Extending ballistic graphene FET lumped element models to diffusive devices

In this work, a modified, lumped element graphene field effect device model is presented. The model is based on the "Top-of-the-barrier" approach which is usually valid only for ballistic graphene nanotransistors. Proper modifications are introduced to extend the model's validity so that it accurately describes both ballistic and diffusive graphene devices. The model is compared to data already presented in the literature. It is shown that a good agreement is obtained for both nano-sized and large area graphene based channels. Accurate prediction of drain current and transconductance for both cases is obtained

Digital Pathology In Italy: Preliminary Results From A National Survey

Introduction/ Background Digital pathology has been around since many years now, but it is still not fully integrated in work routine. The Italian Society of Pathology and CytoDiagnostics  (SIAPEC)  contributed  to   its   development at national level, and is willing to stimulate better collaboration and sharing for the aims of continuing education and training. For this, a common infrastructure for hosting digital slides could be useful. For this, SIAPEC, in collaboration with theUniversityofUdine, decided to investigate the current status of digital pathology inItaly, to foresee possible development paths. Aims The aim of the present work is to present preliminary results on digital pathology diffusion in the Italian pathology institutes, and to understand if there is interest and need for a common infrastructure for continuing education and training in pathology through digital slides.   Methods A survey has been developed in two formats (online through Google Forms and as Word file) to ask 24 questions to Pathology laboratory Chairs. Recipients were contacted through email and addressed to both versions. The survey included questions on the availability of slide scanners, on the organization of slide/image archives (if any), on the aims of the archives, on the technical availability of slides and on their anonymization, and finally on the foreseen advantages of digital pathology. The survey started in January 2016.   Results Of the 241 recipients (i.e., Pathology Institutes inItaly), 48 (20%) answered the survey at the time of submission. 14 Institutes (39%) declared to own at least one scan ner. However, all the others have traditional tools for image acquisition: cameras on the microscope, macroscopic cameras, digital microscopes, fluorescence microscopes with acquisition tools, confocal/ deconvolution  microscopes. 17 Institutes manage organized slide or image archives, however in all but 2 cases they are not integrated with the LIS. Who has an archive, typically stores 11-50 slides or images per month, with a total number of cases being between 500 and 1000.The most frequent aims of the archive are Education (7), Teleconsultation (6), Image analysis (6). Answers to technical questions (image formats, Z-axis scanning) were less frequent than others: details are not always known to pathologists. About half of the Institutes anonymize the slides by covering the tag, the others not. When asked about the possible advantages of digital pathology, Italian pathologists seems to be conservative. In fact, the most chosen application is second opinion (44), followed by online case development for scientific aims (29), and education (27). Diagnostic routine is chosen only 14 times, while the possibility of integration with other clinical data and images is chosen by 15 only. However, in general digital pathology seems not yet applied in diagnostic routine, but rather relegated to ancillary roles. This fact is also supported by the low number of high throughput scanners owned by Institutes: only 3 declared having large slide feeders (>100 slides). At the time of the congress updated results will be provided

D2 or non D2-lymphadenectomy in gastric cancer

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Postharvest Ozone Fumigation of Grapes (cv Sangiovese) Differently Affects Volatile Organic Compounds and Polyphenol Profiles of Berries and Wine

Consumers are more and more oriented towards the purchase of safer food and beverages, which is pushing the wine sector to find alternatives to the use of sulfur dioxide. Ozone (O3) is already applied in the wine industry to produce sulfur dioxide-free wines through the patented method Purovino®. The aim of this two-year study was that of evaluating whether the postharvest treatment of grapes with ozone affects volatile organic compounds (VOCs) and polyphenol profile in berries, and in turn, wine composition. Grape bunches (Vitis vinifera L.) of cv Sangiovese were fumigated overnight with gaseous ozone (max 20 g·h−1 with 6% w.w−1 of ozone) in a cold room at 4°C (±0.5). After treatment, grapes were processed into wine. In grapes, ozone treatments increased total polyphenol and flavonoid content and upregulated specific genes (phenylalanine ammonia lyase, VvPAL, flavanol synthase 1, and VvFLS1) involved in polyphenol biosynthesis. Wine obtained from ozone-treated grapes had higher flavanol content than the control. Fumigation only slightly affected the different VOC classes of grapes and wine, including aroma compounds derived from the lipoxygenase (LOX) pathway. Although a season-dependent effect was observed, results showed that postharvest ozone treatments applied to avoid the use of sulfur dioxide introduced limited but, in general, positive modifications to grape and wine composition. This information provides assurance to winemakers that the maintenance of wine quality and typicity will be guaranteed when using ozone treatments

Local and Distributed fMRI Changes Induced by 40 Hz Gamma tACS of the Bilateral Dorsolateral Prefrontal Cortex: A Pilot Study

Over the past few years, the possibility of modulating fast brain oscillatory activity in the gamma (γ) band through transcranial alternating current stimulation (tACS) has been discussed in the context of both cognitive enhancement and therapeutic scenarios. However, the effects of tACS targeting regions outside the motor cortex, as well as its spatial specificity, are still unclear. Here, we present a concurrent tACS-fMRI block design study to characterize the impact of 40 Hz tACS applied over the left and right dorsolateral prefrontal cortex (DLPFC) in healthy subjects. Results suggest an increase in blood oxygenation level-dependent (BOLD) activity in the targeted bilateral DLPFCs, as well as in surrounding brain areas affected by stimulation according to biophysical modeling, i.e., the premotor cortex and anterior cingulate cortex (ACC). However, off-target effects were also observed, primarily involving the visual cortices, with further effects on the supplementary motor areas (SMA), left subgenual cingulate, and right superior temporal gyrus. The specificity of 40 Hz tACS over bilateral DLPFC and the possibility for network-level effects should be considered in future studies, especially in the context of recently promoted gamma-induction therapeutic protocols for neurodegenerative disorders. © 2022 Lucia Mencarelli et al

Graphene-based Electronically Tuneable Microstrip Attenuator

This paper presents the design of a graphene-based electronically tuneable microstrip attenuator operating at a frequency of 5 GHz. The use of graphene as a variable resistor is discussed and the modelling of its electromagnetic properties at microwave frequencies is fully addressed. The design of the graphene-based attenuator is described. The structure integrates a patch of graphene, whose characteristics can range from being a fairly good conductor to a highly lossy material, depending on the applied voltage. By applying the proper voltage through two high-impedance bias lines, the surface resistivity of graphene can be modified, thereby changing the insertion loss of the microstrip attenuator

Bacterial Populations Related to Gerbera (Gerbera jamesonii L.) Stem Break

Bacterial distribution, both external (epiphytic) and internal (endophytic), on Gerbera jamesonii L. cv. Provence and its relationship to gerbera stem break and ethylene production were investigated. The greatest number of epiphytic bacteria was found at capitulum level and 20 cm below. Three genera of bacteria were identified: Acinetobacter, Bacillus and Pantoea. A silver-nitrate solution greatly reduced ethylene production in cut flowers. The use of acid fuchsin solution revealed an occlusion of the xylem vessels, probably due to bacterial cells. The bacteria Acinetobacter, Pantoea and Bacillus appeared to be involved in stem break once their populations reached 105 cfu g-1 of stem tissue

Graphene-based waveguide resonators for submillimeter-wave applications

Utilization of graphene covered waveguide inserts to form tunable waveguide resonators is theoretically explained and rigorously investigated by means of full-wave numerical electromagnetic simulations. Instead of using graphene-based switching elements, the concept we propose incorporates graphene sheets as parts of a resonator. Electrostatic tuning of the graphene surface conductivity leads to changes in the electromagnetic field boundary conditions at the resonator edges and surfaces, thus producing an effect similar to varying the electrical length of a resonator. The presented outline of the theoretical background serves to give phenomenological insight into the resonator behavior, but it can also be used to develop customized software tools for design and optimization of graphene-based resonators and filters. Due to the linear dependence of the imaginary part of the graphene surface impedance on frequency, the proposed concept was expected to become effective for frequencies above 100 GHz, which is confirmed by the numerical simulations. A frequency range from 100 GHz up to 1100 GHz, where the rectangular waveguides are used, is considered. Simple, all-graphene-based resonators are analyzed first, to assess the achievable tunability and to check the performance throughout the considered frequency range. Graphene–metal combined waveguide resonators are proposed in order to preserve the excellent quality factors typical for the type of waveguide discontinuities used. Dependence of resonator properties on key design parameters is studied in detail. Dependence of resonator properties throughout the frequency range of interest is studied using eight different waveguide sections appropriate for different frequency intervals. Proposed resonators are aimed at applications in the submillimeter-wave spectral region, serving as the compact tunable components for the design of bandpass filters and other devices