27 research outputs found

    Numerical analysis of the light modulation by the frustule of Gomphonema parvulum : the role of integrated optical components

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    Siliceous diatom frustules present a huge variety of shapes and nanometric pore patterns. A better understanding of the light modulation by these frustules is required to determine whether or not they might have photobiological roles besides their possible utilization as building blocks in photonic applications. In this study, we propose a novel approach for analyzing the near-field light modulation by small pennate diatom frustules, utilizing the frustule of Gomphonema parvulum as a model. Numerical analysis was carried out for the wave propagation across selected 2D cross-sections in a statistically representative 3D model for the valve based on the finite element frequency domain method. The influences of light wavelength (vacuum wavelengths from 300 to 800 nm) and refractive index changes, as well as structural parameters, on the light modulation were investigated and compared to theoretical predictions when possible. The results showed complex interference patterns resulting from the overlay of different optical phenomena, which can be explained by the presence of a few integrated optical components in the valve. Moreover, studies on the complete frustule in an aqueous medium allow the discussion of its possible photobiological relevance. Furthermore, our results may enable the simple screening of unstudied pennate frustules for photonic applications

    Crocin mitigates carbon tetrachloride-induced liver toxicity in rats

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    AbstractObjectivesCarbon tetrachloride (CCl4) is one of the most dangerous hepatotoxic environmental pollutants thus this study aimed at investigating the potential preventive effect and mechanism of crocin against CCl4-induced hepatotoxicity.MethodsForty Male rats were allocated for two weeks treatment with; corn oil, CCl4 in corn oil, crocin (100mg/kg), or crocin plus CCl4. At time of euthanasia liver was removed, weighted and processed for histopathological evaluation and estimation of liver contents of active caspase3, lipid peroxidation (MDA) and reduced glutathione (GSH). We also evaluated antioxidant enzymes activities [superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT)], phase I metabolizing enzyme [cytochrome P450 sub family 2E1 (CYP2E1)] an Phase II metabolizing enzyme, [glutathione-S-transferase (GST)] in liver tissue. Blood samples were used for evaluation of liver function tests and inflammatory cytokines [interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α)].ResultsCCl4 induced significant (p < 0.001), increase in: relative liver weight to body weight, liver MDA content, liver active caspase-3 and plasma levels of IL-6 and TNF-α. In addition, CCl4 disturbed liver histology, liver metabolizing enzymes (CYP2E1 and GST), and liver function tests (aspartate aminotransferase, alanine aminotransferase, total bilirubin and alkaline phosphatase). CCl4 induced significant decrease in activities of SOD, CAT, GSH-Px and GSH content. Administration of crocin with CCl4 mitigated all CCl4-disturbed parameters and preserved liver histology close to normal.ConclusionCrocin ameliorated CCl4-induced liver injury via inhibition of inflammatory cytokines, caspase3 and oxidative stress along with modulation of liver metabolizing enzymes favoring elimination of CCl4 toxic metabolite

    Five-year study assessing the clinical utility of anti-Müllerian hormone measurements in reproductive-age women with cancer

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    An important discussion point before chemotherapy is ovarian toxicity, a side-effect that profoundly affects young women with cancer. Their quality of life after successful treatment, including the ability to conceive, is a major concern. We asked whether serum anti-Müllerian hormone (AMH) measurements before chemotherapy for two most common malignancies are predictive of long-term changes in ovarian reserve? A prospective cohort study measured serum AMH in 66 young women with lymphoma and breast cancer, before and at 1 year and 5 years after chemotherapy, compared with 124 healthy volunteers of the same age range (18-43 years). Contemporaneously, patients reported their menses and live births during 5-year follow-up. After adjustment for age, serum AMH was 1.4 times higher (95% CI 1.1 to 1.9; P < 0.02) in healthy volunteers than in cancer patients before chemotherapy. A strong correlation was observed between baseline and 5-year AMH in the breast cancer group (P < 0.001, regression coefficient = 0.58, 95% CI 0.29 to 0.89). No significant association was found between presence of menses at 5 years and serum AMH at baseline (likelihood ratio test from logistics regression analysis). Reproductive-age women with malignancy have lower serum AMH than healthy controls even before starting chemotherapy. Pre-chemotherapy AMH was significantly associated with long-term ovarian function in women with breast cancer. At key time points, AMH measurements could be used as a reproductive health advisory tool for young women with cancer. Our results highlight the unsuitability of return of menstruation as a clinical indicator of ovarian reserve after chemotherapy. [Abstract copyright: Crown Copyright © 2019. Published by Elsevier Ltd. All rights reserved.

    Live birth rates and perinatal outcomes when all embryos are frozen compared with conventional fresh and frozen embryo transfer: a cohort study of 337,148 in vitro fertilisation cycles

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    BACKGROUND: It is not known whether segmentation of an in vitro fertilisation (IVF) cycle, with freezing of all embryos prior to transfer, increases the chance of a live birth after all embryos are transferred. METHODS: In a prospective study of UK Human Fertilisation and Embryology Authority data, we investigated the impact of segmentation, compared with initial fresh embryo followed by frozen embryo transfers, on live birth rate and perinatal outcomes. We used generalised linear models to assess the effect of segmentation in the whole cohort, with additional analyses within women who had experienced both segmentation and non-segmentation. We compared rates of live birth, low birthweight (LB

    Effects of some plant extracts, bioagents, and organic compounds on botrytis and sclerotinia molds

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    Botrytis cinerea and Sclerotinia sclerotiorum are necrotrophic fungi and are closely related pathogenic fungi that infect hundreds of plant species worldwide. In this study, the natural botryticidal/scleroticidal efficacy of some plant extracts, bioagents, and organic compounds known to possess antifungal activity was evaluated. Pathogenicity tests of the fungal molds showed virulence divergence, depending on the isolate and host plant. All B.cinerea isolates, except the BF isolate that infected only broad bean leaves, demonstrated ability to infect detached lettuce and broad bean leaves. Moreover, all Sclerotinia sclerotiorum isolates, except for SSP, demonstrated ability to infect the two plant species, whereas the SSB isolate did not cause any infection in broad bean leaves. The efficacies of Moringa oleifera (Mor), Cinnamomum zeylanicum (Cin), amino acid derivatives (Aad), Trichoderma harzianum (TH), Cactus spp. (Agr), and Bacillus subtilis (BS) were tested either in vitro or in vivo against the highly virulent isolates of the two pathogenic fungi. The efficacy of most potential biofungicides was consistent in vitro as well as in vivo, and the inhibitory efficacy of TH, BS, Cin, Mor, and Aad treatments was significantly high against Botrytis cinerea and Sclerotinia sclerotiorum in vitro and ranged from 62% to 100%, depending on the isolate. In addition, BS, Aad, TH, and Mor treatments had significant inhibitory effects ranging from 53% to 100% against most of the isolates on lettuce leaves. The Agr and Cin treatments exhibited low or no inhibitory effects against many isolates in vivo, and they reduced the mold infection caused by only BCC and SSB isolates. Most of the tested potential biofungicide treatments tended to reduce mold infections, and some of them, such as Cin, exhibited a higher inhibitory effect in vitro than the others. Real-time PCR was conducted for some symptomatic/asymptomatic samples, and the results showed either consistent molecular/symptomatic patterns or latency of B. cinerea. The results confirmed the suitability of the studied natural compounds as effective biofungicides, and they could be the best choice to safely control the most destructive fungal molds
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