178 research outputs found
Designing organometallic compounds for catalysis and therapy
Bioorganometallic chemistry is a rapidly developing area of research. In recent years organometallic compounds have provided a rich platform for the design of effective catalysts, e.g. for olefin metathesis and transfer hydrogenation. Electronic and steric effects are used to control both the thermodynamics and kinetics of ligand substitution and redox reactions of metal ions, especially Ru II. Can similar features be incorporated into the design of targeted organometallic drugs? Such complexes offer potential for novel mechanisms of drug action through incorporation of outer-sphere recognition of targets and controlled activation features based on ligand substitution as well as metal- and ligand-based redox processes. We focus here on η 6-arene, η 5-cyclopentadienyl sandwich and half-sandwich complexes of Fe II, Ru II, Os II and Ir III with promising activity towards cancer, malaria, and other conditions. © 2012 The Royal Society of Chemistry
Heptacarbonyl-1κ3 C,2κ4 C-(4-phenylpyridine-1κN)di-μ-phenyltellurido-1:2κ4 Te:Te-dirhenium(I)
In the title complex, [Re2(C6H5Te)2(C11H9N)(CO)7], two Re atoms are coordinated in slightly distorted octahedral coordination environments and are bridged by two Te atoms, which are coordinated in trigonal-pyramidal environments. The torsion angle for the Te—Re—Te—Re sequence of atoms is 17.06 (3)°. The crystal structure is stabilized by weak C—H⋯O and C—H⋯π interactions. In addition, there are Te⋯Te distances [4.0392 (12) Å] and O⋯O distances [2.902 (19) Å] which are shorter than the sum of the van der Waals radii for these atoms. A short intermolecular lone pair⋯π distance [C O⋯Cg = 3.31 (2) Å] is also observed
The High-Acceptance Dielectron Spectrometer HADES
HADES is a versatile magnetic spectrometer aimed at studying dielectron
production in pion, proton and heavy-ion induced collisions. Its main features
include a ring imaging gas Cherenkov detector for electron-hadron
discrimination, a tracking system consisting of a set of 6 superconducting
coils producing a toroidal field and drift chambers and a multiplicity and
electron trigger array for additional electron-hadron discrimination and event
characterization. A two-stage trigger system enhances events containing
electrons. The physics program is focused on the investigation of hadron
properties in nuclei and in the hot and dense hadronic matter. The detector
system is characterized by an 85% azimuthal coverage over a polar angle
interval from 18 to 85 degree, a single electron efficiency of 50% and a vector
meson mass resolution of 2.5%. Identification of pions, kaons and protons is
achieved combining time-of-flight and energy loss measurements over a large
momentum range. This paper describes the main features and the performance of
the detector system
Scale-free static and dynamical correlations in melts of monodisperse and Flory-distributed homopolymers: A review of recent bond-fluctuation model studies
It has been assumed until very recently that all long-range correlations are
screened in three-dimensional melts of linear homopolymers on distances beyond
the correlation length characterizing the decay of the density
fluctuations. Summarizing simulation results obtained by means of a variant of
the bond-fluctuation model with finite monomer excluded volume interactions and
topology violating local and global Monte Carlo moves, we show that due to an
interplay of the chain connectivity and the incompressibility constraint, both
static and dynamical correlations arise on distances . These
correlations are scale-free and, surprisingly, do not depend explicitly on the
compressibility of the solution. Both monodisperse and (essentially)
Flory-distributed equilibrium polymers are considered.Comment: 60 pages, 49 figure
Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets
This document is the Technical Design Report covering the two large
spectrometer magnets of the PANDA detector set-up. It shows the conceptual
design of the magnets and their anticipated performance. It precedes the tender
and procurement of the magnets and, hence, is subject to possible modifications
arising during this process.Comment: 10 pages, 14MB, accepted by FAIR STI in May 2009, editors: Inti
Lehmann (chair), Andrea Bersani, Yuri Lobanov, Jost Luehning, Jerzy Smyrski,
Technical Coordiantor: Lars Schmitt, Bernd Lewandowski (deputy),
Spokespersons: Ulrich Wiedner, Paola Gianotti (deputy
Observations on the inconsistency of dermatome maps and its effect on knowledge and confidence in clinical students.
Dermatomes are an important component of medical curricula and clinical practice. In addition to the intrinsic complexity of dermatome maps, their discrepancies in the literature make their learning among students even more difficult. These discrepancies are particularly evident in the lower deltoid ("regimental badge" area) and upper back. The aims of our study were firstly to identify and compare published versions of the dermatome map focusing on depictions of the "regimental badge" area and upper back, secondly to assess the perceived confidence and knowledge of dermatomes among medical students, and finally to create and introduce a simplified dermatome map. For the first part of the study, depictions of dermatome maps that included the "regimental badge" area and upper back in webpages and books were compared. For the second part, a dermatome exercise was given to 177 medical students who were asked to draw and label the dermatomes on blank figures. A total of 45 sources depicting dermatomes of the "regimental badge" area and upper back were included in the study and showed significant discrepancies in both areas. In the dermatome exercise, the mean perceived confidence was 3.64 ± 1.58 (scale 1-10). Based on our pre-set assessment criteria, upper limb, lower limb, nipple, umbilicus, and perineum dermatomes were labeled correctly by 57.1%, 43.5%, 52.6%, 60%, and 75.7% students, respectively. In light of our results, we propose a map of autonomous regions of clinically relevant dermatomes that can be used instead of whole dermatome maps for teaching purposes. Clin. Anat. 31:293-300, 2018. © 2017 Wiley Periodicals, Inc
Physics Performance Report for PANDA: Strong Interaction Studies with Antiprotons
To study fundamental questions of hadron and nuclear physics in interactions
of antiprotons with nucleons and nuclei, the universal PANDA detector will be
built. Gluonic excitations, the physics of strange and charm quarks and nucleon
structure studies will be performed with unprecedented accuracy thereby
allowing high-precision tests of the strong interaction. The proposed PANDA
detector is a state-of-the art internal target detector at the HESR at FAIR
allowing the detection and identification of neutral and charged particles
generated within the relevant angular and energy range. This report presents a
summary of the physics accessible at PANDA and what performance can be
expected.Comment: 216 page
Technical Design Report for the: PANDA Micro Vertex Detector
This document illustrates the technical layout and the expected performance
of the Micro Vertex Detector (MVD) of the PANDA experiment. The MVD will detect
charged particles as close as possible to the interaction zone. Design criteria
and the optimisation process as well as the technical solutions chosen are
discussed and the results of this process are subjected to extensive Monte
Carlo physics studies. The route towards realisation of the detector is
outlined.Comment: 189 pages, 225 figures, 41 table
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