150 research outputs found
Practice parameters for the treatment of colonic diverticular disease: Italian Society of Colon and Rectal Surgery (SICCR) guidelines
The mission of the Italian Society of Colorectal Surgery (SICCR) is to optimize patient care. Providing evidence-based practice guidelines is therefore of key importance. About the present report it concernes the SICCR practice guidelines for the diagnosis and treatment of diverticular disease of the colon. The guidelines are not intended to define the sole standard of care but to provide evidence-based recommendations regarding the available therapeutic options
MIL-53 (Al) and graphene oxide nanocomposites for dye adsorption
Master's Project (M.S.) University of Alaska Fairbanks, 2020Textile manufacturers produce large amounts of wastewater every year as a result of global demand. Waste dyes are highly resilient against physical processes, insoluble in water, and resistant to detergents. Carcinogenic and mutagenic effects are linked to these dyes, making them a large health hazard. Current dye removal methods are highly complex and inefficient. Thus, a new means of removing textile dyes from wastewater is needed. Nanomaterials are one such possibility, since they exhibit traits unique from bulk materials. One key trait is their surface area to volume ratio. Since the materials are so small, they’re almost able to be considered two dimensional in certain instances. A high surface area is closely linked to adsorption potential, making nanomaterials a promising candidate for dye removal. This project has two portions: material synthesis and adsorption testing. Material synthesis sets up the adsorption testing phase by fabricating enough nanomaterials for testing. The nanomaterials used for this project are MIL-53 (Al) and graphene oxide (GO). MIL-53 (Al) and GO were chosen since they exhibit good stability in water and effective geometrical structures for water filtration. Synthesized composites of the two materials varying in mass of GO will be tested as well. Adsorption testing uses slightly acidic (pH 5.6) methyl blue and methyl orange solutions of varying parts per million (PPM) concentrations. The tests examine effects of initial concentration, duration of exposure, and temperature effects on adsorption potential. Nanomaterials reached equilibrium adsorption after 12 hours of mixing. Most materials efficiently removed up to 90% or greater of dye particles in solutions with initial concentrations of 100 PPM for both dye colors. Increased temperatures reduced adsorption potential of nearly all materials tested for both dye colors
Hard macrocells for DC/DC converter in automotive embedded mechatronic systems
A novel configurable DC/DC converter architecture, to be integrated as hard macrocell in automotive embedded systems, is proposed in the paper. It aims at realizing an intelligent voltage regulator. With respect to the state of the art, the challenge is the integration into an automotive-qualified chip of several advanced features like dithering of switching frequency, nested control loops with both current and voltage feedback, asynchronous hysteretic control for low power mode, slope control of the power FET gate driver, and diagnostic block against out-of-range current or voltage or temperature conditions. Moreover, the converter macrocell can be connected to the in-vehicle digital network, exchanging with the main vehicle control unit status/diagnostic flags and commands. The proposed design can be configured to work both in step-up and step-down modes, to face a very wide operating input voltage range from 2.5 to 60 V and absolute range from −0.3 to 70 V. The main target is regulating all voltages required in the emerging hybrid/electric vehicles where, besides the conventional 12 V DC bus, also a 48 V DC bus is present. The proposed design supports also digital configurability of the output regulated voltage, through a programmable divider, and of the coefficients of the proportional-integrative controller inside the nested control loops. Fabricated in 0.35 μm CMOS technology, experimental measurements prove that the IC can operate in harsh automotive environments since it meets stringent requirements in terms of electrostatic discharge (ESD) protection, operating temperature range, out-of-range current, or voltage condition
Effect of two gaps on the flux lattice internal field distribution: evidence of two length scales from muSR in Mg1-xAlxB2
We have measured the transverse field muon spin precession in the flux
lattice (FL) state of the two gap superconductor MgB2 and of the electron doped
compounds Mg1-xAlxB2 in magnetic fields up to 2.8T. We show the effect of the
two gaps on the internal field distribution in the FL, from which we determine
two coherence length parameters and the doping dependence of the London
penetration depth. This is an independent determination of the complex vortex
structure already suggested by the STM observation of large vortices in a MgB2
single crystal. Our data agrees quantitatively with STM and we thus validate a
new phenomenological model for the internal fields.Comment: now in press Phys. Rev. Lett., small modifications required by the
edito
Physicochemical and sensory evaluation of grain-based food
Grain-based food is a staple of the human diet. Whether it is cereals, legumes or pseudocereals, grain-based diets provide nutritional benefits. This can be in the form of macronutrients (starch, fibre, protein, and lipids) and micronutrients (minerals and vitamins), as well as bioactive peptides and phytochemicals [1]. Grains are used to develop bakery products, such as savory (bread, gluten-free bread, crackers, and pasta) and sweet (cakes and muffins) [2] in addition to plant-based beverages (milk alternatives), fermented products (such as yoghurt and fermented paste), extrudates and other snacks [3]. Furthermore, grain-based ingredients offer emulsifying, foaming and thickening abilities [4]. Raw materials include cereals (barley, corn, millet, rice, rye, spelt, wheat), legumes (beans, chickpeas, lentils, peas, and soybeans) and pseudocereals (amaranth, buckwheat, quinoa, and sorghum). The functionalities are numerous, spanning from health to taste. In order to fully exploit the nutritional potential of grain-based foods, consumer acceptance must be achieved. This will guarantee compliance. The acceptability of food can be studied both instrumentally and via sensory science
Management of perforated diverticulitis with generalized peritonitis. a multidisciplinary review and position paper
La diverticolite perforata è una condizione clinica emergente e la sua gestione è impegnativa e ancora dibattuta. Lo scopo di questo documento di posizione era di rivedere criticamente le prove disponibili sulla gestione della diverticolite perforata e della peritonite generalizzata al fine di fornire suggerimenti basati sull'evidenza per una strategia di gestione. Quattro società scientifiche italiane (SICCR, SICUT, SIRM, AIGO), esperti selezionati che hanno identificato 5 temi clinicamente rilevanti nella gestione della diverticolite perforata con peritonite generalizzata che trarrebbero beneficio da una revisione multidisciplinare. Sono state affrontate le seguenti 5 problematiche: 1) Criteri per decidere tra trattamento conservativo e chirurgico in caso di diverticolite perforata con peritonite; 2) Criteri o sistema di punteggio per scegliere l'opzione chirurgica più appropriata quando è confermata la peritonite diffusa 3); La procedura chirurgica appropriata in pazienti emodinamicamente stabili o stabilizzati con peritonite diffusa; 4) La procedura chirurgica appropriata per i pazienti con peritonite generalizzata e shock settico e 5) Terapia medica ottimale in pazienti con peritonite generalizzata da perforazione diverticolare prima e dopo l'intervento chirurgico. Nella diverticolite perforata la chirurgia è indicata in caso di peritonite diffusa o fallimento della gestione conservativa e la decisione di operare non è basata sulla presenza di aria extraluminale. Se la peritonite diffusa è confermata, la scelta della tecnica chirurgica si basa sui risultati intraoperatori e sulla presenza o il rischio di shock settico grave. Ulteriori fattori prognostici da considerare sono lo squilibrio fisiologico, l'età, le comorbidità e lo stato immunitario. Nei pazienti emodinamicamente stabili, la laparoscopia di emergenza presenta vantaggi rispetto alla chirurgia a cielo aperto. Le opzioni includono resezione e anastomosi, procedura di Hartmann o lavaggio laparoscopico. Nella peritonite generalizzata con shock settico, è preferibile un approccio chirurgico aperto. La resezione non restaurativa e / o la chirurgia per il controllo del danno sembrano essere le uniche opzioni praticabili, a seconda della gravità dell'instabilità emodinamica. La gestione medica multidisciplinare dovrebbe essere applicata con gli obiettivi principali di controllare l'infezione, alleviare il dolore postoperatorio e prevenire e / o trattare ileo postoperatorio. In conclusione, la complessità e la diversità dei pazienti con perforazione diverticolare e peritonite diffusa richiede una strategia personalizzata, che preveda un'accurata classificazione dello squilibrio fisiologico, la stadiazione dell'infezione intra-addominale e la scelta della procedura chirurgica più appropriata.Perforated diverticulitis is an emergent clinical condition and its management is challenging and still debated. The aim of this position paper was to critically review the available evidence on the management of perforated diverticulitis and generalized peritonitis in order to provide evidence-based suggestions for a management strategy. Four Italian scientific societies (SICCR, SICUT, SIRM, AIGO), selected experts who identified 5 clinically relevant topics in the management of perforated diverticulitis with generalized peritonitis that would benefit from a multidisciplinary review. The following 5 issues were tackled: 1) Criteria to decide between conservative and surgical treatment in case of perforated diverticulitis with peritonitis; 2) Criteria or scoring system to choose the most appropriate surgical option when diffuse peritonitis is confirmed 3); The appropriate surgical procedure in hemodynamically stable or stabilized patients with diffuse peritonitis; 4) The appropriate surgical procedure for patients with generalized peritonitis and septic shock and 5) Optimal medical therapy in patients with generalized peritonitis from diverticular perforation before and after surgery. In perforated diverticulitis surgery is indicated in case of diffuse peritonitis or failure of conservative management and the decision to operate is not based on the presence of extraluminal air. If diffuse peritonitis is confirmed the choice of surgical technique is based on intraoperative findings and the presence or risk of severe septic shock. Further prognostic factors to consider are physiological derangement, age, comorbidities, and immune status. In hemodynamically stable patients, emergency laparoscopy has benefits over open surgery. Options include resection and anastomosis, Hartmann’s procedure or laparoscopic lavage. In generalized peritonitis with septic shock, an open surgical approach is preferred. Non-restorative resection and/or damage control surgery appear to be the only viable options, depending on the severity of hemodynamic instability. Multidisciplinary medical management should be applied with the main aims of controlling infection, relieving postoperative pain and preventing and/or treating postoperative ileus. In conclusion, the complexity and diversity of patients with diverticular perforation and diffuse peritonitis requires a personalized strategy, involving a thorough classification of physiological derangement, staging of intra-abdominal infection and choice of the most appropriate surgical procedure
Nonequilibrium superconducting thin films with sub-gap and pair-breaking photon illumination
We calculate nonequilibrium quasiparticle and phonon distributions for a
number of widely-used low transition temperature thin-film superconductors
under constant, uniform illumination by sub-gap probe and pair-breaking signal
photons simultaneously. From these distributions we calculate
material-characteristic parameters that allow rapid evaluation of an effective
quasiparticle temperature using a simple analytical expression, for all
materials studied (Mo, Al, Ta, Nb, and NbN) for all photon energies. We also
explore the temperature and energy-dependence of the low-energy quasiparticle
generation efficiency by pair-breaking signal photons finding in the limit of thick films at low bath temperatures that is
material-independent. Taking the energy distribution of excess quasiparticles
into account, we find as the bath temperature approaches the
transition temperature in agreement with the assumption of the two-temperature
model of the nonequilibrium response that is appropriate in that regime. The
behaviour of with signal frequency scaled by the superconducting energy
gap is also shown to be material-independent, and is in qualitative agreement
with recent experimental results. An enhancement of in the presence of
sub-gap (probe) photons is shown to be most significant at signal frequencies
near the superconducting gap frequency and arises due to multiple photon
absorption events that increase the average energy of excess quasiparticles
above that in the absence of the probe.This is the author accepted manuscript. The final version is available via IOP Science at http://iopscience.iop.org/0953-2048/28/5/054002/
B NMR study of pure and lightly carbon doped MgB superconductors
We report a B NMR line shape and spin-lattice relaxation rate
() study of pure and lightly carbon doped MgBC for
, 0.02, and 0.04, in the vortex state and in magnetic field of 23.5 kOe.
We show that while pure MgB exhibits the magnetic field distribution from
superposition of the normal and the Abrikosov state, slight replacement of
boron with carbon unveils the magnetic field distribution of the pure Abrikosov
state. This indicates a considerable increase of with carbon doping
with respect to pure MgB. The spin-lattice relaxation rate
demonstrates clearly the presence of a coherence peak right below in pure
MgB, followed by a typical BCS decrease on cooling. However, at
temperatures lower than K strong deviation from the BCS behavior is
observed, probably from residual contribution of the vortex dynamics. In the
carbon doped systems both the coherence peak and the BCS temperature dependence
of weaken, an effect attributed to the gradual shrinking of the
hole cylinders of the Fermi surface with electron doping.Comment: 8 pages, 6 figures, submitted to Phys. Rev.
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