Effects of Climate Change on Vegetation in Desert Steppe Inner Mongolia

As the largest ecosystem in China, Grassland not only provides abundant natural resources for the regional economic development, but also safeguards the environment of north China as it acts as an ecological protective screen. However, because of the arid and semi-arid regions, most grassland are limited by climate seriously, changes in precipitation and temperature can affect the community composition and primary productivity within and through grassland ecosystems. Based on the long period climate data and observational data of vegetation in DAMAOQI grassland Inner Mongolia, the study analyzed the climate change and its effect on community properties by using the linear trend method, etc. The results showed that climate change presented increasing temperature and fluctuant precipitation in the last decades. More precipitation could increase species diversity, and precipitation was better than the temperature for diversity exponents. According to these results, the strategy of soil and water conservation ecological rehabilitation would be provided to respond to the climate change. Increase the vegetation coverage and alleviate soil erosion relying on the self-restoration capability of natural ecosystems under ecological theories, erect a development system on the balance among the water, the forage and the animal. Transform those traditional extensive methods and enhance family farms vigorously by local conditions, the most important of which is water resource. The strategy of ecological rehabilitation advocates in the soil and water conservation and the ecological construction can be adjusted to the aim that establishes a conservation-minded society and a friendly environment society.

In situ synthesis of red fluorescent gold nanoclusters with enzyme-like activity for oxidative stress amplification in chemodynamic therapy

Chemodynamic therapy (CDT) has attracted tremendous interest in cancer therapy because it is independent of oxygen and photoirradiation. However, the therapeutic efficacy of CDT is restricted by insufficient H_(2)O_(2) levels in tumor cells. Herein, employing endogenous GSH as a template and cationic polymeric chitosan (CS) as crosslinker and stabilizer exhibiting easy cell uptake, red luminescent gold nanoclusters (denoted CS-GSH@AuNCs) were successfully synthesized in HeLa cells. The in situ synthesized CS-GSH@AuNCs exhibited both superoxidase dismutase (SOD) and peroxidase (POD)-like activity, which could promote the production of H_(2)O_(2) from superoxide anion radicals (O_(2)^(·-)) and then ^(·)OH. The combination of GSH elimination and H_(2)O_(2) elevation boosted the generation of ^(·)OH, which could trigger cancer cell apoptosis and death. The enzyme-like activity of CS-GSH@AuNCs could be effectively activated under acidic conditions, and showed a high killing effect on tumor cells but minimal toxicity to normal cells. The developed GSH consumption and ^(·)OH promotion theranostic platform is an innovative route for enhanced CDT by the amplification of oxidative stress.