2D Conjugated Metal-Organic Frameworks Bearing Large Pore Apertures and Multiple Active Sites for High-Performance Aqueous Dual-Ion Batteries.

2D conjugated metal-organic frameworks (2D c-MOFs) with large pore sizes and high surface areas are advantageous for adsorbing iodine species to enhance the electrochemical performance of aqueous dual-ion batteries (ADIBs). However, most of the reported 2D c-MOFs feature microporous structures, with few examples exhibiting mesoporous characteristics. Herein, we developed two mesoporous 2D c-MOFs, namely PA-TAPA-Cu-MOF and PA-PyTTA-Cu-MOF, using newly designed arylimide based multitopic catechol ligands (6OH-PA-TAPA and 8OH-PA-PyTTA). Notably, PA-TAPA-Cu-MOF exhibits the largest pore sizes (3.9 nm) among all reported 2D c-MOFs. Furthermore, we demonstrated that these 2D c-MOFs can serve as promising cathode host materials for polyiodides in ADIBs for the first time. The incorporation of triphenylamine moieties in PA-TAPA-Cu-MOF resulted in a higher specific capacity (423.4 mAh g-1 after 100 cycles at 1.0 A g-1) and superior cycling performance, retaining 96% capacity over 1000 cycles at 10 A g-1 compared to PA-PyTTA-Cu-MOF. Our comparative analysis revealed that the increased number of N anchoring sites and larger pore size in PA-TAPA-Cu-MOF facilitate efficient anchoring and conversion of I3-, as supported by spectroscopic electrochemistry and density functional theory calculations.

Epoxy-rich Fe Single Atom Sites Boost Oxygen Reduction Electrocatalysis.

Electrocatalysts for highly efficient oxygen reduction reaction (ORR) are crucial for energy conversion and storage devices. Single-atom catalysts with maximized metal utilization and altered electronic structure are the most promising alternatives to replace current benchmark precious metals. However, the atomic level understanding of the functional role for each species at the anchoring sites is still unclear and poorly elucidated. Herein, we report Fe single atom catalysts with the sulfur and oxygen functional groups near the atomically dispersed metal centers (Fe1/NSOC) for highly efficient ORR. The Fe1/NSOC delivers a half-wave potential of 0.92 V vs. RHE, which is much better than those of commercial Pt/C (0.88 V), Fe single atoms on N-doped carbon (Fe1/NC, 0.89 V) and most reported nonprecious metal catalysts. The spectroscopic measurements reveal that the presence of sulfur group induces the formation of epoxy groups near the FeN4S2 centers, which not only modulate the electronic structure of Fe single atoms but also participate the catalytic process to improve the kinetics. The density functional theory calculations demonstrate the existence of sulfur and epoxy group engineer the charges of Fe reactive center and facilitate the reductive release of OH* (rate-limiting step), thus boosting the overall oxygen reduction efficiency.

Atomically dispersed Mn atoms coordinated with N and O within an N-doped porous carbon framework for boosted oxygen reduction catalysis.

Developing efficient and robust catalysts to replace Pt group metals for the oxygen reduction reaction (ORR) is conducive to achieving highly efficient energy conversion. Here, we develop a general ion exchange strategy to construct highly efficient ORR catalysts consisting of various atomically dispersed metal atoms anchored on N-doped porous carbon (M-SAs/NC) to investigate the atomic structure-catalytic activity relationship. The structure characterization results demonstrated that the achieved atomic structure varied due to the presence of different metal centers. Mn-SAs/NC consists of MnN3O1 centers, in which the Mn single atoms are stabilized by 3 N and 1 O. In contrast, the center metals in Fe-/Co-/Cu single-atom catalysts are coordinated by merely N atoms. Mn-SAs/NC delivers superior performance for the ORR with a half-wave potential (E1/2) of 0.91 V vs. RHE in 0.1 M KOH solution, outperforming that of the commercial Pt/C catalyst and the control Fe-/Co-/Cu single-atom catalysts. Furthermore, Mn-SAs/NC also shows excellent methanol tolerance and stability up to 5000 cycles. Density functional theory (DFT) calculations reveal that Mn single atom catalysts with MnN3O1 centers contributed to the superior ORR performance with lower energy barriers and optimized adsorption capacity of intermediates. These findings provide insights into the design and development of specific coordinated structures of atomically dispersed catalysts to facilitate the practical applications of energy conversion.

Peripheral T lymphocyte and immunocyte subset dynamics: markers of neoadjuvant therapy outcomes in esophageal squamous cell carcinoma.

Purpose: In patients with resectable esophageal squamous cell carcinoma (ESCC), neoadjuvant therapy increased the curative resection rate, disease-free survival, and overall survival for patients with resectable ESCC. However, the efficacy of neoadjuvant therapy varies among different patients. We aim to compare the differences in the characteristics of peripheral blood T lymphocyte subsets before and after neoadjuvant therapy in patients with different curative efficacy. Method: This study enrolled 266 ESCC patients who received neoadjuvant therapy and esophagectomy from August 2018 to August 2022. The postoperative pathological results divided patients into the major pathological response (MPR) and non-MPR groups. Compare the differences in peripheral blood T lymphocyte subsets and analyze the trend of changes in T lymphocyte subsets at different phases of treatment. Propensity score matching was used to reduce the influence of potential confounding factors. Results: Prior to the neoadjuvant therapy, particularly before the second cycle, the MPR group exhibited significantly higher ratios of CD4/CD8 (P=0.009) and helper T cells (TH ratio, P=0.030) compared to the non-MPR group. In contrast, the suppressor T cell ratio (TS ratio) was lower (P=0.016) in the MPR group. The difference in peripheral blood lymphocyte subsets between the two groups of patients who underwent neoadjuvant chemoradiotherapy is significant. Conclusion: In peripheral blood, T lymphocyte subsets varied significantly based on the effectiveness of neoadjuvant treatment. Prior to the second cycle of neoadjuvant therapy, a higher CD4/CD8 and TH ratio, coupled with a decreased TS ratio, might suggest enhanced treatment outcomes.

One-step fabricated Zr-supported, CaO-based pellets via graphite-moulding method for regenerable CO2 capture.

Calcium looping (CaL) belongs to a promising high-temperature CO2 capture technology because of adopting cheap and extensive source CaO-based sorbents. However, CaO-based sorbents are prone to occur the issues of sintering and elutriation in the fluidized-bed reactors. To further enhance the practicability, the Zr-supported, CaO-based sorbent pellets were produced using the graphite-moulding method. Different synthesis modes (i.e., sol-gel, hydration-mixing, and wet-mixing) were compared for preparing CaO-based composite slurry before pelletization. Sol-gel is the promising synthesis mode to prepare Zr-supported, CaO-based pellets with outstanding CO2 capture performance due to achieving a more uniform distribution of inert CaZrO3 spacer. Moreover, the Zr-based stabilizer content within sorbent pellets produced by the combined method of sol-gel and graphite-moulding was further studied. The higher content of Zr-based stabilizer promotes the enhancement of cyclic stability and mechanical strength of Zr-supported, CaO-based pellets. After 17 cycles, the sorbent pellets containing 20 wt% of Zr-based stabilizer display a high CaO carbonation conversion of 74.1 %. Moreover, CaO-based pellets with 20 wt% of Zr-based stabilizer possess a higher compression strength of 4.84 ± 1.08 MPa, which is as high as 1.8 times that of the pellets with 5 wt% of Zr-based stabilizer.

Rapid detection of trace formaldehyde in food based on surface-enhanced Raman scattering coupled with assembled purge trap.

It has been remained a challenge to detect trace formaldehyde in complex samples, such as rice flour and duck blood products. In this study, a purge-trap device was designed and used for volatile target detection, which avoided interference adsorptions on enhanced particle surfaces during subsequent surface-enhanced Raman spectroscopy (SERS) analysis. The device produced a low detection limit for formaldehyde of 1 × 10-4 µg/mL in the concentration ranges of 4 × 10-3-4 µg/mL and 1 × 10-4-3 × 10-3 µg/mL. In the process of the detection of duck blood and rice flour, partial least squares regression (PLSR) was adopted for sample analysis. The formaldehyde concentration was calculated and compared to the actual value from the above model with R2 of 0.97, which indicated high accuracy and stability. These results suggested that the proposed method was reliable and suitable for rapid analysis of trace formaldehyde in real products.

Anti-tumour effects of red blood cell membrane-camouflaged black phosphorous quantum dots combined with chemotherapy and anti-inflammatory therapy.

Conventional anti-tumour chemotherapy is facing the challenges of poor specificity, high toxicity and drug resistance. Tumour microenvironment (TME) plays a critical role in tumour development and drug resistance. To address this problem, we constructed a novel anti-tumour nanoparticle platform RBC@BPQDs-DOX/KIR, black phosphorus nanoparticle quantum dots (BPQDs) with one of the chemotherapeutics (doxorubicin, DOX) and an anti-inflammatory traditional Chinese medicine active component (Kirenol, KIR). Red blood cell membrane (RBCm) vesicles were used as the shell to envelop several nanocores. The combination of DOX and KIR may promote therapeutic efficacy, at which the anti-apoptotic effect of the tumour cells was inhibited (by downregulating Bcl-2 and upregulating Bax) and the tumour progression-related inflammatory factors, such as tumour necrosis factor α (TNF-α) and interleukin-6 (IL-6) were downregulated. Furthermore, TME was remodelled and the anti-tumour effect of DOX was magnified. RBCm imparts high biocompatibility and enhanced permeability and retention (EPR) effects to RBC@BPQDs-DOX/KIR, thus enhancing its tumour passively targetability. Overall, the RBCm-camouflaged drug delivery system RBC@BPQDs-DOX/KIR as a promising therapy for targeted chemotherapeutics and anti-inflammatory therapeutics may provide a specific and highly efficient anti-tumour treatment choice.

In situ synthesis of low-cost and large-scale flexible metal nanoparticle-polymer composite films as highly sensitive SERS substrates for surface trace analysis.

Surface-enhanced Raman spectroscopy (SERS) has been one of the most promising analytical tools. Despite many efforts in the design of SERS substrates, it remains a great challenge for creating a general flexible substrate that could in situ detect analytes on diverse objects. Herein, we report our attempt to address this issue by developing a facile and versatile method capable of generating silver/gold nanoparticles in situ on the surface of a cellulose acetate (CA) polymer in a simple, cheap, practical, and capping agent-free way. The as-prepared substrates exhibit excellent sensitivity, which enabled detection of Rhodamine 6G at concentrations as low as 10-12 M. Taking advantage of the excellent flexibility and optical transparency of the CA matrix, the highly SERS-active substrate was applied for in situ identification and detection of pesticide residues on fruits. The results indicated that tetramethylthiuram disulfide (TMTD) and thiabendazole (TBZ) can be clearly identified at concentrations as low as 18.05 ng cm-2 and 15.1 ng cm-2, respectively, which were much lower than the maximum permitted residue doses with respect to food safety.

Fabrication and Sintering Behavior of Er:SrF2 Transparent Ceramics using Chemically Derived Powder.

In this paper, we report the fabrication of high-quality 5 at. % Er3+ ions doped SrF2 transparent ceramics, the potential candidate materials for a mid-infrared laser-gain medium by hot-pressing at 700 °C for 40 h using a chemically-derived powder. The phase structure, densification, and microstructure evolution of the Er:SrF2 ceramics were systematically investigated. In addition, the grain growth kinetic mechanism of Er:SrF2 was clarified. The results showed lattice diffusion to be the grain growth mechanism in the Er:SrF2 transparent ceramic of which highest in-line transmittance reached 92% at 2000 nm, i.e., very close to the theoretical transmittance value of SrF2 single crystal. Furthermore, the emission spectra showed that the strongest emission band was located at 2735 nm. This means that it is possible to achieve a laser output of approximately 2.7 µm in the 5 at. % Er3+ ions doped SrF2 transparent ceramics.

Visual and colorimetric determination of H2O2 and glucose based on citrate-promoted H2O2 sculpturing of silver nanoparticles.

Isotropic silver nanoparticles (iAg NPs) can be easily prepared at low costs, have a low electrochemical potential and high extinction coefficient. An effective colorimetric assay for H2O2 is reported here based on the finding that H2O2 can induce the shape transformation of citrate-capped iAg NPs with the help of citrate. The substantial shape variation affords an apparent surface plasmon resonance (SPR) shift, accompanied by a vivid color change from light yellow to mauve. The color change can be observed visually if the concentration of H2O2 is 2 µM or higher. A good linear relationship was obtained over the concentration range of 0.2-32 µM with a limit of detection of 90 nM. By making use of glucose oxidase, the method is further extended to glucose detection. Glucose at a concentration as low as 10 µM can be well determined with bare eyes. Benefitting from the high selectivity, the detection of glucose in human serum is realized, and the results are in good agreement with those provided by a clinical analyzer. Graphical abstract Schematic presentation of a colorimetric assay for H2O2 and glucose based on citrate-promoted H2O2-mediated shape transformation of the isotropic silver nanoparticles (Ag NPs). The shape variation of isotropic Ag NPs induces a color change from light yellow to mauve.