86,611 research outputs found

    Identification of TAGs in archaeological amorphous organic residues by core shell RP stationary phase HPLC and ESI-MS-QTOF detection

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    A method based on the use of a Poroshell 120 EC-C18 column (3.0. mm. ×. 50. mm, 2.7. μm) with a high resolution electrospray ionization-quadrupole-time of flight (ESI-Q-ToF) tandem mass spectrometer as detection system was optimized for the identification of triacylglycerols (TAGs) in complex archaeological residues.The best performances in chromatographic separation and Q-ToF detection sensitivity were reached by using a mixture of iPrOH/MeOH at a 0.6. mL/min flow rate. Triolein (OOO) was eluted in 12.30. min and the chromatographic resolution against tripalmitin (PPP) was 1.4. Very good limits of detection and quantification limits were also achieved (LOD. <. 0.03. μg/g LOQ. <. 0.10. μg/g).These achievements were compared with the results provided by traditional particle columns and with the results reported in the recent literature regarding TAGs analysis in archaeological residues. Thanks to the unprecedented chromatographic separation and detection sensitivity attained, it was possible for the first time to perform TAGs researches in archaeological residues and reference materials with a dataset containing more than 500 molecular formula

    Field trial for evaluating the effects on honeybees of corn sown using Cruiser® and Celest xl® treated seeds

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    A first field study was conducted to investigate the possible adverse effects that seeds dressed with neonicotinoid insecticides pose to honeybees during sowing. It was observed that in the exposure hives bee mortality increased on the day of sowing and that the number of foraging bees decreased the days after the sowing. The corn sowing posed a significant threat to honeybees, with thiamethoxam being the most probable toxic agent. A theoretical contact exposure was calculated for a bee when flying over the sown fields, revealing a dose of 9.2 ng bee(-1) close to the contact LD50 of thiamethoxam

    HPLC-APCI-MS analysis of triacylglycerols (TAGs) in historical pharmaceutical ointments from the eighteenth century

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    The lipid fractions of residues from historical pharmaceutical ointments were analysed by reversed-phase liquid chromatography coupled with atmospheric pressure chemical ionization and mass spectrometer detection. The residues were contained in a series of historical apothecary jars, dating from the eighteenth century and conserved at the "Aboca Museum" in Sansepolcro (Arezzo, Italy) and at the pharmacy of the "Real Cartuja de Valldemossa" in Palma de Majorca (Spain). The analytical protocol was set up using a comparative study based on the evaluation of triacylglycerol (TAG) compositions in raw natural lipid materials and in laboratory-reproduced ointments. These ointments were prepared following pharmaceutical recipes reported in historical treatises and used as reference materials. The reference materials were also subjected to stress treatments in order to evaluate the modification occurring in the TAG profiles as an effect of ageing. TAGs were successfully detected in the reproduced formulations even in mixtures of up to ten ingredients and after harsh degradative treatments, and also in real historical samples. No particular interferences were detected from other non-lipid ingredients of the formulations. The TAG compositions detected in the historical ointments indicated a predominant use of olive oil and pig adipose material as lipid ingredients. The detection of a high level of tristearine and myristyl-palmitoyl-stearyl glycerol in two of the samples suggested the presence of a fatty material of a different origin (maybe a ruminant). On the basis of the positional isomer ratio, sn-PPO/sn-POP, it was possible to hypothesize an exclusive use of pig fat in one sample. We also evaluated the application of principal component analysis of TAG profiles as an approach for the multivariate statistical comparison of the reference and historical ointments

    Multi analytical study on Khol residues from the ancient Egyptian city of Assiut

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    Multi-analytical chemical approaches are nowadays considered an important source of complementary information in archaeological functional studies. Here we report the results of an investigation carried out by means of liquid chromatography-mass-spectrometry (LC-MS), pyrolysis-gas chromatography-mass spectrometry (py-GC-MS) and Raman micro-spectroscopy (μRaman) applied onto residues sampled from ceramic vessels, found in the ancient cities of Assiut (Egypt, Middle Kingdom). These items, characterized by the typical conical shape of Kohl containers, represented an extraordinary opportunity to study, at the same time, well preserved archaeological records and the related contents. Thanks to the combined analysis, it was possible to hypothesize the original recipes adopted to prepare the ancient cosmetic. The profile of the fatty ingredients resulted congruent with the information collected by the archaeologist from the excavation site, regarding the culture and the ancient Egyptian practice of eye-painting. The analysis of the sedimentary material confirmed the provenance of the archaeological recor

    Dual spatial host-bacterial gene expression in Mycobacterium abscessus respiratory infections

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    Co-localization of spatial transcriptome information of host and pathogen can revolutionize our understanding of microbial pathogenesis. Here, we aimed to demonstrate that customized bacterial probes can be successfully used to identify host-pathogen interactions in formalin-fixed-paraffin-embedded (FFPE) tissues by probe-based spatial transcriptomics technology. We analyzed the spatial gene expression of bacterial transcripts with the host transcriptomic profile in murine lung tissue chronically infected with Mycobacterium abscessus embedded in agar beads. Customized mycobacterial probes were designed for the constitutively expressed rpoB gene (an RNA polymerase β subunit) and the virulence factor precursor lsr2, modulated by oxidative stress. We found a correlation between the rpoB expression, bacterial abundance in the airways, and an increased expression of lsr2 virulence factor in lung tissue with high oxidative stress. Overall, we demonstrate the potential of dual bacterial and host gene expression assay in FFPE tissues, paving the way for the simultaneous detection of host and bacterial transcriptomes in pathological tissues

    Corrigendum: Screening of Host Specific Lactic Acid Bacteria Active Against Escherichia coli From Massive Sample Pools With a Combination of in vitro and ex vivo Methods

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    A Corrigendum on: Screening of Host Specific Lactic Acid Bacteria Active Against Escherichia Coli From Massive Sample Pools With a Combination of in vitro and ex vivo Methods by Ren, H., Saliu, E.-M., Zentek, J., Goodarzi Boroojeni, F., and Vahjen, W. (2019). Front. Microbiol. 10:2705. doi: 10.3389/fmicb.2019.02705 In the original article, there was a mistake in Figure 3 as published. The authors reversed the order of Figures 3A,B by mistake when uploading the figures. The corrected figure appears below

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Omega-3 rich oils from microalgae: A chitosan mediated in situ transesterification method

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    Microalgae are a precious source of polyunsaturated fatty acids (PUFA), however extraction is difficult due to the peculiar microalgae cell structure. Here we describe a new method based on the application of chitosan nanoaggregates as CO2 responsive emulsifier, used to promote the swelling of algae cell wall and the formation of a large oil – ethanol interphase area during the ethanolysis. Tests were carried out with Pseudokirchneriella subcapitata and Nannochloropsis sp. at different biomass/ethanol/chitosan ratios. CO2 was added to trigger demulsification to promote an easy recovery of the lipid fraction. The highest yields in PUFA were obtained with Nannochloropsis sp. (207.9 mg/g of oil) using 0.4% wt of chitosan and 1:10 biomass:ethanol ratio; 43.6 mg/g of linolenic acid were obtained from Pseudokirchneriella subcapitata. Overall, because the method employs ethanol, a generally recognized as safe (GRAS) solvent, and food grade additives, it is suited for the preparation of PUFA supplements

    [Newspaper Clipping: Author Claims Evidence of Second JFK Assassin #1]

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    Newspaper article titled "Author Claims Evidence of Second JFK Assassin." The article states that author Richard J. Whalen concluded "that there is circumstantial evidence to support the theory of a second assassin in the shooting of President John F. Kennedy.
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