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Objective To explore the protective mechanism of geraninn on acute lung injury (ALI) induced by lipopolysaccharide (LPS) in mice. Methods Forty-eight BALB/c mice (female, 4 weeks old, 18~22 g) were randomly divided into 6 groups (n=8): the blank group(control group), the LPS group, the dexamethasone group (Dex group, 2mg/kg), the geraninn low dose group (LD group, 10 mg/kg), the geraninn medium dose group (MD gruop, 20 mg/kg) and the geraninn high dose group (HD group, 40 mg/kg). The mice in blank group and LPS group were fed with normal saline, the mice in the Dex group were fed with dexamethasone and the mice in geraniin groups were given corresponding dose of drugs. Normal saline and all tested drugs were given once a day for 3 d. In 1 h later after the last administration, the acute lung injury model was established by using intranasal drip of LPS (4 mg/kg) in all groups except the blank group. In 6 h after modeling, the wet-to-dry (W/D) weight ratio of the lung tissues of mice in each group was collected. The pathological changes of lung tissue were observed by HE staining, and the number of inflammatory cells in broncho alveolar lavage fluid (BALF) and blood was measured; The levels of interleukin-6 (IL-6), interleukin-1β and tumor necrosis factor α (TNF-α) in plasma and BALF were detected by ELISA. The amount of p-NF-κBp65 was detected by immunohistochemical method. Results Compared with the blank group, the alveolar structure in LPS group was destroyed, inflammatory cell infiltrated, and the contents of IL-6, IL-1β and TNF-α in serum and BALF in the LPS group increased; The W/D weight ratio of the lung tissues, the number of macrophages and neutrophils in BALF and serum, the relative expression of p-NF-κBp65 in lung tissue also increased(P < 0.01). Compared with the LPS group, pathological state of the lung tissues improved obviously among the groups (except the blank group); The contents of IL-6, IL-1β, TNF-α in the serum and BALF, the W/D ratio of the lung tissues, the numbers of macrophages and neutrophils in BALF and the relative expression of p-NF-κBp65 of the lung tissue decreased evidently(P < 0.05). Conclusion Geraninn has a protective effect on acute lung injury in mice, and its mechanism may be related to the effect that geraninn leads to repression of p-NF-κB p65 and reduces the expression of inflammatory factors (IL-6, IL-1β and TNF-α).

On the basis of the International Reference Ionosphere (IRI) model, the reconstruction of the ionospheric model is realised by optimising the key parameters of the sunspots with the GNSS data integrated. The accuracy of the reconstruction model is verified through Global Navigation Satellite System (GNSS) data. Results show that the total electron content (TEC) calculated by the reconstructed model is significantly improved, and its accuracy is higher than that provided by the IRI model when elevation angle is above 5°. It suggests that the method given in this paper has strong scalability. [ABSTRACT FROM AUTHOR]

The broadcast automatic dependent surveillance (ADS-B) system is a new-generation air traffic control system designed to avoid the waste of resources in secondary radars. The establishment of the spaceborne ADS-B system provides a broad prospect for ionospheric tomography. In this paper, the external observation information of the ionosphere is obtained by measuring the Faraday rotation angle, that is, the total electron content (TEC). Tomography research can be carried out all over the world to conduct large-scale ionospheric electron density research. The experiment selected two different regions and had a time resolution of two hours, a height resolution of 200 km, a latitude resolution of 2°, and a longitude resolution of 5°. Based on the simulated spaceborne ADS-B signal to invert the regional ionospheric electron density, the latitude, longitude, and height distributions of inversion result are basically consistent with those of the actual ionospheric electron density. [ABSTRACT FROM AUTHOR]

Accurate prediction of rain attenuation is critical for the design of terrestrial line‐of‐sight link systems above 5 GHz, particularly for millimetre‐wave frequency. Anomalous behaviour in the adjustment factor in existing rain attenuation prediction models is significantly greater than 1 at short distances and has been reported. To solve this problem and improve the accuracy, a rain attenuation prediction model for terrestrial line‐of‐sight links is proposed. The total rain attenuation described in the model accounts for the contributions of wet antenna attenuation and path rain attenuation. In addition, a rainfall rate adjustment factor is proposed. The proposed model has a root‐mean‐square error of 21.54% in prediction, which is an improvement compared to other existing models. Because the rainfall rate adjustment factor used in the model approaches 1 at short distances, the model can be applied to rain attenuation prediction for short‐distance links. The results will assist designers to design link margins more accurately. [ABSTRACT FROM AUTHOR]