794 research outputs found

    Photoredox catalysis under shear using thin film vortex microfluidics

    Get PDF
    Open Access Article. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.A microfluidic vortex fluidic device (VFD) operating in either confined or continuous mode is effective in high yielding photoredox reactions involving Rose Bengal, with short reaction times. This processing can be translated to multi-components reactions, also with significantly reduced processing times relative to batch processing and channel microfluidic processing, with comparable or improved yields

    Retour sur la fondation de l’Abbaye du Mont-Saint-Michel et le rîle du duc Richard Ier de Normandie

    Get PDF
    Le point de vue traditionnellement admis selon lequel l’abbaye du Mont Saint-Michel fut fondĂ©e vers 965 par le duc normand Richard I a Ă©tĂ© largement remis en question au cours des derniĂšres dĂ©cennies car il constitue une narration normande, Ă©crite a posteriori dans un but apologĂ©tique. Que Richard ait contrĂŽlĂ© la partie Ouest de son duchĂ© Ă  une date si prĂ©coce, si toutefois il l’a contrĂŽlĂ©e un jour, condamne cette interprĂ©tation. D’autres hypothĂšses ont Ă©tĂ© avancĂ©es, par exemple que des bĂ©nĂ©dictins bretons aient prĂ©cĂ©dĂ© l’arrivĂ©e des Normands et que ceux-ci, de toute façon, ne se seraient pas beaucoup intĂ©ressĂ©s Ă  l’ülot avant le dĂ©but du xie siĂšcle. Cet article examine ces nouvelles thĂ©ories et montre qu’elles sont peu convaincantes. L’auteur soutient que la communautĂ© de clercs installĂ©e par l’évĂȘque Aubert d’Avranches vers 709 Ă©tait toujours responsable de ce lieu de pĂšlerinage au milieu du xe siĂšcle ; que Richard Ier les a remplacĂ© par des bĂ©nĂ©dictins en 965 faisant ainsi un geste politique afin d’obtenir une paix avec l’empereur Otton Ier, le roi franc Lothair et le comte de Blois, Thibaud ; qu’au mĂȘme moment il a expulsĂ© les clercs ; et que, par la suite, il a ignorĂ© sa nouvelle abbaye qui, par consĂ©quent, a dĂ» lutter pendant une gĂ©nĂ©ration avant d’ĂȘtre bien Ă©tablie.The traditional belief that the abbey of Mont Saint-Michel was founded in c.965 by the Norman duke Richard I has been widely questioned in recent decades. It has been represented as essentially an ex post facto and self-serving Norman narrative, the veracity of which is put in doubt by the improbability (it is said) that Richard exercised any control over the west of his duchy at such an early date, if he ever did. Alternative possibilities have been promoted, such as that Breton benedictines preceded the Normans and that the latter did not even take much interest in the island until early in the 11th century. This article re-examines the new orthodoxies and finds them unpersuasive. It argues that the community of clerks installed in c.709 by Bishop Aubert of Avranches was still in charge of the pilgrimage shrine in the mid-10th century; that Richard I replaced them with benedictines in 965 as a political gesture, to help secure a peace with the Emperor Otto the Great, the Frankish king Lothar and Count Thibaud of Blois; that he simultaneously expelled the clerks and thereafter ignored his new abbey, which consequently struggled for a generation to become established

    Proglacial Lakes Control Glacier Geometry and Behavior During Recession

    Get PDF
    Ice‐contact proglacial lakes are generally absent from numerical model simulations of glacier evolution, and their effects on ice dynamics and on rates of deglaciation remain poorly quantified. Using the BISICLES ice flow model, we analyzed the effects of an ice‐contact lake on the Pukaki Glacier, New Zealand, during recession from the Last Glacial Maximum. The ice‐contact lake produced a maximum effect on grounding line recession >4 times further and on ice velocities up to 8 times faster, compared to simulations of a land‐terminating glacier forced by the same climate. The lake contributed up to 82% of cumulative grounding line recession and 87% of ice velocity during the first 300 years of the simulations, but those values decreased to just 6% and 37%, respectively, after 5,000 years. Numerical models that ignore lake interactions will, therefore, misrepresent the rate of recession especially during the transition of a land‐terminating to a lake‐terminating environment

    Including Aortic Valve Morphology in Computational Fluid Dynamics Simulations: Initial Findings and Application to Aortic Coarctation

    Get PDF
    Computational fluid dynamics (CFD) simulations quantifying thoracic aortic flow patterns have not included disturbances from the aortic valve (AoV). 80% of patients with aortic coarctation (CoA) have a bicuspid aortic valve (BAV) which may cause adverse flow patterns contributing to morbidity. Our objectives were to develop a method to account for the AoV in CFD simulations, and quantify its impact on local hemodynamics. The method developed facilitates segmentation of the AoV, spatiotemporal interpolation of segments, and anatomic positioning of segments at the CFD model inlet. The AoV was included in CFD model examples of a normal (tricuspid AoV) and a post-surgical CoA patient (BAV). Velocity, turbulent kinetic energy (TKE), time-averaged wall shear stress (TAWSS), and oscillatory shear index (OSI) results were compared to equivalent simulations using a plug inlet profile. The plug inlet greatly underestimated TKE for both examples. TAWSS differences extended throughout the thoracic aorta for the CoA BAV, but were limited to the arch for the normal example. OSI differences existed mainly in the ascending aorta for both cases. The impact of AoV can now be included with CFD simulations to identify regions of deleterious hemodynamics thereby advancing simulations of the thoracic aorta one step closer to reality

    The precautions of clinical waste: disposable medical sharps in the United Kingdom

    Get PDF
    This article deals with recent changes in UK guidance on clinical waste, in particular a shift to disposable, single-use instruments and sharps. I use interviews conducted with nurses from a GP practice and two clinical waste managers at alternative treatment and incineration sites as a springboard for reflection on the relationship between the legislation on clinical waste management and its implementation. Scrutinizing the UK guidance, European legislation and World Health Organization principles, I draw out interviewees’ concerns that the changed practices lead to an expansion of the hazardous waste category, with an increased volume going to incineration. This raises questions regarding the regulations’ environmental and health effects, and regarding the precautionary approach embedded in the regulations. Tracing the diverse reverberations of the term ‘waste’ in different points along the journeys made by sharps in particular, and locating these questions in relation to existing literature on waste, I emphasize that public health rationales for the new practices are not made clear in the guidance. I suggest that this relative silence on the subject conceals both the uncertainties regarding the necessity for these means of managing the risks of infectious waste, and the tensions between policies of precautionary public health and environmental sustainability

    Treating anxiety and depression in older adults: Randomised controlled trial comparing guided V. Self-guided internet-delivered cognitive-behavioural therapy

    Full text link
    © 2016 The Royal College of Psychiatrists. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) licence. Background Symptoms of anxiety and depression are prevalent in older adults. Aims To compare clinician-guided and self-guided versions of a transdiagnostic internet-delivered cognitive-behavioural therapy (iCBT) intervention for adults aged 60 years and above. Method Adults (n=433) with symptoms of anxiety and depression were randomly allocated to: (1) clinician-guided treatment (n=153); (2) initial clinician interview followed by self-guided treatment (n=140); or (3) self-guided treatment without interview (n=140). Results Large reductions (d ≄1.00) in symptoms of depression and anxiety were observed across groups, and sustained at follow-up. No differences were observed in clinical outcomes or satisfaction ratings. Age did not affect outcomes. Conclusions Carefully developed iCBT interventions may significantly reduce symptoms of anxiety and depression in older adults when delivered in either clinician-guided or self-guided formats

    Light and Electron Microscopy Study of Glycogen Synthase Kinase-3ÎČ in the Mouse Brain

    Get PDF
    Glycogen synthase kinase-3ÎČ (GSK3ÎČ) is highly abundant in the brain. Various biochemical analyses have indicated that GSK3ÎČ is localized to different intracellular compartments within brain cells. However, ultrastructural visualization of this kinase in various brain regions and in different brain cell types has not been reported. The goal of the present study was to examine GSK3ÎČ distribution and subcellular localization in the brain using immunohistochemistry combined with light and electron microscopy. Initial examination by light microscopy revealed that GSK3ÎČ is expressed in brain neurons and their dendrites throughout all the rostrocaudal extent of the adult mouse brain, and abundant GSK3ÎČ staining was found in the cortex, hippocampus, basal ganglia, the cerebellum, and some brainstem nuclei. Examination by transmission electron microscopy revealed highly specific subcellular localization of GSK3ÎČ in neurons and astrocytes. At the subcellular level, GSK3ÎČ was present in the rough endoplasmic reticulum, free ribosomes, and mitochondria of neurons and astrocytes. In addition GSK3ÎČ was also present in dendrites and dendritic spines, with some postsynaptic densities clearly labeled for GSK3ÎČ. Phosphorylation at serine-9 of GSK3ÎČ (pSer9GSK3ÎČ) reduces kinase activity. pSer9GSK3ÎČ labeling was present in all brain regions, but the pattern of staining was clearly different, with an abundance of labeling in microglia cells in all regions analyzed and much less neuronal staining in the subcortical regions. At the subcellular level pSer9GSK3ÎČ labeling was located in the endoplasmic reticulum, free ribosomes and in some of the nuclei. Overall, in normal brains constitutively active GSK3ÎČ is predominantly present in neurons while pSer9GSK3ÎČ is more evident in resting microglia cells. This visual assessment of GSK3ÎČ localization within the subcellular structures of various brain cells may help in understanding the diverse role of GSK3ÎČ signaling in the brain

    The role of diet and lifestyle in women with breast cancer: An update review of related research in the Middle East

    Get PDF
    © Zainab Taha and Sakina E. Eltom 2018. Breast cancer is the most common malignancy among Arab women in Eastern Mediterranean Region (EMR). The incidence of breast cancer has substantially increased in recent years among this women population, especially those younger than 50, and the incidence is expected to double by 2030. Considerable experimental evidence supports the potential role of dietary habits and lifestyle in cancer etiology and cancer prevention. In this review we examined the literature for evidence to link dietary choices and the rise in incidence and mortality of breast cancer among women in EMR. A literature search was conducted in PubMed and Ovid MEDLINE databases up to December 2017. The search terms used are breast cancer prevalence, breast cancer incidence worldwide, breast cancer and: nutrition, protein intake, Vitamin D intake, fat intake, phytoestrogens, EMR, Arab, Middle East, Gulf countries, the UAE Arab women, breast cancer risk, diet, and chemoprevention. We found evidence to suggest that there is an alarming epidemic of obesity among women in most of the EMR countries, especially Gulf Cooperation Council (GCC) countries. The rise in the new breast cancer cases among women could be attributed to excess body weight. Their dietary pattern, which correlates with obesity, can be an important factor in the etiology of cancer. Although very few studies were found to support a direct causal relationship between obesity and breast cancer in the EMR, circumstantial evidence clearly points to the possible role of the epidemic, obesity, in this population and the startling rise in cases of breast cancer. Well-designed and systematic studies are urgently needed to confirm these associations and to elucidate potential mechanisms. More urgently, calls to action are needed in many sectors and at all levels of society, to establish intensive strategies for reducing obesity and promoting an overall healthy diet. Continued and expanded research on diet, lifestyle, and breast cancer risk is urgently needed to build the foundation for future progress in evidence-based public health efforts

    Enzymatic Metabolism of Ergosterol by Cytochrome P450scc to Biologically Active 17α,24-Dihydroxyergosterol

    Get PDF
    SummaryWe demonstrate the metabolism of ergosterol by cytochrome P450scc in either a reconstituted system or isolated adrenal mitochondria. The major reaction product was identified as 17α,24-dihydroxyergosterol. Purified P450scc also generated hydroxyergosterol as a minor product, which is probably an intermediate in the synthesis of 17α,24-dihydroxyergosterol. In contrast to cholesterol and 7-dehydrocholesterol, cleavage of the ergosterol side chain was not observed. NMR analysis clearly located one hydroxyl group to C24, with evidence that the second hydroxyl group is at C17. 17α,24-Dihydroxyergosterol inhibited cell proliferation of HaCaT keratinocytes and melanoma cells. Thus, in comparison with cholesterol and 7-dehydrocholesterol, the 24-methyl group and the C22-C23 double bond of ergosterol prevent side chain cleavage by P450scc and change the enzyme’s hydroxylase activity from C22 and C20, to C24 and C17, generating bioactive product
    • 

    corecore