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The novel coronavirus (2019-nCoV) is spreading very fast in Hubei Province of China. As of February 14, 2020, 51,986 confirmed cases (including laboratory-confirmed cases and clinically-confirmed cases) were reported in Hubei Province, and 1,318 of them died. Respiratory droplets and contact transmission are considered to be the most important routes of transmission of 2019-nCoV, but do not fully account for the occurrence of all coronavirus disease 2019 (COVID-19) cases, previously known as novel coronavirus pneumonia (NCP), and the reasons for the rapid spread of this virus (1).In Biosafety Level 3 (BSL-3) Laboratory of the National Institute for Viral Disease Control and Prevention, Vero cells were used for viral isolation from stool samples of COVID-19 patients sent by Heilongjiang CDC. A 2019-nCoV strain was isolated from a stool specimen of a laboratory-confirmed COVID-19 severe pneumonia case, who experienced onset on January 16, 2020 and was sampled on February 1, 2020. The interval between sampling and onset was 15 days. The full-length genome sequence indicated that the virus had high-nucleotide similarity (99.98%) to that of the first isolated novel coronavirus isolated from Wuhan, China (Figure 1). In the Vero cells, viral particles with typical morphology of a

Polymer-clay nanocomposites of styrene and methyl methacrylate have been prepared by bulk, solution, suspension, and emulsion polymerization as well as by melt blending. Two different organic modifications of montmorillonite have been used: one contains a styryl monomer on the ammonium ion while the other has no double bond. The organic modification as well as the mode of preparation determines if the material will be exfoliated or intercalated. Exfoliation is more likely to occur if the ammonium ion contains a double bond which can participate in the polymerization reaction, but the mere presence of this double bond is not sufficient to always produce an exfoliated system. Solution polymerization always produced intercalated systems. Neither thermogravimetric analysis nor the tensile modulus can be used to evaluate the type of nanocomposite that has been formed.

The molecular epidemiology of CVA16 in China between 1999 and 2008 reflects a pattern of endemic cocirculation of clusters B1a and B1b within subgenotype B1 viruses. The annual evolution rate of CVA16 was estimated as approximately 0.91 ؋ 10 ؊2 substitutions per synonymous nucleotide/year and is slightly lower than that of HEV71.Coxsackievirus A16 (CVA16) and human enterovirus 71 (HEV71) are the two major causative agents of hand, foot, and mouth disease (HFMD) (12,17). In recent years, numerous large outbreaks of HEV71-associated HFMD, which were often accompanied by severe complications, including death, increased research interest in HEV71 strains (1,14,16). In contrast, little interest was paid to CVA16 strains because CVA16-associated HFMD was usually mild and benign (2, 12). Although CVA16 is genetically most closely related to HEV71, the genetic diversity and molecular evolution of CVA16, unlike those of HEV71, have not been fully described (5,7,12,13). Cocirculation of CVA16 and HEV71 has been proven to have contributed to the serious outbreaks of HFMD that have occurred in China since 2007 (17); therefore, the genetic variability and the evolution of CVA16 were determined in this study.The 42 CVA16 strains evaluated in this study were isolated from HFMD patients from different geographical locations in the Shandong, Gansu, Inner Mongolia, and Qinghai provinces of China between 2007 and 2008 (see supplemental data). To investigate the molecular epidemiology of CVA16 in mainland China, 24 additional Chinese CVA16 sequences found in Beijing and Guangdong provinces between 1999 and 2005 and 35 international CVA16 sequences (obtained from the GenBank database) were also analyzed.The complete VP1/capsid sequences of the CVA16 strains were obtained as previously described, using in-house primers that flanked the VP1 region (13, 17): CVA16-VP1-S, 5Ј-ATTGGTG CTCCCACTACAGC-3Ј (nucleotides 2335 to 2354, relative to strain CVA16/G-10), and CVA16-VP1-A, 5Ј-GCTGTCCTCCC ACACAAGAT-3Ј (nucleotides 3426 to 3445, relative to strain CVA16/G-10).A total of 66 Chinese CVA16 sequences were divided into three lineages on the basis of phylogenetic analysis (Fig. 1). A 6.5 to 8.1% nucleotide divergence was found among these three lineages, suggesting that the CVA16-associated HFMD outbreaks in China were a result of the coincident circulation of three genetically distinct viruses.To determine the molecular epidemiology of Chinese CVA16 strains associated with HFMD epidemics, a phylogenetic dendrogram was constructed with 21 Chinese CVA16 sequences (randomly selected on the basis of their genetic relationships) that circulated during the period 1999-2008 in addition to the 35 international CVA16 sequences that represented two known genotypes (A and B) (13) (Fig. 2).As in a previous study (13), all CVA16 strains could be grouped into genotypes A and B. The prototype G-10 strain differed from the other strains by 27.5 to 30.2% and clustered separately from all other CVA16 strains, including Chinese CVA16 strains, which clearly belo...

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