Europium(III) Functionalized Covalent Organic Framework as Sensitive and Selective Fluorescent Switch for Detection of Uranium.

Uranium poses severe health risks due to its radioactivity and chemical toxicity if released into the environment. Therefore, there is an urgent demand to develop sensing materials in situ monitoring of uranium with high sensitivity and stability. In this work, a fluorescent Eu3+-TFPB-Bpy is synthesized by grafting Eu3+ cation onto TFPB-Bpy covalent organic framework (COF) synthesized through Schiff base condensation of monomers 1,3,5-tris(4-formylphenyl)benzene (TFPB) and 5,5'-diamino-2,2'-bipyridine (Bpy). The fluorescence of Eu3+-TFPB-Bpy is enhanced compared with that of TFPB-Bpy, which is originated from the intramolecular rotations of building blocks limited by the bipyridine units of TFPB-Bpy coordinated with Eu3+. More significantly, Eu3+-TFPB-Bpy is a highly efficient probe for sensing UO22+ in aqueous solution with the luminescence intensity efficiently amplified by complexation of UO22+ with Eu3+. The turn-on sensing capability was derived from the resonance energy transfer occurring from UO22+ to the Eu3+-TFPB-Bpy. The developed probe displayed desirable linear range from 5 nM to 5 µM with good selectivity and rapid response time (2 s) for UO22+ in mining wastewater. This strategy provides a vivid illustration for designing luminescence lanthanide COF hybrid materials with applications in environmental monitoring.

Hydrogen-Bonded Organic Cocrystal-Encapsulated Perovskite Nanocrystals as Coreactant-Free Electrochemiluminescent Luminophore for the Detection of Uranium.

Lead halide perovskite nanocrystals with excellent photophysical properties are promising electrochemiluminescence (ECL) candidates, but their poor stability greatly restricts ECL applications. Herein, hydrogen-bonded cocrystal-encapsulated CsPbBr3 perovskite nanocrystals (PeNCs@NHS-M) were synthesized by using PeNCs as nuclei for inducing the crystallization of melamine (M) and N-hydroxysuccinimide (NHS). The as-synthesized composite exhibits multiplicative ECL efficiencies (up to 24-fold that of PeNCs) without exogenous coreactants and with excellent stability in the aqueous phase. The enhanced stability can be attributed to the well-designed heterostructure of the PeNCs@NHS-M composite, which benefits from both moiety passivation and protection of the peripheral cocrystal matrix. Moreover, the heterostructure with covalent linkage facilitates charge transfer between PeNCs and NHS-M cocrystals, realizing effective ECL emission. Meanwhile, the NHS and M components act as coreactants for PeNCs, shortening the electron-transport distance and resulting in a significant increase in the ECL signal. Furthermore, by taking advantage of the specific binding effect between NHS-M and uranyl (UO22+), an ECL system with both a low detection limit (1 nM) and high selectivity for monitoring UO22+ in mining wastewater is established. The presence of UO22+ disrupted the charge-transfer effect within PeNCs@NHS-M, weakening the ECL signals. This work provides an efficient design strategy for obtaining stable and efficient ECLs from perovskite nanocrystals, offering a new perspective for the discovery and application of perovskite-based ECL systems.

Wallerian Degeneration Assessed by Multi-Modal Magnetic Resonance Imaging of Cervical Spinal Cord Is Associated With Neurological Impairment After Spinal Cord Injury.

While Wallerian degeneration (WD) is a crucial pathological process induced with spinal cord injury (SCI), its underlying mechanisms is still understudied. In this study, we aim to assess structural alterations and clinical significance of WD in the cervical cord following SCI using multi-modal magnetic resonance imaging (MRI), which combines T2*-weighted imaging and diffusion tensor imaging (DTI). T2*-weighted images allow segmentation of anatomical structures and the detection of WD on macrostructural level. DTI, on the other hand, can identify the reduction in neuroaxonal integrity by measuring the diffusion of water molecules on the microstructural level. In this prospective study, 35 SCI patients (19 paraplegic and 16 tetraplegic patients) and 12 healthy controls were recruited between July 2020 and May 2022. The hyperintensity voxels in the dorsal column was manually labeled as WD on T2*-weighted images. The mean cross-sectional area (CSA) and mean DTI indexes of WD at the C2 level were calculated and compared between groups. Correlation analysis was used to determine the associations of the magnitude of WD with lesion characteristics and clinical outcomes. Compared with controls, SCI patients showed evident hyperintensity (35/35) and decreased neuroaxonal integrity (p < 0.05) within the dorsal column at the C2 level. A higher neurological level of injury was associated with a larger mean CSA and reduction in neuroaxonal integrity within WD (p < 0.05). Smaller total and dorsal tissue bridges were related to greater mean CSA and lower fractional anisotropy values in WD (p < 0.05), respectively. Moreover, SCI participants with significantly larger CSAs and significantly lower microstructural integrity had worse sensory outcomes (p < 0.05). This comprehensive evaluation of WD can help us better understand the mechanisms of WD, monitor progression, and assess the effectiveness of therapeutic interventions after SCI.

Hydrogen-Bonded Cocrystals Encapsulating CsPbBr3 Perovskite Nanocrystals with Enhancement of Charge Transport for Photocatalytic Reduction of Uranium.

At present, poor stability and carrier transfer efficiency are the main problems that limit the development of perovskite-based photoelectric technologies. In this work, hydrogen-bonded cocrystal-coated perovskite composite (PeNCs@NHS-M) is easily obtained by inducing rapid crystallization of melamine (M) and N-hydroxysuccinimide (NHS) with PeNCs as the nuclei. The outer NHS-M cocrystal passivates the undercoordinated lead atoms by forming covalent bonds, thereby greatly reducing the trap density while maintaining good structure stability for perovskite nanocrystals. Moreover, benefiting from the interfacial covalent band linkage and long-range ordered structures of cocrystals, the charge transfer efficiency is effectively enhanced and PeNCs@NHS-M displays superior photoelectric performance. Based on the excellent photoelectric performance and abundant active sites of PeNCs@NHS-M, photocatalytic reduction of uranium is realized. PeNCs@NHS-M exhibits U(VI) reduction removal capability of up to 810.1 mg g-1 in the presence of light. The strategy of cocrystals trapping perovskite nanocrystals provides a simple synthesis method for composites and opens up a new idea for simultaneously improving the stability and photovoltaic performance of perovskite.

Rapid Charge Transfer Enabled by Noncovalent Interaction through Guest Insertion in Supercapacitors based on Covalent Organic Frameworks.

Covalent organic frameworks (COFs) have been proposed for electrochemical energy storage, although the poor conductivity resulted from covalent bonds limits their practical performance. Here, we propose to introduce noncovalent bonds in COFs through a molecular insertion strategy for improving the conductivity of the COFs as supercapacitor. The synthesized COFs (MI-COFs) establish equilibriums between covalent bonds and noncovalent bonds, which construct a continuous charge transfer channel to enhance the conductivity. The rapid charge transfer rate enables the COFs to activate the redox sites, bringing about excellent electrochemical energy storage behavior. The results show that the MI-COFs exhibit much better performance in specific capacitance and capacity retention rate than those of most COFs-based supercapacitors. Moreover, through simply altering inserted guests, the mode and strength of noncovalent bond can be adjusted to obtain different energy storage characteristics. The introduction of noncovalent bonds is an effective and flexible way to enhance and regulate the properties of COFs, providing a valuable direction for the development of novel COFs-based energy storage materials.

Secular trends in the incidence of major depressive disorder and dysthymia in China from 1990 to 2019.

BACKGROUND: Depression is increasingly recognized as a worldwide serious, public health concern. A better understanding of depression is important for advancing its management and learning the difference between major depressive disorder (MDD) and dysthymia. Our aim is to conduct a concurrent analysis of the trends of both MDD and dysthymia in China. METHODS: The data on depression from 1990 to 2019 were collected from the Global Burden of Disease Study 2019 (GBD 2019). To determine the average annual percent changes (AAPC) and relative risks (RRs), joinpoint regression and the age-period-cohort models were employed, respectively. RESULTS: The incidence number of MDD and dysthymia continuously increased in China from 1990 to 2019, however, the age-standardized rates (ASR) had a decreasing trend in both men and women. The results from joinpoint regression showed that a declining trend was presented in young people (< 50 years) but an increased trend in the elderly (≥ 50 years) both in men and women, during 1990-2019. Age is the most influential factor for MDD and dysthymia. Age RRs for MDD incidence had an overall increasing trend with age. Period RR in MDD presented a U-shaped pattern, while Cohort RRs presented an inverted U-shaped pattern. On the other hand, RRs in dysthymia for period and cohort effects had no statistical significance, only the age effect presented an inverted U-shaped pattern. CONCLUSIONS: The disparities in trends observed between MDD and dysthymia during the period of 1990-2019 indicated the significance of distinguishing between these two disorders. The age, period and cohort effects all had a greater impact on MDD than on dysthymia, and age effects presented different influential patterns in these two. To alleviate the burden of depressive disorders in China, proactive measures need to be implemented, with particular attention to the elderly population.

The impact of COVID-19 pandemic on reported tuberculosis incidence and mortality in China: An interrupted time series analysis.

Background: The reported number of cases and deaths from common infectious diseases can change during major public health crises. We explored whether the coronavirus disease 2019 (COVID-19) had an impact on tuberculosis (TB) incidence and mortality in China based on routinely reported TB data. Methods: We used TB data used from the monthly national notifiable infectious disease reports in China from January 2015 to January 2023. Based on an interrupted time series (ITS) design, we applied Poisson and negative binomial regression models to assess the changes of reported TB incidence and mortality before and during the COVID-19 pandemic. Results: We found a significant and immediate decrease in the levels of both reported TB incidence (relative risk (RR) = 0.887; 95% confidence interval (CI) = 0.810-0.973) and mortality (RR = 0.448; 95% CI = 0.351-0.572) at the start of COVID-19 outbreak. During the pandemic, the slope of reported incidence decreased significantly (RR = 0.994; 95% CI = 0.989-0.999), while the slope of reported mortality increased sharply (RR = 1.032; 95% CI = 1.022-1.041) owing to an abrupt rise in reported mortality after January 2022. Conclusions: Both TB incidence and mortality decreased immediately at the start of the COVID-19 pandemic. Over a longer period, the COVID-19 pandemic had contributed to a sustained and more significant decrease in reported incidence, and a delayed but sharp increase in reported mortality.

Joint effects of depressive status and body mass index on the risk of incident hypertension in aging population: evidence from a nationwide population-based cohort study.

BACKGROUND: The impact of depressive status (DS) on hypertension incidence is still controversial and has not been studied in Chinese middle-aged and elderly population. This study aimed to explore the relationship between DS and incident hypertension and analyze the joint effects of DS and body mass index (BMI) on hypertension incidence. METHODS: We conducted a prospective cohort study using data from the China Health and Retirement Longitudinal Study (CHARLS), a nationwide population-based study. In 2013, DS was identified using scores from the 10-item Centre for Epidemiological Studies Depression Scale (CES-D-10) among eligible respondents from CHARLS, and hypertension occurrence was observed until 2018. The multiple Cox models were employed to calculate the associations between DS and hypertension incidence. In addition, we also computed the multiplicative interaction (MI) between DS and BMI of incident hypertension and assessed their additive interaction (AI) through relative excess risk due to interaction (RERI), attributable proportion (AP) or synthetic index (S). Positive AI was indicated by RERI > 0, AP > 0 or S > 1. RESULTS: Over the 5-year follow-up, depressive symptoms increased the risk of hypertension incidence by 19% (hazard ratio (HR) = 1.19, 95% confidence interval (CI): (1.01, 1.41)), while depression was associated with a 24% increased risk (HR = 1.24; 95% CI: (1.03, 1.50)). Significant MIs between DS and overweight or obesity were observed and almost all of AI indexes showed positive joint effects on incident hypertension, of which the depression-obesity combination had the largest joint effect (RERI = 4.47, 95%CI: (0.28, 8.66); AP = 0.67, 95%CI: (0.50, 0.85); S = 4.86,95%CI: (2.66, 8.86)). CONCLUSION: DS could lead to hypertension and this impact was amplified when coexisting with higher BMI. It highlighted a need for precise interventions targeting weight management and depression treatment in the aging population to prevent hypertension.

Structural Isomerism of Covalent Organic Frameworks Causing Different Electrochemiluminescence Effects and Its Application for the Detection of Arsenic.

The structural isomerism of the covalent organic framework (COF) has a significant effect on the electrochemiluminescence (ECL) performance. Herein, we report a pair of isomeric COFs, (TFPB-BD(OMe)2-H and TAPB-BD(OMe)2-H), based on the different directions of imine linkages and further conversion of the imine to the quinoline structure. The obtained two isomeric COFs with the same composition and similar structures exhibit dramatic differences in the photoelectrochemical and ECL fields. Indeed, TFPB-BD(OMe)2-H demonstrates robust ECL emission superior to that of TAPB-BD(OMe)2-H. The difference in ECL performance is due to the stronger polar interaction of TFPB-BD(OMe)2-H than that of TAPB-BD(OMe)2-H. The polarity is derived from the uneven charge distribution within the framework and enhances the electron interactions. In addition, the ordered conjugate skeleton provides high-speed charge transport channels for carrier transport. Therefore, the TFPB-BD(OMe)2-H presents a smaller band gap energy and stronger polarization interaction, which are more favorable to charge migration to achieve stronger ECL signals. Furthermore, we describe a convenient ECL sensor for detecting toxic As(V) with an outstanding detection property and ultralow detection limit. This work provides a guiding principle for the design and development of ECL organic luminophores.

Synergistic effect of double Schottky potential well and oxygen vacancy for enhanced plasmonic photocatalytic U(VI) reduction.

Plasmonic photocatalysis is an effective strategy to solve radioactive uranium hazards in wastewater. A plasmonic photocatalyst Bi/Bi2O3-x@COFs was synthesized by in-situ growth of covalent organic frameworks (COFs) on Bi/Bi2O3-x surface for the U(VI) adsorption and plasmonic photoreduction in rare earth tailings wastewater. The presence of oxygen vacancy in Bi/Bi2O3-x and Schottky potential well formed by Bi and Bi2O3-x interface increased the number of free electrons, which induced localized surface plasmon resonance (LSPR) and enhanced the light absorption performance of composites. In addition, oxygen vacancy improved the Fermi level of Bi/Bi2O3-x, leading to another potential well between Bi2O3-x and COFs interface. The electron transport direction was reversed, thus increasing the electron density of COFs layer. COFs was an N-type semiconductor with specific binding U(VI) groups and suitable band structure, which could be used as an active reaction site. Bi/Bi2O3-x@COFs had 1411.5 mg g-1 removal capacity and high separation coefficient for U(VI) due to the synergistic action of photogenerated electrons and hot electrons. Moreover, the removal rate of uranium from rare earth tailings wastewater by regenerated Bi/Bi2O3-x@COFs was over 93.9%. The scheme of introducing LSPR and Schottky potential well provides another way to improve the photocatalytic effect.

Guest Molecular Assembly Strategy in Covalent Organic Frameworks for Electrochemiluminescence Sensing of Uranyl.

The application of covalent organic frameworks (COFs) in electrochemiluminescence (ECL) is promising in environmental monitoring. Developing an emerging design strategy to expand the class of COF-based ECL luminophores is highly desirable. Here, a COF-based host-guest system was constructed through guest molecular assembly to deal with nuclear contamination analysis. The efficient charge transport network was formed by inserting an electron-withdrawing guest tetracyanoquinodimethane (TCNQ) into the open space of the COF host (TP-TBDA; TP = 2,4,6-trihydroxy-1,3,5-benzenetricarbaldehyde and TBDA = 2,5-di(thiophen-2-yl)benzene-1,4-diamine) with an electron-donating property; the construction of the COF-based host-guest system (TP-TBDA@TCNQ) triggered the ECL emission of non-emitting TP-TBDA. Furthermore, the dense active sites in TP-TBDA were utilized to capture the target substance UO22+. The presence of UO22+ broke the charge-transfer effect in TP-TBDA@TCNQ, resulting in the weakening of the ECL signal, thus the established ECL system integrating the low detection limit with high selectivity monitors UO22+. This COF-based host-guest system provides a novel material platform for constructing late-model ECL luminophores and creates an opportunity for the vigorous ECL technology.

D-π-A array structure of Bi4Ti3O12-triazine-aldehyde group benzene skeleton for enhanced photocatalytic uranium (VI) reduction.

Photocatalytic reduction of UVI to UIV can help remove U from the environment and thus reduce the harmful impacts of radiation emitted by uranium isotopes. Herein, we first synthesized Bi4Ti3O12 (B1) particles, then B1 was crosslinked with 6-chloro-1,3,5-triazine-diamine (DCT) to afford B2. Finally, B3 was formed using B2 and 4-formylbenzaldehyde (BA-CHO) to investigate the utility of the D-π-A array structure for photocatalytic UVI removal from rare earth tailings wastewater. B1 lacked adsorption sites and displayed a wide band gap. The grafted triazine moiety in B2 introduced active sites and narrowed the band gap. Notably, B3, a Bi4Ti3O12 (donor)-triazine unit (π-electron bridge)-aldehyde benzene (acceptor) molecule, effectively formed the D-π-A array structure, which formed multiple polarization fields and further narrowed the band gap. Therefore, UVI was more likely to capture electrons at the adsorption site of B3 and be reduced to UIV due to energy level matching effects. UVI removal capacity of B3 under simulated sunlight was 684.9 mg g-1, 2.5 times greater than B1 and 1.8 times greater than B2. B3 was still active after multiple reaction cycles, and UVI removal from tailings wastewater reached 90.8%. Overall, B3 provides an alternative design scheme for enhancing photocatalytic performance.

Influencing factors of death in patients with MDR-TB based on Bayesian Cox regression model. / 基于贝叶斯Coxå›žå½’æ¨¡åž‹åˆ†æžè€å¤šè¯è‚ºç»“æ ¸æ‚£è€ æ­»äº¡çš„å½±å“å› ç´ .

OBJECTIVES: Multidrug-resistant tuberculosis (MDR-TB) has a high mortality and is always one of the major challenges in global TB prevention and control. Analyzing the factors that may impact the adverse outcomes of MDR-TB patients is helpful for improving the systematic management and optimizing the treatment strategies for MDR-TB patients. For follow-up data, the Cox proportional hazards regression model is an important multifactor analysis method. However, the method has significant limitations in its application, such as the fact that it is difficult to deal with the impacts of small sample sizes and other practical issues on the model. Therefore, Bayesian and conventional Cox regression models were both used in this study to analyze the influencing factors of death in MDR-TB patients during the anti-TB therapy, and compare the differences between these 2 methods in their application. METHODS: Data were obtained from 388 MDR-TB patients treated at Lanzhou Pulmonary Hospital from November 1, 2017 to March 31, 2021. Survival analysis was employed to analyze the death of MDR-TB patients during the therapy and its influencing factors. Conventional and Bayesian Cox regression models were established to estimate the hazard ratios (HR) and their 95% confidence interval (95% CI) for the factors affecting the death of MDR-TB patients. The reliability of parameter estimation in these 2 models was assessed by comparing the parameter standard deviation and 95% CI of each variable. The smaller parameter standard deviation and narrower 95% CI range indicated the more reliable parameter estimation. RESULTS: The median survival time (1st quartile, 3rd quartile) of the 388 MDR-TB patients included in the study was 10.18 (4.26, 18.13) months, with the longest survival time of 31.90 months. Among these patients, a total of 12 individuals died of MDR-TB and the mortality was 3.1%. The median survival time (1st quartile, 3rd quartile) for the deceased patients was 4.78(2.63, 6.93) months. The majority of deceased patients, accounting for 50%, experienced death within the first 5 months of anti-TB therapy, with the last mortality case occurring within the 13th month of therapy. The results of the conventional Cox regression model showed that the risk of death in MDR-TB patients with comorbidities was approximately 6.96 times higher than that of patients without complications (HR=6.96, 95% CI 2.00 to 24.24, P=0.002) and patients who received regular follow-up had a decrease in the risk of death by approximately 81% compared to those who did not receive regular follow-up (HR=0.19, 95% CI 0.05 to 0.77, P=0.020). In the results of Bayesian Cox regression model, the iterative history plot and Blue/Green/Red (BGR) plot for each parameter showed the good model convergence, and parameter estimation indicated that the risk of death in patients with a positive first sputum culture was lower than that of patients with a negative first sputum culture (HR=0.33, 95% CI 0.08 to 0.87). Additionally, compared to patients without complications, those with comorbidities had an approximately 6.80-fold increase in the risk of death (HR=7.80, 95% CI 1.90 to 21.91). Patients who received regular follow-up had a 90% reduction in the risk of death compared to those who did not receive regular follow-up (HR=0.10, 95% CI 0.01 to 0.30). The comparison between these 2 models showed that the parameter standard deviations and corresponding 95% CI ranges of other variables in the Bayesian Cox model were significantly smaller than those in the conventional model, except for parameter standard deviations of receiving regular follow-up (Bayesian model was 0.77; conventional model was 0.72) and pulmonary cavities (Bayesian model was 0.73; conventional model was 0.73). CONCLUSIONS: The first year of anti-TB therapy is a high-risk period for mortality in MDR-TB patients. Complications are the main risk factors of death in MDR-TB patients, while patients who received regular follow-up and had positive first sputum culture presented a lower risk of death. For data with a small sample size and low incidence of outcome, the Bayesian Cox regression model provides more reliable parameter estimation than the conventional Cox model.

An ionic vinylene-linked three-dimensional covalent organic framework for selective and efficient trapping of ReO4- or 99TcO4.

The synthesis of ionic olefin linked three-dimensional covalent organic frameworks (3D COFs) is greatly challenging given the hardness of the formation of stable carbon-carbon double bonds (-C = C-). Herein, we report a general strategy for designing porous positively charged sp2 carbon-linked 3D COFs through the Aldol condensation promoted by quaternization. The obtained 3D COFs, namely TFPM-PZI and TAPM-PZI, showed impressive chemical stability. Furthermore, the positively charged frameworks with regular porosity endow 3D ionic COFs with selective capture radioactive ReO4-/TcO4- and great removal efficiency in simulated Hanford waste. This research not only broadens the category of 3D COFs but also promotes the application of COFs as efficient functional materials.

Covalent Organic Frameworks as Advanced Uranyl Electrochemiluminescence Monitoring Platforms.

Electrochemiluminescence (ECL), as an advanced sensing process, can selectively control the generation of excited states by changing the potential. However, most of the existing ECL systems rely on poisonous coreactants to provide radicals for luminescence; although the ECL efficiency was improved, the athematic coreactants will cause unpredictable interference to the accurate analysis of trace targets. Herein, we realized the ECL of nonemitting molecules by performing intramolecular electron transfer in the olefin-linked covalent organic frameworks (COFs), with a high efficiency of 63.7%. Employing internal dissolved oxygen as the coreactant, it is well suitable for the analysis of various complex samples in the environment. Taking nuclear contamination analysis as the goal orientation, we further illustrated a design of a "turn-on" uranyl ion monitoring system integrating fast response, low detection limit, and high selectivity, showing that new ECL-COFs are promising to facilitate environment-related sensing analysis and structure-feature correlation mechanism exploration.

Arousing Electrochemiluminescence Out of Non-Electroluminescent Monomers within Covalent Organic Frameworks.

Covalent organic frameworks (COFs) with stable long-range ordered arrangements are promising materials for organic optoelectronics. However, their electrochemiluminescence (ECL) from non-ECL active monomers has not been realized. Here, we report a design strategy for ECL-emitting COF family. The donors and acceptors co-crystallized and stacked into the highly aligned array of olefin-linked COFs, so that electrons can be transported freely. By this means, a tunable ECL is activated from non-ECL molecules with the maximum efficiency of 32.1% in water with the dissolved oxygen as an inner coreactant, and no additional noxious co-reactant is needed any more. Quantum chemistry calculations further demonstrate that this design reduces the COFs' band gaps and the overlap of electrons and holes in the excited state for better photoelectric properties and stronger ECL signals. This work exploits a basis to envisage the broad application potential of ECL-COFs for various biosensors and light-emitting display.

A general design approach toward covalent organic frameworks for highly efficient electrochemiluminescence.

Electrochemiluminescence (ECL) plays a key role in analysis and sensing because of its high sensitivity and low background. Its wide applications are however limited by a lack of highly tunable ECL luminophores. Here we develop a scalable method to design ECL emitters of covalent organic frameworks (COFs) in aqueous medium by simultaneously restricting the donor and acceptor to the COFs' tight electron configurations and constructing high-speed charge transport networks through olefin linkages. This design allows efficient intramolecular charge transfer for strong ECL, and no exogenous poisonous co-reactants are needed. Olefin-linked donor-acceptor conjugated COFs, systematically synthesized by combining non-ECL active monomers with C2v or C3v symmetry, exhibit strong ECL signals, which can be boosted by increasing the chain length and conjugation of monomers. The present concept demonstrates that the highly efficient COF-based ECL luminophores can be precisely designed, providing a promising direction toward COF-based ECL phosphors.

Preoperative prediction of pathologic grade of HCC on gadobenate dimeglumine-enhanced dynamic MRI.

PURPOSE: To evaluate the value of gadobenate dimeglumine-enhanced MRI in predicting the pathologic grade of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Patients with pathologically proven HCC who underwent preoperative gadobenate dimeglumine-enhanced dynamic MRI were included. Two radiologists blinded to pathology results evaluated images in consensus. Lesions were evaluated quantitatively in terms of ratio of enhancement (RE), and qualitatively based on image features related to tumor aggressiveness. Logistic regression and ROC analyses were used to determine the value of these parameters to predict pathologic grade. RESULTS: In total, 221 patients (194 males, 27 females, aged 52.9 ± 11.7 years) with 49 poorly differentiated HCCs and 172 well/moderately differentiated HCCs were evaluated. Features significantly related to poorer pathologic grade at univariate analysis included lower RE in the early arterial phase (EAP) (p = 0.001), nonsmooth margins (p = 0.001), absence of capsule (p < 0.001), arterial peritumoral hyperenhancement (p < 0.001), higher AFP (p = 0.004), multiple tumors (p = 0.026), and larger tumor size (p = 0.028). At multivariate analysis, lower RE (EAP) (OR = 0.144, p = 0.002), absence of capsule (OR = 0.281, p = 0.004), and arterial peritumoral hyperenhancement (OR = 4.117, p < 0.001) were independent predictive factors for poorer pathologic grade. ROC analysis showed lower RE (EAP) was predictive of poorer pathologic grade (AUC = 0.667). AUC increased to 0.797 when combined with absence of capsule and presence of peritumoral hyperenhancement. CONCLUSIONS: Lower RE (EAP), absence of capsule, and arterial peritumoral hyperenhancement were predictive biomarkers for poorer pathologic grade of HCC on gadobenate dimeglumine-enhanced dynamic MRI. KEY POINTS: • Gadobenate dimeglumine-enhanced dynamic MRI was a useful quantitative biomarker for preoperative prediction of pathologic grade in patients with HCC. • Lower RE in the early arterial phase, absence of capsule, and arterial peritumoral hyperenhancement were potential imaging indicators for preoperative prediction of poorer pathologic grade of HCC on gadobenate dimeglumine-enhanced MRI. • A lower RE in the early arterial phase was effective at predicting poorer pathologic grade of HCCs but prediction is improved when combined with absence of capsule and presence of peritumoral hyperenhancement.

Gold nanoparticles decorated carbon nitride nanosheets as a coreactant regulate the conversion of the dual-potential electrochemiluminescence of Ru(bpy)32+ for Hg2+ detection.

Gold nanoparticles (AuNPs) decorated carbon nitride nanosheets (Au-g-C3N4 NSs) could work as an excellent on-electrode cathodic coreactant for Ru(bpy)32+. Based on the regulation effect of AuNPs and mercury (Hg2+) for the dual-potential electrochemiluminescence (ECL) of Ru(bpy)32+, a simple, sensitive and selective ECL system was created for the ratiometric sensing of Hg2+.