Knowledge, attitudes, practices and acceptability of a school preventive chemotherapy programme for schistosomiasis and soil-transmitted helminths control in Angola

Schistosomiasis and soil-transmitted helminth (STH) control programs require target population engagement, assessed through knowledge, attitudes and practices (KAP) surveys. We report the results of a KAP survey of Angolan schoolchildren supported by a school preventive chemotherapy (PC) programme, without or with a school water, sanitation and hygiene (WASH) programme (PC+/WASH- and PC+/WASH+, respectively); and schoolchildren without a school PC or WASH program (PC-/WASH-). Schoolchildren from PC+/WASH- (N = 218), PC+/WASH+ (N = 250) and PC-/WASH- (N = 254) schools were interviewed. Descriptive statistics were used to report demographics and survey responses. Chi-square or Fisher's exact test was used to compare PC+/WASH- schoolchildren with (i) PC+/WASH+ and (ii) PC-/WASH- schoolchildren. A lower proportion of PC+/WASH- schoolchildren used latrines and a higher proportion practised open defecation at school compared with PC+/WASH+ schoolchildren. A lower proportion of PC+/WASH- schoolchildren always washed their hands after toileting and before meals at school compared with PC+/WASH+ schoolchildren. However, the PC+/WASH- schoolchildren reported better toileting and handwashing practices at school compared to PC-/WASH- schoolchildren. Over 90% of PC+ schoolchildren agreed with schistosomiasis and STH control and accepted schoolteacher PC delivery. Expanding the integration of both school PC and WASH programs will improve health behaviours relevant to reduce the risk of schistosomiasis and STHs in schoolchildren. This article is part of the theme issue 'Challenges and opportunities in the fight against neglected tropical diseases: a decade from the London Declaration on NTDs'

A translational approach to studying preterm labour

Preterm labour continues to be a major contributor to neonatal and infant morbidity. Recent data from the USA indicate that the number of preterm deliveries (including those associated with preterm labour) has risen in the last 20 years by 30%. This increase is despite considerable efforts to introduce new therapies for the prevention and treatment of preterm labour and highlights the need to assess research in this area from a fresh perspective. In this paper we discuss i) the limitations of our knowledge concerning prediction, prevention and treatment of preterm labour and ii) future multidisciplinary strategies for improving our approach

The effect of the electric field on lag phase, β-galactosidase production and plasmid stability of a recombinant Saccharomyces cerevisiae strain growing on lactose

Ethanol and β-galactosidase production from cheese whey may significantly contribute to minimise environmental problems while producing value from lowcost raw materials. In this work, the recombinant Saccharomyces cerevisiae NCYC869-A3/pVK1.1 flocculent strain expressing the lacA gene (coding for β-galactosidase) of Aspergillus niger under ADHI promoter and terminator was used. This strain shows high ethanol and β-galactosidase productivities when grown on lactose. Batch cultures were performed using SSlactose medium with 50 gL−1 lactose in a 2-L bioreactor under aerobic and microaerophilic conditions. Temperature was maintained at 30 °C and pH 4.0. In order to determine the effect of an electric field in the fermentation profile, titanium electrodes were placed inside the bioreactor and different electric field values (from 0.5 to 2 Vcm−1) were applied. For all experiments, β-galactosidase activity, biomass, protein, lactose, glucose, galactose and ethanol concentrations were measured. Finally, lag phase duration and specific growth rate were calculated. Significant changes in lag phase duration and biomass yield were found when using 2 Vcm−1. Results show that the electric field enhances the early stages of fermentation kinetics, thus indicating that its application may improve industrial fermentations’ productivity. The increase in electric field intensity led to plasmid instability thus decreasing β-galactosidase production.The authors gratefully acknowledge Fundacao para a Ciencia e a Tecnologia (Portugal) for the scholarships SFRH/BD/11230/2002 and SFRH/BDP/63831/2009 granted to authors I. Castro and C. Oliveira, respectively

Influence of temperature and applied potential on the permeability of polyphenol films prepared on vitreous carbon in acid and alkaline media

The electrochemical polymerization of phenol is known to rapidly produce a thin insulating film at the anode surface. This film generally blocks further polymerization. The objective of this study is to show that, depending on the operating conditions, polymeric films resulting from phenol oxidation present different properties and that certain films can be so porous that they allow the oxidation of phenol to continue. The deposition of polyphenol films with improved permeability could be attractive in the removal of phenol from polluted solutions. Polyphenol films were prepared in aqueous solution on a vitreous carbon anode either by cyclic voltammetry or by electro-oxidation at constant potential. The apparent permeability P (%) of the films prepared by these techniques was evaluated by monitoring changes in the electrode response towards phenol and potassium ferricyanide at 25 and 85°C and as a function of the potential applied during electropolymerization performed either in acidic (1 mol L-¹H₂SO₄) or in alkaline (1 mol L-¹ NaOH) aqueous solution. It was shown that: (1) the polyphenol film electrosynthesized in alkaline medium was more permeable than that prepared in acidic medium, (2) the apparent permeability was higher when the polyphenol film was electrosynthesized with simultaneous oxygen evolution and (3) the use of a high temperature in the polyphenol film preparation, especially in the presence of a concomitant oxygen evolution, significantly enhanced its apparent permeability (P ≥ 100 %). These results are interpreted in terms of a mixed-transport mechanism involving both pore and membrane diffusion. The effect of the permeability of the polymeric film on the removal of phenol from aqueous solution by electropolymerization is discussed

Respiratory disease and the role of oral bacteria

The relationship between oral health and systemic conditions, including the association between poor oral hygiene, periodontal disease, and respiratory disease, has been increasingly debated over recent decades. A considerable number of hypotheses have sought to explain the possible role of oral bacteria in the pathogenesis of respiratory diseases, and some clinical and epidemiological studies have found results favoring such an association. This review discusses the effect of oral bacteria on respiratory disease, briefly introduces the putative biological mechanisms involved, and the main factors that could contribute to this relationship. It also describes the role of oral care for individuals who are vulnerable to respiratory infections

Influence of temperature and applied potential on the permeability of polyphenol films prepared on vitreous carbon in acid and alkaline media

The electrochemical polymerization of phenol is known to rapidly produce a thin insulating film at the anode surface. This film generally blocks further polymerization. The objective of this study is to show that, depending on the operating conditions, polymeric films resulting from phenol oxidation present different properties and that certain films can be so porous that they allow the oxidation of phenol to continue. The deposition of polyphenol films with improved permeability could be attractive in the removal of phenol from polluted solutions. Polyphenol films were prepared in aqueous solution on a vitreous carbon anode either by cyclic voltammetry or by electro-oxidation at constant potential. The apparent permeability P (%) of the films prepared by these techniques was evaluated by monitoring changes in the electrode response towards phenol and potassium ferricyanide at 25 and 85°C and as a function of the potential applied during electropolymerization performed either in acidic (1 mol L-¹H₂SO₄) or in alkaline (1 mol L-¹ NaOH) aqueous solution. It was shown that: (1) the polyphenol film electrosynthesized in alkaline medium was more permeable than that prepared in acidic medium, (2) the apparent permeability was higher when the polyphenol film was electrosynthesized with simultaneous oxygen evolution and (3) the use of a high temperature in the polyphenol film preparation, especially in the presence of a concomitant oxygen evolution, significantly enhanced its apparent permeability (P ≥ 100 %). These results are interpreted in terms of a mixed-transport mechanism involving both pore and membrane diffusion. The effect of the permeability of the polymeric film on the removal of phenol from aqueous solution by electropolymerization is discussed

Optimisation of the conditions for stripping voltammetric analysis at liquid-liquid interfaces supported at micropore arrays: a computational simulation

Micropore membranes have been used to form arrays of micro interfaces between immiscible electroly tesolutions (μITIES) as a basis for the sensing of non-redoxactiveions. Implementation of stripping voltammetry as asensing method at these arrays of μITIES was applied recently to detect drugs and biomolecules at low concentrations. The present study uses computational simulation to investigate the optimum conditions for stripping voltammetricsensing at the μITIES array. In this scenario, thediffusion of ions in both the aqueous and the organic phasescontributes to the sensing response. The influence of the preconcentration time, the micropore aspect ratio, the location of the micro interface within the pore, the ratio of the diffusion coefficients of the analyte ion in the organic and aqueous phases, and the pore wall angle were investigated. The simulations reveal that the accessibility of the microinterfaces during the preconcentration period should not be hampered by a recessed interface and that diffusional transport in the phase where the analyte ions are preconcentrated should be minimized. This will ensure that the ions are accumulated within the micropores close to the interface and thus be readily available for back transferduring the stripping process. On the basis of the results, an optimal combination of the examined parameters is proposed,which together improve the stripping voltammetric signal and provide an improvement in the detection limit

Structural diversity in binary nanoparticle superlattices

Assembly of small building blocks such as atoms, molecules and nanoparticles into macroscopic structures - that is, 'bottom up' assembly - is a theme that runs through chemistry, biology and material science. Bacteria(1), macromolecules(2) and nanoparticles(3) can self-assemble, generating ordered structures with a precision that challenges current lithographic techniques. The assembly of nanoparticles of two different materials into a binary nanoparticle superlattice (BNSL)(3-7) can provide a general and inexpensive path to a large variety of materials (metamaterials) with precisely controlled chemical composition and tight placement of the components. Maximization of the nanoparticle packing density has been proposed as the driving force for BNSL formation(3,8,9), and only a few BNSL structures have been predicted to be thermodynamically stable. Recently, colloidal crystals with micrometre-scale lattice spacings have been grown from oppositely charged polymethyl methacrylate spheres(10,11). Here we demonstrate formation of more than 15 different BNSL structures, using combinations of semiconducting, metallic and magnetic nanoparticle building blocks. At least ten of these colloidal crystalline structures have not been reported previously. We demonstrate that electrical charges on sterically stabilized nanoparticles determine BNSL stoichiometry; additional contributions from entropic, van der Waals, steric and dipolar forces stabilize the variety of BNSL structures.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62551/1/nature04414.pd