Search

Studies have been carried out to compare the effect of chloride on bacterial growth, iron oxidation activity and bioleaching performance at mesophilic and moderate thermophilic temperatures for chalcopyrite and sphalerite-containing ores. Sulphobacillus thermosulphidooxidans and Leptospirillum ferriphilum were used. It was found that the exposure to elevated NaCl concentration affected cell growth and eventual iron oxidation rate in both strains, with Sb. thermosulphidooxidans having better tolerance to NaCl than L. ferriphilum. The minimum inhibitory concentrations of NaCl were 325 mM and 525 mM for L. ferriphilum and Sb. thermosulphidooxidans, respectively. For copper-containing sulphide minerals, bioleaching by Sb. thermosulphidooxidans in the presence of 200 mM was similar to bioleaching performance in the absence of NaCl. However, in the presence of NaCl, bioleaching by L. ferriphilum reduced by 50 %. For zinc-containing ores. It was found that NaCl significantly inhibited bioleaching by both bacteria. It is concluded that Sb. thermosulphidooxidans can be useful for bioleaching of ores in saline environments due to its high tolerance to chloride, but it is vital to consider that the effect of NaCl to bioleaching can also be mineral-specific., Studies have been carried out to compare the effect of chloride on bacterial growth, iron oxidation activity and bioleaching performance at mesophilic and moderate thermophilic temperatures for chalcopyrite and sphalerite-containing ores. Sulphobacillus thermosulphidooxidans and Leptospirillum ferriphilum were used. It was found that the exposure to elevated NaCl concentration affected cell growth and eventual iron oxidation rate in both strains, with Sb. thermosulphidooxidans having better tolerance to NaCl than L. ferriphilum. The minimum inhibitory concentrations of NaCl were 325 mM and 525 mM for L. ferriphilum and Sb. thermosulphidooxidans, respectively. For copper-containing sulphide minerals, bioleaching by Sb. thermosulphidooxidans in the presence of 200 mM was similar to bioleaching performance in the absence of NaCl. However, in the presence of NaCl, bioleaching by L. ferriphilum reduced by 50 %. For zinc-containing ores. It was found that NaCl significantly inhibited bioleaching by both bacteria. It is concluded that Sb. thermosulphidooxidans can be useful for bioleaching of ores in saline environments due to its high tolerance to chloride, but it is vital to consider that the effect of NaCl to bioleaching can also be mineral-specific.

In March 2016, the Australian government offered unrestricted access to direct-acting antiviral (DAA) therapy for chronic hepatitis C virus (HCV) to the entire population. This included prescription by any medical practitioner in consultation with specialists until sufficient experience was attained. We sought to determine the outcomes and experience over the first twelve months for the entire state of South Australia. We performed a prospective, observational study following outcomes of all treatments associated with the state's four main tertiary centres. A total of 1909 subjects initiating DAA therapy were included, representing an estimated 90% of all treatments in the state. Overall, SVR12 was 80.4% in all subjects intended for treatment and 95.7% in those completing treatment and follow-up. 14.2% were lost to follow-up (LTFU) and did not complete SVR12 testing. LTFU was independently associated with community treatment via remote consultation (OR 1.50, 95% CI 1.04-2.18, P = .03), prison-based treatment (OR 2.02, 95% CI 1.08-3.79, P = .03) and younger age (OR 0.98, 95% CI 0.97-0.99, P = .05). Of the 1534 subjects completing treatment and follow-up, decreased likelihood of SVR12 was associated with genotype 2 (OR 0.23, 95% CI 0.07-0.74, P = .01) and genotype 3 (OR 0.23, 95% CI 0.12-0.43, P ≤ .01). A significant decrease in treatment initiation was observed over the twelve-month period in conjunction with a shift from hospital to community-based treatment. Our findings support the high responses observed in clinical trials; however, a significant gap exists in SVR12 in our real-world cohort due to LTFU. A declining treatment initiation rate and shift to community-based treatment highlight the need to explore additional strategies to identify, treat and follow-up remaining patients in order to achieve elimination targets.

In this paper we review and we extend the reduced basis approximation and a posteriori error estimation for steady Stokes flows in affinely parametrized geometries, focusing on the role played by the Brezzi's and Babuška's stability constants. The crucial ingredients of the methodology are a Galerkin projection onto a low-dimensional space of basis functions properly selected, an affine parametric dependence enabling to perform competitive Offline-Online splitting in the computational procedure and a rigorous a posteriori error estimation on field variables. The combinatiofn of these three factors yields substantial computational savings which are at the basis of an efficient model order reduction, ideally suited for real-time simulation and many-query contexts (e.g. optimization, control or parameter identification). In particular, in this work we focus on (i) the stability of the reduced basis approximation based on the Brezzi's saddle point theory and the introduction of a supremizer operator on the pressure terms, (ii) a rigorous a posteriori error estimation procedure for velocity and pressure fields based on the Babuška's inf-sup constant (including residuals calculations), (iii) the computation of a lower bound of the stability constant, and (iv) different options for the reduced basis spaces construction. We present some illustrative results for both interior and external steady Stokes flows in parametrized geometries representing two parametrized classical Poiseuille and Couette flows, a channel contraction and a simple flow control problem around a curved obstacle