133 research outputs found
The mushroom, Cordyceps cicadae, ameliorates renal interstitial fibrosis via TLR2-mediated pathways
Purpose: To evaluate the mushroom, Cordyceps cicadae, for its ability to suppress tissue fibrosis and Toll-like receptors 2 (TLR 2) pathway activation in a mouse model of renal interstitial fibrosis (RIF).Methods: Cordyceps cicadae powder was obtained from BioAsia Group (Shanghai, China). RIF was induced via unilateral ureteral obstruction (UUO) in male C57Bl/6 mice. Animals were treated via the intragastric administration of Cordyceps cicadae powder (0.1g, 0.3 g/ml/100 g/day), beginning 24 h prior to UUO, and the treatment was continued for the following 14 days. Changes in tissue histology were then assessed via hematoxylin and eosin, and Sirius red stainings. Tissue macrophages were characterized based upon their expression of inducible nitric oxide synthase (iNOS) and interleukin-10 (IL-10), while Western blotting technique was used to measure the levels of TLR2, Myeloid differentiation factor 88 (MyD88), and nuclear factor-κB (NF-κB)/p-NF-κB in samples from these animals.Results: Treatment with Cordyceps cicadae powder is associated with a shift in macrophage phenotype that in turn decreased the production of extracellular matrix and alleviated RIF occurrence in mice model.Conclusion: This mechanistic study highlights the novel potential approach for treating and preventing RIF using Cordyceps cicadae powder.
Keywords: Renal interstitial fibrosis, TLR2-mediated pathway, Cordyceps cicada
Exploiting Spatial Sparsity for Event Cameras with Visual Transformers
Event cameras report local changes of brightness through an asynchronous
stream of output events. Events are spatially sparse at pixel locations with
little brightness variation. We propose using a visual transformer (ViT)
architecture to leverage its ability to process a variable-length input. The
input to the ViT consists of events that are accumulated into time bins and
spatially separated into non-overlapping sub-regions called patches. Patches
are selected when the number of nonzero pixel locations within a sub-region is
above a threshold. We show that by fine-tuning a ViT model on the selected
active patches, we can reduce the average number of patches fed into the
backbone during the inference by at least 50% with only a minor drop (0.34%) of
the classification accuracy on the N-Caltech101 dataset. This reduction
translates into a decrease of 51% in Multiply-Accumulate (MAC) operations and
an increase of 46% in the inference speed using a server CPU
T-NGA: Temporal Network Grafting Algorithm for Learning to Process Spiking Audio Sensor Events
Spiking silicon cochlea sensors encode sound as an asynchronous stream of
spikes from different frequency channels. The lack of labeled training datasets
for spiking cochleas makes it difficult to train deep neural networks on the
outputs of these sensors. This work proposes a self-supervised method called
Temporal Network Grafting Algorithm (T-NGA), which grafts a recurrent network
pretrained on spectrogram features so that the network works with the cochlea
event features. T-NGA training requires only temporally aligned audio
spectrograms and event features. Our experiments show that the accuracy of the
grafted network was similar to the accuracy of a supervised network trained
from scratch on a speech recognition task using events from a software spiking
cochlea model. Despite the circuit non-idealities of the spiking silicon
cochlea, the grafted network accuracy on the silicon cochlea spike recordings
was only about 5% lower than the supervised network accuracy using the
N-TIDIGITS18 dataset. T-NGA can train networks to process spiking audio sensor
events in the absence of large labeled spike datasets.Comment: 5 pages, 4 figures; accepted at IEEE International Conference on
Acoustics, Speech and Signal Processing (ICASSP), Singapore, 202
Using Statistical Analysis to Examine Weather Variability in New York City
As the overall temperature of Earth continues to warm, atmospheric hazards (e.g. heatwaves, cyclones) may be driving increases in climatological trends. This study examines the daily precipitation and temperature record of the greater New York City region during the 1979-2014 period. Daily station observations from three greater New York City airports: John F. Kennedy (JFK), LaGuardia (LGA) and Newark (EWR), are used in this study. Climatological & statistical analyses are performed for the weather variability of New York City metro area to understand the impacts of climate change.The temperature climatology reveals a distinct seasonal cycle, while the precipitation climatology exhibits greater day-to-day variability. Furthermore, annual mean of precipitation and temperature in New York City show increasing trends with temperature trend is significant. After that, this study compare to other research findings with a different region such as Amazon Basin to examine climatological pattern of precipitation in both daily and annual climatological trend. Amazon basin has different climate phenomena than New York City due to different geographical location. Daily Climatology of precipitation in Amazon basin shows the greatest intensity occurred in January to March, with minimum in July. The annual mean of precipitation match with our spatial result generated by GPCP for global precipitation mean for January and July
Selective filling of n-hexane in a tight nanopore
Partial funding for Open Access provided by the UMD Libraries' Open Access Publishing Fund.Molecular sieving may occur when two molecules compete for a nanopore. In nearly all known examples, the nanopore is larger than the molecule that selectively enters the pore. Here, we experimentally demonstrate the ability of single-wall carbon nanotubes with a van der Waals pore size of 0.42 nm to separate n-hexane from cyclohexane—despite the fact that both molecules have kinetic diameters larger than the rigid nanopore. This unexpected finding challenges our current understanding of nanopore selectivity and how molecules may enter a tight channel. Ab initio molecular dynamics simulations reveal that n-hexane molecules stretch by nearly 11.2% inside the nanotube pore. Although at a relatively low probability (28.5% overall), the stretched state of n-hexane does exist in the bulk solution, allowing the molecule to enter the tight pore even at room temperature. These insights open up opportunities to engineer nanopore selectivity based on the molecular degrees of freedom.https://doi.org/10.1038/s41467-020-20587-
Preparation of Decachlorocorannulene and Other Perchlorinated Fragments of Fullerenes by Electrical Discharge in Liquid Chloroform
地址:
1. XIAMEN UNIV, DEPT CHEM, STATE KEY LAB PHYS CHEM SOLID SURFACE, XIAMEN 361005, FUJIAN PEOPLES R CHIN
Novel Yersinia enterocolitica Prophages and a Comparative Analysis of Genomic Diversity
Yersinia enterocolitica is a major agent of foodborne diseases worldwide. Prophage plays an important role in the genetic evolution of the bacterial genome. Little is known about the genetic information about prophages in the genome of Y. enterocolitica, and no pathogenic Y. enterocolitica prophages have been described. In this study, we induced and described the genomes of six prophages from pathogenic Y. enterocolitica for the first time. Phylogenetic analysis based on whole genome sequencing revealed that these novel Yersinia phages are genetically distinct from the previously reported phages, showing considerable genetic diversity. Interestingly, the prophages induced from O:3 and O:9 Y. enterocolitica showed different genomic sequences and morphology but highly conserved among the same serotype strains, which classified into two diverse clusters. The three long-tailed Myoviridae prophages induced from serotype O:3 Y. enterocolitica were highly conserved, shared ≥99.99% identity and forming genotypic cluster A; the three Podoviridae prophages induced from the serotype O:9 strains formed cluster B, also shared more than 99.90% identity with one another. Cluster A was most closely related to O:5 non-pathogenic Y. enterocolitica prophage PY54 (61.72% identity). The genetic polymorphism of these two kinds of prophages and highly conserved among the same serotype strains, suggested a possible shared evolutionary past for these phages: originated from distinct ancestors, and entered pathogenic Y. enterocolitica as extrachromosomal genetic components during evolution when facing selective pressure. These results are critically important for further understanding of phage roles in host physiology and the pathology of disease
Macroscopic Neat Single-Walled Carbon Nanotubes Fibers
The first-ever well-aligned continuous macroscopic neat single-walled carbon nanotube (SWNT) fibers were produced using conventional spinning techniques. Neat SWNT fibers, containing no surfactant or polymer, were made by spinning dispersions of SWNTs in 102% sulfuric acid into different coagulants. The critical role of sulfuric acid in dispersing and aligning SWNTs during fiber formation has been explored. Characterization shows alignment greater than any other macroscopic neat SWNT material reported to-date while providing insight into the fundamental hierarchy and nature of SWNT fiber formation. Electrical, thermal, and mechanical measurements indicate that neat SWNT fibers hold tremendous potential for future applications
Diameter-dependent, progressive alkylcarboxylation of single-walled carbon nanotubes
We demonstrate diameter-dependent, progressive alkylcarboxylation of single-walled carbon nanotubes by recycling a modified Billups-Birch reaction. The strong diameter dependence was confirmed by Raman spectroscopy. Alkylcarboxylation made SWNTs soluble in water, allowing the more readily functionalized, smaller diameter nanotubes to be enriched by water extraction.University of Maryland; ACS; Maryland Department of Business and Economic Development; State Scholarship Council of China; Department of Energy Office; FPNSFC[2009J05034
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