Distribution of plutonium isotopes in soils between two nuclear test sites: Semipalatinsk and Lop Nor.

Plutonium (Pu) has attracted attention as an environmental tracer due to its radiotoxicity and the possibility of sources linked with nuclear accidents in recent years. Plutonium isotopes (239,240Pu) were detected at trace levels in soils collected from the Xinjiang region located between the Semipalatinsk nuclear test site and China's Lop Nor nuclear test site. Little is known regarding the spatial variation of 239,240Pu in soils from this region. This study reports the use of Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICP-MS) methods to distinguish between Pu isotopes derived from global fallout and nuclear weapon tests. We found that the 239,240Pu activity concentrations ranged from 0.035 to 1.338 mBq/g; the 240Pu/239Pu atomic ratios were 0.157-0.223 with a weighted average of 0.180 ± 0.002, corresponding with the expected average global fallout ratio of 0.180 ± 0.014. This indicated that global fallout is the major source of Pu in the study region. The 239,240Pu inventories in these soils ranged from 23.67 to 222.7 Bq/m2, corresponding with those from other areas in China and other countries within the latitude range. Our Pu isotope data was supplemented with other published Pu data for soils collected in the vicinity of the Semipalatinsk nuclear test site and Lop Nor nuclear test site. Results indicate that 239,240Pu inventories and 240Pu/239Pu atomic ratios in soils exhibit large variations with distance from the Semipalatinsk nuclear test site. High deposition and accumulation of Pu, and low 240Pu/239Pu ratios were observed in close-in fallout and downwind regions of the Semipalatinsk nuclear test site and China's Lop Nor nuclear test site.

Effects of angiopoietin-1 on inflammatory injury in endothelial progenitor cells and blood vessels.

Endothelial progenitor cells (EPCs) and angiopoietin-1 (Ang-1) play important roles in vasculogenesis and angiogenesis, respectively. Thus, targeting both aspects of cardiovascular tissue regeneration may offer promising therapeutic options for cardiovascular disorders. To this end, we constructed a lentiviral vector (pNL) with the Ang-1 gene and transfected EPCs with it (Ang-1-EPCs) to investigate vasculogenesis in both cellular and animal models. Compared to controls, intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) increased significantly in both untreated EPCs and in the pNL vector group. After Ang-1 transcription, ICAM-1 and VCAM-1 decreased considerably in those treatment groups. Ang-1-modified EPCs alleviated inflammatory responses induced by tumor-necrosis factor-α (TNF-α) in vitro. Moreover, Ang-1-EPC implantation inhibited neointimal hyperplasia after balloon catheter injury in rats, dramatically diminishing the intimal-media (I/M) ratio and decreasing the neointimal area. Proliferating cell nuclear antigen expression in the Ang-1-EPC group was lower than the EPC non-treatment group as well, suggesting that Ang-1-EPC improved cell survival during inflammation and promoted endothelialization in damaged blood vessels.