Search

Abstract Controlling drug release rate and providing physical and chemical stability to the active pharmaceutical ingredient are key properties of oral solid dosage forms. Here, we demonstrate a formulation strategy using phase-separated polymer blends where the morphology provides a route for tuning the drug release profile. By utilising phase separation of a hydrophobic and a hydrophilic polymer, the hydrophilic component will act as a channelling agent, creating a porous network upon dissolution that will dictate the release characteristics. With ptychographic X-ray tomography and scanning transmission X-ray microscopy we reveal how the morphology depends on both polymer fraction and presence of drug, and how the drug is distributed over the polymer domains. Combining X-ray imaging results with dissolution studies reveal how the morphologies are correlated with the drug release and showcase how tuning the morphology of a polymer matrix in oral formulations can be utilised as a method for controlled drug release.

Understanding the plating and stripping behaviours of lithium metal is crucial for high-energy battery development. Here, authors track these electrochemical processes in real time by an operando synchrotron X-ray tomographic microscopy, revealing the formation of inactive lithium microstructures.

Abstract Rechargeable zinc metal batteries are greener and safer alternative to lithium batteries, but they suffer from poor reversibility due to growth of zinc dendrites and water splitting reactions of aqueous electrolytes. One strategy to overcome these drawbacks is replacing aqueous electrolyte with solid polymer electrolyte (SPE). In this work, we examine the possibility of fabricating solid electrolyte from a bio‐based polymer, hydroxyethylcellulose (HEC), with the aim to further increase the sustainability of zinc batteries. Various types of zinc salts, drying procedures and the salt concentrations are investigated for their impact on the ionic conductivity, structure, and phase behavior of as‐prepared polymer electrolytes. It is found that HEC has a good film‐forming ability compared with commonly used poly(ethylene oxide) but its low salt‐dissociation capability leads to an ionic conductivity of 10−6 S cm−1 even at the elevated temperature of 110°C, hindering the possibility of solely utilizing HEC as matrix of solid electrolyte. Our results suggest that introducing a new polymer with higher salt‐dissociation capability or lower glass transition temperature into the HEC matrix can be a reliable way to build solid polymer electrolytes with sufficient ionic conductivity and good mechanical property for future zinc batteries.

Highly concentrated electrolytes have been found to improve the cycle life and Coulombic efficiency of lithium metal anodes, as well as to suppress dendrite growth. However, the mechanism for these improvements is not well understood. Partly, this can be linked to the difficulty of accurately characterizing the solid electrolyte interphase (SEI), known to play an important role for anode stability and stripping/plating efficiency. Herein, in situ neutron reflectometry is used to obtain information about SEI formation in a highly concentrated ether‐based electrolyte. With neutron reflectometry, the thickness, scattering length density (SLD), and roughness of the SEI layer formed on a Cu working electrode are nondestructively probed. The reflectivity data point to the formation of a thin (5 nm) SEI in the highly concentrated electrolyte (salt:solvent ratio 1:2.2), while a considerably thicker (13 nm) SEI is formed in an electrolyte at lower salt concentration (salt:solvent ratio 1:13.7). Further, the SEI formed in the electrolyte with high salt concentration has a higher SLD, suggesting that the chemical composition of the SEI changes. The results from neutron reflectometry correlate well with the electrochemical data from SEI formation.

Smartphone psychotherapies are growing in popularity, yet little is understood about (1) how people prefer to engage with psychotherapy apps, or (2) which engagement patterns constitute effective engagement. The present study uses secondary data from a 12-week randomized waitlist-controlled trial of smartphone-delivered cognitive behavioral therapy (CBT) for body dysmorphic disorder (BDD) (N = 77) to address these aims. Additionally, using the present study as a use-case, we seek to provide a roadmap for how researchers may improve upon methodological limitations of existing smartphone psychotherapy engagement research. We measured behavioral engagement via 19 objective variables derived from phone analytics data, which we reduced via factor analysis into two factors: 1) use volume and frequency, and 2) session duration. Cluster analysis based on engagement factors yielded three engager types, which mapped onto “deep” users, “samplers,” and “light” users. The clusters did not differ significantly in improvement in BDD severity across treatment, although deep users improved more than light users at a marginally significant level. Results suggest that varying patterns of preferred engagement may be efficacious. Moreover, the study's methods provide an example of how researchers can measure and study behavioral engagement comprehensively and objectively.Trial Registration: ClinicalTrials.gov Identifier: NCT04034693

Abstract It is widely assumed that the longer we spend in happier activities the happier we will be. In an intensive study of momentary happiness, we show that, in fact, longer time spent in happier activities does not lead to higher levels of reported happiness overall. This finding is replicated with different samples (student and diverse, multi-national panel), measures and methods of analysis. We explore different explanations for this seemingly paradoxical finding, providing fresh insight into the factors that do and do not affect the relationship between how happy we report feeling as a function of how long it lasts. This work calls into question the assumption that spending more time doing what we like will show up in making us happier, presenting a fundamental challenge to the validity of current tools used to measure happiness.

A plethora of past studies have highlighted a negative association between phone use and well-being. Recent studies claimed that there is a lack of strong evidence on the deleterious effects of smartphones on our health, and that previous systematic reviews overestimated the negative link between phone use and well-being. In a three-week long in-the-wild study with 352 participants, we captured 15,607 instances of smartphone use in tandem with rich contextual information (activity, location, company) as well as self-reported well-being measures. We conducted an additional study to gather users’ perception of the impact of phone use on their well-being in different daily contexts. Our findings show that context and personal characteristics greatly impact the association between screen time and subjective well-being. This study highlights the complexity of the relationship between phone use and well-being and it deepens our understanding of this problem.

Digital mental health applications promise scalable and cost-effective solutions to mitigate the gap between the demand and supply of mental healthcare services. However, very little attention is paid on differential impact and potential discrimination in digital mental health services with respect to different sensitive user groups (e.g., race, age, gender, ethnicity, socio-economic status) as the extant literature as well as the market lack the corresponding evidence. In this paper, we outline a 7-step model to assess algorithmic discrimination in digital mental health services, focusing on algorithmic bias assessment and differential impact. We conduct a pilot analysis with 610 users of the model applied on a digital wellbeing service called Foundations that incorporates a rich set of 150 proposed activities designed to increase wellbeing and reduce stress. We further apply the 7-step model on the evaluation of two algorithms that could extend the current service: monitoring step-up model, and a popularity-based activities recommender system. This study applies an algorithmic fairness analysis framework for digital mental health and explores differences in the outcome metrics for the interventions, monitoring model, and recommender engine for the users of different age, gender, type of work, country of residence, employment status and monthly income.Systematic Review Registration: The study with main hypotheses is registered at: https://osf.io/hvtf8

Nanocomposite systems comprised of a poly(ethylene vinyl acetate) (EVA) matrix and carbon black (CB) or graphene nanoplatelets (GNPs) were used to investigate conductivity and crystallisation dynamics using a commercially relevant melt-state mixing process. Crystallisation kinetics and morphology, as investigated by DSC and SEM, turn out to depend on the interplay of (i) the interphase interactions between matrix and filler, and (ii) the degree of filler agglomeration. For the GNP-based systems, an almost constant conductivity value was observed for all compositions upon cooling, something not observed for the CB-based compositions. These conductivity changes reflect structural and morphological changes that can be associated with positive and negative thermal expansion coefficients. GNP-based systems were observed to exhibit a percolation threshold of approximately 2.2 vol%, lower than the 4.4 vol% observed for the CB-based systems.

Abstract Due to an ultrahigh theoretical specific capacity of 3860 mAh g−1, lithium (Li) is regarded as the ultimate anode for high‐energy‐density batteries. However, the practical application of Li metal anode is hindered by safety concerns and low Coulombic efficiency both of which are resulted fromunavoidable dendrite growth during electrodeposition. This study focuses on a critical parameter for electrodeposition, the exchange current density, which has attracted only little attention in research on Li metal batteries. A phase‐field model is presented to show the effect of exchange current density on electrodeposition behavior of Li. The results show that a uniform distribution of cathodic current density, hence uniform electrodeposition, on electrode is obtained with lower exchange current density. Furthermore, it is demonstrated that lower exchange current density contributes to form a larger critical radius of nucleation in the initial electrocrystallization that results in a dense deposition of Li, which is a foundation for improved Coulombic efficiency and dendrite‐free morphology. The findings not only pave the way to practical rechargeable Li metal batteries but can also be translated to the design of stable metal anodes, e.g., for sodium (Na), magnesium (Mg), and zinc (Zn) batteries.

Abstract We report on a new strategy to improve the capacity, reduce the manufacturing costs and increase the sustainability of Lithium-Sulfur (LiS) batteries. It is based on a semi-liquid cathode composed of a Li2S8 polysulphide catholyte and a binder-free carbon nanofiber membrane with tailored morphology. The polysulphides in the catholyte have the dual role of active material and providing Li+-conduction, i.e. no traditional Li-salt is used in this cell. The cell is able to deliver an areal capacity as high as 7 mAh cm−2, twice than that of commercial Lithium-ion batteries (LiBs) and 2–4 times higher than that of state-of-the-art LiS cells. In addition, the battery concept has an improved sustainability from a material point of view by being mainly based on sulfur and carbon and being completely fluorine-free, no fluorinated salt or binders are used, and has potential for upscaling and competitive price. The combination of these properties makes the semi-liquid LiS cell here reported a very promising new concept for practical large-scale energy storage applications.

The use of chalcogenide elements, such as sulfur (S) and selenium (Se), as cathode materials in rechargeable lithium (Li) and sodium (Na) batteries has been extensively investigated. Similar to Li and Na systems, rechargeable potassium–sulfur (K–S) and potassium–selenium (K–Se) batteries have recently attracted substantial interest because of the abundance of K and low associated costs. However, K–S and K–Se battery technologies are in their infancy because K possesses overactive chemical properties compared to Li and Na and the electrochemical mechanisms of such batteries are not fully understood. This paper summarizes current research trends and challenges with regard to K–S and K–Se batteries and reviews the associated fundamental science, key technological developments, and scientific challenges to evaluate the potential use of these batteries and finally determine effective pathways for their practical development.