Combining regularization and logistic regression model to validate the Q-matrix for cognitive diagnosis model.

Q-matrix is an important component of most cognitive diagnosis models (CDMs); however, it mainly relies on subject matter experts' judgements in empirical studies, which introduces the possibility of misspecified q-entries. To address this, statistical Q-matrix validation methods have been proposed to aid experts' judgement. A few of these methods, including the multiple logistic regression-based (MLR-B) method and the Hull method, can be applied to general CDMs, but they are either time-consuming or lack accuracy under certain conditions. In this study, we combine the L1 regularization and MLR model to validate the Q-matrix. Specifically, an L1 penalty term is imposed on the log-likelihood of the MLR model to select the necessary attributes for each item. A simulation study with various factors was conducted to examine the performance of the new method against the two existing methods. The results show that the regularized MLR-B method (a) produces the highest Q-matrix recovery rate (QRR) and true positive rate (TPR) for most conditions, especially with a small sample size; (b) yields a slightly higher true negative rate (TNR) than either the MLR-B or the Hull method for most conditions; and (c) requires less computation time than the MLR-B method and similar computation time as the Hull method. A real data set is analysed for illustration purposes.

The effect of refined psychological pain nursing combined with IMB nursing on the pain, sleep and quality of life of patients after cervical cancer surgery.

To explore the effect of refined psychological pain nursing combined with information-motivation-behavioral (IMB) care model on the pain, sleep and quality of life of patients after cervical cancer surgery, so as to provide reference and basis for the nursing of patients after cervical cancer surgery. The clinical data of 798 postoperative cervical cancer patients who were nursing in our hospital from January 2018 to December 2022 were included in this retrospective study and divided into the control group (n = 382) and observation group (n = 416) according to the different care methods. The control group used refined psychological pain nursing, and on this basis, the observation group used IMB nursing to observe and compare the differences in pain, sleep and quality of life between the 2 groups. There was no significant difference in pain between the 2 groups before nursing (P > .05). After nursing, the pain of both groups was significantly improved. The scores of NRS, VAS, and PSEQ of the observation group were significantly better than those of the control group (P < .001). After nursing, the quality of life scores such as emotion, cognition, society, and overall health were significantly higher in the observation group than those of the control group, while physical, fatigue, nausea, vomiting, and pain were significantly lower than those of the control group (P < .05). The negative emotion score of the observation group was significantly lower than that of the control group (P < .001). The residual urine volume and urinary tract infection rate of the observation group were significantly lower than those of the control group (P < .05). The bladder function was significantly better than that of the control group (P < .05). The analgesic effect of refined psychological pain nursing combined with IMB nursing on patients after cervical cancer surgery is better than that of refined psychological pain nursing alone, which can promote pain recovery and further improve the quality of life and sleep quality of patients.

Eggshell translucency in late-phase laying hens and its effect on egg quality and physiological indicators.

Eggshell translucency severely affects external egg quality, and variations in the eggshell or eggshell membrane are considered the structural basis of the trait. Research has shown that 1.85% additional mixed fatty acids in the diet would greatly decrease the occurrence of eggshell translucency. Only a few studies have examined the phenotypic regularity of eggshell translucency with the increasing age of hens. Therefore, two strains, 1139 Rhode Island Red-White (RIR-White) and 836 Dwarf Layer-White (DWL-White), were used, and from each strain, 30 hens each that consecutively laid translucent or opaque eggs at 67 wks of age were selected. Subsequently, eggshell translucency, internal quality and external quality of eggs, and total cholesterol, albumin, calcium binding protein and other physiological indicators related to lipid, lipoprotein, and calcium metabolisms at the 75th, 79th, and 83rd wks of age in the late phase of the laying cycle were determined. Results: (1) In terms of flocks, for both strains, the translucency scores of the translucent groups were significantly higher than those of the opaque groups (P < 0.05); in terms of individuals, 81.1% RIR-White and 82.8% DWL-White hens consecutively laid eggs of the same or similar translucency, indicating the stability of the trait with increasing hen age; (2) In RIR-White, the eggshell strength of the translucent group at 75 weeks was significantly higher than that of the opaque group (P < 0.05); in DWL-White, the eggshell membrane thickness of the translucent group at the 75th and 83rd weeks was significantly lower than that of the opaque group (P < 0.05); (3) Compared to the opaque groups, the translucent groups had lower total cholesterol content in both RIR-White and DWL-White, lower albumin content in DWL-White at the 79th weeks (P < 0.05), and higher calcium-binding protein (CALB1) in RIR-White at the 83rd weeks (P < 0.05). In summary, this study illustrates the stability of eggshell translucency in late-phase laying hens and provides a reference of physiological indicators for exploring the formation of translucent eggs.

Band Modification and Localized Lattice Engineering Leads to High Thermoelectric Performance in Ge and Bi Codoped SnTe-AgBiTe2 Alloys.

SnTe, emerging as an environment-friendly alternative to conventional PbTe thermoelectrics, has drawn significant attention for clean energy conversion. Here, a high peak figure of merit (ZT) of 1.45 at 873 K in Ge/Bi codoped SnTe-AgBiTe2 alloys is reported. It is demonstrated that the existence of Ge, Bi, and Ag facilitate band convergence in SnTe, resulting in remarkable enhancement of Seebeck coefficient and power factor. Simultaneously, localized lattice imperfections including dislocations, point defects, and micro/nanopore structures are caused by incorporation of Ge, Bi, and Ag, which can effectively scatter heat carrying phonons with different wavelengths and contribute to an extremely low κL of 0.61 W m-1  K-1 in Sn0.92 Ge0.04 Bi0.04 Te-10%AgBiTe2 . Such high peak ZT is achieved by decouples electron and phonon transport through band modification and localized lattice engineering, highlighting promising solutions for advancing thermoelectrics.

Theoretical Insights into the Substitution Effect of Phenanthroline Derivatives on Am(III)/Eu(III) Separation.

Separation of trivalent actinides (An(III)) and lanthanides (Ln(III)) poses a huge challenge in the reprocessing of spent nuclear fuel due to their similar chemical properties. N,N'-Diethyl-N,N'-ditolyl-2,9-diamide-1,10-phenanthroline (Et-Tol-DAPhen) is a potential ligand for the extraction of An(III) from Ln(III), while there are still few reports on the effect of its substituent including electron-withdrawing and electron-donating groups on An(III)/Ln(III) separation. Herein, the interaction of Et-Tol-DAPhen ligands modified by the electron-withdrawing groups (CF3, Br) and electron-donating groups (OH) with Am(III)/Eu(III) ions was investigated using scalar relativistic density functional theory (DFT). The analyses of bond order, quantum theory of atoms in molecules (QTAIM), and molecular orbital (MO) indicate that the substitution groups have a slight effect on the electronic structures of the [M(L-X)(NO3)3] (X = CF3, Br, OH) complexes. However, the thermodynamic results suggest that a ligand with the electron-donating group (L-OH) improves the extraction ability of metal ions, and the ligand modified by the electron-withdrawing group (L-Br) has the best Am(III)/Eu(III) selectivity. This work could render new insights into understanding the effect of electron-withdrawing and electron-donating groups in tuning the selectivity of Et-Tol-DAPhen derivatives and pave the way for designing new ligands modified by substituted groups with better extraction ability and An(III)/Ln(III) selectivity.

The effect of seamless nursing combined with Roy adaptive psychological nursing on self-efficacy and bad mood of patients after acute abdomen surgery.

To explore the effect of seamless nursing combined with Roy adaptive psychological nursing on self-efficacy and bad mood of patients after acute abdomen surgery. According to the digital table method, 120 patients with acute abdomen who were treated and nursed in our hospital from June 2019 to June 2021 were selected as prospective research objects, and they were divided into a control group and an observation group with 60 cases each. Among them, the control group carried out seamless nursing, and the observation group carried out Roy adaptive psychological nursing on this basis, and compared the effects of self-efficacy, nursing ability and bad mood of the 2 groups of patients after surgery. Before nursing, the self-efficacy scale, quality of life scores, nursing ability scores, as well as bad mood were not statistically significant between the 2 groups ( P  > .05). After nursing, the self-efficacy scale and nursing ability scores in the observation group were significantly higher than that in the control group ( P  < .05); the social interaction score, anxiety score and depression score were significantly lower than that in the control group ( P  < .001). Seamless nursing combined with Roy adaptive psychological nursing can effectively improve the quality of life of patients after acute abdomen surgery, reduce unhealthy emotions, and improve the nursing ability and self-efficacy of patients after surgery. It has a certain reference for the nursing of patients after acute abdomen surgery.

Theoretical insights into the separation of Am(III)/Eu(III): designing ligands based on a preorganization strategy.

Separation of trivalent actinide (An(III)) and lanthanide (Ln(III)) is a worldwide challenge of nuclear waste treatment. Designing ligands with efficient An(III)/Ln(III) separation performance is still one of the key issues for the disposal of accumulated radioactive waste and the recovery of minor actinides. Recently, N-heterocyclic ligands modified with amide groups have shown excellent An(III)/Ln(III) separation performance. The preorganized structure of the ligands has a great impact on the An(III)/Ln(III) separation performance. We theoretically investigated the extraction behaviors of Am(III) and Eu(III) using phenanthroline (L1 and L2) and bipyridine (L3 and L4) based ligands with a completely or partially preorganized structure. The properties of these ligands and their coordination structures, bonding nature and thermodynamic behaviors with the Am(III) and Eu(III) complexes have been systematically studied in a theoretical fashion. The analyses of the bonding nature suggest that the Am-N bonds possess more covalence than the Eu-N bonds. The thermodynamic results indicate that L2 with a completely preorganized structure has the strongest extraction ability and the best Am(III)/Eu(III) selectivity, while L3 with the most flexible skeleton appears to have the weakest extraction ability and the lowest Am(III)/Eu(III) selectivity. And L1 and L4 have similar performances with regard to Am(III)/Eu(III) selectivity. The results suggest that a certain degree of preorganization of the ligand structure can enhance the extraction ability and Am(III)/Eu(III) selectivity. This work provides valuable information for designing efficient ligands for An(III)/Ln(III) separation by the preorganization strategy.

Reconstruction and Analysis of Thermodynamically Constrained Models Reveal Metabolic Responses of a Deep-Sea Bacterium to Temperature Perturbations.

Microbial acclimation to different temperature conditions can involve broad changes in cell composition and metabolic efficiency. A systems-level view of these metabolic responses in nonmesophilic organisms, however, is currently missing. In this study, thermodynamically constrained genome-scale models were applied to simulate the metabolic responses of a deep-sea psychrophilic bacterium, Shewanella psychrophila WP2, under suboptimal (4°C), optimal (15°C), and supraoptimal (20°C) growth temperatures. The models were calibrated with experimentally determined growth rates of WP2. Gibbs free energy change of reactions (ΔrG'), metabolic fluxes, and metabolite concentrations were predicted using random simulations to characterize temperature-dependent changes in the metabolism. The modeling revealed the highest metabolic efficiency at the optimal temperature, and it suggested distinct patterns of ATP production and consumption that could lead to lower metabolic efficiency under suboptimal or supraoptimal temperatures. The modeling also predicted rearrangement of fluxes through multiple metabolic pathways, including the glycolysis pathway, Entner-Doudoroff pathway, tricarboxylic acid (TCA) cycle, and electron transport system, and these predictions were corroborated through comparisons to WP2 transcriptomes. Furthermore, predictions of metabolite concentrations revealed the potential conservation of reducing equivalents and ATP in the suboptimal temperature, consistent with experimental observations from other psychrophiles. Taken together, the WP2 models provided mechanistic insights into the metabolism of a psychrophile in response to different temperatures. IMPORTANCE Metabolic flexibility is a central component of any organism's ability to survive and adapt to changes in environmental conditions. This study represents the first application of thermodynamically constrained genome-scale models in simulating the metabolic responses of a deep-sea psychrophilic bacterium to various temperatures. The models predicted differences in metabolic efficiency that were attributed to changes in metabolic pathway utilization and metabolite concentration during growth under optimal and nonoptimal temperatures. Experimental growth measurements were used for model calibration, and temperature-dependent transcriptomic changes corroborated the model-predicted rearrangement of metabolic fluxes. Overall, this study highlights the utility of modeling approaches in studying the temperature-driven metabolic responses of an extremophilic organism.

Trajectory of problematic smartphone use among adolescents aged 10-18 years: The roles of childhood family environment and concurrent parent-child relationships.

Background and aims: Adolescence is a period of high incidence of problematic smartphone use. Understanding the developmental trajectory of problematic smartphone use in adolescence and its influencing factors could guide the choice of timing for prevention and intervention. This study fitted the growth trajectory of problematic smartphone use among adolescents and examined its associations with the childhood family environment and concurrent parent-child relationships. Methods: Using a cohort sequential design, we investigated 2,548 Chinese adolescents and their parents three times in three years. Multiple group multiple cohort growth models were used to fit the growth trajectory. Results: The quadratic growth trajectory of problematic smartphone use in adolescents aged 10-18 years showed a clear increasing trend, with a possible decreasing trend in late adolescence or early adulthood. Early life socioeconomic status, childhood family unpredictability, and the concurrent parent-child relationship had unique impacts on the development of problematic smartphone use during adolescence. Discussion and conclusions: Early adolescence is a favorable time for problematic smartphone use prevention and intervention. A supportive family environment should be maintained throughout the different developmental stages of children and adolescents.

Construction of the Largest Metal-Centered Double-Ring Tubular Boron Clusters Based on Actinide Metal Doping.

Metal doping has been considered to be an effective approach to stabilize various boron clusters. In this work, we constructed a series of largest metal-centered double-ring tubular boron clusters An@B24 (An = Th, Pa, Pu, and Am). Extensive global minimum structural searches combined with density functional theory predicted that the global minima of An@B24 (An = Th, Pu, and Am) are double-ring tubular structures. Formation energy analysis indicates that these boron clusters are highly stable, especially for Th@B24 and Pa@B24. Detailed bonding analysis shows that the significant stability of An@B24 is determined by the covalent character of the An-B bonding, which stems from the interactions of An 5f and 6d orbitals and B 2p orbitals. These results show that actinide metal doping is a feasible route to construct stable large metal-centered double-ring tubular boron clusters, offering the possibility to design boron nanomaterials with special physiochemical properties.

Effect of Growth Mindset on Mental Health Two Years Later: The Role of Smartphone Use.

The negative association between the growth mindset and mental health problems suggests that prevention and intervention programs to improve mental health by targeting mindset may have potential clinical value. However, research on the longitudinal effect of mindset on adolescent mental health and its underlying mechanisms is lacking. Using a three-wave longitudinal design, we obtained data from a diverse sample of Chinese adolescents (n = 2543). Longitudinal multiple mediation models were constructed to examine the effects of the growth mindset on levels of anxiety and depression two years later. In addition, the mediating effects of smartphone use for entertainment and problematic smartphone use (PSU) were examined. After controlling for various covariates and the autoregressive effects of mental health problems, the growth mindset had significant negative effects on anxiety (ß = −0.053, p = 0.004) and depression (ß = −0.074, p < 0.001). Smartphone use had a significant mediating role in the effect of mindset on anxiety (ß = −0.016, p < 0.001) and depression (ß = −0.016, p < 0.001). The growth mindset has long-lasting positive effects on adolescent mental health. Smartphone use for entertainment and PSU mediate the effect of mindset on adolescent mental health.

Particular tumor of the pancreas: A case report.

BACKGROUND: Granular cell tumor (GCT) of the pancreas is a rare neurogenic tumor. The first case of pancreatic GCT was described in 1975, and up to now, only 7 cases have been reported. CASE SUMMARY: A 53-year-old male had a pancreatic mass for 1 mo. He was not treated at the local hospital, but referred to Henan Tumor Hospital for surgery. Preoperative imaging revealed a 2.0 cm × 2.5 cm-sized mass located in the body of the pancreas. At the microscopic level, a large number of eosinophilic particles are present in the oval tumor cells. The immunohistochemistry of this tumor cell display CD56 (+), blood vessels CD34 (+), Ki-67 (+) < 10%, and S-100 (+). CONCLUSION: GCT of the pancreas should be recognized as a preoperative differential diagnosis of pancreatic tumors. Surgical resection of the tumor should be attempted; however, GCT of the pancreas has a certain rate of tumor metastasis and recurrence. Therefore, GCT of the pancreas requires regular and long-term follow-up.

Theoretical probing of twenty-coordinate actinide-centered boron molecular drums.

The exploration of metal-doped boron clusters has a great significance in the design of high coordination number (CN) compounds. Actinide-doped boron clusters are probable candidates for achieving high CNs. In this work, we systematically explored a series of actinide metal atom (U, Np, and Pu) doped B20 boron clusters An@B20 (An = U, Np, and Pu) by global minimum structural searches and density functional theory (DFT). Each An@B20 cluster is confirmed to be a twenty-coordinate complex, which is the highest CN obtained in the chemistry of actinide-doped boron clusters so far. The predicted global minima of An@B20 are tubular structures with actinide atoms as centers, which can be considered as boron molecular drums. In An@B20, U@B20 has a relatively high symmetry of C2, while both Np@B20 and Pu@B20 exhibit C1 symmetry. Extensive bonding analysis demonstrates that An@B20 has σ and π delocalized bonding, and the U-B bonds possess a relatively higher covalency than the Np-B and Pu-B bonds, resulting in the higher formation energy of U@B20. Therefore, the covalent character of An-B bonding may be crucial for the formation of these high CN actinide-centered boron clusters. These results deepen our understanding of actinide metal doped boron clusters and provide new clues for developing stable high CN boron-based nanomaterials.

Double-Layer Nitrogen-Rich Two-Dimensional Anionic Uranyl-Organic Framework for Cation Dye Capture and Catalytic Fixation of Carbon Dioxide.

A novel two-dimensional double-layer anionic uranyl-organic framework, U-TBPCA {[NH2(CH3)2][(UO2)(TBPCA)], where H3TBPCA = 4,4',4″-s-triazine-1,3,5-triyltripamino-methylene-cyclohexane-carboxylate}, with abundant active sites and stability was obtained by assembling UO2(NO3)2·6H2O and a triazine tricarboxylate linker, TBPCA3-. Due to the flexibility of the ligand and diverse coordination modes between carboxyl groups and uranyl ions, U-TBPCA exhibits an intriguing topological structure and steric configuration. This double-layer anionic uranyl-organic framework is highly porous and can be used for selective adsorption of cationic dyes. Due to the presence of high-density metal ions and basic -NH- groups, U-TBPCA acts as an effective heterogeneous catalyst for the cycloaddition reaction of carbon dioxide with epoxy compounds. Moreover, the various modes of coordination between the tricarboxylic ligand and uranyl ion were studied by density functional theory calculations, and several simplified models were established to probe the influence of hydrogen bonding between carbon dioxide and U-TBPCA on the ability of U-TBPCA to bind carbon dioxide. This work should aid in improving our understanding of the coordination behavior of uranyl ion as well as the development and utilization of new actinide materials.

Adhesion Enhancement of Micropillar Array by Combining the Adhesive Design from Gecko and Tree Frog.

It has long been demonstrated the gecko-inspired micropillar array with T-shape tips possesses the best adhesion performance of a given material. The further enhancement of the adhesion performances of T-shape micropillars can offer redundant adhesion to compensate for the inevitable improper contacts. Here, the array of T-shape polydimethylsiloxane (PDMS) micropillars is incorporated with gradient dispersed calcium carbonate nanoparticles in the micropillar stalk, termed as T-shape gradient micropillars (TG), possessing the modulus gradient with stiff tip and soft root. The gradient modulus in TG facilitates the contact formation and regulates the stress at the detaching interface, resulting in a 4.6 times adhesion and 2.4 times friction as compared with the pure PDMS T-shape micropillar arrays. The study here provides a new design strategy for the super-strong structured dry adhesives.

Theoretical insights into selective separation of trivalent actinide and lanthanide by ester and amide ligands based on phenanthroline skeleton.

Phenanthroline based ligands have shown potential performance for partitioning trivalent actinides from lanthanides. In this work, we have explored four ester and amide ligands based on the phenanthroline skeleton and elucidated the separation mechanism between Am(iii) and Eu(iii) ions. The molecular geometries and extraction reactions of the metal-ligand complexes were modeled by using scalar-relativistic density functional theory. The results show that the amide based ligands have stronger coordination ability with the metal ions than the corresponding ester based ligands. According to the thermodynamic results, ligands N,N'-diethyl-N,N'-ditolyl-2,9-diamide-1,10-phenanthroline (L2) and N,N'-(1,10-phenanthroline-2,9-diyl)bis(N-ethyl-P-methyl-N-(p-tolyl)phosphinic amide) (L4) appear to have the strongest complexing ability, which is supported by the result of electrostatic potential (ESP) and the M-OL bond orders. Moreover, ligand L2 has excellent selectivity for Am(iii)/Eu(iii) among the four ligands. Additionally, the bonding properties between the metal ions and the ligands reveal that the Am(iii)/Eu(iii) selectivity stems from the Am-N bonds with more covalent character, which is supported by the analysis of the hardness of the ligands and the bond orders. This work provides useful information for understanding the Am(iii)/Eu(iii) selectivity of phenanthroline derived ligands bearing ester and amide groups.

Theoretical Insights into Modification of Nitrogen-Donor Ligands to Improve Performance on Am(III)/Eu(III) Separation.

Nitrogen-donor ligands have been considered to be promising agents for separating trivalent actinides (An(III)) from lanthanides (Ln(III)). Thereinto, how to decorate these ligands for better extraction performance is urgent to design "perfect" separating extractants. In this work, we systematically explored a series of heterocyclic N-donor ligands (L1 = dipyridazino[4,3-c:3',4'-h]acridine, L2 = dipyridazino[3,4-a:4',3'-j]phenazine, L3 = 2,6-di(cinnolin-3-yl)pyridine)), as well as their substituted derivatives, and compared their extraction and complexation ability toward An(III) and Ln(III) ions by using quasi-relativistic density functional theory (DFT). We found that the pyridazine N atoms probably play a notable role in electron donation to metal cations by molecular orbital (MO) and bond order analyses. Besides, the calculated results clearly verified that these N-donor ligands possess higher coordination affinity toward Am(III) over Eu(III). The rigid ligands (L1 and L2) exhibit higher selective abilities for the Am(III)/Eu(III) separation compared with that of the flexible ligand (L3). For each ligand, the 1:2 (metal/ligand) extraction reaction is predicted to be most probable in the separation process. The introduction of an alkyl group on the lateral chain or an electron-donating group on the main chain gives rise to a better extraction performance of the ligands, and the CyMe4 or MeO substituted ligands show higher extraction and separation ability. Simultaneous introduction of CyMe4 and MeO groups can enhance the extraction ability of the ligand to metal ions, but the separating ability depends on the differences of the extraction capacity of An(III) and Ln(III). This work can help to gain a more in-depth understanding the selectivity differences of similar N-donor ligands and provide more theoretical insights into the design of novel extractants for An(III)/Ln(III) separation.

Theoretical Insights into the Selective Extraction of Americium(III) over Europium(III) with Dithioamide-Based Ligands.

Separation of trivalent actinides An(III) from lanthanides Ln(III) is a worldwide challenge owing to their very similar chemical behaviors. It is highly desirable to understand the nature of selectivity for the An(III)/Ln(III) separation with various ligands through theoretical calculations because of their radiotoxicity and experimental difficulties. In this work, we have investigated three dithioamide-based ligands and their extraction behaviors with Am(III) and Eu(III) ions using the scalar-relativistic density functional theory. The results show that the dithioamide-based ligands have stronger electron donating ability than do the corresponding diamide-based ones. All analyses including geometry, Mulliken population, QTAIM (quantum theory of atoms in molecules), and NBO (natural bond orbital) suggest that the Am-S/N bonds possess more covalency compared to the Eu-S/N bonds, and the M-S bonds have more covalent character than the M-N bonds. Thermodynamic results reveal that N2,N9-diethyl-N2,N9-di-p-tolyl-1,10-phenanthroline-2,9-bis(carbothioamide) (L1) has a stronger complexing ability with metal ions owing to its rigid structure and that N6,N6'-diethyl-N6,N6'-di-p-tolyl-[2,2'-bipyridine]-6,6'-bis(carbothioamide) (L2) shows a higher selectivity for the Am(III)/Eu(III) separation. In addition, these dithioamide-based ligands possess Am(III)/Eu(III) selectivity higher than those of the corresponding diamide-based ones, although the former have weaker complexing ability with metal ions, probably due to the greater covalency of the M-S bonds. This theoretical evaluation provides valuable insights into the nature of the selectivity for the Am(III)/Eu(III) separation and information on designing of efficient An(III)/Ln(III) separation with dithioamide-based ligands.

Metal-Carboxyl Helical Chain Secondary Units Supported Ion-Exchangeable Anionic Uranyl-Organic Framework.

As a less explored avenue, actinide-based metal-organic frameworks (MOFs) are worth studying for the particularity of actinide nodes in coordination behaviour and assembly modes. In this work, an azobenzenetetracarboxylate-based anionic MOF supported by uranyl-carboxyl helical chain units was synthesized, incorporating linear uranyl as the metal centre. This kind of helical chain-type building unit is reported for the first time in uranyl-based MOFs. Structural analysis reveals that the formation of helical chain secondary units can be attributed to restricted equatorial coordination of rigid flat azobenzene ligand to uranyl centres. Meanwhile, this newly-synthesized anionic material has been used to remove Eu3+ ions, as a non-radioactive surrogate of Am3+ ion, through an ion-exchange process with [(CH3 )2 NH2 ]+ ions in its open channels, as evidenced by a combination of 1 H NMR spectroscopy, EDS and PXRD.