479 research outputs found

    Blue and white light electroluminescence in a multilayer OLED using a new aluminium complex

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    Synthesis, structure, optical absorption, emission and electroluminescence properties of a new blue emitting Al complex, namely, bis-(2-amino-8-hydroxyquinolinato), acetylacetonato Al(III) are reported. Multilayer OLED using the Al complex showed blue emission at 465 nm, maximum brightness of ~ 425 cd/m2 and maximum current efficiency of 0.16 cd/A. Another multilayer OLED using the Al complex doped with phosphorescent Ir complex showed 'white' light emission, CIE coordinate (0.41, 0.35), maximum brightness of ~ 970 cd/m2 and maximum current efficiency of 0.53 cd/A

    Central serous chorioretinopathy: Recent findings and new physiopathology hypothesis.

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    Central serous chorioretinopathy (CSCR) is a major cause of vision threat among middle-aged male individuals. Multimodal imaging led to the description of a wide range of CSCR manifestations, and highlighted the contribution of the choroid and pigment epithelium in CSCR pathogenesis. However, the exact molecular mechanisms of CSCR have remained uncertain. The aim of this review is to recapitulate the clinical understanding of CSCR, with an emphasis on the most recent findings on epidemiology, risk factors, clinical and imaging diagnosis, and treatments options. It also gives an overview of the novel mineralocorticoid pathway hypothesis, from animal data to clinical evidences of the biological efficacy of oral mineralocorticoid antagonists in acute and chronic CSCR patients. In rodents, activation of the mineralocorticoid pathway in ocular cells either by intravitreous injection of its specific ligand, aldosterone, or by over-expression of the receptor specifically in the vascular endothelium, induced ocular phenotypes carrying many features of acute CSCR. Molecular mechanisms include expression of the calcium-dependent potassium channel (KCa2.3) in the endothelium of choroidal vessels, inducing subsequent vasodilation. Inappropriate or over-activation of the mineralocorticoid receptor in ocular cells and other tissues (such as brain, vessels) could link CSCR with the known co-morbidities observed in CSCR patients, including hypertension, coronary disease and psychological stress

    The endothelial mineralocorticoid receptor regulates vasoconstrictor tone and blood pressure

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    Pathophysiological aldosterone (aldo)/mineralocorticoid receptor (MR) signaling has significant effects on the cardiovascular system, resulting in hypertension and cardiovascular remodeling; however, the specific contribution of the vascular MR to blood pressure regulation remains to be established. To address this question, we generated a mouse model with conditional overexpression of the MR in endothelial cells (MR-EC). In basal conditions, MR-EC mice developed moderate hypertension that could be reversed by canrenoate, a pharmacological MR antagonist. MR-EC mice presented increased contractile response of resistance arteries to vasoconstrictors (phenylephrine, thromboxane A(2) analog, angiotensin II, and endothelin 1) in the absence of vascular morphological alterations. The acute blood pressure response to angiotensin II or endothelin 1 infusion was increased in MR-EC mice compared with that in littermate controls. These observations demonstrate that enhanced MR activation in the endothelium generates an increase in blood pressure, independent of stimulation of renal tubular Na(+) transport by aldo/MR or direct activation of smooth muscle MR and establish one mechanism by which endothelial MR activation per se may contribute to impaired vascular reactivity

    Commercially available probiotic enhanced growth, digestion and immune response of Rohu (Labeo rohita) reared in earthen pond

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    The use of Probiotics in aquaculture got an importance in the previous years. Hence, present study was carried out to evaluate the effects of the commercially available dietary probiotic (a consortium of Bacillus subtilis and Saccharomyces cerevisiae) on the growth, proximate body composition, digestive enzymes, hematological parameters and immune response of rohu (Labeo rohita) in a polyculture system. Fingerlings with average body weight and length of 11.00 ± 2.34 g and 9.50 ± 5.50 cm, respectively, were stocked in 6 earthen ponds, at the rate of 200 fingerlings/pond making a total of 1200 fingerlings. The experiment was extended for 3 months in two groups i.e. probiotics treated and control groups. After three months feeding trial glucose, aspartate aminotransferase (AST), moisture content, ash contents and feed conversion rate (FCR) were significantly decreased in the probiotics supplemented group. At the same time point, Hb, MCH, HCT, total protein, plasma protein, lipid contents, final body mass and final body weight, percent weight gain, cellulase activity, protease activity and amylase activity and white blood corpuscles were significantly increased in the probiotics supplemented group. In conclusion, the use of probiotic enhanced growth, digestive enzyme activities and immune response of L. rohita in a polyculture system

    SPIRONOLACTONE FOR NONRESOLVING CENTRAL SEROUS CHORIORETINOPATHY: A RANDOMIZED CONTROLLED CROSSOVER STUDY.

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    PURPOSE: To evaluate the effect of spironolactone, a mineralocorticoid receptor antagonist, for nonresolving central serous chorioretinopathy. METHODS: This is a prospective, randomized, double-blinded, placebo-controlled crossover study. Sixteen eyes of 16 patients with central serous chorioretinopathy and persistent subretinal fluid (SRF) for at least 3 months were enrolled. Patients were randomized to receive either spironolactone 50 mg or placebo once a day for 30 days, followed by a washout period of 1 week and then crossed over to either placebo or spironolactone for another 30 days. The primary outcome measure was the changes from baseline in SRF thickness at the apex of the serous retinal detachment. Secondary outcomes included subfoveal choroidal thickness and the ETDRS best-corrected visual acuity. RESULTS: The mean duration of central serous chorioretinopathy before enrollment in study eyes was 10 ± 16.9 months. Crossover data analysis showed a statistically significant reduction in SRF in spironolactone treated eyes as compared with the same eyes under placebo (P = 0.04). Secondary analysis on the first period (Day 0-Day 30) showed a significant reduction in subfoveal choroidal thickness in treated eyes as compared with placebo (P = 0.02). No significant changes were observed in the best-corrected visual acuity. There were no complications related to treatment observed. CONCLUSION: In eyes with persistent SRF due to central serous chorioretinopathy, spironolactone significantly reduced both the SRF and the subfoveal choroidal thickness as compared with placebo

    Structure and Specificity of a Permissive Bacterial C-prenyltransferase

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    This study highlights the biochemical and structural characterization of the L-tryptophan C6 C-prenyltransferase (C-PT) PriB from Streptomyces sp. RM-5-8. PriB was found to be uniquely permissive to a diverse array of prenyl donors and acceptors including daptomycin. Two additional PTs also produced novel prenylated daptomycins with improved antibacterial activities over the parent drug

    Structure and Specificity of a Permissive Bacterial C-Prenyltransferase

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    This study highlights the biochemical and structural characterization of the L-tryptophan C6 C-prenyltransferase (C-PT) PriB from Streptomyces sp. RM-5-8. PriB was found to be uniquely permissive to a diverse array of prenyl donors and acceptors including daptomycin. Two additional PTs also produced novel prenylated daptomycins with improved antibacterial activities over the parent drug

    Lack of Renal 11 Beta-Hydroxysteroid Dehydrogenase Type 2 at Birth, a Targeted Temporal Window for Neonatal Glucocorticoid Action in Human and Mice

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    International audienceBackground Glucocorticoid hormones play a major role in fetal organ maturation. Yet, excessive glucocorticoid exposure in utero can result in a variety of detrimental effects, such as growth retardation and increased susceptibility to the development of hypertension. To protect the fetus, maternal glucocorticoids are metabolized into inactive compounds by placental 11beta-hydroxysteroid dehydrogenase type2 (11ÎČHSD2). This enzyme is also expressed in the kidney, where it prevents illicit occupation of the mineralocorticoid receptor by glucocorticoids. We investigated the role of renal 11ÎČHSD2 in the control of neonatal glucocorticoid metabolism in the human and mouse. Methods Cortisol (F) and cortisone (E) concentrations were measured in maternal plasma, umbilical cord blood and human newborn urine using HPLC. 11ÎČHSD2 activity was indirectly assessed by comparing the F/E ratio between maternal and neonatal plasma (placental activity) and between plasma and urine in newborns (renal activity). Direct measurement of renal 11ÎČHSD2 activity was subsequently evaluated in mice at various developmental stages. Renal 11ÎČHSD2 mRNA and protein expression were analyzed by quantitative RT-PCR and immunohistochemistry during the perinatal period in both species. Results We demonstrate that, at variance with placental 11ÎČHSD2 activity, renal 11ÎČHSD2 activity is weak in newborn human and mouse and correlates with low renal mRNA levels and absence of detectable 11ÎČHSD2 protein. Conclusions We provide evidence for a weak or absent expression of neonatal renal 11ÎČHSD2 that is conserved among species. This temporal and tissue-specific 11ÎČHSD2 expression could represent a physiological window for glucocorticoid action yet may constitute an important predictive factor for adverse outcomes of glucocorticoid excess through fetal programming

    Multiple Translocation of the AVR-Pita Effector Gene among Chromosomes of the Rice Blast Fungus Magnaporthe oryzae and Related Species

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    Magnaporthe oryzae is the causal agent of rice blast disease, a devastating problem worldwide. This fungus has caused breakdown of resistance conferred by newly developed commercial cultivars. To address how the rice blast fungus adapts itself to new resistance genes so quickly, we examined chromosomal locations of AVR-Pita, a subtelomeric gene family corresponding to the Pita resistance gene, in various isolates of M. oryzae (including wheat and millet pathogens) and its related species. We found that AVR-Pita (AVR-Pita1 and AVR-Pita2) is highly variable in its genome location, occurring in chromosomes 1, 3, 4, 5, 6, 7, and supernumerary chromosomes, particularly in rice-infecting isolates. When expressed in M. oryzae, most of the AVR-Pita homologs could elicit Pita-mediated resistance, even those from non-rice isolates. AVR-Pita was flanked by a retrotransposon, which presumably contributed to its multiple translocation across the genome. On the other hand, family member AVR-Pita3, which lacks avirulence activity, was stably located on chromosome 7 in a vast majority of isolates. These results suggest that the diversification in genome location of AVR-Pita in the rice isolates is a consequence of recognition by Pita in rice. We propose a model that the multiple translocation of AVR-Pita may be associated with its frequent loss and recovery mediated by its transfer among individuals in asexual populations. This model implies that the high mobility of AVR-Pita is a key mechanism accounting for the rapid adaptation toward Pita. Dynamic adaptation of some fungal plant pathogens may be achieved by deletion and recovery of avirulence genes using a population as a unit of adaptation

    Lit up and left dark: Failures of imagination in urban broadband networks

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    The design and deployment of urban broadband infrastructures inscribe particular imaginations of Internet access onto city streets. The different manifestations and locations of these networks, their uses, and access points often expose material excesses of urban broadband networks, as well as failures of Internet service providers, urban planners, and public officials to imagine the diverse ways that people incorporate Internet connection into their everyday lives. We approach the study of urban broadband networks through the juxtaposition of invisible networks that are buried under the streets and have always been “turned off” (dark fiber) versus hypervisible that are “turned on” and prominently displayed on city streets (LinkNYC). In our analysis of these two case studies, we critique themes of visibility and invisibility as indexes of power and access. Our findings are meant to provide a critical analysis of urban technology policy as well as theories of infrastructure, visibility, and access
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