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The dielectric constant is a critical parameter in many energy-related applications. Typically, increasing the dielectric constant of soft materials involves adding high dielectric constant polar liquids or inorganic fillers, but there are limitations to this approach due to safety concerns with volatile and flammable solvents and the agglomeration of inorganic fillers. An alternative approach is to add zwitterionic liquids that exhibit exceptionally high dielectric constants with negligible volatility. Here, we report the synthesis of a series of zwitterionic liquids containing an imidazolium cation, exhibiting the highest dielectric constant among all organic molecules (∼350 at 293 K). The cation–anion linkage was tailored in a wide range between three and nine carbons, rendering the zwitterion dipole from 25 to 52 D. Comparing the dielectric constant for zwitterions with different anions (i.e., sulfonylimide, sulfonate, and carboxylate) reveals the beneficial impacts of the delocalized sulfonylimide anion vs the carboxylate anion due to the enlarged molecular dipole and more homogenous liquid morphology. Molecular dipole and liquid morphology are identified as the keys to developing high dielectric constant zwitterionic liquids. The extremely high dielectric constant accessible with the proposed molecular design paves new avenues for developing high dielectric constant zwitterions that act as dielectricizers. [ABSTRACT FROM AUTHOR]

Single ion conducting gel polymer electrolytes (GPEs) are characterized as having a certain amount of ionic liquid or solvent incorporated into a single ion-conducting polymer matrix and may afford the advantages of high conductivity and low electrolyte polarization under battery operation. Single ion conducting polymers often suffer from low conductivity due to their reliance on polymer segmental motion to achieve sufficient ion mobility. However, by incorporating specific solvents into a single ion conducting matrix, mobility of the polymer can be enhanced while still maintaining the advantages of single ion conduction. Although many of the solvents used to swell GPEs are mixtures of flammable organic solvents (such as dimethyl carbonate), there are many potential non-reactive, low vapor pressure solvents that could effectively solvate alkali-ion based GPEs and plasticize the polymer matrix to enhance ion conductivity. Adipate-based solvents are a group of non-volatile plasticizers with low viscosities and low vapor pressures at room temperature derived from adipic acid. The ester groups in these solvents may effectively solvate alkali ions such as Na+, leading to higher conductivity, while circumventing issues of flammability found in current alkali-ion conducting electrolytes. This study investigates the properties of sodium-ion conducting GPEs that have been swollen with varying adipate-based solvents and the subsequent dielectric response from the solvent addition. Dielectric relaxation spectroscopy was used to characterize the Na+ conductivity, static dielectric constant, ion-conducting content, and mobility of the membranes before and after the non-volatile solvent uptake. Understanding this relationship will pave the path toward safer, more efff cient solid-state polymer electrolytes for battery applications. [ABSTRACT FROM AUTHOR]

Materials with high dielectric constant, εs, are desirable in a wide range of applications including energy storage and actuators. Recently, zwitterionic liquids have been reported to have the largest εs of any liquid and, thus, have the potential to replace inorganic fillers to modulate the material εs. Although the large εs for zwitterionic liquids is attributed to their large molecular dipole, the role of chemical substituents attached to the zwitterion cation on εs is not fully understood, which is necessary to enhance the performance of soft energy materials. Here, we report the impact of zwitterionic liquid cation chemical substituents on εs (50 < εs < 300 at room temperature). Dielectric relaxation spectroscopy reveals that molecular reorientation is the main contributor to the high εs. The low Kirkwood factor g calculated for zwitterionic liquids (e.g., 0.1–0.2) suggests the tendency for the antiparallel zwitterion dipole alignment expected from the strong electrostatic intermolecular interactions. With octyl cation substituents, the g is decreased due to the formation of hydrophobic-rich domains that restrict molecular reorientation under applied electric fields. In contrast, when zwitterion cations are functionalized with ethylene oxide (EO) segments, g increases due to the EO segments interacting with the cations, allowing more zwitterion rotation in response to the applied field. The reported results suggest that high εs zwitterionic liquids require a large molecular dipole, compositionally homogeneous liquids (e.g., no aggregation), a maximized zwitterion number density, and a high g, which is achievable by incorporating polar chemical substituents onto the zwitterion cations. [ABSTRACT FROM AUTHOR]

Background Lingering symptoms have been reported by survivors of Ebola virus disease (EVD). There are few data describing the persistence and severity of these symptoms over time. Methods Symptoms of headache, fatigue, joint pain, muscle pain, hearing loss, visual loss, numbness of hands or feet were longitudinally assessed among participants in the Liberian Ebola Survivors Cohort study. Generalized linear mixed effects models, adjusted for sex and age, were used to calculate the odds of reporting a symptom and it being rated as highly interfering with life. Results From June 2015 to June 2016, 326 survivors were enrolled a median of 389 days (range 51–614) from acute EVD. At baseline 75.2% reported at least 1 symptom; 85.8% were highly interfering with life. Over a median follow-up of 5.9 years, reporting of any symptom declined (odds ratio for each 90 days of follow-up = 0.96, 95% confidence interval [CI]:.95,.97; P <.0001) with all symptoms declining except for numbness of hands or feet. Rating of any symptom as highly interfering decreased over time. Among 311 with 5 years of follow-up, 52% (n = 161) reported a symptom and 29% (n = 47) of these as highly interfering with their lives. Conclusions Major post-EVD symptoms are common early during convalescence and decline over time along with severity. However, even 5 years after acute infection, a majority continue to have symptoms and, for many, these continue to greatly impact their lives. These findings call for investigations to identify the mechanisms of post-EVD sequelae and therapeutic interventions to benefit the thousands of effected EVD survivors. [ABSTRACT FROM AUTHOR]

Circadian rhythms are oscillations of behavior, physiology and metabolism in many organisms. Recent advancements in omics technology make it possible for genome-wide profiling of circadian rhythms. Here, we conducted a comprehensive analysis of seven existing algorithms commonly used for circadian rhythm detection. Using gold-standard circadian and non-circadian genes, we systematically evaluated the accuracy and reproducibility of the algorithms on empirical datasets generated from various omics platforms under different experimental designs. We also carried out extensive simulation studies to test each algorithm's robustness to key variables, including sampling patterns, replicates, waveforms, signal-to-noise ratios, uneven samplings and missing values. Furthermore, we examined the distributions of the nominal |$P$| -values under the null and raised issues with multiple testing corrections using traditional approaches. With our assessment, we provide method selection guidelines for circadian rhythm detection, which are applicable to different types of high-throughput omics data. [ABSTRACT FROM AUTHOR]

Nitroxide-mediated controlled radical polymerization of 2-hydroxyethyl methacrylate (HEMA) is achieved using the copolymerization method with a small initial concentration of acrylonitrile (AN, 5-16 mol%)) or styrene (S, 5-10 mol%). The polymerization is mediated by N- tert-butyl- N-(1-diethyl phosphono-2,2-dimethyl propyl) nitroxide (SG1)-based BlocBuilder unimolecular alkoxyamine initiator modified with an N-succinimidyl ester group ( N-hydroxysuccinimide-BlocBuilder). As little as 5% molar feed of acrylonitrile results in a controlled polymerization, as evidenced by a linear increase in number average molecular weight Mn with conversion and dispersities ( Đ) as low as 1.30 at 80% conversion in N, N-dimethylformamide (DMF) at 85 °C. With S as the controlling comonomer, higher initial S composition (≈10 mol%) is required to maintain the controlled copolymerization. Poly(HEMA- ran-AN)s with Mn ranging from 5 to 20 kg mol−1 are efficiently chain extended using n-butyl methacrylate/styrene mixtures at 90.0 °C in DMF, thereby showing a route to HEMA-based amphiphilic block copolymers via nitroxide-mediated polymerization. [ABSTRACT FROM AUTHOR]

Front Cover: Nitroxide mediated polymerization (NMP) with SG1/based initiators is used to prepare hydroxyethyl methacrylate (HEMA)‐rich copolymers using a small fraction ≈ 10 mol% of co‐monomer, acrylonitrile (AN). HEMA/AN copolymerizations exhibit linear degree of polymerization versus conversion with low dispersity (Đ = 1.3‐1.4) and good chain end fidelity. Further details can be found in the article by Wenwen Mei, and Milan Maric, article number 1600067. [ABSTRACT FROM AUTHOR]