26 research outputs found

    Heavy quarkonium: progress, puzzles, and opportunities

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    A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the BB-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b}, and b\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K. Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D. Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A. Petrov, P. Robbe, A. Vair

    Oral malignant melanoma of alveolar ridge

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    Malignancy of melanocytes, a pigment-producing cell, is referred as malignant melanoma (MM) which occur basically on skin and oral mucous membrane, but as well found in ears, eyes, gastrointestinal tract and genital mucosa. Oral melanomas has propensity to metastasise and invade more voluntarily than other malignant counterparts. Here we present a case of 52-year-old male patient with a chief symptom of blackening of gums in the upper front tooth region. In dental history, the patient revealed history of faulty artificial prosthesis fixed in the same region since 6 months. On the basis of a through clinical assessment, a provisional opinion of oral malignant melanoma, was prepared. On histopathological and immunohistochemical analysis with S-100 and homatropine methylbromide 45 the diagnosis of MM was confirmed.</jats:p

    Electrochemical, Ultrasensitive, and Selective Detection of Nitrite and H2O2: Novel Macrostructured Phthalocyanine with Composite MWCNTs on a Modified GCE

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    In the current study, the synthesis of tetra-4-(2methoxyphenoxy) carboxamide cobalt(II) amide-bridged phthalocyanine (CoTMePhCAPc) is described, as well as its characterization by Fourier transform infrared (FT-IR), UV-visible, and mass spectroscopy; powder X-ray diffraction (PXRD); thermogravimetric analysis (TGA); scanning electron microscopy (SEM); and electrochemistry. Sensing of nitrite (NO2-) and hydrogen peroxide (H2O2) simultaneously was done on CoTMePhCAPc with the composite multiwalled carbon nanotube (MWCNT)modified glassy carbon electrode (CoTMePhCAPc/MWCNT/ GCE) in the range of linear absorption (NO2- and H2O2: CV 50- 750, differential pulse voltammetry (DPV) 50-750, CA 50-500 nmol L-1), lower detection limit (NO2- and H2O2: CV 10.5 and 12.5, DPV 10.5 and 11.2, CA 6.0 and 5.5 nmol L-1), and sensitivity (NO2- and H2O2: CV 0.379 and 0.529, DPV 0.043 and 0.049, CA 0.033 and 0.040 mu A nM-1 cm-2). The composite electrode exhibits improved electrocatalytic behavior compared to modified electrodes for nitrite and H2O2. The CoTMePhCAPc/MWCNT/GCE sensor displays good selectivity even in the presence of an excess of interfering metal ions and biomolecules at the applied potentials of +400 mV (nitrite) and -400 mV (H2O2). Moreover, the fabricated sensor was studied with various phosphate-buffered saline (PBS) (pH 5-9) electrolyte solutions. The unknown H2O2 concentration in blood samples and apple juice and nitrite concentration in drinking water and butter leaf lettuce were all measured using the usual addition method. Docking analysis clearly indicates that the ligand shows excellent inhibition activity toward the three subjected protein molecules

    Differential cross sections for excitation of H2 by low-energy electron impact

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    Experimental and theoretical differential cross sections (DCS) for the electron-impact excitation of molecular hydrogen to the B S+u 1 sc Pu 3 sa S+g 3 sC Pu 1 sand the E(F) S+g 1 states are presented at incident energies near to threshold. The experimental DCSs were taken at incident energies of 14, 15, 16 and 17.5 eV and for scattering angles from 10° to 130°. The theoretical DCSs are from the convergent close-coupling method which has recently successfully modeled differential electron scattering from H2 when compared with available experiment at energies of 17.5 eV and above
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