27 research outputs found
Endobronchial Lipoma: An Unusual Cause of Bronchial Obstruction
Endobronchial lipoma is a rare benign tumor. It is difficult to differentiate benign endobronchial lipoma from their malignant counterparts, as their symptoms and complications are almost alike. Here, we describe the clinical and radiological features of EL in two cases. Multislice CT (MSCT) may play an important role in the diagnosis for EL
A direct unified wave-particle method for simulating non-equilibrium flows
In this work, the Navier-Stokes (NS) solver is combined with the Direct
simulation Monte Carlo (DSMC) solver in a direct way, under the wave-particle
formulation [J. Comput. Phys. 401, 108977 (2020)]. Different from the classical
domain decomposition method with buffer zone for overlap, in the proposed
direct unified wave-particle (DUWP) method, the NS solver is coupled with DSMC
solver on the level of algorithm. Automatically, in the rarefied flow regime,
the DSMC solver leads the simulation, while the NS solver leads the continuum
flow simulation. Thus advantages of accuracy and efficiency are both taken. At
internal flow regimes, like the transition flow regime, the method is accurate
as well because a kind of mesoscopic modeling is proposed in this work, which
gives the DUWP method the multi-scale property. Specifically, as to the
collision process, at , it is supposed that only single collision
happens, and the collision term of DSMC is just used. At , it is
derived that of particles should experience multiple
collisions, which will be absorbed into the wave part and calculated by the NS
solver. Then the DSMC and NS solver can be coupled in a direct and simple way,
bringing about multi-scale property. The governing equation is derived and
named as multi-scale Boltzmann equation. Different from the original
wave-particle method, in the proposed DUWP method, the wave-particle
formulation is no more restricted by the Boltzmann-BGK type model and the
enormous research findings of DSMC and NS solvers can be utilized into much
more complicated flows, like the thermochemical non-equilibrium flow. In this
work, one-dimensional cases in monatomic argon gas are preliminarily tested,
such as shock structures and Sod shock tubes
ASSIST: Interactive Scene Nodes for Scalable and Realistic Indoor Simulation
We present ASSIST, an object-wise neural radiance field as a panoptic
representation for compositional and realistic simulation. Central to our
approach is a novel scene node data structure that stores the information of
each object in a unified fashion, allowing online interaction in both intra-
and cross-scene settings. By incorporating a differentiable neural network
along with the associated bounding box and semantic features, the proposed
structure guarantees user-friendly interaction on independent objects to scale
up novel view simulation. Objects in the scene can be queried, added,
duplicated, deleted, transformed, or swapped simply through mouse/keyboard
controls or language instructions. Experiments demonstrate the efficacy of the
proposed method, where scaled realistic simulation can be achieved through
interactive editing and compositional rendering, with color images, depth
images, and panoptic segmentation masks generated in a 3D consistent manner
The association of long-term trajectories of BMI, its variability, and metabolic syndrome: a 30-year prospective cohort study
Background
Limited data exists on how early-life weight changes relate to metabolic syndrome (MetS) risk in midlife. This study examines the association between long-term trajectories of body mass index (BMI), its variability, and MetS risk in Chinese individuals.
Methods
In the Hanzhong Adolescent Hypertension study (March 10, 1987–June 3, 2017), 1824 participants with at least five BMI measurements from 1987 to 2017 were included. Using group-based trajectory modeling, different BMI trajectories were identified. BMI variability was assessed through standard deviation (SD), variability independent of the mean (VIM), and average real variability (ARV). Logistic regression analyzed the relationship between BMI trajectory, BMI variability, and MetS occurrence in midlife (URL: https://www.clinicaltrials.gov; Unique identifier: NCT02734472).
Findings
BMI trajectories were categorized as low-increasing (34.4%), moderate-increasing (51.8%), and high-increasing (13.8%). Compared to the low-increasing group, the odds ratios (ORs) [95% CIs] for MetS were significantly higher in moderate (4.27 [2.63–6.91]) and high-increasing groups (13.11 [6.30–27.31]) in fully adjusted models. Additionally, higher BMI variabilities were associated with increased MetS odds (ORs for SDBMI, VIMBMI, and ARVBMI: 2.30 [2.02–2.62], 1.22 [1.19–1.26], and 4.29 [3.38–5.45]). Furthermore, BMI trajectories from childhood to adolescence were predictive of midlife MetS, with ORs in moderate (1.49 [1.00–2.23]) and high-increasing groups (2.45 [1.22–4.91]). Lastly, elevated BMI variability in this period was also linked to higher MetS odds (ORs for SDBMI, VIMBMI, and ARVBMI: 1.24 [1.08–1.42], 1.00 [1.00–1.01], and 1.21 [1.05–1.38]).
Interpretation
Our study suggests that both early-life BMI trajectories and BMI variability could be predictive of incident MetS in midlife
Experimental quantum computational chemistry with optimised unitary coupled cluster ansatz
Simulation of quantum chemistry is one of the most promising applications of
quantum computing. While recent experimental works have demonstrated the
potential of solving electronic structures with variational quantum eigensolver
(VQE), the implementations are either restricted to nonscalable (hardware
efficient) or classically simulable (Hartree-Fock) ansatz, or limited to a few
qubits with large errors for the more accurate unitary coupled cluster (UCC)
ansatz. Here, integrating experimental and theoretical advancements of improved
operations and dedicated algorithm optimisations, we demonstrate an
implementation of VQE with UCC for H_2, LiH, F_2 from 4 to 12 qubits. Combining
error mitigation, we produce high-precision results of the ground-state energy
with error suppression by around two orders of magnitude. For the first time,
we achieve chemical accuracy for H_2 at all bond distances and LiH at small
bond distances in the experiment. Our work demonstrates a feasible path towards
a scalable solution to electronic structure calculation, validating the key
technological features and identifying future challenges for this goal.Comment: 8 pages, 4 figures in the main text, and 29 pages supplementary
materials with 16 figure
Detection of CTX-M-15 Extended-Spectrum β-Lactamases Producing Escherichia coli Isolates from Colostrum and Faeces of Newborn Dairy Calves in China
Newborn dairy calves are often colonized by multidrug-resistant (MDR) extended-spectrum β-Lactamase producing Escherichia coli (ESBL-EC), which pose significant risks to global healthcare. As the first meal of calves, the role of dairy colostrum as a potential source of MDR-E. coli has not been well-studied. Here, we report on similar antibiotic resistance patterns of E. coli strains, isolated from colostrum fed to dairy calves and their faeces. Four ESBL-EC strains from colostrum and faeces of newborn dairy calves were isolated by double-disc synergy testing and multiplex PCR. Strikingly, isolates from colostrum or faeces were found to have similar MDR profiles, showing a high resistance to cephalosporins and other conventional antibiotics. In addition, coexistence of blaCTX-M-15 and blaTEM-171 was detected on a self-transferable plasmid with a typical IncHI2 backbone. To the best of our knowledge, this is the first case reporting on ESBL-EC strains carrying blaCTX-M-15 and blaTEM-171 genes, and isolated from faeces and the colostrum stock fed to the dairy calves
Inertia estimation of power system with new energy considering with high renewable penetrations
The emerging energy technologies, such as wind energy and photovoltaic (PV), will gradually replace the traditional synchronous generator in wide-area power system. As the wind, PV and energy storage equipment are all controlled by power electronic inverters, which are decoupled from the system and cannot provide effective inertial support to the power system with new energy (PS-NE), resulting in stability problems caused by the low inertia of the PS-NE. In particular, this paper investigates the inertia response of synchronous generator and PS-NE, and the inertia model of PS-NE considering with high renewable penetrations. Then the relation between inertia and frequency of PS-NE with high renewable penetrations are explored in this paper. Besides, the real-time inertia of the PS-NE is estimated by using the statistical algorithm based on the historical data of the PS-NE, and the range of the inertia and synchronous generator start-up capacity of the PS-NE can be estimated by using the statistical algorithm based on the renewable penetrations when we cannot obtain the historical data of the PS-NE. In addition, IEEE39 system of PS-NE is used to verify the relation between inertia and frequency of PS-NE with high renewable penetrations, and the inertia estimation of PS-NE with high renewable penetrations is analyzed in this paper