Kirigami-based metastructures with programmable multistability.

SignificanceDifferent from most existing multistable structures whose multiple stable states are achieved through the combinational effect of bistable units, we invent a generic tristable kirigami cuboid. The three stable states have fundamentally distinct geometric configurations and chirality, and the transformation among them can be realized by tension/compression or clockwise/counterclockwise twist. Tessellating the units in series, a family of multistable metamaterials can be constructed, the mechanical behaviors of which are programmable by the unit geometry, the material of the elastic joints, the number of units, and the loading conditions. As a demonstration of the potential applications, a frequency reconfigurable antenna for 5G triple-band communication is developed based on a tristable unit, and the frequency tunability is verified by experiments.

In vitro quantification of stent-graft behaviour during chimney thoracic endovascular aortic repair.

OBJECTIVE: To quantify dynamic gutter phenomena and endograft deformations during double chimney thoracic endovascular aortic repair (ch-TEVAR) in a physiological model of the thoracic aorta subjected to pulsatile haemodynamic conditions. METHODS: Two in vitro procedures revascularizing the brachiocephalic trunk and left common carotid artery were performed representing both balloon-expandable (BE, Ankura-BeGraft) and self-expandable (SE, Ankura-Viabahn) double ch-TEVAR configurations. Retrospectively gated computed tomography (CT) was used to evaluate endograft behaviour. Device interactions were characterised according to gutter volume, gutter surface deviation, and endograft deformation (D-ratio) at end-diastolic and peak-systolic aortic pressure. RESULTS: Use of BE chimney grafts resulted in three times total gutter volume compared to SE chimney grafts. Gutter volumes were observed to vary dynamically between the end-diastolic and peak-systolic phases of the cardiac cycle, with the most substantial change associated with the BE configuration. Chimney graft deformations were dependent on device type, with SE devices exhibiting up to twice the deformation as BE devices. When adjacent, SE chimney grafts were observed to support each other, and thus tended towards a more consistently circular shape. CONCLUSION: Gutter and chimney graft behaviour were dependent on device type, and exhibited both spatial and temporal variability. This study emphasises notable differences between BE and SE double ch-TEVAR configurations which should be considered when evaluating risk of endoleak. The findings reported here also support the use of gated CT to better identify device-related complications with ch-TEVAR, and can be used in the design of next generation devices.

Prognostic factors for patients with hematologic malignancies admitted to the intensive care unit: is allogeneic transplantation still a risk factor?

The rate of intensive care unit (ICU) mortality in patients with hematologic malignancies is high. The risk factors for this were inconsistent across several previous studies, and there is currently no accepted consensus around risk factors for these patients. We aimed to identify which prognostic factors were associated with ICU mortality in critically ill patients with hematologic malignancies, nearly half of which were allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. In addition, we aimed to compare the characteristics and clinical outcomes of patients with and without allogenic allo-HSCT. In total, 217 patients with hematologic malignancies were enrolled consecutive, 119 (54.8%) of whom underwent HSCT (allo-HSCT: n = 115). All survivors were followed up with until August 1, 2022. The rate of ICU mortality in this cohort was 54.4%: 55.5 and 53.1% for the patients with and without HSCT, respectively (p = 0.724). The probabilities of survival after ICU admission were also comparable between the patients who had allo-HSCT and those who did not. A multivariable analysis revealed that cerebrovascular disease, hyperlactic acidemia on the day of ICU admission, lower platelet count, use of vasoactive drugs, and absence of noninvasive ventilation on the day of ICU admission were independent risk factors for ICU mortality. For patients with three to five of these risk factors, the rate of ICU mortality was as high as 84.6%, which was significantly higher than that of other patients. In this study, the ICU mortality rate in patients with hematologic malignancies was still high, particularly for those with multiple risk factors. However, allo-HSCT was not found to be a risk factor for ICU mortality.

Effectiveness and safety of REBACIN as a non-invasive intervention for persistent high-risk human papillomavirus infection: A real-world prospective multicenter cohort study.

BACKGROUND: We previously reported that REBACIN effectively eliminates persistent high-risk human papillomavirus (hrHPV) infection. Here, we conducted a prospective multicenter cohort study to evaluate the safety and effectiveness of REBACIN, taking into account factors such as specific hrHPV subtype and patient's age. METHODS: According to inclusion/exclusion criteria and participant willingness, 3252 patients were divided into REBACIN group while 249 patients into control group. Patients in REBACIN group received one course treatment of intravaginal administration of REBACIN while no treatment in control group. After drug withdrawal, participants in both groups were followed up. RESULTS: The clearance rate of persistent hrHPV infection in REBACIN group was 60.64%, compared to 20.08% in control group. Specifically, the clearance rates for single-type infection of HPV16 or HPV18 were 70.62% and 69.23%, respectively, which was higher than that of HPV52 (59.04%) or HPV58 (62.64%). In addition, the single, double, and triple/triple+ infections had a clearance rate of 65.70%, 53.31%, and 38.30%, respectively. Moreover, 1635 patients under 40 years old had a clearance rate of 65.14%, while it was 55.08% for 1447 patients over 40 years old. No serious adverse effects were found. CONCLUSION: This study confirmed that REBACIN can effectively and safely eliminate persistent hrHPV infection, which the clearance rate of HPV16/18 is higher than that of HPV52/58, the clearance rate of single-type infection is higher than that of multiple-type infections, and the clearance rate in young patients is higher than that in elder patients, providing a guidance for REBACIN application in clearing hrHPV persistent infection in real-world settings. CLINICAL TRIAL REGISTRATION: Chinese Clinical Trial Registry Registration Number: ChiCTR1800015617 http://www.chictr.org.cn/showproj.aspx?proj=26529 Date of Registration: 2018-04-11.

Earwig fan designing: Biomimetic and evolutionary biology applications.

Technologies to fold structures into compact shapes are required in multiple engineering applications. Earwigs (Dermaptera) fold their fanlike hind wings in a unique, highly sophisticated manner, granting them the most compact wing storage among all insects. The structural and material composition, in-flight reinforcement mechanisms, and bistable property of earwig wings have been previously studied. However, the geometrical rules required to reproduce their complex crease patterns have remained uncertain. Here we show the method to design an earwig-inspired fan by considering the flat foldability in the origami model, as informed by X-ray microcomputed tomography imaging. As our dedicated designing software shows, the earwig fan can be customized into artificial deployable structures of different sizes and configurations for use in architecture, aerospace, mechanical engineering, and daily use items. Moreover, the proposed method is able to reconstruct the wing-folding mechanism of an ancient earwig relative, the 280-million-year-old Protelytron permianum This allows us to propose evolutionary patterns that explain how extant earwigs acquired their wing-folding mechanism and to project hypothetical, extinct transitional forms. Our findings can be used as the basic design guidelines in biomimetic research for harnessing the excellent engineering properties of earwig wings, and demonstrate how a geometrical designing method can reveal morphofunctional evolutionary constraints and predict plausible biological disparity in deep time.

Photonic topological semimetals in bigyrotropic metamaterials.

We investigate the photonic topological phases in bigyrotropic metamaterials characterized by the gyroelectric and gyromagnetic parameters. The underlying medium is considered a photonic analogue of the topological semimetal featured with a pair of Weyl cones separated by a distance in the frequency-wave vector space. As the 'spin'-degenerate condition is satisfied, the photonic system consists of two hybrid modes that are completely decoupled. By introducing the pseudospin states as the basis for the hybrid modes, the photonic system is described by two subsystems in terms of the spin-orbit Hamiltonians with spin 1, which result in nonzero spin Chern numbers that determine the topological properties. Surface modes at the interface between two bigyrotropic metamaterials with opposite sign of the gyrotropic parameters exist in their common gap in the wave vector space, which are analytically formulated by algebraic equations. In particular, two types of surface modes are tangent to or wrapping around the Weyl cones, which form a bent and two twisted surface sheets. At the Weyl frequency, the surface modes contain a typical and two open Fermi arc-like states that concatenate to yield an infinite straight line. Topological features of the bigyrotropic metamaterials are further illustrated with the robust transport of surface modes at an irregular boundary.

Photonic topological insulators in bianisotropic metamaterials.

We analyze the photonic topological phases in bianisotropic metamaterials characterized by a lossless and reciprocal magnetoelectric tensor. The underlying medium is considered a topological insulator that supports a pair of counterpropagating helical edge states. By introducing the pseudospin basis, the photonic system can be described by the spin-orbit Hamiltonians with spin 1, which result in nonzero spin Chern numbers that determine the topological properties. Surface modes at the interface between two bianisotropic media with opposite chirality exist in their common band gap, which are represented by elliptic or hyperbolic equations. In particular, two branches of hyperbolic surfaces are degenerate at the frequency where the chiral nihility occurs, which depict the helical nature of edge states between two distinct topological phases. Topological features of the bianisotropic metamaterials are further illustrated with the robust transport of surface modes at an irregular boundary.

Observation of synergistic antibacterial properties of prodigiosin from Serratia marcescens jx-1 with metal ions in clinical isolates of Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) infections are a major global health problem, and novel and effective antimicrobial drugs are urgently required to combat this life-threatening pathogen. Prodigiosin (PG) is a bacterial secondary metabolite with excellent anticancer and antibacterial properties. However, little is known about the antibacterial function of PG against MRSA. Therefore, the antibacterial efficacy of PG alone and PG in combination with different metal ions against clinic isolates of MRSA and methicillin-sensitive S. aureus (MSSA) strain was evaluated in the present study. The minimum inhibitory concentration of PG against both MRSA and MSSA was 0.25 µg/mL. However, 0.1 µg/mL PG showed a stronger inhibitory effect on MSSA cell growth (47.12%) than on MRSA cell growth (35.87%). Surprisingly, we observed a significant difference (p < 0.01) in membrane integrity between PG-treated MRSA and MSSA using the propidium iodide staining assay. Further, we found that in combination with PG, Zn2+, Al3+, and Cu2+ showed synergistic antibacterial effects against MRSA and MSSA. Our results could increase the current knowledge regarding the efficacy of PG in inhibiting the growth of different types of S. aureus clinical isolates and also offer a novel strategy for developing efficient antibacterial agents.

Cotemplating Assembly and Structural Variation of Three-Dimensional Open-Framework Sulfides.

Open-framework sulfides (H3O)KCu6Ge2S8 (1) and (H3O)RbCu6Ge2S8 (2) were prepared by a cotemplating strategy. This shows that alkali-metal and protonated water cations act as cotemplates to direct the three-dimensional open-framework sulfides. These templates direct two types of one-dimensional channels that arrange parallelly, and different types of templates reside in different types of channels. By introduction of the Cs cation into the synthetic systems of 1 and 2, (H3O)K0.6Cs0.4Cu6Ge2S8 (3) and (H3O)Rb0.75Cs0.25Cu6Ge2S8 (4) were obtained. Compound 3 has a different anionic framework from those of 1 and 2, while 4 is isostructural with 1 and 2.

Autism spectrum disorder is associated with gut microbiota disorder in children.

BACKGROUND: The aim of this study was to evaluate the occurrence and clinical characteristics of autism spectrum disorder (ASD) associated to the stable state of the gut microbiota. METHODS: A total of 9 children with ASD and 6 healthy children used as control were selected and feces samples were collected from all of them. The 16S gene ribosomal RNA sequencing was used to analyze the difference in gut microbiota between healthy control children and ASD patients. RESULTS: The results of 16S sequencing based on operational taxonomic units (OTUs) analysis showed that the ASD group and the healthy control (HC) group had a large difference in the abundance of microbiota at the level of family, genus and species. The abundance of Bacteroidales and Selenomonadales was significantly lower in the ASD group than in the HC group (p = 0.0110 and p = 0.0076, respectively). The abundance of Ruminococcaceae in the ASD group was higher than that in the HC group (p = 0.0285), while the amount of Prevotellaceae was significantly lower in the ASD group than in the HC group (p = 0.0111). The Tax4Fun analysis based on Kyoto Encyclopaedia of Genes and Genomes (KEGG) data indicated differentially expressed functional pathway between the ASD group and healthy control group associated to the nervous system, environmental information processing and cellular processing. CONCLUSIONS: The abundance of gut microbiota in the ASD group is different from that in the healthy control children. These differences affect the biological function of the host. These results suggest that a disorder in the gut microbiota may be associated, at least in part, with ASD in children.

Validation of a Chinese version critical-care pain observation tool in nonintubated and intubated critically ill patients: Two cross-sectional studies.

AIMS AND OBJECTIVES: To validate the Chinese version of the Critical-Care Pain Observation Tool (CPOT) in nonintubated and intubated ICU patients. BACKGROUND: While CPOT was found to have the best psychometric properties among objective pain assessment scales, there is no Chinese version CPOT for nonintubated patients. DESIGN: Cross-sectional design was used in these two observational studies. METHODS: Seventy-six nonintubated patients and 53 intubated patients were assessed to examine internal consistency, criterion-related and discriminative validity of CPOT in the first study. Pain assessment during low pain condition as well as increased pain condition was performed by Numeric Rating Scale (NRS) and the Chinese version COPT. Forty nonintubated patients and 43 intubated patients were assessed to examine inter-rater reliability in the second study. A bedside nurse and a researcher independently executed paired pain assessments with CPOT in the same conditions. The STROBE Statement was followed to guide these studies. RESULTS: The Cronbach's α in nonintubated patients and intubated patients was 0.903-0.930 and 0.868-0.870. The intraclass correlation coefficients (ICCs) in nonintubated patients ranged from 0.959-0.982, and the ICC in intubated patients ranged from 0.947-0.959, confirming the inter-rater reliability. The moderately positive Pearson's correlations between CPOT and NRS scores (r = 0.757-0.838 in nonintubated patients, r = 0.574-0.705 in intubated patients) indicated the criterion-related validity. A significant increase in CPOT scores in the increased pain condition compared with those acquired in the low pain condition verified the discriminative validity. CONCLUSIONS: The Chinese version of CPOT was presented to be valid and reliable for both nonintubated and intubated critically ill adults, which could be applicable for pain assessment in patients in ICU. RELEVANCE TO CLINICAL PRACTICE: This study provides an applicable pain assessment tool for both nonintubated patients and intubated patients in ICU.

Chiral surface waves on hyperbolic-gyromagnetic metamaterials.

The existence of surface waves at the boundary of a hyperbolic-gyromagnetic metamaterial is studied. The surface waves, which are analytically formulated in terms of the eigenfields, appear in the spatial gap between two elliptically polarized bulk modes of the metamaterial. The surface waves are chiral in the sense that they propagate unidirectionally along the edge and reverse the propagation direction upon changing sign of the gyrotropic parameter. The topological feature of the chiral surface waves can be characterized by the Berry phases of the bulk modes, showing the bulk-edge correspondence for the underlying medium. The unidirectionality of the chiral surface waves and their immunity to disorder are further demonstrated by the propagation of electromagnetic waves around sharp corners.

Does training improve diagnostic accuracy and inter-rater agreement in applying the Berlin radiographic definition of acute respiratory distress syndrome? A multicenter prospective study.

BACKGROUND: Poor inter-rater reliability in chest radiograph interpretation has been reported in the context of acute respiratory distress syndrome (ARDS), although not for the Berlin definition of ARDS. We sought to examine the effect of training material on the accuracy and consistency of intensivists' chest radiograph interpretations for ARDS diagnosis. METHODS: We conducted a rater agreement study in which 286 intensivists (residents 41.3%, junior attending physicians 35.3%, and senior attending physician 23.4%) independently reviewed the same 12 chest radiographs developed by the ARDS Definition Task Force ("the panel") before and after training. Radiographic diagnoses by the panel were classified into the consistent (n = 4), equivocal (n = 4), and inconsistent (n = 4) categories and were used as a reference. The 1.5-hour training course attended by all 286 intensivists included introduction of the diagnostic rationale, and a subsequent in-depth discussion to reach consensus for all 12 radiographs. RESULTS: Overall diagnostic accuracy, which was defined as the percentage of chest radiographs that were interpreted correctly, improved but remained poor after training (42.0 ± 14.8% before training vs. 55.3 ± 23.4% after training, p < 0.001). Diagnostic sensitivity and specificity improved after training for all diagnostic categories (p < 0.001), with the exception of specificity for the equivocal category (p = 0.883). Diagnostic accuracy was higher for the consistent category than for the inconsistent and equivocal categories (p < 0.001). Comparisons of pre-training and post-training results revealed that inter-rater agreement was poor and did not improve after training, as assessed by overall agreement (0.450 ± 0.406 vs. 0.461 ± 0.575, p = 0.792), Fleiss's kappa (0.133 ± 0.575 vs. 0.178 ± 0.710, p = 0.405), and intraclass correlation coefficient (ICC; 0.219 vs. 0.276, p = 0.470). CONCLUSIONS: The radiographic diagnostic accuracy and inter-rater agreement were poor when the Berlin radiographic definition was used, and were not significantly improved by the training set of chest radiographs developed by the ARDS Definition Task Force. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov (registration number NCT01704066 ) on 6 October 2012.

Effect of entecavir on CD4+ T-cell subpopulations in patients with chronic hepatitis B.

UNLABELLED:  Background and aims. CD4+ T cells play an important role in response to hepatitis B virus (HBV) infection. We investigated the change in CD4+ T-cell subpopulations and viral load in patients with chronic HBV infection who were treated with entecavir. MATERIAL AND METHODS: Thirty patients with chronic HBV infection were enrolled according to the criteria recommended by the Chinese Society of Infectious Diseases and the Chinese Society of Hepatology. The expressions of signature transcription factors and cytokines of CD4+ T-cell subpopulations were measured in chronic hepatitis B (CHB) patients treated with entecavir treatment. RESULTS: Entecavir treatment significantly attenuated hepatitis B virus DNA load and affected the CD4+ T-cell subsets in CHB patients. A dramatic decrease in the Th17 and Treg cell frequencies and expressions of their related cytokines were found in CHB patients with entecavir treatment. In contrast, entecavir treatment caused a remarkable increase in the Th2 cell frequencies and expressions of their related cytokines. CONCLUSION: Our results suggested that Th17 and Treg cells were the more sensitive subtypes to entecavir- induced inhibition of HBV replication compared to Th1 and Th2 cells in chronic HBV patients.

Osthole confers neuroprotection against cortical stab wound injury and attenuates secondary brain injury.

BACKGROUND: Neuroendoscopy is an innovative technique for neurosurgery that can nonetheless result in traumatic brain injury. The accompanying neuroinflammation may lead to secondary tissue damage, which is the major cause of delayed neuronal death after surgery. The present study investigated the capacity of osthole to prevent secondary brain injury and the underlying mechanism of action in a mouse model of stab wound injury. METHODS: A mouse model of cortical stab wound injury was established by inserting a needle into the cerebral cortex for 20 min to mimic neuroendoscopy. Mice received an intraperitoneal injection of osthole 30 min after surgery and continued for 14 days. Neurological severity was evaluated 12 h and up to 21 days after the trauma. Brains were collected 3-21 days post-injury for histological analysis, immunocytochemistry, quantitative real-time PCR, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and enzyme-linked immunosorbent assays. RESULTS: Neurological function improved in mice treated with osthole and was accompanied by reduced brain water content and accelerated wound closure relative to untreated mice. Osthole treatment reduced the number of macrophages/microglia and peripheral infiltrating of neutrophils and lowered the level of the proinflammatory cytokines interleukin-6 and tumor necrosis factor α in the lesioned cortex. Osthole-treated mice had fewer TUNEL+ apoptotic neurons surrounding the lesion than controls, indicating increased neuronal survival. CONCLUSIONS: Osthole reduced secondary brain damage by suppressing inflammation and apoptosis in a mouse model of stab wound injury. These results suggest a new strategy for promoting neuronal survival and function after neurosurgery to improve long-term patient outcome.

Free radical scavenging activity and neuroprotective potentials of D138, one Cu(II)/Zn(II) Schiff-base complex derived from N,N'-bis(2-hydroxynaphthylmethylidene)-1,3-propanediamine.

There is increasing evidence that free radicals play an important role in neuronal damages induced by diabetes mellitus or cerebral ischemia insults. Antioxidants with free radical scavenging activities have been shown to be beneficial and neuroprotective for these pathological conditions. Here, we report free radical scavenging activity and neuroprotective potential of D138, one copper(II)/zinc(II) Schiff-base complex derived from N,N'-2(2-hydroxynaphthylmethylidene)-1,3-propanediamine. The data from three in vitro assays, 2,2-diphenyl-1-picrylhydrazyl assay, nitro blue tetrazolium assay and hydroxyl radical scavenging assay, indicated that D138 presented a potent free radical scavenging activity. The neuroprotective and antioxidative effects of D138 were further evaluated in vivo using bilateral common carotid artery occlusion (BCCAO) mouse model and streptozotocin (STZ) diabetic mouse model. Our results indicated that treatment of D138 significantly ameliorated the hippocampal neuronal damage and the oxidative stress levels in these animal models. Moreover, D138 also reversed the behavioral deficiencies induced by BCCAO or STZ, as assessed by Y-maze test and fear conditioning test. In conclusion, all these findings support that D138 exerts free radical scavenging and neuroprotective activities and has the potentials to be a potent therapeutic candidate for brain oxidative damage induced by cerebral ischemia or diabetes mellitus.

Characterization of a newly synthesized carbonyl reductase and construction of a biocatalytic process for the synthesis of ethyl (S)-4-chloro-3-hydroxybutanoate with high space-time yield.

A carbonyl reductase (SCR2) gene was synthesized and expressed in Escherichia coli after codon optimization to investigate its biochemical properties and application in biosynthesis of ethyl (S)-4-chloro-3-hydroxybutanoate ((S)-CHBE), which is an important chiral synthon for the side chain of cholesterol-lowering drug. The recombinant SCR2 was purified and characterized using ethyl 4-chloro-3-oxobutanoate (COBE) as substrate. The specific activity of purified enzyme was 11.9 U mg(-1). The optimum temperature and pH for enzyme activity were 45 °C and pH 6.0, respectively. The half-lives of recombinant SCR2 were 16.5, 7.7, 2.2, 0.41, and 0.05 h at 30 °C, 35 °C, 40 °C, 45 °C, and 50 °C, respectively, and it was highly stable in acidic environment. This SCR2 displayed a relatively narrow substrate specificity. The apparent K m and V max values of purified enzyme for COBE are 6.4 mM and 63.3 µmol min(-1) mg(-1), respectively. The biocatalytic process for the synthesis of (S)-CHBE was constructed by this SCR2 in an aqueous-organic solvent system with a substrate fed-batch strategy. At the final COBE concentration of 1 M, (S)-CHBE with yield of 95.3% and e.e. of 99% was obtained after 6-h reaction. In this process, the space-time yield per gram of biomass (dry cell weight, DCW) and turnover number of NADP(+) to (S)-CHBE were 26.5 mmol L(-1) h(-1) g(-1) DCW and 40,000 mol/mol, respectively, which were the highest values as compared with other works.

Chemical and enzymatic approaches to the synthesis of optically pure ethyl (R)-4-cyano-3-hydroxybutanoate.

Ethyl (R)-4-cyano-3-hydroxybutanoate (HN) is an important chiral synthon for side chain of the cholesterol-lowering drug atorvastatin (Lipitor), which is the hydroxymethylglutaryl CoA reductase inhibitor. HN is also used as a synthon in the production of L-carnitine and (R)-4-amino-3-hydroxybutanoic acid. It is necessary to have a clear understanding of the synthesis process of HN for its extensive use. This review gives an overview of different synthetic strategies of optically active HN, including chemical and enzymatic approaches. The emphasis is focused mainly on the synthetic routes using biocatalysts, such as halohydrin dehalogenase, nitrilase, carbonyl reductase, and lipase.

Variable Stiffness Fibers Enabled Universal and Programmable Re-Foldability Strategy for Modular Soft Robotics.

Origami is a rich source of inspiration for creating soft actuators with complex deformations. However, implementing the re-foldability of origami on soft actuators remains a significant challenge. Herein, a universal and programmable re-foldability strategy is reported to integrate multiple origami patterns into a single soft origami actuator, thereby enabling multimode morphing capability. This strategy can selectively activate and deactivate origami creases through variable stiffness fibers. The utilization of these fibers enables the programmability of crease pattern quantity and types within a single actuator, which expands the morphing modes and deformation ranges without increasing their physical size and chamber number. The universality of this approach is demonstrated by developing a series of re-foldable soft origami actuators. Moreover, these soft origami actuators are utilized to construct a bidirectional crawling robot and a multimode soft gripper capable of adapting to object size, grasping orientation, and placing orientation. This work represents a significant step forward in the design of multifunctional soft actuators and holds great potential for the advancement of agile and versatile soft robots.