Hybrid Chains Research Articles

Modeling and numerical analysis of Kangaroo lower body based on constrained dynamics of hybrid serial–parallel floating-base systems

This paper presents the modeling and numerical analysis of the Kangaroo lower body prototype, a novel bipedal humanoid robot developed and manufactured by PAL Robotics. Kangaroo features high-power linear electric actuators combined with unique serial–parallel hybrid chains, which allow for the positioning of all the leg actuators near the base of the robot to improve the overall mass distribution. To model and analyze such complex nonlinear mechanisms, we employ a constrained formulation that is extended to account for floating-base systems in contact with the environment. A comparison is made to demonstrate the significant improvements achieved with TALOS, another humanoid bipedal robot designed by PAL Robotics, in terms of equivalent Cartesian inertia at the feet and centroidal angular momentum. Finally, the paper includes numerical experiments conducted through simulation and preliminary tests performed on the actual Kangaroo platform.

An enhanced consensus algorithm for blockchain

Consensus plays a crucial role in blockchain technology, with the delegated proof of stake (DPoS) consensus mechanism commonly utilized in both public and hybrid chains. However, the current DPoS mechanism faces challenges such as low node engagement in voting and potential security risks posed by malicious nodes. In response, we propose the DL-DPoS (deep link–delegated proof of stake) mechanism, which builds upon the DPoS framework. The DL-DPoS incorporates the LINK incentive mechanism to encourage inactive nodes to participate in voting and leader selection. Furthermore, a comprehensive credit scoring system based on wealth, performance, and stability is introduced to enhance the security of elected nodes. The verification process is optimized to involve all nodes except the leader node, and mechanisms are in place to handle malicious attacks by degrading or removing offending nodes and redistributing their responsibilities to the LINK group. Performance testing of the DL-DPoS mechanism, conducted through blockchain simulation tests using the GO language, shows a 23% increase in throughput compared to DPoS, with over 95% node participation and improved distribution of rights and equity. These results indicate the enhanced performance, security, and stability of the DL-DPoS consensus mechanism.

Nucleic acid aptamer based thermally oxidized porous silicon/zinc oxide microarray chip for detection of ochratoxin A in cereals

A nucleic acid aptamer based thermally oxidized porous silicon/zinc oxide microarray chip was constructed for the detection of ochratoxin A. The hybrid chains formed by aptamer and complementary chains labeled with fluorescent groups and fluorescent burst groups were used as recognition molecules, and the detection of toxins was accomplished on the chip by the principle of fluorescence signal burst and recovery. The modified QuEChERS method was used for sample pretreatment and the performance of the method was evaluated. The results showed that the linear range was 0.02 ∼ 200 ng/kg with the detection limit of 0.0196 ng/kg under the optimal detection conditions. The method was applied to different cereals with the recoveries of 90.30 ∼ 111.69 %. The developed microarray chip has the advantages of being cost-effective, easy to prepare, sensitive and specific, and can provide a new method for the detection of other toxins.

Preparation of surface-active carbon dots with fluorocarbon and hydrocarbon hybrid chains via a one-pot solvothermal technique and their characterization and potential applications

Amphiphilic carbon dots (CDs) are new surface-active materials that exhibit several advantages over conventional small surfactants, such as improved stability and reduced toxicity. However, unlike for conventional small surfactants, amphiphilic CDs that simultaneously exhibit excellent surface and interfacial activities have never been achieved. Herein we prepare new amphiphilic CDs with fluorocarbon and hydrocarbon hybrid hydrophobic chains (FH-CDs) using a facile one-pot solvothermal technique. The obtained FH-CDs showed excellent surface and interfacial activities, and reduced the surface tension at critical micelle concentration and the oil-water interfacial tension to 16.7 and 2.2 mN/m, respectively. Comparison with control CDs bearing only non-hybrid hydrophobic chains demonstrated that decorating CDs with fluorocarbon and hydrocarbon hybrid chains contributed to the excellent interfacial activity, while only fluorocarbon chains contributed to good surface activity. The excellent surface and interfacial activities made FH-CDs good emulsifiers for the formation of stable water-in-oil emulsions and for the preparation of relatively uniform polystyrene spheres via emulsion polymerization. Moreover, FH-CD was a good wetting agent, whose aqueous solution could wet numerous different surfaces, including the commonly non-wettable amphiphobic polytetrafluoroethylene.

Chondroitin Sulfate/Dermatan Sulfate Hybrid Chains from Swim Bladder: Isolation, Structural Analysis, and Anticoagulant Activity.

Glycosaminoglycans (GAGs) with unique structures from marine animals show intriguing pharmacological activities and negligible biological risks, providing more options for us to explore safer agents. The swim bladder is a tonic food and folk medicine, and its GAGs show good anticoagulant activity. In this study, two GAGs, CMG-1.0 and GMG-1.0, were extracted and isolated from the swim bladder of Cynoscion microlepidotus and Gadus morhua. The physicochemical properties, precise structural characteristics, and anticoagulant activities of these GAGs were determined for the first time. The analysis results of the CMG-1.0 and GMG-1.0 showed that they were chondroitin sulfate (CS)/dermatan sulfate (DS) hybrid chains with molecular weights of 109.3 kDa and 123.1 kDa, respectively. They were mainly composed of the repeating disaccharide unit of -{IdoA-α1,3-GalNAc4S-β1,4-}- (DS-A). The DS-B disaccharide unit of -{IdoA2S-α1,3-GalNAc4S-β1,4-}- also existed in both CMG-1.0 and GMG-1.0. CMG-1.0 had a higher proportion of CS-O disaccharide unit -{-GlcA-β1,3-GalNAc-β1,4-}- but a lower proportion of CS-E disaccharide unit -{-GlcA-β1,3-GalNAc4S6S-β1,4-}- than GMG-1.0. The disaccharide compositions of the GAGs varied in a species-specific manner. Anticoagulant activity assay revealed that both CMG-1.0 and GMG-1.0 had potent anticoagulant activity, which can significantly prolong activated partial thromboplastin time. GMG-1.0 also can prolong the thrombin time. CMG-1.0 showed no intrinsic tenase inhibition activity, while GMG-1.0 can obviously inhibit intrinsic tenase with EC50 of 58 nM. Their significantly different anticoagulant activities may be due to their different disaccharide structural units and proportions. These findings suggested that swim bladder by-products of fish processing of these two marine organisms may be used as a source of anticoagulants.

SUMO enhances unfolding of SUMO–polyubiquitin-modified substrates by the Ufd1/Npl4/Cdc48 complex

The Ufd1/Npl4/Cdc48 complex is a universal protein segregase that plays key roles in eukaryotic cellular processes. Its functions orchestrating the clearance or removal of polyubiquitylated targets are established; however, prior studies suggest that the complex also targets substrates modified by the ubiquitin-like protein SUMO. Here, we show that interactions between Ufd1 and SUMO enhance unfolding of substrates modified by SUMO-polyubiquitin hybrid chains by the budding yeast Ufd1/Npl4/Cdc48 complex compared to substrates modified by polyubiquitin chains, a difference that is accentuated when the complex has a choice between these substrates. Incubating Ufd1/Npl4/Cdc48 with a substrate modified by a SUMO-polyubiquitin hybrid chain produced a series of single-particle cryo-EM structures that reveal features of interactions between Ufd1/Npl4/Cdc48 and ubiquitin prior to and during unfolding of ubiquitin. These results are consistent with cellular functions for SUMO and ubiquitin modifications and support a physical model wherein Ufd1/Npl4/Cdc48, SUMO, and ubiquitin conjugation pathways converge to promote clearance of proteins modified with SUMO and polyubiquitin.

Sustainable Innovation through Developing Hybrid Agri-Food Supply Chains: A Case in South-Eastern Spain.

We analyze the incipient development of short supply chains for fresh fruit and vegetables from conventional agri-food chains, leading to the emergence of hybrid chains. We have sought to answer the research question of how and why hybrid food supply chains has been initiated by studying this phenomenon in south-eastern Spain. We analyzed the 20 main Spanish fruit and vegetable exporters, identifying the 9 that have developed short channels. Subsequently, we conducted a case study of the one considered most relevant, identifying the stages of this short chain, analyzing the tasks to be performed in the different phases of the SCS, studying which are common to both and where the differences in the processes arise. The results show the synergies that make them coexist successfully, such as the sharing of personnel, infrastructures and services, complementarity in the product range, thus avoiding food waste, or knowledge of consumer tastes and needs.

Building Resilience Attributes of Supply Chains from the Perspective of their Types

Abstract We are currently dealing with disruptions in supply chains. They come from faulty production systems, in poor organization of distribution processes or are related to external factors, often unseen. Consequently, it is necessary to build resistant chains. This article discusses this topic in the context of the basic types of supply chains, i.e. agile, lean and green. The aim of the study was to assess the types of chains in which the tested production entities are embedded and check if the proposed models of building resilience take this into account. The reason this should be investigated further, is to indicate relationships in areas that are rarely captured in research models. Both quantitative and qualitative methods were used in the work. Interviews were conducted in over seventy subjects and a critical analysis of the literature on model of resilient supply chains was performed. As a result of the work undertaken, it can be concluded, inter alia, that in the economic reality, there are hybrid chains in which the characteristics of pro-saving chains prevail. It was also established that the proposed research models for resilient chains should take into account, to greater extent, accents compatible with the nature of the chains occurring an economic reality. It is also necessary to extend their content to include pro-environmental components. At the same time, it is not unequivocal that the chains with the advantage of agility-related attributes are more resistant than the chains in which the greater concentration is attributed to the attributes of lean or green chains. Determining this requires further research.

Emerging agricultural expansion in northern regions: Insights from land-use research

Emerging agricultural expansion in northern regions: Insights from land-use research

A modular toolbox to generate complex polymeric ubiquitin architectures using orthogonal sortase enzymes

The post-translational modification of proteins with ubiquitin (Ub) and Ub-like modifiers (Ubls) represents one of the most important regulators in eukaryotic biology. Polymeric Ub/Ubl chains of distinct topologies control the activity, stability, interaction and localization of almost all cellular proteins and elicit a variety of biological outputs. Our ability to characterize the roles of distinct Ub/Ubl topologies and to identify enzymes and receptors that create, recognize and remove these modifications is however hampered by the difficulty to prepare them. Here we introduce a modular toolbox (Ubl-tools) that allows the stepwise assembly of Ub/Ubl chains in a flexible and user-defined manner facilitated by orthogonal sortase enzymes. We demonstrate the universality and applicability of Ubl-tools by generating distinctly linked Ub/Ubl hybrid chains, and investigate their role in DNA damage repair. Importantly, Ubl-tools guarantees straightforward access to target proteins, site-specifically modified with distinct homo- and heterotypic (including branched) Ub chains, providing a powerful approach for studying the functional impact of these complex modifications on cellular processes.

Preparation of Silicophosphate Alternating Hybrid Copolymers via Nonaqueous Acid-Base Reactions of Phosphoric Acid and Organo-Bridged Bis(chlorosilane).

A design of atomic and oligomer level structure in organic-inorganic hybrid materials is highly important for various applications. Nonaqueous acid-base reaction allows us to prepare silicophosphates with controlled inorganic networks (–(O–P–O–Si)n) at atomic level because phosphorous and silicon-based precursors can react directly, resulting in an alternating copolymer network. Organic functionalization in those materials has been realized so far by using organic-modified phosphorous acid and/or organo-chlorosilane as precursors. In the present study, silicophosphate oligomers exhibiting inorganic-organic hybrid chains of (–(O–P–O–Si–R–Si)n) (R: bridging organic functional groups), are prepared from phosphoric acid and organo-bridged bis(chlorosilane). The 1, 2-bis(chlorodimethylsilyl)ethane ((C2H4)(Me2SiCl)2) and 1, 4-bis(chlorodimethylsilyl)benzene ((C6H4)(Me2SiCl)2) were used as organo-bridged bis(chlorosilane). Different types of silicophosphate oligomers with different network structures and terminal groups (P-OH and/or Si-Cl) were prepared by changing the reaction temperature and molar ratio of precursors. The formation of low molecular weight oligomers of ring and cage morphologies (ring tetramer, cage pentamer, and ring hexamer) is suggested in the product prepared from phosphoric acid and (C6H4)(Me2SiCl)2 molecule at 150 °C. Those silicophosphate hybrid oligomers are expected to be used as building blocks of hybrid materials with well-defined network structures for desired functionalities.

Planar Impacts in Hybrid Chains of Cylinders and Balls

Abstract In this paper, we study low-velocity multiple impacts of chains of balls and cylinders. We use three types of materials including steel, wood, and rubber. We perform collision experiments of balls and cylinders of three-, four-, and five-body chains and obtain their corresponding pre- and post-impact velocities. Although the common solution methods such as rigid body and bimodal models can not deal with this type of problems, we use a discretization method presented in Alluhydan et al. (2019, “On Planar Impacts of Cylinders and Balls,” ASME J. Appl. Mech., 86(7), p. 0710091) to accurately calculate the post-impact velocities of the colliding bodies in the chain. We use the bimodal Hertz–Crook contact force model and employ the ball-ball coefficient of restitution at the contacting segments to analyze the impact dynamics of the colliding objects. A segmentation method is used for ball-cylinder and cylinder-cylinder Collisions. The number of segments for each collision is determined by using a relationship that relates the stiffness ratio of two objects to the number of the segments. In ball-ball collisions, however, we do not use the segmentation method. The outcomes demonstrate that the overall average percentage error of post-impact velocities among experimental results and numerical predictions was less than 6.2% for all results.

Microfluidic Chip for Multiplex Detection of Trace Chemical Contaminants Based on Magnetic Encoded Aptamer Probes and Multibranched DNA Nanostructures as Signal Tags.

The development of multiplex assays to simultaneously monitor multiclass chemical contaminants that commonly coexist in foods, such as heavy metal ions, antibiotics, and estrogen residues, is gaining attention. Here, a microfluidic chip (MC)-based multianalysis method coupled with magnetic encoded aptamer probes was used for simultaneous detection of kanamycin, 17β-estradiol, and lead ion (Pb2+). Using this innovative strategy, the magnetic bead (MB)-based encoded probes labeled with aptamer hybrid chains were first used to selectively capture multiple targets, followed by generating single-stranded primers. The primers triggered a multibranched hybridization chain reaction (mHCR). Finally, three kinds of complementary strands (C-DNAs) with different lengths were hybridized with the arms of the mHCR products to form three types of multibranched DNA nanostructures. The decrement signals of C-DNAs were employed for qualification of targets. As the signal tags corresponded to different targets, the DNA nanostructures realized "one target for the decrease of massive C-DNAs" to improve sensitivity. The use of MB-based encoded probes could achieve magnetic separation to eliminate interference in the complex. The detection limits of this method were 1.76 × 10-4 nM (kanamycin), 1.18 × 10-4 nM (17β-estradiol), and 1.29 × 10-4 nM (lead ion). Furthermore, the MC platform is reusable and can be used for more than 4000 samples. The assay combining the MC with MB-based encoded probes with multibranched DNA signal tags offers a universal, reusable, and high-throughput detection platform for screening multiclass chemical contaminants in food samples with complex matrices.

Crystal structure and antibacterial activity of polyoxometalate cobalt-ciprofloxacin complex

A new antibacterial complex based on the quinolone antibacterial drug ciprofloxacin (CF) and the polyoxometalates (POMs), [Co II (C17H18FN3O3)2]2H2[SiW12O40]·2H2O (1), has been synthesized and comprehensively characterized by elemental analyses, IR, and single crystal X-ray diffraction approaches. Single-crystal structural analysis revealed that complex 1 is composed of Keggin clusters grafted by binuclear cobalt clusters and water molecules. Moreover, we observed that complex 1 formed inorganic-organic hybrid chains via covalent bonds, and could also form a 2D supramolecular layer structure by N··O stacking. In this work, we assessed the antibacterial activities of complex 1 using Escherichia coli, Staphylococcus aureus, and Bacillus subtilis strains. In general, we observed that the antibacterial activities of complex 1 were slightly higher than that of free CF at the same mass concentrations. Overall, the results suggest that introduction of POMs to modify the CF not only affects the final structure of CF but also affects its antibacterial activities.

Highly efficient and very robust blue-excitable yellow phosphors built on multiple-stranded one-dimensional inorganic-organic hybrid chains.

Inorganic-organic hybrid semiconductors are promising candidates for energy-related applications. Here, we have developed a unique class of multiple-stranded one-dimensional (1D) structures as very robust and efficient lighting phosphors. Following a systematic ligand design strategy, these structures are constructed by forming multiple coordination bonds between adjacent copper iodide inorganic building units Cu m I m (m = 2, 4, 6) (e.g. dimer, tetramer and hexamer clusters) and strong-binding bidentate organic ligands with low LUMO energies which give rise to infinite 1D chains of high stability and low bandgaps. The significantly enhanced thermal/photostability of these multiple-stranded chain structures is largely attributed to the multi-dentate nature and enhanced Cu-N bonding, and their excellent blue excitability is a result of using benzotriazole based ligands with low-lying LUMO energies. These facts are confirmed by Density Functional Theory (DFT) calculations. The luminescence mechanism of these compounds is studied by temperature dependent photoluminescence experiments. High internal quantum yields (IQYs) are achieved under blue excitation, marking the highest value reported so far for crystalline inorganic-organic hybrid yellow phosphors. Excellent thermal- and photo-stability, coupled with high luminescence efficiency, make this class of materials promising candidates for use as rare-earth element (REE) free phosphors in energy efficient general lighting devices.

Enzymatic Synthesis of Human Milk Fucosides α1,2‐Fucosyl para‐Lacto‐N‐Hexaose and its Isomeric Derivatives

AbstractEnzymatic synthesis of para‐lacto‐N‐hexaose and its isomeric structures as well as those α1,2‐fucosylated variants naturally occurring in human milk oligosaccharide (HMOs) was achieved using a sequential one‐pot enzymatic system. Three glycosylation routes comprising bacterial glycosyltransferases and corresponding sugar‐nucleotide‐generating enzymes were developed to facilitate efficient production of extended type‐1 and type‐2 N‐acetyllactosamine (LacNAc) backbones and hybrid chains. Further fucosylation efficiency of two α1,2‐fucosyltransferases on both type‐1 and type‐2 chains of the hexasaccharide was investigated to achieve practical synthesis of the fucosylated glycans. The availability of structurally defined HMOs offers a practical approach for investigating future biological applications.magnified image

SemaDrift: A hybrid method and visual tools to measure semantic drift in ontologies

Semantic drift is an active field of research, aiming to identify and measure changes in ontologies across versions in time, closely related to several fields such as ontology evolution and versioning. However, practical and widely adopted methods for measuring semantic drift are mostly either not directly applied to Semantic Web formalisms or largely dependent on specific models and domains. This paper presents a novel hybrid method, which combines existing identity-based and morphing-based approaches, and, in turn, introduces further insights such as hybrid chains of concepts across ontology versions and concept stability ranking. Furthermore, it introduces the SemaDrift Application Suite, which integrates both new and existing methods, including structural and text similarity measures, provided as open-source. The applications offer a graphical user interface to calculate and visually explore semantic drift metrics, in order to support and promote their use to Semantic Web and domain experts alike. Specifically, the SemaDrift plugin for the popular Protègè platform is intended for ontology engineers, while SemaDriftFx allows a wider audience of users to visually investigate drift either as numeric output or visually through graphs. Two use case scenarios demonstrate the applicability and usefulness of the methods and tools in the domain of digital preservation and Web Services, with insights previously hard to obtain. Standard scale and concrete end-user evaluation tasks were used to acquire positive preliminary feedback on the usability of the SemaDriftFx tool.

DSE promotes aggressive glioma cell phenotypes by enhancing HB-EGF/ErbB signaling.

Remodeling of the extracellular matrix (ECM) in the tumor microenvironment promotes glioma progression. Chondroitin sulfate (CS) proteoglycans appear in the ECM and on the cell surface, and can be catalyzed by dermatan sulfate epimerase to form chondroitin sulfate/dermatan sulfate (CS/DS) hybrid chains. Dermatan sulfate epimerase 1 (DSE) is overexpressed in many types of cancer, and CS/DS chains mediate several growth factor signals. However, the role of DSE in gliomas has never been explored. In the present study, we determined the expression of DSE in gliomas by consulting a public database and conducting immunohistochemistry on a tissue array. Our investigation revealed that DSE was upregulated in gliomas compared with normal brain tissue. Furthermore, high DSE expression was associated with advanced tumor grade and poor survival. We found high DSE expression in several glioblastoma cell lines, and DSE expression directly mediated DS chain formation in glioblastoma cells. Knockdown of DSE suppressed the proliferation, migration, and invasion of glioblastoma cells. In contrast, overexpression of DSE in GL261 cells enhanced these malignant phenotypes and in vivo tumor growth. Interestingly, we found that DSE selectively regulated heparin-binding EGF-like growth factor (HB-EGF)-induced signaling in glioblastoma cells. Inhibiting epidermal growth factor receptor (EGFR) and ErbB2 with afatinib suppressed DSE-enhanced malignant phenotypes, establishing the critical role of the ErbB pathway in regulating the effects of DSE expression. This evidence indicates that upregulation of DSE in gliomas contributes to malignant behavior in cancer cells. We provide novel insight into the significance of DS chains in ErbB signaling and glioma pathogenesis.

Controlled Gold Nanorod Reorientation and Hexagonal Order in Micromolded Gold Nanorod@pNIPAM Microgel Chain Arrays.

A one-step soft lithography based pathway to manufacture aligned gold nanorod@poly-(N-isopropylacrylamide) (GNR@pNIPAM) hybrid chains with hexagonal arrangement of the nanorods and with an anisotropic optical response is presented. After demonstration of an efficient synthesis protocol, yielding uniform composite microgels in high concentration, a micromolding procedure using wrinkled polydimethylsiloxane (PDMS) templates to fabricate aligned hybrid chains is introduced. It is found that the self-assembled GNR@pNIPAM microgels inside the PDMS wrinkle grooves can be transferred onto solid substrates, on which they exhibit a hexagonal order, as confirmed by small-angle X-ray scattering. Further, it is shown that the application of minimized PDMS wrinkle dimensions aligns GNRs inside the pNIPAM microgels, and that the optical response of such molded assemblies is anisotropic.

Synthesis of novel bis(Triol)-functionalized Anderson clusters serving as potential synthons for forming organic-inorganic hybrid chains.

Three novel bis(Triol)-functionalized Anderson cluster derivatives (POM-L-POM, POM-L, L-POM-L) were efficiently synthesized, which manifest interesting self-assembly and synergistic effects. They provided strong support in synthons, applications in syntheses and properties for designing organic-inorganic hybrid chains.