207 research outputs found

    Antioxidant and antimicrobial activities of Morchella conica Pers.

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    Antioxidant capacity and antimicrobial activities of Morchella conica Pers. extracts obtained with ethanol were investigated in this study. Four complementary test systems; namely DPPH free radical scavenging, -carotene/linoleic acid systems, total phenolic compounds and total flavonoid concentration were used. Inhibition values of M. conica ethanol extracts, buthylated hydroxyanisol (BHA) and -tocopherol standards were found to be 96.9, 98.9 and 99.2%, respectively, at aconcentration of 160 ìg/ml. When compared the inhibition levels of methanol extract of M. conica and standards in linoleic acid system, it was observed that the higher the concentration of both M. conicaethanol extract and the standards the higher the inhibition effect. Total flavonoid amount was 9.17±0.56ìg mg-1 quercetin equivalent while the phenolic compound amount was 41.93±0.29 ìg mg-1 pyrocatecholequivalent in the ethanolic extract. The antimicrobial effect of M. conica ethanol extract was tested against six species of Gram-positive bacteria, seven species of Gram-negative bacteria and one speciesof yeast. The M. conica ethanol extract had a narrow antibacterial spectrum against tested microorganisms. The most susceptible bacterium was M. flavus. The crude extract was found active on S. aureus ATCC 25923 and S. aureus Cowan I. The M. conica ethanol extract did not exhibit anticandidal activity against C. albican

    Free-radical scavenging capacity and antimicrobial activity of wild edible mushroom from Turkey

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    Antioxidant capacity and antimicrobial activities of Ramaria flava (Schaeff) Quel. (RF) extracts obtained with ethanol were investigated in this study. Four complementary test systems; namely DPPH freeradical scavenging, -carotene/linoleic acid systems, total phenolic compounds and total flavonoid concentration have been used. Inhibition values of R. flava extracts, BHA and -tocopherol standardswere found to be 94.7, 98.9 and 99.2%, respectively, at 160ƒÊg/ml. When compared the inhibition levels of ethanol extract of R. flava and standards in linoleic acid system, it was observed that the higher theconcentration of both RF ethanol extract and the standards the higher the inhibition effect. Total flavonoid amount was 8.27}0.28 ƒÊg mg-1 quercetin equivalent while the total phenolic compound amountwas 39.83}0.32 ƒÊg mg-1 pyrocatechol equivalent in the ethanolic extract. The ethanol extract of R. flava inhibited the growth of Gram-positive bacteria better than Gram-negative bacteria and yeast. The crude extract showed no antibacterial activity against Pseudomonas aeruginosa, Escherichia coli, Morganella morganii and Proteus vulgaris. The antimicrobial activity profile of R. flava against tested strains indicated that Micrococcus flavus, Micrococcus luteus and Yersinia enterocolitica was the most susceptible bacteria of all the test strains. R. flava was found to be inactive against Candida albicans

    Histopathological placental lesions in mild gestational hyperglycemic and diabetic women

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    Objective: To investigate and compare the incidence of histopathological placental lesions in mild gestational hyperglycemia, gestational diabetes and overt diabetes at term and preterm gestation.Research design and methods: One-hundred-and-thirty-one placental samples were collected from Diabetes mellitus (DM) positive screened patients. Two diagnostic tests, glycemic profile and 100 g oral glucose tolerance test (OGTT) in parallel identified 4 groups normoglycemic, mild gestational hyperglycemia (MGH), gestational DM (GDM) or overt DM (DM). Placental tissue specimens and sections from 4 groups were obtained by uniform random sampling and stained with hematoxylin-eosin.Results: Placentas from MGH group presented 17 types of histopathological change and higher rates of syncytial nodes and endarteritis. GDM placentas presented only nine types of histopathological change, high rates of dysmaturity, low rates of calcification and no syncytial nodes. Overt DM placentas showed 22 types of histopathological change, 21 of which were present in the preterm period. There were histopathological similarities between MGH and DM placentas, but the former exhibited a higher incidence of endarteritis, which has been described as a post-mortem phenomenon.Conclusion: Our results confirmed that the distinct placental changes associated with DM and MGH depend on gestational period during which the diabetic insult occurs. It may reasonably be inferred that subclinical maternal hyperglycemia during pregnancy, as showed in MGH group, is responsible for increased placental endarteritis, a postmortem lesion in the live fetus

    Single-lens mass measurement in the high-magnification microlensing event Gaia 19bld located in the Galactic disc

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    CONTEXT: Microlensing provides a unique opportunity to detect non-luminous objects. In the rare cases that the Einstein radius θ_{E} and microlensing parallax π_{E} can be measured, it is possible to determine the mass of the lens. With technological advances in both ground- and space-based observatories, astrometric and interferometric measurements are becoming viable, which can lead to the more routine determination of θ_{E} and, if the microlensing parallax is also measured, the mass of the lens. AIMS: We present the photometric analysis of Gaia19bld, a high-magnification (A ≈ 60) microlensing event located in the southern Galactic plane, which exhibited finite source and microlensing parallax effects. Due to a prompt detection by the Gaia satellite and the very high brightness of I = 9.05 mag at the peak, it was possible to collect a complete and unique set of multi-channel follow-up observations, which allowed us to determine all parameters vital for the characterisation of the lens and the source in the microlensing event. METHODS: Gaia19bld was discovered by the Gaia satellite and was subsequently intensively followed up with a network of ground-based observatories and the Spitzer Space Telescope. We collected multiple high-resolution spectra with Very Large Telescope (VLT)/X-shooter to characterise the source star. The event was also observed with VLT Interferometer (VLTI)/PIONIER during the peak. Here we focus on the photometric observations and model the light curve composed of data from Gaia, Spitzer, and multiple optical, ground-based observatories. We find the best-fitting solution with parallax and finite source effects. We derived the limit on the luminosity of the lens based on the blended light model and spectroscopic distance. RESULTS: We compute the mass of the lens to be 1.13 ± 0.03 M_{⊙} and derive its distance to be 5.52_{−0.64}^{+0.35} kpc. The lens is likely a main sequence star, however its true nature has yet to be verified by future high-resolution observations. Our results are consistent with interferometric measurements of the angular Einstein radius, emphasising that interferometry can be a new channel for determining the masses of objects that would otherwise remain undetectable, including stellar-mass black holes

    Single-lens mass measurement in the high-magnification microlensing event Gaia19bld located in the Galactic disc

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    This work was supported from the Polish NCN grants: Preludium No. 2017/25/N/ST9/01253, Harmonia No. 2018/30/M/ST9/00311, MNiSW grant DIR/WK/2018/12, Daina No. 2017/27/L/ST9/03221, and by the Research Council of Lithuania, grant No. S-LL-19-2. The OGLE project has received funding from the NCN grant MAESTRO 2014/14/A/ST9/00121 to AU. We acknowledge the European Commission’s H2020 OPTICON grant No. 730890. YT acknowledges the support of DFG priority program SPP 1992 “Exploring the Diversity of Extrasolar Planets” (WA 1047/11-1). EB and RS gratefully acknowledge support from NASA grant 80NSSC19K0291. Work by AG was supported by JPL grant 1500811. Work by JCY was supported by JPL grant 1571564. SJF thanks Telescope Live for access to their telescope network. NN acknowledges the support of Data Science Research Center, Chiang Mai University. FOE acknowledges the support from the FONDECYT grant nr. 1201223. MK acknowledges the support from the NCN grant No. 2017/27/B/ST9/02727.Context. Microlensing provides a unique opportunity to detect non-luminous objects. In the rare cases that the Einstein radius θE and microlensing parallax πE can be measured, it is possible to determine the mass of the lens. With technological advances in both ground- and space-based observatories, astrometric and interferometric measurements are becoming viable, which can lead to the more routine determination of θE and, if the microlensing parallax is also measured, the mass of the lens.  Aims. We present the photometric analysis of Gaia19bld, a high-magnification (A approximate to 60) microlensing event located in the southern Galactic plane, which exhibited finite source and microlensing parallax effects. Due to a prompt detection by the Gaia satellite and the very high brightness of I = 9.05 mag at the peak, it was possible to collect a complete and unique set of multi-channel follow-up observations, which allowed us to determine all parameters vital for the characterisation of the lens and the source in the microlensing event.  Methods. Gaia19bld was discovered by the Gaia satellite and was subsequently intensively followed up with a network of ground-based observatories and the Spitzer Space Telescope. We collected multiple high-resolution spectra with Very Large Telescope (VLT)/X-shooter to characterise the source star. The event was also observed with VLT Interferometer (VLTI)/PIONIER during the peak. Here we focus on the photometric observations and model the light curve composed of data from Gaia, Spitzer, and multiple optical, ground-based observatories. We find the best-fitting solution with parallax and finite source effects. We derived the limit on the luminosity of the lens based on the blended light model and spectroscopic distance.  Results. We compute the mass of the lens to be 1.13 ± 0.03 M⊙ and derive its distance to be 5.52-0.64+0.35 kpc. The lens is likely a main sequence star, however its true nature has yet to be verified by future high-resolution observations. Our results are consistent with interferometric measurements of the angular Einstein radius, emphasising that interferometry can be a new channel for determining the masses of objects that would otherwise remain undetectable, including stellar-mass black holes.Publisher PDFPeer reviewe
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