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891.
Diana Poli Andrea Caglieri Matteo Goldoni Anna F. Castoldi Teresa Coccini Elisa Roda Annabella Vitalone Sandra Ceccatelli Antonio Mutti 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2009,877(8-9):773-783
A simple and reliable solid phase microextraction/gas chromatography–mass spectrometry (SPME/GC–MS) method was developed for the single-step determination of PCBs 126 and 153 in rat brain and serum, using liquid/liquid and solid phase extraction (SPE) as reference techniques. The multi-factor categorical experimental design used to study simultaneously the main parameters and their interactions affecting the efficiency of the method, showed that the use of an 85 μm PA exposed at 100 °C for 40 min was the optimum sampling condition for both PCBs. SPME was then validated by studying its linear dynamic (over two orders of magnitude), limits of detection (brain: 2 ng/g, serum: 0.2 ng/g) and analytical precision that was within 9% for SPME in both brain and serum. Finally, the method was used to determine the brain and blood target dose in mothers and pups after oral exposure of the mothers. 相似文献
892.
David Giraldi Mattia de’Michieli Vitturi Mattia Zaramella Andrea Marion Renato Iannelli 《Ecological Engineering》2009,35(2):265-273
Typical unsteady unsaturated conditions can profoundly affect the hydrodynamics of vertical subsurface flow constructed wetlands. In this study we analyzed the hydrodynamics of a 33 m2 vertical flow pilot plant, treating municipal secondary effluents. Three different saturation conditions were analyzed under several constant flux regimes: complete saturation, partial saturation with the free water table 20 cm over the bottom of the bed, and complete drainage. Tracer tests were performed in steady state conditions by dosing rhodamine WT as square input signals. Breakthrough curves were analyzed by means of both a classical residence time distribution analysis and an originally developed numerical plug-flow model with longitudinal dispersion adapted to the unsaturated conditions. We found that the degree of global mixing in the vertical flow constructed wetland increased as the water content increased; this effect was controlled by the hydraulic residence time of the system. Conversely, the degree of local mixing was inversely affected by water content; the dispersivity was 4.5, 10, and 14 cm for fully saturated, partially saturated and draining conditions, respectively. We explain the dependency of dispersivity on water content in physical terms; however, further studies are needed to mathematically include this relationship in numerical models that describe the behaviour of vertical flow constructed wetlands. 相似文献
893.
Sara Alberghini Elisa Polone Viviana Corich Milena Carlot Flavio Seno Antonio Trovato & Andrea Squartini 《FEMS microbiology letters》2009,292(2):149-161
Cell-to-cell bacterial communication via diffusible signals is addressed and the conceptual framework in which quorum sensing is usually described is evaluated. By applying equations ruling the physical diffusion of the autoinducer molecules, one can calculate the gradient profiles that would occur either around a single cell or at the center of volumes of increasing size and increasing cell densities. Water-based matrices at 25 °C and viscous biofilms at colder temperatures are compared. Some basic consequences relevant for the field of microbial signalling arise. As regards induction, gradient-mixing dynamics between as little as two cells lying at a short distance appears to be sufficient for the buildup of a concentration reaching the known thresholds for quorum sensing. A straight line in which the highest concentrations occur is also created as a consequence of the gradient overlap geometry, providing an additional signal information potentially useful for chemotactic responses. In terms of whole population signalling, it is shown how the concentration perceived by a cell in the center is critically dependent not only on the cell density but also on the size of the biofilm itself. Tables and formulas for the practical prediction of N -acyl homoserine lactones concentrations at desired distances in different cell density biofilms are provided. 相似文献
894.
To better understand the mechanism(s) of leukocyte Ca(2+) signaling, we have studied the intracellular locations of two Ca(2+)-mobilizing receptors, the inositol 1,4,5-trisphosphate receptor and ryanodine receptor, by immunofluorescence microscopy. Our results show that localization differs not only between receptor classes within a cell, but among leukocyte types as well. We also illustrate the importance of preserving labile cellular filaments in maintaining cell integrity by fixation with the Safiejko-Mroczka and Bell protocol, because conventional fixation methods distort receptor patterns. We suggest that the observed differences influence intracellular Ca(2+) signaling. 相似文献
895.
Rafael Rodrigues Silva Rafael M. Mariante Andrea Alice Silva Ana Luiza Barbosa dos Santos Ester Roffê Helton Santiago Ricardo Tostes Gazzinelli Joseli Lannes-Vieira 《PloS one》2015,10(2)
The inflammatory cytokine interferon-gamma (IFNγ) is crucial for immunity against intracellular pathogens such as the protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease (CD). IFNγ is a pleiotropic cytokine which regulates activation of immune and non-immune cells; however, the effect of IFNγ in the central nervous system (CNS) and astrocytes during CD is unknown. Here we show that parasite persists in the CNS of C3H/He mice chronically infected with the Colombian T. cruzi strain despite the increased expression of IFNγ mRNA. Furthermore, most of the T. cruzi-bearing cells were astrocytes located near IFNγ+ cells. Surprisingly, in vitro experiments revealed that pretreatment with IFNγ promoted the infection of astrocytes by T. cruzi increasing uptake and proliferation of intracellular forms, despite inducing increased production of nitric oxide (NO). Importantly, the effect of IFNγ on T. cruzi uptake and growth is completely blocked by the anti-tumor necrosis factor (TNF) antibody Infliximab and partially blocked by the inhibitor of nitric oxide synthesis L-NAME. These data support that IFNγ fuels astrocyte infection by T. cruzi and critically implicate IFNγ-stimulated T. cruzi-infected astrocytes as sources of TNF and NO, which may contribute to parasite persistence and CNS pathology in CD. 相似文献
896.
Antonio Pacilli Olga Lamacchia Andrea Fontana Massimiliano Copetti Mauro Cignarelli Vincenzo Trischitta Salvatore De Cosmo 《PloS one》2015,10(4)
Background
To investigate prospectively the relationship between target values of glycated hemoglobin, blood pressure and LDL-cholesterol, as considered in a combined fashion, and all-cause mortality in patients with type 2 diabetes mellitus.Methods
Two cohorts of patients with type 2 diabetes mellitus, the Gargano Mortality Study (n=810) and the Foggia Mortality Study (n=929), were investigated. A weighted target risk score was built as a weight linear combination of the recommended targets reached by each patient.Results
In the Gargano Mortality Study and in the Foggia Mortality Study (mean follow up=7.4 and 5.5 years, respectively), 161 (19.9%) and 220 (23.7%) patients died, with an age and sex adjusted annual incidence rate of 2.1 and 2.8 per 100 person-years, respectively. In both study samples the weighted target risk score tended to be linearly associated with all-cause mortality (HR for one point increment=1.30, 95% CI: 1.11-1.53, p=0.001, and HR=1.08, 95% CI: 0.95-1.24, p=0.243, respectively). When the two cohorts were pooled and analyzed together, a clear association between weighted target risk score and all-cause mortality was observed (HR for one point increment=1.17, 95% CI:1.05-1.30, p=0.004). This counterintuitive association was no longer observable in a model including age, sex, body mass index, smoking habit, estimated glomerular filtration rate, albuminuria and anti-diabetic, anti-hypertensive and anti-dyslipidemic treatment as covariates (HR for one point increment=0.99, 95% CI: 0.87-1.12, p=0.852).Conclusions
In a real life clinical set of patients with type 2 diabetes mellitus, the combination of recommended target values of established cardiovascular risk factors is not associated with all-cause mortality. 相似文献897.
Ylenia Ingrasciotta Janet Sultana Francesco Giorgianni Andrea Fontana Antonio Santangelo Daniele Ugo Tari Domenico Santoro Vincenzo Arcoraci Margherita Perrotta Luisa Ibanez Gianluca Trifirò 《PloS one》2015,10(4)
Background
Non-steroidal anti-inflammatory agents (NSAIDs) are known to be associated with renal damage. No clear evidence exists regarding differential risk of chronic kidney disease (CKD), specifically, across various NSAIDs.Aim
The aim of this population-based case-control study was to evaluate the association between use of individual NSAIDs and risk of CKD in a general population of Southern Italy.Methods
A nested case-control study was carried out using the general practice Arianna database, identifying incident CKD patients as cases and matched controls from 2006 to 2011. The date of first CKD diagnosis was defined as the index date (ID). Conditional logistic regressions were performed to estimate the risk of CKD associated with NSAIDs by class and individual drugs as compared to non-use during different time windows (within one year, six or three months prior to ID), with the latter being defined as current users. Among current users, the effect of cumulative exposure to these drugs was evaluated.Results
Overall, 1,989 CKD cases and 7,906 matched controls were identified. A statistically significant increase in the risk of CKD was found for current users of oxicams (adjusted OR: 1.68; 95% CI: 1.15-2.44) and concerning individual compounds, for ketorolac (adj. OR: 2.54; 95% CI: 1.45-4.44), meloxicam (adj. OR: 1.98; 95% CI: 1.01-3.87) and piroxicam (adj. OR: 1.95; 95% CI: 1.19-3.21).Conclusions
The risk of CKD varies across individual NSAIDs. Increased risk has been found for ketorolac, which may precipitate subclinical CKD through acute renal damage, and long-term exposure to oxicams, especially meloxicam and piroxicam. 相似文献898.
Reinhold Scherer Josef Faller Elisabeth V. C. Friedrich Eloy Opisso Ursula Costa Andrea Kübler Gernot R. Müller-Putz 《PloS one》2015,10(5)
Brain-computer interfaces (BCIs) translate oscillatory electroencephalogram (EEG) patterns into action. Different mental activities modulate spontaneous EEG rhythms in various ways. Non-stationarity and inherent variability of EEG signals, however, make reliable recognition of modulated EEG patterns challenging. Able-bodied individuals who use a BCI for the first time achieve - on average - binary classification performance of about 75%. Performance in users with central nervous system (CNS) tissue damage is typically lower. User training generally enhances reliability of EEG pattern generation and thus also robustness of pattern recognition. In this study, we investigated the impact of mental tasks on binary classification performance in BCI users with central nervous system (CNS) tissue damage such as persons with stroke or spinal cord injury (SCI). Motor imagery (MI), that is the kinesthetic imagination of movement (e.g. squeezing a rubber ball with the right hand), is the "gold standard" and mainly used to modulate EEG patterns. Based on our recent results in able-bodied users, we hypothesized that pair-wise combination of "brain-teaser" (e.g. mental subtraction and mental word association) and "dynamic imagery" (e.g. hand and feet MI) tasks significantly increases classification performance of induced EEG patterns in the selected end-user group. Within-day (How stable is the classification within a day?) and between-day (How well does a model trained on day one perform on unseen data of day two?) analysis of variability of mental task pair classification in nine individuals confirmed the hypothesis. We found that the use of the classical MI task pair hand vs. feed leads to significantly lower classification accuracy - in average up to 15% less - in most users with stroke or SCI. User-specific selection of task pairs was again essential to enhance performance. We expect that the gained evidence will significantly contribute to make imagery-based BCI technology become accessible to a larger population of users including individuals with special needs due to CNS damage. 相似文献
899.
Elisa Damiani Erica Adrario Michele Maria Luchetti Claudia Scorcella Andrea Carsetti Nicoletta Mininno Silvia Pierantozzi Tiziana Principi Daniele Strovegli Rosella Bencivenga Armando Gabrielli Rocco Romano Paolo Pelaia Can Ince Abele Donati 《PloS one》2015,10(5)
BackgroundFree hemoglobin (fHb) may induce vasoconstriction by scavenging nitric oxide. It may increase in older blood units due to storage lesions. This study evaluated whether old red blood cell transfusion increases plasma fHb in sepsis and how the microvascular response may be affected.MethodsThis is a secondary analysis of a randomized study. Twenty adult septic patients received either fresh or old (<10 or >15 days storage, respectively) RBC transfusions. fHb was measured in RBC units and in the plasma before and 1 hour after transfusion. Simultaneously, the sublingual microcirculation was assessed with sidestream-dark field imaging. The perfused boundary region was calculated as an index of glycocalyx damage. Tissue oxygen saturation (StO2) and Hb index (THI) were measured with near-infrared spectroscopy and a vascular occlusion test was performed.ResultsSimilar fHb levels were found in the supernatant of fresh and old RBC units. Despite this, plasma fHb increased in the old RBC group after transfusion (from 0.125 [0.098–0.219] mg/mL to 0.238 [0.163–0.369] mg/mL, p = 0.006). The sublingual microcirculation was unaltered in both groups, while THI increased. The change in plasma fHb was inversely correlated with the changes in total vessel density (r = -0.57 [95% confidence interval -0.82, -0.16], p = 0.008), De Backer score (r = -0.63 [95% confidence interval -0.84, -0.25], p = 0.003) and THI (r = -0.72 [95% confidence interval -0.88, -0.39], p = 0.0003).ConclusionsOld RBC transfusion was associated with an increase in plasma fHb in septic patients. Increasing plasma fHb levels were associated with decreased microvascular density.
Trial Registration
ClinicalTrials.gov NCT01584999相似文献900.
Ann-Christin E. Brehler Wolfgang Hartmann Stefanie Wiebe Andrea Kerkhoff Christoph Schliemann Daniel Palmes Norbert Senninger Frank Lenze Hansjoerg Ullerich Wolfgang E. Berdel Torsten Kessler 《PloS one》2015,10(4)