Peek‐A‐Boo Test: A Simple Test for Assessing the Effect of Anxiolytics on Fish Behavior

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Abstract

The potential of pharmaceuticals and personal care products to alter the behavior of aquatic organisms is a growing concern. To assess the actual effect of these substances on aquatic organisms, a simple but effective behavioral test is required. We devised a simple behavioral (Peek-A-Boo) test to assess the effect of anxiolytics on the behavior of a model fish (medaka, Oryzias latipes). In the Peek-A-Boo test, we investigated the response of medaka to an image of a predator fish (donko fish, Odontobutis obscura). The test revealed that the time taken for test medaka exposed to diazepam (0.8, 4, 20, or 100 µg/L) to approach the image was shorter by a factor of 0.22 to 0.65, and the time spent in the area close to the image was longer by a factor of 1.8 to 2.7 than in the solvent control group for all diazepam exposure groups (p < 0.05). Hence, we confirmed that the test could detect changes in medaka behavior caused by diazepam with high sensitivity. The Peek-A-Boo test we devised is a simple behavioral test with high sensitivity for fish behavioral alteration. Environ Toxicol Chem 2023;00:1–6. © 2023 SETAC.

Investigating Possible Dipole‐Bound States of Cyanopolyynes: the Case for the C5N− Anion Detected in Interstellar Space.

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We present quantum structure calculations aimed at demon- strating the possible existence of dipole-bound states (DBS) for the anion C5N−, a species already detected in the Inter- stellar medium (ISM). The positive demonstration of DBS existence using ab initio studies is an important step to- ward elucidating possible pathways for the formation of the more tightly bound valence bound states (VBS) in envi- ronments where free electrons from starlight ionization pro- cesses are known to be available to interact with the radical partner of the title molecule. Our current calculations show that such DBS states can exist in C5N−, in agreement with what we had previously found for the smaller cyanopolyyne in the series: the C3N− anion. The predicted binding en- ergies which we found are 3 and 9 cm−1 for the 1Σ+ and 3Σ+ DBS, respectively. Furthermore, equilibrium geome- tries, equilibrium rotational constants, electric dipole mo- ments, and relative electronic energies were determined for the ground anion X1Σ+ and the two lowest electronic states of the parent neutral, X2Σ+ and A2Π.

Removal of Organochlorine Compounds from Coal Tar by Nucleophilic Substitution and Coalescence

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Removal of Organochlorine Compounds from Coal Tar by Nucleophilic Substitution and Coalescence

An integrated process of phase transfer nucleophilic substitution and coalescence separation is proposed to upgrade coal tar by removing organochlorine compounds (OOCs) and decreasing its moisture content. Different types of phase transfer catalysts and nucleophiles were selected to convert OOCs in coal tar. Glass fiber served as coalescence media to remove water and chloride compounds from coal tar simultaneously.


Abstract

An integrated process of phase transfer nucleophilic substitution and coalescence is proposed to upgrade coal tar by simultaneously removing organochlorine compounds (OOCs) and water. For the phase transfer catalysts (PTCs) and nucleophiles, polyethylene glycol 400 (PEG-400) and triethanolamine (TEOA) were the most effective to remove OOCs from coal tar. The optimal parameters of the dichlorination process in terms of molar ratio of PEG-400 and TEOA to OOCs, reaction temperature, reaction time, and stirring speed were determined. The chloride removal efficiency reached 80.66 % when glass fiber was used for oil-water coalescence separation. A promising method for simulllltaneously removing chloride and water from coal tar is provided.

Continuous Reactive Crystallization in a Mesoscale Oscillatory Baffled Reactor

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Continuous Reactive Crystallization in a Mesoscale Oscillatory Baffled Reactor

Continuous reactive crystallization of precipitated calcium carbonate (PCC) was performed in a mesoscale-oscillatory baffled reactor. Steady states were easily achieved due to a high degree of plug flow, with up to 95 % of solids suspended. The reactant concentration, the temperature, and the oscillation frequency have significant effects on the yield and particle size.


Abstract

Continuous reactive crystallization was carried out in a mesoscale oscillatory baffled reactor (meso-OBR), using calcium carbonate as a case study to demonstrate the ability of high solid loadings and to examine the fouling potential in continuous processes. Plug flow behavior was easily achieved in reactive solid-liquid phase reaction systems, as evidenced by the rapid establishment of a steady state. Effects of the operating conditions (reactant concentration, mixing conditions, and temperature) on the yield, particle size, and particle size distribution were studied. Increasing the reactant concentration and oscillation conditions reduced the particle size whereas increasing the operating temperature led to a large particle size. The meso-OBR produced uniformly shaped spherical crystals, with a 35 % reduction in average particle size and high purity compared to conventional stirred tanks. The meso-OBR could be used continuously for up to 6 h with less than 1 wt % of fouling (product loss).

Transition Metal‐Catalyzed Electroreductive Cross‐Couplings for C−C Bond Formation

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Transition Metal-Catalyzed Electroreductive Cross-Couplings for C−C Bond Formation

M.G. thanks the “China Scholarship Council” for the fellowship, and the authors are very grateful to the CNRS and Institut Polytechnique de Paris, which support this work.


Abstract

This mini review provides an overview of a range of Ni-, Co- and Pd-catalyzed electroreductive cross-coupling reactions. The combination of homogeneous transition-metal catalysis and electrochemistry are green alternatives to traditional reductive cross-coupling reactions to form Csp2-Csp2, Csp2-Csp3 and some Csp3-Csp3 bonds in one step. Most of these reactions use the sacrificial anode process.

Machine learning‐assisted study of correlation between post‐transition‐state bifurcation and initial phase information at the ambimodal transition state

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Machine learning-assisted study of correlation between post-transition-state bifurcation and initial phase information at the ambimodal transition state

The Diels–Alder cycloaddition of cyclopentadiene and nitroethene, the intramolecular cycloaddition between a diene and triene, and the Diels–Alder cycloaddition of 2-hydroxyacrolein with 1,3-butadiene involving post-transition-state bifurcation (PTSB) were investigated using the quasi-classical trajectory (QCT), classical molecular dynamics (MD), ring-polymer MD (RPMD) from the ambimodal transition state (TS), and machine-learning analysis. The PTSB dynamics are significantly influenced by the initial coordinates and momenta at the ambimodal TS.


Abstract

The Diels–Alder cycloaddition of cyclopentadiene and nitroethene, the intramolecular cycloaddition between a diene and triene, and the Diels–Alder cycloaddition of 2-hydroxyacrolein with 1,3-butadiene involving post-transition-state bifurcation (PTSB) were studied. These cycloaddition reactions were investigated using quasi-classical trajectory (QCT), classical molecular dynamics (MD), ring-polymer molecular dynamics (RPMD) simulations, and supervised machine-learning binary classification techniques. Room-temperature dynamics simulations started from the ambimodal transition state (TS) using the QCT, classical MD, and RPMD methods presented similar dynamics. Binary classification revealed that the initial geometry displacement from the ambimodal TS for the Diels–Alder cycloaddition of cyclopentadiene and nitroethene contributed to the branching dynamics and that the initial momenta for the intramolecular cycloaddition between a diene and triene and the Diels–Alder cycloaddition of 2-hydroxyacrolein with 1,3-butadiene played a significant role in the bifurcation dynamics.

Trace Doping: Fluorine‐Containing Hydrophobic Lewis Acid Enables Stable Perovskite Solar Cells

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With the rapid developments in perovskite solar cell (PSC), high efficiency has been achieved, but the long-term operational stability is still the most important challenges for the commercialization of this emerging photovoltaic technology. So far, bi-dopants Li-TFSI/t-BP doped hole-transporting materials (HTM) have led to state-of-the art efficiency in n-i-p PSCs. However, such dopants have several drawbacks in terms of stability, including the complex oxidation process, undesirable ion migration and ultra-hygroscopic nature. Herein, a fluorine-containing organic Lewis acid dopant bis(pentafluorophenyl)zinc (Zn-FP) with hydrophobic property and high migration barrier has been employed as a potential alternative to widely employed bi-dopants Li-TFSI/t-BP for PTAA. The resulting Zn-FP-based PSCs achieve a maximum PCE of 20.34% with J-V  hysteresis-free. Specifically, the unencapsulated device exhibits significantly advancement of operational stability under the International Summit on Organic Photovoltaic Stability protocols (ISOS-L-1), maintaining over 90% of the original efficiency after operation for 1000 hours under continuous 1-sun equivalent illumination in N2 atmosphere in both forward and reverse J-V scan.