Solid-state rigid-rod polymer composite electrolytes with nanocrystalline lithium ion pathways.

A critical challenge for next-generation lithium-based batteries lies in development of electrolytes that enable thermal safety along with the use of high-energy-density electrodes. We describe molecular ionic composite electrolytes based on an aligned liquid crystalline polymer combined with ionic liquids and concentrated Li salt. This high strength (200 MPa) and non-flammable solid electrolyte possesses outstanding Li+ conductivity (1 mS cm-1 at 25 °C) and electrochemical stability (5.6 V versus Li|Li+) while suppressing dendrite growth and exhibiting low interfacial resistance (32 Ω cm2) and overpotentials (≤120 mV at 1 mA cm-2) during Li symmetric cell cycling. A heterogeneous salt doping process modifies a locally ordered polymer-ion assembly to incorporate an inter-grain network filled with defective LiFSI and LiBF4 nanocrystals, strongly enhancing Li+ conduction. This modular material fabrication platform shows promise for safe and high-energy-density energy storage and conversion applications, incorporating the fast transport of ceramic-like conductors with the superior flexibility of polymer electrolytes.

Cross-sectional associations between domain-specific sitting time and other lifestyle health behaviours: the Stormont study.

BACKGROUND: There is a dearth of literature on how different domains of sitting time relate to other health behaviours. Therefore, this study aimed to explore these associations in a sample of office workers. METHODS: 7170 Northern Irish Civil Servants completed an online survey which included information on workday and non-workday sitting time in five domains (travel, work, TV, computer-use, leisure-time), physical activity, fruit and vegetable intake, alcohol consumption and cigarette smoking. An unhealthy behaviour score was calculated by summing the number of health behaviours which did not meet the current guidelines. Multinomial regressions examined associations between unhealthy behaviour score and each domain of sitting time. RESULTS: ≥7 hours sitting at work and ≥2 hours TV viewing on a workday both more than doubled the odds of partaking in ≥3 unhealthy behaviours [Odds ratio, OR = 2.03, 95% CI, (1.59-2.61); OR = 2.19 (1.71-2.80)] and ≥3 hours of TV viewing on a non-workday nearly tripled the odds [OR = 2.96 (2.32-3.77)]. CONCLUSIONS: High sitting time at work and TV viewing on a workday and non-workday are associated with increased odds of partaking in multiple unhealthy behaviours. Interventions need to focus on these domains and public health policy should consider sitting time as an important health behaviour.

Computer-assisted EEG diagnostic review for idiopathic generalized epilepsy.

Epilepsy diagnosis can be costly, time-consuming, and not uncommonly inaccurate. The reference standard diagnostic monitoring is continuous video-electroencephalography (EEG) monitoring, ideally capturing all events or concordant interictal discharges. Automating EEG data review would save time and resources, thus enabling more people to receive reference standard monitoring and also potentially heralding a more quantitative approach to therapeutic outcomes. There is substantial research into the automated detection of seizures and epileptic activity from EEG. However, automated detection software is not widely used in the clinic, and despite numerous published algorithms, few methods have regulatory approval for detecting epileptic activity from EEG. This study reports on a deep learning algorithm for computer-assisted EEG review. Deep convolutional neural networks were trained to detect epileptic discharges using a preexisting dataset of over 6000 labelled events in a cohort of 103 patients with idiopathic generalized epilepsy (IGE). Patients underwent 24-hour ambulatory outpatient EEG, and all data were curated and confirmed independently by two epilepsy specialists (Seneviratne et al., 2016). The resulting automated detection algorithm was then used to review diagnostic scalp EEG for seven patients (four with IGE and three with events mimicking seizures) to validate performance in a clinical setting. The automated detection algorithm showed state-of-the-art performance for detecting epileptic activity from clinical EEG, with mean sensitivity of >95% and corresponding mean false positive rate of 1 detection per minute. Importantly, diagnostic case studies showed that the automated detection algorithm reduced human review time by 80%-99%, without compromising event detection or diagnostic accuracy. The presented results demonstrate that computer-assisted review can increase the speed and accuracy of EEG assessment and has the potential to greatly improve therapeutic outcomes. This article is part of the Special Issue "NEWroscience 2018".

Cation effect on small phosphonium based ionic liquid electrolytes with high concentrations of lithium salt.

Ionic liquid electrolytes with high alkali salt concentrations have displayed some excellent electrochemical properties, thus opening up the field for further improvements to liquid electrolytes for lithium or sodium batteries. Fundamental computational investigations into these high concentration systems are required in order to gain a better understanding of these systems, yet they remain lacking. Small phosphonium-based ionic liquids with high concentrations of alkali metal ions have recently shown many promising results in experimental studies, thereby prompting us to conduct further theoretical exploration of these materials. Here, we conducted a molecular dynamics simulation on four small phosphonium-based ionic liquids with 50 mol. % LiFSI salt, focusing on the effect of cation structure on local structuring and ion diffusional and rotational dynamics-which are closely related to the electrochemical properties of these materials.

Descriptive epidemiology of domain-specific sitting in working adults: the Stormont Study.

BACKGROUND: Given links between sedentary behaviour and unfavourable health outcomes, there is a need to understand the influence of socio-demographic factors on sedentary behaviour to inform effective interventions. This study examined domain-specific sitting times reported across socio-demographic groups of office workers. METHODS: The analyses are cross-sectional and based on a survey conducted within the Stormont Study, which is tracking employees in the Northern Ireland Civil Service. Participants self-reported their daily sitting times across multiple domains (work, TV, travel, PC use and leisure) on workdays and non-workdays, along with their physical activity and socio-demographic variables (sex, age, marital status, BMI, educational attainment and work pattern). Total and domain-specific sitting on workdays and non-workdays were compared across socio-demographic groups using multivariate analyses of covariance. RESULTS: Completed responses were obtained from 4436 participants. For the whole sample, total daily sitting times were higher on workdays in comparison to non-workdays (625 ± 168 versus 469 ± 210 min/day, P < 0.001). On workdays and non-workdays, higher sitting times were reported by individuals aged 18-29 years, obese individuals, full-time workers and single/divorced/widowed individuals (P < 0.001). CONCLUSIONS: Interventions are needed to combat the high levels of sedentary behaviour observed in office workers, particularly among the highlighted demographic groups. Interventions should target workplace and leisure-time sitting.

Lessons from 150 years of UK maternal hemorrhage deaths.

We have reviewed maternal hemorrhage death rates in the UK over the past 150 years in order to draw lessons from this material for current attempts to reduce global maternal mortality. Mortality rates from data in the UK Annual Reports from the Registrar General were entered into a database. Charts were created to display trends in hemorrhage mortality, allowing comparison with historical medical advances. Hemorrhage death rates fell steadily before the 1930s; between 1874 and 1926 they fell by 56%. In contrast, there was no consistent reduction in overall maternal mortality rates until the 1930s; from 1932 to 1952 they fell by 85%, primarily due to a reduction in sepsis deaths. In conclusion the majority of maternal hemorrhage mortality reductions in the UK occurred prior to the availability of effective oxytocics, antibiotics, and blood transfusion. Improving access to and standards of maternal care is key to addressing global maternal mortality today.

Work engagement and its association with occupational sitting time: results from the Stormont study.

BACKGROUND: Evidence suggests that poor health outcomes and poor work-related health outcomes such as sickness presenteeism are associated with excessive sitting at work. Studies have yet to investigate the relationship between work engagement and occupational sitting. Work engagement is considered to be an important predictor of work-related well-being. We investigated the relationship between and self-reported work engagement and high occupational sitting time in Northern Ireland Civil Service (NICS) office-based workers. METHOD: A cohort of 4436 NICS office-workers (1945 men and 2491 women) completed a questionnaire measuring work engagement and occupational sitting time. Logistic regression analyses were used to test the associations between work engagement and occupational sitting times. RESULTS: Compared to women, men reported lower mean occupational sitting time (385.7 minutes/day; s.d. = 1.9; versus 362.4 minutes/day; s.d. =2.5; p < .0001). After adjusting for confounding variables, men with high work engagement of vigor (OR = 0.49, 95% CI 0.34-0.98) and dedication (OR 0.68 95% CI 0.47-0.98) were less likely to have prolonged sitting time. Women with high work engagement of vigor (OR = 0.62, 95% CI 0.45-0.84) were also less likely to have prolonged occupational sitting times. In contrast, women with high absorption (OR = 1.29, 95% CI 1.01-1.65) were more likely to have prolonged sitting times. CONCLUSIONS: Being actively engaged in one's work is associated with lower occupational sitting times for men (vigor and dedication) and to a limited extent for women (vigor only). This suggests that interventions such as introducing sit-stand workstations to reduce sitting times, may be beneficial for work engagement.

Delay selection by spike-timing-dependent plasticity in recurrent networks of spiking neurons receiving oscillatory inputs.

Learning rules, such as spike-timing-dependent plasticity (STDP), change the structure of networks of neurons based on the firing activity. A network level understanding of these mechanisms can help infer how the brain learns patterns and processes information. Previous studies have shown that STDP selectively potentiates feed-forward connections that have specific axonal delays, and that this underlies behavioral functions such as sound localization in the auditory brainstem of the barn owl. In this study, we investigate how STDP leads to the selective potentiation of recurrent connections with different axonal and dendritic delays during oscillatory activity. We develop analytical models of learning with additive STDP in recurrent networks driven by oscillatory inputs, and support the results using simulations with leaky integrate-and-fire neurons. Our results show selective potentiation of connections with specific axonal delays, which depended on the input frequency. In addition, we demonstrate how this can lead to a network becoming selective in the amplitude of its oscillatory response to this frequency. We extend this model of axonal delay selection within a single recurrent network in two ways. First, we show the selective potentiation of connections with a range of both axonal and dendritic delays. Second, we show axonal delay selection between multiple groups receiving out-of-phase, oscillatory inputs. We discuss the application of these models to the formation and activation of neuronal ensembles or cell assemblies in the cortex, and also to missing fundamental pitch perception in the auditory brainstem.

Understanding the Capacity Decay of Si/NMC622 Li-Ion Batteries Cycled in Superconcentrated Ionic Liquid Electrolytes: A New Perspective.

Silicon-containing Li-ion batteries have been the focus of many energy storage research efforts because of the promise of high energy density. Depending on the system, silicon generally demonstrates stable performance in half-cells, which is often attributed to the unlimited lithium supply from the lithium (Li) metal counter electrode. Here, the electrochemical performance of silicon with a high voltage NMC622 cathode was investigated in superconcentrated phosphonium-based ionic liquid (IL) electrolytes. As a matter of fact, there is very limited work and understanding of the full cell cycling of silicon in such a new class of electrolytes. The electrochemical behavior of silicon in the various IL electrolytes shows a gradual and steeper capacity decay, compared to what we previously reported in half-cells. This behavior is linked to a different evolution of the silicon morphology upon cycling, and the characterization of cycled electrodes points toward mechanical reasons, complete disconnection of part of the electrode, or internal mechanical stress, due to silicon and Li metal volume variation upon cycling, to explain the progressive capacity fading in full cell configuration. An extremely stable solid electrolyte interphase (SEI) in the full Li-ion cells can be seen from a combination of qualitative and quantitative information from transmission electron microscopy, X-ray photoelectron spectroscopy, electrochemical impedance spectroscopy, and magic angle spinning nuclear magnetic resonance. Our findings provide a new perspective to full cell interpretation regarding capacity fading, which is oftentimes linked almost exclusively to the loss of Li inventory but also more broadly, and provide new insights into the impact of the evolution of silicon morphology on the electrochemical behavior.

Current Treatment Approaches and Global Consensus Guidelines for Brain Metastases in Melanoma.

Background: Up to 60% of melanoma patients develop melanoma brain metastases (MBM), which traditionally have a poor diagnosis. Current treatment strategies include immunotherapies (IO), targeted therapies (TT), and stereotactic radiosurgery (SRS), but there is considerable heterogeneity across worldwide consensus guidelines. Objective: To summarize current treatments and compare worldwide guidelines for the treatment of MBM. Methods: Review of global consensus treatment guidelines for MBM patients. Results: Substantial evidence supported that concurrent IO or TT plus SRS improves progression-free survival (PFS) and overall survival (OS). Guidelines are inconsistent with regards to recommendations for surgical resection of MBM, since surgical resection of symptomatic lesions alleviates neurological symptoms but does not improve OS. Whole-brain radiation therapy is not recommended by all guidelines due to negative effects on neurocognition but can be offered in rare palliative scenarios. Conclusion: Worldwide consensus guidelines consistently recommend up-front combination IO or TT with or without SRS for the treatment of MBM.

Morphological Evolution and Solid-Electrolyte Interphase Formation on LiNi0.6Mn0.2Co0.2O2 Cathodes Using Highly Concentrated Ionic Liquid Electrolytes.

Employing high-voltage Ni-rich cathodes in Li metal batteries (LMBs) requires stabilization of the electrode/electrolyte interfaces at both electrodes. A stable solid-electrolyte interphase (SEI) and suppression of active material pulverization remain the greatest challenges to achieving efficient long-term cycling. Herein, studies of NMC622 (1 mAh cm-2) cathodes were performed using highly concentrated N-methyl-N-propylpyrrolidinium bis(fluorosulfonyl)imide (C3mpyrFSI) 50 mol % lithium bis(fluorosulfonyl)imide (LiFSI) ionic liquid electrolyte (ILE). The resulting SEI formed at the cathode enabled promising cycling performance (98.13% capacity retention after 100 cycles), and a low degree of ion mixing and lattice expansion was observed, even at an elevated temperature of 50 °C. Fitting of acquired impedance spectra indicated that the SEI resistivity (RSEI) had a low and stable contribution to the internal resistivity of the system, whereas active material pulverization and secondary grain isolation significantly increased the charge transfer resistance (RCT) throughout cycling.

Highly stable lithium anodes from recycled hemp textile.

Three-dimensional lithium (Li) hosts have been shown to suppress the growth of Li dendrites for next generation Li metal batteries. Here, we report a cost-effective and scalable approach to produce highly stable Li composite anodes from industrial hemp textile waste. The hemp@Li composite anodes demonstrate stable cycling both in half and full cells.

Traveling Ionospheric Disturbances in the Vicinity of Storm-Enhanced Density at Midlatitudes.

This study provides first storm time observations of the westward-propagating medium-scale traveling ionospheric disturbances (MSTIDs), particularly, associated with characteristic subauroral storm time features, storm-enhanced density (SED), subauroral polarization stream (SAPS), and enhanced thermospheric westward winds over the continental US. In the four recent (2017-2019) geomagnetic storm cases examined in this study (i.e., 2018-08-25/26, 2017-09-07/08, 2017-05-27/28, and 2016-02-02/03 with minimum SYM-H index -206, -146, -142, and -58 nT, respectively), MSTIDs were observed from dusk-to-midnight local times predominately during the intervals of interplanetary magnetic field (IMF) Bz stably southward. Multiple wavefronts of the TIDs were elongated NW-SE, 2°-3° longitude apart, and southwestward propagated at a range of zonal phase speeds between 100 and 300 m/s. These TIDs initiated in the northeastern US and intensified or developed in the central US with either the coincident SED structure (especially the SED basis region) or concurrent small electron density patches adjacent to the SED. Observations also indicate coincident intense storm time electric fields associated with the magnetosphere-ionosphere-thermosphere coupling electrodynamics at subauroral latitudes (such as SAPS) as well as enhanced thermospheric westward winds. We speculate that these electric fields trigger plasma instability (with large growth rates) and MSTIDs. These electrified MSTIDs propagated westward along with the background westward ion flow which resulted from the disturbance westward wind dynamo and/or SAPS.

Vortex stretching as a mechanism for quantum kinetic energy decay.

A pair of perturbed antiparallel quantum vortices, simulated using the three-dimensional Gross-Pitaevskii equations, is shown to be unstable to vortex stretching. This results in kinetic energy K(∇ψ) being converted into interaction energy E(I) and eventually local kinetic energy depletion that is similar to energy decay in a classical fluid, even though the governing equations are Hamiltonian and energy conserving. The intermediate stages include the generation of vortex waves, their deepening, multiple reconnections, the emission of vortex rings and phonons, and the creation of an approximately -5/3 kinetic energy spectrum at high wave numbers. All of the wave generation and reconnection steps follow from interactions between the two original vortices. A four vortex example is given to demonstrate that some of these steps might be general.

Tuning the Formation and Structure of the Silicon Electrode/Ionic Liquid Electrolyte Interphase in Superconcentrated Ionic Liquids.

The latest advances in the stabilization of Li/Na metal battery and Li-ion battery cycling have highlighted the importance of electrode/electrolyte interface [solid electrolyte interphase (SEI)] and its direct link to cycling behavior. To understand the structure and properties of the SEI, we used combined experimental and computational studies to unveil how the ionic liquid (IL) cation nature and salt concentration impact the silicon/IL electrolyte interfacial structure and the formed SEI. The nature of the IL cation is found to be important to control the electrolyte reductive decomposition that influences the SEI composition and properties and the reversibility of the Li-Si alloying process. Also, increasing the Li salt concentration changes the interface structure for a favorable and less resistive SEI. The most promising interface for the Si-based battery was found to be in P1222FSI with 3.2 m LiFSI, which leads to an optimal SEI after 100 cycles in which LiF and trapped LiFSI are the only distinguishable lithiated and fluorinated products detected. This study shows a clear link between the nanostructure of the IL electrolyte near the electrode surface, the resulting SEI, and the Si negative electrode cycling performance. More importantly, this work will aid the rational design of Si-based Li-ion batteries using IL electrolytes in an area that has so far been neglected, reinforcing the benefits of superconcentrated electrolyte systems.

Phase II clinical trial of paclitaxel loaded polymeric micelle in patients with advanced pancreatic cancer.

PURPOSE: To determine in patients, with locally advanced or metastatic pancreatic cancer (APC), efficacy and safety of treatment with intravenous paclitaxel loaded polymeric micelle (GPM). PATIENTS AND METHODS: This was a multicenter, open-label Phase II study. Patients with APC, ECOG performance status < or = 2, no prior chemotherapy and adequate organ function were treated with 3-hour GPM infusions every 3 weeks. Initial patients were treated with 435 mg/m(2) (n = 11). The dose was reduced for subsequent patients to 350 or 300 mg/m(2) (n = 45). Primary endpoint was time to tumor progression (TTP). RESULTS: 56 patients were enrolled. Median TTP for patients treated with 300 or 350 mg/m(2) doses was 3.2 months (95% CI, 2.6-4.2). Median progression free survival (PFS) was 2.8 months (95% CI, 1.4-4.0). Median overall survival (OS) was 6.5 months (95% CI, 5.1-7.9). Among patients treated with above doses of GPM, there was 1 complete remission (CR) and 2 partial remissions (PR) with an overall response rate (ORR) of 6.7%. Disease control rate (CR + PR + stable disease) was 60.0%. Most common grade 3 toxicities were: neutropenia (40.0%), fatigue (17.8%), infection, dehydration, neuropathy (each 13.3%), and abdominal pain (11.1%). CONCLUSIONS: Treatment of APC with GPM at a dose of 300 mg/m(2) q 3 weeks was well tolerated and common toxicities were qualitatively similar to Cremophor-based paclitaxel. GPM monotherapy resulted in OS and other efficacy parameters preferable to that seen historically with gemcitabine. Future studies of GPM in combination with other agents for treatment of APC are warranted.

Compressively Stressed Silicon Nanoclusters as an Antifracture Mechanism for High-Performance Lithium-Ion Battery Anodes.

Silicon has been considered a good candidate for replacing the commonly used carbon anodes for lithium-ion batteries (LIBs) due to its high specific capacity, which can be up to 11 times higher than that of carbon. However, the desirable advantage that silicon brings to battery performance is currently overshadowed by its stress-induced performance loss and high electronic resistivity. The induced stress arises from two sources, namely, the deposition process (i.e., residual stress) during fabrication and the volume expansion (i.e., mechanical stress) associated with the lithiation/delithiation process. Of the two, residual stress has largely been ignored, underestimated, or considered to have a negligible effect without any rigorous evidence being put forward. In this contribution, we produced silicon thin films having a wide range of residual stress and resistivity using a physical vapor deposition technique, magnetron sputtering. Three pairs of silicon thin-film anodes were utilized to study the effect of residual stress on the electrochemical and cyclability performance as anodes for LIBs. Each set consisted of a pair of films having essentially the same resistivity, density, thickness, and oxidation amount but distinctly different residual stresses. The comparison was evaluated by conducting charge/discharge cycling and cyclic voltammetry (CV) experiments. In contrast to the fixed belief within the literature, higher compressive residual-stress films showed better electrochemical and cycle performance compared to lower residual-stress films. The results, herein, present an informed understanding of the role that residual stress plays, which will help researchers improve the development of silicon-based thin-film anodes.

Toward High-Energy-Density Lithium Metal Batteries: Opportunities and Challenges for Solid Organic Electrolytes.

With increasing demands for safe, high capacity energy storage to support personal electronics, newer devices such as unmanned aerial vehicles, as well as the commercialization of electric vehicles, current energy storage technologies are facing increased challenges. Although alternative batteries have been intensively investigated, lithium (Li) batteries are still recognized as the preferred energy storage solution for the consumer electronics markets and next generation automobiles. However, the commercialized Li batteries still have disadvantages, such as low capacities, potential safety issues, and unfavorable cycling life. Therefore, the design and development of electromaterials toward high-energy-density, long-life-span Li batteries with improved safety is a focus for researchers in the field of energy materials. Herein, recent advances in the development of novel organic electrolytes are summarized toward solid-state Li batteries with higher energy density and improved safety. On the basis of new insights into ionic conduction and design principles of organic-based solid-state electrolytes, specific strategies toward developing these electrolytes for Li metal anodes, high-energy-density cathode materials (e.g., high voltage materials), as well as the optimization of cathode formulations are outlined. Finally, prospects for next generation solid-state electrolytes are also proposed.

Macrophase-Separated Organic Ionic Plastic Crystals/PAMPS-Based Ionomer Electrolyte: A New Design Perspective for Flexible and Highly Conductive Solid-State Electrolytes.

A material design approach was taken for the preparation of an organic ionic plastic crystal (OIPC)-polymer electrolyte material that exhibited both good mechanical and transport properties. Previous attempts to form this type of electrolyte material resulted in the solvation of the OIPC by the ionomer and loss of the plastic crystal component. Here, we prepared, in situ, a macrophase-separated OIPC-polymer electrolyte system by adding lithium bis(fluorosulfonyl)imide (LiFSI) to a (PAMPS-N1222) ionomer. It was found that an optimal compositional window of 40-50 mol % LiFSI exists whereby the electrolyte conductivity suddenly increased 4 orders of magnitude while exhibiting elastic and flexible mechanical properties. The phase behavior and transport properties were studied using differential scanning calorimetry and 7Li and 19F solid-state nuclear magnetic resonance spectroscopy. This is the first example of a fabrication principle that lends itself to a wide range of promising OIPC and ionomeric materials. Subsequent studies are required to characterize and understand the morphology and conductive nature of these systems and their application as electrolyte materials.

New type of Li ion conductor with 3D interconnected nanopores via polymerization of a liquid organic electrolyte-filled lyotropic liquid-crystal assembly.

A new type of polymer electrolyte material for Li ion transport has been developed. This material is based on a polymerizable lyotropic (i.e., amphiphilic) liquid crystal (1) that forms a type-II bicontinuous cubic (Q(II)) phase with the common liquid electrolyte, propylene carbonate (PC), and its Li salt solutions. The resulting cross-linked, solid-liquid nanocomposite has an ordered, three-dimensional interconnected network of phase-separated liquid PC nanochannels and exhibits a room-temperature ion conductivity of 10(-4) to 10(-3) S cm(-1) when formed with 15 wt % 0.245 M LiClO(4)-PC solution. This value approaches that of conventional gelled poly(ethylene oxide)-based electrolytes blended with larger amounts of higher-concentration Li salt solutions. It is also similar to that of a bulk 0.245 M LiClO(4)-PC solution measured using the same AC impedance methods. Preliminary variable-temperature ion conductivity and NMR DOSY studies showed that liquidlike diffusion is present in the Q(II) nanochannels and that good ion conductivity ( approximately 10(-4) S cm(-1)) and PC mobility are retained down to -35 degrees C (and lower). This type of stable, liquidlike ion conductivity over a broad temperature range is typically not exhibited by conventional gelled-polymer- or liquid-crystal-based electrolytes, making this new material potentially valuable for enabling Li ion batteries that can operate more efficiently over a wider temperature range.