Electronic nanodevices based on self-assembled metalloproteins

A key challenge of the current research in nanoelectronics is the realization of biomolecular devices. The use of electron-transfer proteins, such as the blue copper protein azurin (Az), is particularly attractive because of their natural redox properties and self assembly capability. We present in this work our results about the fabrication, characterization and modeling of devices based on such redox protein. The prototypes of biomolecular devices operate in the solid state and in air . The charge transfer process in protein devices can be engineered by using proteins with different redox centers (metal atoms) and by controlling their orientation in the solid state through different immobilization methods. A biomolecular electron rectifier has been demonstrated by interconnecting two gold nanoelectrodes with an azurin monolayer immobilized on SiO2. The device exhibits a clear rectifying behavior with discrete current steps in the positive wing of the current–voltage curve, which are ascribed to resonant tunnelling through the redox active center. On the basis of these results we have designed an azurin-based transistor. The three terminal device exhibits an ambipolar behavior as a function of the gate bias, thus opening the way to the implementation of a new generation of logic architecture, such as fully integrated biomolecular logic gate

Guillain‐Barré syndrome: A comprehensive review

Guillain‐Barré syndrome (GBS) is a potentially devastating yet treatable disorder. A classically postinfectious, immune‐mediated, monophasic polyradiculoneuropathy, it is the leading global cause of acquired neuromuscular paralysis. In most cases, the immunopathological process driving nerve injury is ill‐defined. Diagnosis of GBS relies on clinical features, supported by laboratory findings and electrophysiology. Although previously divided into primary demyelinating or axonal variants, this dichotomy is increasingly challenged, and is not endorsed by the recent European Academy of Neurology (EAN)/Peripheral Nerve Society (PNS) guidelines. Intravenous immunoglobulin and plasma exchange remain the primary modalities of treatment, regardless of the electrophysiological subtype. Most patients recover, but approximately one‐third require mechanical ventilation, and 5% die. Disease activity and treatment response are currently monitored through interval neurological examination and outcome measures, and the potential role of fluid biomarkers is under ongoing scrutiny. Novel potential therapies for GBS are being explored but none have yet modified clinical practice. This review provides a comprehensive update on the pathological and clinical aspects of GBS for clinicians and scientists

Budgetary policy in the countries of the European Union in the 1990s

The paper examines the steps taken in the EU countries during the 1990s to adjust the public finances, describing their main characteristics on the basis of the measures’ impact on expenditure and revenue. It also attempts to estimate the possible “non-Keynesian” effects of the budgetary measures adopted and of their composition on economic activity. These effects supposedly emerge via expectation regarding disposable income and/or via the competitiveness of the single economies. Alongside cases, including that of Italy, in which the traditional “Keynesian” effects appear to have dominated, there are cases in which deficit reduction has been accompanied by satisfactory macroeconomic results. The evidence does not refute the thesis that, in an appropriate economic policy context, suitably designed budgetary tightening can generate expansionary effects on private consumption and production.budgetary policy, European Union

Projecting the nanoworld: Concepts, results and perspectives of molecular electronics

A bottom-up approach is a promising alternative to build nanodevices and/or nanomachines starting from molecular building blocks. The idea of molecular electronics comes from a farsighted paper by Aviram and Ratner, predicting that single molecules with a donor–spacer–acceptor structure would have rectifying properties when placed between two electrodes. Today, molecular electronics is emerging as an alternative to Si-nanoelectronics for building integrated devices. This review aims to give an overview of this emerging field, analysing the concepts, the key results and the perspectives

Tassazione e costo del lavoro nei paesi industriali

Il lavoro analizza gli effetti sul costo del lavoro determinati dal livello e dalla composizione del prelievo fiscale su tale fattore produttivo. Esso fornisce in particolare una valutazione quantitativa della traslazione dellÂ’imposta sui costi con riferimento a quattordici paesi industriali nel periodo 1980-1996. I risultati dellÂ’analisi econometrica sono i seguenti; (i) il livello e la variazione del prelievo tributario e contributivo hanno effetti statisticamente significativi sul costo del lavoro; (ii) non vi è riscontro per lÂ’ipotesi dellÂ’invarianza dellÂ’incidenza del prelievo; lÂ’imposta sul reddito e i contributi sociali a carico del datore di lavoro hanno unÂ’influenza più marcata sui costi rispetto ai contributi a carico del lavoratore; (iii) la traslazione dellÂ’imposta è più forte in quei paesi europei caratterizzati da un sistema di contrattazione salariale intermedio tra completa decentralizzazione e piena centralizzazione. Alla luce di questi risultati, il lavoro fornisce infine una valutazione dei provvedimenti volti a ridurre il prelievo sul lavoro assunti in Italia negli ultimi anni. Tali provvedimenti mirano ad abbassare le due componenti del prelievo - imposta sul reddito e contributi sociali a carico del datore di lavoro - che esercitano alla luce dellÂ’analisi econometrica un effetto maggiore sul costo del lavoro.

A sustainability-oriented methodology to compare production strategies: The case of AM-based remanufacturing

The implementation of sustainability principles is becoming fundamental for companies, also for creating added value in the production processes. Production managers should not consider only the economic-financial aspects in their decisions, but also the environmental and social implications to extend the benefits to all current and future world populations. This vision requires to develop and apply sustainability-oriented methodologies to compare alternative production strategies. This paper contributes to addressing this problem by proposing a methodology that allows comparing different production strategies by considering their sustainable impact, starting with the definition of their processes. An aggregated sustainability index has been designed for this purpose. Thus, the paper contributes to the literature on the evaluation of sustainability through the development of a methodology, which can be used by the practitioners as a decision support tool to identify the most sustainable production strategy according to the objective of the company and the specific production process considered. Then, the proposed methodology has been applied to compare two different production strategies, i. e., AM-based remanufacturing and the production of new components. A simulation model has been implemented to reproduce the behaviour of the two competing production strategies. Although the results depend on the utilized data, this application showed that it is possible to distinguish different areas of convenience for each strategy. Moreover, findings revealed that the sustainability of the production strategies is strictly connected to the adopted technology and the importance given to the economic, environmental and social aspects by the company

Nanotechnology approaches to self-organized bio-molecular devices

Abstract In this paper we briefly describe new strategies to exploit self-assembled solid-state biomolecular materials as active elements of electronic devices. Two basically different approaches are proposed: a top-down approach, where biomolecular semiconductors consisting of DNA basis are self-organized and interconnected by planar metallic nanopatterns, and a bottom-up approach, where single or ordered matalloproteins are immobilized in a nanocircuit realizing a hybrid covalently bound biologic–inorganic system. The transport characteristics of different devices such as diodes, photodetectors and metal–semiconductor–metal structures will be described

The effect of 1-methylcyclopropene (1-MCP) application before and after cutting on the shelflife extension of fresh-cut tomatoes

[ENG] Exposing partially ripe fruit to 1-methylcyclopropene (1-MCP) before or after cutting may be a useful supplement to proper temperature and relative humidity management for maintaining quality of fresh-cut fruit products. In this study tomato fruits were exposed to 0.5 ppm of 1-MCP for 24 hours, while tomato slices were exposed to the same concentration of 1-MCP for 6 hours. Untreated slices were used as control. Initially and after 3, 7, and 9 days of storage at 5 °C the following quality attributes were evaluated: flesh and skin color, firmness, total soluble solids content, titratable acidity and weight loss. In addition, respiration rate and ethylene production were measured. Fresh-cut tomato slices treated with 0.5 ppm of 1-MCP before cutting showed higher firmness retention than untreated slices, while slices treated after cutting showed an intermediate firmness value. Color development was delayed in both 1-MCP treated samples, which presented higher skin and flesh hue angle value compared with untreated slices. The initial decrease in skin hue angle value was reduced in slices treated either before or after cutting, while those treated after cutting showed the highest value of hue angle of the flesh. Application of 1-MCP did not affect the respiration rate, but slowed down C2H4 production in slices treated after cutting, compared to slices from untreated tomatoes. No significant effect of 1-MCP treatment was observed on titratable acidity, while for soluble solids content slices treated after cutting showed a value significantly higher than untreated slices. Application before processing resulted most effective for firmness retention, while all other effects were more visible when application followed cutting. [SPA] La exposición de tomate parcialmente maduro a 1-metilciclopropeno (1-MCP) antes o después del corte puede representar un método útil, sumado al control de la temperatura y humedad, para mantener la calidad del producto mínimamente procesado. En este estudio los tomates enteros han sido expuestos a 0,5 ppm de 1-MCP durante 24 horas, mientras las rodajas se expusieron a la misma concentración durante 6 horas. Como control se utilizaron rodajas de tomate no tratadas. Inicialmente y tras 3, 7, y 9 días de conservación a 5 ºC se evaluaron los siguientes atributos cualitativos: color (piel y pulpa), firmeza, contenido en sólidos solubles, acidez titulable y pérdida de peso. Además, se midieron la tasa respiratoria y de producción de etileno. Las rodajas de tomate tratadas con 0,5 ppm de 1-MCP antes del corte mostraron mayor mantenimiento de firmeza que las no tratadas, mientras que las rodajas tratadas después del corte han mostrado un valor intermedio de firmeza. El desarrollo del color se ha ralentizado en los dos tratamientos realizados con 1-MCP; las rodajas tratadas han mostrado un mayor valor del ángulo de tinta de la piel y de la pulpa respecto al control. La disminución inicial del ángulo de tinta de la piel se redujo en los dos tratamientos, mientras las rodajas tratadas después del corte han mostrado un mayor valor del ángulo de tinta de la pulpa. La aplicación del 1-MCP no ha afectado a la actividad respiratoria pero ha disminuido la emisión de etileno en rodajas tratadas después del corte respecto a las rodajas no tratadas con 1-MCP. No se ha observado efecto significativo del tratamiento sobre la acidez titulable, el contenido de sólidos solubles de las rodajas tratadas después del corte se ha mostrado más alto que el control. La aplicación del 1-MCP antes y después del procesado ha resultado más efectiva para el mantenimiento de la firmeza y del color, respectivamente