No abstract

To evaluate the changes in extreme climatic events in the Feilaixia catchment in South China, the spatial and temporal distributions of extreme climate indices trends during 1969-2011 were investigated. With quality control and homogeneity assessment, daily maximum and minimum surface air temperature from 11 meteorological stations and daily precipitation from 24 rainfall stations were used. Eight indices of extreme temperature and six indices of extreme precipitation were chosen. Trends were calculated using Sen's slope estimator. Statistical significance of trends was checked with the Mann-Kendall method. High correlations were found between the mean annual temperature and temperature extremes, as well as between the annual total precipitation and precipitation extremes in most cases. The analyses of extreme temperature indices detected significant and stable trends in the majority of the stations. The strongly stable downward trends in cold extremes and the strongly stable upward trends in hot extremes were recorded in the whole region, except for in some small areas primarily located in the central part of the region. In contrast, significant and stable positive trends were sporadically recorded for precipitation extremes in the study area during 1969-2011, which predominantly occurred in the northern part of the region. Furthermore, the positive trends were much more frequent than the negative trends in most extreme precipitation indices. There were significant and stable trends recorded in most of the average temperature extremes, whereas insignificant and unstable trends were found for most of the average precipitation extremes.

Human multipotent stem cell-based therapies have shown remarkable potential in regenerative medicine and tissue engineering applications due to their abilities of self-renewal and differentiation into multiple adult cell types under appropriate conditions. Presently, human multipotent stem cells can be isolated from different sources, but variation among their basic biology can result in suboptimal selection of seed cells in preclinical and clinical research. Thus, the goal of this study was to compare the biological characteristics of multipotent stem cells isolated from human bone marrow, placental decidua basalis, and urine, respectively. First, we found that urine-derived stem cells (USCs) displayed different morphologies compared with other stem cell types. USCs and placenta decidua basalis-derived mesenchymal stem cells (PDB-MSCs) had superior proliferation ability in contrast to bone marrow-derived mesenchymal stem cells (BMSCs); these cells grew to have the highest colony-forming unit (CFU) counts. In phenotypic analysis using flow cytometry, similarity among all stem cell marker expression was found, excluding CD29 and CD105. Regarding stem cell differentiation capability, USCs were observed to have better adipogenic and endothelial abilities as well as vascularization potential compared to BMSCs and PDB-MSCs. As for osteogenic and chondrogenic induction, BMSCs were superior to all three stem cell types. Future therapeutic indications and clinical applications of BMSCs, PDB-MSCs, and USCs should be based on their characteristics, such as growth kinetics and differentiation capabilities.

Imaging-guided stimuli-responsive delivery systems based on nanomaterials for cancer theranostics have been recognized as promising alternatives to traditional therapies in clinic. How to integrate multiple response-mediated nanoproperty (i.e., charge, size, or stability) transitions into a cascaded manner to overcome multistage biological barriers which usually demand different and even opposing nanoproperties in each stage is still a challenge. Herein, a multistage and cascaded responsive theranostic nanoplatform for imaging-traceable TRAIL gene precise delivery was prepared by a cleavable PEGylated shell and a fluorescent carbon dot (CD)-based core. The CDs as the core were prefunctionalized with polyethylenimine end-capped disulfide-bond-bearing hyperbranched poly­(amido amine) (HPAP), endowing the CDs with enhanced fluorescent quantum yield (27%), intracellular degradability, and efficient gene delivery capability. The shell was fabricated by dimethylmaleic acid modification of mPEG-PEI600 copolymer and exhibited tumor microenvironment-triggered charge reversal, leading to the shell detachment from the core at the tumor site. The nanoplatform with cascaded responsive property displays prolonged blood circulation time benefiting from PEGylated shielding once being injected into blood, subsequently effective accumulation at tumor tissues from blood induced by the elevated EPR effect resulting from the microenvironment-driven synchronous charge conversion and size shrinkage, and finally controlled gene release in tumor cell cytosol facilitated by glutathione-triggered HPAP degradability. In vitro and in vivo assays demonstrated that such a blood–tissue–cell cascaded responsive nanoplatform not only possessed imaging-trackable tumor-specific delivery ability but also exhibited enhanced and selective antitumor activity through TRAIL-mediated apoptosis as well as excellent biocompatibility. This study provides a multifunctional integration strategy, paving the way for designing novel theranostic nanomedicines on the basis of precision medicine.