Retarding anion migration for alleviating concentration polarization towards stable polymer lithium-metal batteries.

Traditional dual-ion lithium salts have been widely used in solid polymer lithium-metal batteries (LMBs). Nevertheless, concentration polarization caused by uncontrolled migration of free anions has severely caused the growth of lithium dendrites. Although single-ion conductor polymers (SICP) have been developed to reduce concentration polarization, the poor ionic conductivity caused by low carrier concentration limits their application. Herein, a dual-salt quasi-solid polymer electrolyte (QSPE), containing the SICP network as a salt and traditional dual-ion lithium salt, is designed for retarding the movement of free anions and simultaneously providing sufficient effective carriers to alleviate concentration polarization. The dual salt network of this designed QSPE is prepared through in-situ crosslinking copolymerization of SICP monomer, regular ionic conductor, crosslinker with the presence of the dual-ion lithium salt, delivering a high lithium-ion transference number (0.75) and satisfactory ionic conductivity (1.16 × 10-3 S cm-1 at 30 °C). Comprehensive characterizations combined with theoretical calculation demonstrate that polyanions from SICP exerts a potential repulsive effect on the transport of free anions to reduce concentration polarization inhibiting lithium dendrites. As a consequence, the Li||LiFePO4 cell achieves a long-cycle stability for 2000 cycles and a 90% capacity retention at 30 °C. This work provides a new perspective for reducing concentration polarization and simultaneously enabling enough lithium-ions migration for high-performance polymer LMBs.

Is This Safe? Examining Safety Assessments of Illicit Drug Purchasing on Social Media Using Conjoint Analysis.

Background: Illicit substance sales facilitated by social media platforms are a growing public health issue given recent increases in overdose deaths, including an alarming rise in cases of fentanyl poisoning. However, little is known about how online users evaluate what features of social media posts convey safety, which can influence their intent to source illicit substances. Objectives: This study adapts conjoint analysis which assessed how attributes of social media posts (i.e., features) influence safety evaluations of mock posts selling illicit substances. 440 participants were recruited online for self-reporting use or purchase of controlled substances or prescription medicines recreationally. The following attributes were tested: drug packaging, drug offerings, profile photo of seller, payment info provided, and use of emojis. Results: Packaging was ranked the most important attribute (Average Importance =43.68, Offering=14.94, Profile=13.86, Payment=14.11, Emoji=13.41), with posts that displayed drugs in pill bottles assessed as the most safe. Attribute levels for advertising multiple drugs, having a blank profile photo, including payment information, and including emojis also ranked higher in perceived safety. Rankings were consistent across tested demographic factors (i.e., gender, age, and income). Survey results show that online pharmacies were most likely to be perceived as safe for purchasing drugs and medications. Additionally, those who were younger in age, had higher income, and identified as female were more likely to purchase from a greater number of platforms. Conclusions: These findings can assist in developing more precise content moderation for platforms seeking to address this ongoing threat to public safety.

Highly Electrically Conductive Polyiodide Ionic Liquid Cathode for High-Capacity Dual-Plating Zinc-Iodine Batteries.

Zinc-iodine batteries are one of the most intriguing types of batteries that offer high energy density and low toxicity. However, the low intrinsic conductivity of iodine, together with high polyiodide solubility in aqueous electrolytes limits the development of high-areal-capacity zinc-iodine batteries with high stability, especially at low current densities. Herein, we proposed a hydrophobic polyiodide ionic liquid as a zinc-ion battery cathode, which successfully activates the iodine redox process by offering 4 orders of magnitude higher intrinsic electrical conductivity and remarkably lower solubility that suppressed the polyiodide shuttle in a dual-plating zinc-iodine cell. By the molecular engineering of the chemical structure of the polyiodide ionic liquid, the electronic conductivity can reach 3.4 × 10-3 S cm-1 with a high Coulombic efficiency of 98.2%. The areal capacity of the zinc-iodine battery can achieve 5.04 mAh cm-2 and stably operate at 3.12 mAh cm-2 for over 990 h. Besides, a laser-scribing designed flexible dual-plating-type microbattery based on a polyiodide ionic liquid cathode also exhibits stable cycling in both a single cell and 4 × 4 integrated cell, which can operate with the polarity-switching model with high stability.

Propargylic Amination Enabled the Access to Enantioenriched Acyclic α-Quaternary α-Amino Ketones.

A propargylic amination approach toward chiral acyclic α-quaternary α-amino ketones is described. This Cu-catalyzed procedure could be performed open to air using commercially available amines as nucleophiles. The key to success is the use of rationally designed propargylic cyclic carbonates as substrates, which can generate a Cu-bonded enolate zwitterionic intermediate upon decarboxylation. This protocol features wide functional group tolerance and high asymmetric induction, with typical ee value higher than 93%, and thus advances a great step forward in the challenging synthesis of acyclic chiral α-quaternary α-amino ketones.

Design, synthesis, and bioassay of 4-thiazolinone derivatives as influenza neuraminidase inhibitors.

A series of 4-thiazolinone derivatives (D1-D58) were designed and synthesized. All of the derivatives were evaluated in vitro for neuraminidase (NA) inhibitory activities against influenza virus A (H1N1), and the inhibitory activities of the five most potent compounds were further evaluated on NA from two different influenza viral subtypes (H3N2 and B), and then their in vitro anti-viral activities were evaluated using the cytopathic effect (CPE) reduction assay. The results showed that the majority of the target compounds exhibited moderate to good NA inhibitory activity. Compound D18 presented the most potent inhibitory activity with IC50 values of 13.06 µM against influenza H1N1 subtype. Among the selected compounds, D18 and D41 turned out to be the most potent inhibitors against influenza virus H3N2 subtype (IC50 = 15.00 µM and IC50 = 14.97 µM, respectively). D25 was the most potent compound against influenza B subtype (IC50 = 16.09 µM). In addition, D41 showed low toxicity and greater potency than reference compounds Oseltamivir and Amantadine against N1-H275Y variant in cellular assays. The structure-activity relationship (SAR) analysis showed that introducing 4-CO2H, 4-OH, 3-OCH3-4-OH substituted benzyl methylene can greatly improve the activity of 4-thiazolinones. Further SAR analysis indicated that 4-thiazolinone and ferulic acid fragments are necessary fragments of target compounds for inhibiting NA. Molecular docking was performed to study the interaction between compound D41 and the active site of NA. This study may providing important information for new drug development for anti-influenza virus including mutant influenza virus.

Kinetically Controllable Pd-Catalyzed Decarboxylation Enabled [5 + 2] and [3 + 2] Cycloaddition toward Carbocycles Featuring Quaternary Carbons.

A decarboxylative protocol has been developed toward a range of carbocycles. The key success is based on the use of a batch of newly designed cyclic carbonates as substrates that can provide carbon-carbon zwitterion intermediate under palladium catalysis. The kinetics of the reactions are controllable toward either strained seven- or thermodynamically more favored five-membered carbocycles. The release of this chemistry will shed light on the synthesis of complex and valuable cyclic structures.

Bioassay of ferulic acid derivatives as influenza neuraminidase inhibitors.

Four series of ferulic acid derivatives were designed, synthesized, and evaluated for their neuraminidase (NA) inhibitory activities against influenza virus H1N1 in vitro. The pharmacological results showed that the majority of the target compounds exhibited moderate influenza NA inhibitory activity, which was also better than that of ferulic acid. The two most potent compounds were 1m and 4a with IC50 values of 12.77 ± 0.47 and 12.96 ± 1.34 µg/ml, respectively. On the basis of the biological results, a preliminary structure-activity relationship (SAR) was derived and discussed. Besides, molecular docking was performed to study the possible interactions of compounds 1p, 2d, 3b, and 4a with the active site of NA. It was found that the 4-OH-3-OMe group and the amide group (CON) of ferulic acid amide derivatives were two key pharmacophores for NA inhibitory activity. It is meaningful to further modify the natural product ferulic acid to improve its influenza NA inhibitory activity.