We analyze the phase behavior of polyelectrolyte salt-free solutions using the random phase approximation (RPA). Within this approximation, the phase diagrams of salt-free polyelectrolyte solutions show phase separation even without including short-range attractions or ion condensation. We find that the phase behavior of large chains resembles the phase diagram of polymer network solutions. That is, the equilibrium is established between a swollen network phase and a chain-free phase. Even though RPA is capable of reproducing certain aspects of the phase diagram, the model has to be modified to include ion condensation self-consistently in the analysis.

No abstract

No abstract

No abstract

Materials and methods:We used data from pre-existing datasets and the literature. We identified seven major noncommunicable diseases for which data were available: coronary heart disease, stroke, type 2 diabetes mellitus, breast cancer, colon cancer, chronic obstructive pulmonary disease, and asthma. We estimated the per unit cost (the annual cost of treating each illness for one person) of each disease, multiplied per unit cost by disease prevalence counts to generate disease-specific costs, and then summed across diseases. We calculated the cost of absenteeism and presenteeism by multiplying the gross domestic product per person in the labor force by the loss in productivity from each disease due to absenteeism and presenteeism, respectively, and the prevalence in the labor force of each disease. Results:We estimate that the direct medical costs of seven major noncommunicable diseases in Gulf Cooperation Council countries are $16.7 billion (2019 International $), equal to 0.6 percent of gross domestic product. We estimate that absenteeism and presenteeism due to these seven noncommunicable diseases cost 0.5 percent and 2.2 percent of gross domestic product, respectively.Limitations: Our study does not capture all noncommunicable diseases and does not capture all types of indirect costs. Our cost estimates are particularly sensitive to our assumptions regarding type 2 diabetes mellitus. Conclusion: The economic burden of noncommunicable diseases in Gulf CooperationCouncil countries is substantial, suggesting that successful preventive interventions have the potential to improve both population health and reduce costs. Further research is needed to capture a broader array of noncommunicable diseases and to develop more precise estimates.