Fast Reaction Research Articles

Attention deployment in natural scenes: Higher-order scene statistics rather than semantics modulate the N2pc component.

Which properties of a natural scene affect visual search? We consider the alternative hypotheses that low-level statistics, higher-level statistics, semantics, or layout affect search difficulty in natural scenes. Across three experiments (n=20 each), we used four different backgrounds that preserve distinct scene properties: (a) natural scenes (all experiments); (b) 1/f noise (pink noise, which preserves only low-level statistics and was used in Experiments1 and 2); (c) textures that preserve low-level and higher-level statistics but not semantics or layout (Experiments2 and 3); and (d) inverted (upside-down) scenes that preserve statistics and semantics but not layout (Experiment2). We included "split scenes" that contained different backgrounds left and right of the midline (Experiment 1, natural/noise; Experiment 3, natural/texture). Participants searched for a Gabor patch that occurred at one of six locations (all experiments). Reaction times were faster for targets on noise and slower on inverted images, compared to natural scenes and textures. The N2pc component of the event-related potential, a marker of attentional selection, had a shorter latency and a higher amplitude for targets in noise than for all other backgrounds. The background contralateral to the target had an effect similar to that on the target side: noise led to faster reactions and shorter N2pc latencies than natural scenes, although we observed no difference in N2pc amplitude. There were no interactions between the target side and the non-target side. Together, this shows that-at least when searching simple targets without own semantic content-natural scenes are more effective distractors than noise and that this results from higher-order statistics rather than from semantics or layout.

Visible-light photoreduction of Cr(VI) over CdIn2S4/MOF-808 composites

Although solar-light driven photocatalysis is a promising route to reduce Cr(VI) from wastewater, its challenge is to construct highly efficient and muti-functional photocatalysts. Herein, CdIn2S4 combined with MOF-808 (CIS/MOF-808) composites were prepared for boosting solar-light induced photoreduction of Cr(VI). The close contact between MOF-808 and CdIn2S4 was favorable for the separation and transfer of electron-hole pairs, and provided sufficient vacant sites of Cr(VI) adsorption and photon capture. The removal activity of Cr(VI) over CIS/MOF-808 hybrids was higher than pristine MOF-808 and CdIn2S4. CdIn2S4 content, pH, and inorganic salts affected the removal efficiency of Cr(VI) and the concentration of Cr3+ in aqueous solution. The removal efficiency of Cr(VI) over 4-CIS/MOF with a nominal CdIn2S4 content of 16 wt. % was 95.45 %, and declined to 88.17 % after five cycles. The acidic medium induced to the fast reaction between Cr(VI) and e− to form Cr(III), while deteriorated the metal leaching as well as photo-corrosion to restrain the photocatalytic activity.

Constructing zinc-tin alloy interface for highly stable alkaline zinc anode

Aqueous alkaline zinc batteries have received widespread attention owing to its higher electrode potential and faster reaction kinetics compared to in mild aqueous electrolyte. However, Zn metal anode in alkaline electrolyte usually suffers more severe corrosion, passivation, and hydrogen evolution reaction. Herein, an interface chemical regulation strategy employs to in-situ construct a Zn-Sn alloy layer during cycling. The K2[Sn(OH)6] has been introduced into the electrolyte as the deposition overpotential of Zn and Sn in alkaline electrolyte is approximate leading to their simultaneously plating. The Zn-Sn alloy layer not only prevents Zn anode corrosion and suppresses the dendrite growth but also promotes the reaction kinetics. Therefore, the Zn||Zn cell exhibits a long life of 400 h in alkaline electrolyte about 20 times of that in without K2[Sn(OH)6] electrolyte. Moreover, the N-NCP@PQx||Zn full cell displays a superior cycle performance of 4000 cycles with 93% capacity retention at 2 A/g.

Sponge-like porous polyvinyl alcohol/chitosan-based hydrogel with integrated cushioning, pH-indicating and antibacterial functions

Developing a packaging material with integrated cushioning, intelligent and active functions is highly desired but remains challenging in the food industry. Here we show that a sponge-like porous hydrogel with pH-indicating and antibacterial additives can meet this requirement. We use polyvinyl alcohol and chitosan as the primary polymers to construct a hydrogel with hierarchical structures through a freeze-casting method in combination with salting-out treatment. The synergy of aggregated polymer chains and the sponge-like porous structure makes the hydrogel resilient and efficient in energy absorption. It also enables rapid movement of molecules/particles and fast reaction due to the large specific surface area of the pore structures and the large amount of free water in it, leading to a sensitive pH-indicating function. The hydrogel shows an obvious color variation within a wide pH range in 3 min. The silver nanoparticles are fixed in the dense polymer networks, enabling a lasting release of silver ions. The porous structure makes the silver ion reach the protected item in a short time, achieving an antibacterial effect against S. aureus and E. coli with little cytotoxicity. This work paves the way for fabricating multifunctional hydrogels for diverse advanced packaging systems.

Preparation of composites with MgAl-LDH-modified commercial activated carbon for the quick removal of Cr(VI) from aqueous solutions.

The problem of soil and water contamination caused by Cr(VI) discharged from the dyeing, electroplating, and metallurgical industries is becoming increasingly serious, posing a potentially great threat to the environment and public health. Therefore, it is crucial to develop a fast, efficient, and cost-effective adsorbent for remediating Cr-contaminated wastewater. In this work, MgAl-LDH/commercial-activated carbon nanocomposites (LDH-CACs) are prepared with hydrothermal. The effects of preparation and reaction conditions on the composite properties are first investigated, and then its adsorption behavior is thoroughly explored. Finally, a potential adsorption mechanism is proposed by several characterizations like SEM-EDS, XRD, FTIR, and XPS. The removal of Cr(VI) reaches 72.47% at optimal conditions, and the adsorption study demonstrates that LDH-CAC@1 has an extremely rapid adsorption rate and a maximum adsorption capacity of 116.7 mg/g. The primary removal mechanisms include adsorption-coupled reduction, ion exchange, surface precipitation, and electrostatic attraction. The reusability experiment illustrates that LDH-CAC@1 exhibits promising reusability. This study provides an effective adsorbent with a remarkably fast reaction, which has positive environmental significance for the treatment of Cr(VI) wastewater.

Droplet array with microfluidic concentration gradient (DA-MCG) for 2-dimensional reaction condition screening

Droplet microfluidic technology can use each microdroplet as a microreactor, which has the advantages of low reagent dosage, less cross contamination, and fast reaction time. Combining concentration gradient generation with droplet formation and capture to form a two-dimensional reaction condition screening platform (including reactant concentration and reaction time) is expected to broaden the application range of microfluidic screening. In this work, a microfluidic chip that can dynamically generate and capture microdroplets and form static microdroplet array was designed and fabricated. An optimized Christmas tree structure by adjusting the horizontal channel length ratio was used to generate a chemical concentration gradient while obtaining a uniform outlet flow rate, forming a droplet array with different concentrations. The performance of droplet array with microfluidic concentration gradient (DA-MCG) was verified using sodium fluorescein as a model reagent. The chromogenic reaction of NaOH and phenolphthalein, and luminol chemiluminescence reaction were used to verify the two-dimensional screening ability of DA-MCG. The results indicated that the DA-MCG has the potential to be applied in the field of multi-dimensional drug screening.

Thermo-chemical processes for the sustainable utilization of oil-bearing biomass: A case study on apricot seed valorization

This study investigated the thermochemical processing of defatted residue to achieve zero-waste utilization of oil-bearing biomass using apricot seed as the model compound. Defatted apricot seeds (DAS) obtained after oil extraction from apricot seed were valorized through pyrolysis platform, focusing on enhancing sustainability using CO2 as the reaction medium. The results showed that CO2 plays a crucial role in the pyrolysis process, leading to an enhanced CO formation through homogeneous reaction between CO2 and volatile matters stemming from DAS. Specifically, CO2 oxidized volatile matters while simultaneously reducing to CO and influenced the morphological properties of DAS biochars (DASBs), leading the development of pores with sizes of less than 16 nm and exceeding 50 nm. The larger pore size of DASBs fabricated under N2 and CO2, compared to 2 nm (the molecular size of triglycerides), makes them suitable as porous materials for thermally induced transesterification. The presence of alkaline metals in DASBs expedited thermally induced transesterification. At ≤ 330 °C, DASB fabricated under CO2 condition exhibited faster reaction kinetics than under N2 condition. This suggests that the use of CO2 in the fabrication of DASB results in favorable surface properties conducive to the thermally induced transesterification of apricot oil.

3D-printed channel-aligned core-sheath architecture with high sulfur loading for kinetics-enhanced Li–S battery

Sluggish kinetics in thick cathode with high sulfur (S) loading will lead to low active material utilization and fast capacity decay, thus hampering the practical applications of Li–S batteries. To tackle such issue, a slightly thickness-dependent cathode of activated carbon (AC)-S/single-walled carbon nanotube (SWNT)@SWNT with fast reaction kinetics is constructed via continuously printing core-sheath filaments. Such micro-filaments are composed of vertically aligned “thin AC-S/SWNT” in core layer and porous SWNT-strengthened shell layer, which constructs an appealing well-interconnected porous 3D architecture ensuring fast ion/electron/mass transport throughout the whole printed matrix, effectively expediting electrochemical kinetics even under a high S loading. Moreover, the SWNTs located in shell layer and intercalated in-between AC-S phase in core layer crosslink well for acting as the functional interlayer to suppress polysulfide shuttling, thereby enabling high S utilization. As a result, the 3D-printed thick AC-S/SWNT@SWNT cathode delivers outstanding gravimetric/areal capacity (752 mAh g−1/6.41 mAh cm−2 at 0.5C) and cycling performance under high S loading of 8.6 mg cm−2.

The impact of presentation modes on mental rotation processing: a comparative analysis of eye movements and performance

Mental rotation is the ability to rotate mental representations of objects in space. Shepard and Metzler’s shape-matching tasks, frequently used to test mental rotation, involve presenting pictorial representations of 3D objects. This stimulus material has raised questions regarding the ecological validity of the test for mental rotation with actual visual 3D objects. To systematically investigate differences in mental rotation with pictorial and visual stimuli, we compared data of N=54\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$N=54$$\\end{document} university students from a virtual reality experiment. Comparing both conditions within subjects, we found higher accuracy and faster reaction times for 3D visual figures. We expected eye tracking to reveal differences in participants’ stimulus processing and mental rotation strategies induced by the visual differences. We statistically compared fixations (locations), saccades (directions), pupil changes, and head movements. Supplementary Shapley values of a Gradient Boosting Decision Tree algorithm were analyzed, which correctly classified the two conditions using eye and head movements. The results indicated that with visual 3D figures, the encoding of spatial information was less demanding, and participants may have used egocentric transformations and perspective changes. Moreover, participants showed eye movements associated with more holistic processing for visual 3D figures and more piecemeal processing for pictorial 2D figures.

Reaction Rate and Stereoselectivity Enhancement in Glycosidations with O-Glycosyl Trihaloacetimidate Donors due to Catalysis by a Lewis Acid-Nitrile Cooperative Effect.

Activation of O-glycosyl trihaloacetimidate glycosyl donors with AuCl3 as a catalyst and pivalonitrile (tBuCN) as a ligand led to excellent glycosidation results in terms of yield and anomeric selectivity. In this way, various β-d-gluco- and β-d-galactopyranosides were obtained conveniently and efficiently. Experimental studies and density functional theory (DFT) calculations, in order to elucidate the reaction course, support formation of the tBuCN-AuCl2-OR(H)+ AuCl4- complex as a decisive intermediate in the glycosidation event. Proton transfer from this acceptor complex to the imidate nitrogen leads to donor activation. In this way, guided by the C-2 configuration of the glycosyl donor, the alignment of the acceptor complex enforces the stereoselective β-glycoside formation in an intramolecular fashion, thus promoting also a fast reaction course. The high stereocontrol of this novel 'Lewis acid-nitrile cooperative effect' is independent of the glycosyl donor anomeric configuration and without the support of neighboring group or remote group participation. The power of the methodology is shown by a successful glycoalkaloid solamargine synthesis.

Molybdenum Sulfide Nanoflowers as Electrodes for Efficient and Scalable Lithium-Ion Capacitors.

Hybrid supercapacitors (HSCs) bridge the unique advantages of batteries and capacitors and are considered promising energy storage devices for hybrid vehicles and other electronic gadgets. Lithium-ion capacitors (LICs) have attained particular interest due to their higher energy and power density than traditional supercapacitor devices. The limited voltage window and the deterioration of anode materials upsurged the demand for efficient and stable electrode materials. Two-dimensional (2D) molybdenum sulfide (MoS2) is a promising candidate for developing efficient and durable LICs due to its wide lithiation potential and unique layer structure, enhancing charge storage efficiency. Modifying the extrinsic features, such as the dimensions and shape at the nanoscale, serves as a potential path to overcome the sluggish kinetics observed in the LICs. Herein, the MoS2 nanoflowers have been synthesized through a hydrothermal route. The developed LIC exhibited a specific capacitance of 202.4 F g-1 at 0.25 A g-1 and capacitance retention of >90 % over 5,000 cycles. Using an ether electrolyte improved the voltage window (2.0 V) and enhanced the stability performance. The ex-situ material characterization after the stability test reveals that the storage mechanism in MoS2-LICs is not diffusion-controlled. Instead, the fast surface redox reactions, especially intercalation/deintercalation of ions, are more prominent for charge storage.

Design of microfluidic fluorescent sensor arrays for real-time and synchronously visualized detection of multi-component heavy metal ions

The majority of the environmental heavy metal ions exist in the form of multi-components, and the current single-to-single rapid detection methods are unable to meet the needs of simultaneous multi-component detection. Here, we have designed a microfluidic fluorescence sensor array by combining microfluidic sensing and organic fluorescent switches for the real-time and simultaneous visual detection of multi-component heavy metal ions. A series of “light-up” organic molecular probes was designed and synthesized, exhibiting a strong ability to bind heavy metal ions and resulting in the opening of probe fluorescence. Meanwhile, we design microfluidic sensor plate, the patterned path of the microfluidic plate has drainage channel wall and 2.70° downward slope, which can enable the samples to quickly reach the detection area. By loading organic molecular probes into the detection area, the microfluidic sensor array achieves simultaneous detection of four heavy metal ions. Combined with intelligent terminal, read and analyze the RGB color mode (RGB) results of detection, obtain quantitative information. The microfluidic fluorescence sensor array developed here can meet the requirements for in situ and semi-quantitative detection of a range of heavy metal ions with a low detection limit, fast reaction speed, and without the need for pretreatment. It represents a novel engineering technology approach for real-time detection of multi-components in the environment.

The Ugi4CR as effective tool to access promising anticancer isatin-based α-acetamide carboxamide oxindole hybrids.

Considering early-stage drug discovery programs, the Ugi four-component reaction is a valuable, flexible, and pivotal tool, facilitating the creation of two new amide bonds in a one-pot fashion to effectively yield the desired α-aminoacylamides. Here, we highlight the reputation of this reaction approach to access number and scaffold diversity of a library of isatin-based α-acetamide carboxamide oxindole hybrids, promising anticancer agents, in a mild and fast sustainable reaction process. The library was tested against six human solid tumor cell lines, among them, non-small cell lung carcinoma, cervical adenocarcinoma, breast cancer and colon adenocarcinoma. The most potent compounds 8d, 8h and 8k showed GI50 values in the range of 1-10 μM.

Universal, minute-scale synthesis of transition metal compound nanocatalysts via graphene-microwave system for enhancing sulfur kinetics in lithium-sulfur batteries

The application of Li-S batteries on large scale is held back by the sluggish sulfur kinetics and low synthesis efficiency of sulfur host. In addition, the preparation of catalysts that promote polysulfide redox kinetics is complex and time-consuming, reducing the cost of raw materials in Li-S. Here, a universal synthetic strategy for rapid fabrication of sulfur cathode and metal compounds nanocatalysts is reported based on microwave heating of graphene. Heat-sensitive materials can achieve rapid heating due to graphene reaching 500 ℃ within 4 s via microwave irradiation. The MoP-MoS2/rGO catalyst demonstrated in this work was synthesized within 60 s. When used for catalysts for Li-S batteries whose graphene/sulfur cathodes were also synthesized by microwave heating, enhanced catalytic effect for sulfur redox reaction was verified via experimental and DFT theoretical results. Benefiting from fast redox reaction (MoP), smooth Li+ diffusion pathways (MoS2), and large conductive network (rGO), the assembled Li-S battery with MoP-MoS2/rGO-Add@CS displays a remarkable initial specific capacity, stable lithium anode and good cycle stability (in pouch cells) using this two-pronged strategy. The work provides a practical strategy for advanced Li-S batteries toward a wide range of applications.

Change blindness, reward bias, negative affective priming: Exploring individual‐level associations between depression/anxiety symptoms and cognition

AbstractCognitive biases are thought to contribute to depression/anxiety. In addition to self‐reported measures, cognitive tasks could potentially be integrated with clinical practice as more precise measures of cognitive biases. In a large online study we explored the individual‐level association between depression/anxiety symptoms and performance on (1) reward bias, (2) negative affective priming, and (3) change blindness tasks. Participants completed tasks alongside depression/anxiety symptom questionnaires. We used regression analyses to test for associations between task performance and questionnaire scores. We conducted a replication study of the change blindness task, and performed a mega‐analysis of the two studies. Faster reaction time in the change blindness task was associated with higher depression score (B = −27, p = 0.034) in the first study (N = 545) and higher depression and anxiety scores (depression: B = −15, p = 0.045; anxiety: B = −17, p = 0.022) in the replication study (N = 616). These effects were significant in the mega‐analysis but did not withstand adjusting for age in either the original and replication studies or the mega‐analysis. We found no association between depression/anxiety and reward bias (N = 504) and negative affective priming (N = 539). Our results provide preliminary evidence that individuals with more severe depressive/anxious symptoms may be faster at identifying changes in the change blindness task. Contrary to previous findings, neither reward bias nor negative affective priming was associated with depression/anxiety.

Retention of 226Ra in the sandy Opalinus Clay facies from the Mont Terri rock laboratory, Switzerland

The safety assessment of deep geological disposal of nuclear waste requires a sound understanding of radionuclide retention in the repository host rocks. Here, we investigate the retention behaviour of the safety relevant radionuclide 226Ra in the heterogeneous sandy facies of the Opalinus Clay (OPA-SF) at the Mont Terri underground rock laboratory. Various rock samples were selected from a drill core (BAD-1) located in the lower sandy facies, which were representative for its textural and mineralogical heterogeneity. The samples were carefully characterized with respect to mineralogy and chemistry using X-Ray diffraction and electron microscopy. The amounts of quartz, carbonates and clay minerals in the samples ranged between 58 wt.% – 65 wt.%, 13 wt.% – 35 wt.% and 5 wt.% – 25 wt.%, respectively, underpinning the mineralogical heterogeneity. Rare (Ba,Sr)-sulphate precipitates were identified in the clay matrix by electron microscopy. The uptake behaviour of Ra was evaluated using batch sorption experiments. Corresponding to the mineralogical variability of the rock samples, the measured distribution ratios Rd for the 226Ra retention varied between 20 L kg−1 and 260 L kg−1 after 120 days. The experimental results and thermodynamic modelling approaches suggest that various processes contribute to the uptake of 226Ra on different time scales: fast cation exchange and surface complexation reactions by clay minerals and the (slower) formation of solid solutions during recrystallisation of (Ba,Sr)-sulphates as well as retention by carbonate minerals; the latter mechanism still requiring further investigation.

Cryolithionite‐based Pseudocapacitive Electrode for Sustainable Lithium‐ion Capacitors

Lithium‐ion insertion/deinsertion in anode at slow rates limits the power performance of energy storage devices. Here, a new pseudocapacitive electrode with high reversible capacity during cycling has been proposed for a lithium‐ion capacitor. The lithium‐fluoride garnet, namely Na3Fe2Li3F12, is obtained via precipitation from an aqueous solution at room temperature using abundant materials and exhibits a high discharge capacity of 746 mAh g‐1. After the first charging cycle, energy is stored via fast pseudocapacitive faradaic reactions which are facilitated by the nanocrystalline transport pathways with no structural modification to the electrode. The high stability window of F‐garnet allows extracting cell voltages of 2.2—3.2 V in a lithium‐ion capacitor where it is coupled with a porous carbon‐based positive electrode, with a high energy efficiency of 93 % maintained for 10000 charge/discharge cycles. This study opens new research direction concerning pseudocapacitive anode materials for the enhancing power performance and even replacing the traditional battery‐like anode materials.

The Programmable Catalytic Core of 8-17 DNAzymes.

8-17 DNAzymes (8-17, 17E, Mg5, and 17EV1) are in vitro-selected catalytic DNA molecules that are capable of cleaving complementary RNAs. The conserved residues in their similar catalytic cores, together with the metal ions, were suggested to contribute to the catalytic reaction. Based on the contribution of the less conserved residues in the bulge loop residues (W12, A15, A15.0) and the internal stem, new catalytic cores of 8-17 DNAzymes were programmed. The internal stem CTC-GAG seems to be more favorable for the DNAzymes than CCG-GGC, while an extra W12.0 led to a significant loss of activity of DNAzymes, which is contrary to the positive effect of A15.0, by which a new active DNAzyme 17EM was derived. It conducts a faster reaction than 17E. It is most active in the presence of Pb2+, with the metal ion preference of Pb2+ >> Zn2+ > Mn2+ > Ca2+ ≈ Mg2+. In the Pb2+ and Zn2+-mediated reactions of 17EM and 17E, the same Na+- and pH dependence were also observed as what was observed for 17E and other 8-17 DNAzymes. Therefore, 17EM is another member of the 8-17 DNAzymes, and it could be applied as a potential biosensor for RNA and metal ions.

The impact of music training on temporal order processing in Mandarin Chinese sentence reading: Evidence from event-related potentials (ERPs).

The objective of this study was to investigate the impact of music training on the processing of temporal order in Mandarin sentence reading using event-related potentials (ERPs). Two-clause sentences with temporal connectives ("before" or "after") were presented to both musicians and non-musicians. Additionally, a verbal N-back task was utilized to evaluate the participants' working memory capacities. The findings revealed that musicians, but not nonmusicians, demonstrated a more negative amplitude in the second clauses of "before" sentences compared with "after" sentences. In the N-back task, musicians exhibited faster reaction times than nonmusicians in the two-back condition. Furthermore, a correlation was observed between the ERP amplitude differences (before vs. after) and reaction time differences in the N-back task (0-back vs. 2-back) among musicians. These findings suggested that music training enhances the depth of temporal order processing, potentially mediated by improvements in working memory capacity.

A comprehensive understanding of the role of sodium sulfate in calcium looping via in-situ experiments and DFT studies: Performance and mechanism

Adding alkali metal salt promoters to calcium-based materials can influence the cycling performance of CaO-based sorbents. So far, most research on alkali metal salts focus on carbonate and chloride salts, while little attention is paid to sulfates. In this paper, we present an in-depth study of the role of Na2SO4 in calcium looping via in-situ experiments and DFT simulations. The results show that the effective conversion rate of Na2SO4-CaO after one cycle is 0.779 with the energy storage density of 2476.1 kJ/kg, while the effective conversion rate of CaO is 0.562 with the energy storage density of 1786.4 kJ/kg. After 80 cycles, the effective conversion and energy storage density of Na2SO4-CaO are lower than CaO, which is attributed to Na+ reducing the surface energy and accelerating the sintering. Moreover, an optimization strategy based on coordination effect among Na2SO4, CaO and inert oxides is proposed to slow down the sintering problems. Among them, Na2SO4-(CaO + ZnO) has the best adsorption performance and energy storage performance and ZnO is cheap, which can be considered a cost-effective sorbent. This work provides a new approach for developing efficient, simple and cost-effective calcium-based materials by simultaneously achieving fast reaction rates and good cycling stability of CaL.