How Notifications Affect Engagement With a Behavior Change App: Results From a Micro-Randomized Trial.

BACKGROUND: Drink Less is a behavior change app to help higher-risk drinkers in the United Kingdom reduce their alcohol consumption. The app includes a daily notification asking users to "Please complete your drinks and mood diary," yet we did not understand the causal effect of the notification on engagement nor how to improve this component of Drink Less. We developed a new bank of 30 new messages to increase users' reflective motivation to engage with Drink Less. This study aimed to determine how standard and new notifications affect engagement. OBJECTIVE: Our objective was to estimate the causal effect of the notification on near-term engagement, to explore whether this effect changed over time, and to create an evidence base to further inform the optimization of the notification policy. METHODS: We conducted a micro-randomized trial (MRT) with 2 additional parallel arms. Inclusion criteria were Drink Less users who consented to participate in the trial, self-reported a baseline Alcohol Use Disorders Identification Test score of ≥8, resided in the United Kingdom, were aged ≥18 years, and reported interest in drinking less alcohol. Our MRT randomized 350 new users to test whether receiving a notification, compared with receiving no notification, increased the probability of opening the app in the subsequent hour, over the first 30 days since downloading Drink Less. Each day at 8 PM, users were randomized with a 30% probability of receiving the standard message, a 30% probability of receiving a new message, or a 40% probability of receiving no message. We additionally explored time to disengagement, with the allocation of 60% of eligible users randomized to the MRT (n=350) and 40% of eligible users randomized in equal number to the 2 parallel arms, either receiving the no notification policy (n=98) or the standard notification policy (n=121). Ancillary analyses explored effect moderation by recent states of habituation and engagement. RESULTS: Receiving a notification, compared with not receiving a notification, increased the probability of opening the app in the next hour by 3.5-fold (95% CI 2.91-4.25). Both types of messages were similarly effective. The effect of the notification did not change significantly over time. A user being in a state of already engaged lowered the new notification effect by 0.80 (95% CI 0.55-1.16), although not significantly. Across the 3 arms, time to disengagement was not significantly different. CONCLUSIONS: We found a strong near-term effect of engagement on the notification, but no overall difference in time to disengagement between users receiving the standard fixed notification, no notification at all, or the random sequence of notifications within the MRT. The strong near-term effect of the notification presents an opportunity to target notifications to increase "in-the-moment" engagement. Further optimization is required to improve the long-term engagement. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/18690.

A toolbox of diverse arginine N-glycosylated peptides and specific antibodies.

Among posttranslational modifications, atypical arginine N-glycosylation has drawn increasing interest due to its fundamental role in various cellular procedures and signaling pathways. The efficient synthesis of arginine N-glycosylated substrates, as well as the generation of specific antibodies, remains challenging. This work describes the efficient synthesis of diverse arginine N-glycosylated peptides, in a process termed silver-promoted solid-phase glycosylation (SGG). There are two key features of the SSG strategy: (i) robust synthesis of gram-scale S-alkyl-isothiourea glycosyl donors facilitates the subsequent SSG procedure and (ii) the simultaneous introduction of both the side-chain sugar motif and arginine residue. Notably, our findings, combined with our previous results, provide a toolbox containing diverse S-alkyl-isothiourea glycosyl donors (glucose, galactose, mannose, ribose, xylose, lactose and maltose) as well as the corresponding Arg N-glycosylated peptides. In addition, our toolbox is shown to help investigate specific antibodies and identify multiple potent and precise biochemical tools for exploring arginine N-glycosylation.

Integrated Metabolomics and Network Pharmacology Revealed Hong-Hua-Xiao-Yao Tablet's Effect of Mediating Hormone Synthesis in the Treatment of Mammary Gland Hyperplasia.

Hong-Hua-Xiao-Yao Tablet (HHXYT) is a traditional Chinese medicine (TCM) formula that has been approved for the treatment of mammary gland hyperplasia (MGH), but its mechanism of action is unclear. In this study, a strategy that integrated metabolomics and network pharmacology was applied to systemically reveal the mechanism of HHXYT in the treatment of MGH. Our pharmacodynamic study indicated that the proliferation of mammary gland was inhibited in rats, and serum-level disorder of estradiol and progesterone was reversed after HHXYT treatment. 54 compounds absorbed in rat plasma were identified after administration of HHXYT. The serum metabolome revealed 58 endogenous differential metabolites, of which 31% were steroid lipids metabolites, with steroid hormone biosynthesis being the most significant metabolic module. 7 targets, 6 herbs, and 17 ingredients were found to play key roles in HHXYT's treatment of MGH. 3 of the 7 key targets (CYP11A1, HSD3B2, and CYP17A1) were directly involved in androgen synthesis, while 2 targets (AR and ESR1) were receptors for the direct action of androgens and estrogens. Molecular docking was utilized to confirm the bindings between the 5 targets and their corresponding compounds. In an in vitro test, HHXYT (50 µg/ml) and its ingredient formononetin (3.2, 6.3, and 12.5 µM) were found to significantly reduce the increase of testosterone level induced by dexamethasone (10 µM) in thecal cells. In summary, this study illustrated that the mechanism of HHXYT's treatment of MGH was to regulate hormone disorder. HHXYT could reduce estrogen-stimulated hyperplasia by inhibiting the production of its precursor androgen.

Rational design of stapled peptides targeting phosphorylated GSK3ß for regulating osteoclast differentiation.

Glycogen synthase kinase-3ß (GSK-3ß), has been reported to show essential roles in osteoclast differentiation. Modeled after FRATtide, a peptide derived from a GSK-3 binding protein, here we designed and synthesized a series of stapled peptides targeting phosphorylated GSK3ß, and evaluated the corresponding biological activities. The results indicated that stapled peptides with better helical contents and proteolytic stability than the linear ones showed improved biological activity in inhibiting osteoclast differentiation. Among them, FRC-2 and FRN-2 showed promising prospects for treating osteoporosis.

Greatly enhanced energy density and patterned films induced by photo cross-linking of poly(vinylidene fluoride-chlorotrifluoroethylene).

Greatly enhanced energy density in poly(vinylidene fluoride-chlorotrifluoroethylene) [P(VDF-CTFE)] is realized through interface effects induced by a photo cross-linking method. Being different from nanocomposites with lowered dielectric strength, the cross-linked P(VDF-CTFE)s possess a high breakdown field as well as remarkably elevated polarization, both of which contribute to the enhanced energy density as high as 22.5 J · cm(-3). Moreover, patterned thin films with various shapes and sizes are fabricated by photolithography, which sheds new light on the integration of PVDF-based electroactive polymers into organic microelectronic devices such as flexible pyroelectric/piezoelectric sensor arrays or non-volatile ferroelectric memory devices.