Highly Efficient Aggregation-Induced Enhanced Electrochemiluminescence of Cyanophenyl-Functionalized Tetraphenylethene and Its Application in Biothiols Analysis.

Exploring new electrochemiluminescence (ECL) luminophores with high ECL efficiency and good stability in aqueous solution is in great demand for biological sensing. In this work, highly efficient aggregation-induced enhanced ECL of cyanophenyl-functionalized tetraphenylethene (tetra[4-(4-cyanophenyl)phenyl]ethene, TCPPE) and its application in biothiols analysis were reported. TCPPE contains four 4-cyanophenyl groups covalently attached to the tetraphenylethene (TPE) core, generating a nonplanar three-dimensional twisted conformation structure. TCPPE nanoparticles (NPs) with an average size of 15.84 nm were prepared by a precipitation method. High ECL efficiency (593%, CdS as standard) and stable ECL emission (over one month) were obtained for TCPPE NPs in aqueous solution. The unique properties of TCPPE NPs could be ascribed to the efficient suppression of nonradiative transition, the decrease of the energy gap, and the increase of anionic radical stability, which were proved by theoretical calculation and electrochemical and fluorescence methods. Contrasting aggregation-induced ECL chromic emission was first observed for TCPPE NPs. As a proof-of-methodology, an ECL method was developed for three biothiol assays with detection limits of 6, 7, and 300 nM for cysteine, homocysteine, and glutathione, respectively. This work demonstrates that TCPPE NPs are promising ECL luminophores, and the incorporation of appropriate substituents into luminophores can improve ECL efficiency and radical stability.

An Efficient Electron Donor for Conjugated Microporous Polymer Photocatalysts with High Photocatalytic Hydrogen Evolution Activity.

Conjugated microporous polymers (CMPs) with donor-acceptor (D-A) molecular structure show high photocatalytic activity for hydrogen evolution due to the efficient light-induced electron/hole separation, which is mostly determined by the nature of electron donor and acceptor units. Therefore, the selection of electron donor and acceptor holds the key point to construct high performance polymer photocatalysts. Herein, two dibenzo[b,d]thiophene-S,S-dioxide (BTDO) containing CMP photocatalysts using tetraphenylethylene (TPE) or dibenzo[g,p]chrysene (DBC) as the electron donor to investigate the influence of the geometry of electron donor on the photocatalytic activity are design and synthesized. Compared with the twisted TPE donor, DBC has a planar molecular structure with extended π-conjugation, which promotes the charges transmission and light-induced electron/hole separation. As a result, the polymer DBC-BTDO produced from DBC donor shows a remarkable photocatalytic hydrogen evolution rate (HER) of 104.86 mmol h-1  g-1 under full arc light (λ > 300 nm), which is much higher than that of the polymer TPE-BTDO (1.80 mmol h-1  g-1 ), demonstrating that DBC can be an efficient electron donor for constructing D-A polymer photocatalysts with high photocatalytic activity for hydrogen evolution.

Substrate-Photocaged Enzymatic Fluorogenic Probe Enabling Sequential Activation for Light-Controllable Monitoring of Intracellular Tyrosinase Activity.

Tyrosinase (TYR) is a crucial enzyme involved in melanogenesis, and its overexpression is closely associated with melanoma. To precisely monitor intracellular TYR activity, remote control of a molecule imaging tool is highly meaningful but remains to be explored. In this work, we present the first photocaged tyrosinase fluorogenic probe by caging the substrate of the enzymatic probe with a photolabile group. Because of the sequential light and enzyme-activation feature, this probe exhibits photocontrollable "turn on" response toward TYR with good selectivity and high sensitivity (detection limit: 0.08 U/mL). Fluorescence imaging results validate that the caged probe possesses the capability of visualizing intracellular endogenous tyrosinase activity in a photocontrol fashion, thus offering a promising molecule imaging tool for investigating TYR-related physiological function and pathological role. Moreover, our sequential activation strategy has great potential for developing more photocontrollable enzymatic fluorogenic probes with spatiotemporal resolution.

Efficacy of novel nano-hydroxyapatite/polyurethane composite scaffolds with silver phosphate particles in chronic osteomyelitis.

Recently, chronic osteomyelitis is still a challenging surgical problem. Unfortunately, the traditional clinical method using bone cement loaded antibiotics is restricted due to its non-biodegradability and limited release of antibiotics. Hydroxyapatite is a good adsorbent with good biocompatibility, an ideal bone repair material, and can avert the requirement for the secondary surgical procedure of removal. In this study, nano-hydroxyapatite combined with a polyurethane containing 3% silver (Ag/n-HA/PU) was synthesized, and investigated for its efficacy of treating chronic bone infection with bone defects. To clarify its silver ions release characteristics, the concentration of the Ag+ in the elution was analyzed every day after in vitro deionized water immersion. A chronic osteomyelitis of tibia in rabbit model was established, and 70 New Zealand rabbits were divided into 4 groups, including the blank control group, nano-hydroxyapatite combined with polyurethane (n-HA/PU) implant group, 3% Ag/n-HA/PU group and 10% Ag/n-HA/PU group after debridement. Routine blood tests, radiography, Micro-CT, and histological staining were conducted at 4 days, 3, 6 and 12 weeks post-treatment. The results showed that the released silver from the 3% Ag/n-HA/PU and 10% Ag/n-HA/PU exhibited an initial burst release and followed by a slow controlled release up to 39 days and 42 days respectively. A good repair of bone defects, an appropriate rate of degradation of scaffolds and no significant toxicity were observed in the 3% Ag/n-HA/PU group, indicating the advantages of this novel synthetic scaffold to be a potential option for the treatment of chronic osteomyelitis. A novel nano-composite, nano-hydroxyapatite combined with a polyurethane containing 3% silver (Ag/n-HA/PU) provide controlled release of Ag+, illustrated by its abilities of biodegradation, antimicrobial activity, and favorable repair of bone defects in the treatment of chronic osteomyelitis.

Effect of Isomeric Structures on Photovoltaic Performance of D-A Copolymers.

Two donor-acceptor copolymers based on isomeric acceptor units, [7,7'-bithieno[2',3':4,5]thieno[2,3-d]thieno[3,2-b]pyridine]-5,5'(4H,4'H)-dione (BTTP) and [2,2'-bithieno[2',3':4,5]thieno[2,3-d]thieno[3,2-b]pyridine]-5,5'(4H,4'H)-dione (iBTTP), are developed to study the effect of isomeric structures on photovoltaic performance. Compared with PBDTBTTP, PBDTiBTTP possesses a smaller bandgap for good light harvesting and a better π-π stacking for higher hole mobility. PBDTiBTTP solar cells present balanced mobilities and good nanoscale phase separation, giving a power conversion efficiency (PCE) of 6.51%, with higher short-circuit current (Jsc ) and fill factor (FF).

Synthetic Control and Multifunctional Properties of Fluorescent Covalent Triazine-Based Frameworks.

Conjugated microporous polymers (CMPs), with the virtue of high porosity and optoelectronic activity, are attracting increasing research interest and have been used in various environmental and energy areas. Efficient synthesis and the exploitation of new functionalities are the research hotspots in the CMPs research area. Covalent triazine frameworks (CTFs) synthesized by CF3 SO3 H catalyzed trimerization reactions show properties quite alike to CMPs and this method avoids the use of noble metal catalysts. In this study, a series of novel fluorescent covalent triazine-based frameworks (F-CTFs) is prepared using different tetra-cyano compounds as the starting monomers. Both porosity and fluorescence properties of the F-CTFs can be adjusted by the monomer structure. Gas adsorption measurement reveals that F-CTF1 with the largest surface area of 896 m(2) g(-1) shows the highest CO2 uptake of 3.29 mmol g(-1) at 273 K and 1.13 bar among the polymers. Taking advantages of their large surface areas and strong fluorescence, these F-CTFs could be used as efficient chemical sensing agents for various nitroaromatic compounds as well.

Tunable organic photocatalysts for visible-light-driven hydrogen evolution.

Photocatalytic hydrogen production from water offers an abundant, clean fuel source, but it is challenging to produce photocatalysts that use the solar spectrum effectively. Many hydrogen-evolving photocatalysts are active in the ultraviolet range, but ultraviolet light accounts for only 3% of the energy available in the solar spectrum at ground level. Solid-state crystalline photocatalysts have light absorption profiles that are a discrete function of their crystalline phase and that are not always tunable. Here, we prepare a series of amorphous, microporous organic polymers with exquisite synthetic control over the optical gap in the range 1.94-2.95 eV. Specific monomer compositions give polymers that are robust and effective photocatalysts for the evolution of hydrogen from water in the presence of a sacrificial electron donor, without the apparent need for an added metal cocatalyst. Remarkably, unlike other organic systems, the best performing polymer is only photoactive under visible rather than ultraviolet irradiation.

Synthesis and gas adsorption properties of tetra-armed microporous organic polymer networks based on triphenylamine.

Two novel tetra-armed microporous organic polymers have been designed and synthesized via a nickel-catalyzed Yamamoto-type Ullmann cross-coupling reaction or Suzuki cross-coupling polycondensation. These polymers are stable in various solvents, including concentrated hydrochloric acid, and are thermally stable. The homocoupled polymer YPTPA shows much higher Brunauer-Emmet-Teller-specific surface area up to 1557 m(2) g(-1) than the copolymer SPTPA (544 m(2) g(-1)), and a high CO2 uptake ability of 3.03 mmol g(-1) (1.13 bar/273 K) with a CO2 /N2 sorption selectivity of 17.3:1. Both polymers show high isosteric heats of CO2 adsorption (22.7-26.5 kJ mol(-1)) because the incorporation of nitrogen atoms into the skeleton of microporous organic polymers enhances the interaction between the pore wall and the CO2 molecules. The values are higher than those of the porous aromatic frameworks, which contain neither additional polar functional groups nor nitrogen atoms, and are rather close to those of previously reported microporous organic polymers containing the nitrogen atoms on the pore wall. These data show that these materials would be potential candidates for applications in post-combustion CO2 capture and sequestration technology.

An ERP study on the certainty of epistemic modality in predictive inference processing.

Previous psychological experiments have shown that predictive inference processing under different textual constraints is modulated by the directionality function of epistemic modality (EM) certainty within the context. Nevertheless, recent neuroscientific studies have not presented positive evidence for such a function during text reading. Consequently, the current study deposited Chinese EMs "" (possibly) and "" (surely) into a predictive inference context to examine whether a directionality of EM certainty influences the processing of predictive inference via the ERP technique. Two independent variables, namely textual constraint and EM certainty, were manipulated, and 36 participants were recruited. The results revealed that, in the anticipatory stage of predictive inference processing while under a weak textual constraint, low certainty evoked a larger N400 (300-500 ms) in the fronto-central and centro-parietal regions, indicating the augmentation of cognitive loads in calculating the possibility of representations of the forthcoming information. Meanwhile, high certainty elicited a right fronto-central late positive component (LPC) (500-700 ms) associated with semantically congruent but lexically unpredicted words. In the integration stage, low certainty resulted in larger right fronto-central and centro-frontal N400 (300-500 ms) effects in the weak textual constraint condition, associated with the facilitation of lexical-semantic retrieval or pre-activation, and high certainty successively elicited right fronto-central and centro-parietal LPC (500-700 ms) effects, associated respectively with lexical unpredictability and reanalysis of the sentence meaning. The results support the directionality function of EM certainty and reveal the complete neural processing of predictive inferences with high and low certainties under different textual constraint conditions.

Towards Durable and High-Rate Rechargeable Aluminum Dual-ion Batteries via a Crosslinked Diphenylphenazine-based Conjugated Polymer Cathode.

Rechargeable aluminum battery (RAB) is expected to be a promising energy storage technique for grid-scale energy storage. However, the development of RABs is seriously plagued by the lack of suitable cathode materials. Herein, we report two p-type conjugated polymers of L-PBPz and C-PBPz with the same building blocks of diphenylphenazine but different linkage patterns of linear and crosslinked structures as the cathode materials for Al dual-ion batteries. Compared to the linear polymer skeleton in L-PBPz, the crosslinked structure endows C-PBPz with amorphous nature and low dihedral angles of the polymer chains, which severally contribute to the fast diffusion of AlCl4 - with large size and the electron transfer during the redox reaction of diphenylphenazine. As a result, C-PBPz delivers a much better rate performance than L-PBPz. The crosslinked structure also leads to a stable cyclability with over 80000 cycles for C-PBPz. Benefiting from the fast kinetics, meanwhile, the C-PBPz cathode could realize a high redox activity of 117 mAh g-1, corresponding to an areal capacity of 2.30 mAh cm-2, even under a high mass loading of 19.7 mg cm-2 and a low content of 10 wt% conductive agent. These results might boost the development of polymer cathodes for RABs.

Rational design of triazine-based conjugated polymers with enhanced charge separation ability for photocatalytic hydrogen evolution.

Triazine-based conjugated polymers (TCPs) are promising organic catalysts for green H2 production, since their photocatalytic performance can be easily regulated via appropriate molecular design. However, apart from weak absorption of visible light, weak charge separation and transport abilities also considerably restrict the photocatalytic performance of TCPs. Herein, we report two novel TCP photocatalysts with donor-acceptor (D-A) and donor-π-acceptor (D-π-A) structures using dibenzo[g,p]chrysene (Dc), thiophene (T), and 2,4,6-triphenyl-1,3,5-triazine (Tz) as the donor, π-spacer, and acceptor, respectively. Compared to Dc-Tz with a D-A structure, Dc-T-Tz exhibits a broader light absorption edge and more efficient charge separation and transmission due to its D-π-A structure and strong dipole effect. These properties enable Dc-T-Tz to display a prominent H2 production rate of 45.13 mmol h-1 g-1 under ultraviolet-visible (UV-Vis) light (λ > 300 nm). Therefore, Dc-T-Tz represents state-of-the-art TCP photocatalysts to date.

Expression of concern: Enhanced photocatalytic activity of g-C3N4/MnO composites for hydrogen evolution under visible light.

Expression of concern for 'Enhanced photocatalytic activity of g-C3N4/MnO composites for hydrogen evolution under visible light' by Na Mao et al., Dalton Trans., 2019, 48, 14864-14872, https://doi.org/10.1039/C9DT02748C.

The knowledge domain of cognitive neuroscience of aging: A Scientometric and bibliometric analysis.

Cognitive neuroscience of aging (CNA) is a relatively young field compared with other branches of cognitive aging (CA). From the beginning of this century, scholars in CNA have contributed many valuable research to explain the cognitive ability decline in aging brains in terms of functional changes, neuromechanism, and neurodegenerative diseases. However, very few studies have systematically reviewed the research in the domain of CAN, with regard to its primary research topics, theories, findings, and future development. Therefore, this study used CiteSpace to conduct a bibliometric analysis of 1,462 published articles in CNA from Web of Science (WOS) and investigated the highly influential and potential research topics and theories of CNA, as well as important brain areas involved in CAN during 2000-2021. The results revealed that: (1) the research topics of "memory" and "attention" have been the focus of most studies, progressing into a fMRI-oriented stage; (2) the scaffolding theory and hemispheric asymmetry reduction in older adults model hold a key status in CNA, characterizing aging as a dynamic process and presenting compensatory relationships between different brain areas; and (3) age-related changes always occur in temporal (especially the hippocampus), parietal, and frontal lobes and the cognitive declines establish the compensation relationship between the anterior and posterior regions.

Molecular Engineering in D-π-A-A-Type Conjugated Microporous Polymers for Boosting Photocatalytic Hydrogen Evolution.

Conjugated microporous polymer (CMP) photocatalysts with donor-π-acceptor (D-π-A) or donor-acceptor (D-A) structures have garnered great attention for solar-driven hydrogen generation because of their inherent charge separation nature and high surface area. Herein, we design a series of D-π-A-A-type CMP photocatalysts to uncover the influence of the content of the dibenzo[b,d]thiophene-S-S-dioxide (BTDO) acceptor on the photocatalytic activity. The results demonstrate that the acceptor content in the D-π-A-A-type CMP photocatalysts affects the electronic structure, the availability of reaction sites, and the separation between light-generated electrons and holes, which mainly determine the photocatalytic performance for H2 release. Benefiting from the synergy of light absorption, hydrophilicity, and active sites, the bare polymer PyT-BTDO-2 with an optimized BTDO content exhibits a high H2 production rate of 230.06 mmol h-1 g-1 under simulated sunlight, manifesting that the strategy of D-π-A-A structural design is efficacious for boosting the photocatalytic performance of CMP photocatalysts.

An efficient electron donor containing a silicon heteroatom for organic photocatalysts with high hydrogen production activity.

We report here 4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b']dithiophene (SiDT) as an electron donor to construct a donor-acceptor type conjugated polymer (PSiDT-BTDO) photocatalyst with a narrow band gap by employing dibenzo[b,d]thiophene-S,S-dioxide as an electron acceptor. The resulting polymer PSiDT-BTDO could realize a high hydrogen evolution rate of 72.20 mmol h-1 g-1 under ultraviolet-visible light with a Pt co-catalyst, due to the enhanced hydrophilicity as well as the decreased recombination rate of photo-induced holes/electrons and the dihedral angles of the polymer chains. The high photocatalytic activity of PSiDT-BTDO reveals the promising application of the SiDT donor in designing high-performance organic photocatalysts for hydrogen evolution.

Evidence for dynamic attentional bias toward positive emotion-laden words: A behavioral and electrophysiological study.

There has been no consensus on the neural dissociation between emotion-label and emotion-laden words, which remains one of the major concerns in affective neurolinguistics. The current study adopted dot-probe tasks to investigate the valence effect on attentional bias toward Chinese emotion-label and emotion-laden words. Behavioral data showed that emotional word type and valence interacted in attentional bias scores with an attentional bias toward positive emotion-laden words rather than positive emotion-label words and that this bias was derived from the disengagement difficulty in positive emotion-laden words. In addition, an attentional bias toward negative emotion-label words relative to positive emotion-label words was observed. The event-related potential (ERP) data demonstrated an interaction between emotional word type, valence, and hemisphere. A significant hemisphere effect was observed during the processing of positive emotion-laden word pairs rather than positive emotion-label, negative emotion-label, and negative emotion-laden word pairs, with positive emotion-laden word pairs eliciting an enhanced P1 in the right hemisphere as compared to the left hemisphere. Our results found a dynamic attentional bias toward positive emotion-laden words; individuals allocated more attention to positive emotion-laden words in the early processing stage and had difficulty disengaging attention from them in the late processing stage.

Mechano-chromic and mechano-enhanced electrogenerated chemiluminescence of tetra[4-(4-cyanophenyl)phenyl]ethene.

Mechano-chromic and mechano-enhanced electrogenerated chemiluminescence (ECL) from tetra[4-(4-cyanophenyl)phenyl]ethene (TCPPE) is reported for the first time. TCPPE displays intense mechano-enhanced ECL (ΦECL,crystal = 12.1%, ΦECL,ground = 75.5%) and contrastingly mechano-chromic ECL (λECL,crystal = 478 nm, λECL,ground = 528 nm). The application of TCPPE as sensitive bi-functional mechanical force reporters is successfully performed in rewritable and optical-recording applications.

Quinone-based conjugated polymer cathodes synthesized via direct arylation for high performance Li-organic batteries.

Direct arylation cross-coupling reaction was employed to prepare quinone-based conjugated polymer cathodes, which realize a high reversible capacity of 200 mA h g-1 at 0.05 A g-1, an excellent rate capability of 111 mA h g-1 at 30 A g-1 (150C), and a stable cycling performance for more than 3000 cycles.

A low-cost naphthaldiimide based organic cathode for rechargeable lithium-ion batteries.

Recently, the development of cathode materials is becoming an important issue for lithium-ion batteries (LIBs). Compared with inorganic cathodes, the organic cathodes are developing rapidly, ascribing to their distinct merits in light weight, low cost, massive organic resources and high capacity. In this paper, a cost-efficiency naphthaldiimide (NDI) based derivative, 2,7-bis(2-((2-hydroxyethyl) amino) ethyl) benzo[lmn] [3,8] phenanthroline-1,3,6,8(2H, 7H)-tetraone (NDI-NHOH), was used as organic cathode in LIBs. The NDI-NHOH was synthesized easily via one-step process, and it showed very high thermal stability. Through mixing NDI-NHOH with acetylene black and polyvinylidene fluoride (weight ratio of 6:3:1) as composite cathode in lithium-metal based LIBs, the NDI-NHOH presented versatile electrochemical properties. From cyclic voltammetry (CV) test, it exhibited two reversible peaks for oxidation and reduction in the first cycle, respectively. Notably, the oxidation and reduction peaks were located at 2.54, 3.22 and 2.14, 2.32 V vs. Li+/Li, respectively. By employing NDI-NHOH as cathode, it demonstrated a specific capacity of about 80 mAh g-1 in the range of 1.5-3.5 V, where the batteries retained a capacity retention of 50% over 20 cycles. According to the LIBs study, it suggests that the NDI-NHOH-based derivative shows a potentially promising candidate as efficient organic cathode materials for high-performance metal-ions batteries.

Synthetic Control of Electronic Property and Porosity in Anthraquinone-Based Conjugated Polymer Cathodes for High-Rate and Long-Cycle-Life Na-Organic Batteries.

Redox-active carbonyl-containing compounds have received extensive attention as cathode materials for sodium-ion batteries (SIBs) because of their excellent attributes, including elemental sustainability, high theoretical capacity, diverse structures, and tunable properties. However, the storage of Na+ in most carbonyl-based cathode materials is plagued by the low capacity, unsatisfying rate performance, and short cycling life. Herein, we develop a series of anthraquinone-based conjugated polymer cathodes consisting of anthraquinone and benzene with different linking patterns. It reveals that the linkage sites on benzene ring could affect the electronic structures of the resulting polymers and thus their charge-storage capabilities. The 1,2,4,5-linkage on benzene leads to a high surface area, a narrow band gap, and the lowest unoccupied molecular orbital for the resulting polymer PBAQ-3. As a cathode for SIBs, it delivers a high capacity of around 200 mAh g-1 and excellent rate performance (105 mAh g-1 at 200 C) as well as stable cycling with a capacity retention of 95.8% after 1000 cycles at 0.05 A g-1 and 83.1% after 40000 cycles at 3 A g-1. Our findings highlight the influence of linking patterns of the building blocks on the electrochemical performance of organic electrodes.