3,194 research outputs found
The production of dijet in heavy-ion collisions at the LHC
We report our recent theoretical calculations for dijet production
in high-energy nuclear collisions. The NLO+parton shower (PS) event generator
SHERPA has been employed to provide the pp baseline of dijet
production. A framework which combines Langevin transport equation to describe
the evolution of heavy quarks and the higher-twist scheme to consider the
inelastic energy loss of both light and heavy partons has been implemented.
Within this framework, we present the theoretical result of transverse momentum
imbalance both for inclusive dijet and dijet in
Pb+Pb collision at 5.02 TeV. The energy loss of b jet would shift to
smaller value relative to p+p reference which is consistent with the CMS data.
In addition, we show the medium modification for angular correlation of
dijet in A+A collision at ~TeV. We observe a
stronger suppression in small region where
the gluon splitting processes dominate relative to large region.
The difference leads to a modest suppression on near side ()
and enhancement on away side ().Comment: 4 pages, 4 figures, Parallel talk presented at Hard Probes 201
(E)-N′-(5-Chloro-2-hydroxybenzylidene)-3,5-dihydroxybenzohydrazide monohydrate
In the title compound, C14H11ClN2O4·H2O, the dihedral angle between the two benzene rings is 8.5 (2)° and an intramolecular O—H⋯N hydrogen bond is observed in the Schiff base molecule. In the crystal structure, the water molecule accepts an N—H⋯O hydrogen bond and makes O—H⋯O hydrogen bonds to two further Schiff base molecules. Further intermolecular O—H⋯O hydrogen bonds lead to the formation of layers parallel to the bc plane
Activity-dependent neurorehabilitation beyond physical trainings: "mental exercise" through mirror neuron activation
The activity dependent brain repair mechanism has been widely adopted in many types of neurorehabilitation. The activity leads to target specific and non-specific beneficial effects in different brain regions, such as the releasing of neurotrophic factors, modulation of the cytokines and generation of new neurons in adult hood. However physical exercise program clinically are limited to some of the patients with preserved motor functions; while many patients suffered from paralysis cannot make such efforts. Here the authors proposed the employment of mirror neurons system in promoting brain rehabilitation by "observation based stimulation". Mirror neuron system has been considered as an important basis for action understanding and learning by mimicking others. During the action observation, mirror neuron system mediated the direct activation of the same group of motor neurons that are responsible for the observed action. The effect is clear, direct, specific and evolutionarily conserved. Moreover, recent evidences hinted for the beneficial effects on stroke patients after mirror neuron system activation therapy. Finally some music-relevant therapies were proposed to be related with mirror neuron system
Electrically controlled long-distance spin transport through an antiferromagnetic insulator
Spintronics uses spins, the intrinsic angular momentum of electrons, as an
alternative for the electron charge. Its long-term goal is in the development
of beyond-Moore low dissipation technology devices. Recent progress
demonstrated the long-distance transport of spin signals across ferromagnetic
insulators. Antiferromagnetically ordered materials are however the most common
class of magnetic materials with several crucial advantages over ferromagnetic
systems. In contrast to the latter, antiferromagnets exhibit no net magnetic
moment, which renders them stable and impervious to external fields. In
addition, they can be operated at THz frequencies. While fundamentally their
properties bode well for spin transport, previous indirect observations
indicate that spin transmission through antiferromagnets is limited to short
distances of a few nanometers. Here we demonstrate the long-distance, over tens
of micrometers, propagation of spin currents through hematite (\alpha-Fe2O3),
the most common antiferromagnetic iron oxide, exploiting the spin Hall effect
for spin injection. We control the spin current flow by the interfacial
spin-bias and by tuning the antiferromagnetic resonance frequency with an
external magnetic field. This simple antiferromagnetic insulator is shown to
convey spin information parallel to the compensated moment (N\'eel order) over
distances exceeding tens of micrometers. This newly-discovered mechanism
transports spin as efficiently as the net magnetic moments in the best-suited
complex ferromagnets. Our results pave the way to ultra-fast, low-power
antiferromagnet-insulator-based spin-logic devices that operate at room
temperature and in the absence of magnetic fields
Molecular Valves for Controlling Gas Phase Transport Made from Discrete Angstrom-Sized Pores in Graphene
An ability to precisely regulate the quantity and location of molecular flux
is of value in applications such as nanoscale 3D printing, catalysis, and
sensor design. Barrier materials containing pores with molecular dimensions
have previously been used to manipulate molecular compositions in the gas
phase, but have so far been unable to offer controlled gas transport through
individual pores. Here, we show that gas flux through discrete angstrom-sized
pores in monolayer graphene can be detected and then controlled using
nanometer-sized gold clusters, which are formed on the surface of the graphene
and can migrate and partially block a pore. In samples without gold clusters,
we observe stochastic switching of the magnitude of the gas permeance, which we
attribute to molecular rearrangements of the pore. Our molecular valves could
be used, for example, to develop unique approaches to molecular synthesis that
are based on the controllable switching of a molecular gas flux, reminiscent of
ion channels in biological cell membranes and solid state nanopores.Comment: to appear in Nature Nanotechnolog
β Subunit M2–M3 Loop Conformational Changes Are Uncoupled from α1 β Glycine Receptor Channel Gating: Implications for Human Hereditary Hyperekplexia
Hereditary hyperekplexia, or startle disease, is a neuromotor disorder caused mainly by mutations that either prevent the surface expression of, or modify the function of, the human heteromeric α1 β glycine receptor (GlyR) chloride channel. There is as yet no explanation as to why hyperekplexia mutations that modify channel function are almost exclusively located in the α1 to the exclusion of β subunit. The majority of these mutations are identified in the M2–M3 loop of the α1 subunit. Here we demonstrate that α1 β GlyR channel function is less sensitive to hyperekplexia-mimicking mutations introduced into the M2–M3 loop of the β than into the α1 subunit. This suggests that the M2–M3 loop of the α subunit dominates the β subunit in gating the α1 β GlyR channel. A further attempt to determine the possible mechanism underlying this phenomenon by using the voltage-clamp fluorometry technique revealed that agonist-induced conformational changes in the β subunit M2–M3 loop were uncoupled from α1 β GlyR channel gating. This is in contrast to the α subunit, where the M2–M3 loop conformational changes were shown to be directly coupled to α1 β GlyR channel gating. Finally, based on analysis of α1 β chimeric receptors, we demonstrate that the structural components responsible for this are distributed throughout the β subunit, implying that the β subunit has evolved without the functional constraint of a normal gating pathway within it. Our study provides a possible explanation of why hereditary hyperekplexia-causing mutations that modify α1 β GlyR channel function are almost exclusively located in the α1 to the exclusion of the β subunit
Leaf senescence and photosynthesis in foxtail millet [Setaria italica (L.) P. Beauv] varieties exposed to drought conditions
Abstract In this paper, we studied the changes of net photosynthetic rates (P n ), the contents of chlorophyll, soluble protein, malondialdehyde (MDA), superoxide radical (O 2 -· ), and hydrogen peroxide (H 2 O 2 ), and the activities of superoxide dismutase (SOD; EC1.15.1.1) and catalase (CAT; EC 1.11.1.6) in the leaves of two foxtail millet varieties (05-61 and Jingu3) under drought stress from 14 days after anthesis to maturity. P N , the contents of chlorophyll and soluble protein and the activities of SOD and CAT increased and then declined as the plants aged, whereas the accumulation of MDA, O 2 -· and H 2 O 2 gradually increased with senescence. Although the leaves of two varieties generally shared a similar pattern of senescence, their rates of aging differed. The activities of SOD and CAT in leaves of 05-61 declined more quickly than Jingu3, particularly in the late stages of grain filling. Taken together, the results implicated that the alleviation of leaf senescence played an important role in promoting grain filling and enhancing the yield and quality of 05-61 in the rain-fed agriculture area
In support of descriptive studies; relevance to translational research
The contemporary scientific establishment equates hypothesis testing to good science. This stance bypasses the preliminary need to identify a worthwhile hypothesis through rigorous observation of natural processes. If alleviation of human suffering is claimed as the goal of a scientific undertaking, it would be unfair to test a hypothesis whose relevance to human disease has not been satisfactorily proven. Here, we argue that descriptive investigations based on direct human observation should be highly valued and regarded essential for the selection of worthwhile hypotheses while the pursuit of costly scientific investigations without such evidence is a desecration of the cause upon which biomedical research is grounded
- …