We introduce the antibody landscape, a method for the quantitative analysis of antibodymediated immunity to antigenically variable pathogens, achieved by accounting for antigenic variation among ...pathogen strains. We generated antibody landscapes to study immune profiles covering 43 years of influenza A/H3N2 virus evolution for 69 individuals monitored for infection over 6 years and for 225 individuals pre- and postvaccination. Upon infection and vaccination, titers increased broadly, including previously encountered viruses far beyond the extent of cross-reactivity observed after a primary infection. We explored implications for vaccination and found that the use of an antigenically advanced virus had the dual benefit of inducing antibodies against both advanced and previous antigenic clusters. These results indicate that preemptive vaccine updates may improve influenza vaccine efficacy in previously exposed individuals.
Molecular epidemiology and clinical impact of human rhinovirus (HRV) are not well documented in tropical regions. This study compared the clinical characteristics of HRV to other common viral ...infections and investigated the molecular epidemiology of HRV in hospitalized children with acute respiratory infections (ARIs) in Vietnam. From April 2010 to May 2011, 1082 nasopharyngeal swabs were screened for respiratory viruses by PCR. VP4/VP2 sequences of HRV were further characterized. HRV was the most commonly detected virus (30%), in which 70% were diagnosed as either pneumonia or bronchiolitis. Children with single HRV infections presented with significantly higher rate of hypoxia than those infected with respiratory syncytial virus or parainfluenza virus (PIV)-3 (12·4% vs. 3·8% and 0%, respectively, P < 0·05), higher rate of chest retraction than PIV-1 (57·3% vs. 34·5%, P = 0·028), higher rate of wheezing than influenza A (63·2% vs. 42·3%, P = 0·038). HRV-C did not differ to HRV-A clinically. The genetic diversity and changes of types over time were observed and may explain the year-round circulation of HRV. One novel HRV-A type was discovered which circulated locally for several years. In conclusion, HRV showed high genetic diversity and was associated with significant morbidity and severe ARIs in hospitalized children.
We aimed to evaluate the microbiological characteristics and risk factors for mortality of infective endocarditis in two tertiary hospitals in Ho Chi Minh City, south Vietnam.
A retrospective study ...of 189 patients (120 men, 69 women; mean age 38 ± 18 years) with the diagnosis of probable or definite infective endocarditis (IE) according to the modified Duke Criteria admitted to The Heart Institute or Tam Duc Hospital between January 2005 and December 2014.
IE was related to a native valve in 165 patients (87.3%), and prosthetic valve in 24 (12.7%). Of the 189 patients in our series, the culture positive rate was 70.4%. The most common isolated pathogens were Streptococci (75.2%), Staphylococci (9.8%) followed by gram negative organism (4.5%). The sensitivity rate of Streptococci to ampicillin, ceftriaxone or vancomycin was 100%. The rate of methicillin resistant Staphylococcus aureus was 40%. There was a decrease in penicillin sensitivity for Streptococci over three eras: 2005-2007 (100%), 2008-2010 (94%) and 2010-2014 (84%). The in-hospital mortality rate was 6.9%. Logistic regression analysis found prosthetic valve and NYHA grade 3 or 4 heart failure and vegetation size of more than 15 mm as strong predictors of in-hospital mortality.
Streptococcal species were the major pathogen of IE in the recent years with low rates of antimicrobial resistance. Prosthetic valve involvement, moderate or severe heart failure and vegetation size of more than 15 mm were independent predictors for in-hospital mortality in IE.
A series of novel isomeric nickel Schiff base complexes, as well as nickel complexes of related ligands having asymmetric structures have been prepared and characterised using microanalysis, 1H and ...13C NMR spectroscopy and ESI-MS. The Schiff base ligands were prepared by condensation reactions involving ethylenediamine and different derivatives of benzophenone. The solid-state structures of eight of the complexes were also determined and revealed that each possessed a regular square planar coordination geometry around the metal ion. Many of the new complexes featured at least one, and in many instances two, protonatable pendant groups that enhance aqueous solubility. This enabled the DNA binding properties of the latter complexes to be explored using a variety of instrumental approaches, including ESI-MS, circular dichroism (CD) spectroscopy, FRET melting assays and FID assays, as well as molecular docking studies. The results of experiments performed using ESI-MS suggested that none of the nickel complexes exhibit a high affinity towards either a double stranded DNA (dsDNA) molecule D2, or the parallel unimolecular quadruplex DNA (qDNA) molecule Q1. In contrast, complexes (8) and (12) both gave spectra which reflected a significant level of binding to the parallel tetramolecular qDNA Q4. The results of binding experiments performed using CD spectroscopy suggested that (12) exhibits a significant level of affinity towards most types of DNA, while (4) shows a preference for interacting with parallel, unimolecular qDNA molecules. Complex (4) produced the lowest values of DC50 in FID assays performed using parallel Q1 or Q4, confirming its affinity for these qDNA molecules. The results of FRET melting experiments provided further evidence that (12), along with (8), can interact extensively with anti-parallel unimolecular qDNA. Experiments which monitored the effect of the nickel complexes on the melting temperature of D2 showed that none had a stabilising effect on this dsDNA molecule.
Highlights • A review of the current status of Geant4-DNA is presented. • New physical models describing the interactions of electrons in water are described. • Physicochemical and chemical stages of ...water radiolysis can be simulated. • Several approaches are available for modeling geometries of biological targets. • Dedicated examples are proposed to demonstrate such capabilities.
This study explores the potential of removing phosphorus from aqueous solutions and sewage by Zr(IV)-loaded okara (ZLO) in the fixed-bed column. Soybean residue (okara) was impregnated with 0.25M ...Zr(IV) solution to prepare active binding sites for phosphate. The effect of several factors, including flow rate, bed height, initial phosphorus concentration, pH and adsorbent particle size on the performance of ZLO was examined. The maximum dynamic adsorption capacity of ZLO for phosphorus was estimated to be 16.43mg/g. Breakthrough curve modeling indicated that Adams–Bohart model and Thomas model fitted the experimental data better than Yoon–Nelson model. After treatment with ZLO packed bed column, the effluent could meet the discharge standard for phosphorus in Australia. Successful desorption and regeneration were achieved with 0.2 NaOH and 0.1 HCl, respectively. The results prove that ZLO can be used as a promising phosphorus adsorbent in the dynamic adsorption system.
•Dynamic adsorption of P from water and wastewater by Zr(IV)-loaded okara was tested.•Effects of column design parameters on the adsorption performance were investigated.•The dynamic adsorption capacity of Zr(IV)-loaded okara for P was reasonably high.•The spent column was effectively regenerated with 0.2M NaOH followed by 0.1M HCl.•Zr(IV)-loaded okara column was efficient in eliminating P from municipal sewage.
High power tip sonication was used to prepare dispersions containing multi-walled carbon nanotubes (MWNTs), or multi-walled carbon nanotubes functionalised with carboxylic acid groups (MWNT-COOH) or ...amine groups (MWNT-NH2). The dispersion of carbon nanotubes was facilitated by the presence of a surfactant (Triton X-100) or various macrocyclic ligands (derivatised porphyrin, phthalocyanine or calixarene) in the solution. Vacuum filtration of the dispersions afforded self-supporting membranes known as buckypapers. Microanalysis provided evidence for retention of the surfactant or macrocyclic ligands in the buckypapers, which were also characterised by measurement of their electrical conductivities (24±16 to 58±11S/cm), contact angles (28±1° to 55±10°) and mechanical properties (tensile strengths varied between 1.6±0.7 and 13±2MPa). The surface and internal morphologies of the buckypapers were similar to each other, which correlates with the lack of variation observed in their permeability's towards water. The ability of selected buckypapers to remove trace organic contaminants (TrOCs) was also examined. A buckypaper prepared using Triton X-100 as the dispersant showed more than 80% removal efficiency for 11 out of the 12 TrOCs investigated in this study. On the other hand, a buckypaper prepared from MWNTs and phthalocyaninetetrasulfonic acid exhibited lower removal efficiencies for these TrOCs, possibly due to their smaller specific surface area.
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•Multi-walled carbon nanotubes and macrocycles combined to form buckypaper membranes.•All buckypaper membranes shown to be permeable towards water.•All buckypaper membranes removed trace organic contaminants from aqueous solution.
Fine-sized biochars and clay minerals co-present in various circumstances, e.g., agricultural land and water treatment. Because both of these materials are scavengers for nutrients, agrochemicals and ...other toxicants, their dispersibility and transportability have received much attention. However, little is documented about their colloidal interactions and to what extent biochar particles can stimulate the dispersion of clay minerals. Here, the effect of engineered micro-sized biochar amendment on the surface charge (SC) and colloidal dynamics of the clay fraction of a kaolinite-rich soil was determined. The engineered biochars showed distinctive SC and colloidal properties depending on their pyrolysis conditions (e.g., oxygen level and temperature) and solution chemistry (i.e., pH and cation type). Two types of biochars prepared under non-biochar-oriented pyrolysis (open heating, ‘O-biochar’) and biochar-oriented pyrolysis (N2-supported heating, ‘N2-biochar’) showed contrasting effects on the colloidal dynamics of clay. The O-biochars provoked aggregation due to their higher content of soluble salts, which increased ionic strength and provided multivalent cations, inducing bridging between negatively charged colloids. In contrast, the N2 biochars low in soluble salts and rich in negatively charged burned organic matter compounds favoured the dispersion of clay. The adjustment of biochar production methods can therefore be highlighted as the way to customize biochar for specific uses or to reduce the risk of clay loss from soils in the short term. In the long term, when soluble salts are removed by leaching, it is likely that dispersion is facilitated and the risk for erosion increases.
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•Biochar and kaolinitic soil clay of micro size might co-present in many circumstances•Both materials carry a negative surface charge and favour electrostatic interactions.•Biochar drives solution chemistry, thereby altering the colloidal dynamics of soil clay.•The application of biochars will need to be customised for specific cultivation regions.
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