The 2009 A H1N1 viruses have spread throughout the world, as the viral neuraminidase (NA) is a receptor-destroying enzyme, removing sialic acid from carbohydrate chains attached to NA, and releasing ...the viruses from infected cells. In this study, the NA genes of Guangdong viruses were sequenced, then their B-cell epitopes were predicted, screened and assessed based on immunoinformatics. The antisera were raised in rabbits against five linear synthetic peptides spanning the NA protein of 2009 A H1N1. Five peptides, LR17, SS12, DP9, DS11 and DI14, respectively, are capable of eliciting neutralizing antibodies against 2009 A H1N1 in the in vitro microneutralization assay. DI14 was identified to be particularly potent in eliciting a neutralizing antibody titer comparable to that obtained with a whole virion-immunized serum. Immunization of rabbit with either five peptides triggered a 2009 A H1N1-specific antibody response as high as that obtained with the whole virion as immunogen. Alignment with databases showed that the amino acid residues of five epitope peptides are highly conserved among the NA sequences of 2009 A H1N1 strains isolated from the world. Altogether, these data indicate that LR17, SS12, DP9, DS11 and DI14 represent a promising candidate for an effective synthetic peptide-based vaccine against 2009 A H1N1 viruses.
Influenza surveillance networks in Guangdong were established to investigate the epidemiological characteristics of influenza and influenza epidemics. Influenza activity peaked annually from March to ...July in Guangdong in 1991-2000; influenza H3N2 predominated in the epidemic (7 years of 10); the outbreak of influenza in 1996 was the remarkable result of antigenic drift of H3N2 strain. Ten isolates of H9N2 strains were discovered from human subjects in 1998 and 1999: chicken strains isolated after the Hong Kong fowl influenza outbreak. It was found that there was just one influenza activity season per annum in Guangdong and that the influenza H3N2 subtype still predominates in Guangdong. Further research into the pathogenicity of influenza H9N2 in humans warranted.
Background: Since cases of humans infected with avian influenza A(H5N1) virus were reported in Hong Kong, the world has been surprised. Guangdong Province has a similar climate and geographic ...environment to Hong Kong, and a prosperous poultry market gives rise to the potentiality of an epidemic or outbreak of human infection with A(H5N1) virus. Therefore, a strengthened surveillance of influenza viruses was carried out in eight cities of Guangdong Province during March–October 1998.
Methods: Samples of throat swabs were taken from outpatients with influenza-like illness and inpatients with bronchitis, pneumonia or other infections in the lungs, and of pharynx fluid from chickens in farming markets, and then inoculated into embryonated chicken eggs for isolation of influenza viruses. The hemagglutination (HA)-positive fluid derived from the embryonated eggs was then identified by the hemagglutination inhibition (HAI) test. Sera of the occupational group of raising, selling and slaughtering chickens and the general group were taken and tested for antibody to influenza viruses by HAI.
Results: A total of 8563 specimens of human throat swabs were collected and 242 isolates were identified as flu viruses. Of 242 isolates, 193 were A(H3N2), 4 were A(H1N1), 36 were type B and 9 were A(H9N2). A(H5N1) virus was not found. The predominant strain was A(H3N2), making up 79.8% of the all isolates, followed by type B (14.8%). Of 9 A(H9N2) viruses, 4 were isolated in Shaoguan City and 5 in Shantou City, respectively. The time distribution of influenza viruses isolated was 10 isolates in March, 52 in April, 45 in May, 52 in June, 34 in July, 28 in August, 17 in September and 4 in October. Of 9 A(H9N2) viruses, 2 strains were isolated in July, 6 in August and 1 in September, respectively. HAI titers of H9 antibody were 1:160 in one of nine suspected cases from whom A(H9N2) were isolated. Antibodies to A(H5N1) were not detectable in 1512 sera of occupational group and 885 sera of general individuals.
Conclusions: In the surveillance of influenza, 242 influenza viruses were isolated from 8563 specimens of human throat swabs viruses in Guangdong Province, China 1998. The predominant strain was A(H3N2). Nine strains of A(H9N2) were isolated from human throat swabs.
The abiotic transformation of polycyclic aromatic hydrocarbons (PAHs) is significantly impacted by soil components, especially inorganic redox species like iron oxides. In this study, the catalytic ...activities of three types of iron oxides in PAHs degradation without light irradiation were evaluated using a combination of experimental techniques. The results showed that α-Fe2O3 possessed the highest transformation rate for anthracene (ANT), with a reaction rate constant (Kobs) up to 0.28 d−1, followed by Fe3O4 (Kobs = 0.06 d−1) and α-FeOOH (Kobs = 0.06 d−1). X-ray photoelectron spectroscopy (XPS) characterization suggested that α-Fe2O3 had the highest oxygen vacancy concentration, which was conducive to the adsorption of O2 by α-Fe2O3, providing sufficient adsorbed oxygen species. Oxygen vacancy contributed to the exposure of Fe(III), and accordingly, more active sites were created that were responsible for ANT degradation. According to these results, two possible pathways for the degradation of PAHs on iron oxides can be concluded: (1) direct oxidation by Fe(III) and (2) oxidation by the O2•− generated onto oxygen vacancies. This study provides significant insights into the environmental fate of PAHs on iron oxides, and raises the possibility that iron oxides may be used as catalytic materials in the remediation PAHs-contaminated soil.
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•α-Fe2O3 is highly efficient to transform PAHs without light irradiation.
•Oxygen vacancy concentration affects the PAHs degradation rate.
•Oxygen vacancy contributes to the exposure of Fe(III) and provides active sites.
•Catalytic efficiency is dependent on the synergistic effects of Fe(III) and O vacancies.
Membrane separation is a promising approach for the remediation of oil contamination in water. High-flux separation of membrane relies on the rational design of ultrathin active layer to ...significantly reduce mass transfer distance for achieving high separation flux, while the ultrathin active layer is usually fragile with poor mechanical strength, which has to be supported on a support. Herein, we employed collagen fiber membrane (CFM) as multi-functional support for the in-situ growth of polyacrylonitrile (PAN) layer by electrospinning to prepare the high-performance PAN/CFM composite membrane. Due to the amphiphilic nature and strong capillary effect, CFM played the role as multi-functional support to provide separation effectiveness and boosted separation flux. The PAN/CFM composite membrane enabled ultrahigh separation flux (e.g., 51751.59 L m−2 h−1 bar−1) to a variety of oil-in-water emulsion, which was one order of magnitude higher than that of commercial polyethersulfone membrane and 1.86-fold to that of cellulose acetate membrane. Furthermore, the PAN/CFM composite membrane retained high separation flux (e.g., 11046.97 L m−2 h−1 bar−1) during the 5th separation cycle, providing appreciable anti-fouling capability. Therefore, our findings provided a promising way to effectively resolve the problem of oil contamination in water.
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•Collagen fiber membrane (CFM) played the role as multi-functional support.•CFM was able to provide separation effectiveness and boost separation flux.•A polyacrylonitrile layer in-situ grown on CFM was hydrophilic and underwater superoleophobic.•The composite membrane enabled efficient separation of oil contamination in water.•Ultrahigh separation flux and separation effectiveness were achieved.
Environmentally persistent free radicals (EPFRs) as intermediate products exist widely in the PAHs-contaminated soils, but toxicity assessment associated with EPFRs for terrestrial invertebrates ...remains unclear. Using the model organism Eisenia fetida, we compared the adverse effects among anthracene (ANT), anthraquinone (ANQ), and EPFRs induced by ANT transformation on clay surfaces. Our results showed that EPFRs-exposed earthworms experienced histopathological damage, which was more severe than ANT and ANQ-exposed earthworms. The source of EPFRs damage was associated with the obvious dysbiosis of reactive oxygen species in earthworms. Specifically, EPFRs trigged more severe antioxidant responses and oxidative damages (e.g., membrane lipid and DNA injury) in comparison with ANT and ANQ exposure, as evidenced by the values of integrated biomarker response (IBR) following the order of EPFRs (14.5) > ANT (12.8) > ANQ (10.9). Moreover, high-throughput sequencing found that EPFRs induced dramatic changes in the composition and structure of earthworm gut microbiota, which may involve immune and metabolism dysfunction, in turn aggravated EPFRs toxicity. Overall, the obtained information highlights the more severe injury of EPFRs to terrestrial organisms, deserving more attentions for the assessment of potential risks associated with radical intermediates in PAHs-contaminated soils.
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•ANT-induced EPFRs elicit oxidative stress and histological damage of earthworms.•Gut microbiota dysbiosis induced by EPFRs aggravates the damage of earthworms.•The toxicity of EPFRs was higher than its parent and final transformation products.
Organic acid is prevalent in underground environments and, against the backdrop of biogeochemical cycles on Earth, holds significant importance in the degradation of contaminants by redox-active ...minerals. While earlier studies on the role of organic acid in the generation of reactive oxygen species (ROS) primarily concentrated on electron shuttle or ligand effects, this study delves into the combined impacts of organic acid decomposition and Mackinawite (FeS) oxidation in contaminant transformation under dark aerobic conditions. Using bisphenol A (BPA) as a model, our findings showed that oxalic acid (OA) notably outperforms other acids in enhancing BPA removal, attaining a rate constant of 0.69 h–1. Mass spectrometry characterizations, coupled with anaerobic treatments, advocate for molecule-O2 activation as the principal mechanism behind pollutant transformation. Comprehensive results unveiled that carbon center radicals, initiated by hydroxyl radical (•OH) attack, serve as the primary agents in pollutant oxidation, accounting for at least 93.6% of the total •OH generation. This dynamic, driven by the decomposition of organic acids and the concurrent formation of carbon-centered radicals, ensures a steady supply of electrons for ROS generation. The obtained information highlights the importance of OA decomposition in the natural attenuation of pollutants and offers innovative strategies for FeS and organic acid-coupled decontamination.
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