Prevalence and influencing factors of PTSD symptoms among healthcare workers: A multicenter cross-sectional study during the surge period of the COVID-19 pandemic since December 2022 in the Chinese mainland.

BACKGROUND: China has experienced a surge period of COVID-19 pandemic since December 2022. Healthcare workers (HCWs) were exposed to huge workload under high risk of being infected, and significant levels of trauma, which might cause Post-traumatic Stress Disorders (PTSD) symptoms in HCWs. OBJECTIVES: To identify the prevalence of PTSD symptoms among HCWs in the Chinese mainland during the surge period of the COVID-19 pandemic; to explore their psycho-social factors of PTSD symptoms. METHODS: A multicenter cross-sectional study was conducted among HCWs in Chinese mainland from January 5 to February 9, 2023, covering seven geographical regions. 6552 participants were recruited by convenience sampling. Data were collected on demographic characteristics, work-related factors, and psychological factors by online questionnaires. Univariate analysis and binary logistic regression were used to determine the influencing factors of PTSD symptoms. RESULTS: The prevalence of PTSD symptoms among HCWs was 37.49 %. A higher level of mindfulness, resilience, and perceived social support were protective factors. Female gender, nurses, higher educational attainment, married status, more working years, higher perceived risk of contracting COVID-19 due to work, and higher perceived work intensity were risk factors. CONCLUSION: High prevalence of PTSD symptoms among HCWs necessitates psychological interventions. Tailored interventions, designed by professional psychiatrists, should be tailored to address the stressors. A comprehensive approach, incorporating mindfulness, resilience-building, and perceived social support enhancement, is vital to bolster the mental well-being of HCWs exposed to traumatic events, thus mitigating the impact of PTSD effectively. Additionally, it is essential to provide support to HCWs with other potential risk factors.

Segregation and integration of sensory features by flexible temporal characteristics of independent neural representations.

Segregation and integration are two fundamental yet competing computations in cognition. For example, in serial speech processing, stable perception necessitates the sequential establishment of perceptual representations to remove irrelevant features for achieving invariance. Whereas multiple features need to combine to create a coherent percept. How to simultaneously achieve seemingly contradicted computations of segregation and integration in a serial process is unclear. To investigate their neural mechanisms, we used loudness and lexical tones as a research model and employed a novel multilevel oddball paradigm with Electroencephalogram (EEG) recordings to explore the dynamics of mismatch negativity (MMN) responses to their deviants. When two types of deviants were presented separately, distinct topographies of MMNs to loudness and tones were observed at different latencies (loudness earlier), supporting the sequential dynamics of independent representations for two features. When they changed simultaneously, the latency of responses to tones became shorter and aligned with that to loudness, while the topographies remained independent, yielding the combined MMN as a linear additive of single MMNs of loudness and tones. These results suggest that neural dynamics can be temporally synchronized to distinct sensory features and balance the computational demands of segregation and integration, grounding for invariance and feature binding in serial processing.

Effect of allyl isothiocyanate on oxidative stress in COPD via the AhR / CYP1A1 and Nrf2 / NQO1 pathways and the underlying mechanism.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is currently the third leading cause of death globally. Oxidative stress affects various molecular mechanisms and is the main driving factor of COPD. Ally isothiocyanate (AITC) is an effective component of Semen Sinapis Albae, which has favorable effects for the treatment of COPD, but its mechanism has not been fully elucidated. PURPOSE: This study aimed to elucidate the antioxidant effect of AITC on COPD and its molecular mechanism, and preliminarily determine the role of AhR in the progression of COPD. STUDY DESIGN: The COPD rat model was established by smoking combined with intratracheal instillation of lipopolysaccharide. Different doses of AITC, positive control drug acetylcysteine, AhR inhibitor alpha-naphthoflavone, and agonist beta-naphthoflavone were administered by gavage. Human bronchial epithelial cells induced by cigarette smoke extract (CSE) were used in an in vitro model to explore the molecular mechanisms of AITC. METHODS: The effects of AITC on lung function and oxidative stress in rats were evaluated in vivo using the respiratory function test, white blood cell count, enzyme-linked immunosorbent assay, and histological staining. The changes in protein expression in the lung tissue were detected by immunohistochemistry and Western blotting. RT-PCR, western blotting, and immunofluorescence were used to explore the molecular mechanisms of AITC. Enzyme-linked immunosorbent assay, reactive oxygen species probing, and flow cytometry were used to determine the antioxidant effect of AITC. RESULTS: AITC can improve the lung function of rats with COPD, restore lung tissue structure, improve oxidative stress, reduce inflammation, and inhibit lung cell apoptosis. AITC reversed the upregulation of AhR and CYP1A1 and the down-regulation of Nrf2 and NQO1 in the lung tissues of rats with COPD. CSE stimulation can increase the expressions of AhR and CYP1A1 and decrease the expressions of Nrf2 and NQO1 in 16HBE cells, leading to severe oxidative stress and inflammatory response and, ultimately, apoptosis. AITC inhibited AhR and CYP1A1 expressions, induced Nrf2 and NQO1 expressions, promoted Nrf2 nuclear translocation, and improved CSE-induced toxicological effects. CONCLUSION: AITC may improve lung oxidative stress by inhibiting the AhR / CYP1A1 and activating the Nrf2 / NQO1 pathways, thereby delaying the pathological progression of COPD.

Diversity and structural analysis of rhizosphere soil microbial communities in wild and cultivated Rhizoma Atractylodis Macrocephalae and their effects on the accumulation of active components.

Rhizosphere microorganisms are the main factors affecting the formation of high quality medicinal materials and promoting the accumulation of secondary metabolites. However, the composition, diversity, and function of rhizosphere microbial communities in endangered wild and cultivated Rhizoma Atractylodis Macrocephalae (RAM) and their relationships with active component accumulation have remained unclear. In this study, high-throughput sequencing and correlation analysis were used to study the rhizosphere microbial community diversity (bacteria and fungi) of three RAM species and its correlation with the accumulation of polysaccharides, atractylone, and lactones (I, II, and III). A total of 24 phyla, 46 classes, and 110 genera were detected. The dominant taxa were Proteobacteria, Ascomycota, and Basidiomycota. The microbial communities in both wild and artificially cultivated soil samples were extremely species-rich, but there were some differences in their structure and the relative abundances of microorganism taxa. Meanwhile, the contents of effective components in wild RAM were significantly higher than those in cultivated RAM. Correlation analysis showed that 16 bacterial and 10 fungal genera were positively or negatively correlated with active ingredient accumulation. These results showed that rhizosphere microorganisms could play an important role in component accumulation and might lay a foundation for future research on endangered materials.

Allyl isothiocyanate dry powder inhaler based on cyclodextrin-metal organic frameworks for pulmonary delivery.

In this study, allyl isothiocyanate (AITC) was prepared as the dry powder inhalation by loading cyclodextrin metal-organic framework (CD-MOF) to enhance pulmonary delivery. ß-CD-MOF and γ-CD-MOF both could be used to carry AITC with the optimal loading conditions (50˚C, n CD: n AITC = 1:7, 7 h). Compared with ß-CD-MOF, γ-CD-MOF had more advantages in AITC loading due to its high drug loading and stable crystal morphology. The particle size and the mass median aerodynamic diameter of γ-CD-MOF-AITC were accorded with the aerodynamic characteristics of lung inhalation. γ-CD-MOF-AITC might be deposited effectively in the deep lung, and the release rate of AITC reached over 90% within 5 min. Meanwhile, it had good pulmonary local tolerance, permeability, and no significant toxicity. Such results indicated that γ-CD-MOF could be used as a dry powder inhaler carrier to deliver safely AITC to lung and increase its pulmonary absorption.

Preparation and in Vitro Evaluation of Osmotic-Pump Lorcaserin-hydrochloride Controlled-Release Tablets.

Long-term and constant-release osmotic-pump lorcaserin hydrochloride controlled-release tablets (OP LH CRTs) were prepared, to investigate the influencing factors of LH release and optimize the formulation. The mechanism of release of LH from OP LH CRTs in vitro was investigated. By establishing a high-efficiency method for measuring LH release in vitro, and optimizing it by single-factor and orthogonal experiments, the best formulation of OP LH CRTs was determined. Then, the optimal prescription of OP LH CRTs was: LH = 20.8 mg; mannitol = 100 mg, microcrystalline cellulose = 125 mg; magnesium stearate = 5 mg; cellulose acetate = 3%; polyethylene glycol 400 = 10%; dibutyl phthalate = 10%; Wetting agent and binder was 3% polyvinyl pyrrolidone (PVP) K30 ethanol solution; aperture diameter = 0.8 mm; the coating gained 3% weight. And finally, prepared OP LH CRTs were released at a constant rate in vitro and sustained for 16 h with good reproducibility between batches. Using an orthogonal experimental design, OP LH CRTs with remarkable zero-order release characteristics within 16 h were obtained, and formulation optimization was realized.

Metformin alleviates chronic obstructive pulmonary disease and cigarette smoke extract-induced glucocorticoid resistance by activating the nuclear factor E2-related factor 2/heme oxygenase-1 signaling pathway.

Chronic obstructive pulmonary disease (COPD) is an important healthcare problem worldwide. Often, glucocorticoid (GC) resistance develops during COPD treatment. As a classic hypoglycemic drug, metformin (MET) can be used as a treatment strategy for COPD due to its anti-inflammatory and antioxidant effects, but its specific mechanism of action is not known. We aimed to clarify the role of MET on COPD and cigarette smoke extract (CSE)-induced GC resistance. Through establishment of a COPD model in rats, we found that MET could improve lung function, reduce pathological injury, as well as reduce the level of inflammation and oxidative stress in COPD, and upregulate expression of nuclear factor E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), multidrug resistance protein 1 (MRP1), and histone deacetylase 2 (HDAC2). By establishing a model of GC resistance in human bronchial epithelial cells stimulated by CSE, we found that MET reduced secretion of interleukin-8, and could upregulate expression of Nrf2, HO-1, MRP1, and HDAC2. MET could also increase the inhibition of MRP1 efflux by MK571 significantly, and increase expression of HDAC2 mRNA and protein. In conclusion, MET may upregulate MRP1 expression by activating the Nrf2/HO-1 signaling pathway, and then regulate expression of HDAC2 protein to reduce GC resistance.

Neural responses to facial attractiveness in the judgments of moral goodness and moral beauty.

The judgments of moral goodness and moral beauty objectively refer to the perception and evaluation of moral traits, which are generally influenced by facial attractiveness. For centuries, people have equated beauty with the possession of positive qualities, but it is not clear whether the association between beauty and positive qualities exerts a similarly implicit influence on people's responses to moral goodness and moral beauty, how it affects those responses, and what is the neural basis for such an effect. The present study is the first to examine the neural responses to facial attractiveness in the judgments of moral goodness and moral beauty. We found that beautiful faces in both moral judgments activated the left ventral occipitotemporal cortices sensitive to the geometric configuration of the faces, demonstrating that both moral goodness and moral beauty required the automatic visual analysis of geometrical configuration of attractive faces. In addition, compared to beautiful faces during moral goodness judgment, beautiful faces during moral beauty judgment induced unique activity in the ventral medial prefrontal cortex and midline cortical structures involved in the emotional-valenced information about attractive faces. The opposite comparison elicited specific activity in the left superior temporal cortex and premotor area, which play a critical role in the recognition of facial identity. Our results demonstrated that the neural responses to facial attractiveness in the process of higher order moral decision-makings exhibit both task-general and task-specific characteristics. Our findings contribute to the understanding of the essence of the relationship between morality and aesthetics.

Effects of allyl isothiocyanate on the expression, function, and its mechanism of ABCA1 and ABCG1 in pulmonary of COPD rats.

BACKGROUND AND AIMS: Allyl isothiocyanate(AITC) has been shown to play an important role in the improved symptoms of chronic obstructive pulmonary disease(COPD) and the inhibition of inflammation, but the role in COPD lipid metabolism disorder and the molecular mechanism remains unclear. We aimed to explore whether and how AITC affects COPD by regulating lipid metabolism and inflammatory response. METHODS: The COPD rat model was established by cigarette smoke exposure. Cigarette smoke extract stimulated 16HBE cells to induce a cell model. The effect of AITC treatment was detected by lung function test, H&E staining, Oil red O staining, immunohistochemistry, ELISA, CCK-8, HPLC, fluorescence efflux test, siRNA, RT-PCR, and Western blotting. Biological analysis was performed to analyze the results. Graphpad Prism 8.0 software was used for statistical analysis. RESULTS: AITC can improve lung function and pathological injury in COPD rats. The levels of IL-1 ß and TNF- α in the AITC treatment group were significantly lower than those in the model group(P < 0.05), and the lipid metabolism was also improved (P < 0.05). AITC reverses CSE-induced down-regulation of LXR α, ABCA1, and ABCG1 expression and function in a time-and concentration-dependent manner (P < 0.05). AITC regulates the cholesterol metabolism disorder induced by CSE in NR8383 cells and attenuates macrophage inflammation (P < 0.05). In addition, after silencing LXR α with siRNA, the effect of AITC was also inhibited. CONCLUSION: These results suggest that AITC improves COPD by promoting RCT process and reducing inflammatory response via activating LXR pathways.

Effects of nitrogen application rate on the photosynthetic pigment, leaf fluorescence characteristics, and yield of indica hybrid rice and their interrelations.

A field experiment employing the rice cultivars Qyou6 and Yixiangyou2115 as materials and different nitrogen application rates was conducted in Huangping County, Guizhou Province in 2019 to determine the effects of nitrogen application rate on photosynthetic pigments, leaf fluorescence characteristics, yield, and their interrelations in indica hybrid rice. The results showed that photosynthetic pigment contents generally increased with increasing nitrogen application rate. As the nitrogen rate increased, the maximal quantum yield of PSII (Fv/Fm), actual quantum yield of PSII (ΦPSII), and relative electron transfer rate at PSII (ETR) first decreased and then increased at the booting stage; Fv/Fm and ΦPSII decreased while ETR first increased and then decreased at the heading stage; nevertheless, Fv/Fm and ΦPSII first decreased and then increased but ETR was just the opposite at the maturity stage. Non-photochemical quenching coefficient (qN) and quantum yield of regulatory energy dissipation at PSII (Y(NPQ)) first increased and then decreased whereas quantum yield of non-regulatory energy dissipation at PSII (Y(NO)) first decreased and then increased at the booting, heading, and maturity stages with increasing nitrogen application rate. Photochemical quenching coefficient (qP) showed an increasing trend as the nitrogen rate increased in the range of 150-300 kg/ha at the heading and maturity stages. Photosynthetic pigments, leaf fluorescence characteristics, and yield and its components were significantly correlated. First, chlorophylls a and b were significantly negatively correlated with Fv/Fm while significantly positively correlated with qP at the heading stage. Secondly, Carotenoids were significantly positively correlated with the effective panicle number (EPN) at the booting stage while significantly negatively correlated with the spikelets per panicle (SPP) at the heading stage. Chlorophyll a and carotenoids were significantly positively correlated with EPN but significantly negatively correlated with spikelet filling (SF) at the maturity stage. In addition, qP was significantly negatively correlated with EPN at the booting stage. At the heading stage, Fv/Fm and Y(NO) were significantly negatively correlated with EPN and SPP, respectively, and Fv/Fm and ΦPSII were significantly positively related to SF. Moreover, qP was extremely significantly positively related to EPN whereas Fv/Fm was extremely significantly negatively correlated with grain yield at the maturity stage. Appropriate nitrogen application rates can enhance photosynthetic pigment contents, improve the photochemical efficiency and proportion of the open part of the reaction center of PSII, and promote the quantum efficiency and self-protection ability of PSII, thereby increasing photosynthetic efficiency and yield. Under the conditions adopted in this experiment, a parabolic relationship was observed between the nitrogen application rate and grain yield. The regression analysis results showed that the best nitrogen application rate of indica hybrid rice is 168.16 kg ha-1 and the highest yield is 11,804.87 kg ha-1.

Can you voluntarily forget what you are planning to forget? Behavioral evidence for the underlying truth of the cost-benefit principle.

Directed forgetting (DF) or intentional forgetting can impair the recall of items cued to be forgotten (so-called cost) but can also improve the recall of items cued to be remembered (so-called benefit), following the cost-benefit principle. However, whether the forget cue is the cause of intentional forgetting is doubtful. Several studies suggest that intentional forgetting is extremely hard by introducing a noncue condition, but it is not enough to explain how the cost-benefit principle works without forgetting. Here, two series of experiments are designed to test the voluntary control ability of attentional resource allocation from memory benefits to costs. In the Experiment 1 series, we changed the position and content of cues, replicating the DF effect and the analogous effect without a forget cue. The results showed that precueing can mildly upregulate memory attentional resources to improve performance while incurring memory costs for other items. Since forced remembering can also induce memory costs and benefits, the cost-benefit principle may not be attributed to DF. In the Experiment 2 series, we further demonstrated that memory costs and benefits exist when implicit cues are employed. Overall, when the results of all memory costs in the above experiments are compared with a noncue condition as the baseline in Experiment 2c, there exist no significant differences. The current results indicate that we can voluntarily upregulate our memory performance for certain items but cannot voluntarily downregulate memory encoding, generalizing the selective attentional resource control account to the cost-benefit principle beyond the directed-forgetting effect.

Label-Free Ratiometric Electrochemiluminescence Aptasensor Based on Nanographene Oxide Wrapped Titanium Dioxide Nanoparticles with Potential-Resolved Electrochemiluminescence.

A new "one-pot" hydrothermal method was developed for the preparation of electrochemiluminescence (ECL) nanoluminophores nanographene oxide wrapping titanium dioxide (nGO@TiO2 NLPs). The characterization demonstrated that nGO@TiO2 NLPs possessed a core-shell-like shape. The nGO@TiO2 NLPs exhibited potential-resolved ECL property in neutral aqueous solution using K2S2O8 as a coreactant. On this basis, a label-free ratiometric ECL aptasensor was designed. nGO@TiO2 NLPs were used to fabricate the ECL interface for target recognition, potential-resolved ECL signal generation, and amplification. In the presence of cardiac troponin I (cTnI), the aptamer resides from the electrode surface owing to its rigidity, resulting in a reduction in charge transfer resistance of the modified working electrode and a ratio enhancement of two ECL signals of nGO@TiO2 NLPs. According to the increased ECL ratio, cTnI could be determined by the ratiometric ECL aptasensor, with a linear dynamic range of 1.0 × 10-13-1.0 × 10-10 mol/L and a detection limit of 4.0 × 10-14 mol/L, which is superior to most reported electrochemical methods. This label-free ratiometric ECL strategy with self-calibrating ability and accurate, ultrasensitive, rapid, specific analytical performance showed great promise in biosensing and clinical diagnosis. The developed strategy might extend for the sensing of other protein biomarkers by using corresponding antibodies or aptamers as recognition elements.

Highly chemiluminescent TiO2/tetra(4-carboxyphenyl)porphyrin/N-(4-aminobutyl)-N-ethylisoluminol nanoluminophores for detection of heart disease biomarker copeptin based on chemiluminescence resonance energy transfer.

In this work, the chemiluminescence (CL) property of 5,10,15,20-tetrakis(4-carboxyphenyl)-porphyrin- and N-(4-aminobutyl)-N-ethylisoluminol-functionalized TiO2 nanoparticles (TiO2-TCPP-ABEI nanoluminophores) was studied for the first time. It was found that TiO2-TCPP-ABEI nanoluminophores exhibited excellent CL activity in the presence of H2O2. The CL mechanism has been proposed due to the reaction of ABEI with H2O2 and catalytic effect of TiO2 and TCPP. Furthermore, trisodium citrate-stabilized gold nanoparticles were observed to effectively quench the CL of TiO2-TCPP-ABEI due to CL resonance energy transfer (CRET). On this basis, a sensitive and selective CRET-based immunoassay was developed for the determination of copeptin by using TiO2-TCPP-ABEI nanoluminophores as both CL nanointerface and energy donor, and using cit-AuNPs as an effective energy receptor. The immunoassay exhibited a wide dynamic range from 5 × 10-12 to 1 × 10-9 g mL-1 with a low detection limit of 1.54 × 10-12 g mL-1, which was superior to previously reported CL-based immunoassays. It was successfully applied for the determination of copeptin in serum samples, which would provide a good practical perspective on the clinical diagnosis. This strategy may also be used for the detection of other antigens if corresponding antibodies are available. Graphical abstract.

Coreactant-Free and Label-Free Eletrochemiluminescence Immunosensor for Copeptin Based on Luminescent Immuno-Gold Nanoassemblies.

In this work, the eletrochemiluminescence (ECL) behavior of Cu2+/cysteine complexes and N-(aminobutyl)- N-(ethylisoluminol) (ABEI) functionalized gold nanoparticles combined with chitosan (Cu2+-Cys-ABEI-GNPs-CS) were studied by cyclic voltammetry and a double-step potential, which exhibited excellent ECL properties without any coreactant. It was found that the ECL intensity of Cu2+-Cys-ABEI-GNPs-CS could increase at least 1 order of magnitude compared with that of Cu2+-Cys-ABEI-GNPs. Furthermore, a coreactant-free and label-free ECL immunosensor has been established for the determination of early acute myocardial infarction biomarker copeptin based on luminescent immuno-gold nanoassemblys consisting of Cu2+-Cys-ABEI-GNPs-CS and immuno-gold nanoparticles prepared by connecting copeptin antibody with trisodium citrate stabilized gold nanoparticles. In the presence of copeptin, an obvious decrease in ECL intensity was observed due to the formation of antibody-antigen immunocomplex, which could be used for the determination of copeptin in the range of 2.0 × 10-14-1.0 × 10-11 mol/L with a detection limit of 5.18 × 10-15 mol/L. The detection limit of the ECL immunosensor is at least 2 orders of magnitude lower than that of sandwich immunoassays based on labeling technology. Also, the ECL immunosensor does not need any coreactant and avoids complicated labeling and purification procedure. It is ultrasensitive, simple, specific, and low-cost. This work reveals that the proposed luminescent immuno-gold nanoassemblies are ideal nanointerfaces for the construction of immunosensors. The proposed strategy may be used for the determination of other antigens if corresponding antibodies are available.

Potential-Resolved Multicolor Electrochemiluminescence of N-(4-Aminobutyl)-N-ethylisoluminol/tetra(4-carboxyphenyl)porphyrin/TiO2 Nanoluminophores.

Most electrochemiluminescence (ECL) studies involve single luminophore with a unique emission process, which severely limits its applications. Recently, multicolor ECL has attracted considerable interests. Herein, we report a novel nanoluminophore prepared by coating 5,10,15,20-tetrakis(4-carboxyphenyl)-porphyrin (TCPP) and N-(4-aminobutyl)-N-ethylisoluminol (ABEI) on the surface of TiO2 nanoparticles (TiO2-TCPP-ABEI), which exhibited unique potential-resolved multicolor ECL emissions using H2O2 and K2S2O8 as coreactants in an aqueous solution. Three ECL peaks, ECL-1 at 458 nm, ECL-2 at 686 nm, and ECL-3 at 529 nm, were obtained with peak potentials of 1.05, -1.65, and -1.85 V, which were attributed to the ECL emission of ABEI, TCPP, and TiO2 moiety of the nanoluminophores, respectively. Potential-resolved multicolor ECL from a nanoluminophore was observed for the first time in an aqueous solution. It opens a new research area of multicolor ECL of nanoluminophores, which is of great importance in ECL field from fundamental studies to practical applications.

Acridinium Ester-Functionalized Carbon Nanomaterials: General Synthesis Strategy and Outstanding Chemiluminescence.

In this work, three different kinds of acridinium ester (AE)-functionalized carbon nanomaterials, including AE-functionalized carbon nanoparticles (AE-CNPs), AE-functionalized graphene oxide (AE-GO), and AE-functionalized multiwalled carbon nanotubes (AE-MCNTs), were synthesized for the first time via a simple, general, and noncovalent strategy. AE molecules were assembled on the surface of carbon nanomaterials by electrostatic interaction, π-π stacking interaction, and amide bond. The synthesized AE-CNPs, AE-GO, and AE-MCNTs with 5.0 × 10(-8) mol·L(-1) of synthetic AE concentration, which was very low compared with other chemiluminescence (CL) reagents such as luminol, N-(aminobutyl)-N-(ethylisoluminol), and lucigenin at the concentration of 3.3 × 10(-4) to 5.0 × 10(-6) mol·L(-1) used for the synthesis of CL-functionalized nanomaterials, exhibited outstanding CL activity and good stability. It was found that carbon nanomaterials as nanosized platforms could efficiently immobilize AE molecules and facilitate the formation of OH(•) and O2(•-), leading to strong light emission. Moreover, the CL intensity of AE-GO was the highest, which was about 8.7 and 3.7 times higher than that of AE-CNPs and AE-MCNTs, respectively. This mainly resulted from a difference in the amount of adsorbed AE molecules on the surface of different carbon nanomaterials. Additionally, the prepared AE-CNPs demonstrated excitation-dependent fluorescence property and good fluorescence stability against photobleaching. On the basis of the excellent CL and special fluorescence properties of AE-CNPs, a dual-mode array strategy has been proposed for the first time and seven kinds of transition-metal ions could be successfully discriminated.

Highly Chemiluminescent Graphene Oxide Hybrids Bifunctionalized by N-(Aminobutyl)-N-(Ethylisoluminol)/Horseradish Peroxidase and Sensitive Sensing of Hydrogen Peroxide.

N-aminobutyl-N-ethylisoluminol and horseradish peroxidase bifunctionalized graphene oxide hybrids (ABEI-GO@HRP) were prepared through a facile and green strategy for the first time. The hybrids exhibited excellent chemiluminescence (CL) activity over a wide range of pH from 6.1 to 13.0 when reacted with H2O2, whereas ABEI functionalized GO had no CL emission at neutral pH and showed more than 2 orders of magnitude lower CL intensity than ABEI-GO@HRP at pH 13.0. Such strong CL emission from ABEI-GO@HRP was probably due to that HRP and GO facilitated the formation of O2(•-), - CO4(•2-), HO(•), and π-C═C(•) in the CL reaction, and GO as a reaction interface promoted the electron transfer of the radical-involved reaction. By virtue of ABEI-GO@HRP as a platform, an ultrasensitive, selective, and reagentless CL sensor was developed for H2O2 detection. The CL sensor exhibited a detection limit of 47 fM at physiological pH, which was more than 2 orders of magnitude lower than previously reported methods. This work reveals that bifunctionalization of GO by ABEI and HRP leads to excellent CL feature and enzyme selectivity, which can be used as an ideal platform for developing novel analytical methods.

Sensitive immunosensor for N-terminal pro-brain natriuretic peptide based on N-(aminobutyl)-N-(ethylisoluminol)-functionalized gold nanodots/multiwalled carbon nanotube electrochemiluminescence nanointerface.

A novel electrochemiluminescence (ECL) immunosensor was developed for the determination of N-terminal pro-brain natriuretic peptide (NT-proBNP) by using N-(aminobutyl)-N-(ethylisoluminol) (ABEI)-functionalized gold nanodots/chitosan/multiwalled carbon nanotubes (ABEI/GNDs/chitosan/COOH-MWCNTs) hybrid as nanointerface. First, ABEI/GNDs/chitosan/COOH-MWCNTs hybrid nanomaterials were grafted onto the surface of ITO electrode via the film-forming property of hybrid nanomaterials. The anti-NT-proBNP antibody was connected to the surface of modified electrode by virtue of amide reaction via glutaraldehyde. The obtained sensing platform showed strong and stable ECL signal. When NT-proBNP was captured by its antibody immobilized on the sensing platform via immunoreaction, the ECL intensity decreased. Direct ECL signal changes were used for the determination of NT-proBNP. The present ECL immunosensor demonstrated a quite wide linear range of 0.01-100 pg/mL. The achieved low detection limit of 3.86 fg/mL was about 3 orders of magnitude lower than that obtained with electrochemistry method reported previously. Because of the simple and fast analysis, high sensitivity and selectivity, and stable and reliable response, the present immunosensor has been successfully applied to quantify NT-proBNP in practical plasma samples. The success of the sensor in this work also confirms that ABEI/GNDs/chitosan/COOH-MWCNTs hybrid is an ideal nanointerface to fabricate a sensing platform. Furthermore, the proposed strategy could be applied in the detection of other clinically important biomarkers.

2-[4-(1H-1,2,4-Triazol-1-yl)phen-yl]-1H-benzimidazole.

In the title compound, C(15)H(11)N(5), the benzimidazole ring system is nearly planar [maximum deviation = 0.039 (2) Å], and is oriented at a dihedral angle of 28.85 (10)° with respect to the benzene ring; the dihedral angle between the triazole and benzene rings is 17.30 (15)°. In the crystal N-H⋯N hydrogen bonds link the mol-ecules into chains. Weak C-H⋯N inter-actions are also present.