1,359 research outputs found

    The essential oil of Thymbra capitata and its application as a biocide on stone and derived surfaces

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    Many chemicals used nowadays for the preservation of cultural heritage pose a risk to both human health and the environment. Thus, it is desirable to find new and eco-friendly biocides that can replace the synthetic ones. In this regard, plant essential oils represent effective alternatives to synthetic substances for the preservation of historical monuments. Thymbra capitata (syn. Thymus capitatus) is a medicinal and aromatic plant growing in the Mediterranean area and endowed with important pharmacological properties related to its essential oil. Among them, the antimicrobial ones make the T. capitata essential oil an ideal candidate for industrial applications; for instance, as biocide for the inhibition and elimination of biological patinas of cyanobacteria and green algae on historical monuments. In the present work, we studied the chemical composition of the essential oil from T. capitata growing in Malta by gas chromatography-mass spectrometry (GC/MS). The major volatile component is the phenolic monoterpene carvacrol (73.2%), which is capable of damaging the cytoplasmic membrane and to interfere both in the growth curve and in the invasive capacity, though the contribution of minor components γ-terpinene and p-cymene cannot be disregarded. For the oil application on the stone surface, Pickering emulsions systems were prepared with an essential oil/water 1:3 mass ratio stabilized with kaolinite at 4 mass% in the presence of Laponite®; this allowed to limit the fast volatility of the oil and guaranteed a better application and an easier removal from the artefacts attacked by biodeteriogens both indoor and outdoor. This formulation caused the elimination of biodeteriogens from treated surfaces without residuals or films on artworks surface, and the effect was retained up to four months

    Identification of nitric oxide synthase in human and bovine oviduct

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    Nitric oxide synthase (NOS) is responsible for the biological production of nitric oxide (NO) in several organs. NOS activity has also been localized in the reproductive tract, although direct evidence for its presence in the human or bovine oviduct is still lacking. In the present study, four different techniques were used to identify the presence of NOS activity in human (n = 11) and bovine (n = 9) oviduct: (i) conversion of [3H]-L-arginine to [3H]-L-citrulline; (ii) production of nitrite/nitrate (NO2/NO3; stable NO metabolites); (iii) identification of NADPH-diaphorase activity; and (iv) immunostaining with antiserum to endothelial NOS. Cytosolic extracts from human ampullary segments of the Fallopian tube, obtained from post-partum patients (n = 4), converted [3H]-L-arginine to [3H]-L-citrulline (21.0 ± 8.8 fmol/mg protein/min). This conversion rate was significantly (P <0.05) reduced in the presence of either EDTA or N-monomethyl-L-arginine monoacetate (L-NMMA), an inhibitor of NOS activity. When bovine (n = 3) ampullary segments were incubated for 36 h in Hanks' balanced salt solution, the concentration of NO2/NO3 in the medium was increased (P <0.05) if segments were pretreated with lipopolysaccharide (LPS; an inducer of inducible NOS), but not after treatment with LPS + L-NMMA. Additionally, epithelial cells cultured from ampullary segments showed positive staining both for NADPH-diaphorase activity and with antiserum to endothelial NOS. The results of the present study provide direct evidence for the presence of both the Ca2+ -dependent constitutive form of NOS, as well as the inducible form of NOS activity in human and bovine oviduct. Since the oviduct plays a key role in the reproductive process, it is possible that the two forms of NOS may be involved in the physiological regulation of oviduct functio

    Endocrinology: Nuclear maturity and oocyte morphology after stimulation with highly purified follicle stimulating hormone compared to human menopausal gonadotrophin

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    Several studies have shown that high concentrations of luteinizing hormone (LH) in the follicular phase of stimulation can have a negative effect on oocyte quality, pregnancy rate and incidence of miscarriage. The aim of the present study was to examine the effects of highly purified follicle stimulating hormone (FSH HP) on ovarian stimulation and particularly on nuclear maturity and morphological appearance of the oocyte in intracytoplasmic sperm injection (ICSI) therapy and to compare the results with human menopausal gonadotrophin (HMG) stimulation. For this purpose, 50 patients for ICSI (HMG: 30; FSH HP: 20) and 26 patients for in-vitro fertilization (TVF; HMG: 14, FSH HP: 12) were stimulated with either HMG of FSH HP using a short-term protocol. Patients were divided into the two groups according to the first letter of their family name. No differences were observed among the groups in relation to patient age, duration of stimulation, number of aspirated oocytes or maturity of the oocyte-cumulus complex. After removal of the cumulus-corona cells in the ICSI oocytes, a significantly higher proportion of oocytes in the FSH HP group were nuclear mature (metaphase II) than in the HMG group (FSH HP: 88.8%, HMG: 80.6%; P = 0.009). Furthermore, in the FSH HP group, significantly fewer oocytes with dark cytoplasm were observed (FSH HP: 14.4%, HMG: 22.4%; P = 0.02). Fertilization, cleavage and pregnancy rates (FSH HP 38%, HMG: 34% per retrieval) were comparable in both groups. Based on the results obtained, it can be concluded that the short-term FSH HP treatment protocol synchronizes oocyte maturation better than comparable stimulation with HM

    Cambridge as a place in economics

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    Cambridge as a geographical reference often crops up in the characterisation of the economic theories and approaches that developed in Cambridge (UK) between the 1920s and the 1960s with the contribution of economists who did not always share the same interests, background or attitudes, but who all lived and worked – for considerable periods of time – in that particular corner of the world. In order to reconstruct the Cambridge of those years and explore the space it represented for economics we have selected a group of economists and a span of time – essentially between the two wars, with a few encroachments in the years following on the death of Keynes. Cambridge was not only a place, but also a play of magnetic forces, drawing together and driving apart, where ideas emerged from an environment formed through intense human and professional relations, a well defined cultural tradition and a way of its own of organising work and study. We present the dramatis personae and the background to their actions, and consider the characteristics of intellectual and personal communication on the basis of which we are led to define the Cambridge economists examined more as a `group' than a school

    Sesquiterpenoids in subtribe Centaureinae (Cass.) Dumort (tribe Cardueae, Asteraceae): distribution, 13C-NMR spectral data and biological properties

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    Asteraceae Bercht. & J. Presl is one of the biggest and most economically important plant families. The taxonomy and phylogeny of Asteraceae is rather complex and according to the latest and most reliable taxonomic classification of Panero & Funk, based on the analysis of nine chloroplast regions, the family is divided into 12 subfamilies and 35 tribes. One of the largest tribes of Asteraceae is Cardueae Cass. with four subtribes (Carlininae, Echinopinae, Carduinae and Centaureinae) and more than 2500 species. Susanna & Garcia-Jacas have organized the genera of Centaureinae (about 800 species) into seven informal groups, which recent molecular studies have confirmed: 1. Basal genera; 2. Volutaria group; 3. Rhaponticum group; 4. Serratula group; 5. Carthamus group; 6. Crocodylium group; 7. Centaurea group. This review summarizes reports on sesquiterpenoids from the Centaureinae subtribe of the Asteraceae family, as well as the 13C NMR spectral data described in the literature. It further reviews studies concerning the biological activities of these metabolites. For this work, literature data on sesquiterpenes from the Centaureinae subtribe were retrieved with the help of the SciFinder database and other similar data banks. All entries from 1958 until the end of 2011 were considered. This review is addressed to scientists working in the metabolomics field such as chemists, botanists, etc., the spectroscopic data reported make this work a good tool for structural elucidation, the biological section gives useful information to those who wish to study the structure activity relationships

    Separation of diamagnetic and paramagnetic anisotropy by high-field, low-temperature torque measurements

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    The anisotropy of magnetic susceptibility (AMS) of rocks can be composed of contributions from ferromagnetic, paramagnetic and diamagnetic minerals. However, in general the AMS of only one fraction is of interest. While there are several approaches to isolate the ferromagnetic contribution to the AMS, the separation of the diamagnetic from the paramagnetic contribution is still problematic. A new method for the separation of these two contributions based on high-field torque measurements at room and low-temperature is presented. The paramagnetic anisotropy increases at low temperature according to the Curie-Weiss law, whereas the diamagnetic contribution is temperature independent. If the paramagnetic AMS is due to perfectly oblate or prolate minerals and the ratio of the susceptibility differences at two temperatures is known, paramagnetic and diamagnetic AMS can be separated. When measuring in fields high enough to saturate the ferromagnetic phases all three contributions to the AMS can be separated. The separation of paramagnetic and diamagnetic AMS is demonstrated on natural crystals and synthetic calcite-muscovite aggregates. A high-field torque magnetometer, equipped with a cryostat for measurements at 77 K, allows sensitive measurements at two different temperatures. The sensitivity at 77 K is 3 × 10−7 J and standard-sized (palaeomagnetic) samples of 11.4 cm3 can be measured. This new method is especially suited for the investigation of diamagnetic fabrics of impure carbonate rock

    Modification in CSF specific gravity in acutely decompensated cirrhosis and acute on chronic liver failure independent of encephalopathy, evidences for an early blood-CSF barrier dysfunction in cirrhosis

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    Although hepatic encephalopathy (HE) on the background of acute on chronic liver failure (ACLF) is associated with high mortality rates, it is unknown whether this is due to increased blood-brain barrier permeability. Specific gravity of cerebrospinal fluid measured by CT is able to estimate blood-cerebrospinal fluid-barrier permeability. This study aimed to assess cerebrospinal fluid specific gravity in acutely decompensated cirrhosis and to compare it in patients with or without ACLF and with or without hepatic encephalopathy. We identified all the patients admitted for acute decompensation of cirrhosis who underwent a brain CT-scan. Those patients could present acute decompensation with or without ACLF. The presence of hepatic encephalopathy was noted. They were compared to a group of stable cirrhotic patients and healthy controls. Quantitative brain CT analysis used the Brainview software that gives the weight, the volume and the specific gravity of each determined brain regions. Results are given as median and interquartile ranges and as relative variation compared to the control/baseline group. 36 patients presented an acute decompensation of cirrhosis. Among them, 25 presented with ACLF and 11 without ACLF; 20 presented with hepatic encephalopathy grade ≥ 2. They were compared to 31 stable cirrhosis patients and 61 healthy controls. Cirrhotic patients had increased cerebrospinal fluid specific gravity (CSF-SG) compared to healthy controls (+0.4 %, p < 0.0001). Cirrhotic patients with ACLF have decreased CSF-SG as compared to cirrhotic patients without ACLF (−0.2 %, p = 0.0030) that remained higher than in healthy controls. The presence of hepatic encephalopathy did not modify CSF-SG (−0.09 %, p = 0.1757). Specific gravity did not differ between different brain regions according to the presence or absence of either ACLF or HE. In patients with acute decompensation of cirrhosis, and those with ACLF, CSF specific gravity is modified compared to both stable cirrhotic patients and healthy controls. This pattern is observed even in the absence of hepatic encephalopathy suggesting that blood-CSF barrier impairment is manifest even in absence of overt hepatic encephalopathy

    Headspace Volatile Composition of the Flowers of Caralluma europaea N.E.Br. (Apocynaceae)

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    The volatile constituents of the flowers of Caralluma (Apteranthes) europaea (Guss.) N.E. Br. (Apocynaceae - Asclepiadoideae) from Lampedusa Island were analyzed by headspace method. The analyses allowed the identification and quantification of 41 compounds. The main components were, among the monoterpenoids, terpinolene (23.3%), a-terpinene (19.1%) and linalool (18.4%), whereas, among the carbonylic compounds the major constituents were heptanal (2.0%), octanoic acid (2.4%) and hexanoic acid (1.7%). It is worth to mention the presence of a nitrogen containing compound, indole (0.8%) and of a sulphur containing compound, dimethylsulphide (t). The compounds found in the flowers of C. europea have been compared with data available in the literature as regard to their odor, presence in other sapromyiophilous taxa, possible role as semiochemicals, and presence in decaying organ matter. 89.3% of total constituents have been described in other sapromyiophilous taxa. Some of the compounds are present in several type of decaying organic matter (excrements, body in decomposition, and spoiled fish, etc). Several volatiles found in C. europea flowers are used as semiochemicals in Hymenoptera, Coleoptera, Diptera, Lepidoptera and other insects. Sixteen volatiles, accounting for 32.4% of the total constituents, are described as attractants of some Diptera families with a biology linked to decaying organic matters. Our data thus confirm that C. europea floral bouquet falls within the sapromyiophilous pollination syndrome

    Cytotoxic effect of eudesmanolides isolated from flowers of Tanacetum vulgare ssp. siculum

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    A phytochemical analysis of the dichloromethane extract from the flowers of a subspecies of Tanacetum vulgare growing in Sicily was carried out. Five known sesquiterpene lactones with the eudesmane skeleton have been isolated and the cytotoxic activity of these compounds was tested in vitro on A549 (human lung carcinoma epithelial-like) and V79379A (Chinese hamster lung fibroblast-like) cells using the tetrazolium salt reduction (MTT) assay. All of tested compounds induced high time- and concentration-dependent cytotoxic effects
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