867 research outputs found
N17 Modifies mutant Huntingtin nuclear pathogenesis and severity of disease in HD BAC transgenic mice.
The nucleus is a critical subcellular compartment for the pathogenesis of polyglutamine disorders, including Huntington's disease (HD). Recent studies suggest the first 17-amino-acid domain (N17) of mutant huntingtin (mHTT) mediates its nuclear exclusion in cultured cells. Here, we test whether N17 could be a molecular determinant of nuclear mHTT pathogenesis in vivo. BAC transgenic mice expressing mHTT lacking the N17 domain (BACHD-ΔN17) show dramatically accelerated mHTT pathology exclusively in the nucleus, which is associated with HD-like transcriptionopathy. Interestingly, BACHD-ΔN17 mice manifest more overt disease-like phenotypes than the original BACHD mice, including body weight loss, movement deficits, robust striatal neuron loss, and neuroinflammation. Mechanistically, N17 is necessary for nuclear exclusion of small mHTT fragments that are part of nuclear pathology in HD. Together, our study suggests that N17 modifies nuclear pathogenesis and disease severity in HD mice by regulating subcellular localization of known nuclear pathogenic mHTT species
Synergistically enhance confined diffusion by continuum intersecting channels in zeolites
In separation and catalysis applications, adsorption and diffusion are normally considered mutually exclusive. That is, rapid diffusion is generally accompanied by weak adsorption and vice versa. In this work, we analyze the anomalous loading-dependent mechanism of p-xylene diffusion in a newly developed zeolite called SCM-15. The obtained results demonstrate that the unique system of “continuum intersecting channels” (i.e., channels made of fused cavities) plays a key role in the diffusion process for the molecule-selective pathways. At low pressure, the presence of strong adsorption sites and intersections that provide space for molecule rotation facilitates the diffusion of p-xylene along the Z direction. Upon increasing the molecular uptake, the adsorbates move faster along the X direction because of the effect of continuum intersections in reducing the diffusion barriers and thus maintaining the large diffusion coefficient of the diffusing compound. This mechanism synergistically improves the diffusion in zeolites with continuum intersecting channels.This work was supported by the National Natural Science Foundation of China (nos. 22032005, 21902180, 21802164, 21991092, 21991090, 22002174, and 91645112), the Natural Science Foundation of Hubei Province of China (2018CFA009), the Key Research Program of Frontier Sciences (CAS no. QYZDB-SSW-SLH026), Sinopec Corp. (417012-4), and the CAS Interdisciplinary Innovation Team (grant no. JCTD-2018-10). G.S. thanks the MICINN of Spain for funding through projects RTI2018-101784-B-I00, RTI2018-101033-B-I00, and SEV-2016-0683
Thermal resistance effect on anomalous diffusion of molecules under confinement
Diffusion is generally faster at higher temperatures. Here, a counterintuitive behavior is observed in that the movement of long-chain molecules slows as the temperature increases under confinement. This report confirms that this anomalous diffusion is caused by the “thermal resistance effect,” in which the diffusion resistance of linear-chain molecules is equivalent to that with branched-chain configurations at high temperature. It then restrains the molecular transportation in the nanoscale channels, as further confirmed by zero length column experiments. This work enriches our understanding of the anomalous diffusion family and provides fundamental insights into the mechanism inside confined systems.This work is supported by the National NaturalScience Foundation of China (22032005, 21902180, 21802164, 21991092,21991090, 22002174 and 91645112), and the Natural Science Foundation ofHubei Province of China (2018CFA009), the Key Research Program of FrontierSciences, Chinese Academy of Sciences (QYZDB-SSW-SLH026), and SinopecCorp. (417012-4). We are grateful to the Shenzhen Cloud Computing Centerfor their support in computing facilities.Peer reviewe
Precision measurement of the branching fractions of J/psi -> pi+pi-pi0 and psi' -> pi+pi-pi0
We study the decays of the J/psi and psi' mesons to pi+pi-pi0 using data
samples at both resonances collected with the BES III detector in 2009. We
measure the corresponding branching fractions with unprecedented precision and
provide mass spectra and Dalitz plots. The branching fraction for J/psi ->
pi+pi-pi0 is determined to be (2.137 +- 0.004 (stat.) +0.058-0.056 (syst.)
+0.027-0.026 (norm.))*10-2, and the branching fraction for psi' -> pi+pi-pi0 is
measured as (2.14 +- 0.03 (stat.) +0.08-0.07 (syst.) +0.09-0.08 (norm.))*10-4.
The J/psi decay is found to be dominated by an intermediate rho(770) state,
whereas the psi' decay is dominated by di-pion masses around 2.2 GeV/c2,
leading to strikingly different Dalitz distributions.Comment: 15 pages, 2 figure
Study of and
The decays and have been
investigated with a sample of 225.2 million events collected with the
BESIII detector at the BEPCII collider. The branching fractions are
determined to be and . Distributions of the angle
between the proton or anti-neutron and the beam direction are well
described by the form , and we find
for and
for . Our branching-fraction
results suggest a large phase angle between the strong and electromagnetic
amplitudes describing the decay.Comment: 16 pages, 13 figures, the 2nd version, submitted to PR
Measurement of the proton form factor by studying
Using data samples collected with the BESIII detector at the BEPCII collider,
we measure the Born cross section of at 12
center-of-mass energies from 2232.4 to 3671.0 MeV. The corresponding effective
electromagnetic form factor of the proton is deduced under the assumption that
the electric and magnetic form factors are equal . In
addition, the ratio of electric to magnetic form factors, , and
are extracted by fitting the polar angle distribution of the proton
for the data samples with larger statistics, namely at 2232.4 and
2400.0 MeV and a combined sample at = 3050.0, 3060.0 and 3080.0 MeV,
respectively. The measured cross sections are in agreement with recent results
from BaBar, improving the overall uncertainty by about 30\%. The
ratios are close to unity and consistent with BaBar results in
the same region, which indicates the data are consistent with the
assumption that within uncertainties.Comment: 13 pages, 24 figure
Observation of a charged charmoniumlike structure in at GeV
We study the process at a
center-of-mass energy of 4.26GeV using a 827pb data sample obtained with
the BESIII detector at the Beijing Electron Positron Collider. Based on a
partial reconstruction technique, the Born cross section is measured to be
pb. We observe a structure near the
threshold in the recoil mass spectrum, which we denote as the
. The measured mass and width of the structure are
MeV/c and MeV, respectively. Its
production ratio is determined to be . The first uncertainties
are statistical and the second are systematic.Comment: 7 pages, 4 figures, 1 table; version accepted to be published in PR
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