In-situ-grown silver–polymer framework with coordination complexes for functional artificial tissues

Sensorized actuators are critical to imitate proprio-/exteroception properties of biological neuromuscular systems. Existing add-on approaches, which physically blend heterogeneous sensor/actuator components, fall short of yielding satisfactory solutions, considering their suboptimal interfaces, poor adhesion, and electronic/mechanical property mismatch. Here, we report a single homogeneous material comprising seamless sensing-actuation unification properties at nano-/molecule levels, in which built-in sensing functions originate from the actuator architecture itself. In-situ-grown silver nanoparticles and metal-ligand complexes cooperatively create a silver–polymer framework (SPF) that is stretchable (1200%), conductive (0.076 S/m), and strong (0.76 MPa in-strength). SPF displays concomitant multimodal sensing (mechanical and thermal cues) and sensorized actuation capabilities, which include proprio-deformation and external stimuli perceptions (simultaneous with load-lifting ability up to 3700× of own weight). In view of its human somatosensitive muscular systems imitative functionality, the reported SPFs bode well for use with next generation functional tissues including artificial skins, human-machine interfaces, self-sensing robots, and otherwise dynamic materials.

Mechanosensitive recruitment of stator units promotes binding of the response regulator CheY-P to the flagellar motor

Reversible switching of the bacterial flagellar motor between clockwise (CW) and counterclockwise (CCW) rotation is necessary for chemotaxis, which enables cells to swim towards favorable chemical habitats. Increase in the viscous resistance to the rotation of the motor (mechanical load) inhibits switching. However, cells must maintain homeostasis in switching to navigate within environments of different viscosities. The mechanism by which the cell maintains optimal chemotactic function under varying loads is not understood. Here, we show that the flagellar motor allosterically controls the binding affinity of the chemotaxis response regulator, CheY-P, to the flagellar switch complex by modulating the mechanical forces acting on the rotor. Mechanosensitive CheY-P binding compensates for the load-induced loss of switching by precisely adapting the switch response to a mechanical stimulus. The interplay between mechanical forces and CheY-P binding tunes the chemotactic function to match the load. This adaptive response of the chemotaxis output to mechanical stimuli resembles the proprioceptive feedback in the neuromuscular systems of insects and vertebrates.

Mechanosensitive recruitment of stator units promotes binding of the response regulator CheY-P to the flagellar motor

Reversible switching of the bacterial flagellar motor between clockwise (CW) and counterclockwise (CCW) rotation is necessary for chemotaxis, which enables cells to swim towards favorable chemical habitats. Increase in the viscous resistance to the rotation of the motor (mechanical load) inhibits switching. However, cells must maintain homeostasis in switching to navigate within environments of different viscosities. The mechanism by which the cell maintains optimal chemotactic function under varying loads is not understood. Here, we show that the flagellar motor allosterically controls the binding affinity of the chemotaxis response regulator, CheY-P, to the flagellar switch complex by modulating the mechanical forces acting on the rotor. Mechanosensitive CheY-P binding compensates for the load-induced loss of switching by precisely adapting the switch response to a mechanical stimulus. The interplay between mechanical forces and CheY-P binding tunes the chemotactic function to match the load. This adaptive response of the chemotaxis output to mechanical stimuli resembles the proprioceptive feedback in the neuromuscular systems of insects and vertebrates.

A COVID-19 Rehabilitation Prospective Surveillance Model for Use by Physiotherapists

The long-term sequelae of coronavirus disease 2019 (COVID-19) are only now beginning to be defined, but it is already known that the disease can have direct and indirect impacts mainly on the cardiorespiratory and neuromuscular systems and may affect mental health. A role for rehabilitation professionals from all disciplines in addressing COVID-19 sequelae is recognised, but it is essential that patient assessment be systematic if health complications are to be identified and treated and, if possible, prevented. The aim is to present a COVID-19 prospective surveillance model based on sensitive and easily used assessment tools, which is urgently required. Following the Oxford Centre for Evidence-Based Medicine Level of Evidence Tool, an expert team in cardiorespiratory, neuromuscular and mental health worked via telemeetings to establish a model that provides guidelines to rehabilitation professionals working with patients who require rehabilitation after suffering from COVID-19. A COVID-19 prospective surveillance model is proposed for use by rehabilitation professionals and includes both face-to-face and telematic monitoring components. This model should facilitate the early identification and management of long-term COVID-19 sequelae, thus responding to an arising need.

Somatosensory actuator based on stretchable conductive photothermally responsive hydrogel

Mimicking biological neuromuscular systems’ sensory motion requires the unification of sensing and actuation in a singular artificial muscle material, which must not only actuate but also sense their own motions. These functionalities would be of great value for soft robotics that seek to achieve multifunctionality and local sensing capabilities approaching natural organisms. Here, we report a soft somatosensitive actuating material using an electrically conductive and photothermally responsive hydrogel, which combines the functions of piezoresistive strain/pressure sensing and photo/thermal actuation into a single material. Synthesized through an unconventional ice-templated ultraviolet–cryo-polymerization technique, the homogenous tough conductive hydrogel exhibited a densified conducting network and highly porous microstructure, achieving a unique combination of ultrahigh conductivity (36.8 milisiemens per centimeter, 103-fold enhancement) and mechanical robustness, featuring high stretchability (170%), large volume shrinkage (49%), and 30-fold faster response than conventional hydrogels. With the unique compositional homogeneity of the monolithic material, our hydrogels overcame a limitation of conventional physically integrated sensory actuator systems with interface constraints and predefined functions. The two-in-one functional hydrogel demonstrated both exteroception to perceive the environment and proprioception to kinesthetically sense its deformations in real time, while actuating with near-infinite degrees of freedom. We have demonstrated a variety of light-driven locomotion including contraction, bending, shape recognition, object grasping, and transporting with simultaneous self-monitoring. When connected to a control circuit, the muscle-like material achieved closed-loop feedback controlled, reversible step motion. This material design can also be applied to liquid crystal elastomers.

Evaluation of the pharmacological properties of piscine venoms from both Lionfish (Pterois) and Stonefish (Synanceja)

Background:: For the past 70 years, the focus of research is towards the search for poisons and toxins found in venomous and poisonous organisms which is purely directed towards the pharmacological properties of the toxins. In the research of finding novel compounds in pharmaceutical research, the identified source was the piscine venom. Objective:: Scorpanidae family was considered the most venomous of all. The toxins isolated from stonefish and lionfish are responsible for the effects caused in cardiovascular and neuromuscular systems and also in causing cytolytic activities. The main objective of the review is to study the mechanism of the stone fish venom and portray its benefits in the field of drug discovery. Methods:: A study on the mechanism of stone fish venom was carried out by inducing cardiovascular endothelium. The release of neurotransmitter signals thus leads to the depolarisation of cell membrane by the formation of pores in the cell membrane in neuromuscular system of rabbits, porcine artery, mice and rats. Lionfish venom in cross reactivity with the results evolved from a stonefish venom activity. The presence of enzymatic hyaluronidase in the primary structures of lionfish has evolved from stonefish and their anticancer potential has also been demonstrated for the benefits of drug discovery as they possess biological and chemical activity. Conclusion:: This review depicts an overview on the pharmacological activities of lionfish venom in comparison with the stonefish venom and their purpose on applications for future research in drug discovery.

Design of a High-Speed Prosthetic Finger Driven by Peano-HASEL Actuators

Current designs of powered prosthetic limbs are limited by the nearly exclusive use of DC motor technology. Soft actuators promise new design freedom to create prosthetic limbs which more closely mimic intact neuromuscular systems and improve the capabilities of prosthetic users. This work evaluates the performance of a hydraulically amplified self-healing electrostatic (HASEL) soft actuator for use in a prosthetic hand. We compare a linearly-contracting HASEL actuator, termed a Peano-HASEL, to an existing actuator (DC motor) when driving a prosthetic finger like those utilized in multi-functional prosthetic hands. A kinematic model of the prosthetic finger is developed and validated, and is used to customize a prosthetic finger that is tuned to complement the force-strain characteristics of the Peano-HASEL actuators. An analytical model is used to inform the design of an improved Peano-HASEL actuator with the goal of increasing the fingertip pinch force of the prosthetic finger. When compared to a weight-matched DC motor actuator, the Peano-HASEL and custom finger is 10.6 times faster, has 11.1 times higher bandwidth, and consumes 8.7 times less electrical energy to grasp. It reaches 91% of the maximum range of motion of the original finger. However, the DC motor actuator produces 10 times the fingertip force at a relevant grip position. In this body of work, we present ways to further increase the force output of the Peano-HASEL driven prosthetic finger system, and discuss the significance of the unique properties of Peano-HASELs when applied to the field of upper-limb prosthetic design. This approach toward clinically-relevant actuator performance paired with a substantially different form-factor compared to DC motors presents new opportunities to advance the field of prosthetic limb design.

THE USE OF COMPREHENSIVE DIAGNOSTICS FOR ASSESSING THE FITNESS OF WEIGHTLIFTERS

Aim. The purpose of the article is to develop a method of comprehensive diagnostics for assessing the functional status of weightlifters. Materials and methods. The study involved 14 highly skilled weightlifters at 2 pre-competitive stages of training. The parameters of cardiovascular (heart rate, blood pressure, Gench test), central nervous (differentiation of large and small muscular efforts, statokinetic stability of the body, the speed of sensorimotor reactions), neuromuscular (muscular response threshold) systems were determined. Power capabilities of athletes were investigated. On the 3rd minute of recovery after load blood sampling for lactate analysis was carried out. Results. The results obtained show that at 1 precompetitive stage of training when special exercises are primarily used athletes demonstrate the initial symptoms of fatigue (cardiovascular system and a number of indicators of the central and neuromuscular systems) along with the high level of development of power qualities and high anaerobic capacity. When re-testing athletes during their preparation for the most important competitions provided by a versatile training program, the functional status of the body systems was considered to be high. Conclusion. A comprehensive study allows assessing the fitness of weightlifters from a systemic perspective. The use of the developed method allowed to prove new approaches to training of highly skilled weightlifters.

Enhancement of hypothalamic-pituitary activity in male athletes: evidence of a novel hormonal mechanism of physical conditioning

Background Exercise is known to induce multiple beneficial conditioning processes. Conversely, although exercise may generate several hormonal effects, an intrinsic hormonal conditioning process has not been reported. In the Endocrine and Metabolic Responses on Overtraining Syndrome (EROS) study, we observed inherent and independent conditioning processes of the hypothalamic-pituitary axes in athletes. Our objective is to describe the theory of the novel hormonal conditioning mechanism using the findings from the EROS study. Methods In this cross-sectional study, we selected 25 healthy athletes (ATL) and 12 non-physically active healthy controls (NPAC), 18–50 years old, males, with BMI 20–30 kg/m2, with similar baseline characteristics, who underwent gold-standard exercise-independent tests: cosyntropin stimulation test (CST) and insulin tolerance test (ITT), to evaluate cortisol response to CST, and ACTH, cortisol, GH, and prolactin responses to an ITT. Results Responses to ITT were significantly earlier and higher in ATL than NPAC for cortisol [Mean ± SD: 21.7 ± 3.1 vs 16.9 ± 4.1 μg/dL; p < 0.001], GH [Median (95% CI): 12.73 (1.1–38.1) vs 4.80 (0.33–27.36) μg/L; p = 0.015], and prolactin [24.3 (10.5–67.45) vs 10.50 (6.21–43.44) ng/mL; p = 0.002]. Cortisol response to CST was similar between ATL and NPAC. During ITT, cortisol, GH, and ACTH mean increase in ATL were 52.2, 265.2, and 18.6% higher than NPAC, respectively. Prolactin response was absent in NPAC, while present in ATL. Conclusions We found sufficient evidence to propose the existence of a diffuse enhancement of the hypothalamic-pituitary activity in athletes, not restricted to any axis, showing an intrinsic and independent process of “hormonal conditioning” in athletes, similar to those observed in the cardiovascular and neuromuscular systems. This novel conditioning process may be the missing link for understanding the improved responses observed in athletes to harmful situations, traumas, infections, inflammations, and psychiatric conditions.