117 research outputs found
Numerical study of stall inception in a transonic axial compressor rotor based on the throttle model
The goal of the current paper is to investigate inner flow behavior on stall inception in a transonic compressor rotor. The stall inception process is numerically carried out by unsteady 3-D simulations based on the throttle model. The current study shows that stall starts from the tip of the blade, and stall cell extends to the axial, circumferential and radial directions. Through the comparison of flow transition characteristics at different flow rate conditions, the interface between the incoming flow and tip clearance flow shifts forward to the upstream as the mass flow decreases. Eventually, the shock detaches from the blade leading edge, and tip clearance flow spills into the adjacent blade passage, thus stall happens in the affected blade passages
Hierarchical Catalogue Generation for Literature Review: A Benchmark
Multi-document scientific summarization can extract and organize important
information from an abundant collection of papers, arousing widespread
attention recently. However, existing efforts focus on producing lengthy
overviews lacking a clear and logical hierarchy. To alleviate this problem, we
present an atomic and challenging task named Hierarchical Catalogue Generation
for Literature Review (HiCatGLR), which aims to generate a hierarchical
catalogue for a review paper given various references. We carefully construct a
novel English Hierarchical Catalogues of Literature Reviews Dataset (HiCaD)
with 13.8k literature review catalogues and 120k reference papers, where we
benchmark diverse experiments via the end-to-end and pipeline methods. To
accurately assess the model performance, we design evaluation metrics for
similarity to ground truth from semantics and structure. Besides, our extensive
analyses verify the high quality of our dataset and the effectiveness of our
evaluation metrics. Furthermore, we discuss potential directions for this task
to motivate future research
Retracted: Safranal induces autophagy by AMPK activation and protects neurons against amyloid beta in Alzheimer’s disease
This article has been retracted by the authors
Genetic approach to track neural cell fate decisions using human embryonic stem cells
With their capability to undergo unlimited self-renewal and to differentiate into all cell types in the body, human embryonic stem cells (hESCs) hold great promise in human cell therapy. However, there are limited tools for easily identifying and isolating live hESC-derived cells. To track hESC-derived neural progenitor cells (NPCs), we applied homologous recombination to knock-in the mCherry gene into the Nestin locus of hESCs. This facilitated the genetic labeling of Nestin positive neural progenitor cells with mCherry. Our reporter system enables the visualization of neural induction from hESCs both in vitro (embryoid bodies) and in vivo (teratomas). This system also permits the identification of different neural subpopulations based on the intensity of our fluorescent reporter. In this context, a high level of mCherry expression showed enrichment for neural progenitors, while lower mCherry corresponded with more committed neural states. Combination of mCherry high expression with cell surface antigen staining enabled further enrichment of hESC-derived NPCs. These mCherry(+) NPCs could be expanded in culture and their differentiation resulted in a down-regulation of mCherry consistent with the loss of Nestin expression. Therefore, we have developed a fluorescent reporter system that can be used to trace neural differentiation events of hESCs
Two independent LAMP assays for rapid identification of the serpentine leafminer, Liriomyza huidobrensis (Blanchard, 1926) (Diptera: Agromyzidae) in Australia
Liriomyza huidobrensis is a leafminer fly and significant horticultural pest. It is a quarantine listed species in many countries and is now present as an established pest in Australia. Liriomyza huidobrensis uses a broad range of host plants and has potential for spread into various horticultural systems and regions of Australia. Rapid in-field identification of the pest is critically needed to assist efforts to manage this pest. Morphological identification of the pest is effectively limited to specialist examinations of adult males. Generally, molecular methods such as qPCR and DNA barcoding for identification of Liriomyza species require costly laboratory-based hardware. Herein, we developed two independent and rapid LAMP assays targeted to independently inherited mitochondrial and nuclear genes. Both assays are highly sensitive and specific to L. huidobrensis. Positive signals can be detected within 10 min on laboratory and portable real-time amplification fluorometers. Further, we adapted these assays for use with colorimetric master mixes, to allow fluorometer free in-field diagnostics of L. huidobrensis. Our LAMP assays can be used for stand-alone testing of query specimens and are likely to be essential tools used for rapid identification and monitoring of L. huidobrensis
Attempted Depletion of Passenger Leukocytes by Irradiation in Pigs
Allograft/xenograft rejection is associated with “passenger leukocyte” migration from the organ into recipient lymph nodes. In Study 1, we attempted to deplete leukocytes from potential kidney “donor” pigs, using two regimens of total body irradiation. A dose of 700 cGy was administered, followed by either 800 cGy (“low-dose”) or 1,300 cGy (“high dose”) with the kidneys shielded. Neither regimen was entirely successful in depleting all leukocytes, although remaining T and 8 cell numbers were negligible. Study 2 was aimed at providing an indication of whether near-complete depletion of leukocytes had any major impact on kidney allograft survival. In non-immunosuppressed recipient pigs, survival of a kidney from a donor that received high-dose irradiation was compared with that of a kidney taken from a non-irradiated donor. Kidney graft survival was 9 and 7 days, respectively, suggesting that depletion had little impact on graft survival. The lack of effect may have been related to (i) inadequate depletion of passenger leukocytes, thus not preventing a direct T cell response, (ii) the presence of dead or dying leukocytes (antigens), thus not preventing an indirect T cell response, or (iii) constitutive expression of MHC class II and B7 molecules on the porcine vascular endothelium, activating recipient T cells
Metabolic profiling and identification of shikonins in root periderm of two invasive Echium spp. weeds in Australia
Metabolic profiling can be successfully implemented to analyse a living system's response to environmental conditions by providing critical information on an organism's physiological state at a particular point in time and allowing for both quantitative and qualitative assessment of a specific subset(s) of key metabolites. Shikonins are highly reactive chemicals that affect various cell signalling pathways and possess antifungal, antibacterial and allelopathic activity. Based on previous bioassay results, bioactive shikonins, are likely to play important roles in the regulation of rhizosphere interactions with neighbouring plants, microbes and herbivores. An effective platform allowing for rapid identification and accurate profiling of numerous structurally similar, difficult-to-separate bioactive isohexenylnaphthazarins (shikonins) was developed using UHPLC Q-TOF MS. Root periderm tissues of the invasive Australian weeds Echium plantagineum and its congener E. vulgare were extracted overnight in ethanol for shikonin profiling. Shikonin production was evaluated at seedling, rosette and flowering stages. Five populations of each species were compared for qualitative and quantitative differences in shikonin formation. Each species showed little populational variation in qualitative shikonin production; however, shikonin was considerably low in one population of E. plantagineum from Western New South Wales. Seedlings of all populations produced the bioactive metabolite acetylshikonin and production was upregulated over time. Mature plants of both species produced significantly higher total levels of shikonins and isovalerylshikonin > dimethylacrylshikonin > shikonin > acetylshikonin in mature E. plantagineum. Although qualitative metabolic profiles in both Echium spp. were nearly identical, shikonin abundance in mature plant periderm was approximately 2.5 times higher in perennial E. vulgare extracts in comparison to those of the annual E. plantagineum. These findings contribute to our understanding of the biosynthesis of shikonins in roots of two related invasive plants and their expression in relation to plant phenological stage.This research was a part of the Australian Research Council project developed by and
granted to L.A.W., G.M.G. and R.M.C., D.
Basic Research on Rockburst Control Technology for Deep Well Filling of Municipal Solid Waste
AbstractGiven the scarcity of raw materials for rockburst prevention in filling mining and the lack of space for disposal of large amount of municipal waste, the feasibility of preparing filling materials for rockburst mines from stale waste was investigated by laboratory tests and theoretical analysis. On this basis, the process of preparing filling materials from stale garbage was proposed, and corresponding equipment were developed to prepare stale garbage filling mass. According to the characteristics and uses of the stale waste filling materials, two processes of volume filling and strength filling are proposed, and the key technology of stale garbage filling to control rockburst was designed. The following conclusions were drawn: stale garbage can be made into mine filling material because of its composition, strength, and shape. The process of preparing mine filling materials from obsolete waste includes crushing, screening, compression, and packaging. The equipment suitable for the process includes crushing-screening, compression-forming, and sealing-packaging integrated equipment. The equipment has realized effective screening, compression, and bulk packaging of stale garbage, so that the stale garbage filling mass can meet the requirements of environmental protection and strength. Strength filling is a filling method that uses the strength of stale garbage filling mass to protect the overlying strata from or less damage, thereby reducing the stress concentration in the coal face and reducing the risk of rockburst occurring. Volume filling mainly depends on the volume of the filling mass, with the main purpose of reducing the stress concentration in the roadway surrounding rock. The rockburst mine filling technology of stale garbage is support track filling technology and bag filling technology, and the deep well sealing of stale garbage is block stacking technology. The deep well filling mining key technologies provide a new approach to against rockburst and treat large amounts of municipal waste
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