Ductile adhesive elastomers with force-triggered ultra-high adhesion strength.

Elastomers play a vital role in many forthcoming advanced technologies in which their adhesive properties determine materials' interface performance. Despite great success in improving the adhesive properties of elastomers, permanent adhesives tend to stick to the surfaces prematurely or result in poor contact depending on the installation method. Thus, elastomers with on-demand adhesion that is not limited to being triggered by UV light or heat, which may not be practical for scenarios that do not allow an additional external source, provide a solution to various challenges in conventional adhesive elastomers. Herein, we report a novel, ready-to-use, ultra high-strength, ductile adhesive elastomer with an on-demand adhesion feature that can be easily triggered by a compression force. The precursor is mainly composed of a capsule-separated, two-component curing system. After a force-trigger and curing process, the ductile adhesive elastomer exhibits a peel strength and a lap shear strength of 1.2 × 104 N m-1 and 7.8 × 103 kPa, respectively, which exceed the reported values for advanced ductile adhesive elastomers. The ultra-high adhesion force is attributed to the excellent surface contact of the liquid-like precursor and to the high elastic modulus of the cured elastomer that is reinforced by a two-phase design. Incorporation of such on-demand adhesion into an elastomer enables a controlled delay between installation and curing so that these can take place under their individual ideal conditions, effectively reducing the energy cost, preventing failures, and improving installation processes.

Composite Membrane for Sodium Polysulfide Hybrid Redox Flow Batteries.

Non-aqueous redox flow batteries (NARFBs) using earth-abundant materials, such as sodium and sulfur, are promising long-duration energy storage technologies. NARFBs utilize organic solvents, which enable higher operating voltages and potentially higher energy densities compared with their aqueous counterparts. Despite exciting progress throughout the past decade, the lack of low-cost membranes with adequate ionic conductivity and selectivity remains as one of the major bottlenecks of NARFBs. Here, we developed a composite membrane composed of a thin (<25 µm) Na+-Nafion coating on a porous polypropylene scaffold. The composite membrane significantly improves the electrochemical stability of Na+-Nafion against sodium metal, exhibiting stable Na symmetric cell performance for over 2300 h, while Na+-Nafion shorted by 445 h. Additionally, the composite membrane demonstrates a higher room temperature storage modulus than the porous polypropylene scaffold and Na+-Nafion separately while maintaining high Na+ conductivity (0.24 mS/cm at 20 °C). Our method shows that a composite membrane utilizing Na+-Nafion is a promising approach for sodium-based hybrid redox flow batteries.

Selective deconstruction of mixed plastics by a tailored organocatalyst.

Plastic represents an essential material in our society; however, a major imbalance between their high production and end-of-life management is leading to unrecovered energy, economic hardship, and a high carbon footprint. The adoption of plastic recycling has been limited, mainly due to the difficulty of recycling mixed plastics. Here, we report a versatile organocatalyst for selective glycolysis of diverse consumer plastics and their mixed waste streams into valuable chemicals. The developed organocatalyst selectively deconstructs condensation polymers at a specific temperature, and additives or other polymers such as polyolefin or cellulose can be readily separated from the mixed plastics, providing a chemical recycling path for many existing mixed plastics today. The Life Cycle Assessment indicates that the production of various condensation polymers from the deconstructed monomers will result in a significant reduction in greenhouse gas emissions and energy input, opening a new paradigm of plastic circularity toward a net-zero carbon society.

Direct­acting antiviral treatment is safe and effective for chronic HCV patients with psychiatric disorders.

Although most patients with hepatitis C virus (HCV) infection have been cured since the introduction of direct-acting antiviral (DAA) treatments, whether patients with psychiatric disorders and chronic HCV infection receive benefits from DAA treatments remain unclear. The efficacy and safety of DAA treatment were compared between patients with and without psychiatric disorders. Data were retrospectively collected from medical records at the Suzuka General Hospital (Japan) between September 2014 and December 2021. The study was an observational, single-center study. Fisher's exact test, Mann-Whitney U test and Friedman's test were used for the comparisons between groups. Patients with HCV infection who had been started on DAA treatments were included. In total, 15 HCV cases with psychiatric disorders (P) and 209 HCV cases with nonpsychiatric disorders (NP) were started on DAA treatments for HCV infection. Patients in group P were younger (55±13.9 years) compared with those in group NP (68±13.0 years). A total of 12 patients (80%) in group P achieved and 188 patients (90%) in group NP achieved sustained virologic response (SVR), with no significant difference between the two groups. The remaining three patients in group P who did not achieve SVR included two drop-out cases. Regarding the laboratory data at the end of DAA treatments and SVR, there were no significant differences between the two groups. There were no cases of discontinuation or reduction of medication due to psychiatric disorders during DAA treatment. DAA treatment for HCV infection is effective, tolerable and safe for psychiatric patients, as well as patients without psychiatric disorders. Psychiatric patients with HCV infection should undergo DAA treatment to prevent progression to liver failure and/or cancer.

Puncture-resistant self-healing polymers with multi-cycle adhesion and rapid healability.

The structural design of self-healing materials determines the ultimate performance of the product that can be used in a wide range of applications. Incorporating intrinsic self-healing moieties into puncture-resistant materials could significantly improve the failure resistance and product longevity, since their rapidly rebuilt bonds will provide additional recovery force to resist the external force. Herein, we present a series of tailored urea-modified poly(dimethylsiloxane)-based self-healing polymers (U-PDMS-SPs) that exhibit excellent puncture-resistant properties, fast autonomous self-healing, multi-cycle adhesion capabilities, and well-tunable mechanical properties. Controlling the composition of chemical and physical cross-links enables the U-PDMS-SPs to have an extensibility of 528% and a toughness of 0.6 MJ m-3. U-PDMS-SPs exhibit fast autonomous self-healability with 25% strain recovery within 2 minutes of healing, and over 90% toughness recovery after 16 hours. We further demonstrate its puncture-resistant properties under the ASTM D5748 standard with an unbreakable feature. Furthermore, the multi-cycle adhesive properties of U-PDMS-SPs are also revealed. High puncture resistance (>327 mJ) and facile adhesion with rapid autonomous self-healability will have a broad impact on the design of adhesives, roofing materials, and many other functional materials with enhanced longevity.

Recent development of end-of-life strategies for plastic in industry and academia: bridging their gap for future deployment.

Plastics have advanced society as a lightweight, inexpensive material of choice, and consequently over 400 million metric tons of plastics are produced each year. The difficulty with their reuse, due to varying chemical structures and properties, is leading to one of the major global challenges of the 21st century-plastic waste management. While mechanical recycling has been proven successful for certain types of plastic waste, most of these technologies can only recycle single types of plastics at a time. Since most recycling collection streams today have a mixture of different plastic types, additional sorting is required before the plastic waste can be processed by recyclers. To combat this problem, academics have devoted their efforts to developing technologies such as selective deconstruction catalysts or compatibilizer for commodity plastics and new types of upcycled plastics. In this review, the strengths and challenges of current commercial recycling processes are discussed, followed by examples of the advancement in academic research. Bridging a gap to integrate new recycling materials and processes into current industrial practices will improve commercial recycling and plastic waste management, as well as create new economies. Furthermore, establishing closed-loop circularity of plastics by the combined efforts of academia and industry will contribute toward establishing a net zero carbon society by significant reduction of carbon and energy footprints. This review serves as a guide to understand the gap and help to create a path for new discovery in academic research to be integrated into industrial practices.

A Novel Scoring System to Improve the Detection Efficiency of Pancreatic Cystic Lesions in the General Population.

Objective Pancreatic cystic lesions (PCLs) are known risk factors for pancreatic cancer. Therefore, this study explored the predictors identifying PCLs in a general population and developed a scoring system to help more efficiently diagnose these entities during medical checkups. Methods We reviewed 9,369 examinees of abdominal ultrasound (AUS) during medical checkups between January 2013 and November 2019. Predictors of PCLs were identified using a multivariate logistic regression analysis, and we constructed a scoring system based on these predictors. Results PCLs were detected in 118 (1.3%). Age 50-59 years old [odds ratio (OR) 2.52, 95% confidence interval (CI) 1.18-5.35], 60-69 years old (OR 3.91, 95% CI 1.86-8.26), and ≥70 years old (OR 10.5, 95% CI 5.03-21.7) as well as abdominal pain (OR 1.85, 95% CI 1.14-3.00), alcohol consumption (OR 1.72, 95% CI 1.03-2.89), a family history of pancreatic cancer (OR 2.41, 95% CI 1.09-5.34), and pre-diabetes or diabetes (OR 1.78, 95% CI 1.05-3.00) were predictors of PCLs. The following scores were assigned according to regression coefficients: age (50-59 years old, 1 point; 60-69 years old, 1.5 points; ≥70 years old, 2.5 points); abdominal pain, 1 point, alcohol consumption, 1 point; a family history of pancreatic cancer, 1 point; and pre-diabetes, 1 point. The PCL detection rate increased with the total score: 0.2% for total score 0 point, 5.4% for ≥4.0 points. The area under the curve of the scoring system was 0.75 (95% CI 0.70-0.79). Conclusion Our scoring system allows the risk of PCLs to be determined and may help more efficiently diagnose these entities.

Gastric Foveolar-type Adenocarcinoma with Raspberry-like Appearance in a Helicobacter pylori-uninfected Stomach: A Long-term Retrospective Follow-up of 16 Years.

Esophagogastroduodenoscopy in a 58-year-old man revealed a protruding lesion measuring 6 mm in diameter in the fornix. An endoscopic biopsy of the lesion indicated well-differentiated adenocarcinoma. The lesion was resected by polypectomy. According to the Japanese histologic diagnostic criteria, we made a final diagnosis of early gastric cancer (U, Gre, 6×6 mm, Type 0-I, tub1, pT1a (M), pUl0, Ly0, V0, pHM0, pVM0). A retrospective review of the endoscopic images showed that this lesion had already been present in the images taken 16 years ago. The size and morphology of the lesion were the same as those of the first detected lesion.

Intrinsically Self-Healing Polymers: From Mechanistic Insight to Current Challenges.

Self-healing materials open new prospects for more sustainable technologies with improved material performance and devices' longevity. We present an overview of the recent developments in the field of intrinsically self-healing polymers, the broad class of materials based mostly on polymers with dynamic covalent and noncovalent bonds. We describe the current models of self-healing mechanisms and discuss several examples of systems with different types of dynamic bonds, from various hydrogen bonds to dynamic covalent bonds. The recent advances indicate that the most intriguing results are obtained on the systems that have combined different types of dynamic bonds. These materials demonstrate high toughness along with a relatively fast self-healing rate. There is a clear trade-off relationship between the rate of self-healing and mechanical modulus of the materials, and we propose design principles of polymers toward surpassing this trade-off. We also discuss various applications of intrinsically self-healing polymers in different technologies and summarize the current challenges in the field. This review intends to provide guidance for the design of intrinsic self-healing polymers with required properties.

When does a macromolecule transition from a polymer chain to a nanoparticle?

Frequently, the defining characteristic of a nanoparticle is simply its size, where objects that are 1-100 nm are characterized as nanoparticles. However, synthetic and biological macromolecules, in particular high molecular weight chains, can satisfy this size requirement without providing the same phenomena as one would expect from a nanoparticle. At the same time, soft polymer nanoparticles are important in a broad range of fields, including understanding protein folding, drug delivery, vitrimers, catalysis and nanomedicine. Moreover, the recent flourish of all polymer nanocomposites has led to the synthesis of soft all-polymer nanoparticles, which emerge from internal crosslinking of a macromolecule. Thus, there exists a transition of an internally crosslinked macromolecule from a polymer chain to a nanoparticle as the amount of internal crosslinks increases, where the polymer chain exhibits different behavior than the nanoparticle. Yet, this transition is not well understood. In this work, we seek to address this knowledge gap and determine the transition of a macromolecule from a polymer chain to a nanoparticle as internal crosslinking increases. In this work, small angle neutron scattering (SANS) offers insight into the structure of polystyrene and poly(ethyl hexyl methacrylate) nanostructures in dilute solutions, with crosslinking densities that vary from 0.1 to 10.7%. Analyses of the SANS data provides structural characteristics to classify a nanostructure as chain-like or particle-like and identify a crosslinking dependent transition between the two morphologies. It was found that for both types of polymeric nanostructures, a crosslinking density of 0.81% (∼ a crosslink for every 1 in 125 monomers) or higher exhibit clear particle-like behavior. Lower crosslinking density nanostructures showed amounts of collapse similar to that of a star polymer (0.1% XL) or a random walk polymer chain (0.4% XL). Thus, the transition of an internally crosslinked macromolecule from a polymer chain to a nanoparticle is not an abrupt transition but occurs via the gradual contraction of the chain with incorporated crosslinks.

Closed-loop additive manufacturing of upcycled commodity plastic through dynamic cross-linking.

A sustainable closed-loop manufacturing would become reality if commodity plastics can be upcycled into higher-performance materials with facile processability. Such circularity will be realized when the upcycled plastics can be (re)processed into custom-designed structures through energy/resource-efficient additive manufacturing methods, especially by approachable and scalable fused filament fabrication (FFF). Here, we introduce a circular model epitomized by upcycling a prominent thermoplastic, acrylonitrile butadiene styrene (ABS) into a recyclable, robust adaptive dynamic covalent network (ABS-vitrimer) (re)printable via FFF. The full FFF processing of ABS-vitrimer overcomes the major challenge of (re)printing cross-linked materials and produces stronger, tougher, solvent-resistant three-dimensional objects directly reprintable and separable from unsorted plastic waste. This study thus offers an imminently adoptable approach for advanced manufacturing toward the circular plastics economy.

Upcycling of semicrystalline polymers by compatibilization: mechanism and location of compatibilizers.

With the continuous increase of global plastics production, there is a demand to develop energy efficient processes to transform mixed plastic wastes into new products with enhanced utility - a concept that is often referred to as upcycling. Compatibilization is one of the most promising strategies to upcycle communal waste plastics. In this work, poly(ethylene terephthalate) (PET) and high-density polyethylene (HDPE), both widely used semicrystalline packaging polymers, are used as the target polymer blend. We systematically evaluate and compare three commercial ethylene copolymer based compatibilizers, ELVALOY™ AC 2016 Acrylate Copolymer (EAA), ELVALOY™ PTW Copolymer (PTW), and SURLYN™ 1802 Ionomer (Surlyn). They represent different compatibilization mechanisms. Furthermore, this work tackles a challenging question: where the compatibilizers are located in the blend. We discover that the location of the compatibilizer molecules can be predicted by comparing the crystallinity change of PET and HDPE in binary and ternary systems. Gaining this knowledge will facilitate root cause analysis of an ineffective compatibilizer and guide the design strategy to upcycle commingled waste plastics.

Separator Effect on Zinc Electrodeposition Behavior and Its Implication for Zinc Battery Lifetime.

Uncontrolled zinc electrodeposition is an obstacle to long-cycling zinc batteries. Much has been researched on regulating zinc electrodeposition, but rarely are the studies performed in the presence of a separator, as in practical cells. Here, we show that the microstructure of separators determines the electrodeposition behavior of zinc. Porous separators direct zinc to deposit into their pores and leave "dead zinc" upon stripping. In contrast, a nonporous separator prevents zinc penetration. Such a difference between the two types of separators is distinguished only if caution is taken to preserve the attachment of the separator to the zinc-deposited substrate during the entire electrodeposition-morphological observation process. Failure to adopt such a practice could lead to misinformed conclusions. Our work reveals the mere use of porous separators as a universal yet overlooked challenge for metal anode-based rechargeable batteries. Countermeasures to prevent direct exposure of the metal growth front to a porous structure are suggested.

Design of tough adhesive from commodity thermoplastics through dynamic crosslinking.

Tough adhesives provide resistance against high debonding forces, and these adhesives are difficult to design because of the simultaneous requirement of strength and ductility. Here, we report a design of tough reversible/recyclable adhesive materials enabled by incorporating dynamic covalent bonds of boronic ester into commodity triblock thermoplastic elastomers that reversibly bind with various fillers and substrates. The spectroscopic measurements and density functional theory calculations unveil versatile dynamic covalent binding of boronic ester with various hydroxy-terminated surfaces such as silica nanoparticles, aluminum, steel, and glass. The designed multiphase material exhibits exceptionally high adhesion strength and work of debonding with a rebonding capability, as well as outstanding mechanical, thermal, and chemical resistance properties. Bonding and debonding at the interfaces dictate hybrid material properties, and this revelation of tailored dynamic interactions with multiple interfaces will open up a new design of adhesives and hybrid materials.

Ischemic hepatitis with infectious endocarditis: A case report.

A 58-year-old woman was admitted to Suzuka General Hospital with fever. She was diagnosed with infectious endocarditis based on the presence of anterior mitral leaflet vegetation on the echocardiography analysis and isolation of Pseudomonas guariconensis by blood culture. During treatment, the hepatic enzymes levels, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) were increased without any abdominal symptoms. Prolonged prothrombin time (PT) and prothrombin time international normalized ratio were observed, and acute hepatic failure was diagnosed. However, the hepatic injury resolved spontaneously with restoration of the PT value after the hepatic enzymes (AST, ALT, LDH and ALP) peaked. Diffusion-weighted imaging of hepatic magnetic resonance imaging showed diffuse high intensity of the entire liver except for part of the left lobe. The hepatic injury was diagnosed as ischemic hepatitis caused by embolization from the vegetation associated with infectious endocarditis. The recovery from hepatic ischemia was thought to be due to hepatic blood supply from extrahepatic collateral blood. After antibiotic treatment, the patient underwent resection of the vegetation on the anterior mitral valve leaflet. Hepatic artery occlusion is rare, but it may cause severe hepatic complications. During follow-up of infectious endocarditis, clinicians should be aware of the potential for whole organ ischemic damage caused by vessel occlusion, as well as hepatic ischemic damage.

Additive manufacturing of strong silica sand structures enabled by polyethyleneimine binder.

Binder Jet Additive Manufacturing (BJAM) is a versatile AM technique that can form parts from a variety of powdered materials including metals, ceramics, and polymers. BJAM utilizes inkjet printing to selectively bind these powder particles together to form complex geometries. Adoption of BJAM has been limited due to its inability to form strong green parts using conventional binders. We report the discovery of a versatile polyethyleneimine (PEI) binder for silica sand that doubled the flexural strength of parts to 6.28 MPa compared with that of the conventional binder, making it stronger than unreinforced concrete (~4.5 MPa) in flexural loading. Furthermore, we demonstrate that PEI in the printed parts can be reacted with ethyl cyanoacrylate through a secondary infiltration, resulting in an increase in flexural strength to 52.7 MPa. The strong printed parts coupled with the ability for sacrificial washout presents potential to revolutionize AM in various applications including construction and tooling.

Polymers with Dynamic Bonds: Adaptive Functional Materials for a Sustainable Future.

Polymeric materials play critical role in many current technologies. Among them, adaptive polymeric materials with dynamic (reversible) bonds exhibit unique properties and provide exciting opportunities for various future technologies. Dynamic bonds enable structural rearrangements in polymer networks in specific conditions. Replacement of a few covalent bonds by dynamic bonds can enhance polymeric properties, e.g., strongly improve the toughness and the adhesive properties of polymers. Moreover, they provide recyclability and enable new properties, such as self-healing and shape memory effects. We briefly overview new developments in the field of polymers with dynamic bonds and current understanding of their dynamic properties. We further highlight several examples of unique properties of polymers with dynamic bonds and provide our perspectives for them to be used in many current and future applications.

Early stage clear cell adenocarcinoma coexisting with tubular adenoma and adenoma with clear cell change in the colon.

Primary clear cell adenocarcinoma (CCA) of the colorectum is rare. We report a case of a 57-year-old man with early-stage CCA with conventional tubular adenoma and tubular adenoma with clear cell change in the transverse colon, diagnosed with image-enhanced endoscopy. The tumor was then treated with endoscopic submucosal dissection. The endoscopic findings characteristic of clear cell adenoma/adenocarcinoma could not be identified. Therefore, similar diagnostic tools as for conventional colorectal adenoma/cancer were considered. The pathogenesis of the clear cell change was unknown, but it might appear with the progression of the malignancy.

Turning Rubber into a Glass: Mechanical Reinforcement by Microphase Separation.

Supramolecular associations provide a promising route to functional materials with properties such as self-healing, easy recyclability or extraordinary mechanical strength and toughness. The latter benefit especially from the transient character of the formed network, which enables dissipation of energy as well as regeneration of the internal structures. However, recent investigations revealed intrinsic limitations in the achievable mechanical enhancement. This manuscript presents studies of a set of telechelic polymers with hydrogen-bonding chain ends exhibiting an extraordinarily high, almost glass-like, rubbery plateau. This is ascribed to the segregation of the associative ends into clusters and formation of an interfacial layer surrounding these clusters. An approach adopted from the field of polymer nanocomposites provides a quantitative description of the data and reveals the strongly altered mechanical properties of the polymer in the interfacial layer. These results demonstrate how employing phase separating dynamic bonds can lead to the creation of high-performance materials.

The spontaneous clearance of hepatitis E virus (HEV) and emergence of HEV antibodies in a transfusion-transmitted chronic hepatitis E case after completion of chemotherapy for acute myeloid leukemia.

A 64-year-old woman was infected with hepatitis E virus (HEV) during chemotherapy for leukemia. By retrospective analyses of stored serum from the blood products and the patient, the source of the infection was determined to be platelet concentration (PC) transfused during chemotherapy. The partial nucleotide sequence of the HEV strain isolated from the donated PC and that from the patient's sera was identical and was subgenotype 3b. Clinical indicators such as alanine aminotransferase, HEV RNA titer, and anti-HEV antibodies in the serum were investigated from the beginning of the infection until 1 year after the termination of HEV infection. HEV RNA had propagated over 6 months and then cleared spontaneously after the completion of chemotherapy. Anti-HEV antibodies appeared in the serum just before the clearance of HEV RNA. Interestingly, HEV RNA was detected in the patient's urine, spinal fluid, and saliva. The HEV RNA titers in those samples were much lower than in the serum and feces. No renal, neurological, or salivary gland disorders appeared during the follow-up. We observed virological and biochemical progress and cure of transfusion-transmitted chronic hepatitis E in the patient despite an immunosuppressive status during and after chemotherapy against hematological malignancy.