283 research outputs found

    Influence of extraction methods on the composition of essential oils of Achillea millefolium L. from Lithuania

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    In this study, flowering aerial parts of Achillea millefolium were used as a matrix for supercritical CO2 extraction (SFE) of volatile oil. The collected extracts were analyzed by GC-FID and GC-MS methods and their composition were compared with that of the essential oil isolated by hydrodistillation (HD). The composition of the essential oil obtained by hydrodistillation and SFE methods is widely different. Indeed, the SFE volatile oil had a pale yellow color whereas the HD oil had a blue color due to the presence of chamazulene (48.0% vs. 4.3%). Other important constituents of HD oil were (E)- caryophyllene (19.5 %) and γ-muurolene (13.1%). The CO2 supercritical extract was dominated by (E)-caryophyllene (26.0%), γ-muurolene (22.0%), and caryophyllene oxide (8.1%)

    Ethnopharmacobotany and diversity of Mediterranean endemic plants in Marmilla subregion, Sardinia, Italy

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    Human populations in various regions across the world exploit the medicinal properties of plants to treat a wide variety of diseases. Areas with both high rates of endemic taxa and persisting traditional uses of the local botanical resources are key sites for the investigation of Traditional Botanical Knowledge (TBK). Commonly, in these areas, information regarding the medicinal properties of native plants has been transmitted orally from generation to generation, however, a rapid decline in this knowledge has been observed, which can be attributed to socio-economic changes in recent years. The Mediterranean basin is one such site, where human history is intimately entwined with nature. The unique geographical situation and unrivaled environmental heterogeneity of the area, have allowed both the development of diverse civilizations as well as providing the basis for the evolution of extraordinary biodiversity. The Mediterranean basin can therefore be considered a global hotspot of endemic vascular plants, and of traditional knowledge of medicinal and aromatic species. This study researches the historical subregion of Marmilla (central-southern Sardinia, Italy), which was chosen because of its specific cultural and demographic characteristics: i.e., prolonged isolation and extreme longevity of the inhabitants of the area. Semi-structured interviews were conducted with 145 people from the region, and 137 medicinal plants belonging to 62 families were identified, of which around 57,3% were taxa exclusive to the Mediterranean Basin. Findings showed that the most used parts of the plant were the leaves (49%), while as far as preparations are concerned, decoction (50%) was the most used to prepare medicinal formulations, making this the highest number of medico-botanical taxa reported in a study carried out in Sardinia using a similar methodology. In addition, this study contributes towards preventing the loss of TBK by documenting the medicinal traditions, passed down orally for centuries, in the words of the participants, shedding new light on the traditional knowledge of the inhabitants of the island. The findings lay the foundations for future applied studies in the fields of phytotherapy and phytochemical investigation

    Study of impulsive stimulated raman scattering effects using the femtosecond pump–probe z-scan technique

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    Impulsive stimulated Raman scattering (ISRS) is a nonlinear pump–probe spectroscopy technique particularly suitable to study vibrational intermolecular and intramolecular modes in complex systems. For the latter, recent studies of ISRS microscopy with low-energy laser sources have attracted attention for investigation of photosensitive or biological samples. Following this stream of interest, in this paper, we report an investigation on the relationship between femtosecond ISRS data and pump–probe Z-scan measurements, showing that the latter technique is capable of capturing the Kerr nonlinearities induced by the molecular vibrational modes. To this aim, firstly, spectrally filtered and Raman-induced Kerr ISRS signals were simultaneously acquired to determine the sample nonlinear response and to establish the reference data for the Z-scan analysis. Then, by adopting a suitable experimental arrangement to avoid thermo-optical effects, we were able to unambiguously observe the Raman-induced effects in Z-scan measurements, thus obtaining a consistent picture between ISRS and Z-scan for the first time, to the best of our knowledge. Practical applications of the proposed method include calibrated measurements of the contribution of the internal (Raman) and external molecular modes to the nonlinear refractive index

    Toward Gas-Phase Thermometry Using Pure-Rotational Impulsive Stimulated Raman Scattering Spectroscopy with a Low-Energy Femtosecond Oscillator

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    Femtosecond coherent Raman techniques have significant diagnostic value for the sensitive and non-intrusive measurement of temperature, pressure, and composition of gas mixtures. Due to the low density of samples, however, such measurements make use of high-energy amplified laser sources, with unwieldy and costly experimental setups. In this paper, we demonstrate an experimental setup equipped with a low-energy and low-average-power femtosecond oscillator allowing measurement of the pure-rotational spectrum of nitrogen down to atmospheric pressure using impulsive stimulated Raman scattering. Using a simplified model to analyze the experimental data we were able to derive the gas temperature with reasonable accuracy

    Chemical composition, antibacterial and antioxidant activities of essential oils from flowers, leaves and aerial parts of Tunisian Dittrichia Viscosa

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    The objective of this work was to determine the chemical composition, the antioxidant and antibacterial activities of the essential oils (EOs) extracted by hydrodistillation from different organs of the D. viscosa: flowers, leaves and aerial parts. The main compounds identified by GC/MS are oxygenated sesquiterpenes. Among these compounds, (E)-nerolidol (40.7%) is the most abundant constituent of flowers’ essential oil while caryophyllene oxide (9.9%), isolongifolan-7-α-ol (10.3%) and α -eudesmol (9.1%) are the major constituents of the leaves’ essential oil. The presence of these compounds in the aerial parts’ essential oil is solely due to those of the flowers and leaves that constitute these aerial parts. The volatile extracts showed antioxidant effects with IC50 values ranging between 9.25 and 9.75 mg.mL−1. On the other hand, EOs showed antibacterial effects on both Gram-positive and Gram-negative bacteria. The highest activity was obtained with flowers’ essential oil against Enterococcus faecalis and Escherichia coli

    Burnout, well-being and defensive medical practice among obstetricians and gynaecologists in the UK: cross-sectional survey study

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    Objectives: To determine the prevalence of burnout in doctors practising obstetrics and gynaecology, and assess the association with defensive medical practice and self-reported wellbeing. Design: Nationwide online cross-sectional survey study; December 2017-March 2018. Setting: Hospitals in the United Kingdom Participants: 5661 practising Obstetrics and Gynaecology consultants, specialty and associate specialist doctors and trainees registered with the Royal College of Obstetricians and Gynaecologists Primary and Secondary Outcome Measures: Prevalence of burnout using the Maslach Burnout Inventory and defensive medical practice (avoiding cases or procedures, overprescribing, over-referral) using a 12-item questionnaire. The odds ratios of burnout with defensive medical practice and self-reported wellbeing. Results: 3102/5661 doctors (55%) completed the survey. 3073/3102 (99%) met the inclusion criteria (1462 consultants, 1357 trainees and 254 specialty and associate specialist doctors). 1116/3073 (36%) doctors met the burnout criteria, with levels highest amongst trainees (580/1357 [43%]). 258/1116 (23%) doctors with burnout reported increased defensive practice compared to 142/1957 (7%) without (adjusted odds ratio 4.35, 95% CI 3.46 to 5.49). Odds ratios of burnout with wellbeing items varied between 1.38 and 6.37, and were highest for anxiety (3.59, 95% CI 3.07 to 4.21), depression (4.05, 95% CI 3.26 to 5.04), and suicidal thoughts (6.37, 95% CI 95% CI 3.95 to 10.7). In multivariable logistic regression, being of younger age, white or ‘other’ ethnicity, and graduating with a medical degree from the UK or Ireland had the strongest associations with burnout. Conclusions: High levels of burnout were observed in obstetricians and gynaecologists and particularly amongst trainees. Burnout was associated with both increased defensive medical practice and worse doctor wellbeing. These findings have implications for the wellbeing and retention of doctors as well as the quality of patient care, and may help to inform the content of future interventions aimed at preventing burnout and improving patient safety

    Chemical composition and biological activity of essential oil of Teucrium scordium L. subsp. scordioides (Schreb.) Arcang. (Lamiaceae) from Sardinia Island (Italy)

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    The aim of this study is to demonstrate the antifungal, anti-inflammatory and anti-migratory potential of the essential oil of Teucrium scordium subsp. scordioides (Schreb.) Arcang, a plant widely used in traditional medicine in Sardinia. The oil was rich in germacrene D (25.1%), δ-cadinene (12.9%) and alloaromadendrene (11.3%). The yeast Cryptococcus neoformans and the dermatophytes Trichophyton rubrum, T. mentagrophytes var. interdigitale and Epidermophyton floccosum were the most susceptible fungi to the action of the oil. In lipopolysaccharide (LPS)-stimulated macrophages, the oil was able to decrease nitric oxide production by ca. 30% at 1.25 μL/mL, without affecting cell viability. In the scratch wound assay, it allowed for ca. 36% of wound closure after 18 h, thus showing anti-migratory properties. Overall, this study highlights the potential of this species to mitigate fungal infections associated with an inflammatory response. Furthermore, we also reported for the first time its anti-migratory capacity, thus suggesting anticancer properties

    Tropospheric and ionospheric anomalies induced by volcanic and saharan dust events as part of geosphere interaction phenomena

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    In this work, we assessed the possible relation of ionospheric perturbations observed by Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions (DEMETER), Global Positioning System total electron content (GPS TEC), National Oceanic and Atmospheric Administration (NOAA)-derived outgoing longwave-Earth radiation (OLR), and atmospheric chemical potential (ACP) measurements, with volcanic and Saharan dust events identified by ground and satellite-based medium infrared/thermal infrared (MIR/TIR) observations. The results indicated that the Mt. Etna (Italy) volcanic activity of 2006 was probably responsible for the ionospheric perturbations revealed by DEMETER on 4 November and 6 December and by GPS TEC observations on 4 November and 12 December. This activity also affected the OLR (on 26 October; 6 and 23 November; and 2, 6, and 14 December) and ACP (on 31 October-1 November) analyses. Similarly, two massive Saharan dust episodes, detected by Robust Satellite Techniques (RST) using Spinning Enhanced Visible and Infrared Imager (SEVIRI) optical data, probably caused the ionospheric anomalies recorded, based on DEMETER and GPS TEC observations, over the Mediterranean basin in May 2008. The study confirmed the perturbing effects of volcanic and dust events on tropospheric and ionospheric parameters. Further, it demonstrated the advantages of using independent satellite observations to investigate atmospheric phenomena, which may not always be well documented. The impact of this increased detection capacity in reducing false positives, in the framework of a short-term seismic hazard forecast based on the study of ionospheric and tropospheric anomalies, is also addressed

    New insights on the antifungal activity of essential oil of Salvia desoleana Atzei et Picci, an endemic plant from folk medicine of Sardinia, Italy

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    757-760This work reports the results concerning the antifungal activity of the essential oil obtained from Salvia desoleana, an endemic plant from folk medicine of Sardinia Island, Italy. Chemical analysis of S. desoleana essential oil isolated by hydrodistillation was carried out by gas chromatography (GC-FID) and gas chromatography–mass spectrometry (GC-MS). The essential oil contains high amounts of oxygenated monoterpenes and sesquiterpene hydrocarbons, being linalyl acetate (21.0%), a-terpinyl acetate (17.3%), 1,8-cineole (6.7%), linalool (3.6%), sclareol (3.5%) and germacrene D (22.1%) the main compounds. The oil was more active against the yeast Cryptococcus neoformans and the dermatophyte Trichophyton rubrum with MIC values of 0.16 μL/mL and 0.32 μL/mL, respectively. The oil revealed an important inhibitory effect on the germ tube formation in C. albicans. It was able to achieve about 40% of inhibition of filamentation at concentrations as low as 0.08 µL/mL. These findings add significant information to the biological activity of the essential oil of S. desoleana, specifically to its antifungal properties, thus justifying and reinforcing the use of this plant in traditional medicine
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