Search

Chemical recycling to monomer (CRM) provides an ideal solution for reducing plastic waste and achieving a circular polymer economy. Cyclopentene (CP) and its derivatives are representative molecules that exemplify an efficient CRM process under mild conditions. However, most CP‐based polymers possess limited thermal and mechanical properties, constraining their potential applications. Herein, new CP‐based polymers with superior thermo‐mechanical properties and autonomous functions are proposed by integrating anthracene as a dynamic functional motif. Anthracenes not only serve as supramolecular cross‐linkages through strong π–π interactions but also form stronger chemical ones under UVA light irradiation, enhancing thermo‐mechanical properties. Furthermore, damage‐reporting, self‐healing, and local shape reprogramming capabilities are accomplished by utilizing the reversible nature of photodimerized anthracene. A mild and orthogonal depolymerization condition for the CP‐based polymers facilitates efficient monomer recovery even from mixed plastic wastes. This work presents a simple yet effective strategy to expand the usability of chemically recyclable polymers and contribute to a closed‐loop polymer economy. [ABSTRACT FROM AUTHOR]

The gut microbiome is closely linked to gastrointestinal health and disease status. Oral administration of known probiotic strains is now considered a promising therapeutic strategy, especially for refractory diseases such as inflammatory bowel disease. In this study, we developed a nanostructured hydroxyapatite/alginate (HAp/Alg) composite hydrogel that protects its encapsulated probiotic Lactobacillus rhamnosus GG (LGG) by neutralizing hydrogen ions that penetrate the hydrogel in a stomach without inhibiting LGG release in an intestine. Surface and transection analyses of the hydrogel revealed characteristic patterns of crystallization and composite‐layer formation. TEM revealed the dispersal of the nanosized HAp crystals and encapsulated LGG in the Alg hydrogel networks. The HAp/Alg composite hydrogel maintained its internal microenvironmental pH, thereby enabling the LGG to survive for substantially longer. At intestinal pH, the encapsulated LGG was completely released upon disintegration of the composite hydrogel. In a dextran sulfate sodium‐induced colitis mouse model, we then assessed the therapeutic effect of the LGG‐encapsulating hydrogel. This achieved intestinal delivery of LGG with minimal loss of enzymatic function and viability, ameliorating colitis by reducing epithelial damage, submucosal edema, inflammatory cell infiltration, and the number of goblet cells. These findings reveal the HAp/Alg composite hydrogel as a promising intestinal‐delivery platform for live microorganisms including probiotics and live biotherapeutic products. [ABSTRACT FROM AUTHOR]

Keeping both the chemical and physical state of the electrode–electrolyte interface intact is one of the greatest challenges in achieving solid‐state batteries (SSBs) with longer cycle lives. Herein, the use of organic electrolyte additives in the cathode electrolyte interphase (CEI) layer to mitigate the intertwined chemical and mechanical degradation in sulfide‐based SSBs is demonstrated. Lithium difluorobis(oxalato)phosphate (LiDFBOP) and argyrodite (Li6PS5Cl) are used as a model system, with the LiDFBOP‐derived CEI layer induced by irreversible oxidation above 4.12 V (vs Li+/Li) during the formation cycle exhibiting dual functions. This CEI layer retards the rate of chemical degradation between the cathode active particles and solid electrolytes at high charging potential and helps maintain intimate physical contact even at a low stack pressure of 0.75 MPa. The improved physical contact enables delivery of a high initial capacity, while chemical stability suppressing the sulfite or sulfate formation has a more dominant effect on the long‐term cycle stability. This study presents a new perspective and strategies for designing cathode coating materials for sulfide‐based SSBs beyond the typically used inorganic oxide materials. [ABSTRACT FROM AUTHOR]

The aim of this study was to find the appropriate level of goat milk protein powder (GMPP) and ginseng powder (GP) as natural binding agent and antioxidant added for emulsion-type pork sausages. Six groups of pork sausages were prepared: (1) pork sausage with 0.2% phosphate and 0.1% ascorbic acid (C2), (2) negative control (C3), (3) with 0.2% GMPP and 0.1% GP (T1), (4) 0.2% GMPP and 0.3% GP (T2), (5) 0.4% GMPP and 0.1% GP (T3), and (6) 0.4% GMPP and 0.3% GP (T4). Proximate analysis, water holding capacity (WHC), emulsion stability, cooking loss, color, texture properties, and sensory properties of sausages were performed. pH, DPPH radical scavenging, thiobarbituric acid reactive substance (TBARS), volatile basic nitrogen (VBN), and total microbial count (TMC) were measured for pork sausages after storage at 4°C for 0, 7, 14, and 21 days. The results showed that water and total exudation showed significantly lower values in T3. Cooking loss also showed a significantly lower value in T3. T3 showed a significantly higher value of springiness of textural properties than C2. With increasing level of GMPP added, protein content and pH value of pork sausages were also increased. There were no significant differences in WHC or sensory properties between C2 and T3. TBARS and VBN values of T3 were significantly lower than those of other experimental groups during all storage periods. T3 presented higher DPPH radical scavenging values during all storage periods. These results indicate that adding 0.4% GMPP and 0.1% GMPP can effectively improve quality and storage characteristics of pork sausages. [ABSTRACT FROM AUTHOR]

This study evaluated the physicochemical characteristics and storage stability (at 0, 3, and 7 days) of hybrid beef patties with different amount of shiitake mushrooms (Lentinus edodes) added. Shiitake mushrooms contain healthy ingredients such as ergosterol and β-glucan. Four proportions of shiitake mushrooms were added to beef patties (T1, 20%, T2, 40%, T3, 60%, T4, 80%) as a substitute for beef and compared with a control group (CON 0%). Chemical composition, water holding capacity (WHC), cooking loss, pH, color, texture profile analysis, and sensory properties of the products were compared on day 0. As a storage stability experiment, volatile basic nitrogen (VBN), 2-thiobarbituric acid reactive substances (TBARS), and total microbial count were compared (0, 3, and 7 days). The results revealed that replacement with shiitake improved the WHC and cooking loss of patties but had a negative effect on sensory properties and storage stability. These results indicate that shiitake mushrooms can be added along with beef to produce hybrid patties; however, the usage amount must be considered. [ABSTRACT FROM AUTHOR]

By combining bifunctional diglycidyl ether of bisphenol A (DGEBA) and trifunctional tris(4‐hydroxyphenyl) methane triglycidyl ether (TMTE) epoxy monomers, along with 4,4′‐dithiodibutyric acid (DTDBA) as a carboxylic acid, a variety of novel reprocessable and recyclable thermoset polymers are synthesized. The crosslinked network structures with different crosslinking densities are produced by changing the mixing ratio between DGEBA and TMTE, resulting in changes in mechanical and thermal properties of the final products. The stress relaxation and self‐healing experiments confirmed that all of these polymeric materials have covalent adaptable networks in their microstructures and perform reversible transesterification processes inside a polymer network. These thermoset polymers are completely decomposed in solution by disulfide‐thiol reduction of DTDBA with reversible cleavage or coupling capability in the presence of reducing agent, allowing chemical recycling capability into the thermoset polymer network. [ABSTRACT FROM AUTHOR]

N‐Acetylserotonin (NAS) is an intermediate in the melatonin biosynthetic pathway. We investigated the anti‐inflammatory activity of NAS by focusing on its chemical feature oxidizable to an electrophile. NAS was readily oxidized by reaction with HOCl, an oxidant produced in the inflammatory state. HOCl‐reacted NAS (Oxi‐NAS), but not NAS, activated the anti‐inflammatory nuclear factor erythroid 2‐related factor 2 (Nrf2)‐heme oxygenase (HO)‐1 pathway in cells. Chromatographic and mass analyses demonstrated that Oxi‐NAS was the iminoquinone form of NAS and could react with N‐acetylcysteine possessing a nucleophilic thiol to form a covalent adduct. Oxi‐NAS bound to Kelch‐like ECH‐associated protein 1, resulting in Nrf2 dissociation. Moreover, rectally administered NAS increased the levels of nuclear Nrf2 and HO‐1 proteins in the inflamed colon of rats. Simultaneously, NAS was converted to Oxi‐NAS in the inflamed colon. Rectal NAS mitigated colonic damage and inflammation. The anticolitic effects were significantly compromised by the coadministration of an HO‐1 inhibitor. [ABSTRACT FROM AUTHOR]

Stochastic weight averaging (SWA) was applied to improve the radiation emulator based on a sequential neural network (SNN) in a numerical weather prediction model over Korea. While the SWA has advantages in terms of generalization such as the ensemble model, the computational cost is maintained at the same level as that of a single model. In this study, the performances of both emulators were evaluated under ideal and real case frameworks. Various sensitivity experiments using different sampling ratios, activation functions, hidden layers, and batch sizes were also conducted. The emulators showed a 60‐fold speedup for the radiation processes and 84%–87% reduction of the total computation. In the ideal simulation, compared to the infrequent radiation scheme by 60 times, SNN improved forecast errors by 5.8%–14.1%, and SWA further increased these improvements by 18.2%–26.9%. In the real case simulation, SNN showed 8.8% and 4.7% improvements for longwave and shortwave (SW) fluxes compared to the infrequent method; however, these improvements decreased significantly after 5 days, resulting in 1.8% larger error for skin temperature. By contrast, SWA showed stable 1‐week forecast features with 12.6%, 8.0%, and 4.4% improvements in longwave and SW fluxes, and skin temperature, respectively. Although the use of two hidden layers showed the best performance in this study, it was thought that the optimal number of hidden layers could differ depending on the given problem. Compared to temperature and precipitation observations, all experiments showed a variability of error within 1%, implying that the operational use of the developed emulators is possible. Plain Language Summary: The neural network (NN) emulators for radiation parameterization have been actively developing to accelerate the computational speed of the numerical climate and weather forecasting models. Although previous studies have demonstrated that the computational speed for radiation processes can be improved tens of times, guaranteeing stability in long‐term forecasting has been recognized as imperative for the operational use of radiation emulator. In general, the multi‐model ensemble approach is used to reduce the uncertainty of a single model. However, this approach induces a significant computation burden in proportion to ensemble members. The alternative method developed in this study uses a stochastic averaging technique for weight coefficients during the NN training process, allowing processing to be conducted at the same computational cost as the single model because the dimensions of the final weights are maintained. Application of the trained NN emulator to the numerical weather forecasting model has demonstrated the advantages of generalization in various test cases, while exhibiting significant improvements in accuracy in the latter part of the forecast. This method can therefore contribute to improving emulator studies that face problems related to generalization. Key Points: The performance of the neural network (NN) radiation scheme was evaluated under ideal and real case frameworksStochastic weight averaging is advantageous in generalization compared to the traditional NNLong‐term forecast errors can be largely improved using stochastic weight averaging [ABSTRACT FROM AUTHOR]

A new structural phase is discovered for M2CO2 MXenes with M = Sc, Y, La, Lu, Tm, and Ho. The hexagonal carbon layer sandwiched between M atoms, typical for MXenes, is transformed into C3 trimers with anionic electrons localized in quasi zero‐dimensional lattice spaces in‐between the C3 units, so the systems can be described as [M6 C3 O6]+II : 2e− electrides. The systems are readily ionized into [M6 C3 O6]+II with very low ionization energy via an anti‐doping mechanism. It is shown that this new structure of Sc2CO2 can bind multiple lithium atoms, with low migration barriers. The findings indicate that these M2CO2 MXenes with unusual carbon trimers are a new family of 2D electride insulators with the potential for charge storage applications, thermal field emission, and as anode material in lithium batteries. [ABSTRACT FROM AUTHOR]

While the Landauer viewpoint constitutes a modern basis to understand nanoscale electronic transport and to realize first‐principles implementations of the nonequilibrium Green's function (NEGF) formalism, seeking an alternative picture can be beneficial for the fundamental understanding and practical calculations of quantum transport processes. Herein, introducing a micro‐canonical picture that maps the finite‐bias quantum transport process to a drain‐to‐source or multi‐electrode optical excitation, the multi‐space constrained‐search density functional theory (MS‐DFT) formalism for first‐principles electronic structure and quantum transport calculations is developed. Performing MS‐DFT calculations for the benzenedithiolate single‐molecule junction, it is shown that MS‐DFT and standard DFT‐NEGF calculations produce practically equivalent electronic and transmission data. Importantly, the variational convergence of "nonequilibrium total energy" within MS‐DFT is demonstrated, which should have significant implications for in operando studies of nanoscale devices. Establishing a viable alternative to the Landauer viewpoint, the developed formalism should provide valuable atomistic information in the development of next‐generation nanodevices. [ABSTRACT FROM AUTHOR]

Abstract: While one of the most promising applications of carbon nanotubes (CNTs) is to enhance polymer orientation and crystallization to achieve advanced carbon fibers, the successful realization of this goal has been hindered by the insufficient atomistic understanding of polymer–CNT interfaces. Herein, polyacrylonitrile (PAN)‐CNT hybrid structures are theoretically studied as a representative example of polymer–CNT composites. Based on density functional theory calculations, it is first found that the relative orientation of polar PAN nitrile groups with respect to the CNT surface is the key factor that determines the PAN–CNT interface energetics and the lying‐down PAN configurations are much more preferable than their standing‐up counterparts. The CNT curvature is identified as another important factor, giving the largest binding energy in the zero‐curvature graphene limit. Charge transfer analysis explains the unique tendency of linear PAN alignments on the CNT surface and the possibility of ordered PAN–PAN assembly. Next, performing large‐scale molecular dynamics simulations, it is shown that the desirable linear PAN–CNT alignment can be achieved even for relatively large initial misorientations and further demonstrate that graphene nanoribbons are a promising carbon nano‐reinforcement candidate. The microscopic understanding accumulated in this study will provide design guidelines for the development of next‐generation carbon nanofibers. [ABSTRACT FROM AUTHOR]

Background: Given recent interest in using amyloid b (Aβ)‐targeted antibodies as a therapy for patients with Alzheimer's disease (AD), removal of Aβ by phagocytosis likely protective early in AD. Impaired phagocytic function of glial cells surrounding Aβ plaques during later stages in AD likely contributes to worsened disease outcomes, therefore enhancing phagocytic activity of glial cells could be a potent strategy for AD therapy. Method: Changes in TMEM176B expression according to the progression of AD pathology was assessed by measuring TMEM176B protein in human AD brain lysates and TMEM176B transcripts in Ab‐treated primary rat astrocytes. The roles of TMEM176B in phagosome maturation of glial cells was investigated by measuring Rab5, Rab7, LAMP1, LAMP2, cathepsin D, and LC3B in presence of Aβ. Intracellular pH of glial cells was detected using fluorescent dye‐based pHrodo Red AM intracellular pH indicator (Invitrogen, Carlsbad, CA). In 5xFAD and 3xTg AD mice model, therapeutic effects of AAV‐TMEM176B was examined. AAV (adenovirus‐associated virus)‐TMEM176B (1 – 2×1010 GC) was intracerebroventricularly injected, and Aβ plaque and p‐tau in brains were assessed 3 months later. Behavioral studies such as Y‐maze, Morris water maze, and novel‐object‐recognition were conducted to exam the effect of TMEM176B overexpression in alleviation of cognition decline. Result: In human AD brains, Tmem176B expression was increased in moderate AD (Braak III‐IV) was decreased in severe AD (Braak V‐VI). TMEM176B was upregulated by acute Aβ treatment in primary rat astrocytes, and was gradually downregulated concomitantly with impairment of Aβ phagocytosis activity by chronic exposure to Aβ. The TMEM176B agonistic compound augmented phagosome maturation and phagosomal acidification, which led to increased Aβ phagocytosis and lysosomal degradation. Studies confirmed that intracerebroventrical administration of AAV carrying TMEM176B in AD mice results in enhanced glial phagocytosis followed by lowered Aβ burden in brain. Moreover, overexpression of TMEM176B by AAV injection significantly improved cognition impairment of AD mice. Conclusion: Data from these studies suggest that TMEM176B plays a direct and critical role in phagolysosmal function of glial cells and AD pathogenesis and highlight this ion channel as a potential therapeutic target for treating AD. [ABSTRACT FROM AUTHOR]

Pyrotechnic release devices such as explosive bolts are prevalent for many applications due to their merits: high reliability, high power-to-weight ratio, reasonable cost, and more. However, pyroshock generated by an explosive event can cause failures in electric components. Although pyroshock propagations are relatively well understood through many numerical and experimental studies, the prediction of pyroshock generation is still a very difficult problem. This study proposes a numerical method for predicting the pyroshock of a ridge-cut explosive bolt using a commercial hydrocode (ANSYS AUTODYN). A numerical model is established by integrating fluid-structure interaction and complex material models for high explosives and metals, including high explosive detonation, shock wave transmission and propagation, and stress wave propagation. To verify the proposed numerical scheme, pyroshock measurement experiments of the ridge-cut explosive bolts with two types of surrounding structures are performed using laser Doppler vibrometers (LDVs). The numerical analysis results provide accurate prediction in both the time (acceleration) and frequency domains (maximax shock response spectra). In maximax shock response spectra, the peaks due to vibration modes of the structures are observed in both the experimental and numerical results. The numerical analysis also helps to identify the pyroshock generation source and the propagation routes. [ABSTRACT FROM AUTHOR]

Background: Glycine transporter 1 (GlyT1), expressed predominantly in astrocytes, is responsible for the glycine reuptake from the synaptic cleft in the central nervous system. Since glycine exerts dual effects on inhibitory neurotransmission and excitatory neuromodulation as a co‐activator of NMDA receptor, rapid clearance of glycine in a submicromolar range through GlyT1 is important to terminate neuronal signaling. Also, as glycine uptake by GlyT1 is coupled to 2 Na+ and 1 Cl−, the accumulation of glycine in the brain could be toxic due to dysregulation of glycine‐induced metabotropic signaling pathways. Previous reports show that glycine concentration is elevated in the cerebrospinal fluid (CSF) of patients with Alzheimer's disease (AD). It could alter glial function which is important for neuroprotection through Aβ phagocytosis. Method: We performed immunohistochemistry with human AD brain to evaluate the GlyT1 expression in the astrocytes. Then, we used an adeno‐associated viral vector (AAV) to overexpress GlyT1 in the brains of AD model mice and conducted water‐maze and Y‐maze to test the cognitive function. Result: We found that GlyT1 is downregulated in the human AD brain, especially in the astrocytes adjacent to the Aβ plaques. Overexpression of GlyT1 in the brain by AAV‐GlyT1 injcetion alleviates the cognitive impairment of AD model mice. Also, phagocytic activity of the astrocytes and microglia in GlyT1‐overexpressed mice brains is increased, suggesting GlyT1‐mediated glycine uptake restores the glial function. Consistently, in vitro experiments show that a high concentration of glycine reduces Aβ phagocytosis of human astrocyte and microglia cell lines, and GlyT1 overexpression rescues the glial function. Also, glycine induces internalization of GlyRs resulting in intracellular Ca2+ accumulation. Conclusion: Our results demonstrate the important role of GlyT1 in glial function in the brain and propose GlyT1 as a novel therapeutic target for Alzheimer's disease. [ABSTRACT FROM AUTHOR]

In article number 1807620, Yong‐Hoon Kim and co‐workers show that the PbI3 nanowire, the inorganic framework of trimethylsulfonium lead triiodide (TMSPbI3) perovskite, assumes a semi‐metallic character, and displays excellent negative differential resistance (NDR) characteristics emerging from the PbI3‐TMSPbI3‐PbI3 junctions through the novel quantum‐hybridization NDR mechanism. [ABSTRACT FROM AUTHOR]

In the rapidly progressing field of organometal halide perovskites, the dimensional reduction can open up new opportunities for device applications. Herein, taking the recently synthesized trimethylsulfonium lead triiodide (CH3)3SPbI3 perovskite as a representative example, first‐principles calculations are carried out and the nanostructuring and device application of halide perovskite nanowires are studied. It is found that the 1D (CH3)3SPbI3 structure is structurally stable, and the electronic structures of higher‐dimensional forms are robustly determined at the 1D level. Remarkably, due to the face‐sharing [PbI6] octahedral atomic structure, the organic ligand‐removed 1D PbI3 frameworks are also found to be stable. Moreover, the PbI3 columns avoid the Peierls distortion and assume a semimetallic character, contradicting the conventional assumption of semiconducting metal‐halogen inorganic frameworks. Adopting the bundled nanowire junctions consisting of (CH3)3SPbI3 channels with sub‐5 nm dimensions sandwiched between PbI3 electrodes, high current densities and large room‐temperature negative differential resistance (NDR) are finally obtained. It will be emphasized that the NDR originates from the combination of the near‐Ohmic character of PbI3‐(CH3)3SPbI3 contacts and a novel NDR mechanism that involves the quantum‐mechanical hybridization between channel and electrode states. This work demonstrates the great potential of low‐dimensional hybrid perovskites toward advanced electronic devices beyond actively pursued photonic applications. The unique semimetallicity and negative differential resistance (NDR) characteristics can be derived from organic–inorganic halide perovskite nanowires. The PbI3 nanowire, the inorganic framework of trimethylsulfonium lead triiodide (TMSPbI3), is found to assume a semimetallic character by avoiding the Peierls distortion. Excellent NDR characteristics are predicted to arise from the TMSPbI3‐PbI3 nanowire junctions with near‐Ohmic contacts through a novel quantum‐hybridization NDR mechanism. [ABSTRACT FROM AUTHOR]

We propose two link-layer reliable broadcast protocols for wireless sensor networks based on IEEE 802.15.5. We compare them in terms of energy consumption. By including both positive and negative acknowledgement, our second proposed scheme can effectively reduce the number of unnecessary error control messages and, thereby, significantly reducing the unnecessary power consumption relative to the first scheme. Also, we provide an analytical framework for the evaluation of different reliable broadcast techniques. Simulation results show that Scheme 2 achieves energy savings of up to about 85% compared to Scheme 1. [ABSTRACT FROM AUTHOR]