Computational design and preparation of water-compatible noncovalent imprinted microspheres.

Herein, 2,4-dichlorophenoxyacetic acid (2,4-D) was used as a model template in a rational design strategy to produce water-compatible noncovalent imprinted microspheres. The proposed approach involved computational modelling for screening functional monomers and a simple method for preparing monodisperse and highly cross-linked microspheres. The fabricated non-imprinted polymer (NIP) and 2,4-d-imprinted polymer (2,4-d-MIP) were characterised, and their adsorption capabilities in an aqueous environment were evaluated. Results reveal that the pseudo-second-order kinetics model was appropriate for representing the adsorption of 2,4-D on NIP and 2,4-d-MIP, with R2 values of 0.97 and 0.99, respectively. The amount of 2,4-D adsorbed on 2,4-d-MIP (97.75 mg g-1) was considerably higher than those of phenoxyacetic acid (35.77 mg g-1), chlorogenic acid (9.72 mg g-1), spiramycin (1.56 mg g-1) and tylosin (1.67 mg g-1). Furthermore, it exhibited strong resistance to protein adsorption in an aqueous medium. These findings confirmed the feasibility of the proposed approach, providing a reference for the development of water-compatible noncovalent imprinted polymers.

[Critical Review on Heavy Metal Contamination in Urban Soil and Surface Dust].

With the rapid urbanization and industrialization, heavy metal contamination in urban soil and surface dust has received particular attention due to its negative effects on the eco-environment and human health. Contamination and spatio-temporal characteristics, contamination sources, and source apportionment methods, as well as the ecological and health risks of heavy metals in urban soil and surface dust were reviewed. The knowledge gaps in current research and prospects of future works were proposed. Four key points were presented, including improving the research on the interaction mechanism of heavy metals in urban soil and surface dust under complex conditions, enriching verification methods to improve the source apportionment reliability of anthropogenic metals by receptor models, strengthening the research on chemical forms of heavy metals from different sources and their short-term accumulation processes in surface dust, and raising the credibility of ecological and health risk forecast of heavy metals by integrating the improved exposure parameters and chemical forms.

Structure elucidation and antiviral activity of a cold water-extracted mannogalactofucan Ts1-1A from Trametes sanguinea against human cytomegalovirus in vitro.

In this study, we purified a partially acetylated heteropolysaccharide (Ts1-1A) from the fruit bodies of Trametes sanguinea Lloyd through cold water extraction and serial chromatographic separation. The purified polysaccharide Ts1-1A (12.8 kDa) was characterized as a branched mannogalactofucan with a backbone of alternately connected 1,3-linked α-Fucp and 1,6-linked α-Galp, which was partially substituted by non-reducing end units of ß-Manp at O-2 and O-3 positions of 1,6-linked α-Galp. Ts1-1A showed pronounced anti-human cytomegalovirus activity at the concentration of 200 and 500 µg/mL in systematical assessments including morphological changes, western blotting, qPCR, indirect immunofluorescence and tissue culture infective dose assays. Moreover, Ts1-1A exerted its antiviral activity at two distinct stages of viral proliferation manifesting as significantly inhibiting viral protein (IE1/2 and p52) expression and reducing viral gene (UL123, UL44 and UL32) replication in the HCMV-infected WI-38 cells. At viral attachment stage, Ts1-1A interacted with HCMV and prevented HCMV from attaching to its host cells. While at early phase of viral replication stage, Ts1-1A suppressed HCMV replication by downregulating NQO1 and HO-1 proteins related to oxidative stress as an antioxidant. To sum up, Ts1-1A is a promising anti-HCMV agent which could be developed for HCMV infection prevention and therapy.

Trends in Mortality Related to Hepatitis B and C from 1990 to 2019 in the Western Pacific Region.

Background/Aims: : This study aimed to analyze the trends in mortality attributed to hepatitis B and C around the Western Pacific region from 1990 to 2019. Methods: : We used data from the Global Burden of Disease Study for a systematic analysis. The deaths related to hepatitis B and C were analyzed by age, sex, year, risk factors, geographical location, and Socio-demographic Index (SDI). Results: : From 1990 to 2019, the annual total deaths from hepatitis B decreased from 0.266 to 0.210 million and those from hepatitis C increased from 0.119 to 0.142 million in the Western Pacific region. The age-standardized mortality rate (ASMR) of hepatitis B and C decreased by 63.5% and 48.0%, respectively. The declines in the ASMR related to hepatitis B and C were only detected in 12 and two Western Pacific countries, respectively. As the major risk factors, the contribution of alcohol use to hepatitis B deaths was 52% and drug use to hepatitis C was 80%. In males and females, the ASMR attributed to hepatitis B decreased by 61% and 71%, respectively, and the ASMR attributed to hepatitis C decreased by 43% and 55%, respectively. The association between SDI and ASMRs suggested that hepatitis B and C, respectively, showed an overall decline and stable trends as the SDI improved in the Western Pacific region. Conclusions: : Although the mortality rate from hepatitis B and C decreased from 1990 to 2019, notable variation was observed among 27 Western Pacific countries. Efforts targeting hepatitis B and C prevention and treatment are still required in this region, especially for the pandemic countries.

Universal screening for HCV infection in China: An effectiveness and cost-effectiveness analysis.

Background & Aims: Approximately 10 million people live with chronic HCV infection in China, and less than 20% of people with HCV were diagnosed. We aim to determine the cost-effectiveness of one-time HCV screening compared with no screening in the Chinese population from the healthcare system perspective. Methods: A decision-tree plus Markov model was adopted to project chronic hepatitis C (CHC) prevalence, probability of complications, quality-adjusted life years (QALYs), and costs in the Chinese general population undiagnosed for CHC for different screening strategies. Once CHC was diagnosed, pan-genotypic direct-acting antiviral agent treatment was administered regardless of fibrosis. The population was simulated in a model spanning a lifetime. Input parameters were obtained from published literature. The incremental cost-effectiveness ratio between screening and no screening was estimated. The one-time Chinese gross domestic product per capita in 2021 ($12,558/QALY) was used as the willingness-to-pay threshold. Results: Universal screening in the population aged 3-80 years led to the lowest probability of complications, which yielded a 62% reduction of excess mortality. Compared with no screening, implementing screening and treatment for HCV in populations aged 3-80 years resulted in the greatest marginal QALYs (15.2 per 1,000 population) with an increase in total costs of $109,136. Calculating the incremental cost-effectiveness ratio yields a value of $9,503/QALY (95% uncertainty interval $3,738-$22,566). The robustness of the model was demonstrated through various sensitivity analyses. If the CHC prevalence was over 0.3%, screening could be cost-effective. Conclusions: HCV screening for Chinese people aged 3-80 years may be a cost-effective intervention to reduce the disease burden related to HCV infection. This strategy should certainly be implemented. Impact and implications: This study found that screening Chinese people aged 3-80 years yielded the greatest health benefits and was a cost-effective alternative. The findings indicated that national efforts eliminating HCV should be invested and strengthened in China. The results of this study are important because they provide strong evidence that universal screening can be a cost-effective way to reduce the burden of HCV in China. These findings are important for policymakers, physicians, patients, caregivers, and the public because they promote awareness and inform decision-making for HCV prevention and treatment.

[Spatial-temporal Variations and Pollution Assessment of Heavy Metals in Sediments of Qionghai Lake in Xichang City].

Based on the analysis of the total concentrations of 10 metals in the sediment core and total concentrations and chemical fractions of seven metals in the surface sediments of Qionghai Lake in Xichang City, Sichuan Province, the spatial-temporal characteristics of metal accumulation and pollution over the past century and the potential ecological risk of metals in surface sediments were studied. Before the 1970s, metal concentrations in the sediment core were stable. The total concentrations of Al, Fe, K, and Cr in the sediment core exhibited visible peaks in the 1970s, which were related to the enhanced input of fine-grained topsoil caused by increasing precipitation, lake reclamation, and deforestation. Since the 1990s, the total concentrations of Al, Fe, K, and Cr decreased with the reduced topsoil erosion, whereas the total concentrations of As, Cd, Cu, Pb, and Zn gradually increased or remained stable. The enrichment factor results showed that Cd, Pb, and Zn were the main contaminants, with Cd as the typical contaminant in the sediment core. The Cd contamination started in the 1960s and has remained at a moderate level since the 1990s. In the surface sediments, the total concentrations of Cd were higher in the northwest lake area, and no visible spatial concentration trends of the other metals were displayed. The bioavailable fractions of Cd, Pb, and Zn accounted for 95%, 63%, and 48% of the total metal concentrations on average. Among the bioavailable fractions, Cd was mainly in the acid-soluble fraction, and Pb and Zn were mainly in the reducible and oxidized fractions. The bioavailable fractions of the other metals were less than 27%. The results of total concentrations and bioavailable fractions of metals revealed that Pb and Zn in the surface sediments were slightly or moderately contaminated, and Cd was moderately contaminated on average. Cd contamination was at a severe level in the northwest lake area. The concentrations of anthropogenic Cd, Pb, and Zn in the surface sediments estimated from the total and bioavailable concentrations were comparable (P>0.05), indicating that anthropogenic metals primarily existed in bioavailable fractions in the sediment. Integrating the assessment results from sediment quality guidelines, potential ecological risk index, and chemical forms of metals, Cd in surface sediments may pose a high ecological risk, whereas the other metals has a low ecological risk.

Contamination and source apportionment of metals in urban road dust (Jinan, China) integrating the enrichment factor, receptor models (FA-NNC and PMF), local Moran's index, Pb isotopes and source-oriented health risk.

Contamination and source identifications of metals in urban road dust are critical for remediation and health protection. Receptor models are commonly used for metal source identification, whereas the results are usually subjective and not verified by other indicators. Here we present and discuss a comprehensive approach to study metal contamination and sources in urban road dust (Jinan) in spring and winter by integrating the enrichment factor (EF), receptor models (positive matrix factorization (PMF) and factor analysis with nonnegative constraints (FA-NNC)), local Moran's index, traffic factors and Pb isotopes. Cadmium, Cr, Cu, Pb, Sb, Sn and Zn were the main contaminants, with mean EFs of 2.0-7.1. The EFs were 1.0-1.6 times higher in winter than in spring but exhibited similar spatial trends. Chromium contamination hotspots occurred in the northern area, with other metal contamination hotspots in the central, southeastern and eastern areas. The FA-NNC results indicated Cr contamination primarily resulting from industrial sources and other metal contamination primarily originating from traffic emissions during the two seasons. Coal burning emissions also contributed to Cd, Pb and Zn contamination in winter. FA-NNC model-identified metal sources were verified via traffic factors, atmospheric monitoring and Pb isotopes. The PMF model failed to differentiate Cr contamination from other detrital metals and the above anthropogenic sources, largely due to the model grouping metals by emphasizing hotspots. Considering the FA-NNC results, industrial and traffic sources accounted for 28.5 % (23.3 %) and 44.7 % (28.4 %), respectively, of the metal concentrations in spring (winter), and coal burning emissions contributed 34.3 % in winter. Industrial emissions primarily contributed to the health risks of metals due to the high Cr loading factor, but traffic emissions dominated metal contamination. Through Monte Carlo simulations, Cr had 4.8 % and 0.4 % possibilities posing noncarcinogenic and 18.8 % and 8.2 % possibilities posing carcinogenic risks for children in spring and winter, respectively.

Trends of global burden related to HBV and HCV from 1990 to 2019: An age-period-cohort analysis.

The spread of disease related to Hepatitis B and C poses a significant public health problem. There have been a few studies that examine the effects of cohort and period on the trend of mortality caused by Hepatitis B and C. This analysis aims to use an age-period-cohort (APC) framework to explore trends in mortality attributed to Hepatitis B and C worldwide and in different socio-demographic index (SDI) regions between 1990 and 2019. The data for this analysis were taken from the Global Burden of Disease study, which was used to perform an APC analysis. The age effects reflect differences in exposure to risk factors at different stages of life. The period effects reflect population-wide exposures at a circumscribed year. The cohort effects indicate different risks across birth cohorts. The results of the analysis include both the net drift and local drift, which are reported as the annual percentage change and that by age group. The age-standardized mortality rate for Hepatitis B declined from 12.36 to 6.74 per 100 000, and for Hepatitis C from 8.45 to 6.67 per 100 000 between 1990 and 2019. The net drifts in mortality were -2.41% (95% confidence interval (CI) -2.47 to -2.34) for Hepatitis B and -1.16% (95% CI, -1.23 to -1.09) for Hepatitis C, with negative local drifts in most age groups. Mortality from Hepatitis B increased with age until 50+ years, while mortality from Hepatitis C rose steadily with age. The period effect for Hepatitis B was profound, suggesting effective national efforts in controlling the disease and the need for similar programs for Hepatitis B and C. Mortality varied across the world and had moderate to weak negative correlations with the SDI, which substantially decreases in the high-middle and middle SDI regions, but has persistently high rates in the low SDI region. Global efforts to manage Hepatitis B and C have shown positive trends, but variations in trends were observed across regions with divergent age, cohort, and period effects. The national efforts of a comprehensive strategy are crucial to further strengthen the elimination of Hepatitis B and C.

Microwave assisted extraction, characterization of a polysaccharide from Salvia miltiorrhiza Bunge and its antioxidant effects via ferroptosis-mediated activation of the Nrf2/HO-1 pathway.

A microwave-assisted extraction procedure for the crude Salvia miltiorrhiza polysaccharides (SMPs) obtained from Salvia miltiorrhiza Bunge was optimized. Four independent variables were studied: microwave power, extraction time, solvent-to-solid ratio, and concentration of ethanol, with optimal settings of 1200 W, 12 min, 38, and 86 %, respectively. The SMPs were successively purified by DEAE Sepharose Fast Flow and Sephadex G-100 chromatography to produce a novel polysaccharide termed SMP1. The SMP1 was composed of glucose, galactose, and fructose in a molar ratio of 1:1.67:1.12 with an average molecular weight of 6087 Da. Pharmacological studies showed that SMP1 protected from OGD/R-induced ferroptosis and lipid peroxidation by activating Nrf2/HO-1 pathway in PC12 cells. Our research systematically indicated that polysaccharide could inhibit ferroptosis to alleviate oxidative stress injury, which laid the foundation for the future clinical application of Salvia miltiorrhiza polysaccharide.

An electrochemical sensor for sensitive detection of dopamine based on a COF/Pt/MWCNT-COOH nanocomposite.

Herein, an electrochemical sensor was developed for sensitive detection of dopamine (DA) based on a novel COF-based nanocomposite named COF/Pt/MWCNT-COOH, which possesses large specific surface area, excellent electrical conductivity, and high catalytic activity, thus broadening the application of COFs in the electrochemical sensing area.

Pharmacophore-probe reaction guided purification to precisely identify electrophilic withanolides from Tubocapsicum anomalum Makino and their anti-TNBC activity.

Pharmacophore-probe reaction guided purification strategy can reduce the workload of natural product chemistry and raise the probability of obtaining undescribed and high-bioactive target compounds. In this study, a probe of N-acetyl cysteine (NAC) was used to confirm the pharmacophore of Tubocapsicum anomalum (Franch. et Sav.) Makino. Furthermore, a thiol probe named 4-bromothiophenol (BTP) guided the discovery of three undescribed (1-3) and nine known (4-12) electrophilic withanolides (EWs) featured potential anti-triple negative breast cancer (TNBC) pharmacophore. Notably, co-incubation with BTP made the single crystals of EW conjugates much more accessible, which facilitated the absolute configuration determination of EWs. Electrophilic natural products with the potential of thio-alkylation modification and covalent inhibition key proteins in tumor cell signal transduction pathways may display significant antitumor activity. The MTT results indicated that most EWs showed anti-TNBC activity and were expected to develop anti-TNBC candidate drugs with high selectivity and novel mechanism.

Structural characterization of a polysaccharide from Trametes sanguinea Lloyd with immune-enhancing activity via activation of TLR4.

A bioactive polysaccharide (TS2-2A) with a molecular weight of 15 kDa was isolated from Trametes sanguinea Lloyd, a medicinal food homologous fungus, by water extraction-alcohol precipitation and chromatographic separation. NMR analysis of polysaccharide and MS/MS analysis of its oligosaccharide indicated that TS2-2A featured a novel straight chain with a backbone of 1,3-α-d-glucopyranose and 1,4-ß-d-glucopyranose at a molar ratio of 1:4. Moreover, TS2-2A, recognized by Toll-like receptor 4 (TLR4), stimulated RAW 264.7 macrophages to release related cytokines and contributed to immune-enhancing effects. Briefly, with remarkable immune-enhancing activity and noncytotoxicity, TS2-2A was proposed to be a potential immune enhancer for supplementing drugs or functional foods.

Structural Characterization and Tumor Microvascular Inhibition Activity of Total Polysaccharide from Trametes sanguinea Lloyd.

Trametes sanguinea Lloyd total polysaccharide (TsLTP), was obtained by water extraction and ethanol precipitation from T. sanguinea. The structural characterization of TsLTP was elucidated mutually by TsL1 and TsL2, whose mass ratio is 1: 4. TsL1 is mainly composed of mannose, glucose, galactose, and fucose, and consist of T-Linked-Fucp, T-Linked-Manp, T-Linked-Galp, 1,4-Linked-Manp, 1,4-Linked-Glcp, 1,6-Linked-Manp, 1,6-Linked-Galp, 1,3,4-Linked-Glcp, 1,4,6-Linked-Glcp and 1,3,6-Linked-Glcp, with a molar ratio of 2.1: 1.7: 1.4: 1.0: 3.6: 2.0: 8.6: 1.3: 2.2: 1.2, while TsL2 mainly comprise of glucose and consist of T-Linked-Glcp, 1,3-Linked-Glcp, 1,4-Linked-Glcp and 1,4,6-Linked-Glcp, with a molar ratio of 1.0: 2.1: 7.6: 1.4. TsLTP exhibited strong inhibitory effects on the migration, invasion, and tube formation of human umbilical vein endothelial cells (iHUVECs) and chick embryo chorioallantoic membrane (CAM) angiogenesis, whereas no inhibitory activity on human TNBC cell lines. Taken together, our study suggests that TsLTP possesses a significant inhibition of tumor microvascular activity both in vitro and in vivo. The study of TsLTP with novel monosaccharide composition and tumor microvascular inhibitory activity might be a beneficial attempt for application of polysaccharide from the genus Trametes in tumor therapy.

A decision support system for primary headache developed through machine learning.

BACKGROUND: Primary headache is a disorder with a high incidence and low diagnostic accuracy; the incidence of migraine and tension-type headache ranks first among primary headaches. Artificial intelligence (AI) decision support systems have shown great potential in the medical field. Therefore, we attempt to use machine learning to build a clinical decision-making system for primary headaches. METHODS: The demographic data and headache characteristics of 173 patients were collected by questionnaires. Decision tree, random forest, gradient boosting algorithm and support vector machine (SVM) models were used to construct a discriminant model and a confusion matrix was used to calculate the evaluation indicators of the models. Furthermore, we have carried out feature selection through univariate statistical analysis and machine learning. RESULTS: In the models, the accuracy, F1 score were calculated through the confusion matrix. The logistic regression model has the best discrimination effect, with the accuracy reaching 0.84 and the area under the ROC curve also being the largest at 0.90. Furthermore, we identified the most important factors for distinguishing the two disorders through statistical analysis and machine learning: nausea/vomiting and photophobia/phonophobia. These two factors represent potential independent factors for the identification of migraines and tension-type headaches, with the accuracy reaching 0.74 and the area under the ROC curve being at 0.74. CONCLUSIONS: Applying machine learning to the decision-making system for primary headaches can achieve a high diagnostic accuracy. Among them, the discrimination effect obtained by the integrated algorithm is significantly better than that of a single learner. Second, nausea/vomiting, photophobia/phonophobia may be the most important factors for distinguishing migraine from tension-type headaches.

A dual-amplification mode and Cu-based metal-organic frameworks mediated electrochemical biosensor for sensitive detection of microRNA.

In this work, we developed a novel label-free and highly sensitive electrochemical (EC) biosensor for detection of microRNA (miRNA), which was based on the target-triggered and the Cu-based metal-organic frameworks (Cu-MOFs) mediated CHA-HCR dual-amplification process. Initially, the target miRNA triggered the catalytic hairpin assembly (CHA) process of hairpin DNA 1 (H1) and hairpin DNA 2 (H2) to produce massive double-stranded DNA (H1/H2) which could hybridize with the single-stranded DNA 1 (P1) to form capture probe (P1/H1/H2) on electrode surface, realizing the first amplification of input signals. Subsequently, hybridization chain reaction (HCR) between signal probe (H3-AuNPs/Cu-MOFs) and hairpin DNA 4 (H4) was activated by above capture probe (P1/H1/H2), leading to the second amplification of input signals. After the HCR process, numerous Cu-MOFs were immobilized on the electrode surface, which brought out the enhancement of electrochemical signals generating by Cu-MOFs. Herein, Cu-MOFs not only offered the lager surface area to decorate with gold nanoparticles (AuNPs) and hairpin DNA 3 (H3), but also served as the signal probe (H3-AuNPs/Cu-MOFs) to produce electrochemical signals by hybridizing with the capture probe on electrode surface. Therefore, the ingenious design of CHA-HCR-Cu-MOFs scheme enables the sensitive analysis of microRNA-21 (miR-21) with a broad linear range from 0.1 fM to 100 pM and a lower LOD of 0.02 fM. In addition, the outstanding specificity of this sensing strategy allows it successfully to be applied for determining miR-21 in real biological samples.

Hepatitis B and C mortality from 1990 to 2019 in China: a Bayesian age-period-cohort analysis.

Background: Significant decreases in hepatitis B virus (HBV) and hepatitis C virus (HCV) infections have been observed in China, but both remain leading public health challenges. Estimating the components and trends in HBV and HCV mortality is vital for disease control planning. The current analysis investigated time trends in hepatitis B and C mortality and the relationships with age, period, and birth cohort from 1990 to 2019. We also made projections for 2030-2034 in China. Methods: Mortality data related to hepatitis B and C were obtained from the Global Burden of Disease (GBD) study, which was stratified by complications, age, sex, and specific geographical locations. An age-period-cohort (APC) analytical framework was adopted to measure age, period, and cohort effects, which fits a log-linear Poisson model over a Lexis diagram of observed rates and quantifies the additive effects of age, period, and birth cohorts. We estimated longitudinal age curves (expected longitudinal age-specific rates), net drift (overall annual percentage change), local drift (annual percentage change in each age group), period, and cohort relative risks. A Bayesian APC analysis was used to project future age-specific hepatitis B and C deaths. Results: In China, the age-standardized mortality rate (ASMR) of hepatitis B and C decreased by 67% and 58% from 1990 to 2019, respectively. The overall annual percentage changes in hepatitis B and C were -4.97% and -6.49% for males and -3.85% and -6.09% for females, respectively. After adjusting for period and cohort effects, we observed an exponential increase in hepatitis C mortality with age, with the Bell-like curves peaking at approximately 50 years old for hepatitis B. The Bayesian APC analysis projected that hepatitis B and C deaths would decrease dramatically by 42% and 22% for the periods 2016-2019 and 2030-2034, respectively. The declines in ASMRs related to hepatitis B and C were associated with the improvements in the Chinese Socio-Demographic Index. Conclusions: Although the burden of hepatitis B and C mortality is likely to continue declining in China, the hepatitis B and C mortality was still high. Therefore, the national efforts should still be strengthened to achieve the global hepatitis elimination targets.

Electrochemical Immunosensor for Cardiac Troponin I Detection Based on Covalent Organic Framework and Enzyme-Catalyzed Signal Amplification.

Herein, a highly sensitive electrochemical immunosensor was presented for the cardiac troponin I (cTnI) determination using a multifunctional covalent organic framework-based nanocomposite (HRP-Ab2-Au-COF) as the signal amplification probe. The spherical COF with a large surface area was synthesized in a short time by a simple solution-based method at room temperature. The good biocompatibility, low toxicity, and high stability in water of the COF guarantee its application in biosensing. Besides, its high porosity makes it an excellent carrier for loading abundant horseradish peroxidase (HRP). The modified gold nanoparticles on the surface of COF not only provide a load platform for secondary antibody (Ab2) but also improve the conductivity of COF. Under the synergistic effect of the hydrogen peroxide (H2O2) and HRP, hydroquinone (HQ) in the solution is catalytically oxidized to benzoquinone (BQ), which is then reduced on the electrode surface to generate the electrochemical signal. The designed probes not only show the specific recognition behavior of Ab2 to cTnI but also improve the sensitivity of the biosensing system due to the signal amplification caused by the excellent enzyme catalytic performance of HRP. Based on the H2O2-HRP-HQ signal amplification system, the biosensor for cTnI was fabricated and exhibited a linear response as a function of logarithmic cTnI concentration ranging from 5 pg/mL to 10 ng/mL, and the detection limit was 1.7 pg/mL. Moreover, the biosensor exhibited excellent recovery and reproducibility in the actual sample testing. This work provided a simple approach to determine cTnI quantitatively in practical samples and broadened the utilization scope of the COF-based nanocomposite in the electrochemical immunosensor.

Electrochemiluminescence Biosensor Based on Entropy-Driven Amplification and a Tetrahedral DNA Nanostructure for miRNA-133a Detection.

The early and rapid diagnosis of acute myocardial infarction (AMI) is of great significance to its treatment. Here, we developed an electrochemiluminescence biosensor based on an entropy-driven strand displacement reaction (ETSD) and a tetrahedral DNA nanostructure (TDN) for the detection of the potential AMI biomarker microRNA-133a. In the presence of the target, numerous Ru(bpy)32+-labeled signal probes (SP) were released from the preformed three-strand complexes through the process of ETSD. The ETSD reaction cycle greatly amplified the input signal of the target. The released SP could be captured by the TDN-engineered biosensing interface to generate a strong ECL signal. The rigid structure of TDN could significantly improve the hybridization efficiency. With the assistant of double amplification of TDN and ETSD, the developed biosensor has a good linear response ranging from 1 fM to 1 nM for microRNA-133a, and the detection limit is 0.33 fM. Additionally, the constructed biosensor has excellent repeatability and selectivity, demonstrating that the biosensor possesses a great application prospect in clinical diagnosis.

Label-free immunosensor for cardiac troponin I detection based on aggregation-induced electrochemiluminescence of a distyrylarylene derivative.

Herein, the aggregation-induced electrochemiluminescence (AIECL) of a distyrylarylene derivative, 4,4'-bis(2,2-diphenylvinyl)-1,1'-biphenyl (DPVBi), was investigated for the first time. This luminophore exhibits significantly enhanced photoluminescence (PL) and electrochemiluminescence (ECL) emission with the increases of water content in organic/water mixtures. This high luminescence efficiency of DPVBi in aggregate state is due to the fact that the aggregates can reduce the energy loss by restricting the intramolecular motions. The ECL behavior of DPVBi in acetonitrile was investigated by ECL transients and so-called "half-scan" technology, where singlet-singlet annihilation ECL was generated under continuous potential switching. The DPVBi nanobulks (DPVBi NBs) were prepared to improve its application in aqueous media, which could be conveniently cast on electrode surface for developing sensing platform due to its good film-forming nature. The constructed heterogeneous AIECL platform can produce reductive-oxidative and oxidative-reductive ECL by using trimethylamine (TEA) and potassium peroxodisulfate (K2S2O8) as coreactant. On the basis of the higher ECL efficiency of DPVBi NBs/TEA system, a label free immunosensor for cardiac troponin I (cTnI) was developed with the assistance of electrodeposited gold nanoparticles, and it showed a wide linear range of 20 ng/mL~100 fg/mL and low detection limit of 43 fg/mL. Moreover, the constructed immunosensor also exhibited good specificity, stability and satisfied performance in practical sample analysis.

Rational Construction of Ruthenium-Cobalt Oxides Heterostructure in ZIFs-Derived Double-Shelled Hollow Polyhedrons for Efficient Hydrogen Evolution Reaction.

Transition metal oxides (TMOs) and their heterostructure hybrids have emerged as promising candidates for hydrogen evolution reaction (HER) electrocatalysts based on the recent technological breakthroughs and significant advances. Herein, Ru-Co oxides/Co3 O4 double-shelled hollow polyhedrons (RCO/Co3 O4 -350 DSHPs) with Ru-Co oxides as an outer shell and Co3 O4 as an inner shell by pyrolysis of core-shelled structured RuCo(OH)x @zeolitic-imidazolate-framework-67 derivate at 350 °C are constructed. The unique double-shelled hollow structure provides the large active surface area with rich exposure spaces for the penetration/diffusion of active species and the heterogeneous interface in Ru-Co oxides benefits the electron transfer, simultaneously accelerating the surface electrochemical reactions during HER process. The theory computation further indicates that the existence of heterointerface in RCO/Co3 O4 -350 DSHPs optimize the electronic configuration and further weaken the energy barrier in the HER process, promoting the catalytic activity. As a result, the obtained RCO/Co3 O4 -350 DSHPs exhibit outstanding HER performance with a low overpotential of 21 mV at 10 mA cm-2 , small Tafel slope of 67 mV dec-1 , and robust stability in 1.0 m KOH. This strategy opens new avenues for designing TMOs with the special structure in electrochemical applications.