37 research outputs found
Elimination of degenerate trajectory of single atom strongly coupled to the tilted cavity TEM10 mode
We demonstrate the trajectory measurement of the single neutral atoms
deterministically using a high-finesse optical micro-cavity. Single atom
strongly couples to the high-order transverse vacuum TEM_{10} mode, instead of
the usual TEM_{00} mode, and the parameter of the system is (g_{10},\kappa
,\gamma )=2\pi \times (20.5,2.6,2.6)MHz. The atoms simply fall down freely from
the magneto-optic trap into the cavity modes and the trajectories of the single
atoms are linear. The transmission spectrums of atoms passing through the TEM10
mode are detected by a single photon counting modules and well fitted. Thanks
to the tilted cavity transverse TEM10 mode, which is inclined to the vertical
direction about 45 degrees and it helps us, for the first time, to eliminate
the degenerate trajectory of the single atom falling through the cavity and get
the unique atom trajectory. Atom position with high precision of 0.1{\mu}m in
the off-axis direction (axis y) is obtained, and the spatial resolution of
5.6{\mu}m is achieved in time of 10{\mu}s along the vertical direction (axis
x). The average velocity of the atoms is also measured from the atom transits,
which determines the temperature of the atoms in magneto-optic trap, 186{\mu}K
{\pm} 19{\mu}K.Comment: 13 pages, 5figure
Anti-endometriosis Mechanism of Jiawei Foshou San Based on Network Pharmacology
Jiawei Foshou San (JFS) is the new formula originated from classic Foshou San formula, composed with ligustrazine, ferulic acid, and tetrahydropalmatine. Previously JFS inhibited the growth of endometriosis (EMS) with unclear mechanism, especially in metastasis, invasion, and epithelial–mesenchymal transition. In this study, network pharmacology was performed to explore potential mechanism of JFS on EMS. Through compound–compound target and compound target–EMS target networks, key targets were analyzed for pathway enrichment. MMP–TIMP were uncovered as one cluster of the core targets. Furthermore, autologous transplantation of EMS rat’s model were used to evaluate in vivo effect of JFS on invasion, metastasis and epithelial–mesenchymal transition. JFS significantly suppressed the growth, and reduced the volume of ectopic endometrium, with modification of pathologic structure. In-depth study, invasion and metastasis were restrained after treating with JFS through decreasing MMP-2 and MMP-9, increasing TIMP-1. Meanwhile, JFS promoted E-cadherin, and attenuated N-cadherin, Vimentin, Snail, Slug, ZEB1, ZEB2, Twist. In brief, anti-EMS effect of JFS might be related to the regulation of epithelial–mesenchymal transformation, thereby inhibition of invasion and metastasis. These findings reveal the potential mechanism of JFS on EMS and the benefit for further evaluation
Fish Oil Intake During Gestation and Lactation Attenuated STZ-Induced Diabetes inMale Offspring via Activation of Brown Fat and Modulating Oxylipin Profile
Fish oil (FO) has been demonstrated to activate brown thermogenesis and attenuate inflammation in the brown adipose tissue (BAT). Previously, we have reported thatmaternal FO supplementation promotes BAT activity of the weaned mice pups. However, whether maternal FO intake could confer sustainable metabolic benefits to offspring remains uncovered. Therefore, this study aimed to determine the differential impact of maternal FO during pregnancy versus lactation on BAT transcriptome and evaluate the role of bioactive lipid metabolites derived from maternal FO supplementation on the extended metabolic benefits of older pups in the context of type 1 diabetes (T1D).
Conclusions: Our results suggested that maternal FO intake in pregnancy and lactation, at least partly, protects against the risk of T1D of the offspring through augmented BAT function and antiinflammatory oxylipin production
Human IL-17 and TNF-α Additively or Synergistically Regulate the Expression of Proinflammatory Genes, Coagulation-Related Genes, and Tight Junction Genes in Porcine Aortic Endothelial Cells
Immune rejection is the major limitation for porcine xenograft survival in primate recipients. Proinflammatory cytokines play important roles in immune rejection and have been found to mediate the pathological effects in various clinical and experimental transplantation trials. IL-17 and TNF-α play critical pathological roles in immune disorders, such as psoriasis and rheumatoid arthritis. However, the pathological roles of human IL-17 (hIL-17) and human TNF-α (hTNF-α) in xenotransplantation remain unclear. Here we found that hIL-17 and hTNF-α additively or synergistically regulate the expression of 697 genes in porcine aortic endothelial cells (PAECs). Overall, 415 genes were found to be synergistically regulated, while 282 genes were found to be additively regulated. Among these, 315 genes were upregulated and 382 genes were downregulated in PAECs. Furthermore, we found that hIL-17 and hTNF-α additively or synergistically induced the expression of various proinflammatory cytokines and chemokines (e.g., IL1α, IL6, and CXCL8) and decreased the expression of certain anti-inflammatory genes (e.g., IL10). Moreover, hIL-17 plus hTNF-α increased the expression of IL1R1 and IL6ST, receptors for IL1 and IL6, respectively, and decreased anti-inflammatory gene receptor expression (IL10R). hIL-17 and hTNF-α synergistically or additively induced CXCL8 and CCL2 expression and consequently promoted primary human neutrophil and human leukemia monocytic cell migration, respectively. In addition, hIL-17 and hTNF-α induced pro-coagulation gene (SERPINB2 and F3) expression and decreased anti-coagulation gene (TFPI, THBS1, and THBD) expression. Additionally, hIL-17 and hTNF-α synergistically decreased occludin expression and consequently promoted human antibody-mediated complement-dependent cytotoxicity. Interestingly, hTNF-α increased swine leukocyte antigen (SLA) class I expression; however, hIL-17 decreased TNF-α-mediated SLA-I upregulation. We concluded that hIL-17 and hTNF-α likely promote the inflammatory response, coagulation cascade, and xenoantibody-mediated cell injury. Thus, blockade of hIL-17 and hTNF-α together might be beneficial for xenograft survival in recipients
Use Reinforcement Learning to Generate Testing Commands for Onboard Software of Small Satellites
Programmers usually write test cases to test onboard software. However, this procedure is time-consuming and needs sufficient prior knowledge. As a result, small satellite developers may not be able to test the software thoroughly. A promising direction to solve this problem is reinforcement learning (RL) based testing. It searches testing commands to maximise the return, which represents the testing goal. Testers need not specify prior knowledge besides the reward function and hyperparameters. Reinforcement learning has matured in software testing scenarios, such as GUI testing. However, migration from such scenarios to onboard software testing is still challenging because of different environments. This work is the first research to apply reinforcement learning in real onboard software testing and one of few studies that perform RL-based testing on embedded software without a GUI. In this work, the RL agent observes current code coverage and the interaction history, selects a pre-defined command, or organises a command from pre-defined parameters to maximise cumulative reward. The reward function can be code coverage (coverage testing) or estimated CPU load (stress testing). Three RL algorithms, including the tabular Q-Learning, Double Duelling Deep Q Network (D3QN), and Proximal Policy Optimization (PPO), are compared with a random testing baseline and a genetic algorithm baseline in the experiments. This study also performs regression testing with a trained RL agent, i.e., to test a version of onboard software that it has never seen before. To do that, the agent processes graph input with code coverage information. The graph is extracted from the onboard software source code via static code analysis. The work tries two graph neural network architectures (GGNN and GAT) with several graph pooling mechanisms to process the graph input. Apart from the test command generation algorithms, some middleware is also implemented, including a command/response parser, a state identification module, a branch coverage collection tool, and a tool to extract the graph representation and node features. During onboard software testing, the onboard computer (OBC) or the electrical group support equipment (EGSE) can be the master of the bus. The command generation algorithms can run on a lab PC or a cloud server. The research reveals the advantages and drawbacks of using reinforcement learning to test onboard software. On the one hand, RL-based testing performs well in non-deterministic environments (e.g., stress testing) and regression testing. On the other hand, more straightforward methods like random testing and the genetic algorithm are more useful in deterministic environments. This document also introduces relative background knowledge. It leaves many recommendations for future work, such as improving sampling efficiency, generalization, and learning a model for fault detection in satellite operation.https://github.com/StarCycle/TestCommandGeneration Testing command generation algorithms https://github.com/StarCycle/CodeCoverage Code Coverage Collection and Analysing Tool https://github.com/StarCycle/GraphExtract Graph Representation Extraction ToolDelfi-PocketQubeAerospace Engineerin
Application of the 3D-Printing and Commercial Off-The-Shelf Components in the Design of a Micro-Propulsion System
For the universities and private companies that have just been involved in the field of small satellites, it’s not easy to develop a propulsion system without special test equipment, rich experience and commercially available astronautics grade components, especially in the countries where the astronautic components sales market has not been fully developed.
Accordingly, a micro propulsion system for small satellites is being developed, which contains welded tanks, a 3Dprinted steam storage tank, heaters, solenoid valves and nozzles. HFC-134a is chosen to be the propellant because of its safety and accessibility. The steam storage tank and isolation solenoid valve nearby are used for pressure reducing, which avoids buying an astronautic grade pressure reducing valve from the market and make the propellant vaporized. Additive manufacturing is used to make special-shaped surfaces, reduce welding joints and the time of the steam storage tank production. In order to prevent the liquid propellant from entering the pipeline, the outlet of the propellant tank extends to the middle of the tank through a pipe. HFC-134a liquid will be infiltrated into aluminum alloy tank wall away from the outlet, which avoids the use of a Propellant Management Device (PMD).
A prototype of the system is being developed and tested. A simple thrust measurement method has been developed, and a large amount of experimental data has been obtained. The requirement, selection, design, prototype test and difficulties are reviewed in this paper, to provide a reference for the development of other propulsion systems
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β-Spectrin Regulates the Hippo Signaling Pathway and Modulates the Basal Actin Network
Emerging evidence suggests functional regulation of the Hippo pathway by the actin cytoskeleton, although the detailed molecular mechanism remains incomplete. In a genetic screen, we identified a requirement for -Spectrin in the posterior follicle cells for the oocyte repolarization process during Drosophila mid-oogenesis. -Spectrin mutations lead to loss of Hippo signaling activity in the follicle cells. A similar reduction of Hippo signaling activity was observed after -Spectrin knockdown in mammalian cells. We further demonstrated that -spectrin mutations disrupt the basal actin network in follicle cells. The abnormal stress fiber-like actin structure on the basal side of follicle cells provides a likely link between the -spectrin mutations and the loss of the Hippo signaling activity phenotype