Unstable Coordination Research Articles

Theoretical insights on oxygen electrode reactions of YNxC4-x@Gra with hydroxylation effect

The oxygen electrode reactions (ORR/OER) are the key to electrochemical storage and conversion technologies. In this study, the bifunctional electrocatalytic mechanisms of YNxC4-x@Gra with hydroxylation effect were discussed extensively. Firstly, the configurations with N coordination have good stability. Secondly, YN1C3/N2C2hex@Gra with unstable coordination environment break the scale relationships between adsorption intermediates and exhibit outstanding OER performance with ηOER of 0.45 V and 0.46 V. Thirdly, YN2C2oppo/N2C2pen/N3C1OH@Gra with stable coordination environment demonstrate excellent bifunctional activity with ηORR of 0.48 V, 0.54 V, and 0.53 V and ηOER of 0.71 V, 0.73 V, 0.63 V. Forth, for catalysts with stable coordination environments, there are scale relationships between the adsorption of intermediates, and thus volcanic curves were constructed. Finally, the d-electron number was introduced to predict catalytic performance, saving time and computative costs for screening potential catalyst configurations. All in all, YNxC4-x@Gra catalysts are potential oxygen electrode bifunctional electrocatalysts.

A novel strategy for fabrication of antistatic and antibacterial fabric via layer-by-layer self-assembly

Metal ions coordination modification is an efficient method for preparing antibacterial textile, but there are still problems such as unstable coordination and poor antibacterial durability. Herein, a copper ion-crosslinked sodium alginate-graphene oxide (Cu2+/SA-GO) structure was designed and constructed on the nylon 66 fabric with polydopamine (PDA)-mediated layer-by-layer self-assembled technology. The cross-linked network structure of Cu2+ and SA-GO not only improved the loading fastness of Cu2+ but also promoted the saltwater resistance of the SA-based coatings. Concurrently, the PDA mediated the layer self-assembly process and facilitated the durability of the coating simultaneously. The results showed that the antibacterial ratio of the prepared fabric against Staphylococcus aureus and Escherichia coli were still up to 99.9 % after 30 times washing. In addition, the modified fabric exhibited good antistatic property with a surface resistivity of about 108 Ω.cm, which was attributed to the strong hydrophilic property of the self-assembled coating. This work may provide a new method for the efficient preparation of long-lasting antibacterial fabrics.

줄넘기 시 템포가 협응에 미치는 영향

The purpose of this study was to compare and analyze the effect of tempo on coordination during jump rope. Thirty healthy adult males participated. The task was to jump rope single under with both feet synchronize with metronome tempo(80, 100, 120, 140, 160 bpm). The joint angles and angular velocities of wrist, elbow, shoulder, hip, knee, and ankle were calculated using data stably performed 5 times consecutively among the data performed 10 times in a row synchronize with metronome tempo. And angle-angle diagram, phase plane portraits, and correlation analysis were analyzed using each joint angle and angular velocity. The results of this study were as follows: First, The angle-angle diagrams show that the joint angles decrease as getting faster the tempo. In the wrist-shoulder and hip-ankle diagrams, coupled coordination was observed as getting faster the tempo. Second, In the phase plane portraits, the angular-angular velocity of all joints showed a convex shape. As getting faster the tempo, the angular velocities of the shoulders, hips, and knees decreased. Third, Elbow-shoulder, hip-knee, knee-ankle, and hip-ankle correlation coefficients were high. It was found that the correlation coefficient of hip-knee and hip-ankle decreased as getting faster the tempo. In conclusion, Wrist, elbow, and ankle joints played a more important role in jumping rope than the shoulder, knee, and hip joints. And, When the tempo of jumping rope was 120 bpm or higher, a stable coordination pattern appeared, but when the jumping rope was slowed at a slow tempo, an unstable coordination pattern was observed.

Third party stabilization of unstable coordination in systems of coupled oscillators

The Haken-Kelso-Bunz (HKB) system of equations is a well-developed model for dyadic rhythmic coordination in biological systems. It captures ubiquitous empirical observations of bistability – the coexistence of in-phase and antiphase motion – in neural, behavioral, and social coordination. Recent work by Zhang and colleagues has generalized HKB to many oscillators to account for new empirical phenomena observed in multiagent interaction. Utilising this generalization, the present work examines how the coordination dynamics of a pair of oscillators can be augmented by virtue of their coupling to a third oscillator. We show that stable antiphase coordination emerges in pairs of oscillators even when their coupling parameters would have prohibited such coordination in their dyadic relation. We envision two lines of application for this theoretical work. In the social sciences, our model points toward the development of intervention strategies to support coordination behavior in heterogeneous groups (for instance in gerontology, when younger and older individuals interact). In neuroscience, our model will advance our understanding of how the direct functional connection of mesoscale or microscale neural ensembles might be switched by their changing coupling to other neural ensembles. Our findings illuminate a crucial property of complex systems: how the whole is different than the system’s parts.

Room-Temperature Structure of Xylitol-Bound Glucose Isomerase by Serial Crystallography: Xylitol Binding in the M1 Site Induces Release of Metal Bound in the M2 Site.

Glucose isomerase (GI) is an important enzyme that is widely used in industrial applications, such as in the production of high-fructose corn syrup or bioethanol. Studying inhibitor effects on GI is important to deciphering GI-specific molecular functions, as well as potential industrial applications. Analysis of the existing xylitol-bound GI structure revealed low metal occupancy at the M2 site; however, it remains unknown why this phenomenon occurs. This study reports the room-temperature structures of native and xylitol-bound GI from Streptomyces rubiginosus (SruGI) determined by serial millisecond crystallography. The M1 site of native SruGI exhibits distorted octahedral coordination; however, xylitol binding results in the M1 site exhibit geometrically stable octahedral coordination. This change results in the rearrangement of metal-binding residues for the M1 and M2 sites, the latter of which previously displayed distorted metal coordination, resulting in unstable coordination of Mg2+ at the M2 site and possibly explaining the inducement of low metal-binding affinity. These results enhance the understanding of the configuration of the xylitol-bound state of SruGI and provide insights into its future industrial application.

Rational design of metal-organic frameworks to deliver methotrexate for targeted rheumatoid arthritis therapy

Methotrexate (MTX) has been used as an anchor drug for the treatment of rheumatoid arthritis (RA), while the patients with chronic MTX administration suffer from severe side-effects. To this end, targeted delivery of MTX by nanomedicine has attracted great interest. In this work, we aimed to employ metal-organic frameworks (MOFs) as nanocarrier to deliver MTX by virtue of its facile and green preparation and exceptionally high drug loading. While MTX could be easily and effectively loaded via different MOF construction strategies, such as direct coordination, physical encapsulation, and covalent conjugation, we found that most of the MTX loading MOFs showed premature and burst drug release, attributable to the unstable coordination between MTX and metals. To address this issue, we rationally designed the MOFs by conjugating MTX with tannic acid (TA) at 2:1 M ratio and then coordinating with ferric ion (Fe3+), followed by surface modification of hyaluronic acid (HA). The resulting MOFs achieved ultra-high drug loading (45%) and sustained drug release, and could selectively recognize the diseased cells for anti-inflammatory effect. The in vivo therapeutic evaluation suggested that the MOFs could enhance the anti-rheumatic activity of MTX while minimizing its toxic effects by targeted drug delivery, resulting in improved therapeutic index. This work provides a biocompatible nano-platform to deliver MTX for RA treatment, and importantly, calls for special attention to the gap between MOFs design and their biological applications, and the gap needs to be filled by careful evaluation of in vivo stability and burst drug release.

Early learning differences between intra- and interpersonal interlimb coordination.

Intrinsic coordination patterns exist between limbs such that 1) coordination at these states is inherently stable, 2) any other pattern requires learning to produce, and 3) this learning is subject to interference from a systemic bias towards intrinsic patterns. The dynamics that govern intrapersonal interlimb coordination also govern interpersonal coordination. However, intrapersonal coordination exhibits greater coupling strength and thus more stable intrinsic dynamics than interpersonal coordination. Because the strength of intrinsic coordination tendencies has consequences for learning coordination patterns, the differences in coupling strength between intra- and interpersonal coordination should impact the ability to perform new coordination patterns via greater or less interference from intrinsic dynamics. This was investigated by measuring participants' performance as they learned a new coordination pattern alone (intrapersonal) or in pairs (interpersonal). Participants were implicitly tasked with learning the pattern as they separately controlled the vertical and horizontal position of an on-screen cursor to trace a circling target. We observed better performance of dyads on first trial and steeper learning trajectories for individuals. Overall, these results indicate that individuals experienced greater interference from stronger intrinsic coordination dynamics during early learning but could overcome this interference and achieve similar performance to that of dyads with very little practice.

Manganese–Fluorouracil Metallodrug Nanotheranostic for MRI-Correlated Drug Release and Enhanced Chemoradiotherapy

For cancer therapy, drug delivery systems are often limited by insufficient drug loading capacity, which usually results in systemic toxicity and heavy metabolic burden to excrete the carriers. Her...

Adaptation to unstable coordination patterns in individual and joint actions.

Previous research on interlimb coordination has shown that some coordination patterns are more stable than others, and function as attractors in the space of possible phase relations between different rhythmic movements. The canonical coordination patterns, i.e. the two most stable phase relations, are in-phase (0 degree) and anti-phase (180 degrees). Yet, musicians are able to perform other coordination patterns in intrapersonal as well as in interpersonal coordination with remarkable precision. This raises the question of how music experts manage to produce these unstable patterns of movement coordination. In the current study, we invited participants with at least five years of training on a musical instrument. We used an adaptation paradigm to address two factors that may facilitate producing unstable coordination patterns. First, we investigated adaptation in different coordination settings, to test the hypothesis that the lower coupling strength between individuals during joint performance makes it easier to achieve stability outside of the canonical patterns than the stronger coupling during individual bimanual performance. Second, we investigated whether adding to the structure of action effects may support achieving unstable coordination patterns, both intra- and inter-individually. The structure of action effects was strengthened by adding a melodic contour to the action effects, a measure that has been shown to improve the acquisition of bimanual coordination skills. Adaptation performance was measured both in terms of asynchrony and variability thereof. As predicted, we found that producing unstable patterns benefitted from the weaker coupling during joint performance. Surprisingly, the structure of action effects did not help with achieving unstable coordination patterns.

Comparison of Lumbopelvic Coordination between Trunk Flexion and Extension

Lumbopelvic coordination describes the relative contributions of lumbar and pelvis to the total trunk flexion/extension motion, which has been identified as a major influential factor to spinal loading. The current study investigated the differences in lumbopelvic coordination between trunk flexion and extension. Thirteen subjects performed pace-controlled trunk flexion/extension motions in the sagittal plane while lumbopelvic continuous relative phase and phase variability were quantified. The results demonstrated that compared with trunk extension, lumbopelvic continuous relative phase and phase variability were 28% and 117% greater in trunk flexion motion, respectively, which indicated a more anti-phase and unstable coordination pattern. Quantifying these coordination patterns helps identifying abnormal patterns and serves as normative benchmarks during low back pain rehabilitation.

Investigating the effects of movement speed on the lumbopelvic coordination during trunk flexion

Movement speed during trunk flexion has long been reported to affect task performance and biomechanical responses. The current study investigated how movement speed changed lumbopelvic coordination, especially lumbopelvic continuous relative phase and phase variability during trunk flexion. Eighteen subjects executed a paced trunk flexion routine over time periods of 3, 7, 11 and 15seconds. The results demonstrated that compared with the 3-s condition, lumbopelvic continuous relative phase was 98.8% greater in the 15-s condition, indicating a more anti-phase coordination pattern. This pattern is suggested to mitigate the increased spinal loading associated with the longer duration of muscle exertion. Additionally, phase variability was 18.8% greater in the 15-s trials than the 3-s trials, such an unstable coordination pattern is likely caused by the more active neuromuscular control. Findings of this study provide important information about the effects of movement speed on lumbopelvic coordination during trunk flexion.

Continuous scanning trials:Transitioning through the attractor landscape

Bimanual 1:1 coordination patterns other than in-phase (0°) and anti-phase (180°) have proven difficult to perform even with extended practice. The difficulty has traditionally been attributed to phase attraction that draws the coordination between the limbs towards the bimanual patterns of in-phase and anti-phase and variability associated with the activation and associated proprioceptive signals of non-homologous muscles via crossed and uncrossed cortical pathways. However, recent experiments have demonstrated that a wide range of relative phase and multi-frequency coordination patterns can be effectively produced with only a few minutes of practice when Lissajous or online relative phase information is provided. The present experiment was designed to determine if participants provided Lissajous feedback comprised of continuously transitioning relative phase goals could be effectively performed as the participant navigates through the attractor landscape. The results clearly indicated that participants can effectively produce a large range of supposedly unstable coordination patterns (between 0° and 180° in 1° increments) after only a few minutes of practice. These findings clearly indicate that the perception-action system is fully capable of effectively producing and transitioning through a wide range of bimanual coordination patterns and that the reason for the failure to produce these patterns in previous experiments resides in the perceptual information and attentional requirements typically found in experimental testing environments.

Exercise to Improve Mobility in Healthy Aging.

Biological aging inevitably affects every individual, no matter what their color of skin, country of origin, level of education, and socio-economic status is. Intuitively, we associate aging with old age. However, aging encompasses more than senescence. In fact, the process begins at conception and continues throughout the lifespan, with marked physiological and performance changes occurring for some reason after age 60 years. Aging is a process or group of processes occurring in living organisms that with the passage of time leads to a loss of adaptability, functional impairment, and eventually death [1]. Healthy aging is a desirable path that is worth pursuing for every individual. Factors that determine healthy or successful aging are avoiding disease (e.g., obesity), engagement with life (e.g., social activities), maintaining high cognitive and physical function through, for instance, proper diet, and sufficient physical activity [1]. The American College of Sports Medicine and the American Heart Association have provided recommendations on the types and amounts of physical activity needed to improve and maintain health in older adults [2]. With this purpose in mind, seniors are advised to perform physical activity at a moderate intensity that results in aerobic metabolism for a minimum of 30 min on 5 days each week or vigorous-intensity aerobic activity for a minimum of 20 min on 3 days each week. To maintain the flexibility necessary for regular physical activity and daily life, older adults should perform activities that maintain or increase flexibility on at least 2 days each week for at least 10 min each day. To reduce the risk of injury due to falls, community-dwelling older adults at substantial risk of falls should perform exercises that maintain or improve balance. In addition, at least twice each week older adults should perform muscle-strengthening activities using the major muscles of the body to maintain or increase muscular strength and endurance [2]. The German Research Foundation provided support for a series of workshops that took place in Potsdam, Freiburg, and Kassel between October 2013 and September 2014 (MU 3327/2-1). International experts discussed current knowledge of how age affects motor performance throughout the lifespan and how exercise interventions could improve motor performance in older adults, delay the onset and progression of mobility disability, and promote healthy aging. To complement already existing physical activity guidelines, this themed issue of Sports Medicine contains systematic literature reviews and meta-analyses that provide evidence-based overviews of current knowledge concerning the efficacy of exercise interventions with a focus on seniors. Four of seven papers focus on the intervention effects of strength training using unstable surfaces, resistance training, power training, coordination training, and balance training on measures of balance, strength, power, and mobility in cohorts across the lifespan with a focus on older adults (Behm et al., Borde et al., Hortobagyi et al., Lesinski et al). Two papers describe the dose-response relationships following resistance and balance training in older adults (Borde et al., Lesinski et al.). This is new and important evidence-based information for practitioners and therapists seeking to design and implement effective exercise programs to counteract dynapenia, sarcopenia, and mobility disability in seniors. Further, two papers analyze how task difficulty affects responses to balance perturbations in older adults (Bohm et al.) and cognitive-motor dual tasking across the lifespan (Ruffieux et al.), with a perspective on intervention design. Finally, Muehlbauer et al. examine the relationship between measures of balance and leg strength/power across the lifespan in an effort to provide information that facilitates better-informed exercise prescription. The consistent message from this wealth of up-to-date information is that spontaneous physical activity and systematic exercise delivered in a variety of forms can increase motor performance independent of age, slow the progression of mobility disability, and most likely improve health in old age. As part of their efforts to promote healthy aging, practitioners, healthcare professionals, and policy makers can use this new knowledge to recommend and urge seniors to become and remain physically active.

Calcium Phosphate Cement Reinforced by Nanocrystalline Cellulose

The aim of this study is to investigate the effect of nanocrystalline cellulose (NCC) with favorable mechanical properties on the compressive strength of calcium phosphate cement (CPC). Compressive test, Gilmore needle test, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to analyze the physicochemical properties of CPC influenced by different contents of NCC. Scanning electron microscope (SEM) and fluorescence microscope were used to observe the morphologies of CPC and the dispersity of labeled-NCC in CPC, respectively. NCC significantly increased the compressive strength of CPC up to about 27 MPa when the content of NCC was 2%. Setting times of CPC were prolonged with increased NCC, but still met the clinical requirements when the content of NCC was not more than 2%. XRD and XPS indicated that the combination of NCC with Ca could form unstable coordination compound and NCC promoted the dissolution and conversion of dicalcium phosphate dehydrate (DCPD) and CaCO3. SEM showed that CPC became denser with fewer pores and cracks by addition of NCC. Fluorescence microscope demonstrated the homogeneous dispersion of labeled-NCC in CPC. 第 3期 赵军胜, 等: 纳米晶体纤维素增强磷酸钙骨水泥的研究 319

Facile preparation of ion-imprinted composite film for selective electrochemical removal of nickel(II) ions.

A facile unipolar pulse electropolymerization (UPEP) technique is successfully applied for the preparation of ion-imprinted composite film composed of ferricyanide-embedded conductive polypyrrole (FCN/PPy) for the selective electrochemical removal of heavy metal ions from wastewater. The imprinted heavy metal ions are found to be easily removed in situ from the growing film only by tactfully applying potential oscillation due to the unstable coordination of FCN to the imprinted ions. The obtained Ni(2+) ion-imprinted FCN/PPy composite film shows fast uptake/release ability for the removal of Ni(2+) ions from aqueous solution, and the adsorption equilibrium time is less than 50 s. The ion exchange capacity reaches 1.298 mmol g(-1) and retains 93.5% of its initial value even after 1000 uptake/release cycles. Separation factors of 6.3, 5.6, and 6.2 for Ni(2+)/Ca(2+), Ni(2+)/K(+), and Ni(2+)/Na(+), respectively, are obtained. These characteristics are attributed to the high identification capability of the ion-imprinted composite film for the target ions and the dual driving forces resulting from both PPy and FCN during the redox process. It is expected that the present method can be used for simple preparation of other ion-imprinted composite films for the separation and recovery of target heavy metal ions as well.

"A Very Soft or Long Attack and Release" or Heyyyyy

Amalle Dublon's piece takes up extensity — the drawing out of certain sounds in verbal speech — as phonic gesture that exceeds the temporal (and we might argue productive) regulations of merely representative, coded speech. In doing so, extensity creates what Dublon describes as a kind of anticipatory penumbra that halos and holds the unstable coordination of mutual respondents. Here, Dublon's work seemingly provides an entry point into imagining queer community-formation as project made possible by phonic excess.

Effect of Robot–Child Interactions on Bilateral Coordination Skills of Typically Developing Children and a Child With Autism Spectrum Disorder: A Preliminary Study

Background:Coordination develops gradually over development with younger children showing more unstable coordination patterns compared to older children and adults. In addition, children with Autism Spectrum Disorders (ASDs) display significant coordination impairments. In the current study, we examined whether robot–child interactions could improve bilateral coordination skills of typically developing (TD) children and one child with ASD.Method:Fourteen TD children between four and seven years of age and an 11-year-old child with ASD performed dual-limb and multilimb actions within a solo and social context during a pre- and posttest. Between the pre- and posttests, eight training sessions were offered across four weeks during a robot imitation context involving karate and dance actions.Results:Younger TD children and the child with ASD improved their solo coordination whereas the older TD children increased their social coordination.Limitations:This preliminary study lacked a control group.Conclusions:Robot–child interactions may facilitate bilateral coordination and could be a promising intervention tool for children with ASDs.

Syntheses, structures, and spectroscopy of mono- and polynuclear lanthanide complexes containing 4-acyl-pyrazolones and diphosphineoxide

Lanthanide coordination compounds are important due to their unique luminescence and magnetic properties. Direct synthesis of oligo- and polymeric Ln complexes with a predicted structure is hampered due to high coordination numbers and unstable coordination polyhedra. A «building blocks» strategy for the synthesis of Ln(Q) 3L polymers (Ln = Eu, Tb or Gd; HQ = 1-phenyl-3-methyl-4-RC( O)pyrazol-5-one in general, in detail HQ S, R = thienyl; HQ CP: R = cyclopentyl; L = bis(diphenylphosphine)methane dioxide dppMO 2, bis(diphenylphosphine)ethane dioxide dppEO 2, and bis(diphenylphosphine)butane dioxide dppBO 2) has been used: {Ln(Q) 3} mononuclear fragments have been linked by dppXO 2 bridges when X = E or B, while monomeric molecular derivatives have been isolated with dppMO 2. Eighteen new complexes were prepared, 12 of them showing a polymeric nature and 6 being monomers. Three compounds have been structurally characterized, further confirming the hypothesized connectivity where metal centers have been found to exist in LnO 8 square antiprismatic environments. Luminescence properties have been also investigated.

Using scanning trials to assess intrinsic coordination dynamics

Bimanual 1:1 coordination patterns other than in-phase (0°) and anti-phase (180°) have proven difficult to perform even with extended practice. The difficulty has been attributed to phase attraction that draws the coordination between the limbs towards the bimanual patterns of in-phase and anti-phase and variability associated with the activation of non-homologous muscles via crossed and uncrossed cortical pathways. We found participants could very effectively produce a large range of supposedly unstable coordination patterns (between 0° and 180° in 30° increments) after only 3 min of practice when integrated feedback (Lissajous plots) was provided and other perceptual and attentional distractions were minimized. These findings clearly indicate that the perception-action system is fully capable of producing a wide range of bimanual coordination patterns and that the reason for the failure to produce these patterns in previous experiments reside in the perceptual information and attentional requirements typically found in experimental testing environments.

Recent progress in inorganic vibrational spectroscopy.

During the past decade or so, inorganic vibrational spectroscopy has made great strides with the advent of several new experimental techniques. First, the development of the metal isotope technique provided the means to make unequivocal assignments of vibrations in the low frequency region. It is currently a routine practice to obtain metal isotope data whenever definitive assignments of metal-ligand vibrations are required. Second, the matrix isolation technique became accessible to inorganic chemists as a result of the development and marketing of closed cycle helium cryocoolers. By combining various types of ovens with these cryocoolers, inorganic chemists were able to prepare a large number of unstable coordination compounds and measure their vibrational spectra in the matrix isolated state. Third, the development of gas and dye lasers together with double and triple monochromators revolutionized Raman spectroscopy. Nowadays, measurements of Raman spectra are as routine as that of infrared spectra. Resonance Raman spectroscopy is also playing a significant role in understanding the relationship between resonance-enhanced vibrational modes and the nature of excited electronic states involved. The purpose of this article is to review our contributions in these three areas using typical examples.