750 research outputs found

    Quantification of myo-inositol hexakisphosphate in alkaline soil extracts by solution 31P NMR spectroscopy and spectral deconvolution

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    Inositol phosphates are the dominant class of organic phosphorus (P) compounds in most soils, but they are poorly understood because they are not easily identified in soil extracts. This study reports a relatively simple technique using solution 31P NMR spectroscopy and spectral deconvolution for the quantification of myo-inositol hexakisphosphate (phytic acid), the most abundant soil inositol phosphate, in alkaline soil extracts. An authentic myo-inositol hexakisphosphate standard added to a re-dissolved soil extract gave signals at 5.85, 4.92, 4.55, and 4.43 ppm in the ratio 1:2:2:1. Spectral deconvolution quantified these signals accurately (102 ± 4%) in solutions containing a mixture of model P compounds by resolving the envelope of signals in the orthophosphate monoester region. In NaOH-EDTA extracts from a range of lowland permanent pasture soils in England and Wales, concentrations of myo-inositol hexakisphosphate determined by spectral deconvolution ranged between 26 and 189 mg P kg- 1 soil, equivalent to between 11 and 35% of the extracted organic P. Concentrations were positively correlated with oxalate-extractable aluminum and iron but were not correlated with total carbon, total nitrogen, clay, or the microbial biomass. This suggests that myo-inositol hexakisphosphate accumulates in soils by mechanisms at least partially independent of those controlling organic matter stabilization and dynamics. Furthermore, myo-inositol hexakisphosphate concentrations were positively correlated with plant-available inorganic P and negatively correlated with the carbon-to-organic P ratio, suggesting that biological P availability may, in part, regulate myo-inositol hexakisphosphate concentrations in soils, perhaps because organisms capable of degrading this compound are favored in more P-limited environments. Solution 31P NMR spectroscopy and spectral deconvolution offers a relatively simple method of quantifying myo-inositol hexakisphosphate in soil extracts

    The phosphorus composition of temperate pasture soils determined by NaOH-EDTA extraction and solution 31P NMR spectroscopy

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    Information on the composition and dynamics of soil phosphorus (P) remains limited, but is integral to understanding soil biogeochemical cycles. We used solution 31P nuclear magnetic resonance (NMR) spectroscopy to characterise NaOH—EDTA extractable P in 29 permanent pasture soils from England and Wales (total carbon 29-80 g kg- 1 soil, clay 219-681 g kg- 1 soil, pH 4.4-6.8). Total P ranged between 376 and 1981 mg P kg- 1 soil, of which between 45 and 88% was extracted with NaOH—EDTA. The extracts were dominated by orthophosphate monoesters (29-60% extracted P) and inorganic orthophosphate (21-55% extracted P), with smaller concentrations of orthophosphate diesters (2-10% extracted P), pyrophosphate (1-7% extracted P), phosphonates (0 - 3% extracted P), and traces of polyphosphates. Orthophosphate diesters were subclassified into phospholipids (1- 7% extracted P) and DNA (1-6% extracted P). Signals slightly downfield of inorganic orthophosphate were tentatively assigned to aromatic orthophosphate diesters similar in structure to R-(—)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate. Such signals are rarely detected in soil extracts, but were present in relatively large concentrations in the samples analysed here (2-5% extracted P). Relationships between functional P groups and soil properties suggested that the various functional groups are involved in the soil P cycle to different extents. In particular, concentrations of orthophosphate monoesters appeared to be controlled by the potential for chemical stabilisation in soil, whereas DNA and pyrophosphate were strongly correlated with the microbial biomass, suggesting an active involvement in biological nutrient turnove

    Kleinhandel in Brussel: de stad verzoenen met een sector in volle verandering

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    In 2017 telde het Brussels Hoofdstedelijk Gewest 20 700 verkooppunten van goederen en diensten, via dewelke de Brusselaars 87 % van hun uitgaven besteden. De detailhandel vertegenwoordigt ongeveer 9 % van de werkgelegenheid in het gewest. Deze synthesenota geeft een overzicht van de kennis over de handel in Brussel, een essentiële economische sector die echter moeilijk te vatten is wegens de diversiteit. Bovendien wordt deze sector geconfronteerd met ingrijpende veranderingen in de consumptie, de stadsomgeving en de interne organisatie van het beroep. Na een toelichting van het analysekader, waarbij de handel wordt gedefinieerd aan de hand van de functies, vormen en spelers, komen de auteurs tot een aantal bevindingen die verband houden met belangrijke dynamieken in de sector (verandering van aanbod en vraag, ontwikkeling van de overheidsregulering...). Het derde deel van de nota biedt een antwoord hierop door te bepalen met welke grote uitdagingen de sector, met de steun van de overheid, rekening zal moeten houden om handel en stad weer met elkaar te kunnen verzoenen.La Région de Bruxelles-Capitale comptait en 2017 20 700 points de vente de biens et de services, par lesquels transitent 87 % des dépenses effectuées par les Bruxellois. Ce commerce de détail offre environ 9 % de l’emploi régional. Cette note de synthèse fait le point des connaissances sur la distribution à Bruxelles, un secteur économique indispensable, mais complexe à appréhender du fait de sa diversité et traversé par de profondes évolutions de la consommation, de l’environnement urbain et de l’organisation interne du métier. Après avoir esquissé le cadre de l’analyse en définissant le commerce au travers de ses fonctions, de ses formes et de ses acteurs, les auteurs dressent plusieurs constats associés à des dynamiques majeures du secteur (transformation de l’offre, de la demande et évolution de la régulation publique, notamment). La troisième partie de la note répond à ces constats par l’identification d’enjeux clairs dont la prise en compte par le secteur, soutenu par les autorités publiques, pourrait réconcilier le commerce et l’espace urbain.In 2017, the Brussels-Capital Region 20 700 points of sale for goods and services, accounting for 87 % of the expenditure made by the inhabitants of Brussels. This retail trade provides about 9 % of regional employment. This synopsis reviews what is known about distribution in Brussels, an indispensable economic sector whose complexity makes it difficult to understand due to its diversity, and which is subject to profound changes in consumption, the urban environment and the internal organisation of the profession. After outlining the framework of the analysis by defining trade through its functions, forms and stakeholders, the authors draw up several observations associated with major dynamics in the sector (transformation of supply and demand and changes in public regulation in particular). The third part of the synopsis responds to these observations by identifying clear issues which, if taken into account by the sector and supported by public authorities, could reconcile trade with urban space

    Anomalies of O3_3, CO, C2_2H2_2, H2_2CO, and C2_2H6_6 detected with multiple ground-based Fourier-transform infrared spectrometers and assessed with model simulation in 2020: COVID-19 lockdowns versus natural variability

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    Anomalies of tropospheric columns of ozone (O3_3), carbon monoxide (CO), acetylene (C2_2H2_2), formaldehyde (H2_2CO), and ethane (C2_2H6_6) are quantified during the 2020 stringent COVID-19 world-wide lockdown using multiple ground-based Fourier-transform infrared spectrometers covering urban and remote conditions. We applied an exponential smoothing forecasting approach to the data sets to estimate business-as-usual values for 2020, which are then contrasted with actual observations. The Community Atmosphere Model with chemistry (CAM-chem) is used to simulate the same gases using lockdown-adjusted and business-as-usual emissions. The role of meteorology, or natural variability, is assessed with additional CAM-chem simulations. The tropospheric column of O3_3 declined between March and May 2020 for most sites with a mean decrease of 9.2% ± 4.7%. Simulations reproduce these anomalies, especially under background conditions where natural variability explains up to 80% of the decline for sites in the Northern Hemisphere. While urban sites show a reduction between 1% and 12% in tropospheric CO, the remote sites do not show a significant change. Overall, CAM-chem simulations capture the magnitude of the anomalies and in many cases natural variability and lockdowns have opposite effects. We further used the long-term record of the Measurements of Pollution in the Troposphere (MOPITT) satellite instrument to capture global anomalies of CO. Reductions of CO vary highly across regions but North America and Europe registered lower values in March 2020. The absence of CO reduction in April and May, concomitant with reductions of anthropogenic emissions, is explained by a negative anomaly in the hydroxyl radical (OH) found with CAM-chem. The implications of these findings are discussed for methane (CH4_4), which shows a positive lifetime anomaly during the COVID-19 lockdown period. The fossil fuel combustion by-product tracer C2H2 shows a mean drop of 13.6% ± 8.3% in urban Northern Hemisphere sites due to the reduction in emissions and in some sites exacerbated by natural variability. For some sites with anthropogenic influence there is a decrease in C2_2H6_6. The simulations capture the anomalies but the main cause may be related to natural variability. H2_2CO declined during the stringent 2020 lockdown in all urban sites explained by reductions in emissions of precursors

    Early planned removal versus expectant management of peripherally inserted central catheters to prevent infection in newborn infants (Review)

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    BACKGROUND: Duration of use may be a modifiable risk factor for central venous catheter-associated bloodstream infection in newborn infants. Early planned removal of peripherally inserted central catheters (PICCs) is recommended as a strategy to reduce the incidence of infection and its associated morbidity and mortality. OBJECTIVES: To determine the effectiveness of early planned removal of PICCs (up to two weeks after insertion) compared to an expectant approach or a longer fixed duration in preventing bloodstream infection and other complications in newborn infants. SEARCH METHODS: We searched of the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 4), Ovid MEDLINE, Embase, Maternity & Infant Care Database, and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (until April 2018), and conference proceedings and previous reviews. SELECTION CRITERIA: Randomised and quasi-randomised controlled trials that assessed the effect of early planned removal of umbilical venous catheters (up to two weeks after insertion) compared to an expectant management approach or a longer fixed duration in preventing bloodstream infection and other complications in newborn infants. DATA COLLECTION AND ANALYSIS: Two review authors assessed trial eligibility independently. We planned to analyse any treatment effects in the individual trials and report the risk ratio and risk difference for dichotomous data and mean difference for continuous data, with respective 95% confidence intervals. We planned to use a fixed-effect model in meta-analyses and explore potential causes of heterogeneity in sensitivity analyses. We planned to assess the quality of evidence for the main comparison at the outcome level using "Grading of Recommendations Assessment, Development and Evaluation" (GRADE) methods. MAIN RESULTS: We did not identify any eligible randomised controlled trials. AUTHORS' CONCLUSIONS: There are no trial data to guide practice regarding early planned removal versus expectant management of PICCs in newborn infants. A simple and pragmatic randomised controlled trial is needed to resolve the uncertainty about optimal management in this common and important clinical dilemma

    An Implantable Vascularized Protein Gel Construct That Supports Human Fetal Hepatoblast Survival and Infection by Hepatitis C Virus in Mice

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    Widely accessible small animal models suitable for the study of hepatitis C virus (HCV) in vivo are lacking, primarily because rodent hepatocytes cannot be productively infected and because human hepatocytes are not easily engrafted in immunodeficient mice.We report here on a novel approach for human hepatocyte engraftment that involves subcutaneous implantation of primary human fetal hepatoblasts (HFH) within a vascularized rat collagen type I/human fibronectin (rCI/hFN) gel containing Bcl-2-transduced human umbilical vein endothelial cells (Bcl-2-HUVEC) in severe combined immunodeficient X beige (SCID/bg) mice. Maturing hepatic epithelial cells in HFH/Bcl-2-HUVEC co-implants displayed endocytotic activity at the basolateral surface, canalicular microvilli and apical tight junctions between adjacent cells assessed by transmission electron microscopy. Some primary HFH, but not Huh-7.5 hepatoma cells, appeared to differentiate towards a cholangiocyte lineage within the gels, based on histological appearance and cytokeratin 7 (CK7) mRNA and protein expression. Levels of human albumin and hepatic nuclear factor 4alpha (HNF4alpha) mRNA expression in gel implants and plasma human albumin levels in mice engrafted with HFH and Bcl-2-HUVEC were somewhat enhanced by including murine liver-like basement membrane (mLBM) components and/or hepatocyte growth factor (HGF)-HUVEC within the gel matrix. Following ex vivo viral adsorption, both HFH/Bcl-2-HUVEC and Huh-7.5/Bcl-2-HUVEC co-implants sustained HCV Jc1 infection for at least 2 weeks in vivo, based on qRT-PCR and immunoelectron microscopic (IEM) analyses of gel tissue.The system described here thus provides the basis for a simple and robust small animal model of HFH engraftment that is applicable to the study of HCV infections in vivo

    Post-intervention Status in Patients With Refractory Myasthenia Gravis Treated With Eculizumab During REGAIN and Its Open-Label Extension

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    OBJECTIVE: To evaluate whether eculizumab helps patients with anti-acetylcholine receptor-positive (AChR+) refractory generalized myasthenia gravis (gMG) achieve the Myasthenia Gravis Foundation of America (MGFA) post-intervention status of minimal manifestations (MM), we assessed patients' status throughout REGAIN (Safety and Efficacy of Eculizumab in AChR+ Refractory Generalized Myasthenia Gravis) and its open-label extension. METHODS: Patients who completed the REGAIN randomized controlled trial and continued into the open-label extension were included in this tertiary endpoint analysis. Patients were assessed for the MGFA post-intervention status of improved, unchanged, worse, MM, and pharmacologic remission at defined time points during REGAIN and through week 130 of the open-label study. RESULTS: A total of 117 patients completed REGAIN and continued into the open-label study (eculizumab/eculizumab: 56; placebo/eculizumab: 61). At week 26 of REGAIN, more eculizumab-treated patients than placebo-treated patients achieved a status of improved (60.7% vs 41.7%) or MM (25.0% vs 13.3%; common OR: 2.3; 95% CI: 1.1-4.5). After 130 weeks of eculizumab treatment, 88.0% of patients achieved improved status and 57.3% of patients achieved MM status. The safety profile of eculizumab was consistent with its known profile and no new safety signals were detected. CONCLUSION: Eculizumab led to rapid and sustained achievement of MM in patients with AChR+ refractory gMG. These findings support the use of eculizumab in this previously difficult-to-treat patient population. CLINICALTRIALSGOV IDENTIFIER: REGAIN, NCT01997229; REGAIN open-label extension, NCT02301624. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that, after 26 weeks of eculizumab treatment, 25.0% of adults with AChR+ refractory gMG achieved MM, compared with 13.3% who received placebo

    Minimal Symptom Expression' in Patients With Acetylcholine Receptor Antibody-Positive Refractory Generalized Myasthenia Gravis Treated With Eculizumab

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    The efficacy and tolerability of eculizumab were assessed in REGAIN, a 26-week, phase 3, randomized, double-blind, placebo-controlled study in anti-acetylcholine receptor antibody-positive (AChR+) refractory generalized myasthenia gravis (gMG), and its open-label extension
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