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The Ultra-Wide Bandwidth (UWB) signal has received much attention due to its penetrability and high positioning accuracy with the increasing demand for indoor positioning, in which Global Positioning System (GPS) signal is challenging. In practice, there are two main problems with indoor 3D positioning based on UWB. One is that the quality of Time Difference of Arrival (TDOA) measurements varies in different observation environments. Namely, the time delay generated by Non-Line-of-Sight (NLOS) causes an enormous deviation from the real distance and cannot be well distinguished from the measurement reducing the accuracy of positioning. The other problem is that the height estimates, which are calculated using the conventional least square method, are extremely unstable due to the limitation of the Base Station (BS) layout. To address these problems, this paper presents Robust Ridge Estimation (RRE) for UWB positioning. Firstly, NLOS errors are detected, and the weights of each measurement are automatically adjusted in accordance with their quality, which is represented by the residuals between the estimated measurements and real observations. Then, the ridge estimation algorithm is applied iteratively for position estimation based on a robust estimation framework, which updates the weight of the measurements at each iteration. This approach transforms unbiased estimation to biased estimation by adding constraints that minimize the weighted quadratic sum of some parameters. As a result, the impact of NLOS can be reduced. The experimental result shows an improvement of RMSE in positioning with 45.71% when compared with ridge estimation in an NLOS/Line-of-Sight (LOS) mixed environment and an increase of robustness to NLOS with 56.11%. [ABSTRACT FROM AUTHOR]

Nonalcoholic fatty liver disease (NAFLD) refers to a pathological condition of hepatic steatosis. Insulin resistance is believed to be the key mechanism mediating initial accumulation of fat in the liver, resulting in hepatic steatosis. Kukoamine A (KuA), a spermine alkaloid, is a major bioactive component extracted from the root barks of Lycium chinense (L. chinense) Miller. In the current study, we aimed to explore the possible effect of KuA on insulin resistance and fatty liver. We showed that KuA significantly inhibited the increase of fasting blood glucose level and insulin level, and the glucose levels in response to glucose and insulin load in HFD-fed mice, which was in a dose-dependent manner. KuA dose-dependently decreased the histological injury of liver, levels of hepatic triglyceride (TG), and serum AST and ALT activities in HFD-fed mice. The increase of serum levels of TNFɑ, IL-1β, IL-6 and C reactive protein in HFD-fed mice was inhibited by KuA. HFD feeding-induced increase of hepatic expression of Srebp-1c and its target genes, including fatty acid synthase (FAS) and acetyl CoA carboxylase 1 (ACC1), was significantly inhibited by KuA. Moreover, upregulation of Srebp-1c notably inhibited KuA-induced improvement of insulin-stimulated glucose uptake, decrease of lipid accumulation and H 2 O 2 level in palmitic acid-treated AML-12 cells. In conclusion, we reported that KuA inhibited Srebp-1c and downstream genes expression and resulted in inhibition of lipid accumulation, inflammation, insulin resistance and oxidative stress. Overall, our results provide a better understanding of the pharmacological activities of KuA against insulin resistance and hepatic steatosis. [ABSTRACT FROM AUTHOR]

Abstract: Human placenta-derived mesenchymal stem cells (hPMSCs) have been shown to possess immunosuppressive effects against T cells and support the expansion of hematopoietic stem/progenitor cells (HSPCs) from umbilical cord blood (UCB). However, the characteristics of hPMSCs compared with human bone marrow-derived mesenchymal stem cells (hBMSCs) are not fully understood. Here, we show that hPMSCs have similar regulatory effects on T cell activation, proliferation and cytokine secretion as hBMSCs and demonstrate that PDL1 and B7H4, negative co-stimulatory molecules, are involved in the T cell immunosuppressive activities of hPMSCs and hBMSCs, respectively. hPMSCs efficiently enhanced the expansion of CD34+ cells from UCB compared with hBMSCs. Furthermore, hPMSCs maintained the expression of adhesion molecules (CD11a, CD44 and CD49e) in CD34+ cells. Similar effects were observed for both hPMSCs and hBMSCs on CD34+ cell chemotaxis and cytokine production, such as SDF-1α, IL-6 and SCF. Therefore, hPMSCs may be an ideal alternative source of hBMSCs for basic research and clinical applications, which may be significant in future efforts to explore the potential clinical utility of hPMSCs. [Copyright &y& Elsevier]

Abstract: In this paper, we report a simple strategy for fabricating hollow CaCO3 microspheres. We employed poly (ethylene glycol) (PEG) and sodium dodecyl sulfate (SDS) in one system, as a template for the controlled growth of hollow CaCO3 microspheres. It suggests that the PEG–SDS complex micelles play a key role in controlling the growth of biominerals. The variation of polymer molecular weight drastically changed the morphology and polymorph of the obtained CaCO3. These results also present a facile route to biomimetic inorganic synthesis. [Copyright &y& Elsevier]

Abstract: A new hierarchical CuO architecture consisting of densely packed nanoplates and nanoribbons was directly fabricated on Cu foils via a room-temperature solution-immersion process. The architectures resembled cabbages both in the shape and structure, and the plates and ribbons served as the leafstalks and leaves of cabbages, respectively. By carefully monitoring the growth stages, it was found that self-assembled CuO nanoplates could be firstly formed on the Cu foils, and then CuO tiny flexible nanoribbons were grown from the edges of fresh plates. The effect of NaOH concentration on the morphology of CuO structures was discussed. Importantly, stable superhydrophobicity (contact angle CA=155°), independent of pH value of the water droplets, was successfully observed for CuO microcabbages after modification. The wettability of other CuO micro- and nanoscale hierarchical surface structures fabricated using various NaOH concentrations was also presented. The realization of superhydrophobic bionic surfaces with a new hierarchical morphology of CuO will shed new insights in both the synthesis and application fields. [Copyright &y& Elsevier]

Abstract: ZnO nanorod arrays with different morphologies have been synthesized on the zinc foil via a simple hydrothermal method which is both a convenient and inexpensive process. The key influencing factors including the solution concentration and the reaction time are all studied and compared carefully. Based on our investigation, it is found that the morphologies of ZnO crystals could be controlled and the transition of different morphologies is also realized successfully with the growing reaction time. Furthermore, the as-grown ZnO nanorods are single crystalline with a wurtzite structure. Finally, a reasonable mechanism to explain the different crystal morphologies is also discussed in detail. [Copyright &y& Elsevier]

Abstract: A simple aqueous solution route has been successfully employed to prepare large-scale arrays of ZnO nanorods on the zinc foil without the assistance of any template, oxidant or coating of metal oxide layers. It is found that the growth of ZnO nanorod arrays with different densities, diameters and morphologies is dependent on the ammonia concentration and zinc precursor. The different morphologies of the ZnO nanostructures attained with or without adding Zn2+-contained salt in the alkaline solution are compared in the paper. The possible growth mechanism concerning the growth of the different ZnO nanocrystal morphologies is also discussed. [Copyright &y& Elsevier]