A Two-Dimensional CA Traffic Model with Dynamic Route Choices Between Residence and Workplace

The Biham, Middleton and Levine (BML) model is extended to describe dynamic route choices between the residence and workplace in cities. The traffic dynamic in the city with a single workplace is studied from the velocity diagram, arrival time probability distribution, destination arrival rate and convergence time. The city with double workplaces is also investigated to compared with a single workplace within the framework of four modes of urban growth. The transitional region is found in the velocity diagrams where the system undergoes a continuous transition from a moving phase to a completely jamming phase. We perform a finite-size scaling analysis of the critical density from a statistical point of view and the order parameter of this jamming transition is estimated. It is also found that statistical properties of urban traffic are greatly influenced by the urban area, workplace area and urban layout.Comment: 18 pages, 13 figure

Arbitrary Shape Electromagnetic Transparent Device Based on Laplace’s Equation

Transparent device is deliberately-designed electromagnetic structure that is transparent to electromagnetic wave. It can be used as a radome structure which is capable of protection antenna inside without sacrificing its performance. In this paper, two-dimensional (2D) arbitrary shape electromagnetic transparent device is designed based on transformation optics. Laplace’s equation is adopted to construct the coordinate mapping between the original space and the transformed space. The design method is flexibly extended to three-dimensional (3D) case, which greatly enhances the applicability of transparent device. The protection of a horn antenna is taken as an example to show the effectiveness of the transparent device. Since the performance of the transparent device is independent on the inner antenna, it can be designed separately. Full-wave simulations are made to validate the results

Expression of hypoxia inducible factor-1α and vascular endothelial growth factor-C in human chronic periodontitis

AbstractBackground/purposeEvidence shows that there is a relationship between hypoxia and inflammatory response in periodontitis. Hypoxia-inducible factor (HIF)-1α is a major regulator of energy homeostasis and cellular adaptation to low oxygen stress. Although experimental results demonstrate an association between HIF-1α and vascular endothelial growth factor (VEGF)-C in tumor angiogenesis, the role of HIF-1α and VEGF-C in the pathogenesis of periodontitis is still ambiguous. So far, limited attention has been given to the role of hypoxia and VEGF-C in periodontitis. The present study aimed to investigate the expression and distribution of HIF-1α and VEGF-C in gingival tissue samples from patients with different stages of chronic periodontitis and healthy individuals.Materials and methodsA total of 56 samples were involved in this study, including moderate chronic periodontitis (n = 20), advanced chronic periodontitis (n = 20), and healthy control tissues (n = 16). The gingival specimens were stained with hematoxylin and eosin for histopathology. The expression of HIF-1α and VEGF-C in gingival tissues was detected by immunohistochemical staining.ResultsHIF-1α and VEGF-C were found in gingival tissues from patients with different stages of chronic periodontitis as well as healthy control tissues. HIF-1α protein was expressed mainly in the epithelial layer of gingival tissues, and VEGF-C protein was mostly located in the connective tissue papilla of gingival tissues. Compared with healthy controls, the expression of HIF-1α and VEGF-C in chronic periodontitis groups was significantly higher (P < 0.01), and the density of HIF-1α and VEGF-C in advanced chronic periodontitis group was even significantly higher than that in the moderate chronic periodontitis group (P < 0.01).ConclusionOur results suggest that the expression of HIF-1α and VEGF-C increased with severity of periodontitis. So, we conclude that HIF-1α may play an important role in the pathophysiology of human periodontitis and may be related to the function of VEGF-C during periodontitis

Protective effect of liquiritin on corticosterone-induced neurotoxicity in PC12 cells

Purpose: To determine the protective effects of liquiritin on corticosterone-induced neurotoxicity in rat pheochromocytoma (PC12) cells.Methods: Neurotoxicity in PC12 cells was induced by different concentrations of corticosterone. Proliferation of PC12 cells was evaluated using CCK8 assay kits, while apoptosis was determined by flow cytometry.Results: The results indicate that corticosterone inhibited the proliferation of PC12 cells time- and dosedependently. The inhibitory effect (0.2 mM) was ameliorated by liquiritin. Furthermore, the cell apoptosis rate and protein level of caspase 3 in PC12 cells induced by corticosterone were ameliorated by liquiritin (1 and 2 mg/mL) treatment. Moreover, the protective effect of liquiritin (2 mg/mL) on corticosterone induced neurotoxicity in PC12 cells was weakened by K252a (the specific TrkB inhibitor) treatment. In addition, the protein level of brain-derived neurotrophic factor (BDNF) and (tyrosine-kinase receptor) TrkB showed a reverse trend to caspase 3.Conclusion: Liquiritin shows protective effects against neurotoxicity induced by corticosterone in PC12 cells, and these effects are exerted via up-regulating BDNF/TrkB signaling.Keywords: Liquiritin, Antidepressant, Corticosterone, Neuroprotection, PC12 cells, BDNF/TrkB signalin

Multi-wavelength Stellar Polarimetry of the Filamentary Cloud IC5146: I. Dust Properties

We present optical and near-infrared stellar polarization observations toward the dark filamentary clouds associated with IC5146. The data allow us to investigate the dust properties (this paper) and the magnetic field structure (Paper II). A total of 2022 background stars were detected in $R_{c}$-, $i'$-, $H$-, and/or $K$-bands to $A_V \lesssim 25$ mag. The ratio of the polarization percentage at different wavelengths provides an estimate of $\lambda_{max}$, the wavelength of peak polarization, which is an indicator of the small-size cutoff of the grain size distribution. The grain size distribution seems to significantly change at $A_V \sim$ 3 mag, where both the average and dispersion of $P_{R_c}/P_{H}$ decrease. In addition, we found $\lambda_{max}$ $\sim$ 0.6-0.9 $\mu$m for $A_V>2.5$ mag, which is larger than the $\sim$ 0.55 $\mu$m in the general ISM, suggesting that grain growth has already started in low $A_V$ regions. Our data also reveal that polarization efficiency (PE $\equiv P_{\lambda}/A_V$) decreases with $A_V$ as a power-law in $R_c$-, $i'$-, and $K$-bands with indices of -0.71$\pm$0.10, -1.23$\pm$0.10 and -0.53$\pm$0.09. However, $H$-band data show a power index change; the PE varies with $A_V$ steeply (index of -0.95$\pm$0.30) when $A_V < 2.88\pm0.67$ mag but softly (index of -0.25$\pm$0.06) for greater $A_V$ values. The soft decay of PE in high $A_V$ regions is consistent with the Radiative Aligned Torque model, suggesting that our data trace the magnetic field to $A_V \sim 20$ mag. Furthermore, the breakpoint found in $H$-band is similar to the $A_V$ where we found the $P_{R_c}/P_{H}$ dispersion significantly decreased. Therefore, the flat PE-$A_V$ in high $A_V$ regions implies that the power index changes result from additional grain growth.Comment: 31 pages, 17 figures, and 3 tables; accepted for publication in Ap