High prevalence of Schistosoma japonicum and Fasciola gigantica in bovines from Northern Samar, the Philippines

The cause of zoonotic schistosomiasis in the Philippines is Schistosoma japonicum, which infects up to 46 mammalian hosts, including humans and bovines. In China, water buffaloes have been identified as major reservoir hosts for schistosomiasis japonica, contributing up to 75% of human transmission. In the Philippines, water buffaloes (carabao; Bubalus bubalis carabanesis) have, historically, been considered unimportant reservoirs. We therefore revisited the possible role of bovines in schistosome transmission in the Philippines, using the recently described formalin-ethyl acetate sedimentation (FEA-SD) technique and a qPCR assay to examine fecal samples from 153 bovines (both carabao and cattle) from six barangays in Northern Samar. A high prevalence of S. japonicum was found using qPCR and FEA-SD in both cattle (87.50% and 77.08%, respectively) and carabao (80.00% and 55.24%, respectively). The average daily egg output for each bovine was calculated at 195,000. High prevalence and infection intensity of F. gigantica was also found in the bovines by qPCR and FEA-SD (95.33% and 96.00%, respectively). The identification of bovines as major reservoir hosts for S. japonicum transmission suggests that bovine treatment and/or vaccination, as one becomes available, should be included in any future control program that aims to reduce the disease burden due to schistosomiasis in the Philippines.

Pathways of the Photocatalytic Reaction of Acetate in H2O and D2O Combined: An EPR and ATR-FTIR Study

The adsorption and photocatalytic degradation of acetate on TiO2 surfaces was investigated in H2O and D2O by ATR-FTIR and EPR Spectroscopy respectively. These studies were carried out in the dark and under UV(A) illumination to gain additional insights into the adsorption behaviour with the identification of paramagnetic species formed during the oxidation of acetate. Isotopic exchange during the adsorption of D2O on TiO2 surface led to different interactions between the adsorbate and OD groups. At different pH levels, several surface complexes of acetate can be formed such as monodentate, or bidentates. Under UV(A) irradiation of TiO2 aqueous suspensions, the formation of hydroxyl and methoxy radicals evidenced as the corresponding spin-adducts, were found to dominate in alkaline and acidic suspensions respectively. Two possible pathways for the oxidation of acetate have been suggested at different pH levels in solution in terms of the source of the spin adduct formed. These proposed pathways were found to be in good agreement with ATR-FTIR and EPR results.

Solvation Structure of Uracil in Ionic Liquids

The local solvation environment of uracil dissolved in the ionic liquid 1-ethyl-3-methylimidazolium acetate has been studied using neutron diffraction techniques. At solvent:solute ratios of 3:1 and 2:1 ionic liquid:uracil, little perturbation of the ion-ion correlations compared to those of the neat ionic liquid are observed. We find that solvation of the uracil is driven predominantly by the acetate anion of the solvent. While short distance correlations exist between uracil and the imidazolium cation, the geometry of these contacts suggest that they cannot be considered as hydrogen bonds, in contrast to other studies by Araújo et al. (J. M. Araújo, A. B. Pereiro, J. N. Canongia-Lopes, L. P. Rebelo, I. M. Marrucho, J. Phys. Chem. B 2013, 117, 4109-4120). Nevertheless, this combination of interactions of the solute with both the cation and anion components of the solvents helps explain the high solubility of the nucleobase in this media. In addition, favorable uracil-uracil contacts are observed, of similar magnitude to those between cation and uracil, and are also likely to aid dissolution