A fundamental study on selective extraction of Li+ with dibenzo-14-crown-4 ether: Toward new technology development for lithium recovery from brines.

The present study has proposed a selective Li+ extraction process using a novel extractant of dibenzo-14-crown-4 ether functionalized with an alkyl C16 chain (DB14C4-C16) synthesized based on the ion imprinting technology (IIT). Theoretical analysis of the possible complexes formed by DB14C4-C16 with Li+ and the competing ions of Na+, K+, Ca2+ and Mg2+ was performed through density functional theory (DFT) modeling. The Gibbs free energy change of the complexes of metal ions with DB14C4-C16 and water molecules were calculated to be -125.81 and -166.01 kJ/mol for lithium, -55.73 and -117.77 kJ/mol for sodium, and -196.02 and -291.52 kJ/mol for magnesium, respectively. Furthermore, the solvent extraction experiments were carried out in both single Li+ and multi-ions containing solutions, and the results delivered a good selectivity of DB14C4-C16 towards Li+ over the competing ions, showing separation coefficients of 68.09 for Ca2+-Li+, 24.53 for K+-Li+, 16.32 for Na+-Li+, and 3.99 for Mg2+-Li+ under the optimal conditions. The experimental results are generally in agreement with the theoretical calculations.

Comparison of Lasmiditan 200 mg Versus 100 mg for Migraine Patients: A Meta-analysis of Randomized Controlled Studies.

INTRODUCTION: The ideal dose of lasmiditan for migraine is not clear. This meta-analysis aims to compare the efficacy of lasmiditan 200 mg versus 100 mg for migraine patients. METHODS: We have searched several databases including PubMed, Embase, Web of Science, EBSCO, and Cochrane Library Databases and selected the randomized controlled trials comparing the efficacy of lasmiditan 200 mg versus 100 mg for migraine patients. This meta-analysis was conducted using the random-effect model. RESULTS: Five randomized controlled trials were included in this meta-analysis. Compared with lasmiditan 100-mg group in migraine patients, lasmiditan 200-mg group was associated with substantially increased pain free at 2 hours (odds ratio [OR], 1.27; 95% confidence interval [CI], 1.12-1.44; P = 0.0002) and pain free at 24 hours (OR, 1.31; 95% CI, 1.08-1.60; P = 0.007) but demonstrated no obvious impact on pain relief at 2 hours (OR, 1.02; 95% CI, 0.91-1.16; P = 0.72) or MBS free at 2 hours (OR, 0.94; 95% CI, 0.77-1.14; P = 0.52). In addition, the incidence of adverse events was higher in lasmiditan 200-mg group than that in lasmiditan 100-mg group (OR, 1.29; 95% CI, 1.15-1.45; P < 0.0001). CONCLUSIONS: Lasmiditan 200 mg is better for the treatment of migraine patients than lasmiditan 100 mg.

Interaction and selectivity of 14-crown-4 derivatives with Li+, Na+, and Mg2+ metal ions.

The interactions between crown ether ligands (14-crown-4, 14C4; 4,4,5,5-tetramethylbenzo-14-crown-4, BC4H12-14C4; 4,4,5,5,9,9,10,10-octamethyl-14-crown-4, C8H24-14C4; dibenzo-14-crown ether-4, DB14C4) and alkaline and alkaline earth metal ions (Li+, Na+, Mg2+) were investigated using density functional theory modeling at the M062X/def2SVP and def2TZVP level. The condensed softness analysis of crown ethers, a condensed Fukui function, a condensed dual descriptor, and frontier molecular orbital theory were used to analyze the reactivities of the complexes. The complex stability was analyzed in terms of the binding energies, standard Gibbs free energy of formation, and energy decomposition of the interaction in aqueous solution. The results show that the active sites were mainly located at the carbon atoms of the benzene ring and oxygen atoms. The reactivities of DB14C4 and BC4H12-14C4 are higher than those of 14C4 and C8H24-14C4. The electrostatic interaction is the principal factor determining the stability of the complexes. The complexes containing Li+ has the greatest stability in aqueous solution among the complexes containing Li+, Na+, and Mg2+. BC4H12-14C4 shows selective adsorption toward Li+ in a mixed solution of Li+, Na+, and Mg2+. To evaluate the stability of complexes containing Mg2+, the solvent effect must be accurately described. An energy decomposition analysis was used to evaluate the stability of complexes containing Li+, Na+, and Mg2+, and the solvent effects were considered.

Adsorptive removal of trace thallium(I) from wastewater: A review and new perspectives.

Thallium is an emerging pollutant reported in wastewater along with the increasing mining and smelting of thallium-containing ores in recent years. The complete removal of Tl(I) from wastewater is of significant emergency due to its high toxicity and mobility, however, Tl(I) removal is always confronted with numerous technical difficulties because of the extremely low Tl(I) concentration in wastewater and the disturbances of many accompanying impurity ions. Adsorption is currently the most widely used method for Tl(I) removal on industrial scale and varied kinds of adsorbents such as Prussian blue analogues, biosorbents, and metal oxides have been developed. However, the adsorption process of Tl(I) is always affected by the co-existing cations, resulting in low Tl(I) removal efficiency. Recently, the development of a variety of novel adsorbents or ion sensors based on macrocyclic compounds for enrichment and accurate determination of trace Tl(I) in aqueous solutions exhibits great potential for application in Tl(I) removal from wastewater with high selectivity and process efficiency. This paper provides an overview of the adsorption methods for Tl(I) removal from wastewater with emphasis on complexation properties between varied types of adsorbents and Tl(I). Future directions of research and development of adsorptive Tl(I) removal from industrial wastewater are proposed.