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Lithium (Li)-O 2 batteries have triggered worldwide interest due to their ultrahigh theoretical energy density. However, it is a long shot for the grand-scale applications of Li-O 2 battery at current stage owing to its significant polarization, inferior cycling life, and irreversible decomposition of Li 2 O 2 . Herein, a facile way of preparing the highly dispersed Co-based nanoparticles encapsulated into porous N-doping carbon polyhedral with the low content of Ru modification (LRu@HDCo-NC) is explored through the pyrolysis of Co/Zn based zeolitic imidazole frameworks (ZIFs) containing Ru-based ligands. Even with the very small amount of Ru introduction (1.8%), LRu@HDCo-NC still exhibits the superior oxygen evolution reaction/oxygen reduction reaction (OER/ORR) performance and also inhibits side reactions in Li-O 2 battery because of the abundant pores, plentiful surface N heteroatoms, and highly dispersed metal-based sites which are induced by the volatilization of Zn, and conductive/stable carbon skeleton derived from ZIFs. When applied in Li-O 2 batteries, LRu@HDCo-NC cathode delivers a high discharge capacity of 15,973 mAh·g −1 at 200 mA·g −1 , good capacity retention at higher rate (12,362 mAh·g −1 at 500 mA·g −1 ) and outstanding stability for > 300 cycles with low voltage polarization of < 2.3 V under a cut-off capacity of 1,000 mAh·g −1 at 500 mA·g −1 . More critically, a series of ex situ and in situ characterization technologies disclose that the LRu@HDCo-NC cathodes can effectively promote the reversible reactions in Li-O 2 batteries.

Background Rapid and sensitive detection of H 2 O 2 especially endogenous H 2 O 2 is of great importance for series of industries including disease diagnosis and therapy. In this work, uniform FePt nanoparticles are successfully anchored onto Few-layer molybdenum disulfide nanosheets (F-MoS 2 NSs). The powder X-ray diffraction, transmission electron microscopy, UV–Vis spectra and atomic force microscopy were employed to confirm the structure of the obtained nanocomposites (F-MoS 2 -FePt NCs). The prepared nanocomposites show efficient peroxidase-like catalytic activities verified by catalyzing the peroxidation substrate 4,4′-diamino-3,3′,5,5′-tetramethylbiphenyl (TMB) with the existence of H 2 O 2 . Results The optimal conditions of the constructed colorimetric sensing platform is proved as 35 °C and pH 4.2. Under optimal catalytic conditions, the detection limit for H 2 O 2 detection reaches 2.24 μM and the linear ranger is 8 μM to 300 μM. Furthermore, the proposed colorimetric sensing platform was successfully utilized to detect the intracellular H 2 O 2 of cancer cells (MCF-7). Conclusions These findings indicated that the F-MoS 2 -FePt-TMB-H 2 O 2 system provides a potential sensing platform for hydrogen peroxide monitoring in living cells.

Highly stretched and conductive hydrogels, especially synthetized from natural polymers, are beneficial for highly stretched electronic equipment which is applied in extreme environment. We designed and prepared robust and tough alginate hydrogels (GMA-SA-PAM) using the ingenious strategy of fully interpenetrating cross-linking, in which the glycidyl methacrylate (GMA) was used to modify sodium alginate (SA) and then copolymerized with acrylamide (AM) and methylenebisacrylamide (BIS) as cross-linkers. The complete cross-linked structures can averagely dissipate energy and the polymer structures can maintain hydrogels that are three-dimensional to greatly improve the mechanical performance of hydrogels. The GMA-SA-PAM hydrogels display ultra-stretchable (strain up to ∼407% of tensile strain) and highly compressible (∼57% of compression strain) properties. In addition, soaking the GMA-SA-PAM hydrogel in 5 wt% NaCl solution also endows the conductivity of the hydrogel (this hydrogel was named as GSP-Na) with excellent conductive properties (5.26 S m ). The GSP-Na hydrogel with high stability, durability, as well as wide range extent sensor is also demonstrated by researching the electrochemical signals and showing the potential for applications in wearable and quickly responded electronics.

Objectives: This study aimed to assess the effects of storage temperature on the lipidomics profile change in Pacific saury (Cololabis saira). Methods: In this paper, C. saira underwent frozen storage at two different temperatures, T1 (−18 °C) and T2 (−25 °C), for a duration of three months. Chemical and lipidomic methods were used to determine the changes in lipids during the storage process. Results: Results showed that the content of triglyceride and phospholipid decreased significantly (p < 0.05), and free fatty acid increased significantly (p < 0.05), while the content of total cholesterol remained relatively constant across different storage temperatures. Additionally, an increasing trend in AV, POV, and TBARS contents was observed after the freezing process, with lipid oxidation being significantly higher in the −18 °C group compared to the −25 °C group (p < 0.05). A comprehensive analysis identified 4854 lipid molecules in the muscles of C. saira, categorized into 46 lipid subclasses, predominantly including triglycerides (TG), phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylglycerol (PG), and diglycerides (DG). Among them, TG was the most abundant lipid, followed by PC. Using orthogonal partial least squares discriminant analysis (OPLS-DA) with a variable importance in projection (VIP) score > 1 and p value < 0.05 as criteria, 338, 271, and 103 highly significantly differentiated lipids were detected in the comparison groups CK vs. T1, CK vs. T2, and T1 vs. T2, respectively. The results indicated that storage at −18 °C had a more pronounced effect than storage at −25 °C. During the freezing process, TG expression was significantly down-regulated, and TG(18:4_14:0_20:5), TG(20:5_13:0_22:6), TG(22:6_14:1_22:6), and TG(18:4_13:0_22:6) were the most predominant individuals. The CK group was initially present in C. saira before storage. Differential lipid molecules in the CK vs. T1 and CK vs. T2 groups were screened using a fold change (FC) > 2 or FC < 0.5. In the CK vs. T2 group, 102 highly significant differential lipid molecules were identified, with 55 being down-regulated across seven subclasses. In contrast, the CK vs. T1 group revealed 254 highly significant differential lipid molecules, with 85 down-regulated across 13 subclasses. The results showed that more PCs and PEs were down-regulated, with a higher differential abundance of PE and PC in the −25 °C group compared to the −18 °C group. The differential metabolites were primarily enriched in 17 metabolic pathways, with glycerophospholipid metabolism being the most prominent, followed by sphingolipid metabolism during the frozen storage. Conclusions: Overall, −25 °C storage in production was more favorable for maintaining the lipid stability of C. saira. This work could provide useful information for aquatic product processing and lipidomics.

Herein, three novel cocrystals of 1-hydroxy-2-naphthoic acid: tetramethylpyrazine, 1-hydroxy-2-naphthoic acid:1,10-phenanthroline, and 1-hydroxy-2-naphthoic acid:1,4-bis(imidazol-1-ylmethyl)benzene (L2) were obtained by crystallization in methanol–water mixed solvent via a slow evaporation method. The cocrystalline products 1−3 were carried out by a range of techniques, including single-crystal X-ray diffraction, Fourier transform–infrared spectroscopy, elemental analysis, and thermogravimetric testing. We analyzed the crystal structures of the cocrystals 1−3 and found that weak interactions C–H···X (X = O or π) were of great importance in the process of self-assembly as well as strong and conventional hydrogen bonds (N–H···O, O–H···N, O–H···O), leading to a stable and diverse multidimensional supramolecular architecture. It is worth noting that a series of ring motifs with different sizes were explored in the crystal structures of the above complexes, such as R22(5), R22(7), R22(8), R23(13), R24(16), R44(16), R44(22), and so on. The classical and robust supramolecular synthon intermolecular bond between acid and pyridine (acid···pyridine) heterosynthon R22(7), commonly found in organic solids containing carboxylic acids with other N-containing heteroaromatics, was further demonstrated to be involved in the construction of the hydrogen-bond networks of cocrystal 1. The thermogravimetric technique used in this study proved that the mass losses of these three cocrystals were closely related to the strength of the hydrogen bonds in the package fraction.

A series of well-defined thermoresponsive ABA-type triblock copolymers poly( N -isopropylacrylamide)- b -poly( n -octadecylacrylate)- b -poly( N -isopropylacrylamide) (PNIPAAm- b -PODA- b -PNIPAAm) consisting of two blocks of PNIPAAm and one block of PODA in different ratio are prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization. The structures of the copolymers are characterized by 1 HNMR. All block copolymers show lower critical micelle concentration (CMC) (<10 mg/L) in water, indicating the strong tendency of the triblock copolymers to self-assemble into highly stable micelles. It is interesting that the resulting micelles demonstrate double lower critical solution temperature (LCST) behavior. Dynamic light-scattering (DLS) experiments show that the micelles are well dispersed at nanoscale and have a narrow size distribution. Moreover, the drug-loading behavior of micelles is further investigated. The high drug encapsulation efficiency indicates the potential of micelles formed from PNIPAAm- b -PODA- b -PNIPAAm as drug carriers.

Two kinds of triblock copolymers based on N-isopropylacrylamide (NIPAAm) and ethyl acrylate(EA), PEA n -PNIPAAm m -PEA n (BAB type) and PNIPAAm m -PEA n -PNIPAAm m (ABA type) were prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization. Thermosensitive block polymer of PEA n -PNIPAAm m -PEA n (BAB type) and PNIPAAm m -PEA n -PNIPAAm m (ABA type) self-assembly form flower coronal and dendritic micelles in water solution with hydrophobic PEA as the core and hydrophilic PNIPAAm as the shell, respectively. Critical micelle concentration (CMC) can be obtained by measuring the surface tension of the copolymer. The study reveals that CMC of micelles are significantly affected by the monomer weight ratios of EA/NIPAAM in block copolymer and block in the order. The higher the content of the hydrophilic block, the smaller the copolymer CMC, and ABA-type with respect to the BAB-type has a smaller CMC value. Particle size of self-assembled micelles decreased first and then rapidly increased with the temperature increasing, surfactant SDS significantly affects the particle size of the polymer. By measuring the light transmission ratio of the copolymer solution, the effect of the lower critical solution temperature (LCST) in the salt solution was investigated, and it was also found that the higher content of the hydrophilic block, the higher LCST of copolymer.

This study describes the detailed investigation on dynamic swelling of biodegradable network system poly(N-isopropylacrylamide-co-N-maleylgelatin) P(NIPAAm-co-N-MAGEL) prepared by N-isopropylacrylamide (NIPAAm) and N-maleylgelatin (MAGEL) with N,N′-methylene bis(acrylamide) (BIS) as a cross-linking agent. Effects of MAGEL content on the swelling behavior were investigated. The results showed that the swelling kinetics were dependent on the content of MAGEL and the maximum swelling rate was observed at 30% content of MAGEL. The swelling process follows second-order kinetics, and the mechanism of water transport is pseudo-Fickian type of diffusion. Swelling kinetics under different concentrations of NaCl was also studied. The swelling rate decreased with increasing the concentration of NaCl.

Well-defined triblock copolymers poly( N -isopropylacrylamide)-b-poly(3-methacryloxypropyltrimethoxysilane)-b-poly( N -isopropylacrylamide) (PNIPAM-b-PMEMO-b-PNIPAM) with varying block ratios were successfully synthesized via reversible addition–fragmentation chain transfer polymerization. The amphiphilic triblock copolymers showed surfactant-like behavior in aqueous solution and could easily self-assemble into dendritic micelles with hydrophobic PMEMO as the core and hydrophilic PNIPAM as the shell when the copolymer concentration exceeded the critical micelle concentration (CMC). Transmittance measurements showed the triblock copolymers were thermosensitive, and it was worth noting that the lower critical solution temperature (LCST) values of copolymers exceeded pure PNIPAM to about 35.3 °C, which was very close to physiological temperature of human body. This was attributed to the effect of Si–O–CH 3 hydrolysis in polymers. The effect of a series of inorganic salts on thermosensitivity of PNIPAM-b-PMEMO-b-PNIPAM was investigated, and our results suggested that the block copolymers maintained good thermosensitivity in all salt solutions. The LCST did not change significantly in different concentrations of NaCl, CaCl 2 and MgCl 2 solutions, which proved the polymer had good salt resistance. Dynamic light scattering experiments showed that the micelles were well dispersed at about 120 nm below LCST with a small polydispersity index. In addition, the drug-loading experiments of micelles showed high drug encapsulation efficiency indicating their potential as drug carriers.

In this report, Platinum manganese nanoparticles (PtMn NPs) were attached onto Layered Double Hydroxide (LDH) via a facile in-situ growth strategy. Based on the prepared nanoparticles, a novel colorimetric sensor for fast and sensitive determination of H2O2 was established. The established colorimetric sensing platform exhibited perfect peroxidase-like activities confirmed by oxidating 4, 4'-Bi-2, 6-xylidine (TMB) with H2O2. The sensing platform was pH and temperature-dependent.