ECA-TFUnet: A U-shaped CNN-Transformer network with efficient channel attention for organ segmentation in anatomical sectional images of canines.

Automated organ segmentation in anatomical sectional images of canines is crucial for clinical applications and the study of sectional anatomy. The manual delineation of organ boundaries by experts is a time-consuming and laborious task. However, semi-automatic segmentation methods have shown low segmentation accuracy. Deep learning-based CNN models lack the ability to establish long-range dependencies, leading to limited segmentation performance. Although Transformer-based models excel at establishing long-range dependencies, they face a limitation in capturing local detail information. To address these challenges, we propose a novel ECA-TFUnet model for organ segmentation in anatomical sectional images of canines. ECA-TFUnet model is a U-shaped CNN-Transformer network with Efficient Channel Attention, which fully combines the strengths of the Unet network and Transformer block. Specifically, The U-Net network is excellent at capturing detailed local information. The Transformer block is equipped in the first skip connection layer of the Unet network to effectively learn the global dependencies of different regions, which improves the representation ability of the model. Additionally, the Efficient Channel Attention Block is introduced to the Unet network to focus on more important channel information, further improving the robustness of the model. Furthermore, the mixed loss strategy is incorporated to alleviate the problem of class imbalance. Experimental results showed that the ECA-TFUnet model yielded 92.63% IoU, outperforming 11 state-of-the-art methods. To comprehensively evaluate the model performance, we also conducted experiments on a public dataset, which achieved 87.93% IoU, still superior to 11 state-of-the-art methods. Finally, we explored the use of a transfer learning strategy to provide good initialization parameters for the ECA-TFUnet model. We demonstrated that the ECA-TFUnet model exhibits superior segmentation performance on anatomical sectional images of canines, which has the potential for application in medical clinical diagnosis.

Mannose-doped metal-organic frameworks induce tumor cell pyroptosis via the PERK pathway.

BACKGROUND: The implementation of pyroptosis exhibits significant potential as a tactic to enhance tumor immune microenvironments. Previous applications of pyroptosis inducers have encountered various limitations, such as the development of drug resistance, manifestation of toxic side effects, and a deficiency in targeting capabilities. As a result, there is a growing demand for tumor therapeutic molecules that can overcome these obstacles. Therefore, the objective of this study is to develop a multifunctional nanospheres that addresses these challenges by enabling high-precision targeting of tumor cells and inducing effective pyroptosis. RESULTS: We prepared a mannose-modified MOF called mannose-doped Fe3O4@NH2-MIL-100 (M-FNM). M-FNM could enter CAL27 cells through MR-mediated endocytosis, which caused in a significant increase in the level of intracellular ROS. This increase subsequently triggered ER stress and activated the PERK-eIF2α-ATF4-CHOP signaling pathway. CHOP then mediated the downstream cascade of Caspase-1, inducing pyroptosis. In in vivo experiments, M-FNM demonstrated excellent targeting ability and exhibited anti-tumor effects. Additionally, M-FNM reshaped the immune microenvironment by promoting the infiltration of anti-tumor immune cells, primarily T lymphocytes. CONCLUSIONS: M-FNM significantly decreased tumor growth. This novel approach to induce pyroptosis in tumor cells using M-FNM may offer new avenues for the development of effective immunotherapies against cancer.

Three Robust Isoreticular Metal-Organic Frameworks with High-Performance Selective CO2 Capture and Separation.

Based on the hard-soft acid base (HSAB) theory, three robust isoreticular metal-organic frameworks (MOFs) with nia topology were successfully synthesized by solvothermal reaction {[In3O(BHB)(H2O)3]NO3·3DMA (JLU-MOF110(In)), [Fe3O(BHB)(H2O)3]NO3 (JLU-MOF110(Fe)), and [Fe2NiO(BHB)(H2O)3] (JLU-MOF110(FeNi)) (DMA = N,N-dimethylacetamide, H6BHB = 4,4″-benzene-1,3,5-triyl-hexabenzoic acid)}. Both JLU-MOF110(In) and JLU-MOF110(Fe) are cationic frameworks, and their BET surface areas are 301 and 446 m2/g, respectively. By modification of the components of metal clusters, JLU-MOF110(FeNi) features a neutral framework, and the BET surface area is increased up to 808 m2/g. All three MOF materials exhibit high chemical and thermal stability. JLU-MOF110(In) remains stable for 24 h at pH values ranging from 1 to 11, while JLU-MOF110(Fe) and JLU-MOF110(FeNi) persist to be stable for 24 h at pH from 1 to 12. JLU-MOF110(In) exhibits thermal stability up to 350 °C, whereas JLU-MOF110(Fe) and JLU-MOF(FeNi) can be stable up to 300 °C. Thanks to the microporous cage-based structure and abundant open metal sites, JLU-MOF110(In), JLU-MOF110(Fe), and JLU-MOF110(FeNi) have excellent CO2 capture capacity (28.0, 51.5, and 99.6 cm3/g, respectively, under 298 K and 1 bar). Interestingly, the ideal adsorption solution theory results show that all three MOFs exhibit high separation selectivity toward CO2 over N2 (35.2, 43.2, and 43.2 for CO2/N2 = 0.15/0.85) and CO2 over CH4 (14.4, 11.5, and 10.1 for CO2/CH4 = 0.5/0.5) at 298 K and 1 bar. Thus, all three MOFs are potential candidates for CO2 capture and separation. Among them, JLU-MOF110(FeNi) displays the best separation potential, as revealed by dynamic column breakthrough experiments.

An ethynyl-modified interpenetrated metal-organic framework for highly efficient selective gas adsorption.

An ethynyl-modified interpenetrated MOF material with lvt topology, [Cu2(BTEB)(NMF)2]·NMF·8H2O (compound 1, H4BTEB = 4,4',4'',4'''-(benzene-1,2,4,5-tetrayltetrakis(ethyne-2,1-diyl))tetrabenzoic acid, NMF = N-Methylformamide), was successfully synthesized by using an alkynyl-functionalized H4BTEB organic ligand under solvothermal conditions. Structural analysis shows that compound 1, consisting of a tetradentate carboxylic acid ligand and classical [Cu2(CO2)4] paddle-wheel structure building units, has a rare 4-connected lvt topology with dual interpenetrating structure, which can improve the framework stability, as well as the gas adsorption capacity and selectivity due to the restricted pore channel. According to the study of gas adsorption performance, compound 1 with a larger surface area, boasts a superior adsorption capacity for small gas molecules. Also, ideal adsorption solution theory (IAST) computational simulation shows that compound 1 has good gas adsorption selectivity for C3H8/CH4, indicating its potential application in gas separation.

Exploring the Effect of Different Secondary Building Units as Lewis Acid Sites in MOF Materials for the CO2 Cycloaddition Reaction.

In order to explore the catalytic effect of different Lewis acid sites (LASs) in the CO2 cycloaddition reaction, different secondary building units and N-rich organic ligand 4,4',4″-s-triazine-1,3,5-triyltri-p-aminobenzoate were assembled to construct six reported MOF materials: [Cu3(tatab)2(H2O)3]·8DMF·9H2O (1), [Cu3(tatab)2(H2O)3]·7.5H2O (2), [Zn4O(tatab)2]·3H2O·17DMF (3), [In3O(tatab)2(H2O)3](NO3)·15DMA (4), [Zr6O4(OH)7(tatab)(Htatab)3(H2O)3]·xGuest (5), and [Zr6O4(OH)4(tatab)4(H2O)3]·xGuest (6) (DMF = N,N-dimethylformamide, and DMA = N,N-dimethylacetamide). Large pore sizes of compound 2 enhance the concentration of substrates, and the multi-active sites inside its framework synergistically promote the process of the CO2 cycloaddition reaction. Such advantages endow compound 2 with the best catalytic performance among the six compounds and surpass many of the reported MOF-based catalysts. Meanwhile, the comparison of the catalytic efficiency indicated that Cu-paddlewheel and Zn4O display better catalytic performances than In3O and Zr6 cluster. The experiments investigate the catalytic effects of LAS types and prove that it is feasible to improve CO2 fixation property by introducing multi-active sites into MOFs.

Construction of highly-stable covalent organic framework with combined enol-imine and keto-enamine linkages.

A novel covalent organic framework (COF) (Tp-BI-COF) with combined ketimine-type enol-imine and keto-enamine linkages was prepared through a cascade of ketimine condensation followed by aldimine condensation and characterized by XRD, solid state 13C NMR, IR, TGA and BET. Tp-BI-COF showed high stability toward acid, organic solvent, and boiling water. The 2D COF exhibited photochromic properties after being irradiated with a xenon lamp. The stable COF, with aligned one-dimensional nanochannels, provided nitrogen sites on pore walls, which confine and stabilize the H3PO4 in the channel via hydrogen-bonding interactions. After loading with H3PO4, the material showed excellent anhydrous proton conductivity.

Identification of the MMP family as therapeutic targets and prognostic biomarkers in the microenvironment of head and neck squamous cell carcinoma.

BACKGROUND: Head and Neck Squamous Cell Carcinoma is a malignant tumor with high morbidity and mortality. The MMP family plays an important role in tumor invasion and metastasis. However, the mechanistic value of the MMP family as a therapeutic target and prognostic biomarker in HNSC has not been fully elucidated. METHODS: Oncomine, UALCAN, GEPIA, cBioportal, GeneMANIA, STRING, DAVID6.8, TRRUST, TIMER and Linkedomics were used for analysis. RESULTS: The mRNA expression levels of MMP1, MMP3, ILF3, MMP7, MMP9, MMP10, MMP11, MMP12, MMP13 and MMP16 were higher in HNSC than those in normal tissues, while the mRNA expression level of MMP15 was reduced. The relative expression levels of MMP1 and MMP14 were the highest in HNSC tissues. A significant correlation was found between the expression of MMP3, MMP11, MMP25 and the pathological stage of HNSC patients. There was no significant associations between all the MMP family members expression levels and DFS. Increased mRNA levels of MMP1, MMP8 and MMP25 were significantly associated with OS. In addition, we investigated the genetic changes of the MMP family in HNSC and found that all the MMP family members had genetic changes, most of which were amplification and depth loss. In the analysis of neighbor gene network and protein interaction, we found that the MMP family interacted with 25 neighboring genes, except for ILF3, MMP19, MMP20, MMP21, MMP23B, MMP27 and MMP28, other MMP proteins interacted with each other. Functional enrichment analysis showed that the MMP family could be present in the extracellular matrix, regulate peptidase activity, and participate in the catabolism of collagen. Meanwhile, we identified the transcription factor targets and kinase targets of the MMP family and found that ATM and ATR were the two most common kinase targets in the MMP family. We also found a significant correlation between the MMP family expression and immune cell infiltration. Cox proportional risk model analysis showed that macrophages, MMP14, MMP16, and MMP19 were significantly associated with clinical outcomes in HNSC patients. CONCLUSION: The MMP family might serve as therapeutic target and prognostic biomarker in HNSC.

Gold Nanoparticles Immobilized in Porous Aromatic Frameworks with Abundant Metal Anchoring Sites as Heterogeneous Nanocatalysts.

Porous aromatic frameworks (PAFs) with rich metal coordination sites are highly effective support materials for gold nanoparticles (AuNPs), which would not only prevent AuNPs agglomeration but also facilitate mass transfer during the catalytic process. In this work, PAF-160, -161, and -162 bearing diphosphine units are synthesized via the Friedel-Crafts alkylation reaction to act as efficient platforms for AuNPs immobilization. These PAFs possess high surface areas (up to 655 m2 g-1) together with excellent stabilities, and the different linkage lengths between P centers allow more scattered and accessible sites for gold coordination. In the resultant Au-PAFs, AuNPs with uniform sizes are stabilized dispersedly. The catalytic performances of these Au-PAFs are monitored by the reduction of 4-nitrophenol (4-NP), and all materials exhibit excellent catalytic activities on the reduction of 4-NP, especially Au-PAF-162 with the apparent rate constant (kapp) up to 0.019 s-1. Additionally, the reductions of various nitroarenes with different functional groups are explored and all Au-PAFs can convert most nitroaromatic derivatives to the corresponding arylamines with high conversions of 99%, in which the reaction mechanism is also proposed. Furthermore, a continuous catalytic device with Au-PAF-160 catalyst is explored, and Au-PAF-160 can convert 1-chloro-4-nitrobenzene, 2,6-dichoronitrobenzene and 1-chloro-2,4-dinitrobenzene into the corresponding amines in sequence in the continuous flow catalytic experiments. This work has enriched the variety of porous materials for noble metal immobilization and promotes their applications in heterogeneous catalysis.

Hydrogen-Bond-Connected 2D Zn-LMOF with Fluorescent Sensing for Inorganic Pollutants and Nitro Aromatic Explosives in the Aqueous Phase.

Herein, a novel luminescent Zn-LMOF, JLU-MOF109 ([Zn(PBBA)(H2O)]·3DMF·2H2O, PBBA = 4,4'-(2,6-pyrazinediyl)bis[benzoic acid], DMF = N,N-dimethylformamide), was successfully synthesized under solvothermal conditions. Zinc ions are connected by PBBA ligands to form two-dimensional (2D) layers, and the layers are further propped up through hydrogen-bonding interactions. JLU-MOF109 exhibits good sensitivity to inorganic pollutants, Fe3+ and Cr2O72-, as well as nitro aromatic explosives, 2,4,6-trinitrophenol and 2,4-dinitrophenol. JLU-MOF109 exhibits high Ksv (at 104 M-1 level) and low limit of detection values (∼10-6 mol/L) for the abovementioned hazardous pollutants, which is better than a majority of previously reported MOF-based fluorescent sensors. With good stability in the aqueous phase, JLU-MOF109 can serve as a promising chemical sensor for pollutant detection in wastewater.

Fine-Tuned Ultra-Microporous Metal-Organic Framework in Mixed-Matrix Membrane: Pore-Tailoring Optimization for C2 H2 /C2 H4 Separation.

Effective separation of ethyne from ethyne/ethylene (C2 H2 /C2 H4 ) mixtures is a challenging and crucial industrial process. Herein, an ultra-microporous metal-organic framework (MOF) platform, Cd(dicarboxylate)2 (ditriazole), with triangular channels is proposed for high-efficiency separation of C2 H2 from C2 H4 . The targeted structures are constructed via a mixed-ligand strategy by selecting different-sized ligands, allowing for tunable pore sizes and volumes. The pore properties can be further optimized by additional modification via pore environment tailoring. This concept leads to the successful synthesis of three ultra-microporous Cd-MOFs (JLU-MOF87-89). As intended, C2 H2 uptake and C2 H2 /C2 H4 selectivity gradually increase with progressively optimizing the pore structure by adjusting ligand length and substituents. JLU-MOF89, functionalized with methyl groups, features the most optimal pore chemistry and shows selective recognition of C2 H2 over C2 H4 , owing to the framework-C2 H2 host-guest interactions. Furthermore, JLU-MOFs are fabricated into mixed-matrix membranes for C2 H2 /C2 H4 separation. C2 H2 permeability and C2 H2 /C2 H4 permselectivity are substantially enhanced by ≥400% and ≥200%, respectively, after hybridization of JLU-MOF88 and JLU-MOF89 with a polyimide polymer (6FDA-ODA). These membranes can work efficiently and are stable under different conditions, demonstrating their potential in actual ethyne separation.

Unique Fluorescence Turn-On and Turn-Off-On Responses to Acids by a Carbazole-Based Metal-Organic Framework and Theoretical Studies.

Distinct from predominately known fluorescence quenching (turn-off) detection, turn-on response to hazardous substances by luminescent metal-organic frameworks (LMOFs) could greatly avoid signal loss and susceptibility to environmental stimulus. However, such detection rarely occurs and lacks theoretical elucidations. Here, we present the first example of unique turn-on and unprecedented turn-off-on responses to a variety of acids by a stable 12-connected hexanuclear Y(III)-cluster-based LMOF material─JLU-MOF111, featuring the nondefault pcu topology. Benefiting from the "pocket" structures formed by the carbazole-containing ligands, JLU-MOF111 can sense multiple inorganic and organic acids via different degrees of fluorescence turn-on behaviors. Particularly, turn-on sensing of HNO3, HCl, HBr, and TFA is hypersensitive with LODs as low as the ppb level. Theoretical calculations confirm weak interactions in acid-ligand complexes, which lead to constrained rotations of benzene moieties of the ligands when the complexes decay from excited states. These account for the turn-on response through reduced nonradiative energy consumption that competes with emissive decay. The turn-off-on response to 4-NBA and 3,5-DNBA involves an excited-state electron transfer process that dominates the turn-off stage and prohibited nonradiative decay that competes with the intrinsic emission of the ligand and dominates the turn-on stage. This work has a guiding significance for the full-scale understanding of turn-on and turn-off-on sensing performance in LMOF materials and beyond.

Two Robust Isoreticular Metal-Organic Frameworks with Different Interpenetration Degrees Exhibiting Disparate Breathing Behaviors.

Herein, two robust isoreticular metal-organic frameworks (MOFs), ([Bi(CPTTA)]·[Me2NH2]·2DMF) (JLU-MOF120, H4CPTTA = 5'-(4-carboxyphenyl)-[1,1':3',1″-terphenyl]-3,4″,5-tricarboxylic acid, DMF = N, N- dimethylformamide) and ([In(CPTTA)]·[MeNH3]·2.5H2O·1.5NMF) (JLU-MOF121, NMF = N- methylformamide), with different interpenetration degrees were successfully constructed. According to the hard-soft acid-base (HSAB) theory, high-valent metal ions and carboxylate-based ligands were selected and formed twofold interpenetrated structures with saturated coordinated mononuclear second building units ([M(COO)4], M = Bi, In). Owing to the features of the frameworks, JLU-MOF120 and JLU-MOF121 exhibited excellent stability, which could retain their integrity in water for at least 14 days and aqueous solutions with a pH range of 3-11 for at least 24 h. According to the structural regulation strategy, by changing the torsion angles of the ligand, the degrees of interpenetration for JLU-MOF120 and JLU-MOF121 were different, leading to various gate-opening pressures in CO2 at 195 K. Furthermore, JLU-MOF120 exhibits the scarce potential of C2H2/CO2 separation among Bi-MOF materials at 298 K under 101 kPa, JLU-MOF121 shows high CO2/CH4 selectivity under ambient conditions (11.7 for gas mixtures of 50 and 50% and 16.1 for gas mixtures of 5 and 95%). Moreover, owing to the flexibility of the structure, JLU-MOF121 possesses disparate breathing behaviors for C2H2 and C2H6 at 273 and 298 K, with the differences in uptakes among C2 hydrocarbons resulting in the potentiality of C2H4 purification. Overall, such HSAB theory and the structural regulation strategy could provide a valid method for constructing stable and flexible structures for the application in gas separation.

Designing Multicomponent Metal-Organic Frameworks with Hierarchical Structure-Mimicking Distribution for High CO2 Capture Performance.

By utilizing a mixed-ligand strategy, a novel multicomponent Cu-metal-organic framework (MOF) (JLU-MOF107) has been successfully synthesized. JLU-MOF107 has an unusual hierarchical structure-mimicking distribution structure. The triangular 4,4',4″-benzene-1,3,5-triyl-tribenzoate (BTB) ligand and the binuclear Cu cluster form a threefold interpenetration layer, while the linear ligand 1,4-phenylene-4,4'-bis(1,2,4-triazole) (p-tr2ph) and tetranuclear Cu cluster form a noninterpenetration pillared-layer structure. Then, the two types of layers are connected by tetranuclear Cu clusters to construct the final sandwichlike framework. JLU-MOF107 exhibits good water and humidity stability. Due to the presence of various active sites and pores, JLU-MOF107 shows an outstanding performance for CO2 capture (171.0 cm3 g-1 at 273 K). Density functional theory (DFT)-based calculations further prove the interactions between CO2 molecules and multiple active sites. The innovative synthesis of this multicomponent structure offers a new perspective on making hierarchical porous materials and multifunctional MOFs.

A Stable Y(III)-Based Amide-Functionalized Metal-Organic Framework for Propane/Methane Separation and Knoevenagel Condensation.

Here, a Y(III)-based metal-organic framework, JLU-MOF112 {[Y3(µ3-O)2(µ3-OH)(H2O)2(BTCTBA)2]·2[(CH3)2NH2]·5DMF·C6H5Cl·4H2O}, has been successfully synthesized under solvothermal conditions. JLU-MOF112 was constructed with amide-functionalized tricarboxylate ligands and Y(III)-based infinite chains, where the Y3 repeating units are arranged in a trans order. The overall framework could be viewed as a novel (3,5)-connected net with two types of channels along the [100] and [010] directions. JLU-MOF112 possesses a large BET surface area (1553 m2 g-1), a permanent pore volume (0.67 cm3 g-1), and outstanding thermal and chemical stability, which give JLU-MOF112 potential for the purification of natural gas, especially the equimolar separation of C3H8/CH4 with a high selectivity of 176. In addition, benefiting from the amide functional groups as Brønsted basic sites and the exposure of open metal sites as Lewis acid sites after activation, JLU-MOF112 can serve as a high-efficiency heterogeneous catalyst for Knoevenagel condensation by the reactions of malononitrile with benzaldehyde (yield of 98%, turnover number of 392, and turnover frequency of 3.27 min-1) and diverse aldehyde compounds. A rational mechanism was put forward that the Knoevenagel condensation was catalyzed by the synergistic effect of the Lewis acid sites and Brønsted basic sites, engendering the polarization of the carbonyl groups and the deprotonation of the methylene groups for nucleophilic attack.

Highly efficient Cr(VI) removal from industrial electroplating wastewater over Bi2S3 nanostructures prepared by dual sulfur-precursors: Insights on the promotion effect of sulfate ions.

In this work, different Bi2S3 nanostructures were prepared from various single and dual sulfide precursors via a solvothermal method. It was found that Bi2S3 nanostructures prepared from dual sulfur precursors of L-cysteine and ammonium sulfide exhibited highest Cr(VI) removal ability with maximum Cr(VI) removal capacity of 148.95 mg/g in Cr(VI) solution (pH = 2). More importantly, the removal capacity strikingly increased to 223.33 and 240.25 mg/g in two kinds of actual industrial electroplating wastewater. By analyzing the components of actual electroplating wastewater and the results of control experiments in the absence and presence of different ions in Cr(VI) solution, it was found that SO42- played a critical role in the Cr(VI) removal over Bi2S3. The addition of SO42- could promote the conversion of Cr(VI) to Cr(III) on the surface of Bi2S3, thus leading to the enhanced Cr(VI) removal ability in actual electroplating wastewater. The Bi2S3 maintained its original Cr(VI) removal ability after four cycles in the electroplating wastewater, indicating the moderate reuse ability of the sample. This work not only demonstrated an highly efficient nanomaterials for the Cr(VI) removal in industrial electroplating wastewater, but also provided an insight on the influence of the components in wastewater on Cr(VI) removal.

Fabrication of Metal Nanoparticle Composites by Slow Chemical Reduction of Metal-Organic Frameworks.

Constructing metal nanoparticle (MNP) composites from metal-organic framework (MOF) precursors has attracted extensive attention as the MOF precursors provide an excellent porous matrix for the generation of MNP composites, which enables the direct fabrication of well-dispersed MNP composites. In this work, a novel strategy is proposed to fabricate MNP composites by slow chemical reduction (SCR) of MOF precursors at room temperature. The reduction process is skillfully slowed via using ethanol as the solvent, and the formation of MNP composites is then realized by the SCR process. Briefly, BH4- slowly diffuses into an MOF precursor and in situ reduces metal ions to well-dispersed nanoscale MNP composites. Meanwhile, this SCR process breaks the coordination bonds from MOF precursors, leading to the generation of porous structures for the resulting composites. Interestingly, the composites inherit the morphology of MOF precursors well. Besides, this SCR strategy allows construction of MNP composites from different types of MOF precursors. The resulting Cu@HK-3 composites possess well-dispersed nanoscale Cu NPs and a porous architecture, which exhibit superior catalytic performance and stability in the Ullmann coupling reaction. This strategy provides a feasible, convenient, and energy-saving route to prepare MNP composites from MOF precursors with customizable morphology and well-dispersed MNPs.

Contiguous layer based metal-organic framework with conjugated π-electron ligand for high iodine capture.

Herein, a novel 3-dimensional (3D) Cu(II) metal-organic framework (MOF), [Cu3(µ2-O)2(p-tr2Ph)2(HCOO)][NO3]·3DMF·3H2O (compound 1), which is constructed by directly interlocking regionalized hollow two-dimensional (2D) layers, has been conceived and solvothermally synthesized. Such a distinctive regionalized pore system effectively maintains the uniformity of the pore structure, isolates the counterions and bridging ligands in the partition layer, and endows compound 1 with high porosity. In consequence, compound 1 exhibits excellent adsorption ability of iodine in cyclohexane. The removal efficiency in cyclohexane solution (0.01 mol L-1) can reach up to 80% in 8 min, and the absorption ability towards iodine can reach about 1.15 g g-1. Moreover, iodine can also be controllably released in ethanol. The release rate was up to 4 × 10-5 mol L-1 min-1. Furthermore, compound 1 also showed prominent recyclability due to the high stability, and the maximum sorption amount could be retained after 3 cycles. This study paves a new way towards opening up MOFs' potential application in capturing radioactive iodine to protect the environment.

A dual-emissive europium-based metal-organic framework for selective and sensitive detection of Fe3+ and Fe2.

A dual-emissive optical material as a ratiometric fluorescent probe has been demonstrated to be remarkably superior in precise and quantitative analyses. Herein, a novel dual-emissive fluorescent probe Eu-BDC-OH was designed and successfully synthesized using Eu3+ and 2-hydroxyterephthalic acid (H2BDC-OH) at room temperature. Eu-BDC-OH has a three-dimensional interpenetrating network structure with a large number of exposed hydroxyl functional groups, providing abundant active sites for molecular recognition. In particular, the as-obtained Eu-BDC-OH serves as a unique fluorescent probe, and the double emission peaks of both the ligand and Eu3+ are completely quenched by Fe3+. However, it is worth noting that the dual emissions of Eu-BDC-OH enable the ratiometric detection of Fe2+, which leads to an increase in ligand emission and a decrease in Eu3+ emission, accompanied by a distinct red to blue color transition. The relative fluorescence intensity ratio (I618 nm/I433 nm) decreased linearly with increasing Fe2+ concentration in the 0-50 µM range with a superior detection limit of 0.32 µM. In this work, a fluorescent probe based on a MOF was developed for the recognition of Fe2+ and Fe3+, providing a promising strategy for the synthesis of novel dual-emission materials by integrating suitable luminescent ligands with lanthanide metal ions.

Structural Regulation and Light Hydrocarbon Adsorption/Separation of Three Zirconium-Organic Frameworks Based on Different V-Shaped Ligands.

On the basis of different V-shaped ligands, three zirconium-organic frameworks (JLU-Liu45, Zr-SDBA, and Zr-OBBA) have been successfully constructed. By regulating spatial configuration and functional groups of organic ligands, these as-synthesized Zr-MOFs (MOF = metal-organic framework) display distinct structures and different light hydrocarbon adsorption/separation capabilities. JLU-Liu45, with a double-walled interpenetrated 3D primitive cubic (pcu) framework, exhibits good gas-adsorption capacity but not prominent selective separation ability. Through regulating sizes and torsion angles of the organic ligands, Zr-SDBA possesses a 2D square lattice (sql) network, while Zr-OBBA displays a non-interpenetrated 3D pcu framework. Furthermore, by regulating functional groups on the ligands, Zr-SDBA shows prominent C2H2 uptake (101.2 cm3·g-1) and the best C2H2/CH4 selectivity (230.5, 1:1) among the three Zr-MOFs, and Zr-OBBA shows a significant C3H8/CH4 selectivity (105.6, 1:1). This work demonstrates the feasibility of structural regulation for MOF materials in the light hydrocarbon adsorption/separation field.

Preparation of Superhydrophobic Metal-Organic Framework/Polymer Composites as Stable and Efficient Catalysts.

Metal-organic frameworks (MOFs), as a chemical platform, combined with multifunctional polymers are of interest in catalytic applications, which can not only inherit the outstanding properties of the two components but also lead to unique synergistic effects. Nonetheless, most MOFs possess varying degrees of water instability, which limits their real application. Herein, we fabricated highly hydrophobic MOF/polymer composites via a universal post-synthetic polymerization strategy as efficient catalysts. Polyaniline (PANI) was first hybridized with MOFs by vapor deposition polymerization, and then, hydrophobic molecules were grafted to the PANI by a covalent linking process, thereby forming a superhydrophobic MOF/PANI hybrid material (MOF/PANI-shp). The resultant MOF/PANI-shp not only obtains superior moisture/water resistance without significantly disturbing the original features but also exhibits a novel catalytic selectivity in styrene oxidation because of the accessible sites and synergistic effects. Such a synthetic strategy for the MOF/polymer catalyst opens a new avenue for the design of a unique catalyst with outstanding catalytic efficiency, selectivity, and stability.