Durable Polymer Research Articles

Tissue responses to everolimus-eluting stents implanted in severely calcified lesions following atherectomy

Histopathological examination has revealed that stents on severely calcified plaques were associated with delayed vascular healing. Although atherectomy devices can increase the number of malapposed struts, tissue responses to implanted drug eluting stents in atherectomy patients remain largely unknown. This retrospective observational study included 30 patients who underwent atherectomy and everolimus-eluting stent (EES) deployment for severely calcified coronary lesions (biodegradable polymer EES (BP-EES), n = 15; durable polymer EES (DP-EES), n = 15). Optical coherence tomography was carried out at baseline and follow-up, and struts with acute stent malapposition (ASM) were categorized as struts on modified calcium (mod-Ca), non-modified calcium (non-mod-Ca), or non-calcium (non-Ca). Adequate vascular healing, defined as ASM resolution with neointimal coverage, was compared between the BP-EES and DP-EES groups. Multivariate linear regression analysis using a generalized estimated equation revealed that BP-EES use was associated with significantly better adequate vascular healing compared with DP-EES (odds ratio [OR]: 3.691, 95% confidence interval [CI] 1.175–11.592, P = 0.025). adequate vascular healing was associated with the underlying plaque morphology (mod-Ca vs non-mod-Ca: OR 2.833, 95% CI 1.491–5.384, P = 0.001; non-Ca vs non-mod-Ca: OR 1.248, 95% CI 0.440–3.543, P = 0.677). This study demonstrates that drug-eluting stent selection and calcium modification are possible factors affecting vascular healing of malapposed struts in severely calcified lesions.Graphical

Randomized clinical trial of abluminus DES+ sirolimus-eluting stent versus everolimus-eluting DES for percutaneous coronary intervention in patients with diabetes mellitus: An optical coherence tomography study.

Diabetic patients are at higher risk of recurrent adverse events following percutaneous coronary intervention (PCI) than the nondiabetics. Despite the introduction of new generation drug-eluting stents, their efficacy in the diabetics is still limited. To evaluate the efficacy of the Abluminus DES+ biodegradable polymer sirolimus-eluting stent in reducing neointimal hyperplasia in diabetic patients, compared to a durable polymer everolimus-eluting stent (DP-EES). A total of 131 patients with diabetes and coronary artery disease were enrolled in six Italian centers and randomized in a 2:1 fashion to PCI with Abluminus DES+ or DP-EES: 85 were assigned to Abluminus DES+ and 46 to DP-EES. The primary endpoint was optimal coherence tomography (OCT)-derived neointimal volume at 9-12 months. Secondary endpoints included OCT-derived neointimal area, neointimal volume obstruction and adverse clinical events. The primary endpoint, neointimal volume, did not differ between Abluminus DES+ and DP-EES (29.11 ± 18.90 mm3 vs. 25.48 ± 17.04 mm3 , p = 0.40) at 9-12-month follow-up. This finding remained consistent after weighing for the sum of stents lengths (1.14 ± 0.68 mm3 vs. 0.99 ± 0.74 mm3 for Abluminus DES+ and DP-EES, respectively, p = 0.38). Similarly, other OCT-derived and clinical secondary endpoints did not significantly differ between the two groups. Rate of target lesion failure was high in both groups (21.2% for Abluminus DES+ and 19.6% for DP-EES). This preliminary study failed to demonstrate the superiority of the Abluminus DES+ over the DP-EES in diabetic patients in terms of neointimal proliferation.

Durable and impact-resistant thermoset polymers for the extreme environment of low Earth orbit

Polymers degrade rapidly in low-Earth orbit (LEO) due to extreme thermal cycling, solar radiation, micrometeoroid and orbital micro-debris impact, and the synergistic erosive effects of atomic oxygen (AO) with UV radiation. In this work, we investigate the synergistic effect of (AO+UV)-induced erosion and high-velocity impact damage on a tough thermoset, polydicyclopentadiene (pDCPD), via erosion yield measurements after a long-term LEO exposure in the ram orientation aboard the International Space Station (ISS) followed by ground-based hypervelocity impact tests. The incorporation of SiO2 nanoparticles reduces the AO-erosion rate by an order of magnitude, while also mitigating the associated degradation of surface mechanical properties. Moreover, the resistance of pDCPD to AO-erosion increases with crosslink density. Hypervelocity impact tests using sub-millimeter laser-driven flyer plates launched at 4.5 km s−1 reveal that pDCPD has higher impact resistance than epoxies with comparable erosion resistance. Interestingly, both epoxy and pDCPD exhibit a statistically insignificant change in impact resistance following surface AO-erosion during direct exposure to space vehicle ram conditions (7.8 km s−1) in LEO.

Biodegradable or durable polymer drug-eluting stents in patients with coronary artery disease: ten-year outcomes of the randomised NEXT Trial.

There are no randomised trials reporting clinical outcomes of biodegradable polymer biolimus-eluting stents (BP-BES) and durable polymer everolimus-eluting stents (DP-EES) at 10years. We aimed to compare the 10-year clinical outcomes between BP-BES and DP-EES. The randomised NOBORI Biolimus-Eluting Versus XIENCE/PROMUS Everolimus-eluting Stent Trial (NEXT) was originally designed to evaluate the non-inferiority of BP-BES relative to DP-EES with the primary efficacy endpoint of target lesion revascularisation (TLR) at 1year and the primary safety endpoint of death or myocardial infarction (MI) at 3years. In this extended follow-up study, clinical outcomes were compared from 1year after stent implantation up to 10years between patients with BP-BES and DP-EES. From May to October 2011, NEXT enrolled atotal of 3,241patients from 98 centres in Japan. The current study population consisted of 2,417patients (1,204patients with BP-BES and 1,213 with DP-EES) from 66 centres that agreed to participate in the extended study. Complete 10-year follow-up was achieved in 87.5% of patients. The cumulative 10-year incidence of death or MI was 34.0% in the BP-BES group and 33.1% in the DP-EES group (hazard ratio [HR] 1.04, 95% confidence interval [CI]: 0.90-1.20; p=0.58). TLR occurred in 15.9% of patients in the BP-BES group and in 14.1% of the DP-EES group (HR 1.12, 95% CI: 0.90-1.40; p=0.32). In alandmark analysis at 1year, the cumulative incidences of death or MI and TLR were not significantly different between the 2 groups. The safety and efficacy outcomes for BP-BES were not significantly different from those for DP-EES at 1year and up to 10years after stent implantation.

A Randomized Controlled Trial Comparing BioMime Sirolimus-Eluting Stent With Everolimus-Eluting Stent: Two-Year Outcomes of the meriT-V Trial.

Drug-eluting stents (DESs) based on biodegradable polymers (BPs) have been introduced to reduce the risk for late and very late stent thrombosis (ST), which were frequently observed with earlier generations of DES designs based on durable polymers (DPs); however, randomized controlled trials on these DES designs are scarce. The meriT-V trial is a randomized, active-controlled, non-inferiority trial with a prospective, multicenter design that evaluated the 2-year efficacy of a novel third-generation, ultra-thin strut, BP-based BioMime sirolimus-eluting stent (SES) versus the DP-based XIENCE everolimus-eluting stent (EES) for the treatment of de novo lesions. The meriT-V is a randomized trial that enrolled 256 patients at 15 centers across Europe and Brazil. Here, we report the outcomes of the extended follow-up period of 2 years. The randomization of enrolled patients was in a 2:1 ratio; the enrolled patients received either the BioMime SES (n = 170) or the XIENCE EES (n = 86). The three-point major adverse cardiac event (MACE), defined as a composite of cardiac death, myocardial infarction (MI), or ischemia-driven target vessel revascularization (ID-TVR), was considered as the composite safety and efficacy endpoint. Ischemia-driven target lesion revascularization (ID-TLR) was evaluated as well as the frequency of definite/probable ST, based on the first Academic Research Consortium definitions. The trial had a 2-year follow-up completion rate of 98.44% (n = 252/256 patients), and the clinical outcomes assessment showed a nonsignificant difference in the cumulative rate of three-point MACE between both arms (BioMime vs. XIENCE: 7.74% vs. 9.52%, P = 0.62). Even the MI incidences in the BioMime arm were insignificantly lower than those of the XIENCE arm (1.79% vs. 5.95%, P = 0.17). Late ST was observed in 1.19% cases of the XIENCE arm, while there were no such cases in the BioMime arm (P = 0.16). The objective comparisons between the novel BP-based BioMime SES and the well-established DP-based XIENCE EES in this randomized controlled trial show acceptable outcomes of both the devices in the cardiac deaths, MI, ID-TVR, and ST. Moreover, since there were no incidences of cardiac death in the entire study sample over the course of 2 years, we contend that the findings of the study are highly significant for both these DES designs. In this preliminary comparative trial, the device safety of BioMime SES can be affirmed to be acceptable, considering the lower three-point MACE rate and absence of late ST in the BioMime arm over the 2-year period.

Outcome of percutaneous coronary intervention using ultrathin-strut biodegradable polymer sirolimus-eluting versus thin-strut durable polymer zotarolimus-eluting stents in patients with comorbid peripheral arterial disease: a post-hoc analysis from two randomized trials.

In patients with peripheral arterial disease (PADs), who underwent percutaneous coronary intervention (PCI), little is known about the potential impact of using different new-generation drug-eluting stents (DES) on outcome. In PCI all-comers, the results of most between-stent comparisons-stratified by strut thickness-suggested some advantage of coronary stents with ultrathin-struts. The current post-hoc analysis aimed to assess outcomes of PCI with ultrathin-strut biodegradable polymer sirolimus-eluting stents (BP-SES) vs. thin-strut durable polymer zotarolimus-eluting stents (DP-ZES) in patients with PADs. We pooled 3-year patient-level data from two large-scale randomized all-comer trials to compare Orsiro ultrathin-strut BP-SES vs. Resolute-type thin-strut DP-ZES in trial participants with concomitant PADs. BIO-RESORT (December 2012 to August 2015) and BIONYX (October 2015 to December 2016) included all-comer patients who were aged 18 years or older, capable of providing informed consent, and required a PCI. The trials had web-based randomization, with block sizes of 4 and 8, performed in a 1:1:1 or 1:1 fashion. Assessors, research staff, and patients were blinded to the type of stent used. We assessed the composite main clinical endpoint target vessel failure [TVF: cardiac death, target vessel related myocardial infarction (MI), or clinically indicated target vessel revascularization (TVR)], its components, and stent thrombosis. Of 4,830 trial participants, 360 had PADs: 177 (49.2%) were treated with BP-SES and 183 (50.8%) with DP-ZES. Baseline characteristics were similar. For BP-SES, the 3-year TVF rate was 11.0% and for DP-ZES 17.9% [hazard ratio (HR): 0.59, 95% CI: 0.33-1.04; P=0.07]. For BP-SES, the TVR rate was lower than for DP-ZES (4.1% vs. 11.0%; HR: 0.36, 95% CI: 0.15-0.86; P=0.016), but this did not translate into between-group differences in cardiac death or MI. In small vessels (<2.75 mm), the TVR rate was also lower in BP-SES (5.6% vs. 13.9%; HR: 0.32, 95% CI: 0.11-0.91; P=0.024). Definite-or-probable stent thrombosis rates were 1.2% and 2.3% (P=0.43). In PCI patients with PADs, the 3-year TVF incidence was numerically lower in the ultrathin-strut BP-SES vs. the thin-strut DP-ZES group. Furthermore, TVR risk was significantly lower in ultrathin-strut BP-SES, mainly driven by a lower TVR rate in small vessels. BIO-RESORT trial: clinicaltrials.gov (NCT01674803); BIONYX trial: clinicaltrials.gov (NCT02508714).

Percutaneous coronary intervention with ridaforolimus-eluting stents in long lesions: the BIONICS 38 mm prospective trial.

The ridaforolimus-eluting stent (RES) system is a novel cobalt alloy-based coronary stent with a durable elastomeric polymer eluting ridaforolimus. The aim of this trial was to assess the performance of a 38 mm RES in long coronary lesions. A prospective, multicenter, single-arm, open-label clinical trial. Clinical follow-up was performed at 30 days, 6 months, and 1 year after the procedure. Target lesions were located in native coronary arteries or bypass graft conduits, with visually estimated diameters of ≥2.75 mm to ≤4.25 mm. The primary endpoint was combined efficacy (final in-stent residual diameter stenosis <30%) without 30-day major adverse cardiovascular events (MACE) (composite of cardiac death, any myocardial infarction), or ischemia-driven target lesion revascularization. A total of 50 patients were enrolled in the study. Fourteen (28%) had acute coronary syndromes; 17 (34%) had diabetes. The mean lesion length was 32.4 mm ± 8.3, reference vessel diameter 2.88 mm ± 0.45, minimal lumen diameter 0.80 mm ± 0.41, and percent diameter stenosis 72.6% ± 13.2. The primary endpoint was achieved in 88% (44/50) of the patients (95% confidence interval: 75.7-95.5%). Thirty-day and 1-year MACE rates were 6% and 8%, respectively. Target lesion failure after 1 year occurred in three patients (6%). Forty-seven lesions (94%) were treated successfully, with final in-stent diameter stenosis of < 30% [95% confidence interval: (84-99%). Percutaneous coronary intervention (PCI) of long lesions with a 38 mm RES achieved satisfactory results, and support the safety and efficacy of PCI with RES in patients with long lesions. (ClinicalTrials.gov NCT03702608).

Engineered and Durable Antimicrobial Polymer via Controllable Immobilization of Ionic Liquids onto the Poly(lactic acid) Chains.

Nowadays, the development of effective modification methods for PLA has gained significant interest because of the wide application of antimicrobial PLA materials in the medical progress. Herein, the ionic liquid (IL) 1-vinyl-3-butylimidazolium bis(trifluoromethylsulfonyl)imide, has been grafted onto the PLA chains successfully in the PLA/IL blending films via electron beam (EB) radiation for the miscibility between PLA and IL. It was found that the existence of IL in the PLA matrix can significantly improve the chemical stability under EB radiation. The Mn of PLA-g-IL copolymer did not change obviously but was just decreased from 6.80 × 104 g/mol to 5.20 × 104 g/mol after radiation with 10 kGy. The obtained PLA-g-IL copolymers showed excellent filament forming property during electrospinning process. The spindle structure on the nanofibers can be completely eliminated after feeding only 0.5 wt % ILs for the improvement of ionic conductivity. Specially, the prepared PLA-g-IL nonwovens exhibited outstanding and durable antimicrobial activity for the enrichment of immobilized ILs on the nanofiber surface. This work provides a feasible strategy to realize the modification of functional ILs onto PLA chains with low EB radiation doses, which may have huge potential application in the medical and packaging industry.

Investigation on Physico Chemical and X-ray Shielding Performance of Zinc Doped Nano-WO3 Epoxy Composite for Light Weight Lead Free Aprons.

This report addresses a way to reduce the usage of highly toxic lead in diagnostic X-ray shielding by developing a cost-effective, eco-friendly nano-tungsten trioxide (WO3) epoxy composite for low-weight aprons. Zinc (Zn)-doped WO3 nanoparticles of 20 to 400 nm were synthesized by an inexpensive and scalable chemical acid-precipitation method. The prepared nanoparticles were subjected to X-ray diffraction, Raman spectroscopy, UV-visible spectroscopy, photoluminescence, high-resolution-transmission electron microscope, scanning electron microscope, and the results showed that doping plays a critical role in influencing the physico-chemical properties. The prepared nanoparticles were used as shielding material in this study, which were dispersed in a non-water soluble durable epoxy resin polymer matrix and the dispersed materials were coated over a rexine cloth using the drop-casting method. The X-ray shielding performance was evaluated by estimating the linear attenuation coefficient (μ), mass attenuation coefficient (μm), half value layer (HVL), and X-ray percentage of attenuation. Overall, an improvement in X-ray attenuation in the range of 40-100 kVp was observed for the undoped WO3 nanoparticles and Zn-doped WO3 nanoparticles, which was nearly equal to lead oxide-based aprons (reference material). At 40 kVp, the percentage of attenuation of 2% Zn doped WO3 was 97% which was better than that of other prepared aprons. This study proves that 2% Zn doped WO3 epoxy composite yields a better particle size distribution, μm, and lower HVL value and hence it can be a convenient lead free X-ray shielding apron.

Ultrathin-strut vs thin-strut drug-eluting stents for multi and single-stent lesions: A lesion-level subgroup analysis of 2 randomized trials

Whether ultrathin-strut stents are particularly beneficial for lesions requiring implantation of more than 1 stent is unknown. In a post-hoc lesion-level analysis of 2 randomized trials comparing ultrathin-strut biodegradable polymer Sirolimus-eluting stents (BP-SES) vs thin-strut durable polymer Everolimus-eluting stents (DP-EES), lesions were stratified into multistent lesions (MSL) vs single-stent lesions (SSL). The primary endpoint was target lesion failure (TLF), a composite of lesion-related unclear/cardiac death, myocardial infarction (MI), or revascularization, at 24 months. Among 5328 lesions in 3397 patients, 1492 (28%) were MSL (722 with BP-SES, 770 with DP-EES). At 2 years, TLF occurred in 63 lesions (8.9%) treated with BP-SES and 60 lesions (7.9%) treated with DP-EES in the MSL-group (subdistibution hazard ratio [SHR], 1.13; 95% CI, 0.77-1.64; P=.53), and in 121 (6.4%) and 136 (7.4%) lesions treated with BP-SES and DP-EES respectively (SHR, 0.86; 95% CI, 0.62-1.18; P=.35) in the SSL-group (P for interaction=.241). While the rates of lesion-related MI or revascularization were significantly lower in SSL treated with BP-SES as compared to DP-EES (3.5% vs 5.2%; SHR, 0.67; 95% CI 0.46-0.97; P=.036), no significant difference was observed in MSL (7.1% vs 5.4%; SHR, 1.31; 95% CI 0.85-2.03; P=.216) with significant interaction between groups (P for interaction=.014). Rates of TLF are similar between ultrathin-strut BP-SES and thin-strut DP-EES in MSL and SSL. The use of ultrathin-strut BP-SES vs thin-strut DP-EES did not prove to be particularly beneficial for the treatment of multistent lesions. Post-hoc analysis from the BIOSCIENCE (NCT01443104) and BIOSTEMI (NCT02579031) trials.

The Supreme Biodegradable Polymer DES in Acute and Chronic Coronary Syndromes: A PIONEER III Substudy.

The PIONEER III trial demonstrated noninferiority of 12-month target lesion failure (TLF) with the Supreme DES (Sinomed), a thin-strut cobalt-chromium, biodegradable polymer, sirolimus-eluting stent, compared with a durable polymer, everolimus-eluting (XIENCE/PROMUS) stent (DP-EES). The relative safety and effectiveness of the Supreme DES in patients with acute coronary syndromes (ACS) and those with chronic coronary syndromes (CCS) is not known. PIONEER III was a prospective, multicenter, international, 2:1 randomized trial stratified by clinical presentation. The primary end point was TLF at 12 months (a composite of cardiac death, target vessel myocardial infarction, or ischemia-driven target lesion revascularization). A total of 1628 patients were enrolled, including 41% of patients with ACS (unstable angina and non-ST-elevation myocardial infarction) randomized to Supreme DES (n = 441) versus DP-EES (n = 232) and 59% of patients with CCS randomized to Supreme DES (n = 645) versus DP-EES (n = 310). Patients with ACS were younger, fewer presented with less diabetes, hypertension, and previous revascularization, but more were current smokers. The primary end point of TLF (6.4% vs 4.4%; P = .1), major adverse cardiac events (8.5% vs 6.5%; P = .16), and stent thrombosis (0.4% vs 0.9%; P = .25) at 12 months were similar in the ACS and CCS groups. There was no difference in TLF at 12 months between Supreme DES and DP-EES among patients with ACS (6.6% vs 6.0%; P = .89) and those with CCS (4.5% vs 4.3%; P = .83); interaction P = .51 for TLF by clinical presentation. Compared with the DP-EES, the Supreme DES seemed safe and effective with a similar TLF at 12 months in both patients with ACS and those with CCS.

ETFE and its Role in the Fabrication of Lightweight c-Si Solar Modules

Glass-free, lightweight, photovoltaic modules have the potential to enable new uses of solar in building integrated and vehicle integrated applications. Glass-free modules have the advantages of reduced weight, lower-cost mounting solutions, and reduced transportation costs. Ethylene tetrafluoroethylene (ETFE) is usually considered a suitable candidate to replace glass as the front cover sheet material in module fabrication. In this article, we report on its optical, chemical, self-cleaning, and morphological properties. Durability is a key issue, especially for building-integrated applications since harsh conditions are prevalent outdoors. We report on the effect of sequences of environmental stress tests (UV exposure, and Damp Heat). The module cover material is also subject to regular cleaning, which can cause surface damage. We report on the use of linear abrasion testing to assess the abrasion resistance of ETFE to a variety of abrasive materials. The results provide useful data on the advantages and disadvantages of replacing glass with a durable polymer for front sheets in solar modules.

Toward Protein-Repellent Surface Coatings from Catechol-Containing Cationic Poly(2-ethyl-2-oxazoline)

Inspired by mussel proteins that enable surface binding in harsh marine environments, we envisioned a platform of protein-repellent macromolecules based on poly(2-ethyl-2-oxazoline) carrying catechol and cationic functional groups. To facilitate surface attachment, catechol units were installed by copolymerizing a functional comonomer, i.e., 2-(3,4-dimethoxyphenyl)-2-oxazoline, in a gradient fashion. Cationic units were introduced by partial acidic hydrolysis. The surface affinity of these polymers was probed using a quartz crystal microbalance with dissipation monitoring (QCM-D), and it was found that polymers with catechol units had a strong tendency to form surface-bound layers on different substrates, i.e., gold, iron, borosilicate, and polystyrene. While the neutral catechol-containing polymers showed strong, but uncontrolled binding, the ones with additional cationic units were able to form defined and durable polymer films. These coatings were able to prevent the attachment of different model proteins, i.e., bovine serum albumin (BSA), fibrinogen (FI), or lysozyme (LYZ). The herein-introduced platform offers straightforward access to nonfouling surface coatings using a biomimetic approach.

Five-year outcomes of biodegradable versus second-generation durable polymer drug-eluting stents used in complex percutaneous coronary intervention.

There are few data comparing clinical outcomes of complex percutaneous coronary intervention (CPCI) when using biodegradable polymer drug-eluting stents (BP-DES) or second-generation durable polymer drug-eluting stents (DP-DES). The purpose of this study was to investigate the safety and efficacy of BP-DES and compare that with DP-DES in patients with and without CPCI during a 5-year follow-up. Patients who exclusively underwent BP-DES or DP-DES implantation in 2013 at Fuwai Hospital were consecutively enrolled and stratified into two categories based on CPCI presence or absence. CPCI included at least one of the following features: unprotected left main lesion, ≥2 lesions treated, ≥2 stents implanted, total stent length >40 mm, moderate-to-severe calcified lesion, chronic total occlusion, or bifurcated target lesion. The primary endpoint was major adverse cardiac events (MACE) including all-cause death, recurrent myocardial infarction, and total coronary revascularization (target lesion revascularization, target vessel revascularization [TVR], and non-TVR) during the 5-year follow-up. The secondary endpoint was total coronary revascularization. Among the 7712 patients included, 4882 (63.3%) underwent CPCI. Compared with non-CPCI patients, CPCI patients had higher 2- and 5-year incidences of MACE and total coronary revascularization. Following multivariable adjustment including stent type, CPCI was an independent predictor of MACE (adjusted hazard ratio [aHR]: 1.151; 95% confidence interval [CI]: 1.017-1.303, P = 0.026) and total coronary revascularization (aHR: 1.199; 95% CI: 1.037-1.388, P = 0.014) at 5 years. The results were consistent at the 2-year endpoints. In patients with CPCI, BP-DES use was associated with significantly higher MACE rates at 5 years (aHR: 1.256; 95% CI: 1.078-1.462, P = 0.003) and total coronary revascularization (aHR: 1.257; 95% CI: 1.052-1.502, P = 0.012) compared with that of DP-DES, but there was a similar risk at 2 years. However, BP-DES had comparable safety and efficacy profiles including MACE and total coronary revascularization compared with DP-DES in patients with non-CPCI at 2 and 5 years. Patients underwent CPCI remained at a higher risk of mid- to long-term adverse events regardless of the stent type. The effect of BP-DES compared with DP-DES on outcomes was similar in CPCI and non-CPCI patients at 2 years but had inconsistent effects at the 5-year clinical endpoints.

Mechanistically Novel Frontal‐Inspired In Situ Photopolymerization: An Efficient Electrode|Electrolyte Interface Engineering Method for High Energy Lithium Metal Polymer Batteries

The solvent‐free in situ polymerization technique has the potential to tailor‐make conformal interfaces that are essential for developing durable and safe lithium metal polymer batteries (LMPBs). Hence, much attention has been given to the eco‐friendly and rapid ultraviolet (UV)‐induced in situ photopolymerization process to prepare solid‐state polymer electrolytes. In this respect, an innovative method is proposed here to overcome the challenges of UV‐induced photopolymerization (UV‐curing) in the zones where UV‐light cannot penetrate, especially in LMPBs where thick electrodes are used. The proposed frontal‐inspired photopolymerization (FIPP) process is a diverged frontal‐based technique that uses two classes (dual) of initiators to improve the slow reaction kinetics of allyl‐based monomers/oligomers by at least 50% compared with the conventional UV‐curing process. The possible reaction mechanism occurring in FIPP is demonstrated using density functional theory calculations and spectroscopic investigations. Indeed, the initiation mechanism identified for the FIPP relies on a photochemical pathway rather than an exothermic propagating front forms during the UV‐irradiation step as the case with the classical frontal photopolymerization technique. Besides, the FIPP‐based in situ cell fabrication using dual initiators is advantageous over both the sandwich cell assembly and conventional in situ photopolymerization in overcoming the limitations of mass transport and active material utilization in high energy and high power LMPBs that use thick electrodes. Furthermore, the LMPB cells fabricated using the in situ‐FIPP process with high mass loading LiFePO4 electrodes (5.2 mg cm‐2) demonstrate higher rate capability, and a 50% increase in specific capacity against a sandwich cell encouraging the use of this innovative process in large‐scale solid‐state battery production.

Complex primary percutaneous coronary intervention with ultrathin-strut biodegradable versus thin-strut durable polymer drug-eluting stents in patients with ST-segment elevation myocardial infarction: A subgroup analysis from the BIOSTEMI randomized trial.

Ultrathin-strut biodegradable polymer sirolimus-eluting stents (BP-SES) are superior to thin-strut durable polymer everolimus-eluting stents (DP-EES) with respect to target lesion failure (TLF) at 2 years among patients with ST-segment elevation myocardial infarction (STEMI). We sought to determine the impact of primary percutaneous coronary intervention (pPCI) complexity on long-term clinical outcomes with BP-SES versus DP-EES in STEMI patients. We performed a post hoc subgroup analysis from the BIOSTEMI (NCT02579031) randomized trial, which included individual data from 407 STEMI patients enrolled in the BIOSCIENCE trial (NCT01443104). STEMI patients were randomly assigned to treatment with ultrathin-strut BP-SES or thin-strut DP-EES, and further categorized into those undergoing complex versus noncomplex pPCI. Complex pPCI was defined by the presence of ≥1 of the following criteria: 3 vessel treatment, ≥3 stents implanted, ≥3 lesions treated, bifurcation lesion with ≥2 stents implanted, total stent length ≥60 mm, and/or chronic total occlusion treatment. The primary endpoint was TLF, a composite of cardiac death, target-vessel myocardial reinfarction, or clinically indicated target lesion revascularization, within 2 years. Among a total of 1707 STEMI patients, 421 (24.7%) underwent complex pPCI. Baseline characteristics were similar between groups. At 2 years, TLF occurred in 14 patients (7.1%) treated with BP-SES and 25 patients (11.6%) treated with DP-EES (hazard ratio [HR]: 0.62; 95% confidence interval [CI]: 0.32-1.19; p = 0.15) in the complex pPCI group, and in 28 patients (4.4%) treated with BP-SES and 49 patients (8.2%) treated with DP-EES(HR: 0.54; 95% CI:0.34-0.86; p = 0.008; p for interaction = 0.74) in the noncomplex pPCI group. Individual TLF components and stent thrombosis rates did not significantly differ between groups. In a post hoc subgroup analysis from the BIOSTEMI randomized trial, ultrathin-strut BP-SESwere superior to thin-strut DP-EES with respect to TLF at 2 years among STEMI patients undergoing both complex and noncomplex pPCI.

Long-term atomic oxygen resistant polyimide films containing carborane nanocage structure in the main chains

High-temperature durable polymer films with long-term atomic oxygen (AO) resistant capabilities are highly desired for the development of spacecraft with long-servicing lifetimes in low earth orbit (LEO). The relatively poor AO resistance of conventional polyimide (Kapton® H) film severely limited its applications in LEO spacecraft. In this work, carborane nanocage rich in boron element was introduced into polyimide molecular chain to prolong the atomic oxygen resistance life of polyimide film. A series of carborane-containing polyimide (CBPI) nanocomposite films with ultrahigh AO resistance have been prepared by casting precursor polyamic acid (PAA) solution on a glass plate, followed by thermal imidization at several elevated temperatures. The AO exposure experiments were tested in a ground-based AO effects simulation facility in our laboratory with the filament discharge and bound of magnetic field. Incorporation of carborane nanocage structure apparently improved the thermal stability and AO resistance of the PI nanocomposite films. The CBPI-50 film exhibited the lowest AO average erosion yield (Es) of 2.3 × 10−25 cm3·atom−1 under AO exposure with a fluence of 3.33 × 1020 atoms·cm−2, which is more than one order of magnitude lower than the reference Kapton® H film. The protective mechanism of CBPI nanocomposite films during AO exposure was proposed.

Biodegradable polymer everolimus-eluting stents versus contemporary drug-eluting stents: a systematic review and meta‑analysis

In spite of similar efficacy and safety in pilot studies, compared with the contemporary durable polymer drug-eluting stent (DP-DES), the bioabsorbable polymer drug-eluting stent (BP-DES) may be more superior in promoting blood vessel healing. We sought to compare the safety and efficacy of everolimus-eluting BP-DES (BP-EES) with contemporary DP-DES through a meta-analysis. We performed this meta-analysis to provide further evidence of the safety and efficacy of BP-EES. Medline, Embase and the Cochrane library databases were searched for randomized controlled trials comparing clinical efficacy and safety of BP-EES versus contemporary DP-DES. Fifteen RCTs with a total of 15,572 patients were selected. The rate of MACE was 9.4% in patients receiving BP-EES and 7.3% receiving DP-EES (RR 1.13, 95% CI 0.99–1.29, p = 0.05; I2 = 46%). TLF and MI were also similar in both groups. Based on the available data, this review demonstrates that BP-EES displays a clinically comparable efficacy and safety profile to that of contemporary DP-DES at years of follow-up in patients undergoing PCI.

Synthesis and exceptional operational durability of polyaniline-inspired conductive ladder polymers.

Ladder-type structures can impart exceptional stability to polymeric electronic materials. This article introduces a new class of conductive polymers featuring a fully ladder-type backbone. A judicious molecular design strategy enables the synthesis of a low-defect ladder polymer, which can be efficiently oxidized and acid-doped to achieve its conductive state. The structural elucidation of this polymer and the characterization of its open-shell nature are facilitated with the assistance of studies on small molecular models. An autonomous robotic system is used to optimize the conductivity of the polymer thin film, achieving over 7 mS cm-1. Impressively, this polymer demonstrates unparalleled stability in strong acid and under harsh UV-irradiation, significantly surpassing commercial benchmarks like PEDOT:PSS and polyaniline. Moreover, it displays superior durability across numerous redox cycles as the active material in an electrochromic device and as the pseudocapacitive material in a supercapacitor device. This work provides structural design guidance for durable conductive polymers for long-term device operation.

Physical and mechanical properties of anaerobic sealants

The article presents the main causes of wear on the seats of rolling bearings during operation, which are fretting corrosion and turning of the inner and outer rings of bearings. Installed that an effective way to protect metal surfaces from fretting corrosion is to place an intermediate medium between them. Coatings with a small modulus of elasticity are applied to one or both contacting surfaces to create an intermediate medium. Using anaerobic sealants as coatings with a small modulus of elasticity is recommended. Anaerobic sealants, which are multicomponent liquid compositions capable of remaining in the initial state for a long time without changing properties, quickly cure at temperatures of 20-25° C and in case of violation of contact with oxygen in the air with the formation of a durable solid polymer. The application technology of anaerobic sealants is presented, and the influence of temperature, talc, and copper on the physical and mechanical properties affecting the durability of fixed joints is studied. According to the results obtained, using the AN-6K and AN-103 brands of anaerobic sealants is recommended as the most effective for restoring fixed joints of rolling bearings and increasing their durability. The article substantiates the influence of temperature and various fillers on the physical and mechanical properties of anaerobic sealants; based on these results, the brands of sealants suitable for restoring fixed joints from rolling bearings are recommended.