1,556 research outputs found

    Longstanding Endobronchial Foreign Body

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    There are many circumstances in which the diagnosis of endobronchial inhalation of a foreign body (FB) can be missed. Generally, in such cases, within weeks or at most months from the event, clinical bronchopulmonary symptoms develop which allow a correct diagnosis to be made and significant complications to be avoided. We report the case of a patient in whom an endobronchial FB remained undiagnosed, because of lack of symptoms, for almost three years, and then caused signifiicant complications before being identified and removed. Problems related to diagnosis and therapy are discussed

    Phospholipase A 2 Modulates Different Subtypes of Excitatory Amino Acid Receptors: Autoradiographic Evidence

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    Exogenous phospholipases have been used extensively as tools to study the role of membrane lipids in receptor mechanisms. We used in vitro quantitative autoradiography to evaluate the effect of phospholipase A 2 (PLA 2 ) on N -methyl-D-aspartate (NMDA) and non-NMDA glutamate receptors in rat brain. PLA 2 pretreatment induced a significant increase in Α-[ 3 H]amino-3-hydroxy-5-methylisoxazole-4-propionate ([ 3 H]AMPA) binding in the stratum radiatum of the CA1 region of the hippocampus and in the stratum moleculare of the cerebellum. No modification of [ 3 H]AMPA binding was found in the stratum pyramidale of the hippocampus at different ligand concentrations. [ 3 H]-Glutamate binding to the metabotropic glutamate receptor and the non-NMDA-, non-kainate-, non-quisqualate-sensitive [ 3 H]glutamate binding site were also increased by PLA 2 pretreatment. [ 3 H]Kainate binding and NMDA-sensitive [ 3 H]glutamate binding were minimally affected by the enzyme pretreatment. The PLA 2 effect was reversed by EGTA, the PLA 2 inhibitor p -bromophenacyl bromide, and prolonged pretreatment with heat. Bovine serum albumin (1%) prevented the increase in metabotropic binding by PLA 2 . Arachidonic acid failed to mimic the PLA 2 effect on metabotropic binding. These results indicate that PLA 2 can selectively modulate certain subtypes of excitatory amino acid receptors. This effect is due to the enzymatic activity but is probably not correlated with the formation of arachidonic acid metabolites. Independent of their possible physiological implications, our results provide the first autoradiographic evidence that an enzymatic treatment can selectively affect the binding properties of excitatory amino acid receptors in different regions of the CNS.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66358/1/j.1471-4159.1993.tb05843.x.pd

    Bacterial biofilms on biopolymeric sorbent supports for environmental bioremediation

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    Bioremediation encompasses a broad range of environmental biotechnology, which require multidisciplinary approaches through implementation of innovative tools to the natural biological process occurring in soil, water and air. Immobilization of hydrocarbon-degrading microorganisms on biodegradable sorbent supports significantly promotes bioremediation processes. Recently ecofriendly, low cost bioremediation devices based on polylactic acid (PLA) and polycaprolactone (PCL) membranes hosting a biodegrading bacterial biofilms were obtained[1]. This work investigates the higher effectiveness of immobilizing hydrocarbon-degrading bacteria compared to that of planktonic cells. Soil hydrocarbon (HC) degrading Actinobacteria Nocardia cyriacigeorgica strain SoB, Gordonia amicalis strain SoCg[2], and the marine hydrocarbonoclastic Alcanivorax borkumensis strain AU3-AA-7[3] were immobilized on PLA and PCL membranes and tested on hexadecane. The capacity of adhesion and proliferation of these biodegrading biofilms within the biopolymers were evaluated at various time points (5, 10, 15, and 30 incubation days) using scanning electron microscopy (SEM). The SEM images revealed that PLA and PCL nanofibers were nearly completely covered by a complex three-dimensional bacterial film for all tested strains. Quantification of total biomass (estimated as total dsDNA) confirmed biofilm growth up to 30 days of incubation. Crude oil biodegradation ability of biofilms-membranes systems, assessed by Gas Chromatography-FID analysis, demonstrated the removal of over 60% of the oil after 5 days of incubation, outperforming free-living bacteria by 24%. Viable plate counts showed that bacterial biofilms adsorbed on biopolymers were still viable after 30 days, indicating their potential for long-term applications

    Are Botanical Biopesticides Safe for Bees (Hymenoptera, Apoidea)?

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    The recent global decline in insect populations is of particular concern for pollinators. Wild and managed bees (Hymenoptera, Apoidea) are of primary environmental and economic importance because of their role in pollinating cultivated and wild plants, and synthetic pesticides are among the major factors contributing to their decline. Botanical biopesticides may be a viable alternative to synthetic pesticides in plant defence due to their high selectivity and short environmental persistence. In recent years, scientific progress has been made to improve the development and effectiveness of these products. However, knowledge regarding their adverse effects on the environment and non-target species is still scarce, especially when compared to that of synthetic products. Here, we summarize the studies concerning the toxicity of botanical biopesticides on the different groups of social and solitary bees. We highlight the lethal and sublethal effects of these products on bees, the lack of a uniform protocol to assess the risks of biopesticides on pollinators, and the scarcity of studies on specific groups of bees, such as the large and diverse group of solitary bees. Results show that botanical biopesticides cause lethal effects and a large number of sublethal effects on bees. However, the toxicity is limited when comparing the effects of these compounds with those of synthetic compounds

    A natural histone H2A variant lacking the Bub1 phosphorylation site and regulated depletion of centromeric histone CENP-A foster evolvability in Candida albicans.

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    Eukaryotes have evolved elaborate mechanisms to ensure that chromosomes segregate with high fidelity during mitosis and meiosis, and yet specific aneuploidies can be adaptive during environmental stress. Here, we identify a chromatin-based system required for inducible aneuploidy in a human pathogen. Candida albicans utilizes chromosome missegregation to acquire tolerance to antifungal drugs and for nonmeiotic ploidy reduction after mating. We discovered that the ancestor of C. albicans and 2 related pathogens evolved a variant of histone 2A (H2A) that lacks the conserved phosphorylation site for kinetochore-associated Bub1 kinase, a key regulator of chromosome segregation. Using engineered strains, we show that the relative gene dosage of this variant versus canonical H2A controls the fidelity of chromosome segregation and the rate of acquisition of tolerance to antifungal drugs via aneuploidy. Furthermore, whole-genome chromatin precipitation analysis reveals that Centromere Protein A/ Centromeric Histone H3-like Protein (CENP-A/Cse4), a centromeric histone H3 variant that forms the platform of the eukaryotic kinetochore, is depleted from tetraploid-mating products relative to diploid parents and is virtually eliminated from cells exposed to aneuploidy-promoting cues. We conclude that genetically programmed and environmentally induced changes in chromatin can confer the capacity for enhanced evolvability via chromosome missegregation

    Explainable Persuasion in Interactive Design

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    Persuasive technology refers to the use of digital means to influence attitude, behaviour, and decisions. While a professional design of persuasive interfaces shall consider user interests and freedom of choice as a primary requirement, principles, and methods to achieve it are yet to be introduced. In the design of persuasive interfaces, fulfilling conditions of informed consent can help establish transparency and resolve such ethical issues. This paper introduces the concept of explainable persuasion as a way to address informed consent within persuasive interfaces. We provide a definition for explainable persuasion, highlight the need for it, discuss the design approach and underline the challenges to be addressed when designing explainable persuasive interfaces

    Heat Sources within the Greenland Ice Sheet: Dissipation, Temperate Paleo-Firn and Cryo-Hydrologic Warming

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    Ice temperature profiles from the Greenland Ice Sheet contain information on the deformation history, past climates and recent warming. We present full-depth temperature profiles from two drill sites on a flow line passing through Swiss Camp, West Greenland. Numerical modeling reveals that ice temperatures are considerably higher than would be expected from heat diffusion and dissipation alone. The possible causes for this extra heat are evaluated using a Lagrangian heat flow model. The model results reveal that the observations can be explained with a combination of different processes: enhanced dissipation (strain heating) in ice-age ice, temperate paleo-firn, and cryo-hydrologic warming in deep crevasses

    Toll-like receptor kinetics in septic shock patients: a preliminary study.

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    The aim of this study is to evaluate some inflammatory parameter changes in septic shock patients and their possible correlation with clinical outcome, in particular when continuous veno-venous hemofiltration (CVVH) treatment is required. Considering the objective difficulty in enrolling this kind of patient, a preliminary study was initiated on seventeen septic shock patients admitted to a medical and surgical ICU. The mRNA expression of Toll-like receptor (TLR)-1, TLR-2, TLR-4, TLR-5, TLR-9, TNFalpha, IL-8 and IL-1beta was assessed, the plasmatic concentrations of IL-18, IL-2, IL-10 and TNFalpha were measured on the day of sepsis diagnosis and after 72 h. In those patients who developed acute renal failure unresponsive to medical treatment and who underwent CVVH treatment the same parameters were measured every 24 h during CVVH and after completion of the treatment. On sepsis diagnosis, gene expression of TLRs was up-regulated compared to the housekeeping gene in all the patients. After 72 h, in 35% of the patients a down-regulation of these genes was found compared to day 1, but it was not associated with a reduction of cytokine serum levels or improved clinical signs, better outcome or reduced mortality. After high volume hemofiltration treatment, cytokine serum levels and TLR expression were not significantly modified. In conclusion, considering the not numerous number of cases, from our preliminary study, we cannot certainly correlate TLR over-expression in septic shock patients with severity or outcome scores
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