248 research outputs found
Molecular understanding of cell morphogenesis and cytokinesis in the fission yeast schizosaccharomyces pombe
Ph.DDOCTOR OF PHILOSOPH
Synthesis and kinetic analysis of hydromagnesite with different morphologies by nesquehonite method
514-521Hydromagnesite with different morphologies has been synthesized using self-made nesquehonite whiskers as raw materials. The synthesized samples have been characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that porous rod-like hydromagnesite are generated at 328~353K and in the pH value of 9.30+0.2, while irregular flower-like and flat layered ones are synthesized in the pH values of 10.0+0.05 and 11.0+0.05, respectively. The yield of hydromagnesite improved linearly with the increase of the temperatures and solution pH values. Porous rod-like hydromagneiste crystals with good crystalline and uniform morphology are obtained when the pyrolysis time is over 60 min. Furthermore, the apparent activation energy of phase transformation is calculated to be 3.4080 kJ/mol. According to the results, the experimental data can be well described by the kinetic model, suggesting that the phase transfer rate is dependent on the temperature
Self-supervised phase unwrapping in fringe projection profilometry
Fast-speed and high-accuracy three-dimensional (3D) shape measurement has
been the goal all along in fringe projection profilometry (FPP). The
dual-frequency temporal phase unwrapping method (DF-TPU) is one of the
prominent technologies to achieve this goal. However, the period number of the
high-frequency pattern of existing DF-TPU approaches is usually limited by the
inevitable phase errors, setting a limit to measurement accuracy.
Deep-learning-based phase unwrapping methods for single-camera FPP usually
require labeled data for training. In this letter, a novel self-supervised
phase unwrapping method for single-camera FPP systems is proposed. The trained
network can retrieve the absolute fringe order from one phase map of 64-period
and overperform DF-TPU approaches in terms of depth accuracy. Experimental
results demonstrate the validation of the proposed method on real scenes of
motion blur, isolated objects, low reflectivity, and phase discontinuity
Deep Learning-enabled Spatial Phase Unwrapping for 3D Measurement
In terms of 3D imaging speed and system cost, the single-camera system
projecting single-frequency patterns is the ideal option among all proposed
Fringe Projection Profilometry (FPP) systems. This system necessitates a robust
spatial phase unwrapping (SPU) algorithm. However, robust SPU remains a
challenge in complex scenes. Quality-guided SPU algorithms need more efficient
ways to identify the unreliable points in phase maps before unwrapping.
End-to-end deep learning SPU methods face generality and interpretability
problems. This paper proposes a hybrid method combining deep learning and
traditional path-following for robust SPU in FPP. This hybrid SPU scheme
demonstrates better robustness than traditional quality-guided SPU methods,
better interpretability than end-to-end deep learning scheme, and generality on
unseen data. Experiments on the real dataset of multiple illumination
conditions and multiple FPP systems differing in image resolution, the number
of fringes, fringe direction, and optics wavelength verify the effectiveness of
the proposed method.Comment: 26 page
Achieving Energy-Efficient Uplink URLLC with MIMO-Aided Grant-Free Access
The optimal design of the energy-efficient multiple-input multiple-output
(MIMO) aided uplink ultra-reliable low-latency communications (URLLC) system is
an important but unsolved problem. For such a system, we propose a novel
absorbing-Markov-chain-based analysis framework to shed light on the puzzling
relationship between the delay and reliability, as well as to quantify the
system energy efficiency. We derive the transition probabilities of the
absorbing Markov chain considering the Rayleigh fading, the channel estimation
error, the zero-forcing multi-user-detection (ZF-MUD), the grant-free access,
the ACK-enabled retransmissions within the delay bound and the interactions
among these technical ingredients. Then, the delay-constrained reliability and
the system energy efficiency are derived based on the absorbing Markov chain
formulated. Finally, we study the optimal number of user equipments (UEs) and
the optimal number of receiving antennas that maximize the system energy
efficiency, while satisfying the reliability and latency requirements of URLLC
simultaneously. Simulation results demonstrate the accuracy of our theoretical
analysis and the effectiveness of massive MIMO in supporting large-scale URLLC
systems.Comment: 14 pages, 9 figures, accepted to appear on IEEE Transactions on
Wireless Communications, Aug. 202
ANTIOXIDANTACTIVITY OF POLYPHENOLS FROM TOONA SINENSIS ROEM SEEDS AND THE INHIBITION OF ALDOSE REDUCTASE
Background: The seeds of Toona sinensis (Juss.) M. Roem (T. sinensis) have long been used in Traditional Chinese Medicine for the treatment of diabetes mellitus (DM) and its complications. The aim of this study was to investigate the antioxidant activity of different polyphenols fractions from Toona sinensis Roem (T. sinensis) seeds (PTSS) and the inhibition of aldose reductase (AR). Methods: Macroporous resin was used to purify PTSS, and the antioxidant activities were evaluated with total antioxidant capacity and free-radical scavenging. AR inhibitory activities were investigated by employing various established systems. Results: The polyphenol eluted by 60% alcohol (PTSS3) exhibit the highest antioxidant activity and AR inhibition, with an r value of 0.9924 ± 0.0066 in correlation analysis. The inhibition mechanism of PTSS3 on AR is uncompetitive inhibition. Conclusion: This research demonstrates that PTSS offers potential for intervening diabetes mellitus and its complications
Long-term retrospective assessment of a transmission hotspot for human alveolar echinococcosis in mid-west China
Background
Human alveolar echinococcosis caused by infection with Echinococcus multilocularis is one of the most potentially pathogenic helminthic zoonoses. Transmission occurs involving wildlife cycles typically between fox and small mammal intermediate hosts. In the late 1980s/early 1990s a large focus of human AE was identified in poor upland agricultural communities in south Gansu Province, China. More detailed investigations in 1994–97 expanded community screening and identified key risk factors of dog ownership and landscape type around villages that could support susceptible rodent populations. A crash of the dog population (susceptible domestic definitive host) in the early 1990s appeared to stop transmission.
Methodology/Findings
We subsequently undertook follow-up eco-epidemiological studies based on human population screening and dog survey, in 2005/6 and in 2014/15. Our observations show a decrease in human AE prevalence, especially marked in the 11–30 year old age category. In 2015, although the dog population had recovered and in addition, forest protection and the reforestation of some areas may have favoured red fox (wild definitive host) population growth, there was no evidence of infection in owned dogs.
Conclusions/Significance
Those observations suggest that over decades socio-ecological changes resulted in a cascade of factors that exacerbated and then interrupted parasite emergence, with probable elimination of peri-domestic transmission of E. multilocularis in this area, despite the relative proximity of large active transmission foci on the eastern Tibetan Plateau. This study case exemplifies how anthropogenic land use and behavioural changes can modify emergence events and the transmission of endemic zoonotic parasite infections, and subsequently the importance of considering processes over the long-term in a systems approach in order to understand pathogen and disease distribution
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