Stress and deformation analysis of the steel pipe arch integral lifting construction process of a continuous beam arch bridge.

The Changjinghuang Railway Xinjiang Xizhi Bridge is a (90 + 180 + 90) m continuous beam arch bridge, and the arch rib steel pipe installation adopts "short bracket assembly and overall lifting method". In order to ensure the accuracy of closure, the stress and deformation of the arch rib and bracket must be strictly controlled. Midas Civil is used to establish the finite element model to simulate the overall lifting construction process of the arch rib. Based on the model, the stress and deformation of the arch rib and the supports are analyzed, and the determination method of the horizontal cable force under temperature variations is proposed. The results show that the stress and deformation of the arch rib and bracket meet the requirements. Considering the variation of temperature, the tension force of the horizontal cables is taken as 200 t. The construction plan proposed under the guidance of numerical calculation results has been proven by practical engineering to meet the requirement of closure accuracy, which can be used as a reference for similar projects.

Calcium peroxide alleviates the waterlogging stress of rapeseed by improving root growth status in a rice-rape rotation field.

Waterlogging stress has a negative influence on agricultural production, particularly for rapeseed yield in a rice-rape rotation field. To alleviate the profound impacts of waterlogging stress on rapeseed production, a new fertilization with calcium peroxide (CaO2) was proposed. In this field experiment, with the conventional rape (Brassica napus L.) variety fengyou958 (FY958) and early maturing rape variety xiangyou420 (XY420) as materials, waterlogging was imposed from the bud to flowering stage, and three supplies of CaO2 (0, C1 for the 594 kg hm-2 and C2 for the 864 kg hm-2) were added as basal fertilizer. The results showed that CaO2 significantly reduced the accumulation of fermentation products in roots and alleviated the peroxidation of leaves. The reduced waterlogging stress promoted the root vigor and agronomic characters, such as branches, plant height and stem diameter, accelerated dry matter and nutrients accumulation, and resulting in 22.7% (C1) to 232.8% (C2) higher grain yields in XY420, and 112.4% (C1) to 291.8% (C2) higher grain yields in FY958, respectively. In conclusion, 594 kg hm-2 to 864 kg hm-2 CaO2 application restored the growth of waterlogged rapeseed leaves, and reduced the anaerobic intensity of root, which enhanced the resistance of plants to waterlogging, and improved crop productivity. In a certain range, the higher CaO2 application, the more the yield. This study provides a valid method to prevent damage from flooding in crop fields.

Preparation and Properties of Thrombus-Targeted Urokinase/Multi-Walled Carbon Nanotubes (MWCNTs)-Chitosan (CS)-RGD Drug Delivery System.

In order to improve the therapeutic effect, prolong the action time and reduce the side effects of the first generation thrombolytic drug urokinase (UK), a novel UK/multi-walled carbon nanotubes (MWCNTs)-chitosan (CS)-arginine-glycine-aspartic acid (Arg-Gly-Asp) (RGD) drug delivery system was synthesized by chemical bonding/non covalent bond modification/ultrasonic dispersion. The results showed that the diameter of the UK/MWCNTs-CS-RGD drug delivery system was about 30-40 nm, there was a layer of UK was attached to the surface of the tube wall, and the distribution was relatively uniform. The average encapsulation efficiency was 83.10%, and the average drug loading was 12.81%. Interestingly, it also had a certain sustained-release effect, and its release law was best fitted by first-order kinetic equation. Moreover, the accelerated and long-term stability test results show that it had good stability. Compared with free UK, UK/MWCNTs-CS-RGD had thrombolytic effect in vitro. In addition, MTT experiment showed that the prepared MWCNTs-CS-RGD nanomaterials had good biocompatibility. A rabbit model of carotid artery thrombosis was used to conduct targeted thrombolysis experiments in vivo. Compared with free UK, UK/MWCNTs-CS-RGD could be enriched in the thrombosis site to achieve thrombus targeting. UK/MWCNTs-CS-RGD drug delivery system was expected to become an effective thrombolytic drug for targeted therapy of thrombosis.

Preparation and characterization of acetylsalicylic acid/chitosan nanoparticles and its antithrombotic effects.

Chitosan (CS)-acetylsalicylic acid (ASA) nanoparticles, which are well dispersed and stable in aqueous solution, have been prepared by interpolymer complexation of ASA in CS solution. The physicochemical properties of nanoparticles were investigated by using FT-IR, 1H NMR, scanning electron microscope（SEM）, dynamic light scattering, and UV spectrophotometer. It was found that the carboxyl group of the ASA had firmly integrated on the amino group of CS and the ASA-CS nanoparticles were almost spherical in shape with an average diameter of less than (79.3 ± 24.6) nm in high reproducibility and showed high chemical stability against environmental changes. It was also found that the prepared nanoparticles carried a positive charge and showed the size in the range from 700 to 150 nm. The surface structure and zeta potential of nanoparticles can be controlled by different preparation processes. The factor experiment results indicated that the ASA-CS nanoparticles had satisfactory loading capacity (LC) and encapsulation efficiency (EE), 27.27% and 46.88% (data not shown), respectively. The experiments of in vitro ASA release showed that these nanoparticles provided a sustained and pH-dependent drug release manner, and the release behavior was influenced by the pH value of the medium. Preliminary pharmacology experiment exhibited prolonged circulation and higher bioavailability than that of ASA. All the results indicated that ASA/CS nanoparticles may have promising pharmaceutical application, and further pharmacological research is needed to confirm these beneficial effects.

Which neoadjuvant chemotherapy regimen should be recommended for patients with advanced nasopharyngeal carcinoma?: A network meta-analysis.

BACKGROUND: The clinical application has widespread disagreement on the different regimens of neoadjuvant chemotherapy (NCT) in the treatment of locoregionally advanced nasopharyngeal carcinoma (NPC). We conducted a network meta-analysis (NMA) to evaluate the efficacy of the different NCT regimens in the treatment of NPC. METHODS: A systematic literature search was performed using PubMed, Embase, and Cochran Library. Totally, 31 randomized controlled trials (RCTs) (n = 4062) met study selection criteria and were incorporated in this NMA study. RESULTS: Our study showed that certain NCT regimens improved the prognosis of patients, and found out the relative best solution for each endpoint, such as paclitaxel, carboplatin, and gemcitabine for 1-year overall survival (OS) rate, cisplatin, calcium folinate, and 5-fluorouracil for 2-year OS rate, vinorelbine and cisplatin (NP) for 3-year OS rate, cyclophosphamide, cisplatin, and 5-fluorouracil for 5-year OS rate, NP for complete remission rate, cisplatin and gemcitabine for overall remission rate of the primary tumor. In addition, for certain grade 3 and above toxicity, the results of the NMA reflected certain NCT regimens can reduce toxicity of chemoradiotherapy (CRT) to a minimum, such as NP for anemia, mucositis, and thrombocytopenia, paclitaxel, epirubicin, and cisplatin for neutropenia and skin toxicity. CONCLUSION: Our NMA showed that certain cisplatin-based NCT regimens improved the prognosis of patients with NPC and reduced the toxicity of CRT. However, in view of survival rate and response rate, the best NCT regimen is not entirely consistent. Therefore, which NCT regimen will benefit most patients will need further explored.

Development and application of a recombinant M protein-based indirect ELISA for the detection of porcine deltacoronavirus IgG antibodies.

Porcine deltacoronavirus (PDCoV) is a recently identified coronavirus in the genus Deltacoronavirus that can cause enteric disease including diarrhea, vomiting, dehydration and mortality in neonatal piglets. Serological assays to detect anti-PDCoV antibodies are presently limited to certain laboratories and geographic regions. In this study, a recombinant M protein-based indirect enzyme-linked immunosorbent assay (PDCoV-rM ELISA) was developed and utilized to determine the prevalence of anti-PDCoV IgG in Hebei province. The PDCoV-rM ELISA showed no cross-reaction with antisera against transmissible gastroenteritis virus (TGEV), porcine epidemic diarrhea virus (PEDV), porcine rotavirus (PRV), porcine circovirus 2 (PCV2), classical swine fever virus (CSFV) or porcine reproductive and respiratory syndrome virus (PRRSV). The diagnostic sensitivity was 90.6% and the diagnostic specificity was 93.3%. A total of 871 serum samples collected in Hebei from January 2015 to October 2016 were checked for presence of antibodies against PDCoV using the novel PDCoV-rM ELISA. Anti-PDCoV IgG antibodies were detected in 11% (96/871) of the samples and in 25% (10/40) of the investigated farms. The data suggest that PDCoV has a low seroprevalence in pig population in Hebei province, China.

Metabolic discrimination of Swertia mussotii and Swertia chirayita known as "Zangyinchen" in traditional Tibetan medicine by (1)H NMR-based metabolomics.

Swertia mussotii Franch. and Swertia chirayita Buch.-Ham. have been commonly used under the same name "Zangyinchen" for the treatment of liver and gallbladder diseases in traditional Tibetan medicine. Detailed characterization and comparison of the complete set of metabolites of these two species are critical for their objective identification and quality control. In this study, a rapid, simple and comprehensive (1)H NMR-based metabolomics method was first developed to differentiate the two species. A broad range of metabolites, including iridoid glycosides, xanthones, triterpenoids, flavonoids, carbohydrates, and amino acids, were identified. Statistical analysis showed evident differences between the two species, and the major markers responsible for the differences were screened. In addition, quantitative (1)H NMR method (qHNMR) was used for the target analysis of the discriminating metabolites. The results showed that S. mussotii had significantly higher contents of gentiopicrin, isoorientin, glucose, loganic acid, and choline, whereas S. chirayita exhibited higher levels of swertiamarin, oleanolic acid, valine, and fatty acids. These findings indicate that (1)H NMR-based metabolomics is a reliable and effective method for the metabolic profiling and discrimination of the two Swertia species, and can be used to verify the genuine origin of Zangyinchen.

Occurrence of arsenic in core sediments and groundwater in the Chapai-Nawabganj District, northwestern Bangladesh.

Groundwater and core sediments of two boreholes (to a depth of 50m) from the Chapai-Nawabganj area in northwestern Bangladesh were collected for arsenic concentration and geochemical analysis. Groundwater arsenic concentrations in the uppermost aquifer (10-40m of depth) range from 2.8microgL(-1) to 462.3microgL(-1). Groundwater geochemical conditions change from oxidized to successively more reduced, higher As concentration with depth. Higher sediment arsenic levels (55mgkg(-1)) were found within the upper 40m of the drilled core samples. X-ray absorption near-edge structure spectroscopy was employed to elucidate the arsenic speciation of sediments collected from two boreholes. Environmental scanning electron microscopy and transmission X-ray microscopy were used to investigate the characteristics of FeOOH in sediments which adsorb arsenic. In addition, a pH-Eh diagram was drawn using the Geochemist's Workbench (GWB) software to elucidate the arsenic speciation in groundwater. The dominant groundwater type is Ca-HCO(3) with high concentrations of As, Fe and Mn but low levels of NO(3)(-) and SO(4)(2-). Sequential extraction analysis reveals that Mn and Fe hydroxides and organic matter are the major leachable solids carrying As. High levels of arsenic concentration in aquifers are associated with fine-grained sediments. Fluorescent intensities of humic substances indicate that both groundwater and sediments in this arsenic hotspot area contain less organic matter compared to other parts of Bengal basin. Statistical analysis clearly shows that As is closely associated with Fe and Mn in sediments while As is better correlated with Mn in groundwater. These correlations along with results of sequential leaching experiments suggest that reductive dissolution of MnOOH and FeOOH mediated by anaerobic bacteria represents an important mechanism for releasing arsenic into the groundwater.