Leveraging Diffusion Kinetics to Reverse Propane/Propylene Adsorption in Zeolitic Imidazolate Framework-8.

The separation challenge posed by propylene/propane mixtures arises from their nearly identical molecular sizes and physicochemical properties. Metal-organic frameworks (MOFs) have demonstrated potential in addressing this challenge through the precision tailoring of pore sizes and surface chemistry. However, introducing modifications at the molecular level remains a considerable hurdle. This work presents an approach to reversibly tune the propylene/propane adsorption preference in zeolitic imidazolate framework-8 (ZIF-8) by manipulating the particle size and gas flow rate. Systematically increasing the ZIF-8 crystals from 9 to 224 µm restricts propane diffusion, thereby reversing its preferential adsorption over propylene. Furthermore, raising the gas flow rate of mixed propylene/propane shifts the rate-determining breakthrough step from thermodynamic equilibrium to kinetics, again reversing the adsorption preference in a particular ZIF-8 sample. We propose "dynamic selectivity (Sd(t))" as a concept that incorporates both thermodynamic and kinetic factors to elucidate these unexpected findings. Moreover, the driving force equation, grounded on the concept of Sd(t), has improved the precision and stability of the computational simulation for fixed-bed adsorption processes. This work underscores the potential of diffusion-based modulation, implemented through manageable external changes, as a viable strategy to optimize separation performance in porous adsorbent materials.

Social network research hotspots and trends in public health: A bibliometric and visual analysis.

Objectives: To understand the research landscape and identify the research hotspots and trends of the application of social network theory and analysis to public health. Study design: A bibliometric study of publications regarding application of social network theory and analysis to public health. Methods: Choosing 1607 articles about the application of social network theory and analysis to public health from the core collection database of Web of Science published from 1991 to 2020 as the research sample. A bibliometric and visual analysis of publication quantity and content was performed to analyze time trends, spatial distribution, cooperation networks, influential references, and keyword co-occurrence, clusters, and emergence. Results: There is an increasing trend in the use of social network theory and analysis in the public health field, with the United States taking the lead. Research focuses include on transmission of diseases or behavior through social networks and the influence of social networks on population health at different ages. Current research frontiers primarily include the role of social networks in tracking of emerging infectious diseases like COVID-19, preventing and controlling chronic diseases, and carrying out healthy behavioral interventions. Conclusions: This study provides a comprehensive quantitative overview of the historic development of and latest topics in the application of social network theory and analysis method to public health. More attention should be paid to the important role of social networks in tracing the emergence of serious infectious diseases like COVID-19, as well as preventing and controlling chronic diseases and intervening in health behaviors, considering the increasing challenges and opportunities presented by online social networking.

Barriers and Strategies: A Review of Access to Affordable Multi-Drug Resistant Tuberculosis Medication in China.

This study analyzed the barriers of patient access to affordable MDR-TB medication in China and the reasons behind, and proposed strategies towards removing the barriers based on literature review and key informant interviews. Reasons behind the high financial burden of MDR-TB patients in China are the lack of a coordinated and multi-sourced financing model to secure patients' access to the expensive novel medicines, and the absence of the safety-net for the patients with low ability to pay the costs. Appropriate health insurance benefit packages and provider payment mechanisms, supportive legal framework, coordinated policies as well as incentives for off-label use of evidence-based repurposed medicines are missing. The observations identified key intervention areas including continued efforts to make the novel effective medicines affordable and to strengthen the legislative protection for off-label use of evidence-based medicines; increase incentives for pharmaceutical companies to expand indications of established medicines based on the evidence; implement public initiatives to support the use of repurposed medicines for diseases with major public health significance, and scale up good practices from local pilots to create a coordinated multi-sourced financing model. A comprehensive approach to address the barriers in the full treatment course of MDR-TB and a safety-net for low-ability-to-pay patients are also critical to secure universal access to affordable MDR-TB medication.