120 research outputs found

    Fatty acid and triacylglycerol compositions of milk thistle seeds growing wild in Tunisia (Silybum marianum L.)

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    The milk thistle plant grows in many regions in Tunisia; however, there is no literature regarding their oil composition. In this study, oil content, fatty acids and triacylglycerols compositions of milk thistle seeds growing wild in Tunisia were determined. The oil content was 30.5%, thus milk thistle seeds could be exploited as natural new source of oil. Among the fatty acids, linoleic acid had the highest percentage (59.98%) followed by oleic acid (21.26%) and palmitic acid (12.74%). The extracted oil from milk thistle seeds is rich in polyunsaturated fatty acids (60.37%). Various molecular species of TAGs were detected and the major forms were LLL (22.30%), OLL (20.40%), PLL (17.31%), POL (14.30%), and OOL (7.90%). It can be concluded that milk thistle seed oil has a characteristic TAG pattern as compared with these elucidated for olive oil and soybean oil

    Bioactive Lipids, Antibacterial, Hypoglycaemic, and Antioxidant Potentials of Immature and Mature Vicia faba L. Seeds Cultivated in Tunisia

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    Both the immature and mature Vicia faba L. seeds are used for human consumption. However, there is a lack of information on the phytochemical composition and the potent biological properties of the immature seeds. The aim of the present study was to establish the profile of bioactive lipids as well as the antibacterial, antioxidant, and α-amylase and α-glucosidase inhibitory capacities of the immature and mature Vicia faba L. seeds. The studied petroleum ether extracts contain different bioactive compounds such as β-sitosterol, lupeol, β-amyrin, α-tocopherol, and γ-tocopherol. The extracts of the immature seeds exhibited higher antioxidant and antibacterial activities than those of mature ones. All tested extracts exerted higher inhibition on α-glucosidase than α-amylase. The immature seeds appeared as promising sources of natural antioxidants, antibacterial compounds, and α-amylase and α-glucosidase inhibitors. Thus, the immature Vicia faba L. seeds have a great potential as functional foods providing health beneficial properties

    Direct Measurement of the System-Environment Coupling as a Tool For Understanding Decoherence and Dynamical Decoupling

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    Decoherence is a major obstacle to any practical implementation of quantum information processing. One of the leading strategies to reduce decoherence is dynamical decoupling --- the use of an external field to average out the effect of the environment. The decoherence rate under any control field can be calculated if the spectrum of the coupling to the environment is known. We present a direct measurement of the bath coupling spectrum in an ensemble of optically trapped ultracold atoms, by applying a spectrally narrow-band control field. The measured spectrum follows a Lorentzian shape at low frequencies, but exhibits non-monotonic features at higher frequencies due to the oscillatory motion of the atoms in the trap. These features agree with our analytical models and numerical Monte-Carlo simulations of the collisional bath. From the inferred bath-coupling spectrum, we predict the performance of well-known dynamical decoupling sequences: CPMG, UDD and CDD. We then apply these sequences in experiment and compare the results to predictions, finding good agreement in the weak-coupling limit. Thus, our work establishes experimentally the validity of the overlap integral formalism, and is an important step towards the implementation of an optimal dynamical decoupling sequence for a given measured bath spectrum.Comment: 9 pages, 6 figure

    Radical radiotherapy for paediatric solid tumour metastases:An overview of current European protocols and outcomes of a SIOPE multicenter survey

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    Purpose/objective: About 20% of children with solid tumours (ST) present with distant metastases (DM). Evidence regarding the use of radical radiotherapy of these DM is sparse and open for personal interpretation. The aim of this survey was to review European protocols and to map current practice regarding the irradiation of DM across SIOPE-affiliated countries. Materials/methods: Radiotherapy guidelines for metastatic sites (bone, brain, distant lymph nodes, lung and liver) in eight European protocols for rhabdomyosarcoma, non-rhabdomyosarcoma soft-tissue sarcoma, Ewing sarcoma, neuroblastoma and renal tumours were reviewed. SIOPE centres irradiating >= 50 children annually were invited to participate in an online survey. Results: Radiotherapy to at least one metastatic site was recommended in all protocols, except for high-risk neuroblastoma. Per protocol, dose prescription varied per site, and information on delineation and treatment planning/delivery was generally missing. Between July and September 2019, 20/27 centres completed the survey. Around 14% of patients were deemed to have DM from ST at diagnosis, of which half were treated with curative intent. A clear cut-off for a maximum number of DM was not used in half of the centres. Regardless of the tumour type and site, conventional radiotherapy regimens were most commonly used to treat DM. When stereotactic radiotherapy was used, a wide range of fractionation regimens were applied. Conclusion: Current radiotherapy guidelines for DM do not allow a consistent approach in a multicentre setting. Prospective (randomised) trials are needed to define the role of radical irradiation of DM from paediatric ST. (C) 2020 The Author(s). Published by Elsevier Ltd

    Cardiovascular effects of sub-daily levels of ambient fine particles: a systematic review

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    <p>Abstract</p> <p>Background</p> <p>While the effects of daily fine particulate exposure (PM) have been well reviewed, the epidemiological and physiological evidence of cardiovascular effects associated to sub-daily exposures has not. We performed a theoretical model-driven systematic non-meta-analytical literature review to document the association between PM sub-daily exposures (≤6 hours) and arrhythmia, ischemia and myocardial infarction (MI) as well as the likely mechanisms by which sub-daily PM exposures might induce these acute cardiovascular effects. This review was motivated by the assessment of the risk of exposure to elevated sub-daily levels of PM during fireworks displays.</p> <p>Methods</p> <p>Medline and Elsevier's EMBase were consulted for the years 1996-2008. Search keywords covered potential cardiovascular effects, the pollutant of interest and the short duration of the exposure. Only epidemiological and experimental studies of adult humans (age > 18 yrs) published in English were reviewed. Information on design, population and PM exposure characteristics, and presence of an association with selected cardiovascular effects or physiological assessments was extracted from retrieved articles.</p> <p>Results</p> <p>Of 231 articles identified, 49 were reviewed. Of these, 17 addressed the relationship between sub-daily exposures to PM and cardiovascular effects: five assessed ST-segment depression indicating ischemia, eight assessed arrhythmia or fibrillation and five considered MI. Epidemiologic studies suggest that exposure to sub-daily levels of PM is associated with MI and ischemic events in the elderly. Epidemiological studies of sub-daily exposures suggest a plausible biological mechanism involving the autonomic nervous system while experimental studies suggest that vasomotor dysfunction may also relate to the occurrence of MI and ischemic events.</p> <p>Conclusions</p> <p>Future studies should clarify associations between cardiovascular effects of sub-daily PM exposure with PM size fraction and concurrent gaseous pollutant exposures. Experimental studies appear more promising for elucidating the physiological mechanisms, time courses and causes than epidemiological studies which employ central pollution monitors for measuring effects and for assessing their time course. Although further studies are needed to strengthen the evidence, given that exposure to sub-daily high levels of PM (for a few hours) is frequent and given the suggestive evidence that sub-daily PM exposures are associated with the occurrence of cardiovascular effects, we recommend that persons with cardiovascular diseases avoid such situations.</p

    First report of naturally infected Sergentomyia minuta with Leishmania major in Tunisia

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    International audienceBackground: Many sand fly species are implicated in the transmission cycle of Leishmania parasites around the world. Incriminating new sand flies species, as vectors of Leishmania is crucial to understanding the parasite-vector transmission cycle in different areas in Tunisia and surrounding countries. Findings: Seventy-four unfed females belonging to the genera Sergentomyia and Phlebotomus were collected in South Tunisia between June and November 2014, using sticky papers. PCR-RFLP (Restriction Fragment Length Polymorphism) analysis of the internal transcribed spacer 1 (ITS1) was used for Leishmania parasites detection and identification. Leishmania (L.) major (Yakimoff & Shokkor, 1914) was identified within two Sergentomyia (S.) minuta (Rondani, 1843) and one Phlebotomus papatasi (Scopoli, 1786). Conclusion: This is the first report of L. major identified from S. minuta in Tunisia. This novel finding enhances the understanding of the transmission cycle of L. major parasites of cutaneous leishmaniasis in an endemic area in South Tunisia

    Exposure to road traffic and railway noise and associations with blood pressure and self-reported hypertension: a cohort study

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    <p>Abstract</p> <p>Background</p> <p>Epidemiological studies suggest that long-term exposure to transport noise increases the risk for cardiovascular disorders. The effect of transport noise on blood pressure and hypertension is uncertain.</p> <p>Methods</p> <p>In 1993-1997, 57,053 participants aged 50-64 year were enrolled in a population-based cohort study. At enrolment, systolic and diastolic blood pressure was measured. Incident hypertension during a mean follow-up of 5.3 years was assessed by questionnaire. Residential long-term road traffic noise (L<sub>den</sub>) was estimated for 1- and 5-year periods preceding enrolment and preceding diagnosis of hypertension. Residential exposure to railway noise was estimated at enrolment. We conducted a cross-sectional analysis of associations between road traffic and railway noise and blood pressure at enrolment with linear regression, adjusting for long-term air pollution, meteorology and potential lifestyle confounders (N = 44,083). Incident self-reported hypertension was analyzed with Cox regression, adjusting for long-term air pollution and potential lifestyle confounders.</p> <p>Results</p> <p>We found a 0.26 mm Hg higher systolic blood pressure (95% confidence intervals (CI): -0.11; 0.63) per 10 dB(A) increase in 1-year mean road traffic noise levels, with stronger associations in men (0.59 mm Hg (CI: 0.13; 1.05) per 10 dB(A)) and older participants (0.65 mm Hg (0.08; 1.22) per 10 dB(A)). Road traffic noise was not associated with diastolic blood pressure or hypertension. Exposure to railway noise above 60 dB was associated with 8% higher risk for hypertension (95% CI: -2%; 19%, P = 0.11).</p> <p>Conclusions</p> <p>While exposure to road traffic noise was associated with systolic blood pressure in subgroups, we were not able to identify associations with hypertension.</p

    Dynamical decoupling and noise spectroscopy with a superconducting flux qubit

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    The characterization and mitigation of decoherence in natural and artificial two-level systems (qubits) is fundamental to quantum information science and its applications. Decoherence of a quantum superposition state arises from the interaction between the constituent system and the uncontrolled degrees of freedom in its environment. Within the standard Bloch-Redfield picture of two-level system dynamics, qubit decoherence is characterized by two rates: a longitudinal relaxation rate Gamma1 due to the exchange of energy with the environment, and a transverse relaxation rate Gamma2 = Gamma1/2 + Gamma_phi which contains the pure dephasing rate Gamma_phi. Irreversible energy relaxation can only be mitigated by reducing the amount of environmental noise, reducing the qubit's internal sensitivity to that noise, or through multi-qubit encoding and error correction protocols (which already presume ultra-low error rates). In contrast, dephasing is in principle reversible and can be refocused dynamically through the application of coherent control pulse methods. In this work we demonstrate how dynamical-decoupling techniques can moderate the dephasing effects of low-frequency noise on a superconducting qubit with energy-relaxation time T1 = 1/Gamma1 = 12 us. Using the CPMG sequence with up to 200 pi-pulses, we demonstrate a 50-fold improvement in the transverse relaxation time T2 over its baseline value. We observe relaxation-limited times T2(CPMG) = 23 us = 2 T1 resulting from CPMG-mediated Gaussian pure-dephasing times in apparent excess of 100 us. We leverage the filtering property of this sequence in conjunction with Rabi and energy relaxation measurements to facilitate the spectroscopy and reconstruction of the environmental noise power spectral density.Comment: 21 pages (incl. 11-page appendix); 4 (+7) figure
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