Study on the spatial and temporal correlation and allometric growth mechanism between population aging and carbon emissions in China.

Population aging and carbon emissions are critical issues for China's development. As an enormous complex system, the population and the carbon emission development process have non-negligible differences in time, space, and speed. Therefore, this paper first demonstrates the spatial and temporal correlation between population aging and carbon emissions from 1995 to 2020, then uses the allometric growth analysis model to make a cross-sectional temporal comparison and a vertical spatial comparison of the relationship and development rate of the two, and finally uses the ridge regression model to determine the forces and interaction mechanisms of the factors influencing the relationship between population aging and carbon emissions at allometric rates. The results show that (1) China has a long-term positive temporal correlation effect relationship between population aging and carbon emissions from 1995 to 2020, and the overall correlation is high. The spatial correlation intensity between population aging and carbon emissions varies significantly across Chinese provinces, with a general spatial distribution trend of high in the south, low in the north, and prominent in the center. (2) China's population aging and carbon emissions mainly show a negative allometric growth type of relationship, i.e., a strong trend of population aging expansion and a strengthening trend of carbon emission system shrinking. The number of provinces with negative allometric growth is gradually increasing, mainly in North, East, Central, and Southwest China. (3) From 1995-2010 period to the 2011-2020 period, the influence of the factors of the population, production, and economic dimensions on the population aging index and the carbon emission allometric scalar index gradually weakened, and the influence of the consumption and technology dimensions increased significantly. The factors on the population and consumption side of the dimension mainly contribute to the expansion of carbon emissions and drive positive allometric growth. The production side, the economic structure, and technology dimension factors drive negative allometric growth. The paper fully explores the bidirectional correlation, differential development trend, and interaction mechanism between the two systems of population and carbon emissions and effectively compensates for the lack of research content in terms of elemental correlation, spatial and temporal connection, and speed synergy.

[Adaptability assessment of economic and environmental development of Tangshan, Hebei, China].

It is vital to explore whether the economic system adapts to the environmental system as the relationship between economy and environment becomes a gradually concerned problem. Tangshan, a typical resource-based city, was chosen to study the adaptabilities and performances of economic developments in response to environmental changes from 1992 to 2011. It was found that the economic-environmental adaptation curve of Tangshan City had an overall fluctuating and increasing tendency. The systematic adaptability kept advancing, reflecting Tangshan paid much attention to environmental development in addition to economic performances, and the two aspects became more and more coordinated. Filtering analysis of the adaptive curve with Eviews software revealed that the potential systematic coordinating index was rising continuously, however, the sum of resilience gap for 20 years was still negative, which implied that fundamental contradictions between high economic development and high energy consumption and high pollutant emission still existed. Carrying out adaptive researches not only helps people to adapt to climate changes better, but also has significances for economic and environmental coordination and sustainability research.

Watching single gold nanorods grow.

The consecutive evolution process of single gold nanorods is monitored using atomic force microscopy (AFM). The single-crystal gold nanorods investigated are grown directly on surfaces to which gold seed particles are covalently linked. The growth kinetics for single nanorods is derived from the 3D information recorded by AFM. A better understanding of the seed-mediated growth mechanism may ultimately lead to the direct growth of aligned nanorods on surfaces.

[Coordinated evolvement of dynamic coupling between economic and environmental systems in Shenyang Metropolitan area].

By using coupling coordinated degree model, scissors difference methods, and coupling degree model, this paper analyzed the coupling coordinated status, development speed difference, and coupling development trend between economic and environmental systems in Shenyang Metropolitan Area in 1990-2009. In the study period, the coupling level of the relations between economic and environmental development was ascending, with the coupling degree increased from 0.42 to 0.89, which reflected the more and more harmonious relationships between economy and environment. The decrease of economic development speed and the increase of environmental construction speed reduced the scissor difference of the two systems from 0.63 degrees to 0.22 degrees, demonstrating the contribution of the economic development speed to the coupling coordinated status. The coupling degree between the economic and environmental systems stretched across in a [45 degrees, 90 degrees] region, which meant that the two systems were in a co-developing status. As the discrepancy between the development speeds of the two systems became smaller, the coupling degree was closer to 45 degrees, and the two systems were becoming better coordinated.

Surface modification of poly(D,L-lactic-co-glycolic acid) nanoparticles with protamine enhanced cross-presentation of encapsulated ovalbumin by bone marrow-derived dendritic cells.

Cross-presentation is the key process in stimulation of cytotoxic T lymphocyte (CTL) immune response in eliminating many infectious diseases and tumors. Previous studies have shown that surface modification of poly(D,L-lactic-co-glycolic acid) (PLGA) particles with polycations enhanced their adjuvant ability resulting in a strong antibody response to the encapsulated antigen. However, the in vitro cross-presentation by protamine-coated PLGA nanoparticles (NPs) has not been addressed yet. In this study, a model antigen ovalbumin (OVA) was encapsulated into PLGA nanoparticles, with (OVA-NPs/protamine) or without protamine coating (OVA-NPs). These nanoparticles were then used to stimulate murine bone marrow-derived dendritic cells (BMDCs). Flow cytometry analysis revealed an increase in endocytosis of protamine-coated PLGA nanoparticles by BMDCs at 37°C. Compared with OVA-NPs-treated BMDCs, stimulation with OVA-NPs/protamine led to significantly upregulation of CD80, CD86, and CD83, increased secretion of IL-12p70, and decreased production of IL-4 by BMDCs. Furthermore, OVA-NPs/protamine-treated BMDCs also showed an enhanced cross-presentation to B3Z T cell hybridoma in vitro. Transmission electron microscopy (TEM) study showed that protamine-coated PLGA nanoparticles escaped from lysosomes through the interaction with lysosomal membrane. These results demonstrated that protamine-coated PLGA nanoparticles could enhance the cross-presentation of encapsulated exogenous antigen by facilitating antigen uptake and lysosomal escape, suggesting the feasibility to be a potent adjuvant for cellular vaccines.