Molecular and Electronic Structure of Electroactive Self-Assembled Monolayers

Self-assembled monolayers (SAMs) containing electroactive functional groups are excellent model systems for the formation of electronic devices by self-assembly. In particular ferrocene-terminated alkanethiol SAMs have been extensively studied in the past. However, there are still open questions related with their electronic structure including the influence of the ferrocene group in the SAM-induced work function changes of the underlying metal. We have thus carried out a thorough experimental and theoretical investigation in order to determine the molecular and electronic structure of ferrocene-terminated alkanethiol SAMs on Au surfaces. In agreement with previous studies we found that the Fc-containing alkanethiol molecules adsorb forming a thiolate bond with the Au surface with a molecular geometry 30 degrees tilted with respect to the surface normal. Measured surface coverages indicate the formation of a compact monolayer. On the other hand, contrary with previous observations, we found that the ferrocene group has little influence on the observed work function decrease which is largely determined by the alkanethiol. Furthermore, the ferrocene moiety lies 14 Å above the metal surface covalently bonded to the alkanethiol SAM and its HOMO is located at -1.6 eV below the Fermi level. Our results provide new valuable insight into the molecular and electronic structure of electroactive SAMs which are of fundamental importance in the field of molecular electronics.Fil: Méndez de Leo, Lucila Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: de la Llave, Ezequiel Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Scherlis Perel, Damian Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Williams, Federico Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentin

Lattice Green's function approach to the solution of the spectrum of an array of quantum dots and its linear conductance

In this paper we derive general relations for the band-structure of an array of quantum dots and compute its transport properties when connected to two perfect leads. The exact lattice Green's functions for the perfect array and with an attached adatom are derived. The expressions for the linear conductance for the perfect array as well as for the array with a defect are presented. The calculations are illustrated for a dot made of three atoms. The results derived here are also the starting point to include the effect of electron-electron and electron-phonon interactions on the transport properties of quantum dot arrays. Different derivations of the exact lattice Green's functions are discussed

Risk factors of death at patient with severe influenza A(H1N1) pneumonia

In a service evaluation assessment we retrospectively reviewed the notes of 70 adult patients admitted to the hospital and subsequently confirmed to have contracted H1 N1 between November and December 2009. all these patients have hospitalized in ICU Yekaterinburg city. We have defined risk factors of death at patient with severe influenza A(H1 N1) pneumonia the accuracy of each score in predicting outcome was assessed by plotting the receiver operating characteristic (ROC) curve, calculating the area under the ROC curve (AUC) with 95% Confidence intervals and calculating odds ratio (OR). Predictors high risk of death, in our trial, are APACHE II score > 6; SOFA score > 3; LIS score > 2,5; leukocytes numbers 6 баллов; S0FA> 3 баллов; US > 2,5 баллов; число лейкоцитов <2,7 х 109/л; их юных форм лейкоцитов <15 %; количество тромбоцитов <148 х 109/л и коэффициент оксигенации Pa02/Fi02 <268 мм.рт.ст. Из сопутствующей патологии наиболее значимое негативное влияние на течение заболевания оказывают ожирение — OШ =3,18 (95% ДИ 1.08-9,32), и ишемическая болезнь сердца - 0Ш=4,14 (95% Д И 1,31 -3,18)

On the tau-functions of the Degasperis-Procesi equation

The DP equation is investigated from the point of view of determinant-pfaffian identities. The reciprocal link between the Degasperis-Procesi (DP) equation and the pseudo 3-reduction of the $C_{\infty}$ two-dimensional Toda system is used to construct the N-soliton solution of the DP equation. The N-soliton solution of the DP equation is presented in the form of pfaffian through a hodograph (reciprocal) transformation. The bilinear equations, the identities between determinants and pfaffians, and the $\tau$-functions of the DP equation are obtained from the pseudo 3-reduction of the $C_{\infty}$ two-dimensional Toda system.Comment: 27 pages, 4 figures, Journal of Physics A: Mathematical and Theoretical, to be publishe

Estimation of necessity of performance and choice of optimum terms tracheostomy at carrying out ALV at patients with abdominal sepsis

For the purpose of a substantiation of necessity and optimum terms of performance tracheostomy at 96 patients with a abdominal sepsis, demanding carrying out long ALV the analysis of a clinical current of disease is made. From them to 59 patients (61,5 %) it is executed surgical top median tracheostomy in different terms ALV. At 37 patients (38,5 %) long ventilation of lungs was carried out through an endotracheal tube throughout all period of artificial respiratory support. It is established that tracheostomy performance at carrying out long ALV within 25 days in the general population of patients the abdominal sepsis has no conclusive clinical advantages before ventilation of lungs through a endotracheal tube tube. Early the tracheostomy does not reduce risk VAP, does not reduce duration ALV and stay time in DRIT. Term of carrying out of artificial respiratory support is not the main defining factor for decision-making. Indications to tracheostomy should be individualised proceeding from a concrete clinical situation.С целью обоснования необходимости и оптимальных сроков выполнения трахеостомии у 96 пациентов с абдоминальным сепсисом, требующих проведения длительной ИВЛ выполнен анализ клинического течения заболевания. Из них 59 пациентам (61,5%) выполнена хирургическая верхняя срединная трахеостомия в разные сроки ИВЛ. У 37 пациентов (38,5%) длительная вентиляция лёгких осуществлялась через эндотрахеальную трубку на протяжении всего периода искусственной респираторной поддержки. Установлено, что выполнение ТС при проведении длительной ИВЛ в пределах 25 дней в общей популяции пациентов АС не имеет неоспоримых клинических преимуществ перед вентиляцией лёгких через эндотрахеальную трубку. Ранняя ТС не снижает риск ВАП, не сокращает длительность ИВЛ и время пребывания в ОРИТ. Срок проведения искусственной респираторной поддержки не является главным определяющим фактором для принятия решения. Показания к трахеостомии должны быть индивидуализированы исходя из конкретной клинической ситуации

A direct method of solution for the Fokas-Lenells derivative nonlinear Schr\"odinger equation: I. Bright soliton solutions

We develop a direct method of solution for finding the bright $N$-soliton solution of the Fokas-Lenells derivative nonlinear Schr\"odinger equation. The construction of the solution is performed by means of a purely algebraic procedure using an elementary theory of determinants and does not rely on the inverse scattering transform method. We present two different expressions of the solution both of which are expressed as a ratio of determinants. We then investigate the properties of the solutions and find several new features. Specifically, we derive the formula for the phase shift caused by the collisions of bright solitons.Comment: To appear in J. Phys. A: Math. Theor. 45(2012) Ma

Gravitating discs around black holes

Fluid discs and tori around black holes are discussed within different approaches and with the emphasis on the role of disc gravity. First reviewed are the prospects of investigating the gravitational field of a black hole--disc system by analytical solutions of stationary, axially symmetric Einstein's equations. Then, more detailed considerations are focused to middle and outer parts of extended disc-like configurations where relativistic effects are small and the Newtonian description is adequate. Within general relativity, only a static case has been analysed in detail. Results are often very inspiring, however, simplifying assumptions must be imposed: ad hoc profiles of the disc density are commonly assumed and the effects of frame-dragging and completely lacking. Astrophysical discs (e.g. accretion discs in active galactic nuclei) typically extend far beyond the relativistic domain and are fairly diluted. However, self-gravity is still essential for their structure and evolution, as well as for their radiation emission and the impact on the environment around. For example, a nuclear star cluster in a galactic centre may bear various imprints of mutual star--disc interactions, which can be recognised in observational properties, such as the relation between the central mass and stellar velocity dispersion.Comment: Accepted for publication in CQG; high-resolution figures will be available from http://www.iop.org/EJ/journal/CQ

Supersymmetric QCD corrections to e+e−→tbˉH−e^+e^-\to t\bar{b}H^- and the Bernstein-Tkachov method of loop integration

The discovery of charged Higgs bosons is of particular importance, since their existence is predicted by supersymmetry and they are absent in the Standard Model (SM). If the charged Higgs bosons are too heavy to be produced in pairs at future linear colliders, single production associated with a top and a bottom quark is enhanced in parts of the parameter space. We present the next-to-leading-order calculation in supersymmetric QCD within the minimal supersymmetric SM (MSSM), completing a previous calculation of the SM-QCD corrections. In addition to the usual approach to perform the loop integration analytically, we apply a numerical approach based on the Bernstein-Tkachov theorem. In this framework, we avoid some of the generic problems connected with the analytical method.Comment: 14 pages, 6 figures, accepted for publication in Phys. Rev.

Quantum field theory and Hopf algebra cohomology

We exhibit a Hopf superalgebra structure of the algebra of field operators of quantum field theory (QFT) with the normal product. Based on this we construct the operator product and the time-ordered product as a twist deformation in the sense of Drinfeld. Our approach yields formulas for (perturbative) products and expectation values that allow for a significant enhancement in computational efficiency as compared to traditional methods. Employing Hopf algebra cohomology sheds new light on the structure of QFT and allows the extension to interacting (not necessarily perturbative) QFT. We give a reconstruction theorem for time-ordered products in the spirit of Streater and Wightman and recover the distinction between free and interacting theory from a property of the underlying cocycle. We also demonstrate how non-trivial vacua are described in our approach solving a problem in quantum chemistry.Comment: 39 pages, no figures, LaTeX + AMS macros; title changed, minor corrections, references update

Fluids and barriers of the CNS: a historical viewpoint

Tracing the exact origins of modern science can be a difficult but rewarding pursuit. It is possible for the astute reader to follow the background of any subject through the many important surviving texts from the classical and ancient world. While empirical investigations have been described by many since the time of Aristotle and scientific methods have been employed since the Middle Ages, the beginnings of modern science are generally accepted to have originated during the 'scientific revolution' of the 16th and 17th centuries in Europe. The scientific method is so fundamental to modern science that some philosophers consider earlier investigations as 'pre-science'. Notwithstanding this, the insight that can be gained from the study of the beginnings of a subject can prove important in the understanding of work more recently completed. As this journal undergoes an expansion in focus and nomenclature from cerebrospinal fluid (CSF) into all barriers of the central nervous system (CNS), this review traces the history of both the blood-CSF and blood-brain barriers from as early as it was possible to find references, to the time when modern concepts were established at the beginning of the 20th century