Spontaneously Healable Thermoplastic Elastomers Achieved through One-Pot Living Ring-Opening Metathesis Copolymerization of Well-Designed Bulky Monomers.

We report here a series of novel spontaneously healable thermoplastic elastomers (TPEs) with a combination of improved mechanical and good autonomic self-healing performances. Hard-soft diblock and hard-soft-hard triblock copolymers with poly[exo-1,4,4a,9,9a,10-hexahydro-9,10(1',2')-benzeno-l,4-methanoanthracene] (PHBM) as the hard block and secondary amide group containing norbornene derivative polymer as the soft block were synthesized via living ring-opening metathesis copolymerization by use of Grubbs third-generation catalyst through sequential monomer addition. The microstructure, mechanical, self-healing, and surface morphologies of the block copolymers were thoroughly studied. Both excellent mechanical performance and self-healing capability were achieved for the block copolymers because of the interplayed physical cross-link of hard block and dynamic interaction formed by soft block in the self-assembled network. Under an optimized hard block (PHBM) weight ratio of 5%, a significant recovery of tensile strength (up to 100%) and strain at break (ca. 85%) was achieved at ambient temperature without any treatment even after complete rupture. Moreover, the simple reaction operations and well-designed monomers offer versatility in tuning the architectures and properties of the resulting block copolymers.

[The Molluscicidal Effect of Chlorosalicylicamide Sustained-release Granules on Oncomelania hupensis].

Objective: To evaluate the molluscicidal effect of the chlorosalicylicamide sustained-release granules (LDS-SRG) on Oncomelania hupensis. Methods: Seven effective concentrations or dosages of LDS-SRG, 0.1, 0.2, 0.4, 0.8, 1.6, 3.2 and 6.4 mg/L （for immersion test） or g/m2（for spraying test）, were prepared from the original 5% and 10% concentrations or dosages in the laboratory. In the immersion test, each concentration of LDS-SRG was incubated with 3 packs of snails（30 snails in each pack）, and each pack was taken for snail counting at 24, 48 and 72 h respectively. In the spraying test, each dosage of LDS-SRG was applied to 200 snails, and the snail mortality was calculated in 50 randmoly collected snails on days 3 and 7, and in the whole on day 14 after administration. In the field immersion test, LDS-SRG at concentrations of 0.4, 0.8 and 1.6 g/m3 was incubated with 6 packs of snails （30 snails in each pack）, and each 2 packs were taken at 24, 48, and 72 h to calculate the snail mortality. In the field spraying test, 0.8, 1.6 and 3.2 g/m2 LDS-SRG was sprayed in 3 snail-positive ditches （～100 m2）, and 10 boxes of snails were selected in each ditch on days 3, 7 and 14 to calculate the snail mortality. The 50% wettable powder of niclosamide ethanolamine salt （WPN） with effective concentrations or dosages of 1.0 mg/L （or g/m2 and g/m3） was used as the positive control. Fresh water served as the blank control. Results: In the labratory immersion test using the original concentration of 5%, both 0.1-6.4 mg/L LDS-SRG for 72 h and 1.6-6.4 mg/L LDS-SRG for 48 h caused 100% mortality; and the concentration lethal to 50% （LC50） at 24, 48 and 72 h was 0.70, 0.01 and 0.01 mg/L respectively. When using the original concentration of 10%, both 0.1-6.4 mg/L LDS-SRG for 72 h and 0.2-6.4 mg/L LDS-SRG for 48 h caused 100% mortality; and the LC50 at 24, 48 and 72 h was 0.15, 0.01 and 0.01 mg/L respectively. The labratory spraying test showed that 7-day administration of 1.6 and 6.4 g/m2 LDS-SRG as well as 14-day administration of 3.2 and 6.4 g/m2 LDS-SRG prepared from 5% dosage, resulted in a snail mortality>95%, with the LD50 on days 3, 7 and 14 being 0.06, 0.16, and 0.18 g/m2; 14-day administration of 1.6 g/m2 LDS-SRG as well as 7-day administration of 6.4 g/m2 LDS-SRG prepared from 10% dosage, resulted in a snail mortality>95%, with the LD50 on days 3, 7 and 14 being 3.29, 0.75, and 0.16 g/m2. The mortality by various dosages of LDS-SRG prepared from 5% dosage was significantly higher than that of the control group (P<0.05). In the field immersion test, the snail mortality by 1.6 g/m3 LDS-SRG prepared from 5% and 10% concentrations for 72 h was 96.43% and 98.21% respectively (P>0.05 versus the control group). In the field spraying test, the snail mortality by 3.2 g/m2 LDS-SRG prepared from 5% dosage for 3, 7 and 14 days was 93.99%, 91.18% and 86.48% respectively, and that from 10% dosage was 94.95%, 93.50% and 85.43%, all significantly higher than that of the control group （82.83%, 72.38% and 48.38%）（P<0.05）; the snail mortality by 0.8 g/m2 LDS-SRG prepared from 5% dosage for 14 days（66.51%） and that by 1.6 g/m2 LDS-SRG prepared from 5% dosage for 3 days（84.61%） were both significantly higher than that by 10% LDS-SRG（20.13% and 43.06%） （P<0.05）. Conclusion: The 5% and 10% LDS-SRG used separately in the immersion test and the spraying test both meet the requirements of the national standard of Efficacy Test Methods and Evaluation of Molluscicide for Pesticide Registration.

Antigenic and genetic variation in the hemagglutinins of H1N1 and H3N2 human influenza a viruses in the Shanghai area from 2005 to 2008.

Continued rapid evolution of the influenza A virus is responsible for annual epidemics and occasional pandemics in the Shanghai area. In the present study, the representative strains of A/H1N1 and A/H3N2 influenza viruses isolated in the Shanghai area from 2005 to 2008 were antigenically and genetically characterized. The antigenic cartography method was carried out to visualize the hemagglutination-inhibition data. Antigenic differences were detected between circulating A/H1N1 strains isolated from 2005 to 2006 and the epidemic A/H1N1 strains isolated in 2008, which were found to be associated with the amino acid substitution K140E in HA1. The present vaccine strain A/Brisbane/59/2007 is considered to be capable of providing sufficient immunity against most of the circulating A/H1N1 viruses isolated in 2008 from the Shanghai population. The study showed that there were significant antigenic differences between the epidemic A/H3N2 strains isolated in 2007 and 2008, suggesting that antigenic drift had occurred in the A/H3N2 strains isolated in 2008. The P194L mutation was thought to be responsible for the antigenic evolution of influenza A/H3N2 viruses isolated from Shanghai in 2008. Evidence of antigenic drift suggests that the influenza A/H3N2 vaccine component needs to be updated.

[Study on evolutionary origin of influenza A virus (H1N1) based on HA gene].

OBJECTIVE: To determine the evolutionary rate and divergence time of influenza A virus HA gene isolated recently worldwide pandemic and explore the origin and its transmission. METHODS: A total of 344 H1 sequences available in the GenBank (including 248 isolated from human, 84 from swine, 11 from avian, and 1 from ferret) and 7 isolated in Shanghai were collected. The nucleotide substitution rate and time to most recent common ancestor (tMRCA) was calculated using molecular clock theory and Bayesian Skyline Plot (BSP) based on Markov chain Monte Carlo. Then genetic phylogeny was constructed referring to posterior distribution. RESULTS: It was found that H1 sequences in the US from human, swine and avian were clustered significantly with swine H1 ones from Asia phylogenetically (Cluster US). The second cluster (Cluster Eurasian Human) nearly consisted of human H1 sequences isolated in other regions. The third cluster (Cluster Eurasian Animal) consisted of swine and avian H1 sequences from China and Italy respectively. As for all the H1 sequences, the evolutionary rate was of 2.57 x 10(-3) substitutions/site per year averagely (95% Highest Posterior Density: 1.96 x 10(-3) - 3.03 x 10(-3)/site per year). The estimated dates for tMRCA of human H1 in Europe and swine H1 in the mainland of China were the earliest, with the corresponding rates of 6.46 x 10(-3)/site per year and 0.97 x 10(-3)/site per year respectively. The tMRCAs of human and swine H1 sequences from the US were similar, with the rates of 5.86 x 10(-3)/site per year and 5.02 x 10(-3)/site per year. CONCLUSION: The present flu outbreak was possibly induced by long-term circulation of influenza A virus (H1N1) in human population and swine herds in America. There was no evidence proving that influenza virus in China involved in the present outbreak.

[Type and subtype distribution of influenza virus and genetic evolution of hemagglutinin in Shanghai area in duration of 2004 - 2008].

OBJECTIVE: To analyze the type and subtype distribution of influenza virus and the genetic evolution of hemagglutinin (HA) in Shanghai area during 2004 to 2008. METHODS: All 962 throat swabs were collected from influenza-like patients in 5 influenza sentry hospitals and influenza outbreaks. Influenza viruses were isolated in MDCK cell lines, and then viral types and subtypes were identified. The HA of influenza A isolates selected by outbreak or sporadic patients in different areas and epidemic seasons were sequenced and analyzed by phylogenetic trees. RESULTS: A/H3N2, accounting for 54.9% (162/295), was the dominate subtype in recent years, but less popular in the end of 2005 to the middle of 2006 with 0% (0/16)and 23.5% (8/34) of positive specimen, respectively. There were more A/H1N1 isolates in 2005 - 2006 with 21.4% (12/56), 43.8% (7/16) and 76.5% (26/34) of positive specimen, respectively, but declined obviously in 2007 - 2008 accounting for only 0% (0/44) and 5.0% (7/139). Influenza B virus was more popular in 2004 to 2005 with 42.9% (24/56) and 56.2% (9/16), respectively, and not isolated from 2006 to 2007, then increased in 2008 accounting for 34.5% (48/139). Phylogenetic tree of HA showed that A/H1N1 isolates in the same year clustered from 2005 to 2008, and most A/H3N2 isolated were homologous in the same year during 2004 - 2008 while some were inserted to the clusters of near years and more distinguished sequences appeared. A/H1N1 and A/H3N2 isolates were all similar to the vaccine strains recommended by WHO. CONCLUSION: The distribution of influenza type and subtype kept on changing each year, but A/H3N2 dominated in most years. A/H1N1 and A/H3N2 in the same year clustered, but some A/H3N2 of near years were and evolved faster with more distinguished strains appeared in same interval. Generally, HA of influenza A isolates in Shanghai during 2004 to 2008 were similar to the WHO reference strains.