159 research outputs found
CMAS-resistance of a yttria graded thermal barrier coating fabricated by plasma activated EB-PVD
EB-PVD yttria stabilized zirconia (YSZ) thermal barrier coatings (TBCs) are susceptible to calcia-magnesia-aluminum-silicate (CMAS) corrosion. The service lifetime of typical 8YSZ TBCs can be significantly reduced by CMAS attack. Currently, composition and microstructure modifications are the most commonly used methods for CMAS infiltration resistance. It has been reported by previous researchers that reactive elements, including Y, Gd, La, and etc., doped in TBCs can promote the formation of a dense protective layer by a sacrificing reaction with CMAS. It is therefore that the CMAS infiltration can be retarded. Besides, tailored columnar grains of TBCs are are also proved to be effective for CMAS mitigation.
In this work, TBCs specimens with graded microstructure were fabricated by EB-PVD. The upper region of the TBC was doped with a higher Y2O3 content up to 25 wt.%, compared with the conventional 8YSZ composition. Besides, plasma activation was also introduced in the EB-PVD process to yield a tailored coating morphology and prosity. The coating specimens were tested at 1250 oC for evaluating CMAS resistance. Conventional YSZ coatings and graded coatings without plasma activation were also investigated for comparison
Towards Runtime Customizable Trusted Execution Environment on FPGA-SoC
Processing sensitive data and deploying well-designed Intellectual Property
(IP) cores on remote Field Programmable Gate Array (FPGA) are prone to private
data leakage and IP theft. One effective solution is constructing Trusted
Execution Environment (TEE) on FPGA-SoCs (FPGA System on Chips). Researchers
have integrated this type TEE with Trusted Platform Module (TPM)-based trusted
boot, denoted as FPGA-SoC tbTEE. But there is no effort on secure and trusted
runtime customization of FPGA-SoC TEE. This paper extends FPGA-SoC tbTEE to
build Runtime Customizable TEE (RCTEE) on FPGA-SoC by additive three major
components (our work): 1) CrloadIP, which can load an IP core at runtime such
that RCTEE can be adjusted dynamically and securely; 2) CexecIP, which can not
only execute an IP core without modifying the operating system of FPGA-SoC TEE,
but also prevent insider attacks from executing IPs deployed in RCTEE; 3)
CremoAT, which can provide the newly measured RCTEE state and establish a
secure and trusted communication path between remote verifiers and RCTEE. We
conduct a security analysis of RCTEE and its performance evaluation on Xilinx
Zynq UltraScale+ XCZU15EG 2FFVB1156 MPSoC
Continual All-in-One Adverse Weather Removal with Knowledge Replay on a Unified Network Structure
In real-world applications, image degeneration caused by adverse weather is
always complex and changes with different weather conditions from days and
seasons. Systems in real-world environments constantly encounter adverse
weather conditions that are not previously observed. Therefore, it practically
requires adverse weather removal models to continually learn from incrementally
collected data reflecting various degeneration types. Existing adverse weather
removal approaches, for either single or multiple adverse weathers, are mainly
designed for a static learning paradigm, which assumes that the data of all
types of degenerations to handle can be finely collected at one time before a
single-phase learning process. They thus cannot directly handle the incremental
learning requirements. To address this issue, we made the earliest effort to
investigate the continual all-in-one adverse weather removal task, in a setting
closer to real-world applications. Specifically, we develop a novel continual
learning framework with effective knowledge replay (KR) on a unified network
structure. Equipped with a principal component projection and an effective
knowledge distillation mechanism, the proposed KR techniques are tailored for
the all-in-one weather removal task. It considers the characteristics of the
image restoration task with multiple degenerations in continual learning, and
the knowledge for different degenerations can be shared and accumulated in the
unified network structure. Extensive experimental results demonstrate the
effectiveness of the proposed method to deal with this challenging task, which
performs competitively to existing dedicated or joint training image
restoration methods. Our code is available at
https://github.com/xiaojihh/CL_all-in-one
Vascular niche IL-6 induces alternative macrophage activation in glioblastoma through HIF-2α.
Spatiotemporal regulation of tumor immunity remains largely unexplored. Here we identify a vascular niche that controls alternative macrophage activation in glioblastoma (GBM). We show that tumor-promoting macrophages are spatially proximate to GBM-associated endothelial cells (ECs), permissive for angiocrine-induced macrophage polarization. We identify ECs as one of the major sources for interleukin-6 (IL-6) expression in GBM microenvironment. Furthermore, we reveal that colony-stimulating factor-1 and angiocrine IL-6 induce robust arginase-1 expression and macrophage alternative activation, mediated through peroxisome proliferator-activated receptor-γ-dependent transcriptional activation of hypoxia-inducible factor-2α. Finally, utilizing a genetic murine GBM model, we show that EC-specific knockout of IL-6 inhibits macrophage alternative activation and improves survival in the GBM-bearing mice. These findings illustrate a vascular niche-dependent mechanism for alternative macrophage activation and cancer progression, and suggest that targeting endothelial IL-6 may offer a selective and efficient therapeutic strategy for GBM, and possibly other solid malignant tumors
Effects of short-term grazing prohibition on soil physical and chemical properties of meadows in Southwest China
Background Grassland plays an important role in the ecosystem, but overgrazing harms the grassland system in many places. Grazing prohibition is an effective method to restore grassland ecosystems, and it plays a great role in realizing the sustainable development of grassland systems. Therefore, it is necessary to carry out research on the influence of regional grazing prohibition on the physical and chemical properties of different grassland systems. Methods In Potatso National Park, Southwest China, we selected experimental plots in the artificial grazing meadow area to study the effects of grazing prohibition on plant and soil indexes in subalpine meadows and swamp meadows. We investigated the biomass and species diversity of grazing prohibition treatment and grazing treatment plots and sampled and tested the soil index. The variation percentage was used to remove the original heterogeneity and yearly variation, allowing us to compare differences in plant index and soil index values between grazing prohibition and grazing treatments. Results Grazing prohibition increased the aboveground biomass, total biomass, total meadow coverage, average height, richness index, Shannon diversity index and evenness index and reduced the belowground biomass and root/shoot ratio in the subalpine meadow and swamp meadow. Additionally, grazing prohibition reduced the pH and soil bulk density and increased the soil total carbon, soil organic carbon, soil total nitrogen, soil hydrolyzable nitrogen, soil total phosphorus and soil available phosphorus in the subalpine meadow and swamp meadow. Nonmetric multidimensional scaling (NMDS) analysis showed that both plant indexes and soil indexes were significantly different between grazing and grazing prohibition treatments and between meadow types. Short-term grazing prohibition had a great impact on improving the fertility of meadow soil in the study area. We suggest that long-term and extensive research should be carried out to promote the restoration and sustainable development of regional grassland systems
Arcuate Nucleus Orexin-A Signaling Alleviates Cisplatin-Induced Nausea and Vomiting Through the Paraventricular Nucleus of the Hypothalamus in Rats
The most common side effects of cisplatin chemotherapy are nausea and vomiting, and the overwhelming majority of research studies on the mechanism of cisplatin-induced nausea have been focused on the “vomiting center.” As a modulatory center of gastric motility, the roles of the hypothalamus in nausea and vomiting remain unclear. In the present study, we investigated the effects of exogenous orexin-A injected into the arcuate nucleus (ARC) on cisplatin-induced nausea and vomiting, and the possible underlying mechanism. Kaolin intake was calculated daily in cisplatin-treated and saline-treated rats. Gastric motility recording, injections into the ARC, and lesions of the paraventricular nucleus (PVN) were used to study the effects of orexin-A and the hypothalamic nucleus on disorders of gastrointestinal function in cisplatin-treated rats. The pathway from the ARC to the PVN was observed through Fluoro-Gold retrograde tracing. Furthermore, an NPY Y1 receptor antagonist was administered to explore the possible mechanisms involved in the effects of orexin-A in the ARC. We illustrated that exogenous orexin-A injected into the ARC reduced kaolin intake and promoted gastric motility in cisplatin-treated rats, and these effects could have been blocked by an ipsilateral PVN lesion or co-injected antagonist of orexin-A-SB334867. Additional results showed that orexin-A-activated neurons in the ARC communicated directly with other neurons in the PVN that express neuropeptide Y (NPY). Furthermore, activation of the downstream NPY pathway was required for the observed effects of orexin in the ARC on cisplatin-induced nausea and vomiting. These findings reveal a novel neurobiological circuit from the ARC to the PVN that might provide a potential target for the prevention and treatment of cisplatin-induced nausea and vomiting
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