Relationship Between the Carbonation Depth and Microstructure of Concrete Under Freeze-Thaw Conditions.

Concrete structures in cold regions are affected by freeze-thaw cycles (FTCs) and carbonation, which lead to the premature failure of concrete structures. The carbonation depth, relative dynamic elastic modulus (RDEM), compressive strength, porosity, and pore size distribution of concrete under FTC conditions were tested through an accelerated carbonation experiment to study the carbonation performance evolution. The freeze-thaw effect mechanism on concrete carbonation was further analyzed via the obtained relationship between carbonation depth and pore structure.

The environmental cost of tax administration: evidence from a regression discontinuity design in China.

Tax collection and management is an important factor affecting corporate pollution emissions, but currently, few studies systematically and rigorously identify its effects. Based on China's tax collection and management reform and a microenterprise database, this paper uses a regression discontinuity design model to empirically analyze the impact of tax collection and management reform on environmental pollution and the mechanism of this impact. This study found that the tax collection and management reforms have significantly increased environmental pollution.

The costs of "blue sky": environmental regulation and employee income in China.

Strict environmental regulations may change the behavioral decisions of firms. Based on the exogenous impact of the Chinese Central Government's inclusion of environmental performance in the assessment targets of municipal officials in 2007, this study uses the difference-in-difference method to explore the impact of environmental regulations on employee income. We find that (1) environmental regulations will significantly reduce the average wage level of employees in polluting industries and have no significant impact in nonpolluting industries.

Intergovernmental competition, industrial spatial distribution, and air quality in China.

As clean air is a public good, local governments play an irreplaceable role in environmental protection. This study examines how intergovernmental competition affects air quality in China. The results reveal that intergovernmental tax competition increases regional sulfur dioxide and haze emissions and worsens regional air quality, while competition in infrastructure investment does not have such effects.

pH-Responsive Hybrid Nanoparticles for Imaging Spatiotemporal pH Changes in Biofilm-Dentin Microenvironments.

Engineering highly sensitive nanomaterials to monitor spatiotemporal pH changes has rather broad applications in studying various biological systems. Intraoral/biofilm-tooth pH is the single parameter that has demonstrated accurate assessment of dental caries risk, reflecting the summative integrated outcome of the complicated interactions between three etiological factors, namely, microorganisms/biofilm, diet/carbohydrates, and tooth/saliva/host. However, there is little to no technology/system capable of accurately probing simultaneously both the micro-pH profiles in dentin tissues and acidogenic oral biofilms and examining the pathophysiologic acid attacks with high spatial/temporal resolution.

The Effect of Tumour Necrosis Factor-α on Periodontal Ligament Stem Cell Differentiation and the Related Signaling Pathways.

Periodontal regeneration plays an integral role in the treatment of periodontal diseases, with important clinical significance for the preservation and functional recovery of affected teeth. Periodontal ligament stem cells (PDLSCs), which were found in the periodontal ligament tissues possessing properties of pluripotency and self-renewing, could repair damaged periodontium with great promise. However, in a chronic inflammatory micro-environment, these cells suffered from reduced capacity to differentiate and regenerate.

The reduction of anti-cancer drug antagonism by the spatial protection of drugs with PLA-TPGS nanoparticles.

Docetaxel (DCL) and tamoxifen (TAM) individually are potent drugs in the fight against breast cancer. However when used in combination, they become antagonistic because of differential metabolism of both drugs. We reasoned that by spatially protecting them from metabolizing enzymes with poly (lactide)-D-α-tocopheryl polyethylene glycol succinate (PLA-TPGS) nanoparticles (NPs), we might reduce this drug antagonism.