Host Recovery from Respiratory Viral Infection.

Emerging and re-emerging respiratory viral infections pose a tremendous threat to human society, as exemplified by the ongoing COVID-19 pandemic. Upon viral invasion of the respiratory tract, the host initiates coordinated innate and adaptive immune responses to defend against the virus and to promote repair of the damaged tissue. However, dysregulated host immunity can also cause acute morbidity, hamper lung regeneration, and/or lead to chronic tissue sequelae. Here, we review our current knowledge of the immune mechanisms regulating antiviral protection, host pathogenesis, inflammation resolution, and lung regeneration following respiratory viral infections, mainly using influenza virus and SARS-CoV-2 infections as examples. We hope that this review sheds light on future research directions to elucidate the cellular and molecular cross talk regulating host recovery and to pave the way to the development of pro-repair therapeutics to augment lung regeneration following viral injury.

An aberrant immune-epithelial progenitor niche drives viral lung sequelae.

The long-term physiological consequences of respiratory viral infections, particularly in the aftermath of the COVID-19 pandemic-termed post-acute sequelae of SARS-CoV-2 (PASC)-are rapidly evolving into a major public health concern1-3. While the cellular and molecular aetiologies of these sequelae are poorly defined, increasing evidence implicates abnormal immune responses3-6 and/or impaired organ recovery7-9 after infection. However, the precise mechanisms that link these processes in the context of PASC remain unclear. Here, with insights from three cohorts of patients with respiratory PASC, we established a mouse model of post-viral lung disease and identified an aberrant immune-epithelial progenitor niche unique to fibroproliferation in respiratory PASC. Using spatial transcriptomics and imaging, we found a central role for lung-resident CD8+ T cell-macrophage interactions in impairing alveolar regeneration and driving fibrotic sequelae after acute viral pneumonia. Specifically, IFNγ and TNF derived from CD8+ T cells stimulated local macrophages to chronically release IL-1ß, resulting in the long-term maintenance of dysplastic epithelial progenitors and lung fibrosis. Notably, therapeutic neutralization of IFNγ + TNF or IL-1ß markedly improved alveolar regeneration and pulmonary function. In contrast to other approaches, which require early intervention10, we highlight therapeutic strategies to rescue fibrotic disease after the resolution of acute disease, addressing a current unmet need in the clinical management of PASC and post-viral disease.

De Novo Green Fluorescent Protein Chromophore-Based Probes for Capturing Latent Fingerprints Using a Portable System.

Rapid visualization of latent fingerprints, preferably at their point of origin, is essential for effective crime scene evaluation. Here, we present a new class of green fluorescent protein chromophore-based fluorescent dyes (LFP-Yellow and LFP-Red) that can be used for real-time visualization of LFPs within 10 s. Compared with traditional chemical reagents for LFPs, these fluorescent dyes are completely water-soluble, exhibit low cytotoxicity, and are harmless to users. Level 1-3 details of the LFPs could be clearly revealed through "off-on" fluorescence signal readout. Additionally, the fluorescent dyes were constructed based on an imidazolinone core and so do not contain pyridine groups or metal ions, which ensures that the DNA is not contaminated during extraction and identification after the LFPs are treated with the dyes. Combined with our as-developed portable system for capturing LFPs, LFP-Yellow and LFP-Red enabled the rapid capture of LFPs. Therefore, these green fluorescent protein chromophore-based probes provide an approach for the rapid identification of individuals who were present at a crime scene.

Factors associated with the intrinsic capacity in older adults: A scoping review.

INTRODUCTION: In 2015, the term 'intrinsic capacity' (IC) was proposed by the World Health Organisation to promote healthy aging. However, the factors associated with IC are still discrepant and uncertain. AIM: We aim to synthesise the factors connected with IC. METHODS: This scoping review followed the five-stage framework of Arksey and O'Malley and was reported using PRISMA-ScR guidelines. RESULTS: In all, 29 articles were included. IC of older adults is associated with demographic characteristics, socioeconomic factors, disease conditions, behavioural factors, and biomarkers. Age, sex, marital status, occupation status, education, income/wealth, chronic diseases, hypertension, diabetes, disability, smoking status, alcohol consumption, and physical activity were emerged as important factors related to the IC of older adults. CONCLUSIONS: This review shows that IC is related to multiple factors. Understanding these factors can provide the healthcare personnel with the theoretical basis for intervening and managing IC in older adults. RELEVANCE TO CLINICAL PRACTICE: The influencing factors identified in the review help to guide older adults to maintain their own intrinsic capacity, thereby promoting their health and well-being. The modifiable factors also provide evidence for healthcare personnel to develop targeted intervention strategies to delay IC decline. NO PATIENT OR PUBLIC CONTRIBUTION: As this is a scoping review, no patient or public contributions are required.

The prevalence and characteristics of alexithymia in stroke patients: a systematic review and meta-analysis.

BACKGROUND: Previous studies have indicated the potential occurrence of alexithymia among stroke patients, yet the prevalence of alexithymia in this population remains disparate across different investigations without a synthesized overview. AIM: To systematically evaluate the prevalence and characteristics of alexithymia in stroke patients. METHODS: A systematic review and meta-analysis was conducted following the PRISMA guidelines. PubMed, Embase, Web of Science, The Cochrane Library, CINAHL, China Knowledge Resource Integrated Database (CNKI), Wanfang Database, Chinese Biomedical Database, and Weipu Database (VIP) were searched from inception to December 31,2022, two independent researchers extracted data and evaluated article quality. RESULTS: Seventeen studies were included, reporting on the prevalence of alexithymia or Toronto Alexithymia Scale-20 (TAS-20) scores among stroke patients. The pooled prevalence was found to be 35.0% (95%CI= 23.0-47.0%; I2 =97.5%), and the total scores (TS) of TAS-20 was 59.90 (95% CI=56.34-63.47; I2 =100.0%). Subgroup analysis revealed significant variation in TAS-20 scores across different geographical regions. Specifically, the total TAS-20 score in Chinese stroke patients (62.95, 95%CI=58.75-67.14; I2=100%) was higher compared to non-Chinese stroke patients (52.58, 95%CI=49.12-56.04; I2 = 99.0%). CONCLUSIONS: The prevalence of alexithymia is high among stroke patients, with TAS-20 scores surpassing those observed in patients with certain other medical conditions. This underscores the importance of addressing alexithymia in stroke patients promptly through assessment and intervention to mitigate negative emotional consequences and enhance overall quality of life. Future research could explore the influence of demographic factors such as age and sex on alexithymia in stroke patients, enabling a more comprehensive understanding of alexithymia.

Repeatability of radiomics studies in colorectal cancer: a systematic review.

BACKGROUND: Recently, radiomics has been widely used in colorectal cancer, but many variable factors affect the repeatability of radiomics research. This review aims to analyze the repeatability of radiomics studies in colorectal cancer and to evaluate the current status of radiomics in the field of colorectal cancer. METHODS: The included studies in this review by searching from the PubMed and Embase databases. Then each study in our review was evaluated using the Radiomics Quality Score (RQS). We analyzed the factors that may affect the repeatability in the radiomics workflow and discussed the repeatability of the included studies. RESULTS: A total of 188 studies was included in this review, of which only two (2/188, 1.06%) studies controlled the influence of individual factors. In addition, the median score of RQS was 11 (out of 36), range-1 to 27. CONCLUSIONS: The RQS score was moderately low, and most studies did not consider the repeatability of radiomics features, especially in terms of Intra-individual, scanners, and scanning parameters. To improve the generalization of the radiomics model, it is necessary to further control the variable factors of repeatability.

A novel electrochemical sensing platform based on double-active-center polyimide covalent organic frameworks for sensitive analysis of levofloxacin.

The development of a simple and sensitive electrochemical sensing platform for levofloxacin (LVF) analysis is of great significance to human health. In this work, a covalent organic framework (TP-COF) was in situ grown on the surface of Sn-MoC nanospheres with nanoflower-like morphology through a one-pot method to obtain the TP-COF@Sn-MoC composite. The prepared composite was used to modify a glassy carbon electrode (GCE) to realize the sensitive detection of levofloxacin. TP-COF was formed by polycondensation of 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TAPT) and pyromellitic dianhydride (PMDA), in which C = O and C = N groups served as double active centers for the recognition and electrocatalytic oxidation of the target molecule. Meanwhile, the introduction of Sn-MoC improved the conductivity of the electrode. The TP-COF@Sn-MoC composite produced a strong synergistic effect and showed a high electrocatalytic ability toward levofloxacin oxidation. The linear range of LVF was 0.6-1000 µM and the limit of detection (LOD) was 0.029 µM (S/N = 3). In addition, the sensor has been successfully applied for the analysis of LVF in human urine and blood serum samples with acceptable recovery rates, demonstrating that the sensor was promising in practical applications.

Host RAB11FIP5 protein inhibits the release of Kaposi's sarcoma-associated herpesvirus particles by promoting lysosomal degradation of ORF45.

Open reading frame (ORF) 45 is an outer tegument protein of Kaposi's sarcoma-associated herpesvirus (KSHV). Genetic analysis of an ORF45-null mutant revealed that ORF45 plays a key role in the events leading to the release of KSHV particles. ORF45 associates with lipid rafts (LRs), which is responsible for the colocalization of viral particles with the trans-Golgi network and facilitates their release. In this study, we identified a host protein, RAB11 family interacting protein 5 (RAB11FIP5), that interacts with ORF45 in vitro and in vivo. RAB11FIP5 encodes a RAB11 effector protein that regulates endosomal trafficking. Overexpression of RAB11FIP5 in KSHV-infected cells decreased the expression level of ORF45 and inhibited the release of KSHV particles, as reflected by the significant reduction in the number of extracellular virions. In contrast, silencing endogenous RAB11FIP5 increased ORF45 expression and promoted the release of KSHV particles. We further showed that RAB11FIP5 mediates lysosomal degradation of ORF45, which impairs its ability to target LRs in the Golgi apparatus and inhibits ORF45-mediated colocalization of viral particles with the trans-Golgi network. Collectively, our results suggest that RAB11FIP5 enhances lysosome-dependent degradation of ORF45, which inhibits the release of KSHV particles, and have potential implications for virology and antiviral design.

Morphological Regulation of Printed Low-Temperature Conductive Ink.

The unbalanced evaporation of solvents in low-temperature sintered inks for printed electronics leads to a series of problems in the actual printing process, including printed pattern distortion, surface cracking, and the coffee ring effect, which has become a serious obstacle to this technique. Here, we present a comprehensive investigation of the influence of the solvent composition, environmental, and sintering conditions on the complicated pattern formation process of reactive silver inks. The results first showed that only inks with a certain wettability of solvents could form well-defined patterns. Then, the solvent composition and ambient humidity can be adjusted to balance the nonequilibrium evaporative flow within the liquid and thus to obtain a flat liquid film. Combined with the rapid UV sintering process, the particle size, porosity, and roughness could be controlled to produce dense and homogeneous silver films. Finally, we successfully printed silver electrodes with a smooth and dense surface (Rqs ∼ 21 nm in 0.8 × 0.8 mm2 area and less than 1% porosity) under an optimized relative humidity (RH) of 50-60% at room temperature with the solvent composition of IPA (isopropanol)/2,3-BD (2,3-butanediol) = 8:2. In addition, we also demonstrated high-performance Pr-IZO (praseodymium-doped indium-zinc oxide) thin film transistors (TFTs) with a mobility (µsat) of 2.14 cm2/V/s and Ion/Ioff ratio of over 107 using source-drain electrodes printed under optimized conditions.

NCOA2 promotes lytic reactivation of Kaposi's sarcoma-associated herpesvirus by enhancing the expression of the master switch protein RTA.

Reactivation of Kaposi's sarcoma-associated herpesvirus (KSHV) is important for persistent infection in the host as well as viral oncogenesis. The replication and transcription activator (RTA) encoded by KSHV ORF50 plays a central role in the switch from viral latency to lytic replication. Given that RTA is a transcriptional activator and RTA expression is sufficient to activate complete lytic replication, RTA must possess an elaborate mechanism for regulating its protein abundance. Previous studies have demonstrated that RTA could be degraded through the ubiquitin-proteasome pathway. A protein abundance regulatory signal (PARS), which consists of PARS I and PARS II, at the C-terminal region of RTA modulates its protein abundance. In the present study, we identified a host protein named Nuclear receptor coactivator 2 (NCOA2), which can interact with RTA in vitro and in vivo. We further showed that NCOA2 binds to the PARS II domain of RTA. We demonstrated that NCOA2 enhances RTA stability and prevents the proteasome-mediated degradation of RTA by competing with MDM2, an E3 ubiquitin ligase of RTA that interacts with the PARS II domain. Moreover, overexpression of NCOA2 in KSHV-infected cells significantly enhanced the expression level of RTA, which promotes the expression of RTA downstream viral lytic genes and lytic replication. In contrast, silencing of endogenous NCOA2 downregulated the expression of viral lytic genes and impaired viral lytic replication. Interestingly, we also found that RTA upregulates the expression of NCOA2 during lytic reactivation. Taken together, our data support the conclusion that NCOA2 is a novel RTA-binding protein that promotes RTA-driven lytic reactivation by increasing the stability of RTA, and the RTA-NCOA2 positive feedback regulatory loop plays an important role in KSHV reactivation.

Enhanced Single-Chain Magnet Behavior via Anisotropic Exchange in a Cyano-Bridged MoIII -MnII Chain.

Anisotropic magnetic exchange is of great value for the design of high performance molecular nanomagnets. In the present work, enhanced single-chain magnet (SCM) behavior is observed for a MoIII -MnII chain that exhibits anisotropic magnetic exchange. Self-assembly of the pentagonal bipyramidal [Mo(CN)7 ]4- anion and the MnII unit with a tridentate ligand results in a neutral double zigzag 2,4-ribbon structure which exhibits SCM behavior with a high relaxation barrier of 178(4) K. Open magnetic hysteresis loops are observed below 5.2 K, with a coercive field of 1.5 T at 2 K. Interestingly, this SCM can be considered to be a result of a step-wise process based on our previously reported Mn2 Mo single-molecule magnets (SMMs).

Reversible On-Off Switching of the Hysteretic Spin Crossover in a Cobalt(II) Complex via Crystal to Crystal Transformation.

Reversible controlling and switching of magnetic bistability remains relatively difficult. Here, reversible on-off switching of a hysteretic spin transition in a CoII complex via a single-crystal to single-crystal (SC-SC) transformation during dehydration and rehydration was reported. Upon dehydration, a switching from a basically low spin state to an abrupt and hysteretic spin crossover (SCO) with broad hysteresis loops was achieved. Hysteretic and anisotropic crystal lattice expansion or contraction in the spin transition temperature range was also observed in the dehydrated complex. The magneto-structural relationship in this system was established on the basis of detailed structure analyses on both the hydrated and dehydrated examples over a wide range of temperatures. The elimination of guest internal pressure, the tuning of the supramolecular interactions, and the strong electron-lattice coupling should be responsible for the hysteretic SCO in the dehydrated complex.

Heterometallic MIILnIII (M = Co/Zn; Ln = Dy/Y) Complexes with Pentagonal Bipyramidal 3d Centers: Syntheses, Structures, and Magnetic Properties.

We herein reported the syntheses, structures, and magnetic properties of three dinuclear heterometallic MIILnIII complexes, namely, [MIILnIII(H2L)(CH3OH)2(NO3)2](NO3)·S (M = Co, Ln = Dy, S = MeOH (1CoDy); M = Zn, Ln = Dy, S = MeOH (2ZnDy); M = Co, Ln = Y, S = MeNO2 (3CoY), H4L = 2,6-diacetylpyridine bis[2-(semicarbazono) propionylhydrazone]. Synthesized from the predesigned multidentate ligand H4L, which has two different coordination pockets (smaller N3O2 and larger N2O4 pockets) suitable for either a 3d or a 4f metal center, all these complexes have very similar structures, where the MII centers possess a pentagonal bipyramidal (PBP) geometry and the LnIII sites have a tetradecahedron geometry. Magnetic measurements on these compounds revealed the existence of weak ferromagnetic coupling between the Co2+ and Dy3+ centers and the field-induced slow magnetic relaxation of all three complexes. Furthermore, theoretical calculation on all these complexes indicates that although the change of the diamagnetic Zn2+ ion to the paramagnetic Co2+ ion only slightly modifies the local magnetic anisotropy of the Dy3+ ion, the weak Co-Dy magnetic interaction decreases the energy barrier. These compounds are the first systematic results of a heterometallic 3d-4f single-molecule magnet containing predesigned PBP 3d metal ions.

Reversible On-Off Switching of a Single-Molecule Magnet via a Crystal-to-Crystal Chemical Transformation.

Dynamic molecular crystals are of high interest due to their potential applications. Herein we report the reversible on-off switching of single-molecule magnet (SMM) behavior in a [Mo(CN)7]4- based molecular compound. Upon dehydration and rehydration, the trinuclear Mn2Mo molecule [Mn(L)(H2O)]2[Mo(CN)7]·2H2O (1) undergoes reversible crystal-to-crystal transformation to a hexanuclear Mn4Mo2 compound [Mn(L)(H2O)]2[Mn(L)]2[Mo(CN)7]2 (2). This structural transformation involves the breaking and reforming of coordination bonds which leads to significant changes in the color and magnetic properties. Compound 1 is an SMM with an energy barrier of 44.9 cm-1, whereas 2 behaves as a simple paramagnet despite its higher ground state spin value. The distortion of the pentagonal bipyramidal geometry of [Mo(CN)7]4- in 2 disrupts the anisotropic exchange interactions that lead to SMM behavior in 1.

Slow Magnetic Relaxation in One-Dimensional Azido-Bridged CoII Complexes.

Crystal structures and magnetic properties of three one-dimensional (1D) azido-bridged cobalt(II) chains with different amide ligands (L), [Co2(N3)4(DMF)3] (1), [Co4(N3)8(DEF)5] (2), and [Co2(N3)4(DIPF)2] (3) (DMF = N,N-dimethylformamide, DEF = N,N-diethylformamide, and DIPF = N,N-diisopropylformamide), are reported to investigate the influence of L on their structures and magnetic properties. Single-crystal X-ray crystallographic analysis revealed that, although 1-3 all consist of cobalt chains bridged by end-on (EO) azides, the coordination geometry of the CoII ions and the repeating units of the 1D structures are quite different. As the size of L increases, the ratio of L to CoII decreases from 6:4 in 1 to 5:4 and 4:4 in 2 and 3, respectively. In 1, two [CoN5O1] and two [CoN4O2] distorted octahedra form the {[CoN5O1][CoN4O2]2[CoN5O1]} tetramers (denoted as Co4A), which are linked to each other by sharing the N-N edge to form the chain. Similarly, the chain structure of 3 is constructed from a similar tetramer unit {[CoN5][CoN4O2]2[CoN5]} (denoted as Co4B), where half of the CoII centers are in the [CoN5] trigonal bipyramid because of the larger steric effect of the DIPF ligand, while, for compound 2 of the medium-sized amide, it has the transition structure between those of 1 and 3. The chain is composed of two different repeating units: Co4A unit similar to that in 1 and Co4B unit similar to that in 3. Because of their similar structures, compounds 1-3 exhibit analogical magnetic properties. Direct-current magnetic measurements demonstrated that all compounds show intrachain ferromagnetic coupling through the EO azides and interchain anti-ferromagnetic interactions. Alternating-current data revealed the slow magnetic relaxation in the anti-ferromagnetic ordered phases. While compound 1 exhibits spin glass behavior, compounds 2 and 3 behave as the single-chain magnets. This difference might come from the interference of the anti-ferromagnetic ordering on the magnetic dynamic of the magnetic chain.

Three-Dimensional FeII-[MoIII(CN)7]4- Magnets with Ordering below 65 K and Distinct Topologies Induced by Cation Identity.

Two cyanide-bridged compounds based on the FeII cation and the anisotropic [MoIII(CN)7]4- anion, namely, {Fe2(H2O)5[Mo(CN)7]·5H2O}n (1) and {[NH2(CH3)2]2Fe5(H2O)10[Mo(CN)7]3·8H2O}n (2), have been prepared. Single crystal X-ray analyses revealed that their structures exhibit different three-dimensional topologies as a result of the addition of [NH2(CH3)2]+ during the synthesis of 2. For both 1 and 2, the geometry of the [Mo(CN)7]4- unit is a slightly distorted capped trigonal prism; all FeII centers are hexacoordinate and adopt a distorted octahedral configuration. Compound 1 is a three-nodal 3,4,7-connected net with the point symbol of {4.62}{45.6}{46.612.83}, while compound 2 is a five-nodal 4,4,4,6,7-connected net with the point symbol of {44.62}{45.6}4{46.67.82}{49.611.8}2. Magnetic studies revealed that both compounds exhibit magnetic ordering below 65 K. Apart from the plethora of MnII-[Mo(CN)7]4- compounds documented in the literature, these two FeII-[Mo(CN)7]4- compounds are the only other [Mo(CN)7]4- extended structures to be characterized by single crystal structures to date.

A One-Dimensional Magnet Based on [Mo(III)(CN)7](4.).

Self-assembly of the [Mo(III)(CN)7](4-) anion and the Mn(II) unit with a macrocyclic ligand results in the first example of a one-dimensional (1D) chain compound based on the heptacyanomolybdate, [Mn(LN5C10)]2[Mo(CN)7]·2H2O (LN5C10 = 1,4,7,10,13-pentaazacyclopentadecane). Because of the existence of the interchain magnetic coupling, long-rang magnetic ordering was observed in this compound.

New insights into hydrosilylation of unsaturated carbon-heteroatom (C═O, C═N) bonds by rhenium(V)-dioxo complexes.

The hydrosilylation of unsaturated carbon-heteroatom (C═O, C═N) bonds catalyzed by high-valent rhenium(V)-dioxo complex ReO2I(PPh3)2 (1) were studied computationally to determine the underlying mechanism. Our calculations revealed that the ionic outer-sphere pathway in which the organic substrate attacks the Si center in an η(1)-silane rhenium adduct to prompt the heterolytic cleavage of the Si-H bond is the most energetically favorable process for rhenium(V)-dioxo complex 1 catalyzed hydrosilylation of imines. The activation energy of the turnover-limiting step was calculated to be 22.8 kcal/mol with phenylmethanimine. This value is energetically more favorable than the [2 + 2] addition pathway by as much as 10.0 kcal/mol. Moreover, the ionic outer-sphere pathway competes with the [2 + 2] addition mechanism for rhenium(V)-dioxo complex 1 catalyzing the hydrosilylation of carbonyl compounds. Furthermore, the electron-donating group on the organic substrates would induce a better activity favoring the ionic outer-sphere mechanistic pathway. These findings highlight the unique features of high-valent transition-metal complexes as Lewis acids in activating the Si-H bond and catalyzing the reduction reactions.

A Machine Learning Model Based on Counterfactual Theory for Treatment Decision of Hepatocellular Carcinoma Patients.

Purpose: To predict the efficacy of patients treated with hepatectomy and transarterial chemoembolization (TACE) based on machine learning models using clinical and radiomics features. Patients and Methods: Patients with HCC whose first treatment was hepatectomy or TACE from June 2016 to July 2021 were collected in the retrospective cohort study. To ensure a causal effect of treatment effect and treatment modality, perfectly matched patients were obtained according to the principle of propensity score matching and used as an independent test cohort. Inverse probability of treatment weighting was used to control bias for unmatched patients, and the weighted results were used as the training cohort. Clinical characteristics were selected by univariate and multivariate analysis of cox proportional hazards regression, and radiomics features were selected using correlation analysis and random survival forest. The machine learning models (Deathhepatectomy and DeathTACE) were constructed to predict the probability of patient death after treatment (hepatectomy and TACE) by combining clinical and radiomics features, and an optimal treatment regimen was recommended. In addition, a prognostic model was constructed to predict the survival time of all patients. Results: A total of 418 patients with HCC who received either hepatectomy (n=267, mean age, 58 years ± 11 [standard deviation]; 228 men) or TACE (n=151, mean age, 59 years ± 13 [standard deviation]; 127 men) were recruited. After constructing the machine learning models Deathhepatectomy and DeathTACE, patients were divided into the hepatectomy-preferred and TACE-preferred groups. In the hepatectomy-preferred group, hepatectomy had a significantly prolonged survival time than TACE (training cohort: P < 0.001; testing cohort: P < 0.001), and vise versa for the TACE-preferred group. In addition, the prognostic model yielded high predictive capability for overall survival. Conclusion: The machine learning models could predict the outcomes difference between hepatectomy and TACE, and prognostic models could predict the overall survival for HCC patients.

Imine-linked covalent organic framework with high crystallinity for constructing sensitive purine bases electrochemical sensor.

In this work, a covalent organic framework (TADM-COF) with high crystallinity and large specific surface area (2597 m2 g-1) has been successfully synthesized using 1,3,5-(4-aminophenyl) benzene (TAPB) and 2,5-dimethoxy-p-phenyldiformaldehyde (DMTP). The COF was grown in situ on oxide particles to form core-shell nanocomposites (SiO2@TADM COF, Fe3O4@TADM COF and Co3O4@TADM COF) to realize its function as a shell material. Among them, the Co3O4@TADM COF with the highest electrochemical response to purine bases was further cross-linked with multi-walled carbon nanotubes (MWCNT) to construct a novel electrochemical sensor (Co3O4@TADM COF/MWCNT/GCE) for detection of purine bases. In this nanocomposite, Co3O4 possesses rich catalytic active sites, MWCNT ensures superior electrical conductivity and COF provides a stable environment for electrocatalytic reactions as the shell. At the same time, regular pore structure of the COFs also offers smooth channels for the transfer of analytes to the catalytic site. The synergistic effect among the three components showed remarkable sensing performance for the simultaneous detection of guanine (G) and adenine (A) with a wide linear range of 0.6-180 µM and low limits of detection (LODs) of 0.020 µM for G and 0.024 µM for A (S/N = 3), respectively. The developed sensor platform was also successfully applied in the detection of purine bases in thermally denatured herring DNA extract. The work provided a general strategy for amplifying signal of COF and its composite in the electrochemical sensing.