79 research outputs found
The asymptotic stability of solitons in the focusing Hirota equation on the line
In this paper, the -steepest descent method and B\"acklund
transformation are used to study the asymptotic stability of solitons to the
Cauchy problem of focusing Hirota equation. The solution of the RH problem is
further decomposed into pure radiation solution and solitons solution obtained
by using -techniques and B\"acklund transformation
respectively. As a directly consequence, the asymptotic stability of solitons
for the Hirota equation is obtained.Comment: 43 pages. arXiv admin note: text overlap with arXiv:1302.1215 by
other author
Biomechanical analysis of the Maxillary Sinus Floor Membrane During internal Sinus Floor Elevation With Implants at Different angles of the Maxillary Sinus angles
OBJECTIVE: This study analyzed and compared the biomechanical properties of maxillary sinus floor mucosa with implants at three different maxillary sinus angles during a modified internal sinus floor elevation procedure.
METHODS: 3D reconstruction of the implant, maxillary sinus bone, and membrane were performed. The maxillary sinus model was set at three different angles. Two internal maxillary sinus elevation models were established, and finite element analysis was used to simulate the modified maxillary sinus elevation process. The implant was elevated to 10 mm at three maxillary sinus angles when the maxillary sinus floor membrane was separated by 0 and 4 mm. The stress of the maxillary sinus floor membrane was analyzed and compared.
RESULTS: When the maxillary sinus floor membrane was separated by 0 mm and elevated to 10 mm, the peak stress values of the implant on the maxillary sinus floor membrane at three different angles were as follows: maxillary sinus I: 5.14-78.32 MPa; maxillary sinus II: 2.81-73.89 MPa; and maxillary sinus III: 2.82-51.87 MPa. When the maxillary sinus floor membrane was separated by 4 mm and elevated to 10 mm, the corresponding values were as follows: maxillary sinus I: 0.50-7.25 MPa; maxillary sinus II: 0.81-16.55 MPa; and maxillary sinus III: 0.49-22.74 MPa.
CONCLUSION: The risk of sinus floor membrane rupture is greatly reduced after adequate dissection of the maxillary sinus floor membrane when performing modified internal sinus elevation in a narrow maxillary sinus. In a wide maxillary sinus, the risk of rupture or perforation of the wider maxillary sinus floor is reduced, regardless of whether traditional or modified internal sinus elevation is performed at the same height
A Peer-to-peer Federated Continual Learning Network for Improving CT Imaging from Multiple Institutions
Deep learning techniques have been widely used in computed tomography (CT)
but require large data sets to train networks. Moreover, data sharing among
multiple institutions is limited due to data privacy constraints, which hinders
the development of high-performance DL-based CT imaging models from
multi-institutional collaborations. Federated learning (FL) strategy is an
alternative way to train the models without centralizing data from
multi-institutions. In this work, we propose a novel peer-to-peer federated
continual learning strategy to improve low-dose CT imaging performance from
multiple institutions. The newly proposed method is called peer-to-peer
continual FL with intermediate controllers, i.e., icP2P-FL. Specifically,
different from the conventional FL model, the proposed icP2P-FL does not
require a central server that coordinates training information for a global
model. In the proposed icP2P-FL method, the peer-to-peer federated continual
learning is introduced wherein the DL-based model is continually trained one
client after another via model transferring and inter institutional parameter
sharing due to the common characteristics of CT data among the clients.
Furthermore, an intermediate controller is developed to make the overall
training more flexible. Numerous experiments were conducted on the AAPM
low-dose CT Grand Challenge dataset and local datasets, and the experimental
results showed that the proposed icP2P-FL method outperforms the other
comparative methods both qualitatively and quantitatively, and reaches an
accuracy similar to a model trained with pooling data from all the
institutions
Doping and temperature dependence of electron spectrum and quasiparticle dispersion in doped bilayer cuprates
Within the t-t'-J model, the electron spectrum and quasiparticle dispersion
in doped bilayer cuprates in the normal state are discussed by considering the
bilayer interaction. It is shown that the bilayer interaction splits the
electron spectrum of doped bilayer cuprates into the bonding and antibonding
components around the point. The differentiation between the bonding
and antibonding components is essential, which leads to two main flat bands
around the point below the Fermi energy. In analogy to the doped
single layer cuprates, the lowest energy states in doped bilayer cuprates are
located at the point. Our results also show that the striking
behavior of the electronic structure in doped bilayer cuprates is intriguingly
related to the bilayer interaction together with strong coupling between the
electron quasiparticles and collective magnetic excitations.Comment: 9 pages, 4 figures, updated references, added figures and
discussions, accepted for publication in Phys. Rev.
Practice of Comparative Effectiveness Research to Identify Treatment Characteristics of Similar Chinese Patent Medicine for Angina Pectoris
Objective. Individualized application of TCM is not easy and may lead to undesirable results, such as poor effect or even adverse reactions. This trial aims to compare two common Chinese patent medicines with similar effects. Background of the Research. Four hospitals carried out the test at the same time in Tianjin city of China. Participants. 144 patients were involved in this study; all patients must meet the diagnostic criteria. Interventions. Qishen Yiqi pills, compound danshen pills, and their placebos; an efficacy analysis was conducted after the first medication and after crossover medication. Primary Outcome Measures. The primary index of end point includes Seattle Angina Questionnaire score-7 and score of 7-point Likert Scale; the curative effect was compared with minimal clinically important differences value. Result. Two drugs have their respective advantages in treating SAP. In practical application, the two drugs shall be discriminated in use based on patients’ specific symptoms. Trial Registration. Chinese clinical trials register is ChiCTR-TTRCC-14004406 (registered 23 March 2014)
An Experimental Study on the Establishment of Pulmonary Hypertension Model in Rats induced by Monocrotaline
Pulmonary hypertension is called PH for short. It is caused by the pulmonary artery vascular disease leading to pulmonary vascular resistance, and the increase right lung compartment load, which resulting in weakening or even collapse of the right ventricular function. The establishment of rat PH model under the action of monocrotaline is a repeatable, simple and accessible operation technique, which has been widely used in the treatment of pulmonary hypertension. This paper discusses the principle and properties of the PH model on rats under the monocrotaline action
Qishen Yiqi dripping pills for chronic ischaemic heart failure:results of the CACT-IHF randomized clinical trial
10.1002/ehf2.12980ESC Heart Failure763881-389
A new insight into the role of plasma fibrinogen in the development of metabolic syndrome from a prospective cohort study in urban Han Chinese population
Is the astronomical forcing a reliable and unique pacemaker for climate? A conceptual model study
There is evidence that ice age cycles are paced by astronomical forcing,
suggesting some kind of synchronisation phenomenon. Here, we identify the type
of such synchronisation and explore systematically its uniqueness and
robustness using a simple paleoclimate model akin to the van der Pol relaxation
oscillator and dynamical system theory. As the insolation is quite a complex
quasiperiodic signal involving different frequencies, the traditional concepts
used to define synchronisation to periodic forcing are no longer applicable.
Instead, we explore a different concept of generalised synchronisation in terms
of (coexisting) synchronised solutions for the forced system, their basins of
attraction and instabilities. We propose a clustering technique to compute the
number of synchronised solutions, each of which corresponds to a different
paleoclimate history. In this way, we uncover multistable synchronisation
(reminiscent of phase- or frequency-locking to individual periodic components
of astronomical forcing) at low forcing strength, and monostable or unique
synchronisation at stronger forcing. In the multistable regime, different
initial conditions may lead to different paleoclimate histories. To study their
robustness, we analyse Lyapunov exponents that quantify the rate of convergence
towards each synchronised solution (local stability), and basins of attraction
that indicate critical levels of external perturbations (global stability). We
find that even though synchronised solutions are stable on a long term, there
exist short episodes of desynchronisation where nearby climate trajectories
diverge temporarily (for about 50 kyr). (...)Comment: 22 pages, 18 figure
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