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Speech emotion recognition (SER) plays an important role in real-time applications of human-machine interaction. The Attention Mechanism is widely used to improve the performance of SER. However, the applicable rules of attention mechanism are not deeply discussed. This paper discussed the difference between Global-Attention and Self-Attention and explored their applicable rules to SER classification construction. The experimental results show that the Global-Attention can improve the accuracy of the sequential model, while the Self-Attention can improve the accuracy of the parallel model when conducting the model with the CNN and the LSTM. With this knowledge, a classifier (CNN-LSTM×2+Global-Attention model) for SER is proposed. The experiments result show that it could achieve an accuracy of 85.427% on the EMO-DB dataset.

Collaborative states recognition is a critical issue for human-robot collaboration during contact task. This paper proposed a flexible contact dynamics and feature selection based state recognition method to identify human-robot collaborative grinding state. The core issue for collaborative grinding states recognition is to distinguish human-robot contact from robot-environment contact. To achieve this, contact dynamic models of both contacts are first constructed to identify the dynamics difference between human-robot contact and robot-environment contact. Considering the reaction speed required by human-robot collaborative states recognition, feature selection based on Spearman correlation and random forest recursive feature elimination are conducted to reduce data redundancy and computation burden. Long short term memory(LSTM) is then used to construct a collaborative states classifier. Experiments results illustrate that the proposed method can achieve a 96% recognition accuracy in a period of 5ms and 99% in a period of 40ms.

The development of the medicinal tea (MT) system has promoted the health awareness in the whole world, and the nutritional elements are also an important resource of health care delivery except for the medicinal components. Among various medicinal teas, Astragalus membranaceus (AM), Zingiberaceae rhizome (ZR), and Lonicera japonica (LJ) were the most popular ingredients in China. However, except for the nutrition value, MT was inevitably contaminated with heavy metals due to the special planting environment and processing system. This study was aimed to investigate the distribution characteristics of nutrition elements and combined health risk of heavy metals in MT sample, referring to the maximum residue limit (MRL), estimated daily intake (EDI), total target hazard quotients (TTHQs), and lifetime cancer risk (LCR). Furthermore, the bioaccessibility of gastrointestinal phase and bioavailability of human colon adeno carcinoma cell line were selected for elaborating the exact damage degree to human digestive system. The results showed that, the nutritional elements of Na, Se, K, Ca, and Mn were very rich in MT, but a total of 50% of MT were contaminated by Cr, Hg, and Cd in raw material. Although the cumulative lifetime cancer risk can be accepted under the bioaccessibility (26.62–99.27%), the heavy metals of Cr, As, Hg, and Fe in AM and LJ posed a slight threaten of non-carcinogenic risk to consumers. This study will give an exactly assessment of multiple elements in digestive system, thus further to predict the potential health risk under the consumption of MT products.

The endogenous peptides AtPepl-8 in Arabidopsis mature from the conserved C-terminal portions of their precursor proteins PROPEP1-8, respectively. The two homologous leucine-rich repeat-receptor kinases （LRR-RKs） PEPR1 and PEPR2 act as receptors of AtPeps. AtPep binding leads to stable association of PEPR1,2 with the shared receptor LRR-RK BAK1, eliciting immune responses similar to those induced by pathogens. Here we report a crystal structure of the extraceUular LRR domain of PEPRI （PEPR1LRR） in complex with AtPepl. The structure reveals that AtPepl adopts a fully extended conformation and binds to the inner surface of the superhelical PEPRILRR. Biochemical assays showed that AtPepl is capable of inducing PEPR1LRR-BAK1LRR heterodimerization. The conserved C-terminal portion of AtPepl dominates AtPepl binding to PEPRILRR, with the last amino acid of AtPepl Asn23 forming extensive interactions with PEPR1LRR. Deletion of the last residue of AtPepl significantly compromised AtPep1 interaction with PEPRILRR. Together, our data reveal a conserved structural mechanism of AtPep1 recognition by PEPR1, providing significant insight into prediction of recognition of other peptides by their cognate LRR-RKs.

The divergence of archaea, bacteria and eukaryotes was a fundamental step in evolution. One marker of this event is a major difference in membrane lipid chemistry between these kingdoms. Whereas the membranes of bac- teria and eukaryotes primarily consist of straight fatty acids ester-bonded to glycerol-3-phosphate, archaeal phos- pholipids consist of isoprenoid chains ether-bonded to glycerol-l-phosphate. Notably, the mechanisms underlying the biosynthesis of these lipids remain elusive. Here, we report the structure of the CDP-archaeol synthase （CarS） of Aeropyrum pernix （ApCarS） in the CTP- and Mg2＋-bound state at a resolution of 2.4 A.. The enzyme comprises a transmembrane domain with five helices and cytoplasmic loops that together form a large charged cavity providing a binding site for CTP. Identification of the binding location of CTP and Mg2＋ enabled modeling of the specific lipophil- ie substrate-binding site, which was supported by site-directed mutagenesis, substrate-binding affinity analyses, and enzyme assays. We propose that archaeol binds within two hydrophobic membrane-embedded grooves formed by the flexible transmembrane helix 5 （TM5）, together with TM1 and TM4. Collectively, structural comparisons and analyses, combined with functional studies, not only elucidated the mechanism governing the biosynthesis of pbospholipids with ether-bonded isoprenoid chains by CTP transferase, but also provided insights into the evolution of this enzyme superfamily from archaea to bacteria and eukaryotes.

Biologists long recognized that the genetic information encoded in DNA leads to trait innovation via gene regulatory network (GRN) in development. Here, we generated paired expression and chromatin accessibility data during rumen and esophagus development in sheep and revealed 1,601 active ruminant-specific conserved non-coding elements (active-RSCNEs). To interpret the function of these active-RSCNEs, we developed a Conserved Non-coding Element interpretation method by gene Regulatory network (CNEReg) to define toolkit transcription factors (TTF) and model its regulation on rumen specific gene via batteries of active-RSCNEs during development. Our developmental GRN reveals 18 TTFs and 313 active-RSCNEs regulating the functional modules of the rumen and identifies OTX1, SOX21, HOXC8, SOX2, TP63, PPARG and 16 active-RSCNEs that functionally distinguish the rumen from the esophagus. We argue that CNEReg is an attractive systematic approach to integrate evo-devo concepts with omics data to understand how gene regulation evolves and shapes complex traits.

Expansion microscopy (ExM) allows super-resolution imaging on conventional fluorescence microscopes, but has been limited to proteins and nucleic acids. Here we develop click-ExM, which integrates click labeling into ExM to enable a ‘one-stop-shop’ method for nanoscale imaging of various types of biomolecule. By click labeling with biotin and staining with fluorescently labeled streptavidin, a large range of biomolecules can be imaged by the standard ExM procedure normally used for proteins. Using 18 clickable labels, we demonstrate click-ExM on lipids, glycans, proteins, DNA, RNA and small molecules. We demonstrate that click-ExM is applicable in cell culture systems and for tissue imaging. We further show that click-ExM is compatible with signal-amplification techniques and two-color imaging. Click-ExM thus provides a convenient and versatile method for super-resolution imaging, which may be routinely used for cell and tissue samples.Click-ExM uses click-chemistry-based labeling to increase the versatility of expansion microscopy. Click-ExM enables imaging of numerous classes of biomolecules including lipids, glycans, proteins, DNA, RNA and small molecules.

Glucose transporters are essential for metabolism of glucose in cells of diverse organisms from microbes to humans, exemplified by the disease-related human proteins GLUT1, 2, 3 and 4. Despite rigorous efforts, the structural information for GLUT1–4 or their homologues remains largely unknown. Here we report three related crystal structures of XylE, an Escherichia coli homologue of GLUT1–4, in complex with d -xylose, d -glucose and 6-bromo-6-deoxy- d -glucose, at resolutions of 2.8, 2.9 and 2.6 Å, respectively. The structure consists of a typical major facilitator superfamily fold of 12 transmembrane segments and a unique intracellular four-helix domain. XylE was captured in an outward-facing, partly occluded conformation. Most of the important amino acids responsible for recognition of d -xylose or d -glucose are invariant in GLUT1–4, suggesting functional and mechanistic conservations. Structure-based modelling of GLUT1–4 allows mapping and interpretation of disease-related mutations. The structural and biochemical information reported here constitutes an important framework for mechanistic understanding of glucose transporters and sugar porters in general. A study of X-ray crystal structures of the Escherichia coli xylose transporter XylE, which is a bacterial homologue of the human glucose transporters GLUT1–4, complexed with glucose and its analogues yields a framework for understanding the molecular mechanism by which membrane proteins transport glucose and other sugars across cell membranes. Glucose transporter structure determined Proteins that transport glucose across cellular membranes are essential for glucose metabolism in many organisms, from microbes to mammals. This Article reports three X-ray crystal structures of XylE — an Escherichia coli homologue of the GLUT family of human proteins — in complex with D -xylose, D -glucose and 6-bromo-6-deoxy- D -glucose. Structure-based modelling of GLUT1–4 enabled the authors to map known disease-related mutations, and the structural and biochemical information reported here provides a framework for understanding the molecular mechanism by which membrane proteins transport glucose and other sugars.

Unnatural monosaccharides such as azidosugars that can be metabolically incorporated into cellular glycans are currently used as a major tool for glycan imaging and glycoproteomic profiling. As a common practice to enhance membrane permeability and cellular uptake, the unnatural sugars are per- O -acetylated, which, however, can induce a long-overlooked side reaction, non-enzymatic S-glycosylation. Herein, we develop 1,3-di-esterified N -azidoacetylgalactosamine (GalNAz) as next-generation chemical reporters for metabolic glycan labeling. Both 1,3-di- O -acetylated GalNAz (1,3-Ac 2 GalNAz) and 1,3-di- O -propionylated GalNAz (1,3-Pr 2 GalNAz) exhibit high efficiency for labeling protein O-GlcNAcylation with no artificial S-glycosylation. Applying 1,3-Pr 2 GalNAz in mouse embryonic stem cells (mESCs), we identify ESRRB, a critical transcription factor for pluripotency, as an O-GlcNAcylated protein. We show that ESRRB O-GlcNAcylation is important for mESC self-renewal and pluripotency. Mechanistically, ESRRB is O-GlcNAcylated by O-GlcNAc transferase at serine 25, which stabilizes ESRRB, promotes its transcription activity and facilitates its interactions with two master pluripotency regulators, OCT4 and NANOG. Per- O -acetylated unnatural monosaccharides are popular tools for glycan labeling in live cells but can undergo unwanted side reactions with cysteines. Here, the authors develop unnatural sugars in a partially esterified form that are inert towards cysteines, and use them to probe O-GlcNAcylation in mESCs.

The development of high-performance metal-free organic X-ray scintillators (OXSTs), characterized by a synergistic combination of robust X-ray absorption, efficient exciton utilization, and short luminescence lifetimes, poses a considerable challenge. Here we present an effective strategy for achieving augmented X-ray scintillation through the utilization of halogenated open-shell organic radical scintillators. Our experimental results demonstrate that the synthesized scintillators exhibit strong X-ray absorption derived from halogen atoms, display efficacious X-ray stability, and theoretically achieve 100% exciton utilization efficiency with a short lifetime (∼18 ns) due to spin-allowed doublet transitions. The superior X-ray scintillation performance exhibited by these organic radicals is not only exploitable in X-ray radiography for contrast imaging of various objects but also applicable in a medical high-resolution micro-computer-tomography system for the clear visualization of fibrous veins within a bamboo stick. Our study substantiates the promise of organic radicals as prospective candidates for OXSTs, offering valuable insights and a roadmap for the development of advanced organic radical scintillators geared towards achieving high-quality X-ray radiography. The development of metal-free organic X-ray scintillators combining X-ray absorption, efficient exciton utilization, and short luminescence lifetimes, remains challenging. Here, the authors present a strategy for achieving augmented X-ray scintillation through the utilization of halogenated open-shell organic radical scintillators.