Preparation of polyethyleneimine-modified chitosan/Ce-UIO-66 composite hydrogel for the adsorption of methyl orange.

In this work, a polyethyleneimine-modified chitosan/Ce-UIO-66 composite hydrogel (PEI-CS/Ce-UIO-66) was prepared using the ex-situ blend method. The synthesized composite hydrogel was characterized by SEM, EDS, XRD, FTIR, BET, XPS, and TG techniques, while the zeta potential was recorded for sample analysis. The adsorbent performance was studied by conducting adsorption experiments using methyl orange (MO), which showed that PEI-CS/Ce-UIO-66 exhibited excellent MO adsorption properties (900.5 ± 19.09 mg/g). The adsorption kinetics of PEI-CS/Ce-UIO-66 could be explained by the pseudo-second-order kinetic model, and its isothermal adsorption followed the Langmuir model. Thermodynamics showed that the adsorption was spontaneous and exothermic at low temperatures. MO could interact with PEI-CS/Ce-UIO-66 via electrostatic interaction, π-π stacking, and hydrogen bonding. The results indicated that the PEI-CS/Ce-UIO-66 composite hydrogel could potentially be used for the adsorption of anionic dyes.

Genotype distribution and evolutionary analysis of rotavirus associated with acute diarrhea outpatients in Hubei, China, 2013-2016.

Group A human rotaviruses (RVAs) annually cause the deaths of 215,000 infants and young children. To understand the epidemiological characteristics and genetic evolution of RVAs, we performed sentinel surveillance on RVA prevalence in a rotavirus-surveillance network in Hubei, China. From 2013 to 2016, a total of 2007 fecal samples from hospital outpatients with acute gastroenteritis were collected from four cities of Hubei Province. Of the 2007 samples, 153 (7.62%) were identified positive for RVA by real-time RT-PCR. RVA infection in Hubei mainly occurred in autumn and winter. The highest detection rate of RVA infection was in 1-2 years old of outpatients (16.97%). No significant difference of RVA positive rate was observed between females and males. We performed a phylogenetic analysis of the G/P genotypes based on the partial VP7/VP4 gene sequences of RVAs. G9P[8] was the most predominant strain in all four years but the prevalence of G2P[4] genotype increased rapidly since 2014. We reconstructed the evolutionary time scale of RVAs in Hubei, and found that the evolutionary rates of the G9, G2, P[8], and P[4] genotypes of RVA were 1.069 â€‹× â€‹10-3, 1.029 â€‹× â€‹10-3, 1.283 â€‹× â€‹10-3 and 1.172 â€‹× â€‹10-3 nucleotide substitutions/site/year, respectively. Importantly, using a molecular clock model, we showed that most G9, G2, P[8], and P[4] genotype strains dated from the recent ancestor in 2005, 2005, 1993, and 2013, respectively. The finding of the distribution of RVAs in infants and young children in Hubei Province will contribute to the understanding of the epidemiological characteristics and genetic evolution of RVAs in China.

Preparation and application of polyethyleneimine-modified corncob magnetic gel for removal of Pb(ii) and Cu(ii) ions from aqueous solution.

As a biomass resource, corncob is a kind of agricultural by-product with wide sources and low cost. Because its composition contains a large number of functional polymers such as cellulose, chitosan, and semi chitosan, corncob can be chemically modified to prepare a variety of adsorption materials. In this study, a magnetic gel material (PEI-CC@Fe3O4) consisting of corncob modified by glutaraldehyde-crosslinked polyethyleneimine (PEI) was successfully prepared and applied to the adsorption of heavy metal ions in aqueous solutions. The structure, thermal stability, and adsorption of heavy metal ions of the magnetic gel material (PEI-CC@Fe3O4) were characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction phase analysis (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). The results showed that PEI was crosslinked to the corncob through Aldol reaction and Schiff-base reaction. The heavy metal ion adsorption experiment showed that the PEI-CC@Fe3O4 had better adsorption toward divalent copper ions and divalent lead ions at 303 K, and the maximum adsorption capacities reached 459.4 mg g-1 and 290.8 mg g-1, respectively. Moreover, the study of isothermal adsorption and adsorption kinetics shows that the adsorption process is pseudo-second-order kinetics model adsorption, which belongs to Langmuir isothermal adsorption. Such excellent adsorption performance will contribute to the application of corncob biomass materials in industrial polluted wastewater.

An Outbreak of Gastroenteritis Associated with GII.17 Norovirus-Contaminated Secondary Water Supply System in Wuhan, China, 2017.

A gastroenteritis outbreak occurred in a university in May, 2017, Wuhan, China. The epidemiological survey and pathogen analysis were conducted to identify the pathogen and control this outbreak. Feces or anal swabs from individuals, water, and swabs taken from tap surfaces of the secondary water supply system (SWSS) and foods were collected for the detection of viruses and pathogenic enteric bacteria by real-time RT-PCR and culture, respectively. Nucleotide sequences were determined by RT-PCR and direct sequencing. Genotyping, phylogenetic, and recombination analyses were conducted by a web-based genotyping tool, MEGA, and RDP4 programs, respectively. Of 144 individuals enrolled, 75 met the case definitions. The epidemic curve showed one peak of incidence suggesting the most probable spread of a single common source. In total, 33 specimens were collected before disinfection of the SWSS. Of these, norovirus was detected and identified as GII.P17-GII.17 with 100% nucleotide sequence identity among the strains detected in ten students (10/14), a maintenance worker (1/2) dealing with the SWSS, four water samples (4/8), and two swabs taken from tap surfaces (2/3). Pathogens including Vibrio cholerae, Salmonella, Shigella, Vibrio parahaemolyticus, Bacillus cereus, enteropathogenic Escherichia coli, rotavirus, astrovirus, and sapovirus were negative. The GII.17 strains in this outbreak clustered closely in the same branch of the phylogenetic tree, and slightly apart from the strains of other cities in China, neighboring countries and regions, European and American countries. This gastroenteritis outbreak was deduced to be attributed to GII.P17-GII.17 norovirus contamination of the SWSS.

[Epidemiologic analysis on severe fever with thrombocytopenia syndrome in Hubei province, 2010].

OBJECTIVE: To identify the epidemic characteristics and risk factors of an emerging infectious disease-severe fever with thrombocytopenia syndrome (SFTS) in Hubei province. METHODS: Active surveillance program on SFTS was set up in monitoring sites-hospitals, at the township level or above, in Suizhou, Huanggang and Wuhan from January to December, 2010. Specific surveillance program on SFTS was launched across the province in hospitals above the county level. Cases that matched the definition of surveillance case were identified and reported to Centers for Disease Control and Prevention (CDCs). Cases were interviewed and their blood samples collected and detected using PCR and virus isolation. We also conducted serum antibody surveys among healthy population and livestock and surveillance on vector ticks in those high-epidemic areas. RESULTS: 188 cases that matched the definition of surveillance case and 21 deaths were reported in 11 cities, 32 countries and 100 towns in 2010, with an incidence rate of 0.33/10(6). The fatality rate was 11.2%. Data showed that the patients were from hilly areas at the altitude elevated between 28-940 meters. The epidemic period was between April and December with the peak from May to September. The youngest case was an 11-year old, while the eldest was 81 with median age as 56-year old. 95.3% of the patients were farmers. All Patients did not have the history of traveling, two weeks before the onset of SFTS. 93.6% of the patients engaged in different kind of work which was associated with agriculture. 52.8% of the patients had been exposed to ticks. 22.0% of the patients had been bitten by ticks. Skin injury was found in 64.2% of the patients. Samples from 129 cases (68.6%) were collected and detected, with 67.4% of them (87 cases) showed positive by Real time-PCR for SFTS virus. An elevation in antibody titer by a factor of four or evidence of sero-conversion was observed in 11 patients; SFTS virus was isolated from 2 patients. The total antibody positive rates were 3.8%, 55.0% (6/11), 36.7% (2/3) and 80.0% (4/5) respectively in healthy population, dogs, sheep and cows. Ticks from grass, cattle and sheep were detected positive by Real time-PCR. CONCLUSION: Most cases of SFTS in Hubei were infected by SFTS virus, and cases of livestock were infected by SFTS virus. Ticks might serve as an important vector. Skin injury, exposure to tick bites seemed to be the risk factors.

Genetic characteristics of 2009 pandemic H1N1 influenza a viruses isolated from Mainland China.

A total of 100 H1N1 flu real-time-PCR positive throat swabs collected from fever patients in Zhejiang, Hubei and Guangdong between June and November 2009, were provided by local CDC laboratories. After MDCK cell culture, 57 Influenza A Pandemic (H1N1) viruses were isolated and submitted for whole genome sequencing. A total of 39 HA sequences, 52 NA sequences, 36 PB2 sequences, 31 PB1 sequences, 40 PA sequences, 48 NP sequences, 51 MP sequences and 36 NS sequences were obtained, including 20 whole genome sequences. Sequence comparison revealed they shared a high degree of homology (96%-99%) with known epidemic strains (A/California/04/2009(H1N1). Phylogenetic analysis showed that although the sequences were highly conserved, they clustered into a small number of groups with only a few distinct strains. Site analysis revealed three substitutions at loop 220 (221-228) of the HA receptor binding site in the 39 HA sequences: A/Hubei/86/2009 PKVRDQEG → PKVRDQEA, A/Zhejiang/08/2009 PKVRDQEG → PKVRDQER, A/Hubei/75/2009 PKVRDQEG → PKVRDQGG, the A/Hubei/75/2009 was isolated from an acute case, while the other two were from patients with mild symptoms. Other key sites such as 119, 274, 292 and 294 amino acids of NA protein, 627 of PB2 protein were conserved. Meanwhile, all the M2 protein sequences possessed the Ser32Asn mutation, suggesting that these viruses were resistant to adamantanes. Comparison of these sequences with other H1N1 viruses collected from the NCBI database provides insight into H1N1 transmission and circulation patterns.