1,798 research outputs found
Hidden-bottom molecular states from interaction
In this work, we study possible hidden-bottom molecular pentaquarks
from coupled-channel interaction in
the quasipotential Bethe-Salpeter equation approach. In isodoublet sector with
, with the same reasonable parameters the interaction produces seven
molecular states, a state near threshold with spin parity
, a state near threshold with , two states near
threshold with and , and three states near
threshold with , , and . The results
suggest that three states near threshold and two states near
threshold are very close, respectively, which may be difficult
to distinguish in experiment without partial wave analysis. Compared with the
hidden-charm pentaquark, the states are relatively narrow with widths at
an order of magnitude of 1 MeV or smaller. The importance of each channel
considered is also discussed, and it is found that the channel
provides important contribution for the widths of those states. In isoquartet
sector with , cutoff should be considerably enlarged to achieve bound
states from the interaction, which makes the existence of such states
unreliable. The results in the current work are helpful for searching for
hidden-bottom molecular pentaquarks in future experiments, such as the COMPASS,
J-PARC, and the Electron Ion Collider in China (EicC).Comment: 8 pages, 3 figure
Possible molecular dibaryons with quarks and their baryon-antibaryon partners
In this work, we systematically investigate the charmed-strange dibaryon
systems with quarks and their baryon-antibaryon partners from the
interactions , ,
, and and
their baryon-antibaryon partners from interactions
, ,
, and
. The potential kernels are constructed with the
help of effective Lagrangians under SU(3), heavy quark, and chiral symmetries
to describe these interactions. To search for possible molecular states, the
kernels are inserted into the quasipotential Bethe-Salpeter equation, which is
solved to find poles from scattering amplitude. The results suggest that 36 and
24 bound states can be found in the baryon-baryon and baryon-antibaryon
interactions, respectively. However, much large values of parameter
are required to produce the bound states from the baryon-antibaryon
interactions, which questions the existence of these bound states. Possible
coupled-channel effect are considered in the current work to estimate the
couplings of the molecular states to the channels considered.Comment: 13 pages, 5 figures. arXiv admin note: text overlap with
arXiv:2208.1196
Extraordinary focusing of sound above a soda can array without time reversal
Recently, Lemoult et al. [Phys. Rev. Lett. 107, 064301 (2011)] used time
reversal to focus sound above an array of soda cans into a spot much smaller
than the acoustic wavelength in air. In this study, we show that equally sharp
focusing can be achieved without time reversal, by arranging transducers around
a nearly circular array of soda cans. The size of the focal spot at the center
of the array is made progressively smaller as the frequency approaches the
Helmholtz resonance frequency of a can from below, and, near the resonance,
becomes smaller than the size of a single can. We show that the locally
resonant metamaterial formed by soda cans supports a guided wave at frequencies
below the Helmholtz resonance frequency. The small focal spot results from a
small wavelength of this guided wave near the resonance in combination with a
near field effect making the acoustic field concentrate at the opening of a
can. The focusing is achieved with propagating rather than evanescent waves. No
sub-diffraction-limited focusing is observed if the diffraction limit is
defined with respect to the wavelength of the guided mode in the metamaterial
medium rather than the wavelength of the bulk wave in air
Possible molecular states from interactions of charmed baryons
In this work, we perform a systematic study of possible molecular states
composed of two charmed baryons including hidden-charm systems
, , and
, and corresponding double-charm systems
, , and
. With the help of the heavy quark chiral effective
Lagrangians, the interactions are described with , , ,
, , and exchanges. The potential kernels are
constructed, and inserted into the quasipotential Bethe-Salpeter equation. The
bound states from the interactions considered is studied by searching for the
poles of the scattering amplitude. The results suggest that strong attractions
exist in both hidden-charm and double-charm systems considered in the current
work, and bound states can be produced in most of the systems. More experiment
studies about these molecular states are suggested though the nucleon-nucleon
collison at LHC and nucleon-antinucleon collison at .Comment: 7 pages, 5 figure
Effects of STAT3 Gene Silencing and Rapamycin on Apoptosis in Hepatocarcinoma Cells
The PI3K/Akt/mTOR and JAK/STAT3 signaling pathways are important for regulating apoptosis, and are frequently activated in cancers. In this study, we targeted STAT3 and mTOR in human hepatocellular carcinoma Bel-7402 cells and examined the subsequent alterations in cellular apoptosis. The expression of STAT3 was silenced with small interfering RNA (siRNA)-expressing plasmid. The activity of mTOR was inhibited using rapamycin. Following treatment, Annexin V/propidium iodide staining followed by flow cytometry and Hoechst33258 immunofluorescence staining was used to examine cellular apoptosis. JC-1 staining was used to monitor depolarization of mitochondrial membrane (ΔΨm). Furthermore, the expression of activated caspase 3 protein was analyzed by Western blotting. Compared to non-treated or control siRNA-transfected cells, significantly higher levels of apoptosis were detected in siSTAT3-transfected or rapamycin-treated cells (P < 0.05), which was further enhanced in cells targeted for both molecules (P < 0.05). The pro-apoptotic effects were accompanied with concomitant depolarization of mitochondrial membrane and up-regulation of activated caspase 3. Combined treatments using rapamycin and STAT3 gene silencing significantly increases apoptosis in Bel-7402 cells, displaying more dramatic effect than any single treatment. This study provides evidence for targeting multiple molecules in cancer therapy
Introduction to the wheelchair training's influence on the rehabilitation of patients
目的 通过轮椅训练提高患者掌握轮椅的技巧,保证患者乘坐轮椅时的安全,提高患者日常生活能力及社会参与能力。方法 通过轮椅基本技术动作练习、轮椅技巧动作训练、轮椅体育项目训练、社会实践检测。结果 患者轮椅训练前后对照,躯干的控制能力较前好转,ADL能力明显提高,社会参与能力增强。结论 轮椅训练可以使残疾人参与康复体育和社会活动的机会明显增加。Objective: Training to improve patient’s master of wheelchair technology to ensure the safety of patients in wheelchairs things to improve patients' daily living skills and social participation skills. Methods: By practicing basic techniques wheelchair, wheelchair technology movement training, wheelchair sports training, social practice test. Results: Wheelchair patients before and after control technology, the ability to control the trunk before it gets better, ADL ability as well as social participation improved significantly. Conclusion: Wheelchair training increased opportunities for people with disabilities to participate in the rehabilitation of sports and social activities.
Neutron star phase transition as the origin for the fast radio bursts and soft gamma-ray repeaters of SGR J1935+2154
Magnetars are believed as neutron stars (NSs) with strong magnetic fields.
X-ray flares and fast radio bursts (FRBs) have been observed from the magnetar
(soft gamma-ray repeater, SGR J1935+2154). We propose that the phase transition
of the NS can power the FRBs and SGRs.Based on the equation of state provided
by the MIT bag model and the mean field approximation, we solve the
Tolman-Oppenheimer-Volkoff equations to get the NS structure. With spin-down of
the NS, the hadronic shell gradually transfers to the quark shell.The
gravitational potential energy released by one time of the phase transition can
be achieved. The released energy, time interval between two successive phase
transitions, and glitch are all consistent with the observations of the FRBs
and the X-ray flares from SGR J1935+2154. We conclude that the phase transition
of an NS is a plausible mechanism to power the SGRs as well as the repeating
FRBs.Comment: 11 pages, 3 figure
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