In the present work, a comparative evaluation of an MBBR unit performance was carried out for the following cases: when adding 3D-printed biocarriers fabricated with 13X and bentonite, when using K1 commercial biocarriers and when not adding biocarriers at all. For the evaluation of the MBBR efficiency, various physicochemical parameters were measured, while static light scattering and optical microscopy observations were additionally used. Finally, biofilm extracted from the biocarriers was evaluated. The findings suggest that there is an optimal biodegradation of the organic load in all MBBR units. The nitrification and denitrification process were improved at the 3D MBBR as compared to the control MBBR and MBBR K1. The dry mass of the biofilm in the 3D-printed biocarriers was two orders of magnitude larger than the one in the K1 biocarriers. What is more, in the K1 biocarriers the mass of the biofilm varied in relation to time, due to the fact that it could not be kept inside the holes, something that was not observed to happen with the 3D-printed biocarriers. Finally, it was observed, mostly in the 3D MBBR and less in the K1 MBBR, that the growth of nitrifying bacteria and heterotrophs inside the units increased the biomass production in the form of SMP, which in turn favored the adhesion of biomass on the surface of biocarriers.

For this research, a comparative evaluation was performed in which the addition of 3D-printed biocarriers fabricated with 13X and Halloysite (13Χ-Η) and commercial Kaldnes K1 biocarriers were evaluated as opposed to the non addition of biocarriers in a semi-pilot scale MBBR-MBR unit. For the evaluation of the MBBR-MBR efficiency, various physicochemical parameters were measured while static light scattering and optical microscopy observations were additionally used. Biofilm extracted from the biocarriers was also evaluated. It was observed that in the MBBR-MBR K1 unit, the membrane filtration improved while in the MBBR-MBR 13X-H unit the membrane fouling rate was the same as in the control MBBR-MBR unit. This is due to the production of large amount of SMP which resulted from the large amount of biofilm created in the 13X-H biocarriers. An optimal biodegradation of the organic load was concluded for all three MBBR-MBR units. The nitrification and denitrification processes were improved at the MBBR-MBR units using 13X-H and K1. The dry mass produced on the 13X-H biocarriers was three orders of magnitude larger than that produced on the K1. Finally, it was observed that mostly EPS was produced in the biofilm of K1 biocarriers while in the biofilm of 13X-H mostly SMP.

The present study aimed at investigating the in vitro and in vivo susceptibility of malaria parasites to crude extracts and fractions from Polyalthia suaveolens, Uvaria angolensis, and Monodora tenuifolia. The ethanolic extracts were prepared by maceration, and were further partitioned using water, dichloromethane, hexane, and methanol. The most promising fraction was subjected to column chromatography and the sub-fractions tested for activity in vitro. The antiplasmodial effect of extracts and fractions was tested against the Chloroquine resistant (PfK1) strain in 96 wells microtiter plate format using SYBR green florescence assay. The promising fraction was further assessed for cytotoxicity and acute toxicity in Swiss albino mice and subsequently against the rodent malaria parasite, P. berghei. Qualitative phytochemical screening was also performed on the promising fraction. The methanol fractions exerted the overall better effect with that of the twigs of P. suaveolens (PStw(Ace)) showing the highest potency with a IC50 value of 3.24 µg/mL followed by the fractions of leaf of M. tenuifolia (MoTel(Ace), IC50= 3.84 µg/ml) and stem bark of P. suaveolens (IC50= 4.90 µg/ml). The phytochemical screening showed the presence of alkaloids, lactones, and phenols in the more active fraction of P. suaveolens (PStw(Ace)). The chromatographic fractionation of this fraction led to 12 sub-fractions with PS8 sub-fraction being the most active (IC50= 4.42 µg/mL). In vivo, oral administration of 2000 mg/kg b.w of fraction PStw(Ace) in mice showed no signs of toxicity. Also, fraction PStw(Ace) at 400 mg/kg b.w exerted the highest suppressive effect against P. berghei strain B throughout the 4 days experiment (% parasitaemia below 5.2%). Overall, the results achieved supported the use of the three plants in the traditional treatment of malaria in Cameroon. More interestingly, the methanolic fraction of the twigs extract from P. suaveolens might be of interest in future development of an antimalarial phytodrug.

The pharmacokinetic profile of fat-soluble vitamins A, E, K1, and D3 co-administered with liquid paraffin or water in an experimental rat model was investigated. Animals received a solution of the four vitamins orally through a probe, followed 10 minutes later by the administration of either the liquid paraffin product dissolved in water (Emuliquen Simple®) or water (control). Vitamin formulations were 20, 50, 0.30 and 0.10 mg/kg for vitamins A, E, K1, and D3, respectively. Blood samples were collected before dosing and at 0.17, 1, 2, 4, 8, and 24 hours post-dosing. Vitamin concentrations were quantified by liquid chromatography coupled with mass spectrometry. No relevant differences in the absorption of vitamins in terms of AUC0-last (area under the curve up to the last measurable concentration) or Cmax in the absence or presence of co-administration of the liquid paraffin product were observed. The difference of these parameters between the treatment groups for all vitamins was in the range of bioequivalence (≤ 20%). The liquid paraffin-based laxative product did not interfere with the absorption of vitamins A, E, K1, and D3 that are ingested in the diet, which is clinically relevant due to the high prevalence of functional constipation in children and adults.

Vitamin K occupies a unique and often obscured place among its fellow fat-soluble vitamins. Evidence is mounting however, that vitamin K (VK) may play an important role in the visual system apart from the hepatic carboxylation of hemostatic related proteins. However, to our knowledge, no review covering the topic has appeared in the medical literature. Recent studies have confirmed that matrix Gla protein (MGP), a vitamin K-dependent protein (VKDP), is essential for the regulation of intraocular pressure in the mouse. The PREDIMED (Prevención con Dieta Mediterránea) study, a randomized trial involving 5860 adults at risk for cardiovascular disease, demonstrated a 29% reduction in the risk of cataract surgery in participants with the highest tertile of dietary vitamin K1 (PK) intake compared with the lowest tertile. However, the specific requirements of the eye and visual system (EVS) for VK, and what might constitute an optimized VK status, is currently unknown and largely unexplored. It is the intention therefore of this narrative review to provide an introduction concerning VK and the visual system, review ocular VK biology, and to provide some historical context to recent discoveries. Potential opportunities and gaps in current research efforts will be touched upon, in the hope of raising awareness, and encouraging continued VK related investigations in this important and highly specialized sensory system.