ABSTRACT
BACKGROUND: This study aimed to assess the acceptability, feasibility, and preliminary effectiveness of a crowdsourced HIV partner services (PS) intervention among men who have sex with men living with HIV (MLWH) in China. METHODS: A pilot two-arm randomized controlled trial (RCT) was conducted in three HIV testing clinics in China. The control arm received conventional HIV PS while the intervention arm received a crowdsourced intervention, including HIV self-testing kits for secondary distribution (HIVST-SD), digital education materials, and assisted PS. The intervention was developed through two-phase crowdsourcing events including an open call and a Designathon. The primary outcomes were measured by the 3-month follow-up rate (i.e., the proportion of participants who completed the follow-up survey to report HIV PS outcomes three months after enrollment) and the frequency of using intervention components (feasibility), index evaluation of intervention components (acceptability), and the proportion of partners getting HIV testing (preliminary effectiveness). RESULTS: The study enrolled 121 newly diagnosed MLWH between July 2021 and May 2022. The 3-month follow-up rates were 93% (75/81) and 83% (33/40) in the intervention and control arms, respectively. Crowdsourced intervention components demonstrated feasibility, with all indexes utilizing digital educational materials, 23 successfully using HIVST-SD, and six employing provider-referral to notify nine sexual partners. Acceptability was high, with HIVST-SD and digital educational materials rated 4·4 and 4.1 out of 5. The proportion of partners receiving HIV testing was 11% higher in the intervention arm than in the control arm (marginal significance with 95% CI = [-2%, 24%], 38% vs. 27%). CONCLUSION: The crowdsourced HIV PS intervention was acceptable and feasible, suggesting the potential to facilitate partner HIV testing among Chinese MLWH. Further implementation research is recommended to expand HIV PS among key populations in low- and middle-income countries.Clinical trial registration ID: NCT04971967 (Protocol ID: 19-0496).
ABSTRACT
The CO2 aqueous foams stabilized by bioresource-derived ultra-long chain surfactants have demonstrated considerable promising application potential owing to their remarkable longevity. Nevertheless, existing research is still inadequate to establish the relationships among surfactant architecture, environmental factors, and foam properties. Herein, two cases of ultra-long chain tertiary amines with different tail lengths, N-erucamidopropyl-N,N-dimethylamine (UC22AMPM) and N-oleicamidopropyl-N,N-dimethylamine (UC18AMPM), were employed to fabricate CO2 foams. The effect of temperature, pressure and salinity on the properties of two foam systems (i.e., foamability and foam stability) was compared using a high-temperature, high-pressure visualization foam meter. The continuous phase viscosity and liquid content for both samples were characterized using rheometry and FoamScan. The results showed that the increased concentrations or pressure enhanced the properties of both foam samples, but the increased scope for UC22AMPM was more pronounced. By contrast, the foam stability for both cases was impaired with increasing salinity or temperature, but the UC18AMPM sample is more sensitive to temperature and salinity, indicating the salt and temperature resistance of UC18AMPM-CO2 foams is weaker than those of the UC22AMPM counterpart. These differences are associated with the longer hydrophobic chain of UC22AMPM, which imparts a higher viscosity and lower surface tension to foams, resisting the adverse effects of temperature and salinity.
ABSTRACT
Smart foams sensitive to external stimulation have gained increasing attention recently. However, reversibly switchable CO2 foams have been less documented. In this work, a novel kind of CO2-switchable foams was developed using a long-chain cationic surfactant, N-erucamidopropyl-N,N-dimethylammonium bicarbonate (UC22AMPMâ H+), as both the foaming agent and stabilizer. The foams can be rapidly transformed between stable and unstable states at ambient temperature with CO2/NH3·H2O as the triggers. The foaming properties and switchable performance were examined by a combination of confocal microscopy, cryogenic transmission electron microscopy, and rheological techniques. The results demonstrated that the enhanced foam stability in the presence of CO2 is attributed to the high bulk phase viscosity and gas/liquid surface viscosity, resulting from the entanglement of wormlike micelles (WLMs) formed from UC22AMPMâ H+. When NH3·H2O is added, the network structure of WLMs is disrupted, and the bulk phase viscosity and surface viscosity subsequently drop, consequently leading to an ultimate foam destabilization. Such a CO2-sensitive viscoelastic surfactant could not only be used to fabricate smart CO2 foams but can also enable CO2 to play dual roles as both the dispersed phase, as most gases do, and an "activator" to protonate long-chain tertiary surfactants into cationic analogs to form viscoelastic WLMs to stabilize foams.
