Mechanical and liquid phase exfoliation of cylindrite: A natural van der Waals superlattice with intrinsic magnetic interactions

We report the isolation of thin flakes of cylindrite, a naturally occurring van der Waals superlattice, by means of mechanical and liquid phase exfoliation. We find that this material is a heavily doped p-Type semiconductor with a narrow gap (<0.85 eV) with intrinsic magnetic interactions that are preserved even in the exfoliated nanosheets. Due to its environmental stability and high electrical conductivity, cylindrite can be an interesting alternative to the existing 2D magnetic materials

Mefloquine pharmacokinetics and mefloquine-artesunate effectiveness in Peruvian patients with uncomplicated Plasmodium falciparum malaria

<p>Abstract</p> <p>Background</p> <p>Artemisinin-based combination therapy (ACT) is recommended as a means of prolonging the effectiveness of first-line malaria treatment regimens. Different brands of mefloquine (MQ) have been reported to be non-bioequivalent; this could result in sub-therapeutic levels of mefloquine with decreased efficacy. In 2002, mefloquine-artesunate (MQ-AS) combination therapy was adopted as the first-line treatment for uncomplicated <it>Plasmodium falciparum </it>malaria in the Amazon region of Peru. Although MQ resistance has yet to be reported from the Peruvian Amazon, it has been reported from other countries in the Amazon Region. Therefore, continuous monitoring is warranted to ensure that the first-line therapy remains efficacious. This study examines the <it>in vivo </it>efficacy and pharmacokinetic parameters through Day 56 of three commercial formulations of MQ (Lariam^®, Mephaquin^®, and Mefloquina-AC^®Farma) given in combination with artesunate.</p> <p>Methods</p> <p>Thirty-nine non-pregnant adults with <it>P. falciparum </it>mono-infection were randomly assigned to receive artesunate in combination with either (1) Lariam, (2) Mephaquin, or (3) Mefloquina AC. Patients were assessed on Day 0 (with blood samples for pharmacokinetics at 0, 2, 4, and 8 hours), 1, 2, 3, 7, and then weekly until day 56. Clinical and parasitological outcomes were based on the standardized WHO protocol.</p> <p>Whole blood mefloquine concentrations were determined by high-performance liquid chromatography and pharmacokinetic parameters were determined using non-compartmental analysis of concentration versus time data.</p> <p>Results</p> <p>By day 3, all patients had cleared parasitaemia except for one patient in the AC Farma arm; this patient cleared by day 4. No recurrences of parasitaemia were seen in any of the 34 patients. All three MQ formulations had a terminal half-life of 14–15 days and time to maximum plasma concentration of 45–52 hours. The maximal concentration (C_max) and interquartile range was 2,820 ng/ml (2,614–3,108) for Lariam, 2,500 ng/ml (2,363–2,713) for Mephaquin, and 2,750 ng/ml (2,550–3,000) for Mefloquina AC Farma. The pharmacokinetics of the three formulations were generally similar, with the exception of the C_maxof Mephaquin which was significantly different to that of Lariam (<it>p </it>= 0.04).</p> <p>Conclusion</p> <p>All three formulations had similar pharmacokinetics; in addition, the pharmacokinetics seen in this Peruvian population were similar to reports from other ethnic groups. All patients rapidly cleared their parasitaemia with no evidence of recrudescence by Day 56. Continued surveillance is needed to ensure that patients continue to receive optimal therapy.</p

Physiological effects of dietary inulin, xylitol and β-galactosyl-derivatives of sugar alcohols in rat

Rats were fed for 4 weeks with diets containing 5% sucrose or the following preparations: inulin, xylitol or b-galactosyl-derivatives of polyol (b-galactosyl-xylitol, -sorbitol, -erythritol). Except for b-galactosyl-erythritol, all preparations caused an enlargement of caecum weight (tissue: 0.41-0.51, digesta: 1.28-1.80 g/100 g BW), compared to the control group (0.28 and 1.00, respectively). The control caecal pH was close to 7.0, while in the experimental groups it ranged from 6.45 (xylitol) to 6.84 (b-galactosyl-erythritol). The caecal ammonia concentration was the lowest in the inulin group (0.45 mg g-1) and the highest in ß-galactosyl-sorbitol group (0.62). All preparations decreased the b-glucuronidase activity in the caecal digesta (0.59-0.81 U g-1) compared to rats fed sucrose-diet (1.00). The highest concentration of SCFAs in the caecum was in inulin and b-galactosyl-erythritol groups (68.57 and 68.36 µmol g-1), and the lowest one - with xylitol (52.41). The total production of SCFAs in the caecum (µmol/100 g BW) was the lowest in the control group (64.8)