Background Well-designed mobile health (mHealth) interventions support a positive user experience; however, a high rate of disengagement has been reported as a common concern regarding mHealth interventions. To address this issue, it is necessary to summarize the design features that improve user engagement based on research over the past 10 years, during which time the popularity of mHealth interventions has rapidly increased due to the use of smartphones. Objective The aim of this review was to answer the question “Which design features improve user engagement with mHealth interventions?” by summarizing published literature with the purpose of guiding the design of future mHealth interventions. Methods This review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) checklist. Databases, namely, PubMed, Web of Science, Cochrane Library, Ovid EMBASE, and Ovid PsycINFO, were searched for English and Chinese language papers published from January 2009 to June 2019. Thematic analysis was undertaken to assess the design features in eligible studies. The Mixed Methods Appraisal Tool was used to assess study quality. Results A total of 35 articles were included. The investigated mHealth interventions were mainly used in unhealthy lifestyle (n=17) and chronic disease (n=10) prevention programs. Mobile phone apps (n=24) were the most common delivery method. Qualitative (n=22) and mixed methods (n=9) designs were widely represented. We identified the following 7 themes that influenced user engagement: personalization (n=29), reinforcement (n=23), communication (n=20), navigation (n=17), credibility (n=16), message presentation (n=16), and interface aesthetics (n=7). A checklist was developed that contained these 7 design features and 29 corresponding specific implementations derived from the studies. Conclusions This systematic review and thematic synthesis identified useful design features that make an mHealth intervention more user friendly. We generated a checklist with evidence-based items to enable developers to use our findings easily. Future evaluations should use more robust quantitative approaches to elucidate the relationships between design features and user engagement.

Protein-based adhesives have gained considerable interest, due to their unique ecofriendliness and abundant functional groups. However, the presence of polar groups results in poor water resistance and unsatisfactory bonding strength of protein-based adhesives, limiting their practical applications. In addition, the complicated preparation process also made the production of protein-based adhesives time-consuming and costly. In this work, a hydrophobic protein zein, which lacks polar groups, was chosen as a basic ingredient for the preparation of protein-based adhesive. Sodium dodecyl sulfate (SDS) with a concentration of 200 mmol/L was added to promote the dissolution of zein and also render it negatively charged. The cations in metal chloride solution effectively cross-linked with SDS modified zein molecular chains, resulting in the formation of final zein-based adhesives. Results showed that a zein-based adhesive formed after treatment with 5 wt % FeCl3 aqueous solution (Fe­(III)@zein/SDS adhesive) showed the best performance. It indicates that Fe­(III)@zein/SDS adhesive could bond a wide range of materials. Four common substrates were chosen to test the adhesive properties of Fe­(III)@zein/SDS adhesive at 25 °C, including one inorganic material glass, one metal material copper, and two organic polymer materials polyvinyl chloride (PVC) and polyimide (PI). The adhesive strength of Fe­(III)@zein/SDS adhesive was found from 125 kPa (PI) to 586 kPa (copper) in dry conditions, while from 12 kPa (copper) to 33 kPa (PI) in the wet state, displaying a promising adhesive strength in both dry and wet conditions. Meanwhile, the Fe­(III)@zein/SDS adhesive can be easily removed from the attached surfaces without nonchemical contamination by immersing in 70% ethanol aqueous solution. Therefore, such an environmentally friendly protein-based adhesive has great potential for practical use in various fields.

In this study, zein, a renewable natural biopolymer from corn, was used to prepare a new biodegradable material with poly(butylene adipate-terephthalate) (PBAT) by reactive blending in the presence of poly(ethylene glycol diglycidyl ether) (PEGDGE). The effects of blending temperature and zein content on the morphology and mechanical and thermal properties of PBAT/zein blends with or without PEGDGE were investigated. Because of the high reactivity of the epoxy group in PEGDGE, the interfacial compatibility between zein and PBAT was improved greatly, and zein exhibited as a spheral phase with smaller size and finer dispersion in the PBAT matrix after the introduction of PEGDGE. Therefore, PEGDGE served as a plasticizer and reactive compatibilizer in the PBAT/zein blending system. Both the tensile strength and elongation at break of the blends with PEGDGE were improved greatly compared with those of the blends without PEGDGE but decreased gradually with the increase of zein content. These findings may provide a feasible way to utilize zein widely, and the new biodegradable blends with excellent stretchability could be used as packing materials in the future.

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Background and Objective: Propofol is the most commonly used sedative in gastrointestinal endoscopic procedures, but is associated with cardiorespiratory suppression, particularly in elderly patients. Remimazolam is a new short-acting GABA(A) receptor agonist with minimal impact on cardiorespiratory suppression, and may be a viable alternative in elderly patients undergoing endoscopic procedures.Methods: This multicenter, randomized controlled trial was conducted between September 2020 and September 2021. Elderly patients (65-85 years of age) scheduled to undergo upper gastrointestinal endoscopy were randomized in 1:1 ratio to receive remimazolam tosilate (300 mg/h) or propofol (3 g/h) in addition to 50-μg fentanyl, until the Modified Observer's Assessment of Alertness/Sedation Scale (MOAA/S) reached ≤1. MOAA/S was maintained at 0 or 1 throughout the procedure using 2.5 mg remimazolam or 0.5 mg/kg propofol boluses in the two groups, respectively. The primary outcome was the rate of hypotension (defined as systolic blood pressure at ≤90 mmHg or > 30% decline vs. the baseline). Bradycardia was defined as heart rate ≤50 per minute; respiratory depression was defined as respiratory rate <8 per minute and/or SpO 2 < 90%.Results: A total of 400 patients (161 men and 239 women; 70.4 ± 4.6 years of age) were enrolled (200 patients per group). Average body mass index was 22.2 ± 2.4 kg/m 2 . The rate of hypotension was 36.5% in the remimazolam group and 69.6% in the propofol group (p < 0.001). The remimazolam group also had a lower Kejian Lu, Shanshan Wei and Wenwen Ling contributed equally to this work.