Effects of government subsidies on production and emissions reduction decisions under carbon tax regulation and consumer low‐carbon awareness

To promote low-carbon production, the government simultaneously provides some subsidies under carbon tax regulations. Two government subsidies are widely adopted: one is based on emissions reduction quantity and the other is based on emissions reduction investment cost. Additionally, consumer low-carbon awareness has also been enhanced. Considering the aforementioned circumstances, this paper investigates the effects of different government subsidies on production and emissions reduction decisions under a carbon tax regulation by formulating three decision-making optimization models. The results show that (1) although the carbon tax regulation cannot guarantee further improvement of emissions reduction levels, government subsidies could make the corresponding conditions of improving emissions reduction investments wider; (2) a heavy carbon tax or stronger consumer low-carbon awareness would make the positive effect of government subsidies more apparent; and (3) subsidy policies may also be selected by the government from different perspectives, such as manufacturer development, consumer surplus, environmental damage and social welfare. Especially, from the perspective of maximizing social welfare, investment cost (IC) subsidy is not always advantageous, while emissions reduction (ER) subsidy can always bring higher social welfare compared with the case under no government subsidy

Changes in inequality in utilization of preventive care services: evidence on China’s 2009 and 2015 health system reform

BACKGROUND: Ensuring equal access to preventive care has always been given a priority in health system throughout world. This study aimed to decompose inequality in utilization of preventive care services into its contributing factors and then explore its changes over the period of China's 2009-2015 health system reform. METHODS: The concentration index (CI) and decomposition of the CI was performed to capture income-related inequalities in preventive services utilization and identify contribution of various determinants to such inequality using data from China Health and Nutrition Survey. Then, changes in inequality from 2009 to 2015 were estimated using Oaxaca-type decomposition technique. RESULTS: The CI for preventive services utilization dropped from 0.2240 in 2009 to 0.1825 in 2015. Residential location and household income made the biggest contributions to income-related inequalities in these two years. Oaxaca decomposition revealed changes in residential location, regions and medical insurance made positive contributions to decline in inequality. However, alternation in household income, age and medical services utilization pushed the equality toward deterioration. CONCLUSION: The pro-rich inequality in preventive healthcare services usage is evident in China despite a certain decline in such inequality during observation period. Policy actions on eliminating urban-rural and income disparity should be given the priority to equalize preventive healthcare

Cellular responses to culture substrates with programmable anisotropy

Physiologically relevant culture substrates are needed to accurately model cell and tissue function in vitro to characterize function in both healthy and altered (diseased) states. In addition to their use as model systems, exerting control over cellular function in a biochemical engineering process through cell-substrate interactions may reveal new ways to increase yield or efficiency. While knowledge of cellular responses to elastic substrates has advanced greatly, it was only recently recognized that cellular interactions with viscous components of networks alters mammalian cell spreading, migration, proliferation, and differentiation. Matrix studies have shown varying results in response to stress relaxation timescales however, indicating that multiple factors contribute to the cell\u27s interpretation of its mechanical microenvironment. We hypothesize that there is an additional, critical design parameter that has not been considered: the length scales over which cells sense mechanical properties. This work seeks to investigate these questions using a new type of culture substrate based on cytocompatible liquid crystalline (LC) polymers. This work focuses on the design, synthesis, and characterization of new biomaterial substrates whose viscoelastic properties can be manipulated by controlling the liquid crystalline (LC) ordering within the material. These materials also have the ability to morph in shape in response to an external stimulus (e.g. light), which may be applied during in vitro culture to result in dynamic culture substrates. A unique feature is that order can be programmed from the molecular scale to the macroscale, which permits study of how cells interact with the substrates across different length scales. To enable these studies, liquid crystallinity must be maintained in a hydrated network, which is inherently challenging because swelling of polymers tends to increase the distance between LC molecules to weaken their ordering. This work prepares new LC networks using Click chemistry, which was selected for its efficiency under mild reaction conditions that can be used to incorporate more sensitive biological molecules. This work seeks to combine the dynamic properties of these LC materials with their low cytotoxicity, stability in a hydrated phase, and ability to be processed into scaffolds and gels for use as hydrated and responsive culture substrates. The goals are to first characterize the impact of composition on liquid crystalline ordering and culture substrate properties before quantifying the impacts of substrate anisotropy and mechanics, programmed at different length scales, on mesenchymal stem cell differentiation. To prepare the materials, alkyne-terminated liquid crystalline monomers (mesogens) and azide-terminated polyether chain extenders (PEO poly(ethylene oxide); PPO poly(propylene oxide)) were synthesized and purified by modifying established reactions. Chain extender molecular weight and composition were varied to afford control over water uptake and LC organization. For one-step LC network synthesis, chemically crosslinked networks were synthesized by polymerizing the mesogens and chain extenders with a tetraazide crosslinker. To enable cell encapsulation, a two-step network synthesis was used, where azide-terminated LC prepolymers were crosslinked in water using multifunctional strained alkyne. Scaffolds were also prepared to enable 3D studies by polymerizing the reactive mixture in the presence of sodium chloride (sieved to 500-600 μm) and extracting the salt once the reaction was complete. All LC networks were found to organize into the smectic phase. By varying the composition and molecular weight of the chain extender, the material’s elastic modulus and stability of the LC phase was tailored. The networks were found to display reversible shape changing, where the films extended in the LC phase and contracted in the isotropic phase. Composition was found to impact the ability of the network to change shape and the amount of strain generated. Additionally, stress relaxation experiments conducted in the hydrated state showed that networks that were isotropic were found to respond elastically, but LC networks displayed more viscous responses. Mesenchymal stem cells incubated with extractable materials displayed no differences in cellular toxicity compared to tissue culture controls. Cells were found to attach and proliferate on the hydrated LC networks, but attachment was found to be about 50% that of the tissue culture plastic. Adsorption of gelatin with fibronectin onto the networks successfully increased cell attachment. Cell spreading and differentiation (adipogenic vs. osteogenic) studies are ongoing at the time of abstract submission. Ultimately, this work lays the synthetic groundwork for a new synthetic platform for LC biomaterials that can be adapted to include biological molecules as well as investigates LC network utility as a dynamic culture substrate. Please click Additional Files below to see the full abstract