669 research outputs found

    Physical Study by Surface Characterizations of Sarin Sensor on the Basis of Chemically Functionalized Silicon Nanoribbon Field Effect Transistor

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    Surface characterizations of an organophosphorus (OP) gas detector based on chemically functionalized silicon nanoribbon field-effect transistor (SiNR-FET) were performed by Kelvin Probe Force Microscopy (KPFM) and ToF-SIMS, and correlated with changes in the current-voltage characteristics of the devices. KPFM measurements on FETs allow (i) to investigate the contact potential difference (CPD) distribution of the polarized device as function of the gate voltage and the exposure to OP traces and, (ii) to analyze the CPD hysteresis associated to the presence of mobile ions on the surface. The CPD measured by KPFM on the silicon nanoribbon was corrected due to side capacitance effects in order to determine the real quantitative surface potential. Comparison with macroscopic Kelvin probe (KP) experiments on larger surfaces was carried out. These two approaches were quantitatively consistent. An important increase of the CPD values (between + 399 mV and + 302 mV) was observed after the OP sensor grafting, corresponding to a decrease of the work function, and a weaker variation after exposure to OP (between - 14 mV and - 61 mV) was measured. Molecular imaging by ToF-SIMS revealed OP presence after SiNR-FET exposure. The OP molecules were essentially localized on the Si-NR confirming effectiveness and selectivity of the OP sensor. A prototype was exposed to Sarin vapors and succeeded in the detection of low vapor concentrations (40 ppm).Comment: Paper and supporting information, J. Phys. Chem. C, 201

    Transient model of a Professional Oven

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    Tackling the climate change by reducing energy consumption is among the biggest, most urgent challenges society is facing and requires a continuous efficiency improvement of thermal systems. Appropriate design strategies, developed a priori and then experimentally validated according to suitable test protocols on a prototype, are needed in order to reach potential energy saving targets. These strategies can successfully be implemented in the food service sector, where cooking appliances, in particular, present many possibilities for improving energy savings. Therefore, a valuable design methodology should take into account not only steady state operating conditions but also the transient behaviours of the device, which must be described by means of specially developed theoretical dynamic models. The operating profile of an oven, for example, consists of a sequence of unsteady phases (cavity heating-up, food introduction and extraction, switching from one cooking mode to another) interspersed with steady cooking phases. The dynamic model presented in this paper defines the energy conservation equations of a professional oven, where a high temperature thermal source positioned inside its cavity produces thermal power radiated and modulated over time, according to a suitable control strategy. In particular, when the temperature in the cooking zone of the cavity has reached a specified set point, this is thermostatically controlled in time, depending on the cooking phase. The resulting equation system is then solved by means of numerical methods. With this code, it is possible to support the design phase of both the structure and the control strategy of the oven. It permits, for example, to get a general understanding of the best possible configurations and combinations of insulation materials for the cavity walls or, with reference to the control strategy, to simulate different cooking procedures, with the aim of optimizing the operating sequence of the oven, reaching the maximum energy saving without reducing the cooking quality. The code, validated by comparison with a set of experimental data obtained with a current production model, will be applied in the design phase of a new line of high efficiency professional ovens

    Oesophageal cancer in women: tobacco, alcohol, nutritional and hormonal factors

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    We analysed 3 case–control studies from Italy and Switzerland including 114 women with squamous cell oesophageal cancer and 425 controls. The multivariate odds ratio was 4.5 for heavy smoking and 5.4 for heavy alcohol drinking. Fruit intake, vegetable intake, oral contraceptive and HRT use were inversely related to oesophageal cancer. © 2001 Cancer Research Campaign http://www.bjcancer.co

    Comparison between Two Different Two-Stage Transperineal Approaches to Treat Urethral Strictures or Bladder Neck Contracture Associated with Severe Urinary Incontinence that Occurred after Pelvic Surgery: Report of Our Experience

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    Introduction. The recurrence of urethral/bladder neck stricture after multiple endoscopic procedures is a rare complication that can follow prostatic surgery and its treatment is still controversial. Material and Methods. We retrospectively analyzed our data on 17 patients, operated between September 2001 and January 2010, who presented severe urinary incontinence and urethral/bladder neck stricture after prostatic surgery and failure of at least four conservative endoscopic treatments. Six patients underwent a transperineal urethrovesical anastomosis and 11 patients a combined transperineal suprapubical (endoscopic) urethrovesical anastomosis. After six months the patients that presented complete incontinence and no urethral stricture underwent the implantation of an artificial urethral sphincter (AUS). Results. After six months 16 patients were completely incontinent and presented a patent, stable lumen, so that they underwent an AUS implantation. With a mean followup of 50.5 months, 14 patients are perfectly continent with no postvoid residual urine. Conclusions. Two-stage procedures are safe techniques to treat these challenging cases. In our opinion, these cases could be managed with a transperineal approach in patients who present a perfect operative field; on the contrary, in more difficult cases, it would be preferable to use the other technique, with a combined transperineal suprapubical access, to perform a pull-through procedure

    Detecting neurodevelopmental trajectories in congenital heart diseases with a machine-learning approach

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    We aimed to delineate the neuropsychological and psychopathological profiles of children with congenital heart disease (CHD) and look for associations with clinical parameters. We conducted a prospective observational study in children with CHD who underwent cardiac surgery within five years of age. At least 18\ua0months after cardiac surgery, we performed an extensive neuropsychological (intelligence, language, attention, executive function, memory, social skills) and psychopathological assessment, implementing a machine-learning approach for clustering and influencing variable classification. We examined 74 children (37 with CHD and 37 age-matched controls). Group comparisons have shown differences in many domains: intelligence, language, executive skills, and memory. From CHD questionnaires, we identified two clinical subtypes of psychopathological profiles: a small subgroup with high symptoms of psychopathology and a wider subgroup of patients with ADHD-like profiles. No associations with the considered clinical parameters were found. CHD patients are prone to high interindividual variability in neuropsychological and psychological outcomes, depending on many factors that are difficult to control and study. Unfortunately, these dysfunctions are under-recognized by clinicians. Given that brain maturation continues through childhood, providing a significant window for recovery, there is a need for a lifespan approach to optimize the outcome trajectory for patients with CHD

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    The present paper features the publication of an unedited manuscript by the Soviet linguist E.D. Polivanov, submitted in November 1927 by its author not for publication but just as a contribu- tion to the discussion around the so-called Abkhaz Analytical Alphabet. is graphic system was devised by the academician Nikolay Yakovlevich Marr on the basis of the Latin alphabet for the representation of all Japhetic (Caucasian) languages. In the rst section of the introduction, the main characteristics of Marr\u2019s Analytical Alphabet are presented; the second section addresses the linguistic discussion that followed its introduction in Abkhazia as the o cial alphabet in 1926 and its replacement two years later by a Latin-based alphabet. e third section gives comment on some questions of Abkhaz phonetics and transcription; the fourth is devoted to textual and editorial is- sues. e edition of the Russian text is accompanied by an English translation, prepared by Grazia Giannetta (Macerata)

    SISTEMÁTICA Y DISTRIBUCIÓN DEL GÉNERO LUTICOLA D.G. MANN (BACILLARIOPHYTA) EN ARGENTINA

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    Los objetivos de mi tesis doctoral son evaluar la riqueza del género de diatomeas Luticola en Argentina, explorar las relaciones filogenéticas del mismo e identificar los patrones de distribución de las especies encontradas en nuestro país. Para ello mi trabajo se centra en cinco brazos principales, estos son la revisión bibliográfica, la consulta de colecciones, el análisis de muestras adquiridas a campo, los análisis moleculares a partir de cultivos unialgales y el desarrollo de mapas de distribución de las especies. Para la revisión bibliográfica analizaré los trabajos en los cuales se citen especies del género en estudio en el país. En cuanto a la consulta de colecciones, principalmente trabajaré con materiales de la Colección de la División Ficología, FCNyM, siendo de especial importancia la Colección de Diatomeas Argentinas Dr. Joaquín Frenguelli, en la cual se encuentran varios materiales tipos del género Luticola. Para la obtención de muestras se realizarán campañas de muestreo a distintas regiones del país. Se tomarán muestras cualitativas (multihábitat) de perifiton, midiendo altitud, coordenadas geográficas y parámetros físicos y químicos del agua. Las muestras colectadas serán conservadas en frío y oscuridad hasta ser llevadas al laboratorio. Parte de estas muestras serán utilizadas para realizar análisis con microscopía óptica y electrónica de barrido y otras para aislamientos y cultivos. Las muestras serán analizadas con microscopio óptico (MO) con contraste de fases e interferencia y microscopio electrónico de barrido (MEB), para esto es necesario eliminar la materia orgánica, lo cual se realizará con peróxido de hidrógeno o peróxido de hidrógeno y dicromato de potasio. El material tratado será montado en Naphrax para su observación con MO y sobre tacos de vidrio y metalizadas con oro para su estudio con MEB. Por otra parte se establecerán cultivos unialgales en medios de cultivo a temperatura y luz controladas. A partir de aquellos cultivos que prosperen se realizará la extracción del ADN y se secuenciaran distintos marcadores que se utilizarán para establecer las relaciones filogenéticas del género. Para establecer los patrones de distribución de las especies se realizará un Análisis de Parsimonia de Endemismos (PAE) basado en localidades. Los resultados de este análisis se compararán con esquemas biogeográficos establecidos a partir de otros grupos de organismos. Los datos biológicos, físicos y químicos serán reunidos en Sistema de Información Geográfica. Los mapas de distribución de las especies se realizarán usando el software QGIS

    Efficacy of fipronil/(S)-methoprene/eprinomectin/praziquantel (Broadline®) against Thelazia callipaeda in naturally infected cats

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    Background: The present clinical field trial was conducted to assess the efficacy of a broad-spectrum parasiticide spot-on formulation containing eprinomectin (Broadline®) against Thelazia callipaeda eyeworm in naturally infected cats. Methods: Fifteen privately owned cats harboring at least one live adult T. callipaeda were included in the study. Cats were randomly allocated to an untreated control group of seven cats or to a Broadline®-treated group of eight cats. Cats were treated on Day 0; ocular examinations were performed at inclusion and on Days 7 and 14; eyeworms were recovered and counted on Day 14. The primary efficacy assessment was based on group comparison of number of T. callipaeda on Day 14. Results: Seven days after treatment, six of eight treated cats were negative for eyeworm infection per visual examination, and on Day 14 no eyeworms were found in the treated cats while the seven untreated cats were still infected (geometric mean: 1.97). All cats had inflammatory ocular signs at inclusion; on Day 14, five of eight treated cats had recovered while all untreated control cats were still symptomatic. All collected parasites were confirmed to be T. callipaeda by morphology and molecular characterization. Conclusions: A single treatment with Broadline® provided 100% efficacy against feline thelaziosis and improved related ocular inflammation signs. Graphical abstract: [Figure not available: see fulltext.]

    A comprehensive overview on Kratom

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    Kratom (Mitragyna speciosa Korth) is a tropical tree, indigenous to South East Asia. Historically, the plant is locally used as a stimulant, a remedy in traditional medicine and in social context. Imported to Western countries, Kratom is classified as a novel psychoactive substance (NPS). A systematic review of the literature on Mitragyna speciosa and its main constituents was carried by our international multidisciplinary group. Results were qualitatively analysed in three main areas of interest: in-vitro and preclinical data on pharmacology and behavioral effects, laboratoristic techniques for identification/characterization, epidemiological/toxicological reports on humans. At present, there is no systematic data on the prevalence of Kratom use in all the native countries, but it seems to be considerable. In South-East Asia, Kratom, even if banned, might be still considered a better option than other illicit drugs, an alternative opioid treatment, a “natural” remedy with no real social stigma attached to its consumption. In parallel, this ethno-drug seems to be popular in Western countries, largely unregulated, easily available on the Internet. Kratom pharmacology appears to be complex, with many alkaloids involved. The subjective effects in humans are very peculiar and seem to be dose-dependent, ranging from psycho-stimulant to sedative-narcotic. Available data on Kratom suggest caution: this psychoactive plant could exhibit a serious harmful potential. Kratom use seems to be associated with drug dependency, development of withdrawal symptoms, craving, serious adverse effects and life-threatening effects in a multidrug-intoxicating scenario. On the other hand, its anxyiolitic, antidepressant and analgesic properties deserve to be further studied
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