Wireless Fractal Cellular Networks

With the seamless coverage of wireless cellular networks in modern society, it is interesting to consider the shape of wireless cellular coverage. Is the shape a regular hexagon, an irregular polygon, or another complex geometrical shape? Based on fractal theory, the statistical characteristic of the wireless cellular coverage boundary is determined by the measured wireless cellular data collected from Shanghai, China. The measured results indicate that the wireless cellular coverage boundary presents an extremely irregular geometrical shape, which is also called a statistical fractal shape. Moreover, the statistical fractal characteristics of the wireless cellular coverage boundary have been validated by values of the Hurst parameter estimated in angular scales. The statistical fractal characteristics of the wireless cellular coverage boundary can be used to evaluate and design the handoff scheme of mobile user terminals in wireless cellular networks.Comment: 16 pages, 4 figure

Methylprednisolone alleviates limb damage in rat models with high-pressure injection injuries of lower limbs

Objective To study the intervention effect of methylprednisolone(MP) on high pressure injection injuries(HPII) of lower limbs of rats. Methods Thirty rats were randomly divided into control group, model group (high-pressure injection injury model) and treatment group (tail vein injection of MP 30 mg/kg). After 6 hours, the jet area and limb circulation were observed, blood vessels, nerve and muscle tissues were examined by HE staining microscopy. Liver index was calculated and serum TNF-α, IL-1β and IL-6 were tested by ELISA. Comparison between multiple groups was performed by One-way Anova. Results Compared with the control group, limb circulation , blood vessels, nerves and muscles were significantly damaged.The liver index decreased while the serum content of TNF-α, IL-1β, and IL-6 all increased significantly (P＜0.05). Compared with the model group, the above indicators improved significantly in the treatment group(P＜0.05). Conclusions Injection of MP after high-pressure injection injuries can alleviate limb damage, reduce liver load and improve serum inflammatory markers of injured rats

Tourism Potential of Agricultural Heritage Systems

Traditional agricultural systems are threatened world-wide mainly due to the introduction of modern agricultural techniques and the emigration of farm labourers from remote rural villages. The objective of the programme 'Globally Important Agricultural Heritage Systems' (GIAHS), initiated by the Food and Agriculture Organization (FAO) of the United Nations in 2002, is dynamic conservation of traditional agricultural systems. This article addresses the definition and content of agricultural heritage systems and discusses conservation options in the light of developing rural tourism. An explorative survey was conducted in Longxian village, situated in Zhejiang Province, southern China, focusing on the tourism potential of a typical Rice-Fish Agricultural System. The identification of heritage resources is a first step in the process of transforming an agricultural landscape into a cultural tourism landscape. However, the future of these landscapes is in the hands of a range of stakeholders and depends on their capacity to manage, in a sustainable way, tourism development strategies alongside conservation policies

FOXM1 promotes hepatocellular carcinoma progression by regulating KIF4A expression

Abstract Background Forkhead box M1 (FOXM1) is a proliferation-associated transcription factor of the forkhead box proteins superfamily, which includes four isoforms FOXM1a, b, c, and d. FOXM1 has been implicated in hepatocellular carcinoma (HCC) progression, but the underlying molecular mechanism remains elusive. In this study, we aim to clarify the molecular basis for FOXM1-mediated HCC progression. Methods Bioinformatic analysis was used to explore the differentially expressed genes predicting HCC proliferation. The expression of FOXM1 and kinesin family member (KIF)4A was confirmed by western blotting and immunohistochemistry in HCC tissues. Kaplan-Meier survival analysis was conducted to analyze the clinical impact of FOXM1 and KIF4A on HCC. The effect of FOXM1 on the regulation of KIF4A expression was studied in cell biology experiments. The interaction between KIF4A and FOXM1 was analyzed by chromatin immunoprecipitation and luciferase experiments. A series of experiments was performed to explore the functions of FOXM1/KIF4A in HCC progression, such as cell proliferation, cell growth, cell viability, and cell cycle. A xenograft mouse model was used to explore the regulatory effect of FOXM1-KIF4A axis on HCC tumor growth. Results FOXM1 and KIF4A were overexpressed in human primary HCC tissues compared to that in matched adjacent normal liver tissue and are significant risk factors for HCC recurrence and shorter survival. We found that KIF4A was dominantly regulated by FOXM1c among the four isoforms, and further identified KIF4A as a direct downstream target of FOXM1c. Inhibiting FOXM1 decreased KIF4A expression in HCC cells, whereas its overexpression had the opposite effect. FOXM1-induced HCC cell proliferation was dependent on elevated KIF4A expression as KIF4A knockdown abolished FOXM1-induced proliferation of HCC cells both in vitro and in vivo. Conclusion The FOXM1–KIF4A axis mediates human HCC progression and is a potential therapeutic target for HCC treatment

Influence of Nickel Doping on Ultrahigh Toluene Sensing Performance of Core-Shell ZnO Microsphere Gas Sensor

As a volatile organic compound, toluene is extremely harmful to the environment and human health. In this work, through a simple one-step solvothermal method, Ni-doped ZnO sensitive materials (0.5, 1, and 2 at% Ni-doped ZnO) with a core-shell morphology were synthesized for the first time for toluene gas detection. The sensing test results showed that the sensor based on 1 at% Ni-doped ZnO exhibited the best toluene sensing performance. The response was up to 210 to 100 ppm toluene at 325 °C. The sensor exhibited high selectivity, fast response/recovery characteristics (2/77 s), and low detection limit (500 ppb, 3.5). Furthermore, we carried out molecular-level research on the sensitive material prepared in this experiment by various characterization methods. The SEM characterization results showed that ZnO and Ni-doped ZnO possessed the core-shell morphology, and the average grain size decreased with the increase in the Ni doping content. The UV–Vis test showed that the band gap of ZnO became smaller with the increase in the Ni doping amount. The enhanced toluene sensing performance of 1 at% Ni-doped ZnO could be ascribed to the structural sensitization and Ni doping sensitization, which are discussed in detail in the sensing mechanism section

Influence of Nickel Doping on Ultrahigh Toluene Sensing Performance of Core-Shell ZnO Microsphere Gas Sensor

As a volatile organic compound, toluene is extremely harmful to the environment and human health. In this work, through a simple one-step solvothermal method, Ni-doped ZnO sensitive materials (0.5, 1, and 2 at% Ni-doped ZnO) with a core-shell morphology were synthesized for the first time for toluene gas detection. The sensing test results showed that the sensor based on 1 at% Ni-doped ZnO exhibited the best toluene sensing performance. The response was up to 210 to 100 ppm toluene at 325 °C. The sensor exhibited high selectivity, fast response/recovery characteristics (2/77 s), and low detection limit (500 ppb, 3.5). Furthermore, we carried out molecular-level research on the sensitive material prepared in this experiment by various characterization methods. The SEM characterization results showed that ZnO and Ni-doped ZnO possessed the core-shell morphology, and the average grain size decreased with the increase in the Ni doping content. The UV–Vis test showed that the band gap of ZnO became smaller with the increase in the Ni doping amount. The enhanced toluene sensing performance of 1 at% Ni-doped ZnO could be ascribed to the structural sensitization and Ni doping sensitization, which are discussed in detail in the sensing mechanism section

In Situ Growth of Core–Sheath Heterostructural SiC Nanowire Arrays on Carbon Fibers and Enhanced Electromagnetic Wave Absorption Performance

Large-scale core–sheath heterostructural SiC nanowires were facilely grown on the surface of carbon fibers using a one-step chemical vapor infiltration process. The as-synthesized SiC nanowires consist of single crystalline SiC cores with a diameter of ∼30 nm and polycrystalline SiC sheaths with an average thickness of ∼60 nm. The formation mechanisms of core–sheath heterostructural SiC nanowires (SiC_nws) were discussed in detail. The SiC_nws-CF shows strong electromagnetic (EM) wave absorption performance with a maximum reflection loss value of −45.98 dB at 4.4 GHz. Moreover, being coated with conductive polymer polypyrrole (PPy) by a simple chemical polymerization method, the SiC_nws-CF/PPy nanocomposites exhibited superior EM absorption abilities with maximum RL value of −50.19 dB at 14.2 GHz and the effective bandwidth of 6.2 GHz. The SiC_nws-CF/PPy nanocomposites in this study are very promising as absorber materials with strong electromagnetic wave absorption performance