Terminal Position Research Articles

Classification of chronic ankle instability using machine learning technique based on ankle kinematics during heel rise in delivery workers.

Ankle injuries in delivery workers (DWs) are often caused by trips, and high recurrence rates of ankle sprains are related to chronic ankle instability (CAI). Heel rise requires joint angles and moments similar to those of the terminal stance phase of walking that the foot supinates. Thus, our study aimed to develop, determine, and compare the predictive performance of statistical machine learning models to classify DWs with and without CAI using ankle kinematics during heel rise. In total, 203 DWs were screened for eligibility. Seven predictors were included in our study (age, work duration, body mass index, calcaneal stance position angle [CSPA] in the initial and terminal positions during heel rise, calcaneal movement during heel rise [CMHR], and plantar flexion angle during heel rise). Six machine learning algorithms, including logistic regression, decision tree, AdaBoost, Extreme Gradient boosting machines, random forest, and support vector machine, were trained. The random forest model (area under the curve [AUC], 0.967 [excellent]; F1, 0.889; accuracy, 0.925) confirmed the best predictive performance in the test datasets among the six machine learning models. For Shapley Additive Explanations, old age, low CMHR, high CSPA in the initial position, high PFA, long work duration, low CSPA in the terminal position, and high body mass index were the most important predictors of CAI in the random forest model. Ankle kinematics during heel rise can be considered in the classification of DWs with and without CAI.

Channel-enhanced Transmission-reflection Switchable Reconfigurable Intelligent Surface with Arbitrary Source and Terminal Positions

Channel-enhanced Transmission-reflection Switchable Reconfigurable Intelligent Surface with Arbitrary Source and Terminal Positions

Enzymatic synthesis of ligand-bearing oligonucleotides for the development of metal-responsive DNA materials.

Metal-mediated artificial base pairs are some of the most promising building blocks for constructing DNA-based supramolecules and functional materials. These base pairs are formed by coordination bonds between ligand-type nucleobases and a bridging metal ion and have been exploited to develop metal-responsive DNA materials and DNA-templated metal arrays. In this review, we provide an overview of methods for the enzymatic synthesis of DNA strands containing ligand-type artificial nucleotides that form metal-mediated base pairs. Conventionally, ligand-bearing DNA oligomers have been synthesized via solid-phase synthesis using a DNA synthesizer. In recent years, there has been growing interest in enzymatic methods as an alternative approach to synthesize ligand-bearing DNA oligomers, because enzymatic reactions proceed under mild conditions and do not require protecting groups. DNA polymerases are used to incorporate ligand-bearing unnatural nucleotides into DNA, and DNA ligases are used to connect artificial DNA oligomers to natural DNA fragments. Template-independent polymerases are also utilized to post-synthetically append ligand-bearing nucleotides to DNA oligomers. In addition, enzymatic replication of DNA duplexes containing metal-mediated base pairs has been intensively studied. Enzymatic methods facilitate the synthesis of DNA strands containing ligand-bearing nucleotides at both internal and terminal positions. Enzymatically synthesized ligand-bearing DNAs have been applied to metal-dependent self-assembly of DNA structures and the allosteric control of DNAzyme activity through metal-mediated base pairing. Therefore, the enzymatic synthesis of ligand-bearing oligonucleotides holds great potential in advancing the development of various metal-responsive DNA materials, such as molecular sensors and machines, providing a versatile tool for DNA supramolecular chemistry and nanotechnology.

Karyotypic characterization of Centromochlus schultzi Rössel 1962 (Auchenipteridae, Centromochlinae) from the Xingu River basin: New inferences on chromosomal evolution in Centromochlus.

Centromochlinae is a widely diverse subfamily with more than 50 species and several taxonomic conflicts due to morphological similarity between Tatia and Centromochlus species. However, cytogenetic studies on this group have been limited to only four species so far. Therefore, here we present the karyotype of Centromochlus schultzi from the Xingu River in Brazil using classic cytogenetic techniques, physical mapping of the 5S and 18S rDNAs, and telomeric sequences (TTAGGG)n. The species had 58 chromosomes, simple NORs and 18S rDNA sites. Heterochromatic regions were detected on the terminal position of most chromosomes, including pericentromeric and centromeric blocks that correspond to interstitial telomeric sites. The 5S rDNA had multiple sites, including a synteny with the 18S rDNA in the pair 24st, which is an ancestral feature for Doradidae, sister group of Auchenipteridae, but appears to be a homoplastic trait in this species. So far, C. schultzi is only the second species within Centromochlus to be karyotyped, but it has already presented characteristics with great potential to assist in future discussions on taxonomic issues in the subfamily Centromochlinae, including the first synteny between rDNAs in Auchenipteridae and also the presence of heterochromatic ITSs that could represent remnants of ancient chromosomal fusions.

Functionalized cyanostilbene-based nano-AIEgens: multipoint binding interactions for improved sensing of gallic acid in real-life food samples.

Cyano-substituted stilbene (CSS) derivatives have been synthesized that can form luminescent nanoscopic assemblies in an aqueous medium. The optical properties of such materials, as governed by the relative ratios of their monomer and aggregated forms, are found to be susceptible to pH and temperature of the medium. The compound with boronic acid attached at the terminal positions shows a turn-on fluorescence response (LOD: 15.4 ppb) with gallic acid (GA). The mechanistic studies indicate that the 1,2-diol unit of GA is involved in ester formation with the boronic acid residue, while the carboxylic end engages in hydrogen bonding interaction with the nitrile unit. Such multi-point binding interaction provides better selectivity over other structurally similar analytes. Moreover, the distinct aggregation properties of such boronate ester derivatives are responsible for the GA-specific optical response. The sensory system has been utilized for the determination of the levels of GA derivatives in tea (green tea and black tea) and various fruit (mango, orange, guava, pomegranate) extracts. In all cases, the estimated values of GAE were found to be in the same range reported by others. Finally, low-cost, chemically-modified paper strips have been designed for rapid, on-location detection of GA.

Gradual Coordination and Reversible P-P Bond Activation of a P3 -Unit with Transition Metal Carbonyls.

Coordination of a stereochemically defined P3 -chain to a series of transition metal carbonyls [M(CO)x ]z- (M=Mn (x=5, z=1), Fe (x=4, z=2) or Co (x=4, z=1)) is explored using a [3]ferrocenophane scaffold. A gradual transition from η1 -, η2 - toη3 -coordination is observed where in the η2 -mode the terminal positions of the phosphorus chain are bridged. With an excess of cobalt carbonyl successive P-P bond activation and gradual separation of the central phosphorus atoms from the phosphorus chain has been observed. This process is reversible and with suitable reagents such as methyl lithium, the P3 -unit is regenerated in stereospecific manner. The bonding situation and steps of the gradual P-P bond activation are investigated by DFT calculations as well as experimental methods (e.g., NMR spectroscopy, X-ray crystallography).

New l-Rhamnose-Binding Lectin from the Bivalve Glycymeris yessoensis: Purification, Partial Structural Characterization and Antibacterial Activity.

In this study, a new l-rhamnose-binding lectin (GYL-R) from the hemolymph of bivalve Glycymeris yessoensis was purified using affinity and ion-exchange chromatography and functionally characterized. Lectin antimicrobial activity was examined in different ways. The lectin was inhibited by saccharides possessing the same configuration of hydroxyl groups at C-2 and C-4, such as l-rhamnose, d-galactose, lactose, l-arabinose and raffinose. Using the glycan microarray approach, natural carbohydrate ligands were established for GYL-R as l-Rha and glycans containing the α-Gal residue in the terminal position. The GYL-R molecular mass determined by MALDI-TOF mass spectrometry was 30,415 Da. The hemagglutination activity of the lectin was not affected by metal ions. The lectin was stable up to 75 °C and between pH 4.0 and 12.0. The amino acid sequence of the five GYL-R segments was obtained with nano-ESI MS/MS and contained both YGR and DPC-peptide motifs which are conserved in most of the l-rhamnose-binding lectin carbohydrate recognition domains. Circular dichroism confirmed that GYL is a α/β-protein with a predominance of the random coil. Furthermore, GYL-R was able to bind and suppress the growth of the Gram-negative bacteria E. coli by recognizing lipopolysaccharides. Together, these results suggest that GYL-R is a new member of the RBL family which participates in the self-defense mechanism against bacteria and pathogens with a distinct carbohydrate-binding specificity.

A new small molecule DoNA binding to CAG repeat RNA

We here report a new molecule DoNA binding to a CAG repeat RNA. DoNA is a dimer of the NA molecule that we previously reported. NA binds with high affinity to a CAG repeat DNA but not significantly to a CAG repeat RNA. Binding analyses using SPR and CSI-TOF MS indicated a significant increase in the affinity of DoNA to a single stranded CAG repeat RNA compared to NA. Systematic investigation of the RNA motifs bound by DoNA using hairpin RNA models revealed that DoNA binds to the CAG units at overhang and terminal positions, and notably, it binds to the structurally flexible internal and hairpin loop region.

Understanding the Retro‐Cope Elimination Reaction of Linear Alkynes

AbstractThe bioorthogonal retro‐Cope elimination reaction of linear alkynes R3C−C≡C−X (R3 = combinations of H, MeO, F; X = H, F, Cl, Br, I) with N,N‐dimethylhydroxylamine was quantum chemically investigated using relativistic density functional theory at ZORA‐BP86/TZ2P. This novel reaction can be tuned through judicious substitution of the alkyne at both the terminal and propargylic position to render second‐order kinetics that rival and out‐compete strain‐promoted variants. Activation strain and quantitative molecular orbital analyses reveal that, both upon terminal or propargylic substitution of propyne, the main effect of substituting H for X is a lowering of the propyne LUMO which stabilizes the HOMO–LUMO interactions and thus the transition state. In the case of terminal substitution with larger halogens (X = Cl, Br, I), a secondary effect interferes: steric repulsion with these larger halogens is absorbed into a longer forming C⋯N bond leading to a more asynchronous reaction accompanied by less (not more) steric Pauli repulsion.

Position-specific carbon isotopes of propane in coal systems in China

Evaluating the origin and fate of hydrocarbons holds significance in many fields, such as energy, geology, astrobiology, biosphere, and environment. However, challenges arise in many cases owing to the limitations of conventional methods. Intramolecular isotope analysis of propane is a new technique that offers the potential to provide insights into gas formation mechanisms; however, a comprehensive understanding of the method remains limited. Specifically, there is little knowledge about its ability to distinguish gases generated by source rocks deposited in similar sedimentary environments such as coal and coaly mudstone. Therefore, this study was undertaken to investigate position-specific carbon isotopes of 40 propane samples from 15 coal-type gas accumulations across four basins in China (Sichuan, Ordos, Qaidam, and Songliao); additionally, clumped isotopologues of methane samples were also analyzed. These coal systems cover a wide range of thermal maturity (from marginally mature to over-mature) at various age strata from the Permian, Triassic, and Jurassic periods, to the Cretaceous period. Our results revealed that propane generated from coal and coaly mudstone differed greatly in intramolecular isotope compositions despite having similar bulk δ13C3 values. Propane generated from coaly mudstone at a wide range of maturity had relatively more stable δ13C values in both the central (δ13Ccental) and terminal carbons (δ13Cterminal), near the theory generation line of chain-alkane cracking in the plot of δ13Cterminal vs. δ13Ccental. However, propane generated from coal had higher stable δ13Cterminal values and lower δ13Ccentral values that progressively increased with maturity. Under cooling-down conditions, propane from over-mature natural gases became extremely 13C-depleted in both the terminal and central positions, with Δ13Ccentral (δ13Ccentral minus δ13Cterminal) values being as low as –10‰, suggesting a partial origin of methane polymerization. Two propane samples from Cretaceous brown sandstone in the Songliao Basin exhibited an increase in both central and terminal carbons, suggesting that they may have surpassed chemical oxidation owing to high-valence Fe(Mn) oxides. These results indicate that intramolecular isotopes of propane can effectively differentiate dominant gas sources in a coal system with coal or coaly mudstone, as well as easily identify isotopic fractionation caused by post-generation processes, such as methane polymerization, mixing and chemical oxidation.

Rhodium(III)-Catalyzed Remote Hydroamidation of Internal Alkenes via Chain Walking.

Hydroamination of terminal alkenes represents a powerful and well-established way to introduce nitrogenous functionality to feedstock chemicals. Remote hydroamination reactions are far less known, and represent a way to functionalize unactivated C(sp3) centers distal to the site of the alkene. These transformations commonly take place via metal hydride-mediated chain walking, and as such, regioselectivity can be challenging. The remote introduction of amides is of particular interest due to their prevalence in pharmaceuticals. Herein we report a Rh(III)-catalyzed hydroamidation procedure to functionalize the terminal position of internal alkenes, using dioxazolones as amidation reagents and i-PrOH as a hydride source. The reaction proceeds with high yield and regioselectivity, and tolerates a variety of functionality. Regioconvergent synthesis of a single linear amide from a mixture of isomeric alkenes is demonstrated. Key to the development of this reaction was determining that inorganic bases poison the catalyst, and identifying a suitable trialkylamine replacement.

Morphological and molecular identification of java barb (Barbonymus gonionotus) from East Java Province

This study aims is compare the identification of Java barb fish (Barbonymus gonionotus) in East Java Province by morphometric and molecular identification. Molecular identification was conducted using mitochondrial DNA based on the Cytochrome Oxidase Sub Unit I (COI) region. Java barb fish samples were collected from various regions in East Java Province including Gresik, Mojokerto, Madiun, Malang, and Banyuwangi. The identification results by morphological and molecular methods showed the same results, namely Barbonymus gonionotus. Based on the morphological identification, Barbonymus gonionotus has a long and flat body shape with a raised back, terminal mouth position, silver body colour with a darker dorsal area, dorsal fin shape with weakly hardened rays, and homocercal caudal fin shape. The morphometric measurements of Java barb fish using the one-way ANOVA test showed that the five locations differed significantly. The results of the molecular research showed that all java barb fish sequences were successfully amplified with the COI gene (648 bp). The BLASTN results show the percentage identity ranges from 99.85-100%.

Active-Time Reduction of Base Stations for Energy Reduction Using Estimated Terminal Position via Wireless-Communication Signals

Active-Time Reduction of Base Stations for Energy Reduction Using Estimated Terminal Position via Wireless-Communication Signals

Cross-Layer Feature Fusion and Decentration Aberration Correction of Circular Points for Automated Guided Vehicle Terminal Positioning

Cross-Layer Feature Fusion and Decentration Aberration Correction of Circular Points for Automated Guided Vehicle Terminal Positioning

Effect of substituents on the performance of N-carbazolyl double benzylidene ketones in visible/NIR light one/two-photon polymerization

Developing high-performance photoinitiation systems with high sensitivity is of great significance in one/two-photon polymerization. Especially, photoinitiators with rapid photobleaching effects, deep curing abilities and potential for two-photon lithography have great commercial prospects. However, such photoinitiators often require complex organic synthesis, thus having relatively limited varieties. Double benzylidene ketone is widely used as a high-performance dye and can be constructed through a one-step classical aldol condensation reaction. The optimization of its structure often involves introducing extended conjugated structures or different terminal substituents. However, the synergistic impacts of side substituents with different electron effects are rarely studied. Here, six novel carbazolyl double benzylidene ketones with tert-butyl on the terminal position and F atom or N, N-dimethylamino groups substituted at the side position on conjugated structures are designed and prepared to explore the structure–activity relationships. Notably, results show that introducing electron-donating groups at both positions can effectively induce a redshift in the absorption spectra of molecules, and the introduction of an electron-withdrawing F atom on the side position induces impressive photobleaching during photopolymerization under visible LED irradiation. Moreover, CZs/MDEA with PETA exhibit fast writing speed and excellent nano-patterning capability under 780 nm laser in two-photon polymerization (TPP) and have potential applications in 3D microfabrication technologies.

The Electronic Structure and Stability of Ti2SnC/Ag Interface Studied by First‐Principles Calculations

AbstractIn this paper, the electronic properties, the adhesive energy, and the interface energy of the MAX phase Ti2SnC(0001)/Ag(111) interface are systematically investigated using first principles based on density functional theory. Four different terminations of Ti2SnC(0001) are considered, and 16 different Ti2SnC(0001)/Ag(111) interface configurations are obtained by varying the stacking positions of the atoms. After calculating the electronic structure, adhesion work, and interface energy of these interface model interfaces with the same terminal but different atomic positions, it is found that the interface of the same terminal has a very limited effect on the interface bonding of the interface model by changing the stacking order of the interface atomic layer. By comparing the adhesion work and interface energy of 16 interface models, it is found that the HCP2 configuration of C‐Ti2SnC(0001)/Ag(111)interface structure has the highest adhesion work and the lowest interface energy. The larger the adhesion work is, the stronger the bonding between the interface atoms is. Meanwhile, the smaller the interface energy (positive value) is, the more stable the interface is. By calculating the electronic structure of the interface, the accuracy of the above results is further verified after analyzing the partial density of states (PDOS) and charge density difference of the interface.

Antigenic and Structural Properties of the Lipopolysaccharide of the Uropathogenic Proteus mirabilis Dm55 Strain Classified to a New O85 Proteus Serogroup.

The aim of the study was the serological and structural characterization of the lipopolysaccharide (LPS) O antigen from P. mirabilis Dm55 coming from the urine of a patient from Lodz. The Dm55 LPS was recognized in ELISA only by the O54 antiserum, suggesting a serological distinction of the Dm55 O antigen from all the 84 Proteus LPS serotypes described. The obtained polyclonal rabbit serum against P. mirabilis Dm55 reacted in ELISA and Western blotting with a few LPSs (including O54), but the reactions were weaker than those observed in the homologous system. The LPS of P. mirabilis Dm55 was subjected to mild acid hydrolysis, and the obtained high-molecular-mass O polysaccharide was chemically studied using sugar and methylation analyses, mass spectrometry, and 1H and 13C NMR spectroscopy, including 1H,1H NOESY, and 1H,13C HMBC experiments. The Dm55 O unit is a branched three-saccharide, and its linear fragment contains α-GalpNAc and β-Galp, whereas α-GlcpNAc occupies a terminal position. The Dm55 OPS shares a disaccharide epitope with the Proteus O54 antigen. Due to the structural differences of the studied O antigen from the other described Proteus O polysaccharides, we propose to classify the P. mirabilis Dm55 strain to a new Proteus O85 serogroup.

Configuration of the Scandinavian Ice Sheet in southwestern Norway during the Younger Dryas

The extent of the Scandinavian Ice Sheet in southwestern Norway is precisely located during the well-characterized Younger Dryas re-advance. However, the thickness of the ice sheet is less well constrained inland from the terminal position. Some exceptions include lateral moraines traced inland and up to 1000 m a.s.l. along Hardangerfjorden. Here, we apply 10Be dating in two areas: (1) bedrock and boulders in the high-relief landscapes near the Younger Dryas margin around the Bergen urban area, and (2) boulders from an upland 1600 m a.s.l. much farther (120 km) inland. We find that coastal summits ranging from ~400 to ~680 m a.s.l. and located only ~10–15 km up-flow from the ice margin, were covered by the Scandinavian Ice Sheet during the Younger Dryas. The scatter in the 10Be age population of 22 boulder samples is best explained by isotopic inheritance owing to inefficient subglacial erosion during the foregoing glaciation. Most of the 11 bedrock samples also exhibit inheritance, pointing to the source of inheritance in boulders and implying inefficient subglacial erosion during the last glaciation even in valley-bottoms near Bergen. Regional glacial striae compilations suggest that ice flow during maximum Younger Dryas ice-sheet configurations was for the most part cross-valley, with potentially low basal slip rates. Five new 10Be ages from the inland site help to constrain ice height far inland. We combine these new results with prior information to generate a cross profile of the Younger Dryas ice sheet in southern Norway.

Tyrosinase inhibitory peptides: Structure-activity relationship study on peptide chemical properties, terminal preferences and intracellular regulation of melanogenesis signaling pathways

BackgroundBioactive peptides have gained attention as potential alternatives to chemical-based skin lightening agents. Based on literature search, the reported articles focused mainly on the sources and preparation methods of tyrosinase inhibitory peptides and there is lacking information regarding the structure-activity relationship (SAR) between peptide property and tyrosinase inhibition. It was hypothesized that peptide properties such as hydrophobicity/hydrophilicity and the amino acid type and position/arrangement at the terminal positions could affect peptide mode of binding hence result in various degrees of tyrosinase inhibition. MethodsIn this study, the sequences of 128 tyrosinase inhibitory peptides were collected from peer-reviewed articles. The hydrophobicity/hydrophilicity property and the amino acid profile of peptides at the N- and C-terminals were analyzed using bioinformatics tools. Molecular docking analysis was employed to further elucidate the roles of reactive amino acids in tyrosinase-peptide binding interactions. The peptide-regulated intracellular melanogenesis pathways were also compiled and discussed. ResultsIt was found that hydrophobic and/or polar neutral properties may facilitate or stabilize peptide binding with tyrosinase. Moreover, short peptides featuring a cysteine and tyrosine at the N- and C- terminal ultimate positions tend to bind to the active site of tyrosinase whereas positively charged amino acid such as arginine at the N-terminal does not favor peptide binding to tyrosinase. ConclusionsThese findings provide detailed explanation on how peptide/amino acid structures are related and what function they play in tyrosinase inhibition. It could also inspire researchers to account for tyrosinase-peptide SAR and the underlying anti-melanogenesis mechanisms in formulating peptide-based treatments or strategies against skin hyperpigmentation.

A fully bio‐based monomer derived from undecylenic acid, glycerol, and CO2 useful for the synthesis of polyhydroxyurethanes

AbstractUndecylenic acid, glycerol, and CO2 were used as building blocks for obtaining a fully bio‐based carbonated monomer, useful for polyurethanes. The functionality of the monomer was close to 3 cyclic carbonates/mol, located in terminal positions. In a first stage, a synthetic triglyceride was obtained with 99% selectivity by esterification of glycerol and undecylenic acid at 160°C. The triglyceride was then epoxidized using H2O2 and Amberlyst 15 or Amberlite IR‐120 acidic exchange resins at 57°C. The selectivity to epoxide was kept constant at 98% using Amberlite IR‐120. Terminal cyclic carbonates were then inserted through epoxide moieties under mild conditions by the chemical fixation of CO2 at 80°C and 6 MPa in 6 h. A complete conversion was obtained in 6 h reaction while the selectivity to carbonate groups was near to 99% during all the reaction time. An elastomeric polyhydroxyurethane was obtained by aminolysis of the carbonated monomer with ethylenediamine at 70°C, affording a Young's modulus of 22.6 MPa and Tg of −15.2°C. The material showed a good thermal stability below 240°C.