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1.
Internet Interv ; 35: 100697, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38149089

RESUMEN

Low adherence in self-guided internet interventions is linked to poorer outcomes. Although some predictors of adherence have been identified, few are modifiable for widespread application. One personal variable with the potential to increase adherence in internet interventions is context-specific self-efficacy. This protocol outlines a randomized controlled trial design, divided into two phases. In Phase 1 (students, N = 216), participants will complete a self-efficacy-enhancing exercise, which will be compared to a waitlist control group to test its effectiveness in increasing internet intervention adherence self-efficacy. Phase 2 will be the main two-arm trial, where all participants (medical students, N = 952) will undergo an internet intervention called Med-Stress Student. In the experimental group, the program will be preceded by the self-efficacy-enhancing exercise developed in Phase 1. We anticipate that participants in the experimental group will show higher adherence (primary outcome) to the intervention and greater improvement in intervention outcomes (secondary outcomes i.e., lower stress and higher work engagement) at posttest, as well as at six-month and one-year follow-ups. If effective, enhancing context-specific self-efficacy could be recommended before any internet intervention as a relatively simple way to boost participants' adherence.

3.
Internet Interv ; 33: 100653, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37575678

RESUMEN

In order to be more accessible and overcome the challenges of low adherence and high dropout, self-guided internet interventions need to seek new delivery formats. In this study, we tested whether a widely-adopted social media app - Meta's (Facebook) Messenger - would be a suitable conveyor of such an internet intervention. Specifically, we verified the efficacy of Stressbot: a Messenger chatbot-delivered intervention focused on enhancing coping self-efficacy to reduce stress and improve quality of life in university students. Participants (N = 372) were randomly assigned to two conditions: (1) an experimental group with access to the Stressbot intervention, and (2) a waitlist control group. Three outcomes, namely coping self-efficacy, stress, and quality of life, were assessed at three time points: a baseline, post-test, and one-month follow-up. Linear Mixed Effects Models were used to analyze the data. At post-test, we found improvements in the Stressbot condition compared to the control condition for stress (d = -0.33) and coping self-efficacy (d = 0.50), but not for quality of life. A sensitivity analysis revealed that the positive short-term intervention effects were robust. At the follow-up, there were no differences between groups, indicating that the intervention was effective only in the short term. In sum, the results suggest that the Messenger app is a viable means to deliver a self-guided internet intervention. However, modifications such as a more engaging design or boosters are required for the effects to persist.

4.
ACS Omega ; 8(44): 41991-42003, 2023 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-37969970

RESUMEN

The construction of artificial systems for solar energy harvesting is still a challenge. There needs to be a light-harvesting antenna with a broad absorption spectrum and then the possibility to transfer harvested energy to the reaction center, converting photons into a storable form of energy. Bioinspired and bioderivative elements may help in achieving this aim. Here, we present an option for light harvesting: a nanobiohybrid of colloidal, semiconductor quantum dots (QDs) and natural photosynthetic antennae assembled on the surface of a carbon nanotube. For that, we used QDs of cadmium telluride and cyanobacterial phycobilisome rods (PBSr) or light-harvesting complex II (LHCII) of higher plants. For this nanobiohybrid, we confirmed composition and organization using infrared spectroscopy, X-ray photoelectron spectroscopy, and high-resolution confocal microscopy. Then, we proved that within such an assembly, there is a resonance energy transfer from QD to PBSr or LHCII. When such a nanobiohybrid was further combined with thylakoids, the energy was transferred to photosynthetic reaction centers and efficiently powered the photosystem I reaction center. The presented construct is proof of a general concept, combining interacting elements on a platform of a nanotube, allowing further variation within assembled elements.

5.
Chem Sci ; 8(1): 361-365, 2017 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-28451180

RESUMEN

Here we present a molecular architecture that can reversibly change the geometric conformation of its π-system backbone via irradiation with two different wavelengths. The proposed 'molecular actuator' consists of a photoswitchable azobenzene orthogonally connected to a π-conjugated bithiophene by both direct and aliphatic linker-assisted bonding. Upon exposure to 350 nm light, the trans azobenzene moiety isomerizes to its cis form, causing the bithiophene to assume a semiplanar anti conformation (extended π-conjugation). Exposure to 254 nm light promotes the isomerization of the azobenzene unit back to its initial extended trans conformation, thus forcing the bithiophene fragment to twist out of coplanarity (restricted π-conjugation). The molecular conformation of the bithiophene was characterized using steady-state UV-vis and nuclear magnetic resonance spectroscopy, as well as ab initio computations. The proposed molecular design could be envisaged as a π-conjugation modulator, which has potential to be incorporated into extended linear π-systems, i.e. via the terminal α-thiophene positions, and used to tune their optical and electronic properties.

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