133 research outputs found

    Biosynthesis of spathulenol and camphor stand as a competitive route to artemisinin production as revealed by a new chemometric convergence approach based on nine locations’ field-grown Artemesia annua L.

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    Since isopentenyl diphosphate (IPP) and its isomer dimethylallyl diphosphate (DMAPP) are the universal precursors of both essential oil components, and the antimalarial agent artemisinin and its derivatives in Artemesia annua L., this paper aims to correlate the spotted differences in their concentrations by screening Artemesia annua L. field-grown in nine locations around the world that may reveal the role of any these compounds as precursors or competitors in the biosynthetic pathway of the sesquiterpene lactone : artemisinin. Principal component analysis (PCA) revealed that artemisinin is positively correlated to β-pinene, 1.8-cineole, sabinene hydrate, borneol and 1-octen-3-ol; but negatively to artemisinic acid and β-caryophyllene oxide. Hierarchical cluster analysis (HCA) classified locations into two distinct groups in which artemisinin concentration stood as the main driving factor to build similarities between the locations. In parallel, an improved convergence approach based on idiosyncratic similarities able to capture heterogeneity across individuals is proposed, which was able to classify compounds into four distinct clusters. Artemisinin appeared to be cross-linked to p-cymene, cis-carvyle acetate, 4-terpinene-1-ol, β-caryophyllene, β-farnesene, β-selinene, α-selinene, β-caryophyllene oxide and α-costol. It is interesting to see how camphor and spathulenol behaved as a distinct cluster group, which suggests that biosynthesis of these two compounds follows a different but a competitive pathway ; thus limiting their production could be a key to control and enhance the production of artemisinin

    The benefits of interprofessional education 10 years on.

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    Interprofessional education (IPE) was first conceived in 1973 by a World Health Organization (WHO) expert group in Geneva. WHO member states were then charged with implementing medical education IPE pilot projects and from then to today there has a been a rapid proliferation in the number of publications on the subject. IPE has generated research into its use, conferences specific to IPE, organisations dedicated to it and policy championing it. The authors question whether there has been any major shift in the silos in which different professions might be working. The authors published an article on the benefits of IPE ( Illingworth and Chelvanayagam, 2007 ). Ten years have now passed and many changes have been implemented and experienced in health and social care and therefore a review of the literature is required. Also, it is 7 years since the publication of WHO's report outlining the role of IPE in the preparation of health professionals ( WHO, 2010 ) and, increasingly, UK Government policy champions collaborative and integrated working. The conclusions from the 2007 article acknowledged the development of IPE; however, it highlighted the need for empirical evidence to demonstrate the effectiveness of IPE in service user and carer outcomes. This article will explore whether IPE has achieved the benefits discussed in the previous article and what developments have occurred since it was published

    Is it possible to enhance immune response after vaccination? The role of a probiotic with a proven positive effect on all components of the immune system

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    Preventive vaccination is currently the most affordable and economical way to reduce morbidity and mortality from many infections, improve quality and human life expectancy with an almost ideal balance of benefits and risks among all medical procedures. The article deals with the reasons for variability of the immune response caused by vaccines, between individuals and between populations, which is of fundamental importance for human health. The authors have presented data indicating a key role of the gut microbiota in the control of the immune response to vaccination. Particular attention is paid to the microbial diversity in different loci of the body. The role of microorganisms in the proper functioning of the body and the formation of a number of pathological conditions is described. Most modern vaccines are live-attenuated, killed / inactivated or subunit (recombinant) vaccines, and they are designed for the parenteral route of administration. Most of these vaccines elicit a weak immune response, especially in the mucous membranes, due to the route of administration and are associated with weak cell-mediated immunity. Therefore, mechanisms that can enhance virus-specific vaccine immunity in infants and children are required, such as the use of more potent or selective immunity-enhancing adjuvants. Some probiotic strains may be considered as promising vaccine adjuvants. This article evaluates the recent clinical studies of probiotics used to enhance vaccine-specific immunity in adults and infants. The present-day knowledge on the role of the probiotic strain Lactobacillus rhamnosus GG with the aim of activating immunity after vaccination are presented

    Infant colic: from theory to practice

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    Infant colic is one of the most common, yet least studied, functional disorders of the gastrointestinal tract. Until now, there is no certainty both in the understanding of the nature of this condition and in the approaches to its correction. At the same time, infant crying is of concern to parents, forcing them to seek professional help and incur considerable medical expenses and to resort, sometimes unreasonably, to dietary and medical corrections. This article provides information on the etiology, pathogenesis and management of infantile colic from an evidence-based perspective, based on a review of the current literature. Various preconditions for the occurrence and development of infantile colic are analysed in detail, none of which can affect all occurrences. Evidence for the proven efficacy of including Lactobacillus reuteri in the treatment of intestinal colic in infants is presented. Effects on the gastrointestinal tract microbiome can be of undeniable benefit. Lactobacillus reuteri is one of the most studied and scientifically documented probiotics. 203 completed clinical trials involving 17,200 participants, including 67 trials involving 8,200 participants between 0 and 3 years of age. Numerous placebo-controlled studies have shown that taking Lactobacillus reuteri DSM 17938 can significantly reduce crying time in infants with colic, and in these studies, rates of 50% or more reduction in crying time were 2.3 times higher compared to controls

    Spatially resolved fluorescence of caesium lead halide perovskite supercrystals reveals quasi-atomic behavior of nanocrystals

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    We correlate spatially resolved fluorescence (-lifetime) measurements with X-ray nanodiffraction to reveal surface defects in supercrystals of self-assembled cesium lead halide perovskite nanocrystals and study their effect on the fluorescence properties. Upon comparison with density functional modeling, we show that a loss in structural coherence, an increasing atomic misalignment between adjacent nanocrystals, and growing compressive strain near the surface of the supercrystal are responsible for the observed fluorescence blueshift and decreased fluorescence lifetimes. Such surface defect-related optical properties extend the frequently assumed analogy between atoms and nanocrystals as so-called quasi-atoms. Our results emphasize the importance of minimizing strain during the self-assembly of perovskite nanocrystals into supercrystals for lighting application such as superfluorescent emitters

    Porous Nanocrystalline Silicon Supported Bimetallic Pd-Au Catalysts: Preparation, Characterization, and Direct Hydrogen Peroxide Synthesis.

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    Bimetallic Pd-Au catalysts were prepared on the porous nanocrystalline silicon (PSi) for the first time. The catalysts were tested in the reaction of direct hydrogen peroxide synthesis and characterized by standard structural and chemical techniques. It was shown that the Pd-Au/PSi catalyst prepared from conventional H2[PdCl4] and H[AuCl4] precursors contains monometallic Pd and a range of different Pd-Au alloy nanoparticles over the oxidized PSi surface. The PdAu2/PSi catalyst prepared from the [Pd(NH3)4][AuCl4]2 double complex salt (DCS) single-source precursor predominantly contains bimetallic Pd-Au alloy nanoparticles. For both catalysts the surface of bimetallic nanoparticles is Pd-enriched and contains palladium in Pd0 and Pd2+ states. Among the catalysts studied, the PdAu2/PSi catalyst was the most active and selective in the direct H2O2 synthesis with H2O2 productivity of 0.5 [Formula: see text] at selectivity of 50% and H2O2 concentration of 0.023 M in 0.03 M H2SO4-methanol solution after 5 h on stream at -10°C and atmospheric pressure. This performance is due to high activity in the H2O2 synthesis reaction and low activities in the undesirable H2O2 decomposition and hydrogenation reactions. Good performance of the PdAu2/PSi catalyst was associated with the major part of Pd in the catalyst being in the form of the bimetallic Pd-Au nanoparticles. Porous silicon was concluded to be a promising catalytic support for direct hydrogen peroxide synthesis due to its inertness with respect to undesirable side reactions, high thermal stability, and conductivity, possibility of safe operation at high temperatures and pressures and a well-established manufacturing process

    Wideband 67-116 GHz cryogenic receiver development for ALMA Band 2

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    The Atacama Large Millimeter/sub-millimeter Array (ALMA) is already revolutionising our understanding of the Universe. However, ALMA is not yet equipped with all of its originally planned receiver bands, which will allow it to observe over the full range of frequencies from 35-950 GHz accessible through the Earth's atmosphere. In particular Band 2 (67-90 GHz) has not yet been approved for construction. Recent technological developments in cryogenic monolithic microwave integrated circuit (MMIC) high electron mobility transistor (HEMT) amplifier and orthomode transducer (OMT) design provide an opportunity to extend the originally planned on-sky bandwidth, combining ALMA Bands 2 and 3 into one receiver cartridge covering 67-116 GHz. The IF band definition for the ALMA project took place two decades ago, when 8 GHz of on-sky bandwidth per polarisation channel was an ambitious goal. The new receiver design we present here allows the opportunity to expand ALMA's wideband capabilities, anticipating future upgrades across the entire observatory. Expanding ALMA's instantaneous bandwidth is a high priority, and provides a number of observational advantages, including lower noise in continuum observations, the ability to probe larger portions of an astronomical spectrum for, e.g., widely spaced molecular transitions, and the ability to scan efficiently in frequency space to perform surveys where the redshift or chemical complexity of the object is not known a priori. Wider IF bandwidth also reduces uncertainties in calibration and continuum subtraction that might otherwise compromise science objectives. Here we provide an overview of the component development and overall design for this wideband 67-116 GHz cryogenic receiver cartridge, designed to operate from the Band 2 receiver cartridge slot in the current ALMA front end receiver cryostat.Comment: 8 pages, proceedings from the 8th ESA Workshop on Millimetre-Wave Technology and Applications (https://atpi.eventsair.com/QuickEventWebsitePortal/millimetre-wave/mm-wave

    Anti-plasmodial polyvalent interactions in Artemisia annua L. aqueous extract – possible synergistic and resistance mechanisms

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    Artemisia annua hot water infusion (tea) has been used in in vitro experiments against P. falciparum malaria parasites to test potency relative to equivalent pure artemisinin. High performance liquid chromatography (HPLC) and mass spectrometric analyses were employed to determine the metabolite profile of tea including the concentrations of artemisinin (47.5±0.8 mg L-1), dihydroartemisinic acid (70.0±0.3 mg L-1), arteannuin B (1.3±0.0 mg L-1), isovitexin (105.0±7.2 mg L-1) and a range of polyphenolic acids. The tea extract, purified compounds from the extract, and the combination of artemisinin with the purified compounds were tested against chloroquine sensitive and chloroquine resistant strains of P. falciparum using the DNA-intercalative SYBR Green I assay. The results of these in vitro tests and of isobologram analyses of combination effects showed mild to strong antagonistic interactions between artemisinin and the compounds (9-epi-artemisinin and artemisitene) extracted from A. annua with significant (IC50 <1 μM) anti-plasmodial activities for the combination range evaluated. Mono-caffeoylquinic acids, tri-caffeoylquinic acid, artemisinic acid and arteannuin B showed additive interaction while rosmarinic acid showed synergistic interaction with artemisinin in the chloroquine sensitive strain at a combination ratio of 1:3 (artemisinin to purified compound). In the chloroquine resistant parasite, using the same ratio, these compounds strongly antagonised artemisinin anti-plasmodial activity with the exception of arteannuin B, which was synergistic. This result would suggest a mechanism targeting parasite resistance defenses for arteannuin B’s potentiation of artemisinin
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