69 research outputs found
Some properties of the newly observed X(1835) state at BES
Recently the BES collaboration has announced observation of a resonant state
in the spectrum in
decay. Fitting the data with a state, the mass is determined to be
1833.7 MeV with statistic significance. This state is consistent
with the one extracted from previously reported threshold
enhancement data in . We study the properties of
this state using QCD anomaly and QCD sum rules assuming X(1835) to be a
pseudoscalar and show that it is consistent with data. We find that this state
has a sizeable matrix element leading to branching ratios
of and for
and for , respectively.
Combining the calculated branching ratio of and data on
threshold enhancement in , we determine the
coupling for interaction. We finally study branching ratios of
other decay modes. We find that can provide useful
tests for the mechanism proposed.Comment: 13 pages, 3 figures. The final version to appear at EPJ
Microtubule Acetylation Is Required for Mechanosensation in Drosophila
At the cellular level, α-tubulin acetylation alters the structure of microtubules to render them mechanically resistant to compressive forces. How this biochemical property of microtubule acetylation relates to mechanosensation remains unknown, although prior studies have shown that microtubule acetylation influences touch perception. Here, we identify the major Drosophila α-tubulin acetylase (dTAT) and show that it plays key roles in several forms of mechanosensation. dTAT is highly expressed in the larval peripheral nervous system (PNS), but it is largely dispensable for neuronal morphogenesis. Mutation of the acetylase gene or the K40 acetylation site in α-tubulin impairs mechanical sensitivity in sensory neurons and behavioral responses to gentle touch, harsh touch, gravity, and vibration stimuli, but not noxious thermal stimulus. Finally, we show that dTAT is required for mechanically induced activation of NOMPC, a microtubule-associated transient receptor potential channel, and functions to maintain integrity of the microtubule cytoskeleton in response to mechanical stimulation. Yan et al. identify the major microtubule acetylase in Drosophila and show that the enzyme and microtubule acetylation broadly control mechanosensation, but not other sensory modalities. Acetylation is required for mechanosensation by the TRP channel NOMPC, and possibly other channels, by virtue of its effects on microtubule mechanical stability and/or dynamics
HighP–TNano-Mechanics of Polycrystalline Nickel
We have conducted highP–Tsynchrotron X-ray and time-of-flight neutron diffraction experiments as well as indentation measurements to study equation of state, constitutive properties, and hardness of nanocrystalline and bulk nickel. Our lattice volume–pressure data present a clear evidence of elastic softening in nanocrystalline Ni as compared with the bulk nickel. We show that the enhanced overall compressibility of nanocrystalline Ni is a consequence of the higher compressibility of the surface shell of Ni nanocrystals, which supports the results of molecular dynamics simulation and a generalized model of a nanocrystal with expanded surface layer. The analytical methods we developed based on the peak-profile of diffraction data allow us to identify “micro/local” yield due to high stress concentration at the grain-to-grain contacts and “macro/bulk” yield due to deviatoric stress over the entire sample. The graphic approach of our strain/stress analyses can also reveal the corresponding yield strength, grain crushing/growth, work hardening/softening, and thermal relaxation under highP–Tconditions, as well as the intrinsic residual/surface strains in the polycrystalline bulks. From micro-indentation measurements, we found that a low-temperature annealing (T < 0.4 Tm) hardens nanocrystalline Ni, leading to an inverse Hall–Petch relationship. We explain this abnormal Hall–Petch effect in terms of impurity segregation to the grain boundaries of the nanocrystalline Ni
A new method for automatically identifying the shaft orbit moving direction of hydroelectric generating set
Graphene sheets as anode materials for Li-ion batteries: Preparation, structure, electrochemical properties and mechanism for lithium storage
10.1039/c2ra20549aRSC Advances2176792-679
THE ROLE OF SEX HORMONE-BINDING GLOBULIN (SHBG) IN THE ANDROGEN RESPONSE OF HUMAN PROSTATE CANCER CELLS
- …