Cobalt protoporphyrin-induced nano-self-assembly for CT imaging,magnetic-guidance,and antioxidative protection of stem cells in pulmonary fibrosis treatment

Mesenchymal stem cells(MSCs)transplantation is a promising approach for pulmonary fibrosis(PF),however it is impeded by several persistent challenges,including the lack of long-term tracking,low retention,and poor survival of MSCs,as well as the low labeling efficiency of nanoprobes.Herein,a cobalt protoporphyrin IX(CoPP)aggregation-induced strategy is applied to develop a multifunctional nano-self-assembly(ASCP)by combining gold nanoparticle(AuNPs),superparamagnetic iron oxide nanoparticles(SPIONs),and CoPP through a facile solvent evaporation-driven approach.Since no additional carrier materials are employed during the synthesis,high loading efficiency of active ingredients and excellent biocompatibility are achieved.Additionally,facile modification of the ASCPs with bicyclo[6.1.0]nonyne(BCN)groups(named as ASCP-BCN)enables them to effectively label MSCs through bioorthogonal chemistry.The obtained ASCP-BCN could not only help to track MSCs with AuNP-based computed tomography(CT)imaging,but also achieve an SPIONs-assisted magnetic field based improvement in the MSCs retention in lungs as well as promoted the survival of MSCs via the sustained release of CoPP.The in vivo results demonstrated that the labeled MSCs improved the lung functions and alle-viated the fibrosis symptoms in a bleomycin–induced PF mouse model.Collectively,a novel ASCP-BCN multi-functional nanoagent was developed to bioorthogonally-label MSCs with a high efficiency,presenting a promising potential in the high-efficient MSC therapy for PF.

Quantitative research of incentive effects of heat-metering policy on energy-saving behavior in Tianjin

To promote energy efficiency and emission reduction, the Chinese government has invested large amounts of resources in heat-metering reform over the past decade. However, heat-metering, which can reduce energy consumption by 15% at least in developed countries, is still not well known in China. This paper quantitatively analyzed the arousal effect of heat-metering policy on occupancy behavior regarding energy saving utilizing statistics method based on measured data of heating energy consumption of approximately 20000 users from 2008 to 2012 in Tianjin. The statistical data showed significant difference on energy consumption between users based on metering and based on area. The energy-saving rate in the heating season increased significantly from 4.11% in 2008-2009 to 10.27% in 2011-2012 as the implement of the heat-metering policy. The difference in energy-saving according to various outdoor temperatures showed that the energy-saving of occupancy behavior was more significant in a warm season than in a cold season. It also showed that the impact of heat-metering policy would be more pronounced in generally insulated buildings （15.55%） than in better insulated units （6.45%）. Besides, this paper proposed some feasible suggestions for the formulation and implementation of heat-metering policy in northern heating areas of China.