Preeclampsia associated changes in volume density of fetoplacental vessels in Chinese women and mouse model of preeclampsia.

INTRODUCTION: Preeclampsia (PE) is associated with abnormal placental vascular structure. However, the volume density of fetoplacental vessels in PE remains unclear. Additionally, manually annotated CT angiography, which is widely used to analyze placental vessels, has issues regarding inaccuracy. Thus, computer-aided CT angiography for analyzing the volume density of fetoplacental vessels would facilitate the understanding of PE pathogenesis. METHODS: We performed computer-aided CT angiography to compare differences in placentas among 17 women with PE and 34 normotensive women. The contrast ratio in CT angiography was significantly enhanced using a three-dimensional (3-D) Hessian matrix algorithm. The PE-like mouse model was established by administration of 125 mg/kg/day NG-nitro-l-arginine methyl ester (l-NAME) for 10 days. The presence of endothelial marker CD31 was confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC). The expression of angiogenic factors (PlGF, VEGFA, and sFlt1) in placentas was detected using qRT-PCR and western blotting. RESULTS: The volume density in fetoplacental vessels and CD31 expression were significantly reduced in women with PE and l-NAME-induced mice. Additionally, the downregulation of angiogenic factors (PlGF/VEGFA) and upregulation of an anti-angiogenic factor (sFlt1) were determined in a mouse model. DISCUSSION: Contrast-enhanced CT angiography with the aid of a 3-D Hessian matrix algorithm was performed. PE significantly affects the formation of vascular vessels, resulting in a lower volume density of fetoplacental vessels in humans and mice. This may be explained by the abnormal release of angiogenic factors during PE.

Retroreflection from a single layer of electromagnetic Helmholtz cavities based on magnetic symmetric dipole modes.

We demonstrate a new electromagnetic mode which is formed by the dynamic interaction between a magnetic quadrupole mode and an electric monopole mode in a two-dimensional electromagnetic Helmholtz cavity. It is termed a magnetic symmetric dipole mode since it shares similarity with a magnetic dipole mode in the sense that their radiation is both overwhelmingly dominant in the forward and backward directions with respect to the incident wave. However, the phase distribution in the two radiation directions is symmetric, in stark contrast to the antisymmetry of magnetic dipole modes. When the Helmholtz cavities are arranged in a line, the incident wave will be reflected back to the source, in other words, retroreflection occurs because of the peculiar properties of magnetic symmetric dipole modes. We show that the retroreflection is quite robust against the disorder of the orientation angle of Helmholtz cavities and there exists a wide tolerance for wavelength and the outer radius of the cavity. With low fabrication demands, this might offer a feasible solution for the design of ultrathin retroreflectors towards device miniaturization and the realization of multiplexing holography.

Income related inequality and influencing factors: a study for the incidence of catastrophic health expenditure in rural China.

BACKGROUND: Catastrophic health expenditure (CHE) puts a heavy disease burden on patients' families, aggravating income-related inequality. In an attempt to reduce the financial risks of rural families incurring CHE, China began the New Rural Cooperative Medical System (NCMS) on a trial basis in 2003 and has raised the reimbursement rates continuously since then. Based on statistical data about rural families in sample area of Jiangsu province, this study measures the incidence of CHE, analyzes socioeconomic inequality related to CHE, and explores the influences of the NCMS on the incidence of CHE. METHODS: Statistical data were acquired from two surveys about rural health care, one conducted in 2009 and one conducted in 2010. In 2009, 1424 rural families were analyzed; in 2010, 1796 rural families were analyzed. An index of CHE is created to enable the evaluation of the associated financial risks. The concentration index and concentration curve are used to measure the income-related inequality involved in CHE. Multiple logistic regression is utilized to explore the factors that influence the incidence of CHE. RESULTS: The incidence of CHE decreased from 13.62% in 2009 to 7.74% in 2010. The concentration index of CHE was changed from -0.298 (2009) to -0.323 (2010). Compared with rural families in which all members were covered by the NCMS, rural families in which some members were not covered by the NCMS had a lower incidence of CHE: The odds ratio is 0.65 with a 95% confidence interval of 0.43 to 1.00. For rural families in which all members were covered by the NCMS, the increase in reimbursement rates is correlated to the decline in the incidence of CHE if other influencing factors were controlled: The odds ratio is 0.48 with a 95% confidence interval of 0.36 to 0.64. CONCLUSIONS: Between 2009 and 2010, the incidence rate of CHE in the sampled area decreased sharply, CHE was more concentrated among least wealthy and inequality increased during study period. As of 2010, the poorest rural families still had high risk of experiencing CHE. For rural families in which all members are covered by the NCMS, the rise in reimbursement rates reduces the probability of experiencing CHE.