70 research outputs found
Positron trapping at the effective open volume in FeCr alloy containing hydrogen/helium atoms
4th Japan-China Joint Workshop on Positron Science (JWPS2019)Positron annihilation spectroscopy (PAS) is a sensitive probe of the shallow traps of light charged particles such as He/H embedded in solids. The nature of the shallow traps that attract positronsāi.e., whether the properties of the light charged particles or the number of particles contained in the traps affects the probability of positron captureāhas so far remained unresolved. Here, the shallow traps of positron in FeCr alloy, namely (H, He)āV nano-clusters with open volume, have been investigated by first-principles calculations and a multi-grid based program package for electronic structure calculations. Various defect structures were modeled, including vacancies, interstitial helium atoms, and helium or hydrogen atoms occupying Fe vacancy sites. We calculated the charge density distribution at the (H, He)āV nano-clusters, and the results show that the charge density at the He/HāV clusters is significantly lower than around the neighboring Fe/Cr sites. The calculated lifetimes of positrons confined in the shallow traps are consistent with the effective open volume of the (H, He)āV complexes. These results suggest that a helium atom forms a more repulsive ion core than a hydrogen atom when it occupies the vacancy, resulting in a decrease in positron lifetime
Towards Vehicle-to-everything Autonomous Driving: A Survey on Collaborative Perception
Vehicle-to-everything (V2X) autonomous driving opens up a promising direction
for developing a new generation of intelligent transportation systems.
Collaborative perception (CP) as an essential component to achieve V2X can
overcome the inherent limitations of individual perception, including occlusion
and long-range perception. In this survey, we provide a comprehensive review of
CP methods for V2X scenarios, bringing a profound and in-depth understanding to
the community. Specifically, we first introduce the architecture and workflow
of typical V2X systems, which affords a broader perspective to understand the
entire V2X system and the role of CP within it. Then, we thoroughly summarize
and analyze existing V2X perception datasets and CP methods. Particularly, we
introduce numerous CP methods from various crucial perspectives, including
collaboration stages, roadside sensors placement, latency compensation,
performance-bandwidth trade-off, attack/defense, pose alignment, etc. Moreover,
we conduct extensive experimental analyses to compare and examine current CP
methods, revealing some essential and unexplored insights. Specifically, we
analyze the performance changes of different methods under different
bandwidths, providing a deep insight into the performance-bandwidth trade-off
issue. Also, we examine methods under different LiDAR ranges. To study the
model robustness, we further investigate the effects of various simulated
real-world noises on the performance of different CP methods, covering
communication latency, lossy communication, localization errors, and mixed
noises. In addition, we look into the sim-to-real generalization ability of
existing CP methods. At last, we thoroughly discuss issues and challenges,
highlighting promising directions for future efforts. Our codes for
experimental analysis will be public at
https://github.com/memberRE/Collaborative-Perception.Comment: 19 page
Correlation between inflammatory marker and lipid metabolism in patients with uterine leiomyomas
IntroductionObesity is a risk factor for the development of uterine leiomyoma (UL), and the inflammatory response plays a key role in the pathogenesis of UL. Our objective was to assess whether there was an independent relationship between inflammatory markers and triglycerides (TG) in patients with UL.Methods1,477 UL participants who were hospitalized at the Jining Medical University between January 2016 and December 2022 were included in this cross-sectional study. The independent and dependent variables measured at baseline were inflammatory markers and TG levels, respectively. The covariates were age, body mass index (BMI), UL and menstrual status. Based on the number of fibroids, the study population was divided into Single-group and Multiple-group.ResultsUnivariate and multiple regression analyses and stratified analyses revealed significant positive correlations between neutrophil-lymphocyte ratio and systemic immune inflammation index and TG, and significant negative correlations between monocyte-lymphocyte ratio and TG.ConclusionThe findings show a significant correlation between the inflammatory response and lipid metabolism levels in UL patients. This provides direction for further research into the pathophysiology of UL and also helps to formulate hypotheses for predictive models of UL
Predicting Housekeeping Genes Based on Fourier Analysis
Housekeeping genes (HKGs) generally have fundamental functions in basic biochemical processes in organisms, and usually have relatively steady expression levels across various tissues. They play an important role in the normalization of microarray technology. Using Fourier analysis we transformed gene expression time-series from a Hela cell cycle gene expression dataset into Fourier spectra, and designed an effective computational method for discriminating between HKGs and non-HKGs using the support vector machine (SVM) supervised learning algorithm which can extract significant features of the spectra, providing a basis for identifying specific gene expression patterns. Using our method we identified 510 human HKGs, and then validated them by comparison with two independent sets of tissue expression profiles. Results showed that our predicted HKG set is more reliable than three previously identified sets of HKGs
Constraints of SāPbāSr Isotope Compositions and RbāSr Isotopic Age on the Origin of the Laoyingqing Noncarbonate-Hosted PbāZn Deposit in the Kunyang Group, SW China
The Laoyingqing PbāZn deposit is located on the southwestern margin of the Yangtze block and on the east side of the Xiaojiang deep fault in the SichuanāYunnanāGuizhou PbāZn metallogenic triangle area (SYGT). This deposit was first discovered in the silty and carbonaceous slate of the Middle Proterozoic Kunyang Group that is structurally controlled by thrust faults and anticlines. This study is aimed at investigating whether the Laoyingqing deposit has the same ore-forming age and type as other PbāZn deposits related to the PbāZn metallogenic system and prospecting prediction of the deep and peripheral areas of the deposits in the SYGT. Based on the sphalerite RbāSr age dating and SāSrāPb isotopic composition analysis of the Laoyingqing PbāZn deposit, the following results were obtained. First, the RbāSr isochron age of sphalerite is 209.8Ā±5.2 million years (Ma), consistent with the ages of most PbāZn deposits in the SYGT (approximately 200Ma), thereby potentially indicating that these PbāZn deposits may have been formed synchronously during the late Indosinian orogeny. Second, the Pb isotopic compositions of sulfides show a linear trend on the average crustal Pb evolution curve in 207Pb/204Pb vs. 206Pb/204Pb plot. In addition, Pb isotopic ratios were consistent with the age-corrected Pb isotopic ratios of basement rocks, consequently suggesting that the source of mixed crustal Pb is mainly derived from basement rocks. Combined with the initial 87Sr/86Sr ratios of sphalerite between the (87Sr/86Sr)200Ma value of the basement rocks and that of the Upper SinianāPermian carbonates, it can be concluded that the ore-forming metals were mainly derived from basement rocks. Third, sulfur isotopic composition of sphalerite from the Laoyingqing deposits shows Ī“34SCDT values that range mainly from -2.62ā° to 1.42ā°, which is evidently lower than the Ī“34SCDT values of sulfides (8ā20ā°) from other PbāZn deposits in the SYGT. This can be interpreted as a result of mixing with reduced S that was mainly derived from the thermochemically reduced S in the overlying strata and a small amount of reduced S produced by the pyrolysis of S-containing organic matter. We conclude that the Laoyingqing deposit and most of the PbāZn deposits in the SYGT are Mississippi Valley-type deposits, thereby providing new ideas for investigating the deep and peripheral areas of PbāZn deposits
ACACA reduces lipid accumulation through dual regulation of lipid metabolism and mitochondrial function via AMPK- PPARĪ±- CPT1A axis
Abstract Background Non-alcoholic fatty liver disease (NAFLD) is a multifaceted metabolic disorder, whose global prevalence is rapidly increasing. Acetyl CoA carboxylases 1 (ACACA) is the key enzyme that controls the rate of fatty acid synthesis. Hence, it is crucial to investigate the function of ACACA in regulating lipid metabolism during the progress of NAFLD. Methods Firstly, a fatty liver mouse model was established by high-fat diet at 2nd, 12th, and 20th week, respectively. Then, transcriptome analysis was performed on liver samples to investigate the underlying mechanisms and identify the target gene of the occurrence and development of NAFLD. Afterwards, lipid accumulation cell model was induced by palmitic acid and oleic acid (PA ā¶ OA molar ratioā=ā1ā¶2). Next, we silenced the target gene ACACA using small interfering RNAs (siRNAs) or the CMS-121 inhibitor. Subsequently, experiments were performed comprehensively the effects of inhibiting ACACA on mitochondrial function and lipid metabolism, as well as on AMPK- PPARĪ±- CPT1A pathway. Results This data indicated that the pathways significantly affected by high-fat diet include lipid metabolism and mitochondrial function. Then, we focus on the target gene ACACA. In addition, the in vitro results suggested that inhibiting of ACACA in vitro reduces intracellular lipid accumulation, specifically the content of TG and TC. Furthermore, ACACA ameliorated mitochondrial dysfunction and alleviate oxidative stress, including MMP complete, ATP and ROS production, as well as the expression of mitochondria respiratory chain complex (MRC) and AMPK proteins. Meanwhile, ACACA inhibition enhances lipid metabolism through activation of PPARĪ±/CPT1A, leading to a decrease in intracellular lipid accumulation. Conclusion Targeting ACACA can reduce lipid accumulation by mediating the AMPK- PPARĪ±- CPT1A pathway, which regulates lipid metabolism and alleviates mitochondrial dysfunction
Dynamic bandgap responsiveness of modified re-entrant metamaterials in thermal-mechanical field
This paper introduces a nested sinusoidal re-entrant (NSR) metamaterial characterized by tunable complete bandgaps (CBGs) and dynamic responsiveness in thermal-mechanical dual fields. NSR comprises shape memory polymer and features a sinusoidal modification with nested re-entrant hexagonal and star-shape re-entrant structure. Dynamic response of NSR is studied using the representative volume element method, specifically focusing on the effective modulus and Poisson's ratio and CBGs under varying average strains. The findings indicate that both the mechanical properties and CBGs exhibit dynamic responses to mechanical field, demonstrating interrelation between mechanical adjustments and functional performance. Moreover, the study examines how temperature fluctuations influence the NSR's elastic modulus, thereby altering its CBGs. Hence, manipulating both compression and temperature variations presents a viable approach to control and adjust the CBGs of NSR effectively. These results are validated by computations of the frequency response function under various average strains. Overall, this design presents a promising approach for developing mechanical metamaterials with tunable functionality
Novel self-similar re-entrant auxetic metamaterials (SREAM): Design, mechanical property, and geometric optimization
In this study, a novel self-similar re-entrant auxetic metamaterial (SREAM) was designed to improve its mechanical performance compared with the conventional re-entrant structure (CRS). Experimental and numerical analyses were carried out to investigate their mechanical performance under quasi-static compression. The mechanical effects of key geometric parameters of inner re-entrants have also been symmetrically investigated to provide the modeling basis for SREAMsā geometric optimization. It was found that SREAM do well in both stiffness and auxeticity simultaneously. The mechanical performance of SREAMs is highly adjustable via proper configuration on geometric parameters. The proposed SREAM possibly provides superior auxeticity and high stiffness, with adjustable performance
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