306 research outputs found
Remarkably strong chemisorption of nitric oxide on insulating oxide films promoted by hybrid structure
The remarkably strong chemical adsorption behaviors of nitric oxide on
magnesia (001) film deposited on metal substrate have been investigated by
employing periodic density functional calculations with Van der Waals
corrections. The molybdenum supported magnesia (001) show significantly
enhanced adsorption properties and the nitric oxide is chemisorbed strongly and
preferably trapped in flat adsorption configuration on metal supported oxide
film, due to the substantially large adsorption energies and transformation
barriers. The analysis of Bader charges, projected density of states,
differential charge densities, electron localization function, highest occupied
orbital and particular orbital with largest Mg-NO-Mg bonding coefficients, are
applied to reveal the electronic adsorption properties and characteristics of
bonding between nitric oxide and surface as well as the bonding within the
hybrid structure. The strong chemical binding of nitric oxide on magnesia
deposited on molybdenum slab offers new opportunities for toxic gas detection
and treatment. We anticipate that hybrid structure promoted remarkable chemical
adsorption of nitric oxide on magnesia in this study will provide versatile
strategy for enhancing chemical reactivity and properties of insulating oxide
TacIPC: Intersection- and Inversion-free FEM-based Elastomer Simulation For Optical Tactile Sensors
Tactile perception stands as a critical sensory modality for human
interaction with the environment. Among various tactile sensor techniques,
optical sensor-based approaches have gained traction, notably for producing
high-resolution tactile images. This work explores gel elastomer deformation
simulation through a physics-based approach. While previous works in this
direction usually adopt the explicit material point method (MPM), which has
certain limitations in force simulation and rendering, we adopt the finite
element method (FEM) and address the challenges in penetration and mesh
distortion with incremental potential contact (IPC) method. As a result, we
present a simulator named TacIPC, which can ensure numerically stable
simulations while accommodating direct rendering and friction modeling. To
evaluate TacIPC, we conduct three tasks: pseudo-image quality assessment,
deformed geometry estimation, and marker displacement prediction. These tasks
show its superior efficacy in reducing the sim-to-real gap. Our method can also
seamlessly integrate with existing simulators. More experiments and videos can
be found in the supplementary materials and on the website:
https://sites.google.com/view/tac-ipc
PO-167 Effects of Hydrogen-rich Water on Rat Skeletal Muscles' Oxidative Damage and Autophagy Induced by Repeated Exhaustive Exercise
Objective This study was carried out to detect the effects of hydrogen-water intervention on oxidative stress and cell autophagy in skeletal muscle of rats with repeated exhaustion.
Methods 30 male SD rats in the age of 3 months, weighing 180-210g, were randomly divided into control group (C), repeated exhaustion group (EX), and the repeated exhaustion with hydrogen intervention group (EH), 10 rats in each group. The EX and EH groups were subjected to a four-weeks of repeated-exhaustive exercise. The initial speed of the exercise was 15 m/min, and increasedby 5 m/min every 5 min, the final speed is 35m/min until exhaustion, 5 d/wk, with a total of 4 wk. In EH group, hydro-water was given to rats 30 mins before exercise. The ultrastructural changes of skeletal muscle were observed by using a transmission electron microscopy. Activity of SDH and CK in serum and SOD activity, MDA content and T-AOC level in skeletal muscle tissue were detected. Western blotting was used to detect the proteins expression of autophagy related proteins in skeletal muscle, mTOR, p-mTOR, LC3B-2 and P53.
Results Compared with the EX group, in the EH group, the ultrastructural damage and mitochondrial swelling were significantly reduced, and the time of exhaustion was significantly prolonged (p<0.05), Serum SDH activity increased significantly (p<0.05), CK activity decreased significantly (p<0.05), and skeletal muscle tissue SOD activity and total antioxidant capacity significantly increased (p<0.05), MDA content decreased significantly (p<0.01), mTOR and p-mTOR protein expression was significantly increased(p<0.05), the LC3B-2 and P53 protein expression was significantly lower (p<0.05).
Conclusions Hydrogen water intervention could significantly improve repeatedly exhaustion exercise result in rat skeletal muscle injury, oxidative stress and cell ultrastructure damage excessive autophagy, improving oxidation resistance of the skeletal muscle and exercise endurance
CREPES: Cooperative RElative Pose Estimation System
Mutual localization plays a crucial role in multi-robot cooperation. CREPES,
a novel system that focuses on six degrees of freedom (DOF) relative pose
estimation for multi-robot systems, is proposed in this paper. CREPES has a
compact hardware design using active infrared (IR) LEDs, an IR fish-eye camera,
an ultra-wideband (UWB) module and an inertial measurement unit (IMU). By
leveraging IR light communication, the system solves data association between
visual detection and UWB ranging. Ranging measurements from the UWB and
directional information from the camera offer relative 3-DOF position
estimation. Combining the mutual relative position with neighbors and the
gravity constraints provided by IMUs, we can estimate the 6-DOF relative pose
from a single frame of sensor measurements. In addition, we design an estimator
based on the error-state Kalman filter (ESKF) to enhance system accuracy and
robustness. When multiple neighbors are available, a Pose Graph Optimization
(PGO) algorithm is applied to further improve system accuracy. We conduct
enormous experiments to demonstrate CREPES' accuracy between robot pairs and a
team of robots, as well as performance under challenging conditions
Effect of low frequency magnetic fields on melanoma: tumor inhibition and immune modulation
BACKGROUND: We previously found that the low frequency magnetic fields (LF-MF) inhibited gastric and lung cancer cell growth. We suppose that exposure to LF-MF may modulate immune function so as to inhibit tumor. We here investigated whether LF-MF can inhibit the proliferation and metastasis of melanoma and influence immune function. METHODS: The effect of MF on the proliferation, cell cycle and ultrastracture of B16-F10 in vitro was detected by cell counting Kit-8 assay, flow cytometry, and transmission electron microscopy. Lung metastasis mice were prepared by injection of 2 × 10(5) B16-F10 melanoma cells into the tail vein in C57BL/6 mice. The mice were then exposed to an LF-MF (0.4 T, 7.5 Hz) for 43 days. Survival rate, tumor markers and the innate and adaptive immune parameters were measured. RESULTS: The growth of B16-F10 cells was inhibited after exposure to the LF-MF. The inhibition was related to induction of cell cycle arrest and decomposition of chromatins. Moreover, the LF-MF prolonged the mouse survival rate and inhibited the proliferation of B16-F10 in melanoma metastasis mice model. Furthermore, the LF-MF modulated the immune response via regulation of immune cells and cytokine production. In addition, the number of Treg cells was decreased in mice with the LF-MF exposure, while the numbers of T cells as well as dendritic cells were significantly increased. CONCLUSION: LF-MF inhibited the growth and metastasis of melanoma cancer cells and improved immune function of tumor-bearing mice. This suggests that the inhibition may be attributed to modulation of LF-MF on immune function and LF-MF may be a potential therapy for treatment of melanoma
Ultrafast field-driven monochromatic photoemission from carbon nanotubes
Ultrafast electron pulses, combined with laser-pump and electron-probe
technologies, allow for various forms of ultrafast microscopy and spectroscopy
to elucidate otherwise challenging to observe physical and chemical
transitions. However, the pursuit of simultaneous ultimate spatial and temporal
resolution has been largely subdued by the low monochromaticity of the electron
pulses and their poor phase synchronization to the optical excitation pulses.
State-of-the-art photon-driven sources have good monochromaticity but poor
phase synchronization. In contrast, field-driven photoemission has much higher
light phase synchronization, due to the intrinsic sub-cycle emission dynamics,
but poor monochromaticity. Such sources suffer from larger electron energy
spreads (3 - 100 eV) attributed to the relatively low field enhancement of the
conventional metal tips which necessitates long pump wavelengths (> 800 nm) in
order to gain sufficient ponderomotive potential to access the field-driven
regime. In this work, field-driven photoemission from ~1 nm radius carbon
nanotubes excited by a femtosecond laser at a short wavelength of 410 nm has
been realized. The energy spread of field-driven electrons is effectively
compressed to 0.25 eV outperforming all conventional ultrafast electron
sources. Our new nanotube-based ultrafast electron source opens exciting
prospects for attosecond imaging and emerging light-wave electronics
Relation between surface solitons and bulk solitons in nonlocal nonlinear media
We find that a surface soliton in nonlocal nonlinear media can be regarded as
a half of a bulk soliton with an antisymmetric amplitude distribution. The
analytical solutions for the surface solitons and breathers in strongly
nonlocal media are obtained, and the critical power and breather period are
gotten analytically and confirmed by numerical simulations. In addition, the
oscillating propagation of nonlocal surface solitons launched away from the
stationary position is considered as the interaction between the soliton and
its out-of-phase image beam. Its trajectory and oscillating period obtained by
our model are in good agreement with the numerical simulations.Comment: 12 pages, 8 figures, 39 reference, Accepted by Opt. Expres
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