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FRP (fiber-reinforced composite) is generally regarded as the repair and enhancement material for existing concrete structures in extreme service environments such as high temperatures or fire exposure. In order to reveal the effect of high temperatures (i.e., thermal load) on the interfacial debonding behavior of a FRP-strengthened concrete beam, the novel closed-form analytical model was established and validated while considering the interfacial bond-slip constitutive. Based on the analytical model, solutions to the distributions of interfacial slip, interfacial shear stress, and debonding load were derived. Moreover, the effects of temperature variations and the FRP's bonded thickness and length on interfacial bond behavior were also evaluated. The results indicated that the increase in temperature variations accelerated the development trends of interfacial slip and shear stress, where the affected range was mainly concentrated in the bonded plate end. The relationship between temperature variations and debonding loads presented a changing linear trend, and a prediction model for the debonding load was also proposed. Meanwhile, the increase in the FRP's bonded thickness decreased the bond performance and accelerated the degradation trend of the debonding load. However, the increase in FRP's bonded length improved the bearing capacity of the FRP-strengthened concrete beam. This paper provides meaningful guidelines for the sustainable design and construction of FRP-strengthened concrete structures in high-temperature environments. [ABSTRACT FROM AUTHOR]

Duck hepatitis virus 1 (DHV-1) is a major threat to the global poultry industry, causing significant economic losses due to high mortality rates in young ducklings. To better understand the evolution and host adaptation strategies of DHV-1, we conducted a comprehensive codon usage analysis of DHV-1 genomes. Our phylogenetic analysis revealed three well-supported DHV-1 phylogroups (Ia, Ib, and II) with distinct genetic diversity patterns. Comparative analyses of the codon usage bias and dinucleotide abundance uncovered a strong preference for A/U-ended codons and a biased pattern of dinucleotide usage in the DHV-1 genome, with CG dinucleotides being extremely underrepresented. Effective number of codons (ENC) analysis indicated a low codon usage bias in the DHV-1 ORF sequences, suggesting adaptation to host codon usage preferences. PR2 bias, ENC plot, and neutrality analyses revealed that both mutation pressure and natural selection influence the codon usage patterns of DHV-1. Notably, the three DHV-1 phylogroups exhibited distinct evolutionary trends, with phylogroups Ia and Ib showing evidence of neutral evolution accompanied by selective pressure, while the phylogroup II evolution was primarily driven by random genetic drift. Comparative analysis of the codon usage indices (CAI, RCDI, and SiD) among the phylogroups highlighted significant differences between subgroups Ia and Ib, suggesting distinct evolutionary pressures or adaptations influencing their codon usage. These findings contribute to our understanding of DHV-1 evolution and host adaptation, with potential implications for the development of effective control measures and vaccines. [ABSTRACT FROM AUTHOR]

This paper applies the Generalized Supremum Augmented Dickey–Fuller (GSADF) approach to highlight the multiple exchange rate bubbles, and detect the interaction between Renminbi (RMB) and Hong Kong dollar (HKD) by logistic regression. The results illustrate that (I) there exists multiple bubbles in the RMB and HKD, and both shows the short‐term period bubbles in the nominal exchange rates whereas performing the long‐term period bubbles in the real exchange rates; (II) the exchange rate bubbles mainly existed during the financial crisis. The RMB bubbles occurred more in domestic financial crisis, while the HKD bubbles occurred in both domestic and international financial crisis; (III) there are interactions between bubbles in the RMB and HKD. Specifically, the bubbles in the nominal exchange rates of the RMB and HKD are reinforcing each other while the bubbles in the real exchange rates markets are mutually hedging; the nominal and real exchange rate market are mutually reinforcing regardless of the RMB or HKD. Furthermore, the strength of interactions between the RMB and HKD shows that the price of the HKD is more stable than that of the RMB. [ABSTRACT FROM AUTHOR]

Boehmeria nivea (Linn.) Gaudich of the Urticaceae family is a perennial ratoon herbal plant, the root of which is used in traditional Chinese medicine and possesses a variety of pharmacological properties. The 20% ethanol Boehmeria nivea root extract was shown to exert an anti-hepatitis B virus (HBV) effect in vitro and in vivo ; however, whether the Boehmeria nivea leaf (BNL) extract possesses similar properties has not been determined. In this study, we aimed to investigate the anti-HBV effects of the BNL extract in HepG2.2.15 cells transfected with human HBV DNA. Our results demonstrated that the secretion of HBsAg and HBeAg was reduced in HepG2.2.15 cells treated with the BNL extract, without any recorded cytotoxic effects. In addition, the chloroform fraction (CF) and ethyl acetate fraction (EAF) of BNL were shown to be more potent compared to the other fractions: CF (100 mg/l) inhibited the secretion of HBsAg by 94.00±1.78% [inhibitory concentration 50 (IC 50 ) = 20.92 mg/l] and that of HBeAg by 100.19±0.35% (IC 50 =19.67 mg/l) after 9 days of treatment. Similarly, EAF (200 mg/l) inhibited the secretion of HBsAg by 89.95±2.26% (IC 50 =39.90 mg/l) and that of HBeAg by 98.90±1.42% (IC 50 =36.45 mg/l). Furthermore, we observed that the content of HBV DNA in the medium secreted by the HepG2.2.15 cells was significantly decreased under CF (100 mg/l) or EAF (200 mg/l) treatment. Thus, we concluded that the BNL extracts exhibited anti-HBV activity, with CF and EAF being the most potent among the fractions.

The present study aims to clarify the inhibitive effect of the compounds from Rheum palmatum L. on the SARS-3CL protease. The SARS-CoV 3CL gene was amplified from RNA of the SARS virus by PCR. The SARS-CoV 3CL protease was purified from a colon bacillus recombinant. Drugs and 3CL protease were incubated together. The inhibition rate and IC(50) were calculated based on absorbance. Components from the Rheum palmatum L. had a high level of anti-SARS-CoV 3CL protease activity. The IC(50) was 13.76 +/- 0.03 microg/mL and the inhibition rate was up to 96%. In conclusion, extracts from Rheum palmatum L. have a high level of inhibitory activity against 3CL protease, suggesting that extracts from Rheum palmatum L. may represent a potential therapeutic for SARS.

To do investigation of flavones from the leaves of Cyclocarya paliums (Batal.) Iljinsk. The pure products were isolated by column chromatography of silica gel, thin layer chromatography of silica gel and column chromatography of Sephadex LH-20, their chemical structures were elucidated by NMR, IR and UV spectroscopic evidence. Four flavones were isolated from the leaves of Cyclocarya paliums. They are quercetin (I), kaempferol (II), kaempferol-7-O-alpha-L-rhamnopyranosyl (III) ,and kaempferol-4'-methoxyl-7-O-beta-D-mancopyranosyl (IV). Compounds III and IV are obtained for the first time from this plants.