Global health effects of future atmospheric mercury emissions

Mercury is a potent neurotoxin that poses health risks to the global population. Anthropogenic mercury emissions to the atmosphere are projected to decrease in the future due to enhanced policy efforts such as the Minamata Convention, a legally-binding international treaty entered into force in 2017. Here, we report the development of a comprehensive climate-atmosphere-land-ocean-ecosystem and exposure-risk model framework for mercury and its application to project the health effects of future atmospheric emissions. Our results show that the accumulated health effects associated with mercury exposure during 2010–2050 are $19 (95% confidence interval: 4.7–54) trillion (2020 USD) realized to 2050 (3% discount rate) for the current policy scenario. Our results suggest a substantial increase in global human health cost if emission reduction actions are delayed. This comprehensive modeling approach provides a much-needed tool to help parties to evaluate the effectiveness of Hg emission controls as required by the Minamata Convention

Spatially Constrained Organic Diquat Anolyte for Stable Aqueous Flow Batteries

Redox-active organic materials (ROMs) are becoming increasingly attractive for use in redox flow batteries as promising alternatives to traditional inorganic counterparts. However, the reported ROMs are often accompanied by challenges, including poor solubility and stability. Herein, we demonstrate that the commonly used diquat herbicides, with solubilities of >2 M in aqueous electrolytes, can be used as stable anolyte materials in organic flow batteries. When coupled with a ferrocene-derived catholyte, the flow cells with the diquat anolyte demonstrate long galvanic cycling with high capacity retention. Notably, the mechanistic underpinnings of this remarkable stability are attributed to the improved π-conjugation that originated from the near-planar molecular conformations of the spatially constrained 2,2′-bipyridyl rings, suggesting a viable structural engineering strategy for designing stable organic materials

Annulated Dialkoxybenzenes as Catholyte Materials for Non‐aqueous Redox Flow Batteries: Achieving High Chemical Stability through Bicyclic Substitution

1,4‐Dimethoxybenzene derivatives are materials of choice for use as catholytes in non‐aqueous redox flow batteries, as they exhibit high open‐circuit potentials and excellent electrochemical reversibility. However, chemical stability of these materials in their oxidized form needs to be improved. Disubstitution in the arene ring is used to suppress parasitic reactions of their radical cations, but this does not fully prevent ring‐addition reactions. By incorporating bicyclic substitutions and ether chains into the dialkoxybenzenes, a novel catholyte molecule, 9,10‐bis(2‐methoxyethoxy)‐1,2,3,4,5,6,7,8‐octahydro‐1,4:5,8‐dimethanenoanthracene (BODMA), is obtained and exhibits greater solubility and superior chemical stability in the charged state. A hybrid flow cell containing BODMA is operated for 150 charge–discharge cycles with a minimal loss of capacity.A novel bicyclical substituted dialkoxy‐benzene molecule, 9,10‐bis(2‐methoxy‐ethoxy)‐1,2,3,4,5,6,7,8‐octahydro‐1,4:5,8‐dimethanenoanthracene (BODMA), is developed for use as catholyte materials in non‐aqueous redox flow batteries with greater solubility (in their neutral state) and improved chemical stability (in their charged state). A hybrid flow cell using BODMA demonstrates stable efficiencies and capacity over 150 cycles. The molecular design approach of BODMA can be inspirational for future development of redox active molecules.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139992/1/aenm201701272.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139992/2/aenm201701272-sup-0001-S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139992/3/aenm201701272_am.pd

The lightest organic radical cation for charge storage in redox flow batteries

In advanced electrical grids of the future, electrochemically rechargeable fluids of high energy density will capture the power generated from intermittent sources like solar and wind. To meet this outstanding technological demand there is a need to understand the fundamental limits and interplay of electrochemical potential, stability, and solubility in low-weight redox-active molecules. By generating a combinatorial set of 1,4-dimethoxybenzene derivatives with different arrangements of substituents, we discovered a minimalistic structure that combines exceptional long-term stability in its oxidized form and a record-breaking intrinsic capacity of 161 mAh/g. The nonaqueous redox flow battery has been demonstrated that uses this molecule as a catholyte material and operated stably for 100 charge/discharge cycles. The observed stability trends are rationalized by mechanistic considerations of the reaction pathways.United States. Dept. of Energy. Office of Basic Energy Sciences. Chemical Sciences, Geosciences, & Biosciences Division (Contract DE-AC02-06CH11357

The status of e-learning, personality traits, and coping styles among medical students during the COVID-19 pandemic: a cross-sectional study

ObjectiveThe objective of this study was to explore the learning preferences and habits of medical students during the pandemic home e-learning, and to investigate the incidence of adverse emotions, optimistic character level and coping style. To explore the influencing factors of adverse emotions.MethodsA cross-sectional survey was conducted in China from March to June 2022. Medical students were recruited from three universities in China, and a questionnaire survey was conducted. The questionnaires consisted of a “e-learning preferences and habits questionnaire”, life orientation test questionnaire (LOT-R), and simple coping style questionnaire (SCSQ). Finally, a total of 492 medical students who met the inclusion and exclusion criteria became the research subjects and completed the survey.ResultsA total of 57.7% believed they experienced no adverse emotions during home e-learning. ① During the COVID-19 pandemic, the score of optimistic personality of medical students was (7.25 ± 1.933), and the score of pessimistic personality was (5.82 ± 2.240). The score of positive coping was (21.75 ± 5.379), and the score of negative coping was (11.75 ± 3.611). ② The occurrence of medical students' adverse emotions during e-learning was influenced by “Whether there is a private, quiet space to study”, “Degree of knowledge mastery”, “Physical discomfort or not”, “Keep a regular schedule or not”, “Optimistic personality tendency”.ConclusionThis study demonstrates the during home e-learning, most medical students have their own learning equipment and can meet their learning needs. Their favorite mobile device to use is a mobile phone, and their favorite method of teaching is to provide course playback. More than half of medical students believe that they have some inconvenience in conducting research during home e-learning. With regard to teacher's real-time screen, the largest number of medical students support teachers turning on live screens so that they feel like they are interacting with the teacher. The preference for blended teaching is highest among medical students. In general, medical students were highly adaptive of the newest e-learning approach. Based on the statistic analysis, the factors that “Whether there is a private, quiet space to study”, “Degree of knowledge mastery”, “Physical discomfort or not”, “Keep a regular schedule or not”, and “Optimistic personality tendency” may be the influencing factors for the occurrence of adverse emotions

Effect of the Hydrofluoroether Cosolvent Structure in Acetonitrile-Based Solvate Electrolytes on the Li^+ Solvation Structure and Li–S Battery Performance

We evaluate hydrofluoroether (HFE) cosolvents with varying degrees of fluorination in the acetonitrile-based solvate electrolyte to determine the effect of the HFE structure on the electrochemical performance of the Li–S battery. Solvates or sparingly solvating electrolytes are an interesting electrolyte choice for the Li–S battery due to their low polysulfide solubility. The solvate electrolyte with a stoichiometric ratio of LiTFSI salt in acetonitrile, (MeCN)_2–LiTFSI, exhibits limited polysulfide solubility due to the high concentration of LiTFSI. We demonstrate that the addition of highly fluorinated HFEs to the solvate yields better capacity retention compared to that of less fluorinated HFE cosolvents. Raman and NMR spectroscopy coupled with ab initio molecular dynamics simulations show that HFEs exhibiting a higher degree of fluorination coordinate to Li+ at the expense of MeCN coordination, resulting in higher free MeCN content in solution. However, the polysulfide solubility remains low, and no crossover of polysulfides from the S cathode to the Li anode is observed