal function, obviating sex, race, hormonal, ponderal and renal factors known to influence RBC Na+ handling. The mean +/- sem 22Na+ uptake of the patients was 284 +/- 16 mumole/liter RBC/hour while that of normal controls was 249 +/- 11 mumole/liter RBC/hour; although the difference reached borderline significance, individual values showed considerable overlap. Consequently, in our population, RBC 22Na+ uptake is not a reliable marker for essential hypertension. We believe that previous studies should be reassessed with regard to patients' characteristics and future studies employ rigorous criteria in selection of subjects

  4. Painful Na-channelopathies: an expanding universe.

    Science.gov (United States)

    Waxman, Stephen G

    2013-07-01

    The universe of painful Na-channelopathies--human disorders caused by mutations in voltage-gated sodium channels--has recently expanded in three dimensions. We now know that mutations of sodium channels cause not only rare genetic 'model disorders' such as inherited erythromelalgia and channelopathy-associated insensitivity to pain but also common painful neuropathies. We have learned that mutations of NaV1.8, as well as mutations of NaV1.7, can cause painful Na-channelopathies. Moreover, recent studies combining atomic level structural models and pharmacogenomics suggest that the goal of genomically guided pain therapy may not be unrealistic. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Usmerjanje urbanega razvoja na mestni ravni

    Directory of Open Access Journals (Sweden)

    Mojca Šašek Divjak

    1999-01-01

    Full Text Available Kot je poudarjeno v predstavljenem načrtu Kopenhagna, mestni načrt ne more rešiti vseh planskih problemov mesta. Predstavljal naj bi predvideni red, ki pa se pogosto sproti podira glede na nepredvidena dogajanja v prostoru. Probleme je velikokrat treba reševati šele, ko se pokažejo. Zato mora biti mestni načrt zastavljen dovolj prilagodljivo in fleksibilno, da dovoljuje potrebne spremembe. Vendar mora kljub temu dati mestu trdne glavne usmeritve in s tem omogočiti, da meščani lahko izkoristijo priložnosti, ki jih nudi nova doba in uveljavljajo nove kvalitete bivanja.

  6. Angular momentum alignment in molecular beam scattering

    International Nuclear Information System (INIS)

    Treffers, M.A.

    1985-01-01

    It is shown how the angular momentum alignment in a molecular beam can be determined using laser-induced fluorescence in combination with precession of the angular momenta in a magnetic field. After a general analysis of the method, some results are presented to illustrate the possibilities of the method. Experimental data are presented on the alignment production for Na 2 molecules that made a collision induced angular momentum transition. Magnitude as well as direction of the alignment have been determined for scattering with several scattering partners and for a large number of scattering angles and transitions. The last chapter deals with the total alignment production in a final J-state, i.e. without state selection of the initial rotational state. (orig.)

  7. Synergetics of molecular systems

    CERN Document Server

    Lupichev, Lev N; Kadantsev, Vasiliy N

    2014-01-01

    Synergetics is the quantitative study of multicomponent systems that exhibit nonlinear dynamics and cooperativity. This book specifically considers basic models of the nonlinear dynamics of molecular systems and discusses relevant applications in biological physics and the polymer sciences.Emphasis is placed on specific solutions to the dynamical equations that correspond to the coherent formation of spatial-temporal structures, such as solitons, kinks and breathers, in particular. The emergence of these patterns in molecular structures provides a variety of information on their structural pro

  8. Molecular environmental geochemistry

    Science.gov (United States)

    O'Day, Peggy A.

    1999-05-01

    The chemistry, mobility, and bioavailability of contaminant species in the natural environment are controlled by reactions that occur in and among solid, aqueous, and gas phases. These reactions are varied and complex, involving changes in chemical form and mass transfer among inorganic, organic, and biochemical species. The field of molecular environmental geochemistry seeks to apply spectroscopic and microscopic probes to the mechanistic understanding of environmentally relevant chemical processes, particularly those involving contaminants and Earth materials. In general, empirical geochemical models have been shown to lack uniqueness and adequate predictive capability, even in relatively simple systems. Molecular geochemical tools, when coupled with macroscopic measurements, can provide the level of chemical detail required for the credible extrapolation of contaminant reactivity and bioavailability over ranges of temperature, pressure, and composition. This review focuses on recent advances in the understanding of molecular chemistry and reaction mechanisms at mineral surfaces and mineral-fluid interfaces spurred by the application of new spectroscopies and microscopies. These methods, such as synchrotron X-ray absorption and scattering techniques, vibrational and resonance spectroscopies, and scanning probe microscopies, provide direct chemical information that can elucidate molecular mechanisms, including element speciation, ligand coordination and oxidation state, structural arrangement and crystallinity on different scales, and physical morphology and topography of surfaces. Nonvacuum techniques that allow examination of reactions in situ (i.e., with water or fluids present) and in real time provide direct links between molecular structure and reactivity and measurements of kinetic rates or thermodynamic properties. Applications of these diverse probes to laboratory model systems have provided fundamental insight into inorganic and organic reactions at

  9. Molecular cardiovascular imaging

    International Nuclear Information System (INIS)

    Schaefers, M.

    2007-01-01

    Although huge and long-lasting research efforts have been spent on the development of new diagnostic techniques investigating cardiovascular diseases, still fundamental challenges exist; the main challenge being the diagnosis of a suspected or known coronary artery disease or its consequences (myocardial infarction, heart failure etc.). Beside morphological techniques, functional imaging modalities are available in clinical diagnostic algorithms, whereas molecular cardiovascular imaging techniques are still under development. This review summarizes clinical-diagnostical challenges of modern cardiovascular medicine as well as the potential of new molecular imaging techniques to face these. (orig.)

  10. Targeted molecular imaging

    International Nuclear Information System (INIS)

    Kim, E. Edmund

    2003-01-01

    Molecular imaging aims to visualize the cellular and molecular processes occurring in living tissues, and for the imaging of specific molecules in vivo, the development of reporter probes and dedicated imaging equipment is most important. Reporter genes can be used to monitor the delivery and magnitude of therapeutic gene transfer, and the time variation involved. Imaging technologies such as micro-PET, SPECT, MRI and CT, as well as optical imaging systems, are able to non-invasively detect, measure, and report the simultaneous expression of multiple meaningful genes. It is believed that recent advances in reporter probes, imaging technologies and gene transfer strategies will enhance the effectiveness of gene therapy trials

  11. Substructured multibody molecular dynamics.

    Energy Technology Data Exchange (ETDEWEB)

    Grest, Gary Stephen; Stevens, Mark Jackson; Plimpton, Steven James; Woolf, Thomas B. (Johns Hopkins University, Baltimore, MD); Lehoucq, Richard B.; Crozier, Paul Stewart; Ismail, Ahmed E.; Mukherjee, Rudranarayan M. (Rensselaer Polytechnic Institute, Troy, NY); Draganescu, Andrei I.

    2006-11-01

    We have enhanced our parallel molecular dynamics (MD) simulation software LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator, lammps.sandia.gov) to include many new features for accelerated simulation including articulated rigid body dynamics via coupling to the Rensselaer Polytechnic Institute code POEMS (Parallelizable Open-source Efficient Multibody Software). We use new features of the LAMMPS software package to investigate rhodopsin photoisomerization, and water model surface tension and capillary waves at the vapor-liquid interface. Finally, we motivate the recipes of MD for practitioners and researchers in numerical analysis and computational mechanics.

  12. Open source molecular modeling.

    Science.gov (United States)

    Pirhadi, Somayeh; Sunseri, Jocelyn; Koes, David Ryan

    2016-09-01

    The success of molecular modeling and computational chemistry efforts are, by definition, dependent on quality software applications. Open source software development provides many advantages to users of modeling applications, not the least of which is that the software is free and completely extendable. In this review we categorize, enumerate, and describe available open source software packages for molecular modeling and computational chemistry. An updated online version of this catalog can be found at https://opensourcemolecularmodeling.github.io. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  13. Molecular epidemiology of Blastocystis

    Directory of Open Access Journals (Sweden)

    Fadime Eroğlu

    2015-12-01

    Full Text Available Blastocystis pathogenicity and classification was newly illuminated with molecular genetic studies and recently the parasite was found in the focus of many researchers. Several molecular methods such as; polymerase chain reaction (PCR, PCR-restriction fragment length polymorphism, random amplified polymorphic DNA, real-time polymerase chain reaction and DNA sequencing analyses can be used in genotyping of Blastocystis. Blastocystis parasites may cause diarrhea, abdominal pain, bloating, gas, irritability, anorexia, cramps, vomiting, dehydration, insomnia, nausea, loss of appetite, weight loss, fatigue symptoms and also could be asymptomatic cases. In this review, it was aimed to summarize the associations between Blastocystis subtypes and pathogenicity.

  14. Valency and molecular structure

    CERN Document Server

    Cartmell, E

    1977-01-01

    Valency and Molecular Structure, Fourth Edition provides a comprehensive historical background and experimental foundations of theories and methods relating to valency and molecular structures. In this edition, the chapter on Bohr theory has been removed while some sections, such as structures of crystalline solids, have been expanded. Details of structures have also been revised and extended using the best available values for bond lengths and bond angles. Recent developments are mostly noted in the chapter on complex compounds, while a new chapter has been added to serve as an introduction t

  15. Ionic and Molecular Liquids

    DEFF Research Database (Denmark)

    Chaban, Vitaly V.; Prezhdo, Oleg

    2013-01-01

    Because of their outstanding versatility, room-temperature ionic liquids (RTILs) are utilized in an ever increasing number of novel and fascinating applications, making them the Holy Grail of modern materials science. In this Perspective, we address the fundamental research and prospective...... applications of RTILs in combination with molecular liquids, concentrating on three significant areas: (1) the use of molecular liquids to decrease the viscosity of RTILs; (2) the role of RTIL micelle formation in water and organic solvents; and (3) the ability of RTILs to adsorb pollutant gases. Current...

  16. Molecular confocal laser endomicroscopy

    DEFF Research Database (Denmark)

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

    2014-01-01

    While flexible endoscopy is essential for macroscopic evaluation, confocal laser endomicroscopy (CLE) has recently emerged as an endoscopic method enabling visualization at a cellular level. Two systems are currently available, one based on miniprobes that can be inserted via a conventional...... during on-going endoscopy), a novel world of molecular evaluation opens up. The method of molecular CLE could potentially be used for estimating the expression of important receptors in carcinomas, subsequently resulting in immediate individualization of treatment regimens, but also for improving...

  17. Na+-H+ exchange and Na+-dependent transport systems in streptozotocin diabetic rat kidneys

    International Nuclear Information System (INIS)

    El-Seifi, S.; Freiberg, J.M.; Kinsella, F.J.; Cheng, L.; Sacktor, B.

    1987-01-01

    The streptozotocin-induced diabetic rat was used to test the hypothesis that Na + -H + exchange activity in the proximal tubule luminal membrane would be increased in association with renal hypertrophy, altered glomerular hemodynamics, enhanced filtered load and tubular reabsorption of 22 Na + , and stimulated 22 Na= pump activity in the basolateral membrane, previously reported characteristics of this experimental animal model. Amiloride-sensitive H + gradient-dependent Na + uptake and Na + gradient-dependent H + flux were increased in brush-border membrane vesicles from the streptozotocin-treated animals. Na + gradient-dependent uptakes of phosphate, D-glucose, L-proline, and myoinositol were decreased in the drug-induced diabetic animals. These membrane transport alterations were not found when the streptozotocin-diabetic animals were treated with insulin

  18. MOLECULAR CLOUD CHEMISTRY AND THE IMPORTANCE OF DIELECTRONIC RECOMBINATION

    International Nuclear Information System (INIS)

    Bryans, P.; Kreckel, H.; Savin, D. W.; Roueff, E.; Wakelam, V.

    2009-01-01

    Dielectronic recombination (DR) of singly charged ions is a reaction pathway that is commonly neglected in chemical models of molecular clouds. In this study we include state-of-the-art DR data for He + , C + , N + , O + , Na + , and Mg + in chemical models used to simulate dense molecular clouds, protostars, and diffuse molecular clouds. We also update the radiative recombination (RR) rate coefficients for H + , He + , C + , N + , O + , Na + , and Mg + to the current state-of-the-art values. The new RR data have little effect on the models. However, the inclusion of DR results in significant differences in gas-grain models of dense, cold molecular clouds for the evolution of a number of surface and gas-phase species. We find differences of a factor of 2 in the abundance for 74 of the 655 species at times of 10 4 -10 6 yr in this model when we include DR. Of these 74 species, 16 have at least a factor of 10 difference in abundance. We find the largest differences for species formed on the surface of dust grains. These differences are due primarily to the addition of C + DR, which increases the neutral C abundance, thereby enhancing the accretion of C onto dust. These results may be important for the warm-up phase of molecular clouds when surface species are desorbed into the gas phase. We also note that no reliable state-of-the-art RR or DR data exist for Si + , P + , S + , Cl + , and Fe + . Modern calculations for these ions are needed to better constrain molecular cloud models.

  19. Molecular Simulation of Adsorption in Microporous Materials

    Directory of Open Access Journals (Sweden)

    Yiannourakou M.

    2013-11-01

    Full Text Available The development of industrial software, the decreasing cost of computing time, and the availability of well-tested forcefields make molecular simulation increasingly attractive for chemical engineers. We present here several applications of Monte-Carlo simulation techniques, applied to the adsorption of fluids in microporous solids such as zeolites and model carbons (pores < 2 nm. Adsorption was computed in the Grand Canonical ensemble with the MedeA®-GIBBS software, using energy grids to decrease computing time. MedeA®-GIBBS has been used for simulations in the NVT or NPT ensembles to obtain the density and fugacities of fluid phases. Simulation results are compared with experimental pure component isotherms in zeolites (hydrocarbon gases, water, alkanes, aromatics, ethanethiol, etc., and mixtures (methane-ethane, n-hexane-benzene, over a large range of temperatures. Hexane/benzene selectivity inversions between silicalite and Na-faujasites are well predicted with published forcefields, providing an insight on the underlying mechanisms. Also, the adsorption isotherms in Na-faujasites for light gases or ethane-thiol are well described. Regarding organic adsorbents, models of mature kerogen or coal were built in agreement with known chemistry of these systems. Obtaining realistic kerogen densities with the simple relaxation approach considered here is encouraging for the investigation of other organic systems. Computing excess sorption curves in qualitative agreement with those recently measured on dry samples of gas shale is also favorable. Although still preliminary, such applications illustrate the strength of molecular modeling in understanding complex systems in conditions where experiments are difficult.

  20. Effects of EDTA-Na (Na ethylenediaminetetraacetate) upon the metabolism of radiostrontium and radioyttrium in mice

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, T; Wakisaka, G; Kono, T; Hiroaki, A; Yamamasu, T; Sugawa, I

    1954-01-01

    The toxicity of EDTA-Na, inert Sr (NO/sub 3/)/sub 2/ and Ba (NO/sub 3/)/sub 2/ has been examined. Simultaneous injection of EDTA-Na showed no significant effect upon the distribution of radio-Sr in the bones of mice. The distribution of radio-Y in the bones of mice tended to decrease following the simultaneous subcutaneous injection of /sup 91/Y and EDTA-Na.

  1. Glutathionylation-Dependence of Na+-K+-Pump Currents Can Mimic Reduced Subsarcolemmal Na+ Diffusion

    OpenAIRE

    Garcia, Alvaro; Liu, Chia-Chi; Cornelius, Flemming; Clarke, Ronald?J.; Rasmussen, Helge?H.

    2016-01-01

    The existence of a subsarcolemmal space with restricted diffusion for Na+ in cardiac myocytes has been inferred from a transient peak electrogenic Na+-K+ pump current beyond steady state on reexposure of myocytes to K+ after a period of exposure to K+-free extracellular solution. The transient peak current is attributed to enhanced electrogenic pumping of Na+ that accumulated in the diffusion-restricted space during pump inhibition in K+-free extracellular solution. However, there are no know...

  2. General and specific lipid-protein interactions in Na,K-ATPase.

    Science.gov (United States)

    Cornelius, F; Habeck, M; Kanai, R; Toyoshima, C; Karlish, S J D

    2015-09-01

    The molecular activity of Na,K-ATPase and other P2 ATPases like Ca(2+)-ATPase is influenced by the lipid environment via both general (physical) and specific (chemical) interactions. Whereas the general effects of bilayer structure on membrane protein function are fairly well described and understood, the importance of the specific interactions has only been realized within the last decade due particularly to the growing field of membrane protein crystallization, which has shed new light on the molecular details of specific lipid-protein interactions. It is a remarkable observation that specific lipid-protein interactions seem to be evolutionarily conserved, and conformations of specifically bound lipids at the lipid-protein surface within the membrane are similar in crystal structures determined with different techniques and sources of the protein, despite the rather weak lipid-protein interaction energy. Studies of purified detergent-soluble recombinant αβ or αβFXYD Na,K-ATPase complexes reveal three separate functional effects of phospholipids and cholesterol with characteristic structural selectivity. The observations suggest that these three effects are exerted at separate binding sites for phophatidylserine/cholesterol (stabilizing), polyunsaturated phosphatidylethanolamine (stimulatory), and saturated PC or sphingomyelin/cholesterol (inhibitory), which may be located within three lipid-binding pockets identified in recent crystal structures of Na,K-ATPase. The findings point to a central role of direct and specific interactions of different phospholipids and cholesterol in determining both stability and molecular activity of Na,K-ATPase and possible implications for physiological regulation by membrane lipid composition. This article is part of a special issue titled "Lipid-Protein Interactions." Copyright © 2015 Elsevier B.V. All rights reserved.

  3. NA62 and NA48/2 results on search for Heavy Neutral Leptons

    Directory of Open Access Journals (Sweden)

    Lamanna Gianluca

    2018-01-01

    Full Text Available In this paper we present new results on upper limits for the search of Heavy Neutral Leptons (HNL with data collected by NA48/2 (2003-2004, NA62-RK (2007 and NA62 (2015 CERN experiments. The data collected with different trigger configuration allow to search for both long and short living heavy neutrinos in the mass range below the kaon mass. In addition the status of the search for K+ → π+vv with the NA62 detector will be briefly presented.

  4. Interaction between Na+/K+-pump and Na+/Ca2+-exchanger modulates intercellular communication.

    Science.gov (United States)

    Matchkov, Vladimir V; Gustafsson, Helena; Rahman, Awahan; Briggs Boedtkjer, Donna M; Gorintin, Sarah; Hansen, Anne Kirstine; Bouzinova, Elena V; Praetorius, Helle A; Aalkjaer, Christian; Nilsson, Holger

    2007-04-13

    Ouabain, a specific inhibitor of the Na(+)/K(+)-pump, has previously been shown to interfere with intercellular communication. Here we test the hypothesis that the communication between vascular smooth muscle cells is regulated through an interaction between the Na(+)/K(+)-pump and the Na(+)/Ca(2+)-exchanger leading to an increase in the intracellular calcium concentration ([Ca(2+)](i)) in discrete areas near the plasma membrane. [Ca(2+)](i) in smooth muscle cells was imaged in cultured rat aortic smooth muscle cell pairs (A7r5) and in rat mesenteric small artery segments simultaneously with force. In A7r5 coupling between cells was estimated by measuring membrane capacitance. Smooth muscle cells were uncoupled when the Na(+)/K(+)-pump was inhibited either by a low concentration of ouabain, which also caused a localized increase of [Ca(2+)](i) near the membrane, or by ATP depletion. Reduction of Na(+)/K(+)-pump activity by removal of extracellular potassium ([K(+)](o)) also uncoupled cells, but only after inhibition of K(ATP) channels. Inhibition of the Na(+)/Ca(2+)-exchange activity by SEA0400 or by a reduction of the equilibrium potential (making it more negative) also uncoupled the cells. Depletion of intracellular Na(+) and clamping of [Ca(2+)](i) at low concentrations prevented the uncoupling. The experiments suggest that the Na(+)/K(+)-pump may affect gap junction conductivity via localized changes in [Ca(2+)](i) through modulation of Na(+)/Ca(2+)-exchanger activity.

  5. Na5NbO5 and Na5TaO5 phases

    International Nuclear Information System (INIS)

    Darriet, J.; Maazaz, A.; Bouloux, J.C.; Delmas, C.

    1982-01-01

    New ternary oxides of formulas Na 5 NbO 5 and Na 5 TaO 5 have been prepared. They crystallize in the monoclinic system (space group C2/c). The crystal structure of Na 5 NbO 5 has been determined. It derives from a NaCl-type structure by ordering of the cations and of the oxygen vacancies in the anionic sublattice, the corresponding formula being Nasub(5/6)Nbsub(1/6)Osub(5/6)vacant sub(1/6). Sodium and niobium have a distorted square-pyramidal surrounding. (author)

  6. MOŽNOSTI VSTOPA NA TUJE TRGE NA PRIMERU PODJETJA AWOODTURE

    OpenAIRE

    Orličnik, Urša

    2014-01-01

    Danes pojavljanje podjetja samo na domačem trgu ni več dovolj. Spremembe okolja, naraščanje konkurence ter hiter tehnološki napredek, silijo podjetja k nenehnemu prilagajanju in iskanju novih priložnosti tako na domačem kot tudi na tujem trgu. Internacionalizacija podjetja tako postaja vedno bolj pomemembna za preživetje podjetja. Internacionalizacija se v najširšem smislu nanaša na vse oblike mednarodnega ekonomskega sodelovanja. Je dinamičen proces, kateremu nujno sledi sprememba stanja...

  7. Molecular theory of capillarity

    CERN Document Server

    Rowlinson, J S

    2002-01-01

    History of thought on molecular origins of surface phenomena offers a critical and detailed examination and assessment of modern theories, focusing on statistical mechanics and application of results in mean-field approximation to model systems. Emphasis on liquid-gas surface, with a focus on liquid-liquid surfaces in the final chapters. 1989 edition.

  8. Reviews: The Molecular Animator.

    Science.gov (United States)

    Journal of Chemical Education, 1987

    1987-01-01

    Provided is a review of a chemical software package. The package makes possible an instructional technique that is not effective by any other means, namely the ability to view molecular shapes in three dimensions. The program can be used with either IBM or Apple hardware. (RH)

  9. [Towards a molecular psychiatry].

    Science.gov (United States)

    de la Fuente, J R

    1988-06-01

    Recent research data from psychopharmacology, brain imaging and molecular genetics support the notion of a new psychiatric frontier: that of molecular psychiatry. Identification of different subtypes of neurotransmitter receptors and their changes in density and sensitivity in response to endogenous ligands and/or psychotropic drugs may account for the clinical expression of various behavioral phenomena, including some psychiatric disorders. Brain imaging, in particular positron-emission tomographic evaluations, are likely to change psychiatric nosology. New diagnostic elements derived from these scanners will allow to associate psychotic states to neuroreceptor changes. Molecular genetics has shown that bipolar affective disorder can be caused by a single gene. A strong linkage seems to exist between a gene locus on chromosome 11 and bipolar illness. An amyloid gene located on chromosome 21 has also been shown to be strongly related to familial Alzheimer's disease. While genetic heterogeneity limits the screening value of these findings, the powerful techniques of molecular biology have entered the field of psychiatry. Ethical issues regarding DNA immortality, gene cloning and gene therapy will strengthen this relationship.

  10. Molecular studies of achondroplasia

    Directory of Open Access Journals (Sweden)

    Nahar Risha

    2009-01-01

    Full Text Available Background: Achondroplasia (ACH is the most frequent form of short-limbed dwarfi sm, caused by mutations in the FGFR3 gene. It follows an autosomal dominant inheritance, though most cases are sporadic. The molecular techniques are the only available methods to confi rm the diagnosis of a skeletal dysplasia. Clinical and radiological features are only suggestive and not confi rmatory. The present study was conducted to fi nd out how often the clinical diagnosis of achondroplasia is verifi ed on molecular studies. Materials and Methods: From 1998 through 2007, we carried out molecular analysis for the two common mutations in the FGFR3 gene in 130 cases clinically suspected to have ACH. Results: A diagnostic mutation was identifi ed in 53 (40.8% cases. The common mutation (1138G>A was present in 50 (94.7% of the positive cases, while the rare 1138 G>C substitution was found in three (5.3%. Conclusion: This study shows that confi rmation of clinical diagnosis of ACH by molecular genetic testing is essential to distinguish it from other skeletal dysplasias, to plan therapeutic options, and to offer genetic counseling. Management (medical and surgical in patients confi rmed to have ACH, is briefl y discussed.

  11. Molecular diagnosis and immunotherapy.

    Science.gov (United States)

    Sastre, Joaquín; Sastre-Ibañez, Marina

    2016-12-01

    To describe recent insights into how molecular diagnosis can improve indication and selection of suitable allergens for specific immunotherapy and increase the safety of this therapy. As specific allergen immunotherapy targets specific allergens, identification of the disease-eliciting allergen is a prerequisite for accurate prescription of treatment. In areas of complex sensitization to aeroallergens or in cases of hymenoptera venom allergy, the use of molecular diagnosis has demonstrated that it may lead to a change in indication and selection of allergens for immunotherapy in a large proportion of patients when compared with diagnosis based on skin prick testing and/or specific IgE determination with commercial extracts. These changes in immunotherapy prescription aided by molecular diagnosis have been demonstrated to be cost-effective in some scenarios. Certain patterns of sensitization to grass or olive pollen and bee allergens may identify patients with higher risk of adverse reaction during immunotherapy. Molecular diagnosis, when used with other tools and patients' clinical records, can help clinicians better to select the most appropriate patients and allergens for specific immunotherapy and, in some cases, predict the risk of adverse reactions. The pattern of sensitization to allergens could potentially predict the efficacy of allergen immunotherapy provided that these immunotherapy products contain a sufficient amount of these allergens. Nevertheless, multiplex assay remains a third-level approach, not to be used as screening method in current practice.

  12. Isotopes in molecular biology

    International Nuclear Information System (INIS)

    Goldfarb, P.S.G.

    1988-01-01

    The use of radioisotopes in molecular biology, with particular reference to the structure and functions of DNA, RNA and the cellular synthesis of proteins, is discussed. The use of labelled DNA and RNA in diagnostic techniques is presented. (U.K.)

  13. Biophysics of molecular gastronomy.

    Science.gov (United States)

    Brenner, Michael P; Sörensen, Pia M

    2015-03-26

    Chefs and scientists exploring biophysical processes have given rise to molecular gastronomy. In this Commentary, we describe how a scientific understanding of recipes and techniques facilitates the development of new textures and expands the flavor palette. The new dishes that result engage our senses in unexpected ways. PAPERCLIP. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Molecular gastronomy in Spain

    DEFF Research Database (Denmark)

    García-Segovia, P.; Garrido, M. D.; Vercet, A.

    2014-01-01

    Beyond the overwhelming international success of Ferrán Adria, Spain has been one of the countries with a more active implication in molecular gastronomy as a scientific discipline but also in the use of ingredients, technologies, and equipment from the scientific and technological universe...... with scientists for facing the future of Spanish gastronomy....

  15. Molecular Mechanisms of Preeclampsia

    Directory of Open Access Journals (Sweden)

    N. Vitoratos

    2012-01-01

    Full Text Available Preeclampsia is one of the leading causes of maternal morbidity/mortality. The pathogenesis of preeclampsia is still under investigation. The aim of this paper is to present the molecular mechanisms implicating in the pathway leading to preeclampsia.

  16. Molecular MR Imaging Probes

    OpenAIRE

    MAHMOOD, UMAR; JOSEPHSON, LEE

    2005-01-01

    Magnetic resonance imaging (MRI) has been successfully applied to many of the applications of molecular imaging. This review discusses by example some of the advances in areas such as multimodality MR-optical agents, receptor imaging, apoptosis imaging, angiogenesis imaging, noninvasive cell tracking, and imaging of MR marker genes.

  17. Molecular dynamics for fermions

    International Nuclear Information System (INIS)

    Feldmeier, H.; Schnack, J.

    2000-02-01

    The time-dependent variational principle for many-body trial states is used to discuss the relation between the approaches of different molecular dynamics models to describe indistinguishable fermions. Early attempts to include effects of the Pauli principle by means of nonlocal potentials as well as more recent models which work with antisymmetrized many-body states are reviewed under these premises. (orig.)

  18. Nanopatterning by molecular polygons.

    Science.gov (United States)

    Jester, Stefan-S; Sigmund, Eva; Höger, Sigurd

    2011-07-27

    Molecular polygons with three to six sides and binary mixtures thereof form long-range ordered patterns at the TCB/HOPG interface. This includes also the 2D crystallization of pentagons. The results provide an insight into how the symmetry of molecules is translated into periodic structures.

  19. Molecular radio-oncology

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, Michael; Krause, Mechthild; Cordes, Nils (eds.) [Technische Univ. Dresden (Germany). Faculty of Medicine and University Hospital

    2016-07-01

    This book concisely reviews our current understanding of hypoxia, molecular targeting, DNA repair, cancer stem cells, and tumor pathophysiology, while also discussing novel strategies for putting these findings into practice in daily clinical routine. Radiotherapy is an important part of modern multimodal cancer treatment, and the past several years have witnessed not only substantial improvements in radiation techniques and the use of new beam qualities, but also major strides in our understanding of molecular tumor biology and tumor radiation response. Against this backdrop, the book highlights recent efforts to identify reasonable and clinically applicable biomarkers using broad-spectrum tissue microarrays and high-throughput systems biology approaches like genomics and epigenomics. In particular, it describes in detail how such molecular information is now being exploited for diagnostic imaging and imaging throughout treatment using the example of positron emission tomography. By discussing all these issues in the context of modern radiation oncology, the book provides a broad, up-to-date overview of the molecular aspects of radiation oncology that will hopefully foster its further optimization.

  20. Molecular radio-oncology

    International Nuclear Information System (INIS)

    Baumann, Michael; Krause, Mechthild; Cordes, Nils

    2016-01-01

    This book concisely reviews our current understanding of hypoxia, molecular targeting, DNA repair, cancer stem cells, and tumor pathophysiology, while also discussing novel strategies for putting these findings into practice in daily clinical routine. Radiotherapy is an important part of modern multimodal cancer treatment, and the past several years have witnessed not only substantial improvements in radiation techniques and the use of new beam qualities, but also major strides in our understanding of molecular tumor biology and tumor radiation response. Against this backdrop, the book highlights recent efforts to identify reasonable and clinically applicable biomarkers using broad-spectrum tissue microarrays and high-throughput systems biology approaches like genomics and epigenomics. In particular, it describes in detail how such molecular information is now being exploited for diagnostic imaging and imaging throughout treatment using the example of positron emission tomography. By discussing all these issues in the context of modern radiation oncology, the book provides a broad, up-to-date overview of the molecular aspects of radiation oncology that will hopefully foster its further optimization.

  1. Molecular Pathogenesis of Spondyloarthritis

    DEFF Research Database (Denmark)

    Carlsen, Thomas Gelsing

    This dissertation includes a presentation of knowledge on the molecular pathogenesis of spondyloarthritis achieved through a PhD programme at Aalborg University from 1.12.2011 - 1.12.2014. Work was carried out in the Laboratory of Medical Mass Spectrometry, headed by: Professor Svend Birkelund...

  2. Molecular-nuclear transitions

    International Nuclear Information System (INIS)

    Belyaev, V.B.; Miller, M.B.

    2007-01-01

    Full text: The spectra in some light nuclei have one interesting property. For example, in the closed vicinity of some resonance states of such nuclei as 5 He, 8 Be, 18 F, 18 Ne the thresholds exist for two- or three-body decay of those nuclei. Let us consider the lightest of the above nuclei, 5 He. The energy threshold for 5 He > d+t decay is ∼50 keV lower than the energy of 3/2 + state of 5 He nucleus. However, due to a rather large width of this state, ∼70 keV, the nuclear capture of deuterons by tritons in dtm-molecule is highly enhanced in comparison with the process of dd capture in the ddm molecule. The physical reason for the enhancement of the probability of the capture into the resonant state can be associated with a long tail of wave function of the resonant state and, accordingly, with the large value of the overlap integral determining in general the probability of the transition between two systems. Thus, one can expect the enhancement of the molecular-nuclear transitions, and this was indeed observed experimentally for the case of dtm molecule. Now, let us consider some other molecular-nuclear combinations: 18 Ne - H 2 O, 18 F - 17 OH, and 8 Be - 6 LiD molecule. With the high accuracy the energies of the above molecular systems coincide with the energies of the resonant states in the appropriate nuclei. Due to the uncertainty in the experimental nuclear data it is not known at present whether the energies of these thresholds are lower or higher of the corresponding energies of the nuclear resonances. Let us assume that the molecular energy is few keV over the energy of the nuclear resonance. Then, we will deal with a very interesting phenomenon: the molecular-nuclear complex constitutes a two level system, which in some sense is analogous to the two-level atomic system, as in a laser. The crucial difference between this one and the two-level atomic systems consists in a fact that in the molecular-nuclear case no special procedure of pumping up

  3. Molecular Simulation Study of Montmorillonite in Contact with Variably Wet Supercritical Carbon Dioxide

    KAUST Repository

    Kadoura, Ahmad Salim; Nair, Arun Kumar Narayanan; Sun, Shuyu

    2017-01-01

    We perform grand canonical Monte Carlo simulations to study the detailed molecular mechanism of intercalation behavior of CO2 in Na-, Ca-, and Mg- montmorillonite exposed to variably hydrated supercritical CO2 at 323.15 K and 90 bar, The simulations

  4. Molecular Dynamics Simulation Study of Carbon Dioxide, Methane, and Their Mixture in the Presence of Brine

    KAUST Repository

    Yang, Yafan; Nair, Arun Kumar Narayanan; Sun, Shuyu

    2017-01-01

    We perform molecular dynamics simulation study of CO2, methane, and their mixture in the presence of brine over a broad range of temperature (311–473 K), pressure (up to about 100 MPa), and NaCl concentration (up to about 14 wt %). The general

  5. Structure and properties of sodium aluminosilicate glasses from molecular dynamics simulations

    DEFF Research Database (Denmark)

    Xiang, Ye; Du, Jincheng; Smedskjær, Morten Mattrup

    2013-01-01

    the recent Corning® Gorilla® Glass. In this paper, the structures of sodium aluminosilicate glasses with a wide range of Al/Na ratios (from 1.5 to 0.6) have been studied using classical molecular dynamics simulations in a system containing around 3000 atoms, with the aim to understand the structural role...

  6. A comparative molecular dynamics study of diffusion of n-decane ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. Molecular dynamics simulations are reported on the structure and dynamics of n-decane and. 3-methylpentane in zeolite NaY. We have calculated several properties such as the center of mass-center of mass rdf, the end-end distance distribution, bond angle distribution and dihedral angle distribution. We.

  7. Elastic Coulomb breakup of 34Na

    Science.gov (United States)

    Singh, G.; Shubhchintak, Chatterjee, R.

    2016-08-01

    Background: 34Na is conjectured to play an important role in the production of seed nuclei in the alternate r -process paths involving light neutron rich nuclei very near the β -stability line, and as such, it is important to know its ground state properties and structure to calculate rates of the reactions it might be involved in, in the stellar plasma. Found in the region of `island of inversion', its ground state might not be in agreement with normal shell model predictions. Purpose: The aim of this paper is to study the elastic Coulomb breakup of 34Na on 208Pb to give us a core of 33Na with a neutron and in the process we try and investigate the one neutron separation energy and the ground state configuration of 34Na. Method: A fully quantum mechanical Coulomb breakup theory within the architecture of post-form finite range distorted wave Born approximation extended to include the effects of deformation is used to research the elastic Coulomb breakup of 34Na on 208Pb at 100 MeV/u. The triple differential cross section calculated for the breakup is integrated over the desired components to find the total cross-section, momentum, and angular distributions as well as the average momenta, along with the energy-angular distributions. Results: The total one neutron removal cross section is calculated to test the possible ground state configurations of 34Na. The average momentum results along with energy-angular calculations indicate 34Na to have a halo structure. The parallel momentum distributions with narrow full widths at half-maxima signify the same. Conclusion: We have attempted to analyze the possible ground state configurations of 34Na and in congruity with the patterns in the `island of inversion' conclude that even without deformation, 34Na should be a neutron halo with a predominant contribution to its ground state most probably coming from 33Na(3 /2+)⊗ 2 p3 /2ν configuration. We also surmise that it would certainly be useful and rewarding to test our

  8. Nuclear spin phonon relaxation by Raman process in Na{sub 3}H(SO{sub 4}){sub 2} single crystals with the electric-quadrupole-type interaction using {sup 1}H and {sup 23}Na NMR

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Ae Ran [Department of Science Education, Jeonju University, Jeonju 560-759, Chonbuk (Korea, Republic of)], E-mail: aeranlim@hanmail.net; Shin, Chang Woo [Solid State Analysis Team, Korea Basic Science Institute, Daegu 702-701 (Korea, Republic of)

    2008-11-30

    Successive phase transitions in a Na{sub 3}H(SO{sub 4}){sub 2} single crystal were found at 296, 513, and 533 K. To investigate the mechanism of the phase transition at 296 K, the {sup 1}H and {sup 23}Na spin-lattice relaxation time and the spin-spin relaxation time of Na{sub 3}H(SO{sub 4}){sub 2} were measured near the phase transition temperature using a FT NMR spectrometer. The spin-lattice relaxation time, T{sub 1}, for {sup 1}H in Na{sub 3}H(SO{sub 4}){sub 2} crystals exhibits a minimum below T{sub C1} (=296 K) indicating the presence of distinct molecular motion governed by the Bloembergen-Purcell-Pound (BPP) theory. Although the results for the {sup 1}H and {sup 23}Na relaxation times provide no evidence of the phase transition at T{sub C1}, the separation of the {sup 23}Na resonance lines changes abruptly at T{sub C1}. The phase transition at 296 K produces a change in the separation of the Na resonance line that is associated with a change in the atomic positions in the vicinity of the Na ions. Also, the nuclear spin-lattice relaxation process in Na{sub 3}H(SO{sub 4}){sub 2} crystals with the electric-quadrupole-type interaction proceed via Raman process. These results are compared with those obtained for other M{sub 3}H(SO{sub 4}){sub 2} (M=K, Rb, and Cs) crystals, which have similar hydrogen-bonded structures.

  9. Produção da proteína recombinante anexina V humana em cultivos de Escherichia coli em batelada alimentada

    OpenAIRE

    Marder, Laura Schirmbeck

    2013-01-01

    A Anexina V é uma proteína humana endógena dependente de Ca+2, com peso molecular de 35,8 kDa, amplamente distribuída intracelularmente em altas concentrações na placenta e em concentrações mais baixas nas células endoteliais, renais, miocárdicas, epiteliais, esqueléticas musculares, eritrócitos, plaquetas e monócitos. Apresenta como principal característica a capacidade de se ligar à fosfatidilserina, um fosfolipídeo presente na camada interna da bicamada lipídica, que durante a apoptose cel...

  10. Molecular imaging in oncology

    International Nuclear Information System (INIS)

    Weber, W.A.

    2007-01-01

    Molecular imaging is generally defined as noninvasive and quantitative imaging of targeted macromolecules and biological processes in living organisms. A characteristic of molecular imaging is the ability to perform repeated studies and assess changes in biological processes over time. Thus molecular imaging lends itself well for monitoring the effectiveness of tumor therapy. In animal models a variety of techniques can be used for molecular imaging. These include optical imaging (bioluminescence and fluorescence imaging), magnetic resonance imaging (MRI) and nuclear medicine techniques. In the clinical setting, however, nuclear medicine techniques predominate, because so far only radioactive tracers provide the necessary sensitivity to study expression and function of macromolecules non-invasively in patients. Nuclear medicine techniques allows to study a variety of biological processes in patients. These include the expression of various receptors (estrogen, androgen, somatostatin receptors and integrins). In addition, tracers are available to study tumor cell proliferation and hypoxia. The by far most commonly used molecular imaging technique in oncology is, however, positron emission tomography (PET) with the glucose analog [ 18 F]fluorodeoxyglucose (FDG-PET). FDG-PET permits non-invasive quantitative assessment of the accelerated exogenous glucose use of malignant tumors. Numerous studies have now shown that reduction of tumor FDG-uptake during therapy allows early prediction of tumor response and patient survival. Clinical studies are currently underway to determine whether FDG-PET can be used to individualize tumor therapy by signaling early in the course of therapy the need for therapeutic adjustments in patients with likely non-responding tumors. (orig.)

  11. HCO3(-)-coupled Na+ influx is a major determinant of Na+ turnover and Na+/K+ pump activity in rat hepatocytes

    International Nuclear Information System (INIS)

    Fitz, J.G.; Lidofsky, S.D.; Weisiger, R.A.; Xie, M.H.; Cochran, M.; Grotmol, T.; Scharschmidt, B.F.

    1991-01-01

    Recent studies in hepatocytes indicate that Na(+)-coupled HCO3- transport contributes importantly to regulation of intracellular pH and membrane HCO3- transport. However, the direction of net coupled Na+ and HCO3- movement and the effect of HCO3- on Na+ turnover and Na+/K+ pump activity are not known. In these studies, the effect of HCO3- on Na+ influx and turnover were measured in primary rat hepatocyte cultures with 22Na+, and [Na+]i was measured in single hepatocytes using the Na(+)-sensitive fluorochrome SBFI. Na+/K+ pump activity was measured in intact perfused rat liver and hepatocyte monolayers as Na(+)-dependent or ouabain-suppressible 86Rb uptake, and was measured in single hepatocytes as the effect of transient pump inhibition by removal of extracellular K+ on membrane potential difference (PD) and [Na+]i. In hepatocyte monolayers, HCO3- increased 22Na+ entry and turnover rates by 50-65%, without measurably altering 22Na+ pool size or cell volume, and HCO3- also increased Na+/K+ pump activity by 70%. In single cells, exposure to HCO3- produced an abrupt and sustained rise in [Na+]i from approximately 8 to 12 mM. Na+/K+ pump activity assessed in single cells by PD excursions during transient K+ removal increased congruent to 2.5-fold in the presence of HCO3-, and the rise in [Na+]i produced by inhibition of the Na+/K+ pump was similarly increased congruent to 2.5-fold in the presence of HCO3-. In intact perfused rat liver, HCO3- increased both Na+/K+ pump activity and O2 consumption. These findings indicate that, in hepatocytes, net coupled Na+ and HCO3- movement is inward and represents a major determinant of Na+ influx and Na+/K+ pump activity. About half of hepatic Na+/K+ pump activity appears dedicated to recycling Na+ entering in conjunction with HCO3- to maintain [Na+]i within the physiologic range

  12. Interaction of molecular oxygen with single wall nanotubes: Role of surfactant contamination

    International Nuclear Information System (INIS)

    Larciprete, R.; Goldoni, A.; Lizzit, S.

    2003-01-01

    The interaction of molecular oxygen with single wall nanotubes in the form of a commercial bucky paper was investigated by high resolution photoemission spectroscopy. Sodium contamination was found in the sample, which was completely removed only after prolonged heating at 1250 K. The C 1s core level spectrum measured on the sample annealed to 1020 K dramatically changed upon exposure to molecular oxygen. On the contrary, when exposing the Na-free SWNTs to several KL of O 2 , the sample remained oxygen free and no modification in the C 1s core level was observed. Therefore the observed sensitivity of the sample to O 2 was due to a Na mediated oxidation, determining a charge transfer from the C tubes to the Na-O complex

  13. Nonadiabatic ionic--covalent transitions. Exponential-linear model for the charge exchange and neutralization reactions Na+H arrow-right-left Na/sup +/+H/sup -/

    Energy Technology Data Exchange (ETDEWEB)

    Errea, L.F.; Mendez, L.; Mo, O.; Riera, A.

    1986-01-01

    A previous study of charge exchange processes taking place through ionic--covalent transitions is extended to the case of Na+H and Na/sup +/+H/sup -/ collisions. A five-state molecular expansion, with the inclusion of two-electron translation factors, is employed to calculate the charge exchange and neutralization cross sections. Transitions at the first two pseudocrossings between the energy curves, practically determine the cross sections in the energy range 0.16--5 keV amu/sup -1/. We also show that the widely used multichannel Landau--Zener theory is totally inadequate, to treat these transitions.

  14. Coulomb excitation of radioactive 20, 21Na

    Science.gov (United States)

    Schumaker, M. A.; Cline, D.; Hackman, G.; Pearson, C.; Svensson, C. E.; Wu, C. Y.; Andreyev, A.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D.; Becker, J. A.; Boston, A. J.; Boston, H. C.; Buchmann, L.; Churchman, R.; Cifarelli, F.; Cooper, R. J.; Cross, D. S.; Dashdorj, D.; Demand, G. A.; Dimmock, M. R.; Drake, T. E.; Finlay, P.; Gallant, A. T.; Garrett, P. E.; Green, K. L.; Grint, A. N.; Grinyer, G. F.; Harkness, L. J.; Hayes, A. B.; Kanungo, R.; Lisetskiy, A. F.; Leach, K. G.; Lee, G.; Maharaj, R.; Martin, J.-P.; Moisan, F.; Morton, A. C.; Mythili, S.; Nelson, L.; Newman, O.; Nolan, P. J.; Orce, J. N.; Padilla-Rodal, E.; Phillips, A. A.; Porter-Peden, M.; Ressler, J. J.; Roy, R.; Ruiz, C.; Sarazin, F.; Scraggs, D. P.; Waddington, J. C.; Wan, J. M.; Whitbeck, A.; Williams, S. J.; Wong, J.

    2009-12-01

    The low-energy structures of the radioactive nuclei 20, 21Na have been examined using Coulomb excitation at the TRIUMF-ISAC radioactive ion beam facility. Beams of ˜ 5×106 ions/s were accelerated to 1.7MeV/A and Coulomb excited in a 0.5mg/cm^2 natTi target. Two TIGRESS HPGe clover detectors perpendicular to the beam axis were used for γ -ray detection, while scattered nuclei were observed by the Si detector BAMBINO. For 21Na , Coulomb excitation from the 3/2+ ground state to the first excited 5/2+ state was observed, while for 20Na , Coulomb excitation was observed from the 2+ ground state to the first excited 3+ and 4+ states. For both beams, B ( λ L) values were determined using the 2+ rightarrow 0+ de-excitation in 48Ti as a reference. The resulting B( E2) ↓ value for 21Na is 137±9 e^2fm^4, while the resulting B( λ L) ↓ values for 20Na are 55±6 e^2fm^4 for the 3+ rightarrow 2+ , 35.7±5.7 e^2 fm^4 for the 4+ rightarrow 2+ , and 0.154±0.030 μ_ N^2 for the 4+ rightarrow 3+ transitions. This analysis significantly improves the measurement of the 21Na B( E2) value, and provides the first experimental determination of B( λ L) values for the proton dripline nucleus 20Na .-1

  15. The plant vacuolar Na+/H+ antiport.

    Science.gov (United States)

    Barkla, B J; Apse, M P; Manolson, M F; Blumwald, E

    1994-01-01

    Salt stress imposes severe limitations on plant growth, however, the extent of growth reduction depends upon the soil salinity level and the plant species. One of the mechanisms employed by salt tolerant plants is the effective vacuolar compartmentalization of sodium. The sequestration of sodium into the vacuole occurs by the operation of a Na+/H+ antiport located at the tonoplast. Evidence for a plant vacuolar Na+/H+ antiport has been demonstrated in tissues, intact vacuoles and isolated tonoplast vesicles. In sugar beet cell suspensions, the activity of the vacuolar Na+/H+ antiport increased with increasing NaCl concentrations in the growth medium. This increased activity was correlated with the increased synthesis of a 170 kDa tonoplast polypeptide. In vivo labelling of tonoplast proteins showed the enhanced synthesis of the 170 kDa polypeptide not only upon exposure of the cells to salt, but also when the cells were grown in the presence of amiloride. Exposure of the cells to amiloride also resulted in increased vacuolar Na+/H+ antiport activity. Polyclonal antibodies raised against the 170 kDa polypeptide almost completely inhibited the antiport activity, suggesting the association of this protein with the plant vacuolar Na+/H+ antiport. Antibodies against the Na+/H+ antiport-associated polypeptide were used to screen a Beta lambda ZAP expression library. A partial clone of 1.65 kb was sequenced and found to encode a polypeptide with a putative transmembrane domain and a large hydrophilic C terminus. This clone showed no homology to any previously cloned gene at either the nucleic acid or the amino acid level.

  16. DNA fingerprinting of sugarcane for detecting molecular evidence of somaclonal variation

    International Nuclear Information System (INIS)

    Ramos Leal, M.; Canales, E.; Michel, R.; Coto, O.; Cornide, M.T.

    1998-01-01

    Molecular characterisation of eight sugarcane mutants which tolerate 1% NaCl, was performed by means of restriction fragment length polymorphism (RFLP) analysis at the genomic level, using a group of molecular probes for ribosomal DNAs and two others, Δ-pyrroline-5-carboxylate reductase (ΔP5CR) and ATPase, probably related to salinity stress tolerance. Results showed the molecular evidence of genetic changes in comparison to the susceptible donor variety and the possible presence of more that one mechanism to tolerate salt stress. (author)

  17. TweetNaCl : a crypto library in 100 tweets

    NARCIS (Netherlands)

    Bernstein, D.J.; van Gastel, B.; Janssen, W.; Lange, T.; Schwabe, P.; Smetsers, S.; Aranha, D.F.; Menezes, A.

    2015-01-01

    This paper introduces TweetNaCl, a compact reimplementation of the NaCl library, including all 25 of the NaCl functions used by applications. TweetNaCl is published on Twitter and fits into just 100 tweets; the tweets are available from anywhere, any time, in an unsuspicious way. Distribution via

  18. Kupokelewa Zaidi Kwa Simu Ya Mkononi Kuliko Kompyuta Na ...

    African Journals Online (AJOL)

    Mtandao wa tovuti ni nyenzo ya msingi katika maendeleo ya uwanja wa mawasiliano unaounganisha watu na jamii mbalimbali katika ulimwengu wa leo unaotandawaa. Katika “ulimwengu wa kwanza na wa pili”, yaani mabara ya Amerika, Uropa na Asia, maendeleo na mapinduzi makubwa katika uwanja wa teknolojia ya ...

  19. Mabadiliko Ya Kifonolojia Na Kimofolojia Wakati Wa Utohozi Wa ...

    African Journals Online (AJOL)

    Mwingiliano wa lugha ya Kiswahili na Kiarabu una historia ndefu kidogo. Inasemekana Waarabu walianza muwasala na 'Waswahili' tangu karne ya kwanza (BK) (Polome 1967:9). Kutokana na muwasala huo wa muda mrefu, lugha hizi mbili (Kiarabu na Kiswahili) zimeathiriana sana. Lakini kuna maoni kwamba Kiarabu ...

  20. How NaCl raises blood pressure: a new paradigm for the pathogenesis of salt-dependent hypertension

    Science.gov (United States)

    Leenen, Frans H. H.; Chen, Ling; Golovina, Vera A.; Hamlyn, John M.; Pallone, Thomas L.; Van Huysse, James W.; Zhang, Jin; Wier, W. Gil

    2012-01-01

    Excess dietary salt is a major cause of hypertension. Nevertheless, the specific mechanisms by which salt increases arterial constriction and peripheral vascular resistance, and thereby raises blood pressure (BP), are poorly understood. Here we summarize recent evidence that defines specific molecular links between Na+ and the elevated vascular resistance that directly produces high BP. In this new paradigm, high dietary salt raises cerebrospinal fluid [Na+]. This leads, via the Na+-sensing circumventricular organs of the brain, to increased sympathetic nerve activity (SNA), a major trigger of vasoconstriction. Plasma levels of endogenous ouabain (EO), the Na+ pump ligand, also become elevated. Remarkably, high cerebrospinal fluid [Na+]-evoked, locally secreted (hypothalamic) EO participates in a pathway that mediates the sustained increase in SNA. This hypothalamic signaling chain includes aldosterone, epithelial Na+ channels, EO, ouabain-sensitive α2 Na+ pumps, and angiotensin II (ANG II). The EO increases (e.g.) hypothalamic ANG-II type-1 receptor and NADPH oxidase and decreases neuronal nitric oxide synthase protein expression. The aldosterone-epithelial Na+ channel-EO-α2 Na+ pump-ANG-II pathway modulates the activity of brain cardiovascular control centers that regulate the BP set point and induce sustained changes in SNA. In the periphery, the EO secreted by the adrenal cortex directly enhances vasoconstriction via an EO-α2 Na+ pump-Na+/Ca2+ exchanger-Ca2+ signaling pathway. Circulating EO also activates an EO-α2 Na+ pump-Src kinase signaling cascade. This increases the expression of the Na+/Ca2+ exchanger-transient receptor potential cation channel Ca2+ signaling pathway in arterial smooth muscle but decreases the expression of endothelial vasodilator mechanisms. Additionally, EO is a growth factor and may directly participate in the arterial structural remodeling and lumen narrowing that is frequently observed in established hypertension. These several

  1. Conformation analysis of trehalose. Molecular dynamics simulation and molecular mechanics

    International Nuclear Information System (INIS)

    Donnamaira, M.C.; Howard, E.I.; Grigera, J.R.

    1992-09-01

    Conformational analysis of the disaccharide trehalose is done by molecular dynamics and molecular mechanics. In spite of the different force fields used in each case, comparison between the molecular dynamics trajectories of the torsional angles of glycosidic linkage and energy conformational map shows a good agreement between both methods. By molecular dynamics it is observed a moderate mobility of the glycosidic linkage. The demands of computer time is comparable in both cases. (author). 6 refs, 4 figs

  2. O Passeio Público do Rio de Janeiro na Literatura, na Pintura e na Fotografia do Século XIX

    Directory of Open Access Journals (Sweden)

    Solange de Aragão

    2012-06-01

    Full Text Available Este artigo tem como objetivo geral e mais amplo chamar a atenção dos pesquisadores para a importância da literatura, da pintura e da fotografia como fontes documentais para a construção da História do Paisagismo no Brasil por meio de um estudo de caso muito particular: o Passeio Público do Rio de Janeiro no século XIX. São objetivos específicos apresentar e analisar o modo como esse espaço livre público aparece na literatura, na pintura e na fotografia desse período, considerando suas transformações paisagísticas.

  3. Genética Molecular das Epidermólises Bolhosas Molecular Genetics of Epidermolysis Bullosa

    Directory of Open Access Journals (Sweden)

    Hiram Larangeira de Almeida Jr

    2002-10-01

    Full Text Available O estudo das alterações moleculares das epidermólises bolhosas tem contribuído para que se compreenda melhor essas enfermidades. Na epidermólise bolhosa simples a maioria dos casos está associada com alteração nas citoqueratinas basais 5 (gen KRT5 e 14 (gen KRT14, o que modifica o citoesqueleto na camada basal da epiderme, levando à degeneração dessa camada, formando bolha intra-epidérmica. Mutações na plectina (gen PLEC1, componente da placa interna do hemidesmossoma, levam também à clivagem intra-epidérmica. Na epidermólise bolhosa juncional vários gens estão envolvidos, em decorrência da complexidade da zona da membrana basal, todos levando ao descolamento dos queratinócitos basais na lâmina lúcida, pela disfunção da aderência entre esses e a lâmina densa. Alterações na laminina 5 (gens LAMA3, LAMB3 e LAMC2, integrina alfa6beta4 (gens ITGA6 e ITGB4 e colágeno XVII (gen COL17A1 foram descritas. Por fim, na epidermólise bolhosa distrófica apenas um gen está mutado, alterando o colágeno VII (gen COL7A1, principal componente das fibrilas ancorantes, produzindo clivagem abaixo da lâmina densa, variando fenotipicamente de acordo com a conseqüência da mutação. Outra aplicação importante dessas informações refere-se ao diagnóstico pré-natal, com a perspectiva no futuro da terapia gênica.New data regarding the molecular aspects of the heterogeneous group of epidermolysis bullosa has brought some important information about its pathogenesis. In epidermolysis bullosa simplex the majority of mutations are localized in the genes of the basal cytokeratin 5 (gene KRT5 and 14 (gene KRT14, cytolysis at this layer with intraepidermal blister is seen under light microscopy. Mutations of plectin (gene PLEC1, a protein found in the inner hemidesmosomal plaque, leads also to intraepidermal blisters. In junctional epidermolysis bullosa many proteins from the basal membrane zone are involved, such as laminin 5 (genes

  4. Cardiac glycoside activities link Na(+)/K(+) ATPase ion-transport to breast cancer cell migration via correlative SAR.

    Science.gov (United States)

    Magpusao, Anniefer N; Omolloh, George; Johnson, Joshua; Gascón, José; Peczuh, Mark W; Fenteany, Gabriel

    2015-02-20

    The cardiac glycosides ouabain and digitoxin, established Na(+)/K(+) ATPase inhibitors, were found to inhibit MDA-MB-231 breast cancer cell migration through an unbiased chemical genetics screen for cell motility. The Na(+)/K(+) ATPase acts both as an ion-transporter and as a receptor for cardiac glycosides. To delineate which function is related to breast cancer cell migration, structure-activity relationship (SAR) profiles of cardiac glycosides were established at the cellular (cell migration inhibition), molecular (Na(+)/K(+) ATPase inhibition), and atomic (computational docking) levels. The SAR of cardiac glycosides and their analogs revealed a similar profile, a decrease in potency when the parent cardiac glycoside structure was modified, for each activity investigated. Since assays were done at the cellular, molecular, and atomic levels, correlation of SAR profiles across these multiple assays established links between cellular activity and specific protein-small molecule interactions. The observed antimigratory effects in breast cancer cells are directly related to the inhibition of Na(+)/K(+) transport. Specifically, the orientation of cardiac glycosides at the putative cation permeation path formed by transmembrane helices αM1-M6 correlates with the Na(+) pump activity and cell migration. Other Na(+)/K(+) ATPase inhibitors that are structurally distinct from cardiac glycosides also exhibit antimigratory activity, corroborating the conclusion that the antiport function of Na(+)/K(+) ATPase and not the receptor function is important for supporting the motility of MDA-MB-231 breast cancer cells. Correlative SAR can establish new relationships between specific biochemical functions and higher-level cellular processes, particularly for proteins with multiple functions and small molecules with unknown or various modes of action.

  5. Steroid-like compounds in Chinese medicines promote blood circulation via inhibition of Na+/K+ -ATPase.

    Science.gov (United States)

    Chen, Ronald J Y; Chung, Tse-yu; Li, Feng-yin; Yang, Wei-hung; Jinn, Tzyy-rong; Tzen, Jason T C

    2010-06-01

    To examine if steroid-like compounds found in many Chinese medicinal products conventionally used for the promotion of blood circulation may act as active components via the same molecular mechanism triggered by cardiac glycosides, such as ouabain. The inhibitory potency of ouabain and the identified steroid-like compounds on Na(+)/K(+)-ATPase activity was examined and compared. Molecular modeling was exhibited for the docking of these compounds to Na(+)/K(+)-ATPase. All the examined steroid-like compounds displayed more or less inhibition on Na(+)/K(+)-ATPase, with bufalin (structurally almost equivalent to ouabain) exhibiting significantly higher inhibitory potency than the others. In the pentacyclic triterpenoids examined, ursolic acid and oleanolic acid were moderate inhibitors of Na(+)/K(+)-ATPase, and their inhibitory potency was comparable to that of ginsenoside Rh2. The relatively high inhibitory potency of ursolic acid or oleanolic acid was due to the formation of a hydrogen bond between its carboxyl group and the Ile322 residue in the deep cavity close to two K(+) binding sites of Na(+)/K(+)-ATPase. Moreover, the drastic difference observed in the inhibitory potency of ouabain, bufalin, ginsenoside Rh2, and pentacyclic triterpenoids is ascribed mainly to the number of hydrogen bonds and partially to the strength of hydrophobic interaction between the compounds and residues around the deep cavity of Na(+)/K(+)-ATPase. Steroid-like compounds seem to contribute to therapeutic effects of many cardioactive Chinese medicinal products. Chinese herbs, such as Prunella vulgaris L, rich in ursolic acid, oleanolic acid and their glycoside derivatives may be adequate sources for cardiac therapy via effective inhibition on Na(+)/K(+)-ATPase.

  6. VPLIV CENE NA ZADOVOLJSTVO IN ZVESTOBO UPORABNIKOV TELEKOMUNIKACIJSKIH STORITEV

    OpenAIRE

    Majcen, Mateja

    2016-01-01

    Cena izdelka ali storitve, ki jo plača uporabnik, ima pomemben vpliv na zadovoljstvo ali nezadovoljstvo uporabnika z uporabo tega izdelka ali storitve in posledično na zadovoljstvo do podjetja. Glede na to, da se različni avtorji strinjajo in to tudi dokazujejo z raziskavami, zadovoljstvo nedvoumno vpliva na zvestobo uporabnika, zvestoba pa na dolgoročno uspešnost podjetja, smo v delu ugotavljali, kako sama cena storitve vpliva na zadovoljstvo in kako posredno preko zadovoljstva vpliva na zve...

  7. Muziki wa Hip Hop na Haki Za Kijamii: Dhima, Changamoto na ...

    African Journals Online (AJOL)

    Ni dhahiri kuwa haki za kijamii zinaweza kuwasilishwa kwa jamii pana kupitia sanaa ya hip hop. Makala haya basi, yanabainisha dhima na mchango wa muziki wa hip hop katika masuala ya haki za kijamii, yanafafanua changamoto za muziki huu katika kuwasilisha haki za kijamii na kutoa mapendekezo kwa makundi ...

  8. NaI(Tl) electron energy resolution

    CERN Document Server

    Mengesha, W

    2002-01-01

    NaI(Tl) electron energy resolution eta sub e was measured using the Modified Compton Coincidence Technique (MCCT). The MCCT allowed detection of nearly monoenergetic internal electrons resulting from the scattering of incident 662 keV gamma rays within a primary NaI(Tl) detector. Scattered gamma rays were detected using a secondary HPGe detector in a coincidence mode. Measurements were carried out for electron energies ranging from 16 to 438 keV, by varying the scattering angle. Measured HPGe coincidence spectra were deconvolved to determine the scattered energy spectra from the NaI(Tl) detector. Subsequently, the NaI(Tl) electron energy spectra were determined by subtracting the energy of scattered spectra from the incident source energy (662 keV). Using chi-squared minimization, iterative deconvolution of the internal electron energy spectra from the measured NaI(Tl) spectra was then used to determine eta sub e at the electron energy of interest. eta sub e values determined using this technique represent va...

  9. Theoretical and experimental approach on the molecular interactions of the DL-Alanine with an electrolytic environment

    Science.gov (United States)

    Cantero-López, Plinio; Yañez-Osses, Osvaldo; Páez-Meza, Manuel Silvestre; López, Johana E.; Páez-Hernández, Dayán; Arratia-Pérez, Ramiro

    2017-11-01

    The molecular interactions that promote the stability of proteins and amino acids in saline solutions is a central topic of molecular biophysics. However, a well-supported molecular picture of the phenomena has not been established yet. In this paper, we studied as model system the mix between DL-Alanine in aqueous solutions of STP (Na2S2O3·5H2O) at different temperatures, from volumetric and viscometric properties. The thermophysical properties obtained indicate the presence of a strong preferential solvation, structure-making action and a possible salt in effect. Quantum chemical calculations and molecular dynamic (MD) simulations provide a new insight to support these arguments.

  10. Regulation of renal function and structure by the signaling Na/K-ATPase.

    Science.gov (United States)

    Xie, Jeffrey X; Li, Xin; Xie, Zijian

    2013-12-01

    The Na/K-ATPase as an essential ion pump was discovered more than 50 years ago (Skou (1989) Biochim. Biophys. Acta 1000, 439-446; Feraille and Doucet (2001) Physiol. Rev. 81, 345-418). The signaling function of Na/K-ATPase has been gradually appreciated over the last 20 years, first from the studies of regulatory effects of ouabain on cardiac cell growth. Several reviews on this topic have been written during the last few years (Schoner and Scheiner-Bobis (2007) Am. J. Physiol. Cell. Physiol. 293, C509-C536; Xie and Cai (2003) Mol. Interv. 3, 157 - 168; Bagrov et al. (2009) Pharmacol. Rev. 61, 9-38; Tian and Xie (2008) Physiology 23, 205-211; Fontana et al. (2013) FEBS J. 280, 5450-5455; Blanco and Wallace (2013) Am. J. Physiol. Renal Physiol. 305, F797-F812). This article will focus on the molecular mechanism of Na/K-ATPase-mediated signal transduction and its potential regulatory role in renal physiology and diseases. © 2013 International Union of Biochemistry and Molecular Biology.

  11. Topology in Molecular Biology

    CERN Document Server

    Monastyrsky, Michail Ilych

    2007-01-01

    The book presents a class of new results in molecular biology for which topological methods and ideas are important. These include: the large-scale conformation properties of DNA; computational methods (Monte Carlo) allowing the simulation of large-scale properties of DNA; the tangle model of DNA recombination and other applications of Knot theory; dynamics of supercoiled DNA and biocatalitic properties of DNA; the structure of proteins; and other very recent problems in molecular biology. The text also provides a short course of modern topology intended for the broad audience of biologists and physicists. The authors are renowned specialists in their fields and some of the new results presented here are documented for the first time in monographic form.

  12. Molecular and Cellular Signaling

    CERN Document Server

    Beckerman, Martin

    2005-01-01

    A small number of signaling pathways, no more than a dozen or so, form a control layer that is responsible for all signaling in and between cells of the human body. The signaling proteins belonging to the control layer determine what kinds of cells are made during development and how they function during adult life. Malfunctions in the proteins belonging to the control layer are responsible for a host of human diseases ranging from neurological disorders to cancers. Most drugs target components in the control layer, and difficulties in drug design are intimately related to the architecture of the control layer. Molecular and Cellular Signaling provides an introduction to molecular and cellular signaling in biological systems with an emphasis on the underlying physical principles. The text is aimed at upper-level undergraduates, graduate students and individuals in medicine and pharmacology interested in broadening their understanding of how cells regulate and coordinate their core activities and how diseases ...

  13. Activating the molecular spinterface

    Science.gov (United States)

    Cinchetti, Mirko; Dediu, V. Alek; Hueso, Luis E.

    2017-05-01

    The miniaturization trend in the semiconductor industry has led to the understanding that interfacial properties are crucial for device behaviour. Spintronics has not been alien to this trend, and phenomena such as preferential spin tunnelling, the spin-to-charge conversion due to the Rashba-Edelstein effect and the spin-momentum locking at the surface of topological insulators have arisen mainly from emergent interfacial properties, rather than the bulk of the constituent materials. In this Perspective we explore inorganic/molecular interfaces by looking closely at both sides of the interface. We describe recent developments and discuss the interface as an ideal platform for creating new spin effects. Finally, we outline possible technologies that can be generated thanks to the unique active tunability of molecular spinterfaces.

  14. Measuring Dark Molecular Gas

    Science.gov (United States)

    Li, Di; Heiles, Carl E.

    2017-01-01

    It is now well known that a substantial fraction of Galactic molecular gas cannot be traced by CO emission. The thus dubbed CO dark molecular gas (DMG) occupy a large volume of ISM with intermediate extinction, where CO is either not self-shielded and/or subthermally excited. We explore the utilities of simple hydrides, such OH, CH, etc., in tracing DMG. We mapped and modeled the transition zone cross a cloud boundary and derived emperical OH abundance and DMG distribution formulae. We also obtained absorption measurements of various species using Arecibo, VLA, ATCA, and ALMA. The absorption technique has the potential to provide systematic quantification of DMG in the next few years.

  15. Anion-coupled Na efflux mediated by the human red blood cell Na/K pump

    International Nuclear Information System (INIS)

    Dissing, S.; Hoffman, J.F.

    1990-01-01

    The red cell Na/K pump is known to continue to extrude Na when both Na and K are removed from the external medium. Because this ouabain-sensitive flux occurs in the absence of an exchangeable cation, it is referred to as uncoupled Na efflux. This flux is also known to be inhibited by 5 mM Nao but to a lesser extent than that inhibitable by ouabain. Uncoupled Na efflux via the Na/K pump therefore can be divided into a Nao-sensitive and Nao-insensitive component. We used DIDS-treated, SO4-equilibrated human red blood cells suspended in HEPES-buffered (pHo 7.4) MgSO4 or (Tris)2SO4, in which we measured 22Na efflux, 35SO4 efflux, and changes in the membrane potential with the fluorescent dye, diS-C3 (5). A principal finding is that uncoupled Na efflux occurs electroneurally, in contrast to the pump's normal electrogenic operation when exchanging Nai for Ko. This electroneutral uncoupled efflux of Na was found to be balanced by an efflux of cellular anions. (We were unable to detect any ouabain-sensitive uptake of protons, measured in an unbuffered medium at pH 7.4 with a Radiometer pH-STAT.) The Nao-sensitive efflux of Nai was found to be 1.95 +/- 0.10 times the Nao-sensitive efflux of (SO4)i, indicating that the stoichiometry of this cotransport is two Na+ per SO4=, accounting for 60-80% of the electroneutral Na efflux. The remainder portion, that is, the ouabain-sensitive Nao-insensitive component, has been identified as PO4-coupled Na transport and is the subject of a separate paper. That uncoupled Na efflux occurs as a cotransport with anions is supported by the result, obtained with resealed ghosts, that when internal and external SO4 was substituted by the impermeant anion, tartrate i,o, the efflux of Na was inhibited 60-80%. This inhibition could be relieved by the inclusion, before DIDS treatment, of 5 mM Cli,o

  16. Na/K pump inactivation, subsarcolemmal Na measurements, and cytoplasmic ion turnover kinetics contradict restricted Na spaces in murine cardiac myocytes.

    Science.gov (United States)

    Lu, Fang-Min; Hilgemann, Donald W

    2017-07-03

    Decades ago, it was proposed that Na transport in cardiac myocytes is modulated by large changes in cytoplasmic Na concentration within restricted subsarcolemmal spaces. Here, we probe this hypothesis for Na/K pumps by generating constitutive transsarcolemmal Na flux with the Na channel opener veratridine in whole-cell patch-clamp recordings. Using 25 mM Na in the patch pipette, pump currents decay strongly during continuous activation by extracellular K (τ, ∼2 s). In contradiction to depletion hypotheses, the decay becomes stronger when pump currents are decreased by hyperpolarization. Na channel currents are nearly unchanged by pump activity in these conditions, and conversely, continuous Na currents up to 0.5 nA in magnitude have negligible effects on pump currents. These outcomes are even more pronounced using 50 mM Li as a cytoplasmic Na congener. Thus, the Na/K pump current decay reflects mostly an inactivation mechanism that immobilizes Na/K pump charge movements, not cytoplasmic Na depletion. When channel currents are increased beyond 1 nA, models with unrestricted subsarcolemmal diffusion accurately predict current decay (τ ∼15 s) and reversal potential shifts observed for Na, Li, and K currents through Na channels opened by veratridine, as well as for Na, K, Cs, Li, and Cl currents recorded in nystatin-permeabilized myocytes. Ion concentrations in the pipette tip (i.e., access conductance) track without appreciable delay the current changes caused by sarcolemmal ion flux. Importantly, cytoplasmic mixing volumes, calculated from current decay kinetics, increase and decrease as expected with osmolarity changes (τ >30 s). Na/K pump current run-down over 20 min reflects a failure of pumps to recover from inactivation. Simulations reveal that pump inactivation coupled with Na-activated recovery enhances the rapidity and effectivity of Na homeostasis in cardiac myocytes. In conclusion, an autoregulatory mechanism enhances cardiac Na/K pump activity when

  17. Carbon monoxide induces cardiac arrhythmia via induction of the late Na+ current.

    Science.gov (United States)

    Dallas, Mark L; Yang, Zhaokang; Boyle, John P; Boycott, Hannah E; Scragg, Jason L; Milligan, Carol J; Elies, Jacobo; Duke, Adrian; Thireau, Jérôme; Reboul, Cyril; Richard, Sylvain; Bernus, Olivier; Steele, Derek S; Peers, Chris

    2012-10-01

    Clinical reports describe life-threatening cardiac arrhythmias after environmental exposure to carbon monoxide (CO) or accidental CO poisoning. Numerous case studies describe disruption of repolarization and prolongation of the QT interval, yet the mechanisms underlying CO-induced arrhythmias are unknown. To understand the cellular basis of CO-induced arrhythmias and to identify an effective therapeutic approach. Patch-clamp electrophysiology and confocal Ca(2+) and nitric oxide (NO) imaging in isolated ventricular myocytes was performed together with protein S-nitrosylation to investigate the effects of CO at the cellular and molecular levels, whereas telemetry was used to investigate effects of CO on electrocardiogram recordings in vivo. CO increased the sustained (late) component of the inward Na(+) current, resulting in prolongation of the action potential and the associated intracellular Ca(2+) transient. In more than 50% of myocytes these changes progressed to early after-depolarization-like arrhythmias. CO elevated NO levels in myocytes and caused S-nitrosylation of the Na(+) channel, Na(v)1.5. All proarrhythmic effects of CO were abolished by the NO synthase inhibitor l-NAME, and reversed by ranolazine, an inhibitor of the late Na(+) current. Ranolazine also corrected QT variability and arrhythmias induced by CO in vivo, as monitored by telemetry. Our data indicate that the proarrhythmic effects of CO arise from activation of NO synthase, leading to NO-mediated nitrosylation of Na(V)1.5 and to induction of the late Na(+) current. We also show that the antianginal drug ranolazine can abolish CO-induced early after-depolarizations, highlighting a novel approach to the treatment of CO-induced arrhythmias.

  18. Production of gaseous radiotracers CH3I and I2 through Na123I salt

    International Nuclear Information System (INIS)

    Candeiro, R.E.M.; Pereira, W.P.

    2011-01-01

    The objective of the present work was to develop, separately, methodology for production of two gaseous tracers through the sodium iodide NaI marked with 123 I. Found in the nature in form different, the iodine has been used in diverse works in the area of the industry and health. These two forms of the gaseous iodine, the methyl iodide, CH 3 I, and molecular iodine, I 2 , are very unstable and volatile in the ambient temperature and presents different problems in clean-up and monitoring systems. The syntheses were processed with sodium iodide (NaI) 1M aqueous solution marked with 1 23I . The production of gas I 2 was realized with in chlorine acid (HCl) and sodium iodate salt (NaIO 3 ) and the CH 3 I was used, the salt of NaI and the reagent (CH 3 ) 2 SO 4 . The production of gases was initially realized through in unit in glass with an inert material and the purpose was to study the kinetic of reaction and to determine the efficiency of production. The two synthesis occurs in the reaction bottle and after of produced, the gas is stored in the collect bottle that contains a starch solution for fixed the I 2 , and in syntheses of CH 3 I contains a silver nitrate solution for your fixation. To determine the efficiency of production of gases, analytic tests were realized, where the consumption of iodide ions of the bottle of reaction are measured. The optimization of production of the each gaseous tracer was studied varying parameter as: concentration of iodide, concentration of acid and temperature. After, the syntheses of the radiotracers were realized in the compact unit, having been used as main reagent the salt radiated of sodium iodide, Na 123 I. The transportation of elementary iodine and methyl iodine was studied by a scintillation detector NaI (2 x 2)' positioned in the reaction bottle. (author)

  19. Molecular Mechanisms of Preeclampsia

    OpenAIRE

    N. Vitoratos; D. Hassiakos; C. Iavazzo

    2012-01-01

    Preeclampsia is a pregnancy-specific disease characterized by new onset hypertension and proteinuria after 20 wk of gestation. It is a leading cause of maternal and fetal morbidity and mortality worldwide. Exciting discoveries in the last decade have contributed to a better understanding of the molecular basis of this disease. Epidemiological, experimental, and therapeutic studies from several laboratories have provided compelling evidence that an antiangiogenic state owing to alterations in ...

  20. Molecular diagnostics of periodontitis

    OpenAIRE

    Izabela Korona-Głowniak; Radosław Siwiec; Marcin Berger; Anna Malm; Jolanta Szymańska

    2017-01-01

    The microorganisms that form dental plaque are the main cause of periodontitis. Their identification and the understanding of the complex relationships and interactions that involve these microorganisms, environmental factors and the host’s health status enable improvement in diagnostics and targeted therapy in patients with periodontitis. To this end, molecular diagnostics techniques (both techniques based on the polymerase chain reaction and those involving nucleic acid analysis via hybridi...

  1. Molecular diagnostics in endodontics

    OpenAIRE

    Rechenberg, Dan-Krister; Zehnder, Matthias

    2014-01-01

    Recent systematic reviews have substantiated the fact that current testing methods to assess the inflammatory state of the pulp and the periapical tissues are of limited value. Consequently, it may be time to search for alternative routes in endodontic diagnostics. Molecular assessment methods could be the future. However, in the field of endodontics, the research in that direction is only about to evolve. Because pulpal and periradicular diseases are related to opportunistic infections, diag...

  2. Molecular Diagnostics of ?-Thalassemia

    OpenAIRE

    Atanasovska, B; Bozhinovski, G; Chakalova, L; Kocheva, S; Karanfilski, O; Plaseska-Karanfiska, D

    2012-01-01

    A high-quality hemoglobinopathy diagnosis is based on the results of a number of tests including assays for molecular identification of causative mutations. We describe the current diagnostic strategy for the identification of ?-thalassemias and hemoglobin (Hb) variants at the International Reference Laboratory for Haemoglobinopathies, Research Centre for Genetic Engineering and Biotechnology (RCGEB) ?Georgi D. Efremov,? Skopje, Republic of Macedonia. Our overall approach and most of the meth...

  3. Molecular biomethods handbook

    National Research Council Canada - National Science Library

    Walker, John M; Rapley, Ralph

    2008-01-01

    ... the reader to a selection of analytical and preparative techniques that we considered to be frequently used by research workers in the field of molecular biology. Clearly, within the constraints of a single volume we had to be selective in the techniques we described. Since the first edition was published, science has continued to move on apace. For example, the use of microarray technology is now commonplace, nanotechnology has entered the scientific literature, microfluidic technology has be...

  4. Molecular Vaccines for Malaria

    Science.gov (United States)

    2010-01-01

    Removing inhibitory plasm ids from the cock- with the radiation-attenuated sporozoite (RAS) vaccine36•37 (see tail restored the immunogenicity of the...relative increased in vitro growth inhibitory activity against homologous to the P. folciparum antigen expressing plasm ids alone, and none parasites...25nm and have a molecular weight of 14.8 kDa. (C) Transmission electron microscopy image of P4c-Mal nanoparticles at 242 OOOx. The sample was

  5. Designing the molecular future

    OpenAIRE

    Schneider Gisbert

    2011-01-01

    Approximately 25 years ago the first computer applications were conceived for the purpose of automated 'de novo' drug design prominent pioneering tools being ALADDIN CAVEAT GENOA and DYLOMMS. Many of these early concepts were enabled by innovative techniques for ligand receptor interaction modeling like GRID MCSS DOCK and CoMFA which still provide the theoretical framework for several more recently developed molecular design algorithms. After a first wave of software tools and groundbreaking ...

  6. Atomic and molecular theory

    International Nuclear Information System (INIS)

    Inokuti, Mitio.

    1990-01-01

    The multifaceted role of theoretical physics in understanding the earliest stages of radiation action is discussed. Scientific topics chosen for the present discourse include photoabsorption, electron collisions, and ionic collisions, and electron transport theory, Connections of atomic and molecular physics with condensed-matter physics are also discussed. The present article includes some historical perspective and an outlook for the future. 114 refs., 3 figs

  7. Molecular ecological network analyses.

    Science.gov (United States)

    Deng, Ye; Jiang, Yi-Huei; Yang, Yunfeng; He, Zhili; Luo, Feng; Zhou, Jizhong

    2012-05-30

    Understanding the interaction among different species within a community and their responses to environmental changes is a central goal in ecology. However, defining the network structure in a microbial community is very challenging due to their extremely high diversity and as-yet uncultivated status. Although recent advance of metagenomic technologies, such as high throughout sequencing and functional gene arrays, provide revolutionary tools for analyzing microbial community structure, it is still difficult to examine network interactions in a microbial community based on high-throughput metagenomics data. Here, we describe a novel mathematical and bioinformatics framework to construct ecological association networks named molecular ecological networks (MENs) through Random Matrix Theory (RMT)-based methods. Compared to other network construction methods, this approach is remarkable in that the network is automatically defined and robust to noise, thus providing excellent solutions to several common issues associated with high-throughput metagenomics data. We applied it to determine the network structure of microbial communities subjected to long-term experimental warming based on pyrosequencing data of 16 S rRNA genes. We showed that the constructed MENs under both warming and unwarming conditions exhibited topological features of scale free, small world and modularity, which were consistent with previously described molecular ecological networks. Eigengene analysis indicated that the eigengenes represented the module profiles relatively well. In consistency with many other studies, several major environmental traits including temperature and soil pH were found to be important in determining network interactions in the microbial communities examined. To facilitate its application by the scientific community, all these methods and statistical tools have been integrated into a comprehensive Molecular Ecological Network Analysis Pipeline (MENAP), which is open

  8. Molecular Gastronomy in Spain

    OpenAIRE

    García-Segovia, Purificación; Garrido, María Dolores; Vercet Tormo, Antonio; Arboleya, Juan Carlos; FISZMAN DAL SANTO, SUSANA; Martínez Monzó, Javier; Laguarda, Sergio; Palacios, Victor; Ruiz Carrascal, Jorge

    2014-01-01

    [EN] Beyond the overwhelming international success of Ferrán Adria, Spain has been one of the countries with a more active implication in molecular gastronomy as a scientific discipline but also in the use of ingredients, technologies, and equipment from the scientificand technological universe in the culinary area. Nowadays, this is a well-established discipline in Spain, with a number of research groups covering related topics, several companies commercializing appliances and additives worl...

  9. Communication: Molecular gears

    Energy Technology Data Exchange (ETDEWEB)

    Burnell, E. Elliott, E-mail: elliott.burnell@ubc.ca [Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1 (Canada); Lange, Cornelis A. de, E-mail: c.a.de.lange@vu.nl [Atomic, Molecular and Laser Physics, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands); Meerts, W. Leo, E-mail: leo.meerts@science.ru.nl [Atomic, Molecular and Laser Physics, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands); Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, NL-6525 AJ Nijmegen (Netherlands)

    2016-09-07

    The {sup 1}H nuclear magnetic resonance spectrum of hexamethylbenzene orientationally ordered in the nematic liquid crystal ZLI-1132 is analysed using covariance matrix adaptation evolution strategy. The spectrum contains over 350 000 lines with many overlapping transitions, from which four independent direct dipolar couplings are obtained. The rotations of the six methyl groups appear to be correlated due to mutual steric hindrance. Adjacent methyl groups show counter-rotating or geared motion. Hexamethylbenzene thus behaves as a molecular hexagonal gear.

  10. Atomic and molecular theory

    Energy Technology Data Exchange (ETDEWEB)

    Inokuti, Mitio.

    1990-01-01

    The multifaceted role of theoretical physics in understanding the earliest stages of radiation action is discussed. Scientific topics chosen for the present discourse include photoabsorption, electron collisions, and ionic collisions, and electron transport theory, Connections of atomic and molecular physics with condensed-matter physics are also discussed. The present article includes some historical perspective and an outlook for the future. 114 refs., 3 figs.

  11. Interaction of the model alkyltrimethylammonium ions with alkali halide salts: an explicit water molecular dynamics study

    Directory of Open Access Journals (Sweden)

    M. Druchok

    2013-01-01

    Full Text Available We present an explicit water molecular dynamics simulation of dilute solutions of model alkyltrimethylammonium surfactant ions (number of methylene groups in the tail is 3, 5, 8, 10, and 12 in mixture with NaF, NaCl, NaBr, and NaI salts, respectively. The SPC/E model is used to describe water molecules. Results of the simulation at 298 K are presented in form of the radial distribution functions between nitrogen and carbon atoms of CH2 groups on the alkyltrimethylammonium ion, and the counterion species in the solution. The running coordination numbers between carbon atoms of surfactants and counterions are also calculated. We show that I- counterion exhibits the highest, and F- the lowest affinity to "bind" to the model surfactants. The results are discussed in view of the available experimental and simulation data for this and similar solutions.

  12. Muscle K+, Na+, and Cl- disturbances and Na+-K+ pump inactivation: implications for fatigue

    DEFF Research Database (Denmark)

    McKenna, Michael J; Bangsbo, Jens; Renaud, Jean-Marc

    2008-01-01

    (+)-ATPase activity during exercise stabilizes Na(+) and K(+) concentration gradients and membrane excitability and thus protects against fatigue. However, during intense contraction some Na(+)-K(+) pumps are inactivated and together with further ionic disturbances, likely precipitate muscle fatigue.......Membrane excitability is a critical regulatory step in skeletal muscle contraction and is modulated by local ionic concentrations, conductances, ion transporter activities, temperature, and humoral factors. Intense fatiguing contractions induce cellular K(+) efflux and Na(+) and Cl(-) influx......, causing pronounced perturbations in extracellular (interstitial) and intracellular K(+) and Na(+) concentrations. Muscle interstitial K(+) concentration may increase 1- to 2-fold to 11-13 mM and intracellular K(+) concentration fall by 1.3- to 1.7-fold; interstitial Na(+) concentration may decline by 10 m...

  13. Metallic Na formation in NaCl crystals with irradiation of electron or vacuum ultraviolet photon

    Energy Technology Data Exchange (ETDEWEB)

    Owaki, Shigehiro [Osaka Prefecture Univ., Sakai, Osaka (Japan). Coll. of Integrated Arts and Sciences; Koyama, Shigeko; Takahashi, Masao; Kamada, Masao; Suzuki, Ryouichi

    1997-03-01

    Metallic Na was formed in NaCl single crystals with irradiation of a variety of radiation sources and analyzed the physical states with several methods. In the case of irradiation of 21 MeV electron pulses to the crystal blocks, the optical absorption and lifetime measurement of positron annihilation indicated appearance of Na clusters inside. Radiation effects of electron beam of 30 keV to the crystals in vacuum showed the appearance of not only metallic Na but atomic one during irradiation with Auger electron spectroscopy. Intense photon fluxes in vacuum ultraviolet region of synchrotron radiation were used as another source and an analyzing method of ultraviolet photoelectron spectroscopy. The results showed the metallic Na layered so thick that bulk plasmon can exist. (author)

  14. Hydrolysis of Rice Straw Pretreated by Na2SO3 Over Fe-resin/NaCl

    Directory of Open Access Journals (Sweden)

    YANG Hui

    2017-05-01

    Full Text Available To increase the conversion of rice straw(RS and the yield of products, we employed three methods, which were ultrasonic wave, steam explosion and Na2SO3 pretreatment to pretreat RS(the treated RS noted as CS-RS, ZQ-RS and Na2SO3-RS, respectively and found that Na2SO3 treatment was the best pretreatment method based on XRD, SEM, elemental analysis and content of cellulose, hemicellulose and lignin. The conversion of Na2SO3-RS and the yield of total reducing sugar(TRS and levulinic acid(LA were 97.3%, 29.6% and 13.5%, respectively by 10% Fe-resin in 3.3% NaCl solution under 200 ℃.

  15. Na-ion dynamics in Quasi-1D compound NaV2O4

    International Nuclear Information System (INIS)

    Månsson, M; Umegaki, I; Nozaki, H; Higuchi, Y; Sugiyama, J; Kawasaki, I; Watanabe, I; Sakurai, H

    2014-01-01

    We have used the pulsed muon source at ISIS to study high-temperature Na-ion dynamics in the quasi-one-dimensional (Q1D) metallic antiferromagnet NaV 2 O 4 . By performing systematic zero-field and longitudinal-field measurements as a function of temperature we clearly distinguish that the hopping rate increases exponentially above T diff ≈ 250 K. The data is well fitted to an Arrhenius type equation typical for a diffusion process, showing that the Na-ions starts to be mobile above T diff . Such results make this compound very interesting for the tuning of Q1D magnetism using atomic-scale ion-texturing through the periodic potential from ordered Na-vacancies. Further, it also opens the door to possible use of NaV 2 O 4 and related compounds in energy related applications

  16. Summer sudden Na number density enhancements measured with the ALOMAR Weber Na Lidar

    Directory of Open Access Journals (Sweden)

    D. Heinrich

    2008-05-01

    Full Text Available We present summer Na-densities and atmospheric temperatures measured 80 to 110 km above the Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR. The Weber Na Lidar is part of ALOMAR, located at 69° N in Norway, 150 km north of the Arctic Circle. The sun does not set here during the summer months, and measurements require a narrowband Faraday Anomalous Dispersion Optical Filter (FADOF.

    We discuss an observed sudden enhancement in the Na number density around 22:00 UT on 1 to 2 June 2006. We compare this observation with previous summer measurements and find a frequent appearance of Na number density enhancements near local midnight. We describe the time of appearance, the altitude distribution, the duration and the strength of these enhancements and compare them to winter observations. We investigate possible formation mechanisms and, as others before, we find a strong link between these Na number density enhancements and sporadic E layers.

  17. Summer sudden Na number density enhancements measured with the ALOMAR Weber Na Lidar

    Directory of Open Access Journals (Sweden)

    D. Heinrich

    2008-05-01

    Full Text Available We present summer Na-densities and atmospheric temperatures measured 80 to 110 km above the Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR. The Weber Na Lidar is part of ALOMAR, located at 69° N in Norway, 150 km north of the Arctic Circle. The sun does not set here during the summer months, and measurements require a narrowband Faraday Anomalous Dispersion Optical Filter (FADOF. We discuss an observed sudden enhancement in the Na number density around 22:00 UT on 1 to 2 June 2006. We compare this observation with previous summer measurements and find a frequent appearance of Na number density enhancements near local midnight. We describe the time of appearance, the altitude distribution, the duration and the strength of these enhancements and compare them to winter observations. We investigate possible formation mechanisms and, as others before, we find a strong link between these Na number density enhancements and sporadic E layers.

  18. Molecular basis of alcoholism.

    Science.gov (United States)

    Most, Dana; Ferguson, Laura; Harris, R Adron

    2014-01-01

    Acute alcohol intoxication causes cellular changes in the brain that last for hours, while chronic alcohol use induces widespread neuroadaptations in the nervous system that can last a lifetime. Chronic alcohol use and the progression into dependence involve the remodeling of synapses caused by changes in gene expression produced by alcohol. The progression of alcohol use, abuse, and dependence can be divided into stages, which include intoxication, withdrawal, and craving. Each stage is associated with specific changes in gene expression, cellular function, brain circuits, and ultimately behavior. What are the molecular mechanisms underlying the transition from recreational use (acute) to dependence (chronic)? What cellular adaptations result in drug memory retention, leading to the persistence of addictive behaviors, even after prolonged drug abstinence? Research into the neurobiology of alcoholism aims to answer these questions. This chapter will describe the molecular adaptations caused by alcohol use and dependence, and will outline key neurochemical participants in alcoholism at the molecular level, which are also potential targets for therapy. © 2014 Elsevier B.V. All rights reserved.

  19. Molecular symmetry and spectroscopy

    CERN Document Server

    Bunker, Philip; Jensen, Per

    2006-01-01

    The first edition, by P.R. Bunker, published in 1979, remains the sole textbook that explains the use of the molecular symmetry group in understanding high resolution molecular spectra. Since 1979 there has been considerable progress in the field and a second edition is required; the original author has been joined in its writing by Per Jensen. The Material of the first edition has been reorganized and much has been added. The molecular symmetry group is now introduced early on, and the explanation of how to determine nuclear spin statistical weights has been consolidated in one chapter, after groups, symmetry groups, character tables and the Hamiltonian have been introduced. A description of the symmetry in the three-dimensional rotation group K(spatial), irreducible spherical tensor operators, and vector coupling coefficients is now included. The chapters on energy levels and selection rules contain a great deal of material that was not in the first edition (much of it was undiscovered in 1979), concerning ...

  20. Molecular markers in glioma.

    Science.gov (United States)

    Ludwig, Kirsten; Kornblum, Harley I

    2017-09-01

    Gliomas are the most malignant and aggressive form of brain tumors, and account for the majority of brain cancer related deaths. Malignant gliomas, including glioblastoma are treated with radiation and temozolomide, with only a minor benefit in survival time. A number of advances have been made in understanding glioma biology, including the discovery of cancer stem cells, termed glioma stem cells (GSC). Some of these advances include the delineation of molecular heterogeneity both between tumors from different patients as well as within tumors from the same patient. Such research highlights the importance of identifying and validating molecular markers in glioma. This review, intended as a practical resource for both clinical and basic investigators, summarizes some of the more well-known molecular markers (MGMT, 1p/19q, IDH, EGFR, p53, PI3K, Rb, and RAF), discusses how they are identified, and what, if any, clinical relevance they may have, in addition to discussing some of the specific biology for these markers. Additionally, we discuss identification methods for studying putative GSC's (CD133, CD15, A2B5, nestin, ALDH1, proteasome activity, ABC transporters, and label-retention). While much research has been done on these markers, there is still a significant amount that we do not yet understand, which may account for some conflicting reports in the literature. Furthermore, it is unlikely that the investigator will be able to utilize one single marker to prospectively identify and isolate GSC from all, or possibly, any gliomas.