Learning to Use Chopsticks in Diverse Gripping Styles

Learning dexterous manipulation skills is a long-standing challenge in computer graphics and robotics, especially when the task involves complex and delicate interactions between the hands, tools and objects. In this paper, we focus on chopsticks-based object relocation tasks, which are common yet demanding. The key to successful chopsticks skills is steady gripping of the sticks that also supports delicate maneuvers. We automatically discover physically valid chopsticks holding poses by Bayesian Optimization (BO) and Deep Reinforcement Learning (DRL), which works for multiple gripping styles and hand morphologies without the need of example data. Given as input the discovered gripping poses and desired objects to be moved, we build physics-based hand controllers to accomplish relocation tasks in two stages. First, kinematic trajectories are synthesized for the chopsticks and hand in a motion planning stage. The key components of our motion planner include a grasping model to select suitable chopsticks configurations for grasping the object, and a trajectory optimization module to generate collision-free chopsticks trajectories. Then we train physics-based hand controllers through DRL again to track the desired kinematic trajectories produced by the motion planner. We demonstrate the capabilities of our framework by relocating objects of various shapes and sizes, in diverse gripping styles and holding positions for multiple hand morphologies. Our system achieves faster learning speed and better control robustness, when compared to vanilla systems that attempt to learn chopstick-based skills without a gripping pose optimization module and/or without a kinematic motion planner

Synthetic O-Acetyl- N-glycolylneuraminic Acid Oligosaccharides Reveal Host-Associated Binding Patterns of Coronaviral Glycoproteins.

A panel of O-acetylated N-glycolylneuraminic acid oligosaccharides has been prepared by diversification of common synthetic precursors by regioselective de- O-acetylation by coronaviral hemagglutinin-esterase (HE) combined with C7-to-C9 acetyl ester migration. The resulting compound library was printed on streptavidin-coated glass slides to give a microarray to investigate receptor binding specificities of viral envelope glycoproteins, including spike proteins and HEs from animal and human coronaviruses. It was found that the binding patterns of the viral proteins for N-glycolylated sialosides differ considerable from those of the previously synthesized N-acetylated counterparts. Generally, the spike proteins tolerate N-glycolyl modification, but selectivities differ among viruses targeting different hosts. On the other hand, the lectin domain of the corresponding HEs showed a substantial decrease or loss of binding of N-glycolylated sialosides. MD simulations indicate that glycolyl recognition by HE is mediated by polar residues in a loop region (109-119) that interacts with the 5- N-glycolyl moiety. Collectively, the results indicate that coronaviruses have adjusted their receptor fine specificities to adapt to the sialoglycome of their host species

In vitro expression and analysis of the 826 human G protein-coupled receptors

ABSTRACT G protein-coupled receptors (GPCRs) are involved in all human physiological systems where they are responsible for transducing extracellular signals into cells. GPCRs signal in response to a diverse array of stimuli including light, hormones, and lipids, where these signals affect downstream cascades to impact both health and disease states. Yet, despite their importance as therapeutic targets, detailed molecular structures of only 30 GPCRs have been determined to date. A key challenge to their structure determination is adequate protein expression. Here we report the quantification of protein expression in an insect cell expression system for all 826 human GPCRs using two different fusion constructs. Expression characteristics are analyzed in aggregate and among each of the five distinct subfamilies. These data can be used to identify trends related to GPCR expression between different fusion constructs and between different GPCR families, and to prioritize lead candidates for future structure determination feasibility

Relationship between the Expression of PRDM14 in Non-small Cell Lung Cancer and the Clinicopathologic Characteristics

Background and objective The positive regulatory domain proteins (PRDM) are family of transcriptional regulation related to the formation of human tumor factor and play key roles in the cell differentiation and malignant transformation. PRDM14 is a member of the PRDM family. The aim of this study is to detect the expression of PRDM14 in non-small cell lung cancer (NSCLC) tissues, and analyze its relationship with clinicopathologic characteristics of NSCLC. Methods PRDM14 expression was detected in 70 NSCLC specimens and 7 paracancerous tissues using the immunohistochemistry (SP method). The PRDM14 protein expression was determined in 42 NSCLC specimens and 42 paracancerous tissues by Western blot. Results Among 70 NSCLC specimens, 8 specimens showed weak expression of PRDM14 (11.43%, 8/70), 62 specimens showed moderate to strong staining of PRDM14 (88.57%, 62/70), whereas 7 paracancerous specimens showed weak staining extent. PRDM14 expression level was positively correlated with differentiation (P=0.046) and histological type (P=0.047). The positive cytoplasmic expression of PRDM14 in highly differentiated NSCLC, the low expression of PRDM14 in poorly differentiated NSCLC. The results of Western blot showed that there were significant difference between the two groups (P < 0.001); expression of PRDM14 was conspicuous in NSCLC specimens but low in paracancerous tissues. PRDM14 expression level was positively correlated with differentiation (P=0.017). The positive cytoplasmic expression of PRDM14 in highly differentiated NSCLC, the low expression of PRDM14 in poorly differentiated NSCLC. Conclusion The high expression of PRDM14 in NSCLC is associated with differentiation and histological type. The PRDM14 may play an important role in the development of NSCLC

Distinguishing the Multifactorial Impacts on Ecosystem Services under the Long-Term Ecological Restoration in the Gonghe Basin of China

The ongoing shifts in climate, coupled with human activities, are leading to significant land desertification; thus, understanding the long-term variations in ecosystem services as well as the driving factors has a significant value for ensuring ecological security in ecologically fragile arid regions. In this study, we used the RUSLE, RWEQ, CASA, and InVEST models to evaluate five typical ecosystem services (ESs) from 1990 to 2020 in the Gonghe Basin, including soil conservation, sand fixation, carbon sequestration, water yield, and habitat quality. Then, we analyzed the trade-offs between ESs and proposed scientific indications. Finally, we identified the driving mechanisms of ES spatiotemporal variations. The results showed that (1) the ecosystem services in the Gonghe Basin have, overall, improved over the past 30 years. Soil conservation, sand fixation, carbon sequestration, and water yield showed upward trends, while habitat quality showed a downward trend. (2) The relationships between ESs in the Gonghe Basin were characterized by strong synergies and weak trade-offs, with significant spatial heterogeneity in terms of the trade-off intensity. In addition, the implementation of ecological engineering may strengthen the intensity of the trade-offs. (3) Among all the factors (temperature, precipitation, wind speed, NDVI, land use type, slope, DEM and soil type) that affected ESs, NDVI had the greatest impact, and the explanatory power was 49%, followed by soil type. The explanatory power of the interactions between each factor was higher than that of a single factor, and the interaction between NDVI and soil type had the greatest impact. ESs increased by 12% mainly due to the implementation of ecological engineering projects and natural factors. The most suitable area for ESs was the southeastern edge of the Gonghe Basin. Our study will enrich the understanding of the mechanisms of ecosystem services in drylands and provide a scientific basis for the future implementation of ecological engineering on the Qinghai Tibet Plateau

Analysis of Low-Velocity Impact Resistance of Carbon Fiber Reinforced Polymer Composites Based on the Content of Incorporated Graphite Fluoride

As a graphite derivative, graphite fluoride (GrF) has a remarkable fracture toughness improvement effect on epoxy materials. The fracture toughness variation of the epoxy could exert an influence on the low velocity impact resistance of the corresponding carbon fiber reinforced polymer (CFRP) composite. Therefore, the dependence of the low velocity impact resistance of the incorporated CFRP on the GrF content is worth analyzing. Here, different contents of GrF were applied to incorporate CFRP laminates and planned to find the optimal GrF content, in turn leading to the best impact resistance. Using a drop-weight impact test, the load vs. time curves and load vs. displacement curves were obtained. The incipient damage loads and maximum loads of various GrF contents of the samples were compared carefully. The absorbed energies during the impact process were calculated. The trend of absorbed energy decreased up to the 1 wt% sample, then increased significantly with the rise of GrF content. This deflection behavior can be explained by the combination of crack pinning, crack deflection and crack propagation, due to the rise in GrF content. Through the ultrasonic C-scan evaluation, the delamination areas of different GrF content of samples were measured. The trend of delamination area variation was accordant with the trend of absorbed energy variation. This presents a demonstration of the correlation between the absorbed energy and the damage level. The SEM images of the fracture surfaces were analyzed for the deflection behavior of the fracture toughness with various GrF contents. The plot of residual compression strength versus GrF content further indicated the 1 wt% was the optimal content at which the incorporated GrF endowed the most impact-resistant property to the CFRP laminates

Synthetic O-Acetylated Sialosides and their Acetamido-deoxy Analogues as Probes for Coronaviral Hemagglutinin-esterase Recognition

O-Acetylation is a common modification of sialic acids that can occur at carbons 4-, 7-, 8-, and/or 9. Acetylated sialosides are employed as receptors by several betacoronaviruses and toroviruses, and by influenza C and D viruses. The molecular basis by which these viruses recognize specific O-acetylated sialosides is poorly understood, and it is unknown how viruses have evolved to recognize specific O-acetylated sialosides expressed by their host. Here, we describe a chemoenzymatic approach that can readily provide sialoglycan analogues in which acetyl esters at C4 and/or C7 are replaced by stabilizing acetamide moieties. The analogues and their natural counterparts were used to examine the ligand requirements of the lectin domain of coronaviral hemagglutinin-esterases (HEs). It revealed that HEs from viruses targeting different host species exhibit different requirements for O-acetylation. It also showed that ester-to-amide perturbation results in decreased or loss of binding. STD NMR and molecular modeling of the complexes of the HE of BCoV with the acetamido analogues and natural counterparts revealed that binding is governed by the complementarity between the acetyl moieties of the sialosides and the hydrophobic patches of the lectin. The precise spatial arrangement of these elements is important, and an ester-to-amide perturbation results in substantial loss of binding. Molecular Dynamics simulations with HEs from coronaviruses infecting other species indicate that these viruses have adapted their HE specificity by the incorporation of hydrophobic or hydrophilic elements to modulate acetyl ester recognition

Parallel Validation of the Ng-Test Carba 5 and the Xpert Carba-R for Detection and Characterization of Carbapenem-Resistant Enterobacterales Causing Bloodstream Infections

The rapid detection and characterization of carbapenemases in isolates of Enterobacterales are crucial for precise antibiotic administration and infection control. This article reports the findings from a parallel evaluation of the NG-Test Carba 5 (NG Biotech, Guipry, France) and Xpert Carba-R (Cepheid, Sunnyvale, CA) assays in the detection and differentiation of five carbapenemases [imipenem-resistant phenotype (IMP), Klebsiella pneumoniae carbapenemase, New Delhi metallo-β-lactamase (NDM), oxacillin-hydrolyzing β-lactamase (OXA)-48–like, and Verona integron-encoded metallo-β-lactamase] or the genes that encode them. A total of 122 isolates recovered from blood cultures and 106 positive blood culture broth (BCB) specimens, including 134 Klebsiella pneumoniae, 54 Escherichia coli, 27 Enterobacter cloacae, 8 Klebsiella oxytoca, 2 Klebsiella aerogenes, and 3 Citrobacter freundii, were collected from two tertiary hospitals (Xi\u27an, China). Using PCR sequencing techniques, 89 isolates and 29 BCB specimens were determined to be Enterobacterales harboring carbapenem-resistance genes. In comparison to the PCR sequencing results, the specificities with both the NG-Test Carba 5 and Xpert Carba-R assays were 100%; the sensitivities were 92.1% and 100%, respectively, for recovered isolates and 79.3% and 100% for BCB specimens. The NG-Test Carba 5 missed eight NDM, four OXA-48–like, and one IMP β-lactamases in specimens containing two or three carbapenemase types. In summary, the NG-Test Carba 5 assay may yield false-negative results if isolates or BCB specimens contain two or three carbapenemases

Synthetic O-acetylated sialosides facilitate functional receptor identification for human respiratory viruses

The transmission of viruses from animal reservoirs to humans poses major threats to public health. Preparedness for future zoonotic outbreaks requires a fundamental understanding of how viruses of animal origin have adapted to binding to a cell surface component and/or receptor of the new host. Here we report on the specificities of human and animal viruses that engage with O-acetylated sialic acid, which include betacoronaviruses, toroviruses and influenza C and D viruses. Key to these studies was the development of a chemoenzymatic methodology that can provide almost any sialate-acetylation pattern. A collection of O-acetylated sialoglycans was printed as a microarray for the determination of receptor specificity. These studies showed host-specific patterns of receptor recognition and revealed that three distinct human respiratory viruses uniquely bind 9-O-acetylated α2,8-linked disialoside. Immunofluorescence and cell entry studies support that such a glycotope as part of a ganglioside is a functional receptor for human coronaviruses. [Figure not available: see fulltext.

Synthetic O-acetylated sialosides facilitate functional receptor identification for human respiratory viruses

The transmission of viruses from animal reservoirs to humans poses major threats to public health. Preparedness for future zoonotic outbreaks requires a fundamental understanding of how viruses of animal origin have adapted to binding to a cell surface component and/or receptor of the new host. Here we report on the specificities of human and animal viruses that engage with O-acetylated sialic acid, which include betacoronaviruses, toroviruses and influenza C and D viruses. Key to these studies was the development of a chemoenzymatic methodology that can provide almost any sialate-acetylation pattern. A collection of O-acetylated sialoglycans was printed as a microarray for the determination of receptor specificity. These studies showed host-specific patterns of receptor recognition and revealed that three distinct human respiratory viruses uniquely bind 9-O-acetylated α2,8-linked disialoside. Immunofluorescence and cell entry studies support that such a glycotope as part of a ganglioside is a functional receptor for human coronaviruses. [Figure not available: see fulltext.