1,436 research outputs found

    Mononitration of durene

    Get PDF
    Reaction conditions under which the nitration of durene give predominantly, and in high yield, mononitrodurene (I), rather than dinitrodurene were found. The nitrating agent was No2+RF6-. Nitration with nitrosulfuric acid also gave mononitrodurene; however, byproducts such as 2.3.5.6-Me4C6HCH2C6H2Me3-2,4,5, were also formed. The NO2 PF6- gave an intermediate additional compound with durene. The reaction carried out with 3.6-dideuterodurene in D2O shows no isotope effect

    Assumptions that imply quantum dynamics is linear

    Full text link
    A basic linearity of quantum dynamics, that density matrices are mapped linearly to density matrices, is proved very simply for a system that does not interact with anything else. It is assumed that at each time the physical quantities and states are described by the usual linear structures of quantum mechanics. Beyond that, the proof assumes only that the dynamics does not depend on anything outside the system but must allow the system to be described as part of a larger system. The basic linearity is linked with previously established results to complete a simple derivation of the linear Schrodinger equation. For this it is assumed that density matrices are mapped one-to-one onto density matrices. An alternative is to assume that pure states are mapped one-to-one onto pure states and that entropy does not decrease.Comment: 10 pages. Added references. Improved discussion of equations of motion for mean values. Expanded Introductio

    Canonical Expansion of PT-Symmetric Operators and Perturbation Theory

    Full text link
    Let HH be any \PT symmetric Schr\"odinger operator of the type 2Δ+(x12+...+xd2)+igW(x1,...,xd) -\hbar^2\Delta+(x_1^2+...+x_d^2)+igW(x_1,...,x_d) on L2(Rd)L^2(\R^d), where WW is any odd homogeneous polynomial and gRg\in\R. It is proved that H\P H is self-adjoint and that its eigenvalues coincide (up to a sign) with the singular values of HH, i.e. the eigenvalues of HH\sqrt{H^\ast H}. Moreover we explicitly construct the canonical expansion of HH and determine the singular values μj\mu_j of HH through the Borel summability of their divergent perturbation theory. The singular values yield estimates of the location of the eigenvalues \l_j of HH by Weyl's inequalities.Comment: 20 page

    Der internistische Check-up

    Get PDF
    Zusammenfassung: Viele präventive Maßnahmen bei gesunden Erwachsenen werden in zunehmendem Maße durch Evidenz gestützt oder verworfen. Dabei sind v.a. die Beratung bezüglich Tabakabstinenz, indizierte Impfungen und das Screening in Bezug auf Übergewicht, hohen Blutdruck, Hyperlipidämie, Zervixkarzinom, kolorektales Karzinom und Mammakarzinom bewiesenermaßen wichtig und sinnvoll. Nicht empfohlen wird ein Screening für Bronchial-, Pankreas- und Ovarialkarzinom. Ein Screening für Diabetes mellitus beim jüngeren Erwachsenen, Schilddrüsenerkrankungen und Prostatakarzinom wird nicht routinemäßig empfohlen, sollte aber je nach persönlichem Risikoprofil im Sinne eines sog. "Case findings" erwogen werden. Aus ärztlicher Sicht ist es auch wichtig, auf mögliche nicht deklarierte Beweggründe für eine Check-up-Untersuchung einzugehen, um so mögliche "Hidden Agendas" der Konsultationen aufzudecke

    Distributional Borel Summability of Odd Anharmonic Oscillators

    Full text link
    It is proved that the divergent Rayleigh-Schrodinger perturbation expansions for the eigenvalues of any odd anharmonic oscillator are Borel summable in the distributional sense to the resonances naturally associated with the system

    Design of an N^7-Glycosylated Purine Nucleoside for Recognition of GC Base Pairs by Triple Helix Formation

    Get PDF
    Pyrimidine oligodeoxyribonucleotides bind in the major groove of DNA parallel to the purine Watson-Crick strand by formation of specific hydrogen bonds between thymine and adenine (T•AT triplet) and protonated cytosine and guanine (C+GC triplet) on the Hoogsteen face of the purine base. Alternatively, purine oligodeoxyribonucleotides bind in an antiparallel orientation relative to the purine Watson-Crick strand by formation of G•GC and A•AT triplets. The prerequisite protonation of cytosine in C+GC triplets leads to a considerable pH dependence in the binding affinity of C-containing oligodeoxyribonucleotides (Figure 1). Substitution of 5-methylcytosine (^mC) for cytosine results in increased binding affinities near physiological pH. In an attempt to eliminate the necessity for protonation, recent efforts have been directed toward the synthesis of nonnatural nucleosides which display the hydrogen bonding functionality of protonated cytosine

    28-jähriger Patient mit erfolgreich behandelter dilatativer Kardiomyopathie

    Get PDF
    Zusammenfassung: Ein 28-jähriger Patient wurde mit dekompensierter Herzinsuffizienz notfallmäßig zugewiesen. In der Vorgeschichte bestand ein hypogonadotroper Hypogonadismus. Echokardiographisch fand sich eine dilatative Kardiomyopathie. Ein erhöhtes Serumferritin und eine Eisenüberladung in der Leberbiopsie ließen eine hereditäre Hämochromatose vermuten. Die kardiale Beteiligung konnte mittels Magnetresonanztomographie nachgewiesen werden. Genetische Abklärungen ergaben eine homozygote Mutation für G320V und bewiesen eine juvenile Hämochromatose. Eine Aderlasstherapie führte innerhalb eines Jahres zur Normalisierung des Eisenstatus und der kardialen Pumpfunktio

    Free Fermionic Heterotic Model Building and Root Systems

    Full text link
    We consider an alternative derivation of the GSO Projection in the free fermionic construction of the weakly coupled heterotic string in terms of root systems, as well as the interpretation of the GSO Projection in this picture. We then present an algorithm to systematically and efficiently generate input sets (i.e. basis vectors) in order to study Landscape statistics with minimal computational cost. For example, the improvement at order 6 is approximately 10^{-13} over a traditional brute force approach, and improvement increases with order. We then consider an example of statistics on a relatively simple class of models.Comment: Standard Latex, 12 page

    Integrating Data on Ethnicity, Geography, and Conflict: The Ethnic Power Relations Dataset Family.

    Get PDF
    ArticleThis article introduces the new Family of Ethnic Power Relations (EPR) data sets, version 2014, which is the latest in a series of data sets on ethnicity that have stimulated civil war research in the past decade. The EPR Family provides data on ethnic groups’ access to state power, their settlement patterns, links to rebel organizations, transborder ethnic kin relations, and intraethnic cleavages. The new 2014 version does not only extend the data set’s temporal coverage from 2009 to 2013, but it also offers several new features, such as a new measure of regional autonomy that is independent of national-level executive power and a new data set component coding intraethnic identities and cleavages. Moreover, for the first time, detailed documentation of the EPR data is provided through the EPR Atlas. This article presents these novelties in detail and compares the EPR Family 2014 to the most relevant alternative data sets on ethnicity.Swiss National Science FoundationSwiss Agency for Development and Cooperation (SDC
    corecore