Project description:Microfluidic magnetophoresis is a powerful technique that is used to separate and/or isolate cells of interest from complex matrices for analysis. However, mechanical pumps are required to drive flow, limiting portability and making translation to point-of-care (POC) settings difficult. Microfluidic paper-based analytical devices (μPADs) offer an alternative to traditional microfluidic devices that do not require external pumps to generate flow. However, μPADs are not typically used for particle analysis because most particles become trapped in the porous fiber network. Here we report the ability of newly developed fast-flow microfluidic paper-based analytical devices (ffPADs) to perform magnetophoresis. ffPADs use capillary action in a gap between stacked layers of paper and transparency sheets to drive flow at higher velocities than traditional μPADs. The multi-layer ffPADs allow particles and cells to move through the gap without being trapped in the paper layers. We first demonstrate that ffPADs enable magnetic particle separations in a μPAD with a neodymium permanent magnet and study key factors that affect performance. To demonstrate utility, E. coli was used as a model analyte and was isolated from human urine before detection with a fluorescently labeled antibody. A capture efficiency of 61.5% was then obtained of E. coli labeled magnetic beads in human urine. Future studies will look at the improvement of the capture efficiency and to make this assay completely off-chip without the need of a fluorescent label. The assay and device described here demonstrate the first example of magnetophoresis in a paper based, pump free microfluidic device.
Project description:Oral contraceptives (OC) are the most used form of contraception among women in the U.S. and Europe. Like other medications, their packaging must include patient information leaflets. This study quantifies the environmental impact of paper waste generated by these leaflets. We conducted an observational analysis, measuring the weight of leaflets, pills, and packaging components across various OC brands. Significant variations in leaflet weights were observed. On average, leaflets accounted for 55% of the package weight, while pills and blister dispensers represented only 32%. The mean weight of OC leaflets was 12.3 ± 5.5 grams (4.7-21.9 grams), leading to an estimated annual paper waste of 6,118.4 tons, 5,763.5 tons of carbon dioxide equivalent emissions, and the use of approximately 146,841 trees for production. Standardizing leaflet weight to the lightest reported can reduce annual waste by 3780.5 tons of paper. This study highlights the substantial environmental cost of the waste generated from OC leaflets and proposes practical strategies to mitigate waste, including electronic leaflets and standardized packaging. Targeting these materials presents a significant opportunity to enhance sustainability, aligning with global efforts to reduce greenhouse gas emissions from the healthcare sector.
Project description:This article presents processes for developing contextualized training procedures to better appreciate partnership, capacity-building experiences, and specific implementation challenges and opportunities for mental and public health teams. The program enrolled 469 out-of-school adolescents to participate in the integration of youth mental health into health and life-skill safe spaces. The teams utilized various methods to achieve process outcomes of restructuring and adapting curricula, training youth mentors, and assessing their self-efficacy before integrating the intervention for 18 months. The Coronavirus (COVID-19) pandemic became an additional unique concern in the preliminary and the 18-month implementation period of the program. This necessitated innovation around hybrid training and asynchronous modalities as program teams navigated the two study locations for prompt training, supervision, evaluation, and feedback. In conclusion, out-of-school adolescents face a myriad of challenges, and a safe space program led by youth mentors can help promote mental health. Our study demonstrated how best this can be achieved. We point to lessons such as the importance of adapting the intervention and working cohesively in teams, building strong and trusting partnerships, learning how to carry out multidisciplinary dialogues, and continuous supervision and capacity building. This article aimed to document the processes around the design and implementation of this innovative intervention and present a summary of lessons learned.
Project description:Many complex physical systems exhibit a rich variety of discrete behavioural modes. Often, the system complexity limits the applicability of standard modelling tools. Hence, understanding the underlying physics of different behaviours and distinguishing between them is challenging. Although traditional machine learning techniques could predict and classify behaviour well, typically they do not provide any meaningful insight into the underlying physics of the system. In this paper we present a novel method for extracting physically meaningful clusters of discrete behaviour from limited experimental observations. This method obtains a set of physically plausible functions that both facilitate behavioural clustering and aid in system understanding. We demonstrate the approach on the V-shaped falling paper system, a new falling paper type system that exhibits four distinct behavioural modes depending on a few morphological parameters. Using just 49 experimental observations, the method discovered a set of candidate functions that distinguish behaviours with an error of 2.04%, while also aiding insight into the physical phenomena driving each behaviour.
Project description:Detecting the concentration of free chlorine is important for monitoring the quality of water. In this study, we report a nanohybrid paper-based chemiresistive sensor that can be used with smartphones to detect free chlorine ions. The sensor was fabricated using a simple and standardized coating process. The graphene and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) nanohybrid paper-based sensing device exhibited a more stable and intuitive response to free chlorine than that exhibited by the device using only PEDOT:PSS. The nanohybrid paper-based sensor was sensitive to free chlorine concentrations in a linear range of 0.1-500 ppm, and the limit of detection was 0.18 ppm. The sensor showed specificity for free chloride ions and detection capability in samples. The sensor was integrated as a module with an electric readout system, and the measured signals and results could be displayed in real time on a smartphone. Therefore, the proposed sensing platform is suitable owing to its portability, low cost, ease of use, and capability for on-site water quality measurement.
Project description:A flexible free-standing nitrogen-doped graphene paper (N-GP) is fabricated via a facile hydrothermal approach with doping reaction occurring at the solid/gas interface of graphene oxide and ammonia vapor. Ammonia not only facilitates the doping of oxidized graphene paper efficiently with a nitrogen doping level of ca. 6.81%, but also promotes its reduction. The electrochemical properties of N-GP as an anode of lithium ion batteries (LIB) are evaluated and N-GP delivers almost doubled reversible discharge capacity compared to the undoped graphene paper (GP) as well as a good cyclic stability and rate performance. The proposed strategy to realize simultaneous reduction and nitrogen doping of graphene oxide via hydrothermal approach at the solid/gas interface offers a green and facile solution to modify graphene paper with desired electrochemical performances for LIB application.