1,000 research outputs found
Equilibrium properties of highly asymmetric star-polymer mixtures
We employ effective interaction potentials to study the equilibrium structure
and phase behavior of highly asymmetric mixtures of star polymers. We consider
in particular the influence of the addition of a component with a small number
of arms and a small size on a concentrated solution of large stars with a high
functionality. By employing liquid integral equation theories we examine the
evolution of the correlation functions of the big stars upon addition of the
small ones, finding a loss of structure that can be attributed to a weakening
of the repulsions between the large stars due to the presence of the small
ones. We analyze this phenomenon be means of a generalized depletion mechanism
which is supported by computer simulations. By applying thermodynamic
perturbation theory we draw the phase diagram of the asymmetric mixture,
finding that the addition of small stars melts the crystal formed by the big
ones. A systematic comparison between the two- and effective one-component
descriptions of the mixture that corroborates the reliability of the
generalized depletion picture is also carried out.Comment: 26 pages, 9 figures, submitted to Phys. Rev.
Interplay of Dirac nodes and Volkov-Pankratov surface states in compressively strained HgTe
Preceded by the discovery of topological insulators, Dirac and Weyl
semimetals have become a pivotal direction of research in contemporary
condensed matter physics. While easily accessible from a theoretical viewpoint,
these topological semimetals pose a serious challenge in terms of experimental
synthesis and analysis to allow for their unambiguous identification. In this
work, we report on detailed transport experiments on compressively strained
HgTe. Due to the superior sample quality in comparison to other topological
semimetallic materials, this enables us to resolve the interplay of topological
surface states and semimetallic bulk states to an unprecedented degree of
precision and complexity. As our gate design allows us to precisely tune the
Fermi level at the Weyl and Dirac points, we identify a magnetotransport regime
dominated by Weyl/Dirac bulk state conduction for small carrier densities and
by topological surface state conduction for larger carrier densities. As such,
similar to topological insulators, HgTe provides the archetypical reference for
the experimental investigation of topological semimetals.Comment: 8 pages, 7 figures, accepted in PRX, added kp calculation and
supplementar
ARE MUSCLE FORCES RELEVANT IN THE AGE RELATED RISE OF INJURIES IN ADOLESCENT SOCCER PLAYERS?
The purpose of this study was the comparison of the kinematics and kinetics in soccer inside passes between three age groups (U12, U16, U23). Using 3D movement analysis and inverse dynamics, hip joint kinematics and adductor muscle forces were calculated. SPM analysis showed significant differences in adduction angle and velocity and in muscle forces of adductor longus and gracilis. Comparison of the muscle forces shows a rapid increase in muscle forces from the youngest children to the adolescents while the difference between the adolescents and adults is only minor. It seems reasonable, that the fast development of muscle forces in adolescents compared to the slower development of the tendons is a factor in the sudden rise in injury incidence at the beginning of puberty. Therefore, adolescent players should be trained with caution to avoid early injuries
Counterpropagating topological and quantum Hall edge channels
The survival of the quantum spin Hall edge channels in presence of an
external magnetic field has been a subject of experimental and theoretical
research. The inversion of Landau levels that accommodates the quantum spin
Hall effect is destroyed at a critical magnetic field, and a trivial insulating
gap appears in the spectrum for stronger fields. In this work, we report the
absence of this transport gap in disordered two dimensional topological
insulators in perpendicular magnetic fields of up to 16 T. Instead, we observe
that a topological edge channel (from band inversion) coexists with a
counterpropagating quantum Hall edge channel for magnetic fields at which the
transition to the insulating regime is expected. For larger fields, we observe
only the quantum Hall edge channel with transverse resistance close to .
By tuning the disorder using different fabrication processes, we find evidence
that this unexpected plateau originates from extended quantum Hall edge
channels along a continuous network of charge puddles at the edges of the
device.Comment: 8+3 pages, 5+2 figure
Prognostic Factors Affecting Outcome after Allogeneic Transplantation for Hematological Malignancies from Unrelated Donors: Results from a Randomized Trial
Several prognostic factors for the outcome after allogeneic hematopoietic stem-cell transplant (HSCT) from matched unrelated donors have been postulated from registry data; however, data from randomized trials are lacking. We present analyses on the effects of patient-related, donor-related, and treatment-related prognostic factors on acute GVHD (aGVHD), chronic GVHD (cGVHD), relapse, nonrelapse mortality (NRM), disease-free survival (DFS), and overall survival (OS) in a randomized, multicenter, open-label, phase III trial comparing standard graft-versus-host-disease (GVHD) prophylaxis with and without pretransplantation ATG-Fresenius (ATG-F) in 201 adult patients receiving myeloablative conditioning before HSCT from HLA-A, HLA-B antigen, HLA-DRB1, HLA-DQB1 allele matched unrelated donors. High-resolution testing (allele) of HLA-A, HLA-B, and HLA-C were obtained after study closure, and the impact of an HLA 10/10 4-digit mismatch on outcome and on the treatment effect of ATG-F versus control investigated. Advanced disease was a negative factor for relapse, DFS, and OS. Donor age ≥40 adversely affected the risk of aGVHD III-IV, extensive cGVHD, and OS. Younger donors are to be preferred in unrelated donor transplantation. Advanced disease patients need special precautions to improve outcome. The degree of mismatch had no major influence on the positive effect of ATG-F on the reduction of aGVHD and cGVHD
Finding one's way in proteomics: a protein species nomenclature
Our knowledge of proteins has greatly improved in recent years, driven by new technologies in the fields of molecular biology and proteome research. It has become clear that from a single gene not only one single gene product but many different ones - termed protein species - are generated, all of which may be associated with different functions. Nonetheless, an unambiguous nomenclature for describing individual protein species is still lacking. With the present paper we therefore propose a systematic nomenclature for the comprehensive description of protein species. The protein species nomenclature is flexible and adaptable to every level of knowledge and of experimental data in accordance with the exact chemical composition of individual protein species. As a minimum description the entry name (gene name + species according to the UniProt knowledgebase) can be used, if no analytical data about the target protein species are available
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