Local Characterization of Field Emission Properties of Graphene Flowers

An experimental study about field emission properties of commercially available graphene flowers cloth is reported. Material characterization by means of x-ray diffraction, Raman spectroscopy, and x-ray photoemission spectroscopy confirms the formation of high quality vertical few-layers graphene nanosheets. A tip-anode setup is exploited in which nanomanipulated tungsten tip is used as the anode at controlled distance from the emitter in order to reduce the effective emitting area below 1 μm2, giving access to local characterization. A turn-on field as low as 0.07 V nm−1 and field enhancement factor up to 32 for very small cathode–anode separation distances is demonstrated, in the range 400–700 nm. It is also shown that the turn-on field increases for increasing distances, while the field enhancement factor decreases. Finally, time stability of the field emission current is reported, evidencing a reduction of the fluctuations for lower current levels

THIOSUGARS AS VECTORS FOR G-QUADRUPLEX LIGANDS: ANTICANCER AND ANTIPARASITIC DRUGS.

Congresos y Conferencias: Comunicación de Congreso - Conferencia invitada

Thiosugar naphthalene diimide conjugates: G-quadruplex ligands with antiparasitic and anticancer activity.

Glycosyl conjugation to drugs is a strategy being used to take advantage of glucose transporters (GLUT) overexpression in cancer cells in comparison with non-cancerous cells. Its extension to the conjugation of drugs to thiosugars tries to exploit their higher biostability when compared to O-glycosides. Here, we have synthesized a series of thiosugar naphthalene diimide conjugates as G-quadruplex ligands and have explored modifications of the amino sidechain comparing dimethyl amino and morpholino groups. Then, we studied their antiproliferative activity in colon cancer cells, and their antiparasitic activity in T. brucei and L. major parasites, together with their ability to bind quadruplexes and their cellular uptake and location. We observed higher toxicity for the sugar-NDI-NMe2 derivatives than for the sugar-NDI-morph compounds, both in mammalian cells and in parasites. Our experiments indicate that a less efficient binding to quadruplexes and a worse cellular uptake of the carb-NDI-morph derivatives could be the reasons for these differences. We found small variations in cytotoxicity between O-carb-NDIs and S-carb-NDIs, except against non-cancerous human fibroblasts MRC-5, where thiosugar-NDIs tend to be less toxic. This leads to a notable selectivity for β-thiomaltosyl-NDI-NMe2 12 (9.8 fold), with an IC50 of 0.3 μM against HT-29 cells. Finally, the antiparasitic activity observed for the carb-NDI-NMe2 derivatives against T. brucei was in the nanomolar range with a good selectivity index in the range of 30- to 69- fold.This work was funded by the Spanish Ministerio de Economía y Competitividad (RTI2018-099036-B-I00; EUIN2017-88791), Agence Nationale de la Recherche (ANR-20-CE12-0023, ANR-18-CE29-0013-POLYnESI) and INCa grants G4Access and A.B. was supported by an AIRC fellowship

Groundbreaking Anticancer Activity of Highly Diversified Oxadiazole Scaffolds

Nowadays, an increasing number of heterocyclic-based drugs found application in medicinal chemistry and, in particular, as anticancer agents. In this context, oxadiazoles-five-membered aromatic rings-emerged for their interesting biological properties. Modification of oxadiazole scaffolds represents a valid strategy to increase their anticancer activity, especially on 1,2,4 and 1,3,4 regioisomers. In the last years, an increasing number of oxadiazole derivatives, with remarkable cytotoxicity for several tumor lines, were identified. Structural modifications, that ensure higher cytotoxicity towards malignant cells, represent a solid starting point in the development of novel oxadiazole-based drugs. To increase the specificity of this strategy, outstanding oxadiazole scaffolds have been designed to selectively interact with biological targets, including enzymes, globular proteins, and nucleic acids, showing more promising antitumor effects. In the present work, we aim to provide a comprehensive overview of the anticancer activity of these heterocycles, describing their effect on different targets and highlighting how their structural versatility has been exploited to modulate their biological properties

Cardiac surgery in patients with acute intermittent porphyria

Acute intermittent porphyria (AIP) is a disorder of the heme biosynthesis pathway of a specific inherited enzymatic defect. Many different environmental factors such as drugs, calorie restriction, infection etc., often play a key role in triggering a porphiric acute attack. We describe a 50-year-old woman with AIP who underwent aortic valve replacement due to acute infective endocarditis and review the perioperative management of these patients. \ua9 2011 Wiley Periodicals, Inc

CABG Versus PCI in the Treatment of Diabetic Patients Affected by Coronary Artery Disease

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CABG Versus PCI in the Treatment of Diabetic Patients Affected by Coronary Artery Disease. Which is the Best Option?

Surgical coronary revascularization and percutaneous coronary intervention were demonstrated to be effective treatments for coronary artery disease. However, the optimal revascularization strategy remains unclear in certain patient subsets. The recently published Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multivessel Disease (FREEDOM) trial is a randomized study evaluating the use of CABG versus PCI in diabetic patients with multivessel coronary disease. The purpose of this study was to review the available literature based on randomized trials and observational studies in order to allow clinicians to make evidence-based decisions when treating diabetic patients with multivessel coronary disease. The current evidence suggests that CABG should remain the standard of care for this patient population

Developmental dyslexia in a regular orthography. Can the reading profile be reduced to strategic control?

In languages with regular orthographies, the identification of different forms of reading impairment (such as surface or phonological dyslexia) has proved elusive. Alternatively, it has been proposed that different patterns of errors depend upon strategic choices on the part of the reader. The present study aimed to test this strategic interpretation by evaluating the effectiveness of instructions to read quickly (or accurately) in modifying the reading rate and types of errors of dyslexic children. Further, drawing on an error classification based on the contrast between sounding-out behaviour and word substitution, we examined the types of reading error that best characterize the deficit in a language with regular orthography (Italian). Thirty children with dyslexia and 30 chronologically age-matched controls read aloud passages and word lists with instructions to emphasize either rate or accuracy. When asked to read quickly, children with dyslexia increased their reading rate (although less than skilled children). However, the type of instructions had little influence on reading errors. Therefore, the results did not support the view that strategic control has an important role in modulating the types of reading errors made by children with dyslexia. For word lists, sounding-out behaviour, errors in stress assignment, and form-related nonwords were useful to correctly identifying children with dyslexia. For text passages, sounding-out behaviour and form-related errors were the best predictors of group membership. Thus, specific types of errors are a fundamental component of the reading deficit in children who speak a language with regular orthography over and above their reading slowness

Developmental dyslexia in a regular orthography: can the reading profile be reduced to strategic control?

In languages with regular orthographies, the identification of different forms of reading impairment (such as surface or phonological dyslexia) has proved elusive. Alternatively, it has been proposed that different patterns of errors depend upon strategic choices on the part of the reader. The present study aimed to test this strategic interpretation by evaluating the effectiveness of instructions to read quickly (or accurately) in modifying the reading rate and types of errors of dyslexic children. Further, drawing on an error classification based on the contrast between sounding-out behaviour and word substitution, we examined the types of reading error that best characterize the deficit in a language with regular orthography (Italian). Thirty children with dyslexia and 30 chronologically age-matched controls read aloud passages and word lists with instructions to emphasize either rate or accuracy. When asked to read quickly, children with dyslexia increased their reading rate (although less than skilled children). However, the type of instructions had little influence on reading errors. Therefore, the results did not support the view that strategic control has an important role in modulating the types of reading errors made by children with dyslexia. For word lists, sounding-out behaviour, errors in stress assignment, and form-related nonwords were useful to correctly identifying children with dyslexia. For text passages, sounding-out behaviour and form-related errors were the best predictors of group membership. Thus, specific types of errors are a fundamental component of the reading deficit in children who speak a language with regular orthography over and above their reading slowness