662 research outputs found
On-chip black hole: Hawking radiation and curved spacetime in a superconducting quantum circuit with tunable couplers
Hawking radiation is one of quantum features of a black hole, which can be
understood as a quantum tunneling across the event horizon of the black hole,
but it is quite difficult to directly observe the Hawking radiation of an
astrophysical black hole. Remarkable experiments of analogue black holes on
various platforms have been performed. However, Hawking radiation and its
quantum nature such as entanglement have not been well tested due to the
experimental challenges in accurately constructing curved spacetime and
precisely measuring the thermal spectrum. Based on the recent architecture
breakthrough of tunable couplers for superconducting processor, we realize
experimentally an analogue black hole using our new developed chip with a chain
of 10 superconducting transmon qubits with interactions mediated by 9
transmon-type tunable couplers. By developing efficient techniques to engineer
the couplings between qubits via tuning couplers, we realize both the flat and
curved spacetime backgrounds. The quantum walks of quasi-particle in the curved
spacetime reflect the gravitational effect around the black hole, resulting in
the behavior of Hawking radiation. By virtue of the state tomography
measurement of all 7 qubits outside the analogue event horizon, we show that
Hawking radiation can be verified. In addition, an entangled pair is prepared
inside the horizon and the dynamics of entanglement in the curved spacetime is
directly measured. Our results would stimulate more interests to explore
information paradox, entropy and other related features of black holes using
programmable superconducting processor with tunable couplers.Comment: modified manuscripts, 7 pages, 4 figures (main text) + 12 pages
(supplementary information
miR-27b Suppresses Endothelial Cell Proliferation and Migration by Targeting Smad7 in Kawasaki Disease
Background/Aims: Increasing evidence indicates that microRNAs (miRNAs) play important roles in Kawasaki disease (KD). Our previous study demonstrated that hsa-miR-27b-3p (miR-27b) was up-regulated in KD serum. However, the specific role of miR-27b in KD remains unclear. We aimed to investigate that miR-27b could be a biomarker and therapeutic target for KD treatment. As well, the specific mechanism of miR-27b effecting endothelial cell functions was studied. Methods: The expression of miR-27b and Smad7 was measured by qRT-PCR. Gain-of-function strategy was used to observe the effect of miR-27b on human umbilical vein endothelial cells (HUVECs) proliferation and migration. Bioinformatics analyses were applied to predict miR-27b targets and then we verified Smad7 by a luciferase reporter assay. Western blot was performed to detect the protein expression of Smad7, PCNA, MMP9, MMP12 and TGF-β-related genes. Results: We confirmed that miR-27b was shown to be dramatically up-regulated in KD serum and KD serum-treated HUVECs and that elevated expression of miR-27b suppressed the proliferation and migration of HUVECs. Furthermore, our results verified that miR-27b mediated cell functions by affecting the TGF-β via targeting Smad7 in HUVECs. Conclusion: These results suggested that up-regulated miR-27b had a protective role in HUVECs proliferation and migration via targeting Smad7 and affecting TGF-β pathway. Therefore, miR-27b represented a potential biomarker for KD and may serve as a promising therapeutic target for KD treatment
ATOMS : ALMA Three-millimeter Observations of Massive Star-forming regions - XI. From inflow to infall in hub-filament systems
We investigate the presence of hub-filament systems in a large sample of 146 active proto-clusters, using (HCO+)-C-13 J = 1-0 molecular line data obtained from the ATOMS survey. We find that filaments are ubiquitous in proto-clusters, and hub-filament systems are very common from dense core scales (similar to 0.1 pc) to clump/cloud scales (similar to 1-10 pc). The proportion of proto-clusters containing hub-filament systems decreases with increasing dust temperature (T-d) and luminosity-to-mass ratios (L/M) of clumps, indicating that stellar feedback from H ii regions gradually destroys the hub-filament systems as proto-clusters evolve. Clear velocity gradients are seen along the longest filaments with a mean velocity gradient of 8.71 km s(-1) pc(-1) and a median velocity gradient of 5.54 km s(-1) pc(-1). We find that velocity gradients are small for filament lengths larger than similar to 1 pc, probably hinting at the existence of inertial inflows, although we cannot determine whether the latter are driven by large-scale turbulence or large-scale gravitational contraction. In contrast, velocity gradients below similar to 1 pc dramatically increase as filament lengths decrease, indicating that the gravity of the hubs or cores starts to dominate gas infall at small scales. We suggest that self-similar hub-filament systems and filamentary accretion at all scales may play a key role in high-mass star formation.Peer reviewe
A longitudinal resource for population neuroscience of school-age children and adolescents in China
During the past decade, cognitive neuroscience has been calling for population diversity to address the challenge of validity and generalizability, ushering in a new era of population neuroscience. The developing Chinese Color Nest Project (devCCNP, 2013–2022), the first ten-year stage of the lifespan CCNP (2013–2032), is a two-stages project focusing on brain-mind development. The project aims to create and share a large-scale, longitudinal and multimodal dataset of typically developing children and adolescents (ages 6.0–17.9 at enrolment) in the Chinese population. The devCCNP houses not only phenotypes measured by demographic, biophysical, psychological and behavioural, cognitive, affective, and ocular-tracking assessments but also neurotypes measured with magnetic resonance imaging (MRI) of brain morphometry, resting-state function, naturalistic viewing function and diffusion structure. This Data Descriptor introduces the first data release of devCCNP including a total of 864 visits from 479 participants. Herein, we provided details of the experimental design, sampling strategies, and technical validation of the devCCNP resource. We demonstrate and discuss the potential of a multicohort longitudinal design to depict normative brain growth curves from the perspective of developmental population neuroscience. The devCCNP resource is shared as part of the “Chinese Data-sharing Warehouse for In-vivo Imaging Brain” in the Chinese Color Nest Project (CCNP) – Lifespan Brain-Mind Development Data Community (https://ccnp.scidb.cn) at the Science Data Bank
Reduced conditioned fear response in mice that lack Dlx1 and show subtype-specific loss of interneurons
The inhibitory GABAergic system has been implicated in multiple neuropsychiatric diseases such as schizophrenia and autism. The Dlx homeobox transcription factor family is essential for development and function of GABAergic interneurons. Mice lacking the Dlx1 gene have postnatal subtype-specific loss of interneurons and reduced IPSCs in their cortex and hippocampus. To ascertain consequences of these changes in the GABAergic system, we performed a battery of behavioral assays on the Dlx1 mutant mice, including zero maze, open field, locomotor activity, food intake, rotarod, tail suspension, fear conditioning assays (context and trace), prepulse inhibition, and working memory related tasks (spontaneous alteration task and spatial working memory task). Dlx1 mutant mice displayed elevated activity levels in open field, locomotor activity, and tail suspension tests. These mice also showed deficits in contextual and trace fear conditioning, and possibly in prepulse inhibition. Their learning deficits were not global, as the mutant mice did not differ from the wild-type controls in tests of working memory. Our findings demonstrate a critical role for the Dlx1 gene, and likely the subclasses of interneurons that are affected by the lack of this gene, in behavioral inhibition and associative fear learning. These observations support the involvement of particular components of the GABAergic system in specific behavioral phenotypes related to complex neuropsychiatric diseases
Vitamin D and cause-specific vascular disease and mortality:a Mendelian randomisation study involving 99,012 Chinese and 106,911 European adults
Study of the doubly Cabibbo-suppressed decays and
Based on 7.33 fb of collision data collected at
center-of-mass energies between 4.128 and 4.226 GeV with the BESIII detector,
the experimental studies of the doubly Cabibbo-suppressed decays and are reported. We determine the
absolute branching fraction of to be
() . No
significant signal of is observed and the upper
limit on its decay branching fraction at 90\% confidence level is set to be
.Comment: 10 pages, 4 figures, 4 table
Updated measurements of the M1 transition with
Based on a data sample of events
collected with the BESIII detector at the BEPCII collider, the M1 transition
with is
studied, where is or
. The mass and width of the are
measured to be MeV/
and MeV, respectively. The
product branching fraction is determined to be . Using , we obtain the branching fraction of the
radiative transition to be , where the third uncertainty is due to the quoted
Search for hidden-charm tetraquark with strangeness in
We report a search for a heavier partner of the recently observed
state, denoted as , in the process , based on collision data
collected at the center-of-mass energies of , 4.682 and 4.699
GeV with the BESIII detector. The is of interest as it is
expected to be a candidate for a hidden-charm and open-strange tetraquark. A
partial-reconstruction technique is used to isolate recoil-mass spectra,
which are probed for a potential contribution from (). We find an excess of () candidates with a significance of , after
considering systematic uncertainties, at a mass of . As the data
set is limited in size, the upper limits are evaluated at the 90% confidence
level on the product of the Born cross section and the branching fraction of
, at the three energy points, under different assumptions
of the mass from 4.120 to 4.140 MeV and of the width from
10 to 50 MeV. Under various mass and width assumptions, the upper limits of
are found to lie in the range of ,
and pb at , 4.682 and 4.699 GeV,
respectively. The larger data samples that will be collected in the coming
years will allow a clearer picture to emerge concerning the existence and
nature of the state.Comment: 17 pages, 7 figure
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