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Plasmonic catalytic reactions of molecules with single amine or nitro groups have been investigated in recent years. However, plasmonic catalysis of molecules with multiple amine and/or nitro groups is still unknown. In this paper, plasmon-driven catalytic reactions of 4,4'-dinitroazobenzene (DNAB), 4,4'-diaminoazobenzene (DAAB) and 4-nitro-4'-aminoazobenzene (NAAB) are investigated using electrochemical surface-enhanced Raman scattering (SERS) spectroscopy. The results reveal that a plasmon-driven reduction reaction occurred for DNAB and NAAB in which the NO2 group was reduced to NH2, while the plasmon-driven oxidation reaction of NH2 did not occur. This result demonstrates that plasmon-driven reduction reactions are much easier than plasmon-driven oxidization reactions in electrochemical environments. The molecular resonance may also play an important role in plasmon-driven catalytic reactions. These findings provide us with a deeper understanding of plasmon-driven catalytic reactions. [ABSTRACT FROM AUTHOR]

Two luminescent dibenzo[ b,d ]thiophene 5,5-dioxide derivatives combined with 9,9-dimethyl-9,10-dihydroacridine were synthesized and the appearance of thermally activated delayed fluorescence was confirmed. Both 3,7- and 2,8-bis(9,9-dimethyl-9,10-dihydroacridine)dibenzo[ b,d ]thiophene 5,5-dioxide ( 3ASOA ) and ( 4ASOA ) showed prompt and delayed fluorescence with high total photoluminescence (PL) quantum efficiencies of 72% and 88% in their doped films, respectively. The maximum external electroluminescence (EL) efficiencies of 13.8% in 4ASOA and 10.4% in 3ASOA were obtained. Further, 4ASOA showed slightly relaxed rolloff behavior, indicating that 2,8-substitution of the donors appreciably improved both PL and EL characteristics. [ABSTRACT FROM AUTHOR]

A facile electrochemiluminescence (ECL) sensing platform for the sensitive analysis of sophoridine was constructed using Ru(bpy) 3 2+ /carbon quantum dots – polyvinyl alcohol composite film as modifier. The carbon quantum dots (CQDs) which have the ability to enhance the ECL intensity were synthesized through a simple hydrothermal method. As Ru(bpy) 3 2+ was entrapped in the polyvinyl alcohol (PVA), it was beneficial to immobilize Ru(bpy) 3 2+ efficiently on the GCE surface, and therefore a stable ECL signal could be obtained. In addition, the ECL response on the Ru(bpy) 3 2+ /CQDs/PVA composite system was greatly enhanced by sophoridine. Single-factor was applied to optimize the measurement conditions. The fabricated sophoridine sensor exhibited a well-proportional correlation between ECL intensity and the logarithm of sophoridine concentration in the range of 1.0 × 10 −10 –1.0 × 10 −5 M, and the detection limit was 5.0 × 10 −11 M (S/N = 3). Moreover, the detection of sophoridine in blood serum was successfully accomplished and a desirable result by using the ECL sensing system was achieved, which indicated that the fabricated ECL sensor has potential value in sophoridine monitoring in practical samples. [ABSTRACT FROM AUTHOR]

Open-ended piles have been widely adopted in both offshore and onshore geotechnical engineering projects. However, the influence mechanism of pile driving methods on the penetration characteristics of the open-ended piles is not clear. Therefore, this paper presents simulations of an open-ended pile penetrating through a silt layer to a fine sand bearing stratum using static and dynamic driving methods respectively in a series of indoor model tests. Properties including pile sinking resistance, pile end resistance, pile side friction resistance, pile load transfer law and soil plug formation during penetration are analyzed. The results show that the PLR value of the hammered pile is always greater than that of the static pressure pile in the stable sinking stage, while the IFR value of the latter in the sand layer is significantly higher than that of the former. The resistance of the hammered pile under the same penetration depth is less than that of the static pressure pile and increases sharply when entering the holding layer. In addition, the final pile driving resistance of the hammering method is 66.68% of the static pressure pile driving resistance, and the pile end resistance from the static pressure method and hammering method account for 75.4% and 77.6% of the total resistance respectively In the choice of construction method, the static pressure method is more suitable for silty soil, and the hammering method can show its advantages in fine sand formation. • Model tests to simulate penetration of an open-ended pile using both dynamic and static methods. • Hammering method causes greater height of soil plug of the open-ended pile • PLR values are around 21.38% and 32.77% for static and hammering method, respectively. • Impact of hammer driving will disturb the soil around the pile. • Static method is suitable for silt while the hammering method shows its advantages in fine sand. [ABSTRACT FROM AUTHOR]

Background: Tuberculosis infection is a major complication of silicosis, but there is no study on whether silicosis can affect the sensitivity of QuantiFERON-TB Gold In-Tube (QFT-GIT) assays. This study will analyze the relationship between silicosis and QFT-GIT, determine the main factor of the QFT-GIT sensitivity decrease in silicosis and explore the methods to increase the sensitivity. Methods: Silicosis patients with positive tubercle bacillus cultures were collected. The QFT-GIT, flow cytometry and blocking antibodies were used. Results: The sensitivity of QFT-GIT in silicosis patients (58.46%) was significantly decreased and the expression of PD-1 on T cells and CD56+NK cells in pulmonary tuberculosis combined with silicosis were higher than normal tuberculosis patients and silicosis only patients. Further analysis found that the ratio of PD-1+CD4+T and IFN-γwere negatively correlated and blockaded the PD-1 pathway with antibodies can restore the sensitivity of QFT-GIT in silicosis. Conclusions: This is the first study to analyze the relationship between immune exhaustion and QFT-GIT in silicosis and found that the sensitivity of QFT-GIT was decreased by the expression of PD-1 on lymphocytes. Antibody blocking experiments increased the expression of IFN-γ and provided a new method to improve the sensitivity of QFT in silicosis. The study also found that silicosis can increase PD-1 expression. As PD-1 functions in infectious diseases, it will promote immune exhaustion in silicosis and lead to tuberculosis from latent to active infection. The study provided theoretical evidence for the diagnosis and immunotherapy of silicosis complications, and it has great value in clinical diagnostics and treatment. [ABSTRACT FROM AUTHOR]

Currently, electroencephalogram (EEG) is mostly analyzed in a supervised way, which requires EEG labels (e.g., EEG classification). With the ever-increasing amount of unlabeled/mislabeled EEG in neuropsychiatric disorder diagnosis, BCI, and rehabilitation, manually labeling of EEG data is a labor intensive and time-consuming process, and few labs have developed algorithms to analyze EEG in an unsupervised manner (i.e., EEG clustering). In this paper, we propose a cooperative game inspired approach to cluster multi-trial EEG data. The idea is to map multi-trial EEG clustering to the coalition formation in a cooperative game, and then identify cluster center (the EEG trial with highest Shapley value) and assign EEG trials into proper clusters based on their cross correlation-transformed Shapley values. We demonstrate the mapped EEG cooperative game is convex, and it leads to an algorithm for multi-trial EEG clustering named CoGEEGc. The CoGEEGc yields high-quality multi-trial EEG clustering with respect to intra-cluster compactness and inter-cluster scatter. We show that CoGEEGc outperforms 15 state-of-the-art EEG or time series clustering approaches through detailed experimentation on real-world multi-trial EEG datasets. Comparison against 15 methods with four theoretical properties of clustering further illustrates the superiority of CoGEEGc, as it satisfies two properties while other approaches only satisfy one. [ABSTRACT FROM AUTHOR]

Simple Summary: Giardia duodenalis is a world-widely distribution intestinal protozoan parasite that can infect human and a broad range of mammals. It can cause a number of clinical symptoms including diarrhoea, abdominal pain, vomiting, severe dehydration and anemia etc. in animals and humans. Eight genetic assemblages (A to H) have been identified in G. duodenalis based on molecular analysis. In this study, the infection rates and genotypes of G. duodenalis in swine are investigated in Fujian province, southeastern China. G. duodenalis assemblages E was found in pigs in the present study. These results provide epidemiological data for giardiasis prevention, control and public health. Giardia duodenalis, an intestinal parasite, is widely distributed in humans and various animals, such as pigs, cattle and cats. The clinical symptoms of giardiasis are characterized as including abdominal pain, acute or chronic diarrhea, and bloating and weight loss in humans and animals, leading to public and veterinary health problems worldwide. However, the prevalence and genotypes of G. duodenalis in pigs in Fujian Province, southeastern China, have not been reported. In the present study, 725 fecal samples were collected from six cities (Fuqing, Putian, Nanping, Longyan, Sanming, Zhangzhou) in Fujian Province and analyzed for G. duodenalis prevalence and genotypes using nested PCR targeting the beta-giardin (bg), glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi) genes. The results shown that total occurrence rate of G. duodenalis was 26.9% (195/725) in pigs, with significant differences in the prevalence among different regions (χ2 = 86.508, p < 0.05) and groups (χ2 = 12.748, p < 0.05). 195, 11 and 6 samples were detected at the bg, tpi and gdh loci, respectively. Each one belonged to a subtype of assemblage E and was analyzed using sequences obtained in this study. Based on phylogenetic analyses of sequences from the three genetic loci, only one MLG E1 was found. The results indicated that pigs may present a potential zoonotic risk of spreading G. duodenalis infection from animals to humans in this area. The findings of the present study also provide basic data for the prevention and control of G. duodenalis infection in pigs and humans in China. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ag/Fe-Ti spinel presented higher than 90% Hg0 capture efficiency at 250 °C. • H 2 S was an effective syngas component responsible for Hg0 removal. • Ag enhanced the Hg0 removal performance at 250 °C without sulfur poisoning. • Hg0 removal over Ag/Fe-Ti spinel followed the Langmuir-Hinshelwood mechanism. • HgS and surface sulfur were formed on the surface of spent Ag/Fe-Ti spinel. A series of Ag doping Fe-Ti spinel sorbents (Ag/Fe-Ti spinel) were synthesized using co-precipitation and impregnation methods and employed to remove elemental mercury (Hg0) from syngas at high temperatures (200–350 °C). The role of H 2 S on Hg0 elimination over Ag/Fe-Ti spinel and the Hg0 removal mechanism were systematically investigated by experimental and theoretical methods. N 2 adsorption–desorption, SEM-EDS, XRD, H 2 -TPR and XPS were used to characterize the physicochemical properties of samples. The synthesized Ag/Fe-Ti spinel was tested on a fixed-bed reactor for Hg0 removal from the simulated syngas and showed an average mercury removal efficiency above 90 % at 250 °C. Loading Ag effectively enhanced Hg0 removal activity in high-temperature syngas by generating Ag-Hg alloy via the amalgamation reaction. H 2 S played the most important role in mercury removal, by adsorbing Hg0 on Ag/Fe-Ti spinel sorbent surface to form active sulfur species. H 2 S-pretreatment experiments indicated that the reaction of H 2 S and Hg0 occurred via the Langmuir-Hinshelwood mechanism. Stability and cyclic regeneration experiments indicated that the Ag/Fe-Ti spinel had good regeneration performance and reusability. Density functional theory (DFT) calculation was performed to elucidate that strong chemisorption for H 2 S and HgS occurred over the Ag/Fe-Ti spinel surface with adsorption energies of −300.35 kJ/mol and −408.12 kJ/mol, respectively. XPS and DFT calculations demonstrated the Hg0 removal mechanism, which the chemisorbed Hg0 reacted with active sulfur species to generated surface-bound HgS. Both XPS and Hg0-TPD analysis certified the presence of HgS and elemental S on the surface of spent Ag/Fe-Ti spinel. [ABSTRACT FROM AUTHOR]

The authors demonstrate a simple but effective way to manage the exciton, reduce the efficiency roll-off, enhance the color stability and improve the lifetime of hybrid white organic light-emitting diodes simultaneously. Red and green phosphorescent emission layers (EMLs) are connected by a mixed fluorescent blue-emitting layer (MBL), which is composed of two self-host fluorescent materials of N,N′-di-1-naphthalenyl- N,N′-diphenyl-[1,1′:4′,1″:4″,1″′-quaterphenyl]-4,4′″-diamine and bis[2-(2-hydroxyphenyl)-pyridine]beryllium. By adjusting the mixture ratio and the thickness of MBL, the intensity of blue and green emissions can be tuned independently. A maximum power efficiency of 41.1 lm W−1 and external quantum efficiency of 15.8% is obtained without any out-coupling schemes or doping strategies. In addition, the device shows a stable electroluminescence spectrum with Commission International de L'Eclairage coordinates of (0.47, 0.43) in the practical range of 1000-5000 cd m−2. Furthermore, the fuzzy interfaces between MBL and phosphorescent EMLs, and the wide distribution of charges and excitons, result in four times prolonged device lifetime. [ABSTRACT FROM AUTHOR]

Two novel spiro-based host materials, namely 3-(9,9′-spirobi[fluoren]-6-yl)-9-phenyl-9 H -carbazole ( SF3Cz1) and 9-(3-(9,9′-spirobi[fluoren]-6-yl)phenyl)-9 H -carbazole ( SF3Cz2) were designed and synthesized. Due to the meta -linkage of spirobifluorene backbone, both SF3Cz1 and SF3Cz2 possess triplet energies over 2.70 eV, indicating they could serve as suitable hosts for blue and even white phosphorescent organic light-emitting diodes (PHOLEDs). The fabricated bis (4,6-(difluorophenyl)-pyridinato -N,C′)picolinate (FIrpic) based PHOLEDs hosted by SF3Cz1 and SF3Cz2 exhibited excellent performance with maximum external quantum efficiencies (EQEs) of 18.1% and 19.7%, respectively. Two-color warm white PHOLEDs fabricated by utilizing SF3Cz1 and SF3Cz2 as hosts also achieved high EQEs and low efficiency roll-offs. The results demonstrate that SF3Cz1 and SF3Cz2 are promising hosts for blue and white PHOLEDs. [ABSTRACT FROM AUTHOR]

A correction to the article "Determination of Hydrogen Peroxide Based on Calcined Layered Double Hydroxide-Modified Glassy Carbon Electrode in Flavored Beverages" that was published online on December 3, 2011.

We demonstrate the construction of an aggregation-induced electrochemiluminescent (AIECL) sensor for glutathione (GSH) assay by integrating an aminal-linked covalent organic framework (A-COF) with manganese dioxide (MnO2) nanosheets. The AIECL of the A-COF is quenched by the MnO2 nanosheets via electrochemiluminescent resonance energy transfer (ERET) from the excited A-COF to MnO2. The presence of GSH can reduce the MnO2 nanosheets into Mn2+, restoring the AIECL emission of the A-COF. This AIECL sensor has the characteristics of fast response, high sensitivity, and good selectivity toward GSH, and it can accurately measure GSH in human serum. [ABSTRACT FROM AUTHOR]

A correction to the article "Whisker Stimulation Enhances Angiogenesis in the Barrel Cortex Following Focal Ischemia in Mice," by Vivian R. Whitaker, Lin Cui, Scott Miller, Shan P. Yu and Ling Wei, that was published in the November 2006 issue is presented.

• A dual-mode biosensor was developed for detection OPPs based on MO@FHO nanozyme. • The MO@FHO nanozyme was used with enhanced catalase-like and oxidase-like activities. • This biosensor can efficiently differentiate OPPs from organochlorine pesticides. • This assay realized the food analysis in the complex biological matrices. Herein, we develop a dual-mode biosensor for photoelectrochemical and colorimetric detection of organophosphate pesticides (OPPs) based on ultrathin-FeOOH-coated MnO 2 (MO@FHO) nanozyme. In this biosensor, OPPs can inhibit the alkaline phosphatase (ALP) activity and hinder the dephosphorylation of l -ascorbic acid-2-phosphate, preventing the decomposition of MO@FHO nanozyme and inducing both a photoelectrochemical (PEC) signal and the colorimetric change. The MO@FHO nanozyme not only possesses an enhanced catalase-like activity to degrade H 2 O 2 for the generation of an improved cathodic photocurrent, but also exhibits an excellent oxidase-like activity to oxidize 3,3,5,5-tetramethylbenzidine with high catalytic efficiency. This biosensor displays a detection limit of 50 pmol/L for the PEC mode and a detection limit of 0.8 nmol/L for the colorimetric mode. Moreover, this biosensor exhibits excellent performance in complex biological matrices, and the smartphone-based visual sensing platform facilitates rapid and sensitive detection of OPPs, holding promising applications in food safety monitoring, and on-site detection. [ABSTRACT FROM AUTHOR]

The reported organic electrochemiluminescence (ECL) luminophors for the detection of various markers often suffer from intermolecular π-π stacking-induced luminophore quenching. Herein, we demonstrate one-pot synthesis of a new aggregation-induced electrochemiluminescence (AIECL) emitter (i.e., TPE@SiO 2 /rGO composite) for sensitive measurement of microcystin-leucine arginine (MC-LR). The TPE@SiO 2 /rGO composite is constructed by embedding the silica-encapsuled 1,1,2,2-tetra(4-carboxylphenyl)ethylene (TPE) in the reduced graphene oxide. In comparison with the monomer TPE, this composite exhibit high luminescence efficiency and strong ECL emission, because the AIECL phenomenon triggered by the spatial confinement effect in the SiO 2 cage induces the restriction of the internal motion and vibration of molecules. Notably, this composite has distinct advantages of easy preparation, simple functionalization, and stable luminescence. Especially, the TPE@SiO 2 /rGO-based ECL-RET system exhibits a high quenching efficiency (Φ ET) of 69.7%. When target MC-LR is present, it triggers DNA strand displacement reaction (SDR), inducing the quenching of the ECL signal of TPE@SiO 2 /rGO composite due to ECL resonance energy transfer between TPE@SiO 2 /rGO composite and methylene blue (MB). The proposed biosensor enables highly sensitive, low-cost, and robust measurement of MC-LR with a large dynamic range of 7 orders of magnitude and a detection limit of 3.78 fg/mL, and it displays excellent detection performance in complex biological matrices, holding potential applications in food safety and water monitoring. We demonstrate the synthesis of silica-encapsulated tetraphenylethylene with aggregation-induced electrochemiluminescence resonance energy transfer for sensitively sensing microcystin-LR. [Display omitted] • We demonstrate one-pot synthesis of a new AIECL emitter with AIECL-RET. • The emitter exhibits high luminescence efficiency and strong ECL emission. • The AIECL-RET system possesses a high quenching efficiency of 69.7%. • This biosensor can sensitively detect microcystin-leucine arginine. • It exhibits a detection limit of 3.78 fg/mL and a wide linear range. [ABSTRACT FROM AUTHOR]

• A novel open compression-absorption heat pump system model was studied. • The key parameters were optimized by energy analysis and exergy analysis. • Compression can enhance the effect of condensation and solution dehumidification. • The COP of the system was 1.59, with 82.2% water recovery and 86.4% heat recovery. • The exergy efficiency of regenerator is the lowest in the heat pump system. Realizing the recovery of latent heat and moisture from low-temperature and high-humidity flue gas (LHFG) can effectively improve energy efficiency and reduce carbon emissions. A novel open compression absorption heat pump (OCAHP) is proposed to fulfill the demand for flue gas water and heat recovery. In this paper, Aspen Plus is used to establish a model, and the coefficient of performance (COP), water and heat recovery rate are evaluated to investigate the effects of the gas inlet temperature, compression ratio, liquid-to-gas ratio, and absorber inlet solution temperature parameters on water and heat recovery performance for OCAHP. The parameters are optimized, and exergy analysis is carried out. The simulation results show that wet flue gas with successive adiabatic compression and CaCl 2 /H 2 O solution absorption has significant water and heat recovery performance. The results also prove that the water recovery efficiency of the OCAHP system is 82.4% at a compression ratio of 1.4, which is approximately 12.3% higher than that of the conventional open absorption heat pump (OAHP) system, and it is suitable for wet flue gas with a higher saturation temperature. Furthermore, exergy analysis shows that the exergy efficiency of the OCAHP system is higher than that of the conventional OAHP system, while the exergy loss is mainly concentrated in the regenerator heating process and the solution-water heat exchanger. [ABSTRACT FROM AUTHOR]

An experimental platform was established to study the distribution and motion characteristics of fine particles in an electrostatic precipitator (ESP) with electric, temperature, and particle concentration, multi-field synergistic effect. The fine particle concentrations were tested by measuring reformed ELPI in real-time. For discussion, motion characteristics of fine particles such as trajectory, deposition, re-entrainment and water flushing were analyzed by mechanical modeling, listing up every force acting on the fine particles. The results show that the type and the force order of magnitude of the particle will change correspondingly in different states. The synergistic state is beneficial to the removal of particles in the whole range, especially the particle size of 0.1⁓1 μm, and the maximum removal rate is increased by 15% compared with the wet state. The increasing of Fy (liquid bridge), Fc (particle concentration gradient) and Fth (thermophoresis). increase the removal efficiency of fine particles in synergistic state. [Display omitted] • The removal efficiency of 0.1-1 μm particles is the most obvious by synergy effect. • The synergistic fields increase the force of near-wall particles towards the wall. • The root reason of high removal efficiency in synergistic: F y , F C and F th increases. • The multi-field synergy provides a new development direction for ESP. [ABSTRACT FROM AUTHOR]

• The combination of limestone-based dual-loop WFGD and oxygen-enriched combustion was proposed. • Main influence factors and reaction mechanism were fully investigated. • Effect of CO 2 concentration on desulfurization process of single-loop and dual-loop WFGD was compared. • Dual-loop WFGD has better adaptability to flue gas desulfurization after oxygen-enriched combustion. Oxygen-enriched combustion is the most promising CO 2 emission reduction technology for coal burning. However, the sharp increase in CO 2 and SO 2 concentrations in flue gas after oxygen-enriched combustion poses a new challenge to the subsequent wet flue gas desulfurization (WFGD) system. In this study, limestone-based dual-loop WFGD technology was used to solve this problem. Using a small dual-loop falling-film WFGD experimental system, the effect of CO 2 concentration on limestone dissolution, SO 2 absorption, SIV oxidation, and CaSO 4 crystallization during limestone-based dual-loop WFGD was investigated in detail and compared with single-loop WFGD. The results show that, although an increase in CO 2 concentration is beneficial to SO 2 absorption in the single-loop WFGD system, it is not conducive to limestone dissolution, SIV oxidation, and CaSO 4 crystallization. Compared with single-loop WFGD, in the low pH region of dual-loop WFGD, increasing the CO 2 concentration can also improve the SO 2 absorption efficiency. However, it had no obvious effect on limestone dissolution, SIV oxidation, and CaSO 4 crystallization. In the high pH region of the dual-loop WFGD, although an increase in CO 2 concentration is not conducive to SO 2 absorption, the SO 2 absorption efficiency is still higher than that of single-loop WFGD. The negative effect of increasing the CO 2 concentration on limestone dissolution, SIV oxidation, and CaSO 4 crystallization can be effectively solved by introducing slurry from the high pH region into the low pH region. Therefore, compared with single-loop WFGD technology, dual-loop WFGD is more suitable for flue gas desulfurization after oxygen-enriched combustion. [ABSTRACT FROM AUTHOR]

A series of novel AIE-active (aggregation-induced emission) molecules, named SAF-2-TriPE, SAF-3-TriPE, and SAF-4-TriPE, were designed and synthesized through facile reaction procedures. We found that incorporation of the spiro-acridine-fluorene (SAF) group, which is famous for its excellent hole-transporting ability and rigid structure, at different substitution positions on the phenyl ring affected the conjugation lengths of these compounds. Consequently, we have obtained molecules with different emission colors and properties without sacrificing good EL (electroluminescence) characteristics. Accordingly, a device that was based on compound SAF-2-TriPE displayed superior EL characteristics: it emitted green light with ηc, max=10.5 cd A−1 and ηext, max=4.22 %, whereas a device that was based on compound SAF-3-TriPE emitted blue-green light with ηc, max=3.9 cd A−1 and ηext, max= 1.71 %. These compounds also displayed different AIE performances: when the fraction of water in the THF solutions of these compounds was increased, we observed a significant improvement in the ΦF of compounds SAF-2-TriPE and SAF-3-TriPE; in contrast, compound SAF-4-TriPE showed an abnormal phenomenon, in that it emitted a strong fluorescence in both pure THF solution and in the aggregated state without a significant change in ΦF. Overall, this systematic study confirmed a relationship between the regioisomerism of the luminophore structure and its AIE activity and the resulting electroluminescent performance in non-doped devices. [ABSTRACT FROM AUTHOR]

A simple and disposable electrochemical immunosensor was developed for sensitive and selective detection of a protein biomarker via target-induced proximity hybridization and electrochemical stripping analysis of silver nanoparticles (AgNPs). The immunosensor was prepared by assembling single-stranded DNA modified gold nanoparticles (ssDNA@AuNPs) on a graphene oxide modified disposable screen-printed carbon electrode (SPCE). In the presence of a target protein and two DNA-labeled antibodies, the proximate complex formed in homogeneous solution could hybridize with the assembled DNA to take away AuNPs, which decreased AuNP-catalyzed deposition of AgNPs on the immunosensor surface, and thus the anodic stripping signal. The proposed method avoided the interference of dissolved oxygen. Using the carcinoembryonic antigen (CEA) as a model analyte, this method showed a linear range of four magnitude orders with a detection limit down to 3.9 pg mL−1. The electrochemical immunosensor possessed preparation convenience, good stability and high sensitivity, and could be extended to sensitive biosensing of other analytes, showing potential application in point-of-care testing. [ABSTRACT FROM AUTHOR]

Inorganic–organic hybrid WO x –ethylenediamine (WO x –EDA) nanowires with high surface-to-volume ratio and abundant amino groups were synthesized for selective and sensitive electrochemical determination of Pb 2 + . The WO x –EDA nanowires possessed a uniform lamellar mesostructure and could disperse evenly in Nafion solution for preparation of WO x –EDA modified electrode with good reproducibility. The modified electrode showed selective response toward Pb 2 + due to the chelating between amino groups and Pb 2 + . The electrochemical characterization and detection of bound Pb 2 + were performed by square wave anodic stripping voltammetry. Under optimized conditions, the WO x –EDA-based sensor could detect Pb 2 + directly from 0.01 to 10 μM with a detection of limit down to 3.2 nM. The proposed sensor with WO x –EDA hybrid nanowires exhibited good selectivity and sensitivity, and acceptable stability and reproducibility, showing promising practical application in Pb 2 + determination. [ABSTRACT FROM AUTHOR]

The healing of severe skin injury is a complicated process and the development of hydrogel dressing with antibacterial and stimuli responsive abilities is necessary. Recently, reduced graphene oxide (RGO) has been widely used in hydrogel dressings due to its good conductivity and photothermal effects. However, there still exist some problems in the fabrication of RGO‐modified hydrogels, especially in the green preparation and dispersion process of RGO. In this work, macromolecular carboxymethyl chitosan (CMCS) is chosen as the reducing agent for the green preparation of RGO. Hydrogels with antibacterial and stimulus‐responsive properties are constructed via Schiff base condensation between CMCS and oxidized pectin (OP). Over 95% cell viability is observed, which is critical for medical applications. RGO endows the hydrogels with relatively good conductivity, self‐healing properties, and mechanical strength. The diameters of bacteriostasis circle of the hydrogel for Escherichia coli and Staphylococcus aureus increase by 0.2 and 0.8 cm respectively after exposure to NIR for 5 min, resulting from the photothermal antibacterial properties of the hydrogel provided by RGO. This study provides guidance for the design and application of multifunctional wound dressing. [ABSTRACT FROM AUTHOR]

Background In Singapore, quarantine of all close contacts with entry and exit polymerase chain reaction testing enabled evaluation of the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination and pediatric age on transmission of the Delta variant. Methods This retrospective cohort study included all household close contacts between 1 March 2021 and 31 August 2021. Results Among 8470 Delta variant-exposed contacts linked to 2583 indices, full-vaccination of the index with BNT162b2 or mRNA-1273 was associated with reduction in acquisition by contacts (adjusted odds ratio [aOR], 0.56; 95% robust confidence interval [RCI],.44–.71 and aOR, 0.51; 95% RCI,.27–.96, respectively). Compared with young adults (aged 18–29 years), children (aged 0–11 years) were significantly more likely to transmit (aOR, 2.37; 95% RCI, 1.57–3.60) and acquire (aOR, 1.43; 95% RCI, 1.07–1.93) infection, vaccination considered. Longer duration from vaccination completion among contacts was associated with decline in protection against acquisition (first-month aOR, 0.42; 95% RCI,.33–.55; fifth-month aOR, 0.84; 95% RCI,.55–.98; P <.0001 for trend) and symptomatic disease (first-month aOR, 0.30; 95% RCI,.23–.41; fifth-month aOR, 0.62; 95% RCI,.38–1.02; P <.0001 for trend). Contacts immunized with mRNA-1273 had significant reduction in acquisition (aOR, 0.73; 95% RCI,.58–.91) compared with BNT162b2. Conclusions Among household close contacts, vaccination prevented onward SARS-CoV-2 transmission and there was in-creased risk of SARS-CoV-2 acquisition and transmission among children compared with young adults. Time after completion of vaccination and vaccine type affected SARS-CoV-2 acquisition. [ABSTRACT FROM AUTHOR]

Background The impact of SARS-CoV-2 variants of concern (VOCs) on disease severity is unclear. In this retrospective study, we compared the outcomes of patients infected with B.1.1.7, B.1.351, and B.1.617.2 with wild-type strains from early 2020. Methods National surveillance data from January to May 2021 were obtained and outcomes in relation to VOCs were explored. Detailed patient-level data from all patients with VOC infection admitted to our center between December 2020 and May 2021 were analyzed. Clinical outcomes were compared with a cohort of 846 patients admitted from January to April 2020. Results A total of 829 patients in Singapore in the study period were infected with these 3 VOCs. After adjusting for age and sex, B.1.617.2 was associated with higher odds of oxygen requirement, intensive care unit admission, or death (adjusted odds ratio [aOR], 4.90; 95% confidence interval [CI]: 1.43-30.78). Of these patients, 157 were admitted to our center. After adjusting for age, sex, comorbidities, and vaccination, the aOR for pneumonia with B.1.617.2 was 1.88 (95% CI:.95-3.76) compared with wild-type. These differences were not seen with B.1.1.7 and B.1.351. Vaccination status was associated with decreased severity. B.1.617.2 was associated with significantly lower polymerase chain reaction cycle threshold (Ct) values and longer duration of Ct value ≤30 (median duration 18 days for B.1.617.2, 13 days for wild-type). Conclusions B.1.617.2 was associated with increased severity of illness, and with lower Ct values and longer viral shedding. These findings provide impetus for the rapid implementation of vaccination programs. [ABSTRACT FROM AUTHOR]

The hyperspectral feature extraction technique is one of the most popular topics in the remote sensing community. However, most hyperspectral feature extraction methods are based on region-based local information descriptors while neglecting the correlation and dependencies of different homogeneous regions. To alleviate this issue, this paper proposes a multi-view structural feature extraction method to furnish a complete characterization for spectral–spatial structures of different objects, which mainly is made up of the following key steps. First, the spectral number of the original image is reduced with the minimum noise fraction (MNF) method, and a relative total variation is exploited to extract the local structural feature from the dimension reduced data. Then, with the help of a superpixel segmentation technique, the nonlocal structural features from intra-view and inter-view are constructed by considering the intra- and inter-similarities of superpixels. Finally, the local and nonlocal structural features are merged together to form the final image features for classification. Experiments on several real hyperspectral datasets indicate that the proposed method outperforms other state-of-the-art classification methods in terms of visual performance and objective results, especially when the number of training set is limited. [ABSTRACT FROM AUTHOR]

A new bipolar host material (PBCz-PO) consisting a phosphinic amide is developed to show a resonance effect. It possesses quite high triplet energy (2.76 eV), and this high triplet energy make it suitable to be blue host in phosphorescent organic light-emitting diodes (PHOLEDs). The device with PBCz-PO as a host and FIrpic as a dopant achieved a maximum current efficiency ( η c ) of 31.5 cd/A, a maximum power efficiency ( η p ) of 31.0 lm/W and a maximum external quantum efficiency (EQE) of 13.4% as well as low driving voltage. [ABSTRACT FROM AUTHOR]

Two new 10-phenyl-9,10-dihydroacridine derivatives attached by dibenzothiophene (DBT) and dibenzofuran (DBF) were synthesized. The influence of the substituents of these materials was studied by theoretical calculations (DFT calculation) and experimental measurements. Owing to the twisted N-phenyl ring, both molecules possess sufficiently high triplet energies and are suitable as hosts for phosphorescent organic light-emitting diodes. To evaluate the electroluminescent (EL) performance of these materials, FIrpic-based blue PHOLEDs and two-color white PHOLEDs (FIrpic and PO-01 as the dopants) were fabricated using the common device structures. High external quantum efficiencies (EQE) of 21.1 % and 20.9 % for FIrpic-based blue PHOLEDs were achieved by FPhAc and TPhAc, respectively. The white device based on the host FPhAc achieved a higher performance, with a maximum EQE of 24.7 % than the device with TPhAc as host material. [ABSTRACT FROM AUTHOR]

A numerical tool is developed in the framework of the Discrete-Module-Beam method to analyze hydroelasticity of very large floating structures (VLFS) such as floating offshore photovoltaic platforms (FOPV). The proposed method utilizes finite element theory to perform structural analysis. The 3D potential flow theory is used to perform a hydrodynamic analysis after macro-submodule division. For the structural analysis part, the platform is divided into macro-submodules and each macro-submodule is represented by a beam, which is then further discretized into micro beam elements with the nodes categorized into three groups, that is, the lumped mass, the boundary nodes and the inner nodes. Derivation of the lumped-mass stiffness matrix and recovery of the displacement distribution are given. Procedures to deal with interconnections, complex boundary conditions and unsteady loads are elaborated. Good agreement is obtained in different loading scenarios to the numerical and experimental results. • The finite element theory is introduced into the discrete-module-beam method. • Hydroelasticity of a pontoon type VLFS is investigated. • Effects of interconnections and boundary conditions are explored. [ABSTRACT FROM AUTHOR]

• MEA-CS has good CO 2 capture performance for coal-fired flue gas without thermal regeneration. • Using CS can reduce operating costs and promote solid waste high-value utilization. • Main loss of MEA is physical loss and can be reduced by low MEA concentration. • MEA has good synergistic effect with CS compared to other amines. Thermal amine regeneration CO 2 capture with amines is the most widely used technology. However, this method suffers from high energy consumption and amine losses, and captured CO 2 storage safety limits its further application. To achieve CO 2 capture and utilization with low energy consumption and high efficiency, this study constructed a CO 2 synergistic absorption-mineralization reaction system based on monoethanolamine (MEA)-carbide slag (CS). The CO 2 capture process and its effects are analyzed. The circulating absorption-mineralization activity of the coal-fired flue gas of the MEA-CS is studied. Compared with other technologies, it has good CO 2 coupled absorption-mineralization performance for coal-fired flue gas and promotes the green utilization of CS and produces high-value CaCO 3 products. CS can promote MEA recycling, which determines the CO 2 absorption. MEA determines the CO 2 absorption-mineralization rate; however, the CO 2 absorption-mineralization rate does not change when MEA is > 0.1 mol/L. MEA has the best synergistic effect with CS compared to the other amines. After five rounds of experiments, the CO 2 capture efficiency of MEA-CS decreases by approximately 3 %. MEA loss leads to a decrease in the CO 2 capture efficiency, which includes physical and chemical losses. The main loss of MEA is the physical loss, which can be reduced by low MEA concentrations. The CO 2 absorption-mineralization product is CaCO 3. Compared with other CO 2 capture technologies, the regeneration energy consumption is lower, and the existence of captured CO 2 in solid form avoids the problem of CO 2 storage and utilization. [ABSTRACT FROM AUTHOR]

TheC3 meta-position of fluorene is utilized to construct high-tripletenergy compounds. Incorporating a spiroacridine structure, two newhost materials SAFDPA and SAFCz were facilely obtained. Their thermaland photophysical properties are fully investigated. The best efficienciesof 19.4%/21.5% of blue/white devices are achieved by SAFCz. [ABSTRACT FROM AUTHOR]

Background noise and reverberation interference are the main interference sources in the sonar target detection. How to reduce their effects on sonar performance effectively has been a focus of underwater acoustic signal processing. According to Voherra series theory, a nonlinear dynamic model of underwater acoustic signal is established to realize the noise reduction of background noise and the suppression of reverberation interference by predicting the underwater acoustic signal. The direct and iterative methods are used for the one-step and multi-step predictions of the underwater acoustic signal, respectively, by using the two-order Voherra adaptive filter and the singular value decomposition adaptive algorithm. The simulation results show that the iterative method has higher prediction performance and effective muhi-step prediction capability. [ABSTRACT FROM AUTHOR]

[Display omitted] • The amine was successfully impregnated on the expanded vermiculite support with layered structure. • The influence of amine-carrier interfacial effects on CO 2 adsorption performance was revealed. • The adsorption mechanism of EVMT-50TETA adsorbent were investigated. • DFT calculations elucidated amine volume expansion and amine-support interaction strength. The utilization of inexpensive and efficient amine-functionalized adsorbents has become a research hotspot in post-combustion capture technology. Meanwhile, the structure of the support and the selection of organic amines are the primary considerations affecting the CO 2 adsorption performance. Herein, the novel solid amine adsorbent materials with amine-support interfacial effect were successfully synthesized in this study by loading four organic amines (TETA, TEPA, PEHA, and PEI) onto expanded vermiculite (EVMT) support with the layered structure. The results indicated that EVMT-50TETA exhibited superior CO 2 adsorption capacity (132.5 mg/g) along with effective regeneration capability. This was attributed to the unique layered structure of EVMT that facilitates the dispersion of TETA on its surface or between layers as well as the formation of hydrogen bonds between surface functional groups (–OH) and amines to enhance the amine-support interfacial interaction. Furthermore, the minimal volume expansion of TETA during CO 2 adsorption enables improved diffusion of CO 2 in channels and enhanced accessibility to active sites. DFT calculations show higher binding energies and faster CO 2 adsorption-diffusion rates between TETA and EVMT support. In situ DRIFTS experiments revealed that the process of CO 2 adsorption followed the zwitterion mechanism, in which the zwitterion can be reversibly deprotonated to form ammonium carbamate and carbamic acid. This study provides comprehensive insights into the supports and amines interfacial effects through systematic investigation, offering both simplified synthesis strategies and profound theoretical support for studying solid amine adsorbents. [ABSTRACT FROM AUTHOR]

[Display omitted] • The amine-support matching approach was proposed to develop CO 2 absorbent. • TETA has the highest matching degree to X-5 compared with other amines. • Amine-support matching approach controls dispersion patterns of amines in the support. • DFT calculations were performed to evaluate the CO 2 adsorption strength of the four amines. • Kinetic modeling and adsorption mechanism of X-5-30TETA adsorbent were investigated. The solid amine adsorbents are potential candidates as materials for post-combustion capture technologies. The type of organic amine and porous material are the key factors influencing the amine-based solid adsorbent performance. Furthermore, there has been relatively little research on the matching mechanism between organic amines and porous materials. This study aims to investigate the effect of the degree of matching between different organic amines and porous materials (X-5 resin) on the performance of CO 2 capture. The results indicated that 30 wt% TETA was the highest matching degree with X-5 and had the maximum CO 2 adsorption of 205.48 mg/g at 30 ℃. The matching degree between the four amines and the X-5 resin followed TETA > TEPA > PEHA > PEI. Since TETA has the simplest molecular structure, it can be conveniently dispersed in the X-5 pores, which not only significantly improves the utilization of active sites but also prevents the phenomena of agglomeration or sintering. Meanwhile, X-5-30TETA has the highest adsorption energy E ads (−85.22 kJ/mol) and the smallest spatial potential resistance, decreasing the mass transfer resistance effectively, thus further increasing the adsorption capacity. Furthermore, the adsorption kinetics results showed that the Avrami model can relatively accurately predict the experimental results of X-5-TPHI CO 2 adsorption. Finally, the in situ DRIFTS indicated that the CO 2 adsorption reaction over X-5-30TETA followed predominantly an amphipathic centipede mechanism. This work provides a new idea for the investigation of the matching mechanism between organic amines and porous materials. [ABSTRACT FROM AUTHOR]

Although clinical antidepressants have varied mechanisms of action, it remains unclear whether they may have a common mechanism underlying their antidepressant effects. We investigated the behavioral effects of five different antidepressants (differing in target, chemical structure, and rate of onset) and their effects on the firing activities of glutamatergic pyramidal neurons in the medial prefrontal cortex (mPFC) using the forced swimming test (FST) and electrophysiological techniques (in vivo). We employed fiber photometry recordings to validate the effects of antidepressants on the firing activity of pyramidal neurons. Additionally, multichannel electrophysiological recordings were conducted in mice exhibiting depressive-like behaviors induced by chronic restraint stress (CRS) to investigate whether antidepressants exert similar effects on pyramidal neurons in depressed mice. Behavioral tests were utilized for evaluating the depression model. We found that fluoxetine, duloxetine, vilazodone, YL-0919, and ketamine all increase the firing activities of glutamatergic pyramidal neurons (at least 57%) while exerting their initial onset of antidepressant effects. Fiber photometry revealed an increase in the calcium activity of pyramidal neurons in the mPFC at the onset of antidepressant effects. Furthermore, a significant reduction was observed in the firing activity of pyramidal neurons in the mPFC of CRS-exposed mice, which was reversed by antidepressants. Taken together, our findings suggested that five pharmacologically distinct classes of antidepressants share the common ability to increase the firing activity of pyramidal neurons, just different time, which might be a rate-limiting step in antidepressants onset. The study contributes to the body of knowledge of the mechanisms underlying antidepressant effects and paves the way for developing rapid-acting antidepressants. • The firing activity of pyramidal neurons was increased at the onset of antidepressant effects. • Antidepressants increased the firing activity of pyramidal neurons in the mPFC at different speeds. • Increasing the firing activity of pyramidal neurons is a common mechanism in the initiation of the antidepressant effect. • The firing activity of pyramidal neurons may help predict the antidepressant effects of novel drugs. [ABSTRACT FROM AUTHOR]

Microcystin-LR (MC-LR) is an algae toxin that poses a serious threat to human health because of its multiorgan toxicity, genotoxicity, and carcinogenicity. Herein, we develop an electrochemiluminescent (ECL) immunosensor for MC-LR detection on the basis of aggregation-induced ECL (AIECL)-assisted self-enhancement strategy. The probe used in this assay is prepared by simultaneously encapsulating AIEgens (namely 1,1,2,2-tetra(4-carboxylbiphenyl)ethylene (H 4 TCBPE) and its coreactant 2-(dibutylamino)ethanol (DBAE)) into silica to form ternary H 4 TCBPE@SiO 2 -DBAE nanoparticles. DBAE can function as a catalyzer to accelerate the in situ formation of SiO 2 matrix and an intracoreactant to react with H 4 TCBPE for the generation of an intense ECL emission as a result of shortened electron transfer pathway and decreased energy loss. We further prepare a biocompatible and electroactive Ti 3 C 2 T x /MoS 2 /Au hybrid that acts as the immuosensing substrate to accelerate interfacial electron transfer and conjugate the captured antibody (Ab 1). Both Ab 1 -coated Ti 3 C 2 T x /MoS 2 /Au and antibody (Ab 2)-labeled H 4 TCBPE@SiO 2 -DBAE can interact with target MC-LR to obtain a sandwich immunosensor. This immunosensor enables quantitative detection of MC-LR antigen with a detection limit of 31 fg/mL and a broad linear range from 50 fg/mL to 10 ng/mL. The proposed strategy opens up a new avenue to fabricating new self-enhanced ECL emitters for sensitive monitoring of environmental microcystins. • We develop an electrochemiluminescent immunosensor for microcystin-LR assay. • This assay is based on aggregation-induced electrochemiluminescence (AIECL). • We prepare silica nanoparticles with incorporation of AIEgen and coreactant. • This immunosensor exhibits high sensitivity with a broad linear range. • This immunosensor can sensitively monitor environmental microcystins. [ABSTRACT FROM AUTHOR]

Reducible metal-oxide based nanozymes have received much attention in recent years due to their excellent and tunable enzyme-mimicking properties. Herein, porous CeO 2 nanorods supported Pt-based nanozymes with specific content of oxygen vacancy (Ov) were synthesized by combining atomic layer deposition and te following hydrogen activation strategy, among which the Pt/CeO 2 -650R nanozymes with average particle size of 1.6 nm exhibit the optimized peroxidase activity in the typical H 2 O 2 –TMB reaction systems, whose specific activity is 3–fold higher than that of Pt/CeO 2 counterparts. Besides, the reduced nanozymes also present excellent degradation and antibiosis properties. The activity enhancement is ascribed to the Pt–Ov synergy contributing to the stronger capability to generate active radical species. This work affords new insights for in-depth understanding metal–Ov synergy in nanozyme catalysis field. [Display omitted] ● Efficient Pt-CeO 2 nanozymes with controllable size and Ov content were synthesized. ● The significant enhancement of peroxidase activity were achieved by Pt–Ov synergy. ● The optimized nanozymes also present excellent degradation and antibiosis property. ● The underlying nature of Pt–Ov synergy is clearly elucidated. [ABSTRACT FROM AUTHOR]

Significant progress has been made in the application of nanoparticle drug carriers in the treatment of cancer. However, the clearance of nanoparticles by the reticuloendothelial system limits their circulation time and tumor cell targeting, reducing the effectiveness of drug delivery. Herein, we construct a bionic core–shell nanostructure by using a "Trojan horse" strategy. The constructed biotin (bio)-modified red blood cell membrane (RBCm)-coated mesoporous silica nanoparticle (MSN) drug carrier (Bio-RBCm@MSN–DOX) exhibits excellent stability, high efficiency of drug encapsulation, and resistance to elimination by immune cells. Therefore, Bio-RBCm@MSN–DOX is a sustained drug delivery system (SDDS) that prolongs circulation and enhances the effective drug release time. The ability to target HeLa cells increased about 4.64 times and the phagocytic efficiency of macrophages decreased by 2.55 times. The composite core–shell structure developed here can serve as a multifunctional drug carrier system, which can become a novel candidate for "circulating target-therapy" carriers. [ABSTRACT FROM AUTHOR]

Remyelination has to occur to fully regenerate injured spinal cords or brain tissues. A growing body of evidence has suggested that exogenous cell transplantation is one promising strategy to promote remyelination. However, direct injection of neural stem cells or oligodendrocyte progenitor cells (OPCs) to the lesion site may not be an optimal therapeutic strategy due to poor viability and functionality of transplanted cells resulted from the local hostile tissue environment. The overall objective of this study was to engineer an injectable biocompatible hydrogel system as a supportive niche to provide a regeneration permissive microenvironment for transplanted OPCs to survive, functionally differentiate, and remyelinate central nervous system (CNS) lesions. A highly biocompatible hydrogel, based on thiol-functionalized hyaluronic acid and thiolfunctionalized gelatin, which can be crosslinked by poly-(ethylene glycol) diacrylate (PEGDA), was used. These hydrogels were optimized first regarding cell adhesive properties and mechanical properties to best support the growth properties of OPCs in culture. Transplanted OPCs with the hydrogels optimized in vitro exhibited enhanced survival and oligodendrogenic differentiation and were able to remyelinate demyelinated axons inside ethidium bromide (EB) demyelination lesion in adult spinal cord. This study provides a new possible therapeutic approach to treat CNS injuries in which cell therapies may be essential. [ABSTRACT FROM AUTHOR]

Abstract: Aimed at the inherent flaws of stable deterministic error in conventional algorithm using Jerk model, a modified algorithm was proposed. Jerk model and current Jerk model were fused in the improved algorithm. Weak Jerk maneuver was described by using Jerk model and its system noise variance was adjusted by using the relations of position estimation error and acceleration change rate variance. The strong Jerk maneuver was described by using the current Jerk model, and the statistical characteristics of acceleration change rate variance was depicted by using modified Rayleigh distribution. The tracking accuracy for weak Jerk maneuver was improved, and the tracking ability for strong Jerk maneuver was enhanced by introducing fuzzy distribution function and strong track filter. The theoretical analysis and simulation results show that the defect of conventional Jerk model algorithm is overcome by using the improved algorithm, Jerk sudden maneuver with various intensity can be approached adaptively. Under different intensity signal-to-noise ratios and gauging noises, its error is relatively stable and it has better tracking accuracy. [ABSTRACT FROM AUTHOR]

The electrochemical behavior of rutin was investigated in pH 6.0 buffer solution using a glassy carbon electrode coated with graphene nanosheets, chitosan and a poly (amidoamine) dendrimer in pH 6.0 buffer solution. The results indicate that the modified electrode displays electrochemical redox activity towards rutin, and that the oxidation peak current of rutin increases significantly compared to that at other electrodes. The amount of immobilized graphene and dendrimer, pH value, scan rate, accumulation time and accumulation potential were optimized. The kinetic parameters, charge transfer coefficient, transfer electron number, proton transfer number, standard rate constant, were calculated. Under the optimized conditions, the oxidation peak current is proportional to the concentration of rutin in the range between 0.001 and 2.0 μmol L ( R = 0.9991). The detection limit is 0.6 nmol L (at S/N = 3). The electrode exhibits satisfactory selectivity and reproducibility and was applied to the determination of rutin in pharmaceutical preparations, spiked human serum, and traditional Chinese medicine, with recoveries between 97.2 and 104.67%. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: A novel and reliable electrochemical sensor based on PbO2-carbon nanotubes-room temperature ionic liquid (i.e., 1-butyl-3-methylimidazolium hexafluorophosphate, BMIMPF6) composite film modified glassy carbon electrode (GCE) (PbO2–MWNT–RTIL/GCE) was proposed for simultaneous and individual determination of guanine and adenine. The guanine and adenine oxidation responses were monitored by differential pulse voltammetric (DPV) measurement. Compared with the bare electrode, the PbO2–MWNT–RTIL/GCE not only significantly enhanced the oxidation peak currents of guanine and adenine, but also lowered their oxidation overpotentials, suggesting that the synergistic effect of PbO2, MWNT and RTIL could dramatically improve the determining sensitivity of guanine and adenine. The PbO2–MWNT–RTIL/GCE showed good stability, high accumulation efficiency and enhanced electrocatalytic ability for the detection of guanine and adenine. Besides, the modified electrode also exhibited good behaviors in the simultaneous detection of adenine and guanine with the peak separation of 0.29V in 0.1M pH 7.0 phosphate buffer solution (PBS). Under the optimal conditions, the detection limit for individual determination of guanine and adenine was 6.0×10−9 M and 3.0×10−8 M (S/N =3), respectively. The proposed method for the measurements of guanine and adenine in herring sperm DNA was successfully applied with satisfactory results. [ABSTRACT FROM AUTHOR]

• A label-free and dual-amplified electrochemical bioanalysis is developed for sensitive detection of mucin 1. • The biosensor is based on a dual-amplification, originated from an inorganic-organic polymer hybrid mimic peroxidase (AuNPs@Cu 7 S 4 @Cu/Mn-AzoPPOP) and catalytic hairpin assembly. • The AuNPs@Cu 7 S 4 @Cu/Mn-AzoPPOP can not only serve as an label-free electrochemical probe, but also possesses significantly enhanced peroxidase-like catalytic activity. • AuNPs@Cu 7 S 4 @Cu/Mn-AzoPPOP generates a significantly enhanced CA and DPV signals towards the reduction of H 2 O 2. We constructed a label-free and dual-amplified electrochemical bioanalysis for ultrasensitive detection of mucin 1 (MUC1, a tumor biomarker for lung cancer, breast cancer, and ovarian cancer) based on an inorganic-organic polymer hybrid mimic peroxidase (AuNPs@Cu 7 S 4 @Cu/Mn-AzoPPOP) and catalytic hairpin assembly (CHA). The organic porous polymer (Cu/Mn-AzoPPOP) has a high surface area, which can load large amounts of Cu 7 S 4 and Au nanopartibcles (AuNPs). The formed inorganic-organic nanocomposite (AuNPs@Cu 7 S 4 @Cu/Mn-AzoPPOP) can not only serve as an electrochemical probe but also possesses significantly enhanced peroxidase-like performance, compared with that of only Cu 7 S 4 and only Cu/Mn-AzoPPOP. AuNPs@Cu 7 S 4 @Cu/Mn-AzoPPOP had high sensitivity towards the reduction of H 2 O 2 by means of differential pulse voltammetry (DPV) and chronoamperometry (CA). Based on the specific recognition between MUC1 and aptamers and its following cyclic reuse by simple strand displacement of CHA, further electrochemical signal amplification was achieved. The fabricated biosensor displayed ultra-sensitivity and highly selectivity for MUC1 determination, ranging from 1 fg/mL to 10 pg/mL, with low detection limits of 0.72 fg/mL (DPV) and 0.82 fg/mL (CA), respectively. Additionally, the proposed biosensor could also retain good performance in spiked serum samples, which implied its great promise for application in biomedical fields. [ABSTRACT FROM AUTHOR]

Abstract: Hypoxic preconditioning (HP) and stem cell transplantation have been extensively studied as individual therapies for ischemic stroke. The present investigation is an initial effort to combine these methods to achieve increased therapeutic effects after brain ischemia. Sublethal in vitro hypoxia pretreatment significantly enhanced the tolerance of neurally-differentiating embryonic stem (ES) cells and primary bone marrow mesenchymal stem cells (BMSC) to apoptotic cell death (40–50% reduction in cell death and caspase-3 activation). The HP protective effects on cultured cells lasted for at least 6 days. HP increased secretion of erythropoietin (EPO) and upregulated expression of bcl-2, hypoxia-inducible factor (HIF-1α), erythropoietin receptor (EPOR), neurofilament (NF), and synaptophysin in ES cell-derived neural progenitor cells (ES-NPCs). The HP cytoprotective effect was diminished by blocking EPOR, while pretreatment of ES-NPCs with recombinant human EPO mimicked the HP effect. HP-primed ES-NPCs survived better 3 days after transplantation into the ischemic brain (30–40% reduction in cell death and caspase-3 activation). Finally, transplanted HP-primed ES-NPCs exhibited extensive neuronal differentiation in the ischemic brain, accelerated and enhanced recovery of sensorimotor function when compared to transplantation of non-HP-treated ES-NPCs. The cell-priming strategy aimed to promote transplanted cell survival and their tissue repair capability provides a simple yet effective way of optimizing cell transplantation therapy. [Copyright &y& Elsevier]

Abstract: Although protein kinase C (PKC) plays a key role in ischemic preconditioning (IPC), the actual mechanism of that protection is unknown. We recently found that protection from IPC requires activation of adenosine receptors during early reperfusion. We, therefore, hypothesized that PKC might act to increase the heart''s sensitivity to adenosine. IPC limited infarct size in isolated rabbit hearts subjected to 30-min regional ischemia/2-h reperfusion and IPC''s protection was blocked by the PKC inhibitor chelerythrine given during early reperfusion revealing involvement of PKC at reperfusion. Similarly chelerythrine infused in the early reperfusion period blocked the increased phosphorylation of the protective kinases Akt and ERK1/2 observed after IPC. Infusing phorbol 12-myristate 13-acetate (PMA), a PKC activator, during early reperfusion mimicked IPC''s protection. As expected, the protection triggered by PMA at reperfusion was blocked by chelerythrine, but surprisingly it was also blocked by MRS1754, an adenosine A2b receptor-selective antagonist, suggesting that PKC was somehow facilitating signaling from the A2b receptors. NECA [5′-(N-ethylcarboxamido) adenosine], a potent but not selective A2b receptor agonist, increased phosphorylation of Akt and ERK1/2 in a dose-dependent manner. Pretreating hearts with PMA or brief preconditioning ischemia had no effect on phosphorylation of Akt or ERK1/2 per se but markedly lowered the threshold for NECA to induce their phosphorylation. BAY 60-6583, a highly selective A2b agonist, also caused phosphorylation of ERK1/2 and Akt. MRS1754 prevented phosphorylation induced by BAY 60-6583. BAY 60-6583 limited infarct size when given to ischemic hearts at reperfusion. These results suggest that activation of cardiac A2b receptors at reperfusion is protective, but because of the very low affinity of the receptors endogenous cardiac adenosine is unable to trigger their signaling. We propose that the key protective event in IPC occurs when PKC increases the heart''s sensitivity to adenosine so that endogenous adenosine can activate A2b-dependent signaling. [Copyright &y& Elsevier]

Abstract: Objective: Ischemic postconditioning protects the reperfused heart from infarction, and this protection is dependent on the occupancy of adenosine receptors. We further explored the role of adenosine receptors in this salvage. Methods: In situ rabbit hearts underwent 30min of regional ischemia and 3h of reperfusion, and postconditioning was effected with four cycles of 30-s reperfusion/30-s coronary artery occlusion at the end of ischemia. Results: Postconditioning reduced infarct size from 40.2±3.4% of the risk zone in untreated hearts to 15.5±2.5%. Protection by postconditioning was blocked by either the non-selective adenosine receptor blocker 8-p-(sulfophenyl)theophylline or the A2b-selective antagonist MRS 1754, injected intravenously 5min before reperfusion. The protein kinase C (PKC) antagonist chelerythrine also aborted postconditioning''s salvage, indicating a PKC-dependent mechanism. Neither the A1-selective antagonist 8-cyclopentyl-1,3-dipropylxanthine nor the A2a-selective antagonist 8-(13-chlorostyryl)caffeine had an effect on protection. The non-selective but A2b-potent adenosine agonist 5′-(N-ethylcarboxamido)adenosine (NECA) infused from 5min before to 1h after reperfusion mimicked postconditioning''s effect on infarct size (17.2±2.7% infarction) and MRS 1754 blocked the NECA-induced cardioprotection, confirming that A2b activation was protective. The PKC activator phorbol 12-myristate 13-acetate delivered just before reperfusion also duplicated the protective effect of postconditioning (16.3±4.1% infarction), and co-administration of the PKC antagonist chelerythrine aborted PMA''s protection, confirming that the protection was the result of PKC activation. NECA''s protective effect was not affected by chelerythrine, but rather MRS 1754 blocked PMA''s salutary effect (42.8±1.0% infarction), suggesting that the A2b receptor''s effect is under control of PKC. Finally, wortmannin, a blocker of phosphatidylinositol 3-kinase, also abrogated protection by PMA. Conclusions: Salvage of ischemic myocardium by postconditioning is dependent on activation of A2b receptors, which in turn depends on activation of PKC. It is still unclear why PKC activation is required to make the heart''s adenosine become protective. [Copyright &y& Elsevier]

Focal ischemia in the cerebral cortex results in acute and delayed cell death in the ischemic cortex and non-ischemic thalamus. We examined the hypothesis that neurons in ischemic and non-ischemic regions died from different mechanisms; specifically, we tested whether a mixed form of cell death containing both necrotic and apoptotic changes could be identified in individual cells.Focal barrel cortex ischemia in rats was induced by occlusion of small branches of the middle cerebral artery (MCA) corresponding to the barrel cortex, local blood flow was measured by quantitative autoradiography. Cell death was visualized by 2,3,5-triphenyltetrazolium chloride (TTC) staining, hematoxylin–eosin (H&E) staining, the terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), and caspase-3 staining 1 to 10 days after the ischemia. Electron microscopy was used for ultrastructural examination. Cell death occurred in the ipsilateral cortex 24 h after ischemia, followed by selective neuronal death in the ventrobasal (VB) thalamus 3 days later. TUNEL positive neurons were found in these two regions, but with striking morphological differences, designated as type I and type II TUNEL positive cells. The type I TUNEL positive cells in the ischemic cortex underwent necrotic changes. The type II TUNEL positive cells in the thalamus and the cortex penumbra region represented a hybrid death, featured by concurrent apoptotic and necrotic alterations in individual cells, including marked caspase-3 activation, nuclear condensation/fragmentation, but with swollen cytoplasm, damaged organelles and deteriorated membranes. Cell death in the thalamus and the cortex penumbra were attenuated by delayed administration of the caspase inhibitor benzyloxycarbonyl-Val–Ala–Asp fluoromethylketone (Z-VAD-FMK). Our data suggest that TUNEL staining should be evaluated with morphological changes, the hybrid death but not typical apoptosis occurs in the penumbra region and non-ischemic thalamus after cerebral ischemia. [Copyright &y& Elsevier]

An in situ model was used to test whether and how multiple occlusions at reperfusion can protect rabbit myocardium.Recently it was demonstrated that postconditioning in dogs salvaged ischemic myocardium.Control hearts underwent 30-min regional ischemia/3-h reperfusion, whereas in experimental hearts four postconditioning cycles of 30-s occlusion/30-s reperfusion starting 30 s after release of the index coronary occlusion were added in the presence or absence of various cell signaling antagonists.Postconditioning decreased infarction from 35.4 ± 2.7% of the risk zone in control hearts to 19.8 ± 1.8% (p < 0.05). Six cycles did not result in greater protection. If postconditioning cycles were begun after 10 min of reperfusion, protection was no longer evident. Either the non-selective KATP channel closer glibenclamide or the putatively selective mitochondrial KATP channel antagonist 5-hydroxydecanoate administered 5 min before reperfusion blocked the protection afforded by postconditioning, indicating involvement of the mitochondrial KATP channel. PD98059, a mitogen-activated protein/extracellular-signal regulated kinase (MEK) 1/2 and therefore extracellular-signal regulated kinase (ERK) inhibitor, and Nω-nitro-l-arginine methyl ester, an antagonist of nitric oxide synthase, infused shortly before reperfusion also aborted the protection afforded by postconditioning. Combined ischemic postconditioning and preconditioning resulted in significantly greater protection than either alone.Multiple, short, regional coronary occlusions immediately after prolonged myocardial ischemia are an effective cardioprotective intervention in the rabbit, and the mechanism of protection involves activation of ERK, production of nitric oxide, and opening of mitochondrial KATP channels. These observations suggest that a similar approach could be applied in the cardiac catheterization laboratory to protect reperfused myocardium after primary angioplasty in patients with acute myocardial infarction. [Copyright &y& Elsevier]

The adenosine A1/A2 adenosine agonist 5′-(N-ethylcarboxamido) adenosine (NECA) and bradykinin both limit infarction when administered at reperfusion in rabbits. This study compares the signal transduction pathways responsible for their anti-infarct effect. Receptor agonists were administered to isolated rabbit hearts starting 25 min after the onset of a 30-min period of ischemia and continued into the 2-h reperfusion period. Infarct size was measured. Both NECA and bradykinin decreased infarction from 31.5 ± 2.4% of the risk zone in untreated hearts to 11.8 ± 2.0% and 15.4 ± 2.4%, respectively (P < 0.05). Protection from both agents was blocked by PD98059, wortmannin, and Nω-nitro-L-arginine methyl ester (L-NAME), thus demonstrating dependence on activation of extracellular regulated kinase (ERK) and phosphatidylinositol 3-kinase (PI3K) and stimulation of nitric oxide synthase (NOS). Both wortmannin and PD98059 prevented phosphorylation of ERK 1/2 in NECA-treated hearts, whereas only wortmannin and not PD98059 blocked Akt phosphorylation. These data suggest Akt is upstream of ERK 1/2. In addition, 8-(3-chlorostyryl) caffeine blocked NECA’s protection indicating that A2 adenosine receptors trigger NECA’s anti-infarct effect. Of note, both bradykinin and acetylcholine (ACh) administered before ischemia to trigger preconditioning’s cardioprotection use PI3K and NOS in their signaling pathway. Curiously, however, ACh, unlike bradykinin, was not protective when administered at reperfusion. Hence, both NECA and bradykinin administered at reperfusion protect through a common signaling pathway that includes PI3K, NO, and ERK. [Copyright &y& Elsevier]