1,154 research outputs found
Antibacterial, antioxidant and anti-proliferative properties and zinc content of five south Portugal herbs
Context: Crataegus monogyna L. (Rosaceae) (CM), Equisetum telmateia L. (Equisataceae) (ET), Geranium purpureum Vil. (Geraniaceae) (GP), Mentha suaveolens Ehrh. (Lamiaceae) (MS), and Lavandula stoechas L. spp. luisieri (Lamiaceae) (LS) are all medicinal. Objective: To evaluate the antioxidant, antiproliferative and antimicrobial activities of plant extracts and quantify individual phenolics and zinc. Material and methods: Aerial part extracts were prepared with water (W), ethanol (E) and an 80% mixture (80EW). Antioxidant activity was measured with TAA, FRAP and RP methods. Phenolics were quantified with a HPLC. Zinc was quantified using voltammetry. Antibacterial activity (after 48 h) was tested using Enterococcus faecalis, Bacillus cereus, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Listeria monocytogenes. Antiproliferative activity (after 24 h) was tested using HEP G2 cells and fibroblasts. Results: Solvents influenced results; the best were E and 80EW. GP had the highest antioxidant activity (TAA and FRAP of 536.90mg AAE/g dw and 783.48mg TE/g dw, respectively). CM had the highest zinc concentration (37.21 mg/kg) and phenolic variety, with neochlorogenic acid as the most abundant (92.91 mg/100 g dw). LS was rich in rosmarinic acid (301.71 mg/100 g dw). GP and LS inhibited the most microorganisms: B. cereus, E. coli and S. aureus. GP also inhibited E. faecalis. CM had the lowest MIC: 5830 mu g/mL. The antibacterial activity is explained by the phenolics present. LS and CM showed the most significant anti-proliferative activity, which is explained by their zinc content. Conclusion: The most promising plants for further studies are CM, LS and GP.FCT, Fundacao para a Ciencia e a Tecnologia of Portugal [SFRH/BSA/139/2014
Metformin and weight loss in obese women with polycystic ovary syndrome: comparison of doses
CONTEXT: Metformin treatment of women with polycystic ovary syndrome (PCOS) is widespread, as determined by studies with diverse patient populations. No comparative examination of weight changes or metabolite responses to different doses has been reported. OBJECTIVE: The aim of this study was to determine whether different doses of metformin (1500 or 2550 mg/d) would have different effects on body weight, circulating hormones, markers of inflammation, and lipid profiles. DESIGN: The study included prospective cohorts randomized to two doses of metformin. SETTING: The study was performed at a university teaching hospital with patients from gynecology/endocrinology clinics. PATIENTS: The patients studied were obese (body mass index, 30 to or =37 kg/m2; n = 41) women with PCOS. INTERVENTION: Patients were randomized to two doses of metformin, and parameters were assessed after 4 and 8 months. MAIN OUTCOME MEASURES: The main outcome measures were changes in body mass, circulating hormones, markers of inflammation, and lipid profiles. Results: Intention to treat analyses showed significant weight loss in both dose groups. Only the obese subgroup showed a dose relationship (1.5 and 3.6 kg in 1500- and 2550-mg groups, respectively; P = 0.04). The morbidly obese group showed similar reductions (3.9 and 3.8 kg) in both groups. Suppression of androstenedione was significant with both metformin doses, but there was no clear dose relationship. Generally, beneficial changes in lipid profiles were not related to dose. CONCLUSION: Weight loss is a feature of protracted metformin therapy in obese women with PCOS, with greater weight reduction potentially achievable with higher doses. Additional studies are required to determine whether other aspects of the disorder may benefit from the higher dose of metformin
IMPROvER : the Integral Membrane Protein Stability Selector
Identifying stabilising variants of membrane protein targets is often required for structure determination. Our new computational pipeline, the Integral Membrane Protein Stability Selector (IMPROvER) provides a rational approach to variant selection by employing three independent approaches: deep-sequence, model-based and data-driven. In silico tests using known stability data, and in vitro tests using three membrane protein targets with 7, 11 and 16 transmembrane helices provided measures of success. In vitro, individual approaches alone all identified stabilising variants at a rate better than expected by random selection. Low numbers of overlapping predictions between approaches meant a greater success rate was achieved (fourfold better than random) when approaches were combined and selections restricted to the highest ranked sites. The mix of information IMPROvER uses can be extracted for any helical membrane protein. We have developed the first general-purpose tool for selecting stabilising variants of alpha -helical membrane proteins, increasing efficiency and reducing workload. IMPROvER can be accessed at http://improver.ddns.net/IMPROvER/.Peer reviewe
Izolacija i sposobnost hvatanja slobodnih radikala cijanidin 3-O-glikozida iz plodova Ribes biebersteinii Berl.
The reversed-phase preparative high performance liquid chromatographic purification of the methanol extract of the fruits of Ribes biebersteinii Berl. (Grossulariaceae) afforded five cyanidin glycosides, 3-O-sambubiosyl-5-O-glucosyl cyanidin (1), cyanidin 3-O-sambubioside (2), cyanidin 3-O-glucoside (3), cyanidin 3-O-(2G-xylosyl)-rutinoside (4) and cyanidin 3-O-rutinoside (5). They showed considerable free-radical-scavenging properties in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay with the RC50 values of 9.29 Ă 106, 9.33 Ă 106, 8.31 Ă 106, 8.96 Ă 106 and 9.55 Ă 106 mol L1, respectively. The structures of these compounds were elucidated by various chemical hydrolyses and spectroscopic means. The total anthocyanin content was 1.9 g per 100 g dried fruits on cyanidin 3-glucoside basis.Pet cijanidin glikozida, 3-O-sambubiozil-5-O-glukozil cijanidin (1), cijanidin 3-O-sambubiozid (2), cijanidin 3-O-glukozid (3), cijanidin 3-O-(2G-ksilozil)-rutinozid (4) i cijanidin 3-O-rutinosid (5) izolirani su iz metanolnog ekstrakta plodova Ribes biebersteinii Berl. (Grossulariaceae) koristeÄi reverzno-faznu preparativnu tekuÄinsku kromatografiju visoke uÄinkovitosti. Cijanidin glikozidi pokazali su sposobnost hvatanja slobodnih radikala u pokusu s 2,2-difenil-1-pikrilhidrazilom (DPPH). Dobivene su sljedeÄe RC50 vrijednosti: 9,29 Ă 106, 9,33 Ă 106, 8,31 Ă 106, 8,96 Ă 106, odnosno 9,55 Ă 106 mol L1. Strukture glikozida odreÄene su kemijskom hidrolizom i spektroskopijom masa. Ukupni sadrĆŸaj antocijanina bio je 1,9 g na 100 g suhih plodova preraÄunato na cijanidin 3-glukozid
Influence of Speed, Ground Surface and Shoeing Condition on Hoof Breakover Duration in Galloping Thoroughbred Racehorses
Understanding the effect of horseshoeâsurface combinations on hoof kinematics at gallop is relevant for optimising performance and minimising injury in racehorseâjockey dyads. This intervention study assessed hoof breakover duration in Thoroughbred ex-racehorses from the British Racing School galloping on turf and artificial tracks in four shoeing conditions: aluminium, barefoot, aluminiumârubber composite (GluShu) and steel. Shoeâsurface combinations were tested in a randomized order and horseâjockey pairings (n = 14) remained constant. High-speed video cameras (Sony DSC-RX100M5) filmed the hoof-ground interactions at 1000 frames per second. The time taken for a hoof marker wand fixed to the lateral hoof wall to rotate through an angle of 90 degrees during 384 breakover events was quantified using Tracker software. Data were collected for leading and non-leading forelimbs and hindlimbs, at gallop speeds ranging from 23â56 km hâ1. Linear mixed-models assessed whether speed, surface, shoeing condition and any interaction between these parameters (fixed factors) significantly affected breakover duration. Day and horseâjockey pair were included as random factors and speed was included as a covariate. The significance threshold was set at p \u3c 0.05. For all limbs, breakover times decreased as gallop speed increased (p \u3c 0.0005), although a greater relative reduction in breakover duration for hindlimbs was apparent beyond approximately 45 km hâ1. Breakover duration was longer on turf compared to the artificial surface (p †0.04). In the non-leading hindlimb only, breakover duration was affected by shoeing condition (p = 0.025) and an interaction between shoeing condition and speed (p = 0.023). This work demonstrates that speed, ground surface and shoeing condition are important factors influencing the galloping gait of the Thoroughbred racehorse
OMEGAâOSIRIS mapping of emission-line galaxies in A901/2:IV. Extinction of star formation estimators with inclination
We study the effect of inclination on the apparent brightness of star-forming galaxies in spectral passbands that are commonly used as star formation indicators. As diagnostics we use mass-to-light ratios in three passbands: the UV continuum at 280 nm, the Hα emission line, and the FIR 24ÎŒ band. We include a study of inclination trends in the IR/UV ratio (âIRXâ) and the IR/Hα ratio. Our sample comprises a few hundred galaxies from the region around the clusters Abell 901/902 with deep data and inclinations measured from outer discs in Hubble Space Telescope images. As a novelty, the Hα- and separately the N ii emission are measured by tunable-filter imaging and encompass galaxies in their entirety. At galaxy stellar masses above logâM*/Mâ âł 10 we find trends in the UV and Hα mass-to-light ratio that suggest an inclination-induced attenuation from face-on to edge-on of âŒ1 mag and âŒ0.7 mag in UV and Hα, respectively, implying that star formation rates of edge-on galaxies would be underestimated by âŒ2.5 Ă in UV and âŒ2 Ă in Hα. We find the luminosities in UV and Hα to be well correlated, but the optical depth of diffuse dust that causes inclination dependence appears to be lower for stars emitting at 280 nm than for gas clouds emitting Balmer lines. For galaxies with logâM*/Mâ âČ 9.7, we find no measurable effect at >0.1 mag. The absence of an inclination dependence at 24ÎŒ confirms that the average galaxy is optically thin in the FIR
Mangroves enhance the biomass of coral reef fish communities in the Caribbean
Mangrove forests are one of the world's most threatened tropical ecosystems with global loss exceeding 35% (ref. 1). Juvenile coral reef fish often inhabit mangroves, but the importance of these nurseries to reef fish population dynamics has not been quantified. Indeed, mangroves might be expected to have negligible influence on reef fish communities: juvenile fish can inhabit alternative habitats and fish populations may be regulated by other limiting factors such as larval supply or fishing. Here we show that mangroves are unexpectedly important, serving as an intermediate nursery habitat that may increase the survivorship of young fish. Mangroves in the Caribbean strongly influence the community structure of fish on neighbouring coral reefs. In addition, the biomass of several commercially important species is more than doubled when adult habitat is connected to mangroves. The largest herbivorous fish in the Atlantic, Scarus guacamaia, has a functional dependency on mangroves and has suffered local extinction after mangrove removal. Current rates of mangrove deforestation are likely to have severe deleterious consequences for the ecosystem function, fisheries productivity and resilience of reefs. Conservation efforts should protect connected corridors of mangroves, seagrass beds and coral reefs
The distribution of stellar orbits in eagle galaxies â the effect of mergers, gas accretion, and secular evolution
The merger history of a galaxy is thought to be one of the major factors determining its internal dynamics, with galaxies having undergone different types or mergers (e.g. dry, minor, or major mergers) predicted to show different dynamical properties. We study the instantaneous orbital distribution of galaxies in the EAGLE simulation, colouring the orbits of the stellar particles by their stellar age, in order to understand whether stars form in particular orbits (e.g. in a thin or thick disc). We first show that EAGLE reproduces well the observed stellar mass fractions in different stellar orbital families as a function of stellar mass and spin parameter at z = 0. We find that the youngest stars reside in a thin disc component that can extend to the very inner regions of galaxies, and that older stars have warmer orbits, with the oldest ones showing orbits consistent with both hot and counter-rotating classifications, which is consistent with the trend found in the Milky Way and other disc galaxies. We also show that counter-rotating orbits trace galaxy mergers â in particular dry mergers, and that in the absence of mergers, counter-rotating orbits can also be born from highly misaligned gas accretion that leads to star formation
- âŠ