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Based on detailed long-term data of wind regimes collected from typical ventilation sites along the railways in the Gobi area of Xinjiang, this study systematically analyzes the characteristics of the disastrous wind-sand environment along the railways by combining gradient sand sampling data collected by a wind-drift sand monitoring system and site survey data. Wind direction and speed rose diagrams revealed the prevailing wind direction in each wind area along the railways, and this is the wind direction from which the maximum frequency of sandstorms occurred. Drift potential characteristic parameters ( RDP , RDD ) and the direction variability ( RDP / DP ) showed that each wind area along the Gobi railway featured a long wind period, with strong power in a single wind direction. The special geological environment of the Gobi determines the wind-drift sand that features gravel of large grain size and unsaturation, which are different from the wind-drift sand in deserts. With increasing wind velocity, the density of the wind-drift sand increased steadily; however, at a certain critical value, the density surged. This study on the wind-sand environment of the Gobi has significance for railway safety. The critical value of wind velocity corresponded to an abrupt increase in the wind-drift sand density and should be taken into account during the planning process of railway safety passage, since this will lead to a decrease in frontal visual distance, and an associated decrease in safety. Additionally, the specific features of wind-drift sand activities, such as the abruptness and higher than usual sand height, should be considered during the process of designing sand-damage-control engineering measures. [ABSTRACT FROM AUTHOR]

The Qinghai-Tibet railway, the highest railway in terms of elevation, was built under the harshest of weather conditions in the world. A new technique, called the ventiduct embankment, was used for the first time in railway construction in the Qinghai-Tibet permafrost region of China to overcome the specific difficulties of the permafrost plateau. To evaluate its effectiveness, several full-scale test embankments were constructed at a representative field site, the Qingshuihe experimental section. The effectiveness of the ventiduct embankment structure has been verified by comparing it with the performance of the nearby control embankment in terms of permafrost table, settlement, and thaw depth. These observations are presented in this paper. The ventiduct embankment structure based on this study has been adopted in Qinghai-Tibet permafrost railway construction. [ABSTRACT FROM AUTHOR]

Abstract: Four new triterpenoids, sweriyunnangenin A (1), sweriyunnanosides A (2), B (3) and C (4), along with nineteen known compounds (5–23) were isolated from Swertia yunnanensis. Based on extensive spectroscopic analyses (1D- and 2D-NMR, HRESIMS, UV, IR, [α]D), the structures of sweriyunnangenin A (1), sweriyunnanosides A (2), B (3) and C (4) were elucidated as taraxer-14-ene-3α,6β-diol, oleanolic acid 28-O-β-d-glucopyranosyl-(1→2)-O-β-d-glucopyranoside, 2α,3β-di-hydroxyolean-12-en-28-oic acid 28-O-β-d-glucopyranosyl(1→6)-β-d-glucopyranosyl (1→6)-β-d-glucopyranosyl(1→2)-β-d-glucopyranoside and hederagenin 28-O-β-d-glucopyranosyl(1→6)-β-d-glucopyranosyl(1→6)-β-d-glucopyranosyl(1→2)-β-d-glucopyranoside, respectively. Twenty-two compounds were evaluated for their anti-HBV activities on the HepG 2.2.15 cell line in vitro, of which nine compounds showed potent anti-HBV activities. Compounds 1, 5–6, 14–16 and 19 showed activities against the secretion of HBsAg (IC50 values from 0.10 to 1.76mM) and HBeAg (IC50 values from 0.04 to 1.41mM), and compounds 11 and 13–16 exhibited significant inhibition on HBV DNA replication (IC50 values from 0.01 to 0.09mM). [Copyright &y& Elsevier]

Abstract: Swerpunilactones A (1) and B (2), two novel xanthone and secoiridoid heterodimers, together with their presumed biosynthetic precursors (±)-gentiolactone (3), bellidifolin (4), and norbellidifolin (5), were isolated from the whole plants of Swertia species. A plausible biogenetic pathway for swerpunilactones A and B was proposed. In vitro anti-hepatitis B virus assay on the Hep G 2.2.15 cell line showed that both compounds 1 and 2 exhibited activities against the secretion of HBsAg (IC50 =0.25 and 0.29mM), HBeAg (IC50 =0.86 and 0.31mM), and HBV DNA replication (IC50 =0.18 and 0.19mM). [Copyright &y& Elsevier]

Objective: This study was designed to compare the clinical efficacy and safety of transcatheter arterial chemoembolization (TACE) combined with apatinib and TACE alone in the treatment of intermediate and advanced hepatocellular carcinoma (HCC). Methods: From March 2015 to August 2015, a total of 44 patients with moderate and advanced HCC, who were admitted in the Navy General Hospital of China, were included into this study. These patients were randomly divided into 2 groups: group A and group B. Patients in group A underwent TACE alone, while patients in group B underwent the combined treatment of TACE with apatinib. Differences in preoperative general data between these 2 groups were not statistically significant (P> 0.05). All patients were followed up for 12–18 months. Changes in α-fetal protein (AFP) at 3 months after treatment and the objective response rate (ORR) at 3, 6, 9 and 12 months after treatment were compared between these 2 groups. Furthermore, progression-free survival (PFS) and the incidence of adverse reactions were also compared between these 2 groups. Results: AFP levels in groups A and B significantly decreased after 3 months of treatment, compared with the levels before treatment, and the differences were statistically significant (P< 0.05). However, at 3 months after treatment, the difference between these 2 groups was not statistically significant (P> 0.05). ORR at 3, 6, 9 and 12 months after treatment was 36.36%, 27.27%, 13.64% and 9.09%, respectively, in group A; and 60%, 50%, 45% and 35%, respectively, in group B. At 3 and 6 months after treatment, the differences between these 2 groups were not statistically significant (P> 0.05); while at 9 and 12 months after treatment, the differences between these 2 groups were statistically significant (P< 0.05). The median PFS was 6.0 months in group A and 12.5 months in group B, and the difference was statistically significant (P< 0.05). The incidences of complications were related to oral apatinib, such as hypertension, hand-foot syndrome and proteinuria, were higher in group B than in group A, and the differences were statistically significant (P< 0.05). These symptoms all alleviated after symptomatic treatments. Conclusions: For intermediate and advanced HCC, the long-term curative effect of TACE combined with apatinib is better than that of TACE alone. The former can obviously prolong the PFS of patients and has a confirmed safety. [ABSTRACT FROM PUBLISHER]

Wind-shield walls decrease the velocity of wind-drift sand flow in transit. This results in sand accumulating in the wind-shadow zone of both windshield wall and track line, causing severe sand sediment hazard. This study reveals the characteristics of sand accumulation and the laws of wind-blown sand removal in the wind-shadow areas of three different types of windshield walls, utilizing three-dimensional numerical simulations and wind tunnel experiments and on-site sand sediment tests. The results revealed the formation of apparent vortex and acceleration zones on the leeward side of solid windshield walls. For uniform openings, the vortex area moved back and narrowed. When bottom-opening windshield walls were adopted, the track-supporting layer at the step became a conflux acceleration zone, forming a low velocity vortex zone near the track line. At high wind speeds, windshield walls with bottom-openings achieved improved sand dredging. Considering hydrodynamic mechanisms, the flow field structure on the leeward side of different types of windshield structures is a result of convergence and diffusion of fluids caused by an obstacle. This convergence and diffusion effect of air fluid is more apparent at high wind velocities, but not obvious at low wind velocities. [ABSTRACT FROM AUTHOR]