Resummation of the Divergent Perturbation Series for a Hydrogen Atom in an Electric Field

We consider the resummation of the perturbation series describing the energy displacement of a hydrogenic bound state in an electric field (known as the Stark effect or the LoSurdo-Stark effect), which constitutes a divergent formal power series in the electric field strength. The perturbation series exhibits a rich singularity structure in the Borel plane. Resummation methods are presented which appear to lead to consistent results even in problematic cases where isolated singularities or branch cuts are present on the positive and negative real axis in the Borel plane. Two resummation prescriptions are compared: (i) a variant of the Borel-Pade resummation method, with an additional improvement due to utilization of the leading renormalon poles (for a comprehensive discussion of renormalons see [M. Beneke, Phys. Rep. vol. 317, p. 1 (1999)]), and (ii) a contour-improved combination of the Borel method with an analytic continuation by conformal mapping, and Pade approximations in the conformal variable. The singularity structure in the case of the LoSurdo-Stark effect in the complex Borel plane is shown to be similar to (divergent) perturbative expansions in quantum chromodynamics.Comment: 14 pages, RevTeX, 3 tables, 1 figure; numerical accuracy of results enhanced; one section and one appendix added and some minor changes and additions; to appear in phys. rev.

Geophysical and atmospheric evolution of habitable planets

The evolution of Earth-like habitable planets is a complex process that depends on the geodynamical and geophysical environments. In particular, it is necessary that plate tectonics remain active over billions of years. These geophysically active environments are strongly coupled to a planet's host star parameters, such as mass, luminosity and activity, orbit location of the habitable zone, and the planet's initial water inventory. Depending on the host star's radiation and particle flux evolution, the composition in the thermosphere, and the availability of an active magnetic dynamo, the atmospheres of Earth-like planets within their habitable zones are differently affected due to thermal and nonthermal escape processes. For some planets, strong atmospheric escape could even effect the stability of the atmosphere

Epstein-Barr virus: clinical and epidemiological revisits and genetic basis of oncogenesis

Epstein-Barr virus (EBV) is classified as a member in the order herpesvirales, family herpesviridae, subfamily gammaherpesvirinae and the genus lymphocytovirus. The virus is an exclusively human pathogen and thus also termed as human herpesvirus 4 (HHV4). It was the first oncogenic virus recognized and has been incriminated in the causation of tumors of both lymphatic and epithelial nature. It was reported in some previous studies that 95% of the population worldwide are serologically positive to the virus. Clinically, EBV primary infection is almost silent, persisting as a life-long asymptomatic latent infection in B cells although it may be responsible for a transient clinical syndrome called infectious mononucleosis. Following reactivation of the virus from latency due to immunocompromised status, EBV was found to be associated with several tumors. EBV linked to oncogenesis as detected in lymphoid tumors such as Burkitt's lymphoma (BL), Hodgkin's disease (HD), post-transplant lymphoproliferative disorders (PTLD) and T-cell lymphomas (e.g. Peripheral T-cell lymphomas; PTCL and Anaplastic large cell lymphomas; ALCL). It is also linked to epithelial tumors such as nasopharyngeal carcinoma (NPC), gastric carcinomas and oral hairy leukoplakia (OHL). In vitro, EBV many studies have demonstrated its ability to transform B cells into lymphoblastoid cell lines (LCLs). Despite these malignancies showing different clinical and epidemiological patterns when studied, genetic studies have suggested that these EBV- associated transformations were characterized generally by low level of virus gene expression with only the latent virus proteins (LVPs) upregulated in both tumors and LCLs. In this review, we summarize some clinical and epidemiological features of EBV- associated tumors. We also discuss how EBV latent genes may lead to oncogenesis in the different clinical malignancie

Pt L 2-3- Edge X-ray Absorption Spectroscopy Investigation Of Zerovalent [pt(pph 3) 2(h 2-l)] {l = C2h 4, C 60 And C 2(cn) 4} Compounds

X-ray absorption spectra at the Pt L 2-3-edges have been measured for three [Pt(PPh 3) 2(h 2-L)] {L= C 2H 4, C 60 and C 2(CN) 4} compounds. The spectral features are effective for measuring the p*-acid strength of ligands (L) coordinated to the Pt(PPh 3) 2 fragment. The energies of the d φ-orbitals are quantitatively determined using the difference between the edge jumping and the edge maximum shifts of the L 2, 3-white lines in the second derivatives of the spectra. The d p-orbital energies follow the order [Pt(PPh 3) 2(h 2-C 2H 4)] < [Pt(PPh 3) 2(h 2-C 60)] < [Pt(PPh 3) 2{h 2-C 2(CN) 4}]. These d φ-orbital energies are in good agreement with the changes in the bound olefinic carbon bond lengths and the 31P NMR chemical shifts of the coordinated phosphines. Furthermore, the experimental values are in good agreement with available dp-orbital interaction energy terms calculated using density functional theory for model [Pt(PH 3) 2(h 2-L)] compounds. © 2012 Sociedade Brasileira de Química.2313238Bianconi, A., Garcia, J., Benfatto, M., (1988) Top. Curr. Chem, 145, p. 29Bianconi, A., (1988) X-Ray Absorption: Principles, Applications, Techniques of EXAFS, SEXAFS and XANES, , Koningsberger, D. C.Prins, R., eds Wiley: New YorkPenner-Hahn . J, E., (1999) Coord. Chem. Rev, 192, p. 1101Pantelouris, A., Küper, G., Hormes, J., Feldmann, C., Jansen, M., (1995) J. Am. Chem. Soc, 117, p. 11749Brown, M., Peierls, R.E., Stern, E.A., (1977) Phys. Rev. B: Condens. Matter Mater. Phys., 15, p. 738Hitchcock, A.P., Wen, A.T., Rühl, E., (1990) Chem. Phys, 147, p. 51Richtmyer, F.K., Barnes, S.W., Ramberg, E., (1934) Phys. Rev, 46, p. 843Ramaker, D.E., Mojet, B.L., Oostenbrink, M.T.G., Miller, J.T., Koningsberger, D.C., (1999) Phys. Chem. Chem. Phys, 1, p. 2293Behrens, P., Assmann, S., Bilow, U., Linke, C., Jansen, M., (1999) Z. Anorg. Allg. Chem, 625, p. 111Behrens, P., (1992) Solid State Commun, 81, p. 235Naftel, S.J., Bzowski, A., Sham, T.K., (1999) J. Alloys Compd, 283, p. 5Drube, W., Treusch, R., Sham, T.K., Bzowski, A., Soldatov, A.V., (1998) Phys. Rev. B: Condens. Matter Mater. Phys, 58, p. 6871Jeon, Y., Qi, B.Y., Lu, F., Croft, M., (1989) Phys. Rev. B: Condens. Matter Mater. Phys, 40, p. 1538Dewar, M.J.S., (1951) Bull. Soc. Chim. Fr, 18, pp. C79Chatt, J., Duncanson, L.A., J. Chem. Soc, 1953, p. 2939Albright, T.A., Hoffmann, R., Thibeault, J.C., Thorn, D.L., (1979) J. Am. Chem. Soc, 101, p. 3801Ziegler, T., (1985) Inorg. Chem, 24, p. 1547Morokuma, K., Borden, W.T., (1991) J. Am. Chem. Soc, 113, p. 1912Nunzi, F., Sgamellotti, A., Re, N., Floriani, C., (1999) J. Chem. Soc., Dalton Trans, 3487Uddin, J., Dapprich, S., Frenking, G., Yates, B.F., (1999) Organometallics, 18, p. 457Fujimoto, H., Nakao, Y., Fukui, K., (1993) J. Mol. Struct, 300, p. 425Koga, N., Morokuma, K., (1993) Chem. Phys. Lett, 202, p. 330Lichtenberger, D.L., Wright, L.L., Gruhn, N.E., Rempe, M.E., (1994) J. Organomet. Chem, 478, p. 213López, J.A., Mealli, C., (1994) J. Organomet. Chem, 478, p. 161Nunzi, F., Sgamellotti, A., Re, N., Floriani, C., (2000) Organometallics, 19, p. 1628Craciun, R., Vincent, A.J., Shaughnessy, K.H., Dixon, D.A., (2010) Inorg. Chem, 49, p. 5546Li, J., Schreckenbach, G., Ziegler, T., (1995) Inorg. Chem, 34, p. 3245C 60 Is Herein Treated As An Electron-deficient PolyalkeneJeon, Y., Chen, J., Croft, M., (1994) Phys. Rev. B: Condens. Matter Mater. Phys, 50, p. 6555Benfield, R.E., Grandjean, D., Kröll, M., Pugin, R., Sawitowski, T., Schmid, G., (2001) J. Phys. Chem. B, 105, p. 1961Outka, D.A., Stöhr, J., (1988) J. Chem. Phys, 88, p. 3539Mansour, A.N., Cook Jr., J.W., Sayers, D.E., (1984) J. Phys. Chem, 88, p. 2330Choy, J.-H., Kim, D.-K., Demazeau, G., Jung, D.-Y., (1994) J. Phys. Chem, 98, p. 6258Pease, D.M., Fasihuddin, A., Daniel, M., Budnick, J.I., (2001) Ultramicroscopy, 88, p. 1Sham, T.K., (1985) Phys. Rev. B: Condens. Matter Mater. Phys, 31, p. 1888Sham, T.K., (1987) Solid State G Commun, 64, p. 1103De Groot, F.M.F., Hu, Z.W., Lopez, M.F., Kaindl, O., Guillt, F., (1994) Tronc M J. Chem. Phys, 101, p. 6570Qi, B., Perez, I., Ansari, P.H., Lu, F., Croft, M., (1987) Phys. Rev. B: Condens. Matter Mater. Phys, 36, p. 2972Sham, T.K., (1985) Phys. Rev. B: Condens. Matter Mater. Phys, 31, p. 1903Lytle, F.W., Greegor, R.B., (1990) Appl. Phys. Lett, 56, p. 192Wang, W.-C., Chen, Y., Hu, T.-D., (1994) Phys. Status Solidi B, 186, p. 545Costain, C.C., Stoicheff, B.P., (1959) J. Chem. Phys, 30, p. 777Fedurco, M., Olmstead, M.M., Fawcett, W.R., (1995) Inorg. Chem, 34, p. 390Bekoe, D.A., Trueblood, K.N., (1960) Z. Kristallogr, 113, p. 1Asaro, F., Lenarda, M., Pellizer, G., Storaro, L., (2000) Spectrochim. Acta, Part A, 56, p. 2167Pellizer, G., Graziani, M., Lenarda, M., (1983) Polyhedron, 2, p. 657Berger, S., Braun, S., Kalinnowski, H.-O., (1977) NMR Spectroscopy of the Non-Metallic Elements, p. 709. , Wiley: ChichesterCheng, P.-T., Nyburg, S.C., (1972) Can. J. Chem, 50, p. 912Bombieri, G., Forselli, E., Panattoni, C., Graziani, R., Bandoli, G., (1970) J. Chem. Soc. A, 1313Karhánek, D., Kacer, P., Kuzma, M., Splíchalová, J., Cervený, L., (2007) J. Mol. Model, 13, p. 1009Frenking, G., Fröhlich, N., (2000) Chem. Rev, 100, p. 717. , and references thereinNagel, U., (1982) Chem. Ber, 115, p. 1998Fagan, P.J., Calabrese, J.C., Malone, B., (1991) Science, 252, p. 1160Baddley, W.H., Venanzi, L.M., (1966) Inorg. Chem, 5, p. 3

Ese Studies Of Pristine Paramagnetic Species Of Ceo Powder Samples

Paramagnetic centers in pristine polycrystalline C60 samples are investigated at room temperature using continuous wave electron paramagnetic resonance (CW-EPR) and electron spin-echo spectroscopy. Two paramagnetic species, with same measured g-values, are separated using echo-detected EPR and the PEANUT pulse scheme. Electron-spin nutation frequencies for both species are measured using the latter technique. For the doublet species, usually observed by CW-EPR, nutation frequency is 7.5 MHz. The second species, with a nutation frequency of 10.4 MHz, is a spin triplet. This species is solely revealed by pulse methods and corresponds to dipolar coupling of C60 paramagnetic centers located at the diagonals of the fullerene fee lattice. © 2000 American Chemical Society.104611621164Kroto, H.W., Health, I.R., O'Brian, S.C., Curl, R.F., Smalley, R.E., (1985) Nature, 318, p. 162Krätschmer, M.J., Murphy, D.W., Fleming, R.M., Tycko, R., Ramirez, A.P., Siegrist, T., Dabbagh, G., Barret, S.E., (1990) Nature, 347, p. 354

Solid-state Structural Studies On Amorphous Platinum-fullerene[60] Compounds [ptnc60] (n = 1,2)

Homoleptic amorphous platinum-fullerene compounds were synthesized from low-valent platinum precursors. Both variation of precursor and temperature of synthesis lead to different phases. Simultaneous observation of symmetric and antisymmetric fullerene vibrational modes in the platinum-fullerene IR and resonant Raman spectra support evidence for dimer and oligomer formations. Doublet splitting of fullerene (Ih point group symmetry) F1u modes and observation of previously IR silent modes also indicate substantial local disorder at the fullerene moiety. X-band CW-EPR measurements, using the microwave power saturation technique, allows observation of at least two different relaxation behaviours, that are attributed to activation of efficient relaxation pathways in the compounds synthesized at 25°C. These processes are absent in fullerene[60] and much less effective in the platinum compound obtained at -45°C. © 2000 Elsevier Science B.V. All rights reserved.27202/03/15127130Bowser, J.R., (1994) Adv. Organomet. Chem., 36, p. 57Nagashima, H., Nakaoka, A., Saito, Y., Kato, M., Kawanishi, T., Itoh, K., (1992) J. Chem. Soc., Chem. Commun., p. 377Dias, G.H.M., (1995) Quím. Nova, 18, p. 592Moseley, K., Maitlis, P.M., (1971) Chem. Commun., p. 982Spencer, J.L., (1979) Inorg. Synth., 19, p. 213Kuzmany, H., Matus, M., Burger, B., Winter, J., (1994) Adv. Mater., 6, p. 731Martin, M.C., Koller, D., Rosenberg, A., Kendziora, C., Mihaly, L., (1995) Phys. Rev. B, 51, p. 3210Hoffmann, S.K., Hilczer, W., Kempinski, W., Stankowski, J., (1995) Solid State Commun., 93, p. 197Golding, B., Graebner, J.E., (1981) Topics in Current Physics 24, Amorphous Solids, , W.A. Phillips (Ed.), Springer, BerlinSchmith-Rohr, K., Spiess, H.W., (1994) Multidimensional Solid State NMR and Polymers, , Academic Press, New York, Chapter 7Pinhal, N.M., Vugman, N.V., Herbst, M.H., Dias, G.H.M., (2000) J. Phys. Chem. A, 104, p. 116

Enthalpy Of Solution Of Fullerene[60] In Some Aromatic Solvents

Enthalpies of solution (Δ solnH θ) of fullerene[60] in benzene, toluene, bromobenzene, 1,2-dichlorobenzene and nitrobenzene have been measured in a Precision Solution Calorimeter at 298 K, by using the ampoule breaking technique. The dissolution of C 60 in these aromatic organic solvents was observed to be exothermic, with exception of benzene and nitrobenzene, in which the enthalpy is close to zero. From the experimental values of Δ solnH θ and solubility data of C 60 from the literature, Δ solnG θ and Δ solnS θ were calculated. We attempted to correlate (Δ solnH θ) of C 60 in these solvents with the solubility, Hildebrand's solubility parameter and polarizability parameter. Thermodynamic data suggest that the process of dissolution of C 60 in the studied aromatic solvents is entropically controlled. © 2004 Elsevier B.V. All rights reserved.1181-3913Fowler, P.W., Woolrich, J., (1986) Chem. Phys. Lett., 127, p. 78Haddon, R.C., Brus, L.E., Raghavachari, K., (1986) Chem. Phys. Lett., 125, p. 459Sivaraman, N., Dhamodaran, R., Kaliappan, I., (1994) Fullerene Sci. Technol., 2 (3), p. 233Ruoff, R.S., Tse, D.S., Malhotra, R., Lorents, D.C., (1993) J. Phys. Chem., 97, p. 3379Ruoff, R.S., Malhotra, R., Huestis, D.L., (1993) Nature, 362, p. 140Zhou, X., Gu, Z., Wu, Y., (1994) Carbon, 32, p. 935Ruelle, P., Farina-Cuendet, A., Kesselring, U.W., (1995) J. Chem. Soc., Chem. Commun., p. 1161Catalán, J., Saiz, J.L., Laynez, J.L., Jagerovic, N., Elguero, J., (1995) Angew. Chem., Int. Ed. Engl., 34, p. 105Marcus, Y., Smith, A.L., Korobov, M.V., Mirakyan, A.L., Avramenko, N.V., Stukalim, E.B., (2001) J. Phys. Chem., B, 105, p. 2499Korobov, M.V., Mirakyan, A.L., Avramenko, N.V., Olofsson, G., Smith, A.L., Ruoff, R.S., (1999) J. Phys. Chem., B, 103, p. 1339Kroto, H.W., (1987) Nature, 329, p. 529Hildebrand, J.H., Prausnitz, J.M., Scott, J.L., (1970) Regular and Related Solutions, , Van Nostrand Reinhold New YorkPrausnitz, J.M., Lichtenberger, R.N., De Azevedo, E., (1986) Molecular Thermodynamics of Fluid-phase Equilibria, , Prentice Hall Englewood Cliffs, NJMatheus, C.K., Sai Baba, M., Lakshmi Narasimhan, T.S., Balasubramanian, R., Sivaranan, N., Sirinivasan, T.G., Vasudeva Rao, P.R., (1992) J. Phys. Chem., 96, p. 3566Kraetschmer, W., Lamb, L.D., Fostiropoulos, K., Huffman, D.R., (1990) Nature, 347, p. 354Billups, W.E., Cinfolini, M.A., (1993) Buckminsterfullerene, pp. 29-34. , VCH WeinheimSun, Y.P., Ma, B., (1995) Chem. Phys. Lett., 236, p. 285Sun, Y.P., Ma, B., Lawson, G.E., (1995) Chem. Phys. Lett., 233, p. 57Lichtenberger, D.L., Wright, L.L., Gruhn, N.E., Rempe, M.E., (1994) J. Organomet. Chem., 478, p. 213Takeharu, H., Manabu, Y., Yoshimasa, F., (1997) Angew. Chem., Int. Ed. Engl., 36, p. 259Palit, D.K., Ghosh, H.N., Pal, H., Sapre, A.V., Mittal, J.P., (1992) Chem. Phys. Lett., 198, p. 113Bowser, J.R., (1994) Adv. Organomet. Chem., 36, p. 57Fowler, P.W., Ceulemans, A., (1995) J. Phys. Chem., 99, p. 508Herrington, E.F.G., (1974) Pure Appl. Chem., 40, p. 391Thermometric Catalogue, , Spjutvägen 5A, S-175 61 Järfälla, SwedenWudl, F., (1992) A.C.S. Symp. Ser., 481, p. 161Taylor, R., Walton, D.R.M., (1993) Nature, 363, p. 685Sivaraman, N., Dhamodaran, R., Kaliappan, I., Srinivasan, T.G., Vasudeva Rao, P.R., Matheus, C.K., (1994) Fullerene Sci. Technol., 2 (30), p. 233Ruoff, R.S., Olofsson, G., Wadso, I., (1995) Recent Advances in the Chemistry and Physics of Fullerenes and Related Materials, 95 (10), p. 1519. , K.M. Kadish R.S. Ruoff The Electrochemical Society Pennington, NJOlofsson, G., Wädso, I., Ruoff, R.S., (1996) Recent Advances in the Chemistry and Principles of Fullerene and Related Materials, 96 (10), p. 18. , K.M. Kadish R.S. Ruoff Eletrochemical Society Proceedings Series Pennington, NJYin, J., Wang, B.H., Li, Z.F., Zhang, Y.M., Zhou, X.H., Gu, Z.N., (1996) J. Chem. Thermodyn., 28, p. 1145Smith, A.L., Walter, E., Korobov, M.V., Gurvich, O.L., (1996) J. Phys. Chem., 100, p. 6775Korobov, M.V., Mirakyan, A.L., Avramenko, N.V., Vallev, E.F., Neretin, I.S., Slovokhotov, Y.L., Smith, A.L., Ruoff, R.S., (1998) J. Phys. Chem., B, 102, p. 371Zhou, X., Liu, J., Jin, Z., Wu, Y., Gu, Z., Yin, J., Wang, B., Zhang, Y., (1995) Recent Advances in the Chemistry and Physics of Fullerenes and Related Materials, 95 (10), p. 1544. , K.M. Kadish R.S. Ruoff The Electrochemical Society Pennington, NJSmith, A.L., Li, D., King, B., Zimmerman, G., (1994) Recent Advances in the Chemistry and Physics of Fullerenes and Related Materials, 94 (24), p. 443. , K.M. Kadish R.S. Ruoff The Electrochemical Society Pennington, NJSivaraman, N., Dhamodaran, R., Kaliappan, I., Srinavasan, T.G., Vasudeva Rao, P.R., Mathews, C.K., (1994) Recent Advances in the Chemistry and Physics of Fullerenes and Related Materials, 94 (24), p. 156. , K.M. Kadish R.S. Ruoff The Electrochemical Society Pennington, N