Prognostic Impact of Atrial Fibrillation in Patients with Heavily Calcified Coronary Artery Disease Receiving Rotational Atherectomy.

Background and Objectives: Although both rotational atherectomy (RA) and atrial fibrillation (AF) have a high thrombotic risk, there have been no previous studies on the prognostic impact of AF in patients who undergo percutaneous coronary intervention (PCI) using RA. Thus, the aim of the present study was to determine the prognostic impact of AF in patients undergoing PCI using RA. Materials and Methods: A total of 540 patients who received PCI using RA were enrolled between January 2010 and October 2019. Patients were divided into AF and sinus rhythm groups according to the presence of AF. The primary endpoint was net adverse clinical events (NACEs) defined as a composite outcome of all-cause death, myocardial infarction, target vessel revascularization, cerebrovascular accident, or total bleeding. Results: Although in-hospital adverse events showed no difference between those with AF and those without AF (in-hospital events, 54 (11.0%) vs. 6 (12.2%), p = 0.791), AF was strongly associated with an increased risk of NACE at 3 years (NACE: hazard ratio, 1.880; 95% confidence interval, 1.096-3.227; p = 0.022). Conclusions: AF in patients who underwent PCI using RA was strongly associated with poor clinical outcomes. Thus, more attention should be paid to thrombotic and bleeding risks.

Clinical Outcome of Rotational Atherectomy in Calcified Lesions in Korea-ROCK Registry.

Background and Objectives: Data is still limited regarding clinical outcomes of rotational atherectomy (RA) after percutaneous coronary intervention. We sought to evaluate clinical outcomes of RA. Materials and Methods: This multi-center registry enrolled patients who underwent RA during PCI from nine tertiary centers in Korea between January 2010 and October 2019. The primary endpoint was target-vessel failure (TVF; the composite outcome of cardiac death, target-vessel spontaneous myocardial infarction, or target-vessel revascularization). Results: Of 540 patients (583 lesions), the mean patient age was 71.4 ± 0.4 years, 323 patients (59.8%) were men, and 305 patients (56.5%) had diabetes mellitus. Technical success rate was 96.4%. In-hospital major adverse cerebral and cardiac events occurred in 63 cases (10.8%). At 1.5 years, 72 (16.0%) of TVFs were occurred. We evaluated independent predictors of TVF, which included current smoker (hazard ratio (HR), 1.92; 95% confidence interval (CI), 1.17-3.16; p = 0.01), chronic renal disease (HR, 1.87; 95% CI, 1.14-3.08; p = 0.013), history of cerebrovascular attack (HR, 2.14; 95% CI, 1.24-3.68; p = 0.006), left ventricle ejection fraction (HR, 0.98; 95% CI, 0.97-0.999; p = 0.037), and left main disease (HR, 1.94; 95% CI, 1.11-3.37; p = 0.019). Conclusions: From this registry, we demonstrated acceptable success rates, in-hospital and mid-term clinical outcomes of RA in the DES era.

Star-shaped molecules with polyhedral oligomeric silsesquioxane core and azobenzene dye arms.

We synthesized a series of hybrid nanomaterials combining organic dyes with polyhedral oligomeric silsesquioxanes (POSS) based on three different azobenzenes: monoazobenzene (4-phenylazophenol), bis-azobenzene (Disperse Yellow 7 and Fast Garnet derivative), and push-pull azobenzene (Disperse Red 1) via hydrosilylation coupling. The azo-functionalized POSS compounds possess high thermal stability, and their branched architecture resulted in effective suppression of molecular aggregation and allowed for direct imaging of individual dye-POSS structures with expected molecular dimensions. Stable, uniform, smooth, and ultrathin nanocomposite films with mixed silica-organic composition and relatively low refractive indices can be fabricated from all azo-POSS branched conjugates. Finally, the photoisomerization behavior of POSS-conjugated 4-phenylazophenol was investigated in solution as well as in ultrathin nanocomposite film. We found that conjugation to POSS core did not affect the kinetics of trans-cis photoisomerization and thermal cis-trans relaxation. Furthermore, rapid and reversible photoisomerization was observed in azo-POSS nanocomposite films. We suggest that the highly stable branched azo-POSS conjugates with high dye grafting density described here can be considered for nanometer-sized photoswitches, active layer material with optical-limiting properties, and a medium with photoinduced anisotropy for optical storage.

Star polymer unimicelles on graphene oxide flakes.

We report the interfacial assembly of amphiphilic heteroarm star copolymers (PSnP2VPn and PSn(P2VP-b-PtBA)n (n = 28 arms)) on graphene oxide flakes at the air-water interface. Adsorption, spreading, and ordering of star polymer micelles on the surface of the basal plane and edge of monolayer graphene oxide sheets were investigated on a Langmuir trough. This interface-mediated assembly resulted in micelle-decorated graphene oxide sheets with uniform spacing and organized morphology. We found that the surface activity of solvated graphene oxide sheets enables star polymer surfactants to subsequently adsorb on the presuspended graphene oxide sheets, thereby producing a bilayer complex. The positively charged heterocyclic pyridine-containing star polymers exhibited strong affinity onto the basal plane and edge of graphene oxide, leading to a well-organized and long-range ordered discrete micelle assembly. The preferred binding can be related to the increased conformational entropy due to the reduction of interarm repulsion. The extent of coverage was tuned by controlling assembly parameters such as concentration and solvent polarity. The polymer micelles on the basal plane remained incompressible under lateral compression in contrast to ones on the water surface due to strongly repulsive confined arms on the polar surface of graphene oxide and a preventive barrier in the form of the sheet edges. The densely packed biphasic tile-like morphology was evident, suggesting the high interfacial stability and mechanically stiff nature of graphene oxide sheets decorated with star polymer micelles. This noncovalent assembly represents a facile route for the control and fabrication of graphene oxide-inclusive ultrathin hybrid films applicable for layered nanocomposites.

Comparative Analysis of High-Intensity versus Low-to-Moderate Intensity Statin Therapy in Patients Undergoing Rotational Atherectomy for Calcified Coronary Artery Disease.

(1) Background: Moderate-intensity statin therapy, when compared to high-intensity statin therapy in Asian populations, has shown no significant difference in cardiovascular prognosis in small studies. The aim of this study was to compare the prognosis of patients based on statin intensity following rotational atherectomy (RA) during high-complexity percutaneous coronary intervention (PCI). (2) Methods: The ROCK registry, a multicenter retrospective study, included patients who had undergone rotational atherectomy (RA) during percutaneous coronary intervention (PCI) at nine tertiary medical centers in South Korea between January 2010 and October 2019. The patients were divided into high-intensity statin (H-statin) and moderate/low-intensity statin (M/L-statin) therapy groups. The primary endpoint includes outcomes (cardiac death, target vessel myocardial infarction (MI), and target vessel revascularization (TVR)) within an 18-month follow-up period. (3) Results: In this registry, a total of 540 patients with 583 lesions were included. We excluded 39 lesions from the analysis due to the absence of statin usage. The H-statin group had 394 lesions and the M/L-statin group had 150 lesions. There were no significant differences in baseline characteristics, procedural adverse events without heart failure history, triglycerides, or medications between the two groups. The procedural success rate showed a significant difference between the two groups. Multivariate analysis did not show a significant association between M/L-statin therapy and an increased risk of the primary endpoint. In propensity score matching analysis, no significant difference was observed in the primary endpoint either. (4) Conclusions: In high-complex RA PCI, moderate/low-intensity statin therapy is not inferior to high-intensity statin therapy in Korea.

Impact of Diabetes Duration on Clinical Outcome in Patients Receiving Rotational Atherectomy in Calcified Lesions in Korea-Results from ROCK Registry.

There are limited data regarding the clinical impact of diabetes duration for patients with heavy calcified coronary lesions. We sought to determine the clinical impact of diabetes duration on clinical outcomes in patients with heavily calcified lesions who required rotational atherectomy during percutaneous coronary intervention (PCI). A total of 540 diabetic patients (583 lesions) were enrolled between January 2010 and October 2019. Patients were classified into three subgroups: patients with no diabetes mellitus (non-DM), shorter duration (S-DM), and longer duration (L-DM), of which duration was divided at 10 years. During 18 months of follow-up-duration, diabetes duration was significantly associated with the primary outcome. The incidence rate of target-vessel failure (TVF), the primary outcome, was significantly higher in the L-DM group compared with non-DM or S-DM. Among secondary outcomes, any repeat revascularization (RR) was frequently observed in the L-DM compared with other groups. In multivariate analysis, the risk of TVF and any RR was 1.9 times and 2.4 times higher in L-DM than in non-DM, respectively. This study firstly demonstrated that there is an association between a longer DM duration and poor clinical outcomes in patients with severe calcified CAD after PCI. More careful monitoring for recurrence is needed during follow-up in those patients.

pH-controlled exponential and linear growing modes of layer-by-layer assemblies of star polyelectrolytes.

We report the unique layer-by-layer (LbL) assembly behavior of pH-sensitive star-shaped polyelectrolytes with both linear and exponential growth modes controlled by star architecture and assembly conditions. Cationic poly[2-(dimethylamino)ethyl methacrylate] and anionic poly(acrylic acid) stars were synthesized via "core-first" atom-transfer radical polymerization (ATRP) based on multifunctional initiators, in addition to their linear analogues. We demonstrated the LbL growth behavior as a function of deposition pH (ranging from 5 to 7), number of layers (up to 30 bilayers), and the method of assembly (dip- vs spin-assisted LbL). The spin-assisted LbL assembly makes it possible to render smoother and thinner LbL films with parameters controlled by the shear rate and pH conditions. In contrast, for dip-assisted LbL assembly, the pH-dependent exponential growth was observed for both linear and star polyelectrolytes. In the case of linear/linear pair, the exponential buildup was accompanied with a notable surface segregation which resulted in dramatic surface nonuniformity, "wormlike" heterogeneous morphology, and dramatic surface roughening. In contrast, star/linear and star/star LbL films showed very uniform and smooth surface morphology (roughness below 2.0 nm on the scale of 10 µm × 10 µm) with much larger thickness reaching up to 1.0 µm for 30 bilayers and rich optical interference effects. Star polyelectrolytes with partially screened charges and high mobility caused by compact branched architecture appear to facilitate fast diffusion and exponential buildup of LbL films. We suggest that the fast buildup prevents long-range lateral diffusion of polyelectrolyte star components, hinders large-scale microphase separation, and thus leads to unique thick, smooth, uniform, transparent, and colorful LbL films from star polyelectrolytes in contrast to mostly heterogeneous films from traditional linear counterparts.

Gold nanoparticles grown on star-shaped block copolymer monolayers.

We report on the growth of gold nanoparticles in polystyrene/poly(2-vinyl pyridine) (PS/P2VP) star-shaped block copolymer monolayers. These amphiphilic PS(n)P2VP(n) heteroarm star copolymers differ in molecular weight (149,000 and 529,000 Da) and the number of arms (9 and 28). Langmuir-Blodgett (LB) deposition was utilized to control the spatial arrangement of P2VP arms and their ability to reduce gold nanoparticles. The PS(n)P2VP(n) monolayer acted as a template for gold nanoparticle growth because of the monolayer's high micellar stability at the liquid-solid interface, uniform domain morphology, and ability to adsorb Au ions from the water subphase. UV-vis spectra and AFM and TEM images confirmed the formation of individual gold nanoparticles with an average size of 6 ± 1 nm in the P2VP-rich outer phase. This facile strategy is critical to the formation of ultrathin polymer-gold nanocomposite layers over large surface areas with confined, one-sided positioning of gold nanoparticles in an outer P2VP phase at polymer-silicon interfaces.

Thin film assembly of spider silk-like block copolymers.

We report the self-assembly of monolayers of spider silk-like block copolymers. Langmuir isotherms were obtained for a series of bioengineered variants of the spider silks, and stable monolayers were generated. Langmuir-Blodgett films were prepared by transferring the monolayers onto silica substrates and were subsequently analyzed by atomic force microscopy (AFM). Static contact angle measurements were performed to characterize interactions across the interface (thin film, water, air), and molecular modeling was used to predict 3D conformation of spider silk-like block copolymers. The influence of molecular architecture and volume fraction of the proteins on the self-assembly process was assessed. At high surface pressure, spider silk-like block copolymers with minimal hydrophobic block (f(A) = 12%) formed oblate structures, whereas block copolymer with a 6-fold larger hydrophobic domain (f(A) = 46%) formed prolate structures. The varied morphologies obtained with increased hydrophobicity offer new options for biomaterials for coatings and related options. The design and use of bioengineered protein block copolymers assembled at air-water interfaces provides a promising approach to compare 2D microstructures and molecular architectures of these amphiphiles, leading to more rationale designs for a range of nanoengineered biomaterial needs as well as providing a basis of comparison to more traditional synthetic block copolymer systems.

Gender Differences in the Impact of New-Onset Atrial Fibrillation on Long-Term Risk of Ischemic Stroke after Acute Myocardial Infarction.

BACKGROUND: Atrial fibrillation (AF) has been identified as a major risk factor for mortality after acute coronary syndrome (ACS). However, the long-term risk of ischemic stroke associated with new-onset atrial fibrillation (NOAF) in ACS remains controversial, and its gender-specific association is unknown. METHODS: We analyzed the data of 10,137 ACS survivors included in a multicenter, prospective registry for Korean patients with acute myocardial infarction (AMI) between January 2004 and August 2014. Subjects were categorized into three groups (non-AF vs. NOAF vs. previous AF) based on medical history and electrocardiographic evidence of AF, either at admission or during hospitalization. RESULTS: Among the total study population (72.3% men), 370 patients (3.6%) had NOAF and 130 (1.3%) had previous AF. During a median follow-up of 61 months (interquartile range, 38.8 to 89.3 months), 245 (2.4%) patients (218 (2.3%) non-AF vs. 15 (4.1%) NOAF vs. 12 (9.2%) previous AF, p < 0.001) experienced ischemic stroke. After adjustment for confounding variables, both NOAF (adjusted hazard ratio (HR) 1.87, 95% confidence interval (CI) 1.09-3.24, p = 0.024) and previous AF (adjusted HR 4.00, 95% CI 2.03-7.87, p < 0.001), along with older age, diabetes, current smoker, and previous stroke were independent risk factors of ischemic stroke. In the gender-stratified analysis, men with previous AF but not NOAF had a significantly higher risk of ischemic stroke (adjusted HR 4.14, 95% CI 1.79-9.55, p = 0.001) than those without AF. In women, NOAF (adjusted HR 2.54, 95% CI 1.21-5.35, p = 0.014) as well as previous AF (adjusted HR 3.72, 95% CI 1.16-11.96, p = 0.028) was a strong predictor of ischemic stroke, and the predictive value was comparable to that of previous AF among patients with a CHA2DS2-VASc score ≥ 2. CONCLUSIONS: Both NOAF and previous AF were associated with ischemic stroke after AMI, but the impact of NOAF as a risk factor of ischemic stroke was significant only in women.

Bimetallic nanostructures as active Raman markers: gold-nanoparticle assembly on 1D and 2D silver nanostructure surfaces.

It is demonstrated that bimetallic silver-gold anisotropic nanostructures can be easily assembled from various nanoparticle building blocks with well-defined geometries by means of electrostatic interactions. One-dimensional (1D) silver nanowires, two-dimensional (2D) silver nanoplates, and spherical gold nanoparticles are used as representative building blocks for bottom-up assembly. The gold nanoparticles are electrostatically bound onto the 1D silver nanowires and the 2D silver nanoplates to give bimetallic nanostructures. The unique feature of the resulting nanostructures is the particle-to-particle interaction that subjects absorbed analytes to an enhanced electromagnetic field with strong polarization dependence. The Raman activity of the bimetallic nanostructures is compared with that of the individual nanoparticle blocks by using rhodamine 6G solution as the model analyte. The Raman intensity of the best-performing silver-gold nanostructure is comparable with the dense array of silver nanowires and silver nanoplates that were prepared by means of the Langmuir-Blodgett technique. An optimized design of a single-nanostructure substrate for surface-enhanced Raman spectroscopy (SERS), based on a wet-assembly technique proposed here, can serve as a compact and low-cost alternative to fabricated nanoparticle arrays.

Impact of Cardiorenal Anemia Syndrome on Short- and Long-Term Clinical Outcomes in Patients Hospitalized with Heart Failure.

BACKGROUND: Dysfunctional interplay between the heart and kidneys may lead to the development of anemia. The aim of this study was to evaluate the impact of cardiorenal anemia syndrome (CRAS) on short- and long-term outcomes among patients hospitalized with heart failure (HF). METHODS: We enrolled 303 patients hospitalized with HF. We divided the patients into two groups: a CRAS group (n = 64) and a non-CRAS group (n = 239). We defined CRAS as HF accompanied by (1) an estimated glomerular filtration rate <60 ml/min/1.73 m(2) calculated by the Modification of Diet in Renal Disease at admission and (2) a hemoglobin level <12 g/dl for females and <13 g/dl for males at admission. The primary outcome was a composite of cardiac death, non-fatal myocardial infarction and rehospitalization for HF. RESULTS: During a median follow-up period of 25.6 months (range 0.1-35.3 months), the patients with CRAS had a significantly increased risk for the primary outcome (27.5 vs. 10.7%, p < 0.001) compared with the patients in the non-CRAS group. Using Cox proportional hazard analyses, the hazard ratio (HR) for the presence of CRAS was found to be 1.874 (95% confidence interval [CI] 1.011-3.475, p = 0.046); HRs were also computed for the presence of diabetes mellitus (HR = 2.241, 95% CI 1.221-4.112, p = 0.009), New York Heart Association class III or IV HF (HR = 2.948, 95% CI 1.206-7.205, p = 0.018) and the use of intravenous loop diuretics (HR = 2.286, 95% CI 0.926-5.641, p = 0.073). CONCLUSIONS: Renal dysfunction and anemia are a fatal combination and are associated with poor prognosis in patients with HF.

Novel information on anatomic factors causing grasp reflex in frontal lobe infarction: a case report.

We report a patient with a severe limitation of function in the right hand resulting from grasp reflex following a stroke affecting the left anterior cerebral artery region. We describe, using diffusion tensor tractography (DTT), a disconnection between the bilateral frontal lobes via the corpus callosum. The patient could not control his right hand at all, even though his bilateral corticospinal tracts were intact. We noted that over the infarcted lesion on DTT, the white matter was invisible from the corpus callosum to the prefrontal cortex. These findings reflected a unique pattern of white-matter disconnection between the ipsilateral medial frontal lobe and ipsilateral and contralateral frontal cortex causing hand function deterioration in the form of severe grasp reflex.

Videofluoroscopy-guided balloon dilatation for the opening dysfunction of upper esophageal sphincter by postoperative vagus nerve injury: a report on two cases.

Dysphagia secondary to peripheral cranial nerve injury originates from weak and uncoordinated contraction-relaxation of cricopharyngeal muscle. We report on two patients who suffered vagus nerve injury during surgery and showed sudden dysphagia by opening dysfunction of upper esophageal sphincter (UES). Videofluoroscopy-guided balloon dilatation of UES was performed. We confirmed an early improvement of the opening dysfunctions of UES, although other neurologic symptoms persisted. While we did not have a proper comparison of cases, the videofluoroscopy-guided balloon dilatation of UES is thought to be helpful for the early recovery of dysphagia caused by postoperative vagus nerve injury.

Competitive adsorption of dopamine and rhodamine 6G on the surface of graphene oxide.

Competitive adsorption-desorption behavior of popular fluorescent labeling and bioanalyte molecules, Rhodamine 6G (R6G) and dopamine (DA), on a chemically heterogeneous graphene oxide (GO) surface is discussed in this study. Individually, R6G and DA compounds were found to adsorb rapidly on the surface of graphene oxide as they followed the traditional Langmuir adsorption behavior. FTIR analysis suggested that both R6G and DA molecules predominantly adsorb on the hydrophilic oxidized regions of the GO surface. Thus, when R6G and DA compounds were adsorbed from mixed solution, competitive adsorption was observed around the oxygen-containing groups of GO sheets, which resulted in partial desorption of R6G molecules from the surface of GO into the solution. The desorbed R6G molecules can be monitored by fluorescence change in solution and was dependent on the DA concentration. We suggest that the efficient competitive adsorption of different strongly bound bioanalytes onto GO-dye complex can be used for the development of sensitive and selective colorimetric biosensors.

Measurement of synergy and spasticity during functional movement of the post-stoke hemiplegic upper limb.

The aim of the present study was to measure the muscle-contraction patterns of the hemiplegic upper limb using electromyography (EMG) and to investigate the relationship between muscle co-contraction and functional recovery in stroke patients presenting with synergy and spasticity. The muscle-contraction patterns of the upper limb of 12 chronic stroke patients and 10 normal volunteers were measured, and the co-contraction in the distal and proximal muscles was simultaneously quantified, while the participants performed hand-grasp and shoulder flexion tasks. The spasticity and hemiplegic arm function were evaluated, respectively, on a modified Ashworth scale (MAS) and by means of Fugl-Meyer motor assessment (FMA). The correlation between the MAS and FMA values was analyzed. Increased co-contraction (66-555%) was observed in both the proximal and distal upper limbs, and was positively correlated with spasticity of the elbow flexor (r = 0.944 on shoulder flexion, r = 0.741 on hand grasping, p < 0.01) and negatively correlated with functional recovery of the upper limb (r = -0.670 ∼ -0.884, p < 0.05). Specific movement patterns influenced by synergy and spasticity were confirmed by EMG. These results might prove useful to the formulation of appropriate management plans such as those involving botulinum toxin injection or nerve block.

Nondestructive light-initiated tuning of layer-by-layer microcapsule permeability.

A nondestructive way to achieve remote, reversible, light-controlled tunable permeability of ultrathin shell microcapsules is demonstrated in this study. Microcapsules based on poly{[2-(methacryloyloxy)ethyl] trimethylammonium iodide} (PMETAI) star polyelectrolyte and poly(sodium 4-styrenesulfonate) (PSS) were prepared by a layer-by-layer (LbL) technique. We demonstrated stable microcapsules with controlled permeability with the arm number of a star polymer having significant effect on the assembly structure: the PMETAI star with 18 arms shows a more uniform and compact assembly structure. We observed that in contrast to regular microcapsules from linear polymers, the permeability of the star polymer microcapsules could be dramatically altered by photoinduced transformation of the trivalent hexacyanocobaltate ions into a mixture of mono- and divalent ions by using UV irradiation. The reversible contraction of PMETAI star polyelectrolyte arms and the compaction of star polyelectrolytes in the presence of multivalent counterions are considered to cause the dramatic photoinduced changes in microcapsule properties observed here. Remarkably, unlike the current mostly destructive approaches, the light-induced changes in microcapsule permeability are completely reversible and can be used for light-mediated loading/unloading control of microcapsules.

Inkjet-assisted layer-by-layer printing of encapsulated arrays.

We present the facile fabrication of hydrogen-bonded layer-by-layer (LbL) microscopic dot arrays with encapsulated dye compounds. We demonstrate patterned encapsulation of Rhodamine dye as a model compound within poly(vinylpyrrolidone)/poly(methacrylic acid) (PVPON/PMAA) LbL dots constructed without an intermediate washing step. The inkjet printing technique improves encapsulation efficiency, reduces processing time, facilitates complex patterning, and controls lateral and vertical dimensions with diameters ranging from 130 to 35 µm (mostly controlled by the droplet size and the substrate hydrophobicity) and thickness of several hundred nanometers. The microscopic dots composed of hydrogen-bonded PVPON/PMAA components are also found to be stable in acidic solution after fabrication. This facile, fast, and sophisticated inkjet encapsulation method can be applied to other systems for fast fabrication of large-scale, high-resolution complex arrays of dye-encapsulated LbL dots.

Graphene oxide--polyelectrolyte nanomembranes.

Owing to its remarkable electrical, thermal, and mechanical properties, graphene, an atomic layer of carbon, is considered to be an excellent two-dimensional filler for polymer nanocomposites with outstanding mechanical strength along with the potential for excellent electrical and thermal properties. One of the critical limitations with conventional fillers is that the loading fraction required for achieving significant improvement in mechanical properties is relatively high, frequently reaching 50% for maximum strength. Here, we demonstrate that the mechanical properties of ultrathin laminated nanocomposites can be significantly enhanced by the incorporation of small amounts of a dense monolayer of planar graphene oxide (GO) flakes. Negatively charged functionalized graphene oxide layers were incorporated into polyelectrolyte multilayers (PEMs) fabricated in a layer-by-layer (LbL) assembly via Langmuir-Blodgett (LB) deposition. These LbL-LB graphene oxide nanocomposite films were released as robust freely standing membranes with large lateral dimensions (centimeters) and a thickness of around 50 nm. Micromechanical measurements showed enhancement of the elastic modulus by an order of magnitude, from 1.5 GPa for pure LbL membranes to about 20 GPa for only 8.0 vol % graphene oxide encapsulated LbL membranes. These tough nanocomposite PEMs can be freely suspended over large (few millimeters) apertures and sustain large mechanical deformations.