76 research outputs found

    Acetylene-linked conjugated polymers for sacrificial photocatalytic hydrogen evolution from water

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    Conjugated organic polymers have shown potential as photocatalysts for hydrogen production by water splitting. Taking advantage of a high throughput screening workflow, two series of acetylene-linked co-polymers were prepared and studied for their potential as photocatalysts for sacrificial hydrogen production from water. It was found that a triethynylbenzene-based polymer with a dibenzo[b,d]thiophene sulfone linker (TE11) had the highest performance in terms of hydrogen evolution rate under visible illumination in the presence of a sacrificial hole-scavenger. Synthetically elaborating the triethynylbenzene linker in TE11 by changing the core and by introducing nitrogen, the resulting hydrogen evolution rate was further increased by a factor of nearly two

    Cannabinoid receptor CB1 mediates baseline and activity-induced survival of new neurons in adult hippocampal neurogenesis

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    <p>Abstract</p> <p>Background</p> <p>Adult neurogenesis is a particular example of brain plasticity that is partially modulated by the endocannabinoid system. Whereas the impact of synthetic cannabinoids on the neuronal progenitor cells has been described, there has been lack of information about the action of plant-derived extracts on neurogenesis. Therefore we here focused on the effects of Δ9-tetrahydrocannabinol (THC) and Cannabidiol (CBD) fed to female C57Bl/6 and Nestin-GFP-reporter mice on proliferation and maturation of neuronal progenitor cells and spatial learning performance. In addition we used cannabinoid receptor 1 (CB1) deficient mice and treatment with CB1 antagonist AM251 in Nestin-GFP-reporter mice to investigate the role of the CB1 receptor in adult neurogenesis in detail.</p> <p>Results</p> <p>THC and CBD differed in their effects on spatial learning and adult neurogenesis. CBD did not impair learning but increased adult neurogenesis, whereas THC reduced learning without affecting adult neurogenesis. We found the neurogenic effect of CBD to be dependent on the CB1 receptor, which is expressed over the whole dentate gyrus. Similarly, the neurogenic effect of environmental enrichment and voluntary wheel running depends on the presence of the CB1 receptor. We found that in the absence of CB1 receptors, cell proliferation was increased and neuronal differentiation reduced, which could be related to CB1 receptor mediated signaling in Doublecortin (DCX)-expressing intermediate progenitor cells.</p> <p>Conclusion</p> <p>CB1 affected the stages of adult neurogenesis that involve intermediate highly proliferative progenitor cells and the survival and maturation of new neurons. The pro-neurogenic effects of CBD might explain some of the positive therapeutic features of CBD-based compounds.</p

    The emerging modern face of mood disorders: a didactic editorial with a detailed presentation of data and definitions

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    The present work represents a detailed description of our current understanding and knowledge of the epidemiology, etiopathogenesis and clinical manifestations of mood disorders, their comorbidity and overlap, and the effect of variables such as gender and age. This review article is largely based on the 'Mood disorders' chapter of the Wikibooks Textbook of Psychiatry http://en.wikibooks.org/wiki/Textbook_of_Psychiatry/Mood_Disorders

    Fungal G-protein-coupled receptors::mediators of pathogenesis and targets for disease control

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    G-protein signalling pathways are involved in sensing the environment, enabling fungi to coordinate cell function, metabolism and development with their surroundings, thereby promoting their survival, propagation and virulence. G-protein-coupled receptors (GPCRs) are the largest class of cell surface receptors in fungi. Despite the apparent importance of GPCR signalling to fungal biology and virulence, relatively few GPCR–G-protein interactions, and even fewer receptor-binding ligands, have been identified. Approximately 40% of current pharmaceuticals target human GPCRs, due to their cell surface location and central role in cell signalling. Fungal GPCRs do not belong to any of the mammalian receptor classes, making them druggable targets for antifungal development. This Review Article evaluates developments in our understanding of fungal GPCR-mediated signalling, while substantiating the rationale for considering these receptors as potential antifungal targets. The need for insights into the structure–function relationship of receptor–ligand interactions is highlighted, which could facilitate the development of receptor-interfering compounds that could be used in disease control

    Comparing American Gastroenterological Association Pancreatic Cyst Management Guidelines with Fukuoka Consensus Guidelines as Predictors of Advanced Neoplasia in Patients with Suspected Pancreatic Cystic Neoplasms

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    In 2015, the American Gastroenterological Association (AGA) published guidelines to provide recommendations for management of suspected pancreatic cystic neoplasms (PCNs). The aim of this study was to compare efficacy of these with the Fukuoka consensus guidelines in predicting advanced neoplasia (AN) in patients with suspected PCNs. We performed a retrospective study of 239 patients who underwent surgical resection for suspected mucinous PCN at a tertiary care center from 2000 to 2014. Surgical pathology was the gold standard. The AGA and Fukuoka criteria were applied, and their performance in predicting AN, defined as invasive cancer or high-grade dysplasia (HGD), was assessed. Advanced neoplasia was found in 71 of 239 (29.7%) patients (28 invasive cancer, 43 HGD). The Fukuoka "high-risk" (FG-HR) and AGA "high-risk" (AGA-HR) criteria identified patients with AN with sensitivities of 28.2% and 35.2%, specificities of 95.8% and 94.0%, positive predictive values of 74.1% and 71.4%, and negative predictive values of 75.9% and 77.5%, respectively. Overall, there was no significant difference between the guidelines for prediction of AN. There were 7 and 6 cases with invasive cancer, and 23 and 24 cases with HGD missed by the FG-HR and AGA-HR guidelines, respectively. In a retrospective analysis, the AGA guidelines are not superior to the Fukuoka guidelines in identifying AN in suspected PCNs. Both sets of guidelines have fair PPV for detection of AN, which would lead to avoidable resections in patients without AN. Additionally, the high-risk features of both guidelines do not accurately identify all patients with AN
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