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Establishing the host range for novel viruses remains a challenge. Here, we address the challenge of identifying non-human animal coronaviruses that may infect humans by creating an artificial neural network model that learns from spike protein sequences of alpha and beta coronaviruses and their binding annotation to their host receptor. The proposed method produces a human-Binding Potential (h-BiP) score that distinguishes, with high accuracy, the binding potential among coronaviruses. Three viruses, previously unknown to bind human receptors, were identified: Bat coronavirus BtCoV/133/2005 and Pipistrellus abramus bat coronavirus HKU5-related (both MERS related viruses), and Rhinolophus affinis coronavirus isolate LYRa3 (a SARS related virus). We further analyze the binding properties of BtCoV/133/2005 and LYRa3 using molecular dynamics. To test whether this model can be used for surveillance of novel coronaviruses, we re-trained the model on a set that excludes SARS-CoV-2 and all viral sequences released after the SARS-CoV-2 was published. The results predict the binding of SARS-CoV-2 with a human receptor, indicating that machine learning methods are an excellent tool for the prediction of host expansion events.

The visual system has a strong information processing ability, and visual attention tracking has various applications in various scenes. This paper mainly focuses on the sports scene of ice and snow far mobilization. It constructs a visual attention system model based on eye tracking. It first establishes an eye tracking system framework using deep learning, and improves the gaze estimation by optimizing the feature extraction network. The visual attention system model was constructed using particle filtering based on motion feature cognition. In the eye-tracking visual attention system model experiments, the Accuracy of the improved eye-tracking system in this paper can be significantly improved to 1.13°, and the error of the visual attention system can be kept within 10°. Furthermore, the four ice and snow sports scene types have an average accuracy of 85.47%, and the constructed model performs well. This study offers a guide for effectively combining eye tracking technology and visual attention.

Background & aimsThe β-catenin signaling pathway is one of the most commonly deregulated pathways in cancer cells. Amino acid substitutions within armadillo repeats 5 and 6 (K335, W383, and N387) of β-catenin are found in several tumor types, including liver tumors. We investigated the mechanisms by which these substitutions increase signaling and the effects on liver carcinogenesis in mice.MethodsPlasmids encoding tagged full-length β-catenin (CTNNB1) or β-catenin with the K335I or N387K substitutions, along with MET, were injected into tails of FVB/N mice. Tumor growth was monitored, and livers were collected and analyzed by histology, immunohistochemistry, and quantitative reverse-transcription polymerase chain reaction. Tagged full-length and mutant forms of β-catenin were expressed in HEK293, HCT116, and SNU449 cells, which were analyzed by immunoblots and immunoprecipitation. A panel of β-catenin variants and cell lines with knock-in mutations were analyzed for differences in N-terminal phosphorylation, half-life, and association with other proteins in the signaling pathway.ResultsMice injected with plasmids encoding K335I or N387K β-catenin and MET developed larger, more advanced tumors than mice injected with plasmids encoding WT β-catenin and MET. K335I and N387K β-catenin bound APC with lower affinity than WT β-catenin but still interacted with scaffold protein AXIN1 and in the nucleus with TCF7L2. This interaction resulted in increased transcription of genes regulated by β-catenin. Studies of protein structures supported the observed changes in relative binding affinities.ConclusionExpression of β-catenin with mutations in armadillo repeats 5 and 6, along with MET, promotes formation of liver tumors in mice. In contrast to N-terminal mutations in β-catenin that directly impair its phosphorylation by GSK3 or binding to BTRC, the K335I or N387K substitutions increase signaling via reduced binding to APC. However, these mutant forms of β-catenin still interact with the TCF family of transcription factors in the nucleus. These findings show how these amino acid substitutions increase β-catenin signaling in cancer cells.

We report results from 8 h of JWST /MIRI low resolution spectroscopic (LRS) monitoring directly followed by 7 h of JWST /NIRSpec prism spectroscopic monitoring of the benchmark binary brown dwarf WISE 1049AB, the closest, brightest brown dwarfs known. We find water, methane, and CO absorption features in both components, including the 3.3  μ m methane absorption feature and a tentative detection of small grain (⁠|$\lt $| 1 μ m) silicate absorption at |$\gt $| 8.5 μ m in WISE 1049A. Both components vary significantly (⁠|$\gt 1~{{\rm per\ cent}}$|⁠), with WISE 1049B displaying larger variations than WISE 1049A. Using K -means clustering, we find three main transition points in wavelength for both components of the binary: (1) change in behaviour at |$\sim$| 2.3 μ m coincident with a CO absorption bandhead, (2) change in behaviour at 4.2 μ m, close to the CO fundamental band at |$\lambda \gt $|  4.4 µm, and (3) change in behaviour at 8.3–8.5 µm, potentially corresponding to silicate absorption. We interpret the light curves observed with both NIRSpec and MIRI as likely stemming from (1) a deep pressure level driving the double-peaked variability seen in WISE 1049B at wavelengths |$\lt $| 2.3 and |$\gt $| 8.5 µm, (2) an intermediate pressure level shaping the light-curve morphology between 2.3 and 4.2 µm, and (3) a higher altitude pressure level producing single-peaked and plateaued light-curve behaviour between 4.2 and 8.5 µm. [ABSTRACT FROM AUTHOR]

Chitosan is a naturally-occurring alkaline polysaccharide with excellent biocompatibility, biodegradability, low toxicity, and easy preparation. It has been widely used in the construction of delivery systems for various nutrients and bioactive substances. The chitosan-based nutrient delivery systems are mainly constructed by cross-linking, drying, layer-by-layer self-assembly, coalescence, covalent grafting, microfluidics and biosynthesis. Chitosan can be combined with carbohydrates, proteins and liposomes to form a composite carrier that can obtain more excellent performance and broaden its application in food packaging materials, slow release of bioactive substances and probiotic embedding. In addition, this paper further analyzes the obstacles and limitations of the actual application of chitosan-based nutrient delivery systems in the food industry, to provide important references for the application of chitosan-based delivery carriers in imparting new functional properties to foods, developing new food ingredients, and nutrient fortification. [ABSTRACT FROM AUTHOR]

Solution‐processed 2D materials hold promise for their scalable applications. However, the random, fragmented nature of the solution‐processed nanoflakes and the poor percolative conduction through their discrete networks limit the performance of the enabled devices. To overcome the problem, conduction modulation of the solution‐processed 2D materials is reported via Stark effect. Using liquid‐phase exfoliated molybdenum disulfide (MoS2) as an example, nonlinear conduction switching with a ratio of >105 is demonstrated by the local fields from the interfacial ferroelectric P(VDF‐TrFE). Through density‐functional theory calculations and in situ Raman scattering and photoluminescence spectroscopic analysis, the modulation is understood to arise from a charge redistribution in the solution‐processed MoS2. Beyond MoS2, the modulation may be shown effective for the other solution‐processed 2D materials and low‐dimensional materials. The modulation can open their electronic device applications, for instance, thin‐film nonlinear electronics and non‐volatile memories. [ABSTRACT FROM AUTHOR]