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Gastro-esophageal reflux disease (GERD) is a pathological entity in which the mixture of gastric contents (with low pH because of the high content of HCl acid) and biliary juice (rich in proteolytic enzymes like pepsin and trypsin) causes lesions on the mucosa lining the esophagus. A higher prevalence of GERD was discovered in patients who had a total laryngectomy. Concerning laryngectomies with tracheo-esophageal speaking valves, it has been demonstrated that GERD is an independent risk factor for failure of this method of speech rehabilitation. The authors performed an analysis of English language articles found following a search of the major medical scientific databases (NCBI®, EMBASE®, Cochrane®) containing the following keyword string: vocal prosthesis, total laryngectomy, GERD, acid reflux, tracheo-esophageal fistula, failure. Studies showed that exposure to the protelolytic enzymes from the reflux juice increases the diameter of the tracheo-esophageal fistula and permits local granulation tissue to form. Progressively, the increasing fistula diameter leads to complications ranging from microaspiration of liquids and saliva to speaking valve expulsion or ingestion and temporary incapacity of oral feeding. Medical therapy in the postoperative period as well as long-term (6 months or more) correction of GERD (PPI therapy, H2 blockers, prokinetics) is also demonstrated to reduce the complication rate in this category of patients. GERD has a high prevalence in the total laryngectomy population of patients and it has multiple etiologic factors. In patients with tracheoesophageal vocal prostheses, GERD causes an increase in the fistula diameter – with important consequences that affect the patient's quality of life - his ability to phonate and his ability to swallow. These complications come with added costs because of the need to more frequently change the vocal prostheses with ones increasing in diameter, as well as multiple hospitalizations (even surgery to recalibrate or close the tracheo-esophageal fistula). Recognizing and treating this condition therefore decreases the risk of complications following vocal prosthesis speech rehabilitation.

In this work, thermoelectric properties of the nanocomposite materials produced via ball milling followed by spark plasma sintering from In0.2Yb0.2Co4Sb12 double filled skutterudite (SKT) with silicon and tungsten carbide inclusions are investigated. The nanocomposites with low volume ratios of β-SiC and α-WC have a significantly increased power factor, while the lattice thermal conductivity is lowered only for β-SiC composites. The power factor enhancement in α-WC/SKT composite compensates the increase of its thermal conductivity, and as a consequence, the maximum value of the figure of merit, 0.97, is attained for 0.33 v% α-WC at 450 °C, with 15% higher than that of the simple skutterudite sample.

For DEMO fusion reactor an expected heat flux of about 10 MW/m 2 should be extracted by the divertor which will have, most likely, an armour part made of W and a following heat sink part made of Cu or ODS Cu alloy. Unfortunately, for these materials the optimum operating temperature windows do not overlap. Thermal barrier materials are interface materials included in such components, aiming to keep the temperatures of both armour and heat sink parts in the corresponding operating windows, and to mitigate the effects of their different thermomechanical properties. Here we propose a simple spark plasma sintering route to create Cu-based composites with a high content (10–40 vol%) of various dispersed materials (Al or Y oxides, C, SiC), allowing a fine tuning of the content and a large pool of predefined shapes and dimensions. The resulting specimens can be further joined to armour and heatsink components via a similar electrical field assisted technology. Micro-structural and thermal properties are investigated for these materials allowing to select the most suited materials in view of their thermal conductivity and thermal expansion coefficients.

In this paper, we investigate the influence of Cu, Co, and Al substitutions on the transport properties, and in particular, the magnetoresistive effect in Ni–Fe–Ga ferromagnetic shape memory alloys (FSMAs) prepared as ribbons by melt spinning method and subjected to different thermal treatments. X-ray diffraction, differential scanning calorimetry, magnetometry, and magnetoresistive characterizations were performed. In the range of the martensitic transformation (MT), different FSMA compositions show a rich spectrum of different behaviors. For one of the compositions (Ni52Fe20Co2Ga23Al3), the magnetoresistance (MR) showed a local minimum or, on the contrary, a local maxima of reduced amplitude on cooling, in the range of the MT, depending on the performed thermal treatments. In the same composition, by replacing one Al atom with a Co one, no local extremes are seen, the alloy having a concomitant magneto-structural transition. When the magnetic field was varied, the MR showed a nonmonotonic variation in the martensite phase for some compounds, possibly due to the dynamics of the martensite variants realignment. From the studied compositions, the highest MR found on the MT of −9% for 5 T is for Ni50Fe20Ga27Cu3.

In the case of DEMO fusion reactor, the divertor should be able to extract a steady heat flux of about 10 MW/m2. A promising concept is the W-monoblock which should be connected to a CuCrZr or an advanced Cu ODS alloy pipe passing through the W component. Taking into account the optimum operating temperature windows for W and existing Cu-based alloys and the thermal expansion coefficients mismatch of these two materials, a “thermal barrier” interface material is inserted in between in order to mitigate the thermal stresses and to optimize the heat flow through divertor components. In this work we investigate the feasibility to realize such divertor components using materials produced by FAST (field assisted sintering technology). This powder metallurgy technique was used firstly to produce W or W-based composites and the thermal barriers in an almost final shape and then to join the materials in realistic divertor mock-ups. The thermal barrier materials are various Cu-based composites which are included both as single material or as functionally graded components. The interface quality between different materials is investigated by scanning electron microscopy and the heat flow through components is evaluated using simulations.

In this paper, we present a modeling framework suited for the theoretical study of electrolyte-gated organic thin-film transistors. Employing a novel, fully self-consistent, coupled Poisson–Boltzmann/drift-diffusion simulator, we analyze the response of biosensors for varying bias conditions and ion concentrations in the electrolyte. Our model considers the diffusive nature of ions in the electrolyte region, the formation of a Helmholtz layer at the electrolyte/organic semiconductor interface and the particular charge transport mechanisms of organic semiconductors, such as field-dependent mobility and the presence of defect states. We calibrate our model on a set of current–voltage measurements for a fabricated device. Once validated, our simulation model offers useful insights in the underlying physics and helps us quantify the impact of the electrolyte solution on the surface potential at the electrolyte/semiconductor interface. A sensitivity analysis is performed to determine the inaccuracy of simpler models, such as the Helmholtz approximation, on the response of our biosensor. Improving our understanding of the working principle and charge transport in such novel electrolyte-gated Organic Thin Film Transistors is an indispensable step toward performance optimization and can pave the way for the design of new, more sensitive biosensor devices.

Waves and shocks traveling through the solar chromospheric plasma are influenced by its partial ionization and weak collisional coupling, and may become susceptible to multi-fluid effects, similar to interstellar shock waves. In this study, we consider fast magneto-acoustic shock wave formation and propagation in a stratified medium, that is permeated by a horizontal magnetic field, with properties similar to that of the solar chromosphere. The evolution of plasma and neutrals is modeled using a two-fluid code that evolves a set of coupled equations for two separate fluids. We observed that waves in neutrals and plasma, initially coupled at the upper photosphere, become uncoupled at higher heights in the chromosphere. This decoupling can be a consequence of either the characteristic spatial scale at the shock front, that becomes similar to the collisional scale, or the change in the relation between the wave frequency, ion cyclotron frequency, and the collisional frequency with height. The decoupling height is a sensitive function of the wave frequency, wave amplitude, and the magnetic field strength. We observed that decoupling causes damping of waves and an increase in the background temperature due to the frictional heating. The comparison between analytical and numerical results allows us to separate the role of the nonlinear effects from the linear ones on the decoupling and damping of waves.

Different types of SiC–W composites have been realized by spark plasma sintering in a single step process starting with beta SiC nanometric powder, W nanometric and micrometric sized powders, and W foils. SEM, EDX, XRD and X-ray tomography have been used to analyze the sample morphology while the thermal properties of the resulting materials have been investigated up to 1000 °C using a LFA thermal analyzer. The results show the possibility to produce dense W–SiC composites, with enhanced thermal conductivity using a relatively simple route.

In this paper, we investigate the dynamic response of two different bulk heterojunction organic photodetectors over a large illumination and frequency range. To our knowledge, there is no similar study that includes the nW/cm2 regime. Photocurrent transient measurements reveal that the interlayer at the hole-extracting electrode is critical for the device performance under ultralow illumination. Furthermore, we observe a nonlinear cutoff frequency behavior over the illumination range, which we attribute to interface-related phenomena. We perform a detailed simulation study of the transient response for the measured samples. Making use of a drift diffusion model that also takes into account charge trapping and detrapping effects, both in bulk and at material interfaces, we are able to successfully reproduce the measured transients. Based on our simulations, we propose an explanation for this effect: it can be attributed to the interplay between the potential landscape seen by the charge carriers and to the presence of a large concentration of interface trap states, as well as of fixed interface charges. The importance of smart interface engineering as a key factor for device optimization is also highlighted.

Important advances in the development of magnetic manipulation devices have been recorded over the last few years and promising experimental results have been presented. In this article we first perform a detailed analysis on one of most widely used magnetic actuators, namely a planar microcoil. Key parameters that affect the performance of the actuator are identified and our results are in accordance with measured data. Making use of these findings, a lab-on-a-chip system is proposed, that also integrates a novel electronic sensing concept for live monitoring of its activity. Possible applications of this system include highly selective bioseparation or the possibility to manipulate and assemble marked particles with great precision.

Four Fe–Mn–Si alloys, Fe 62 Mn 32 Si 6 , Fe 62 Mn 20 Si 5 Cr 8 Ni 5 , Fe 62 Mn 16 Si 5 Cr 12 Ni 5 and Fe 65 Mn 9 Si 7 Cr 10 Ni 9 , were obtained by the melt-spinning method. The samples were structurally, magnetic and shape memory effect (SME) investigated, both “as quenched” and thermally treated. The Mn-rich compositions show different phase, magnetic behavior and SME in comparison with Mn-poor compositions. The thermal treatments generate transformation between the two existing majority phases (α and γ), related magnetization and SME behavior. The features are derived from the corroboration of structural, magnetic interaction and magnitude of SME data.

In this paper we consider, and reject, Harold Langsam’s defenceof the Theory of Appearing, in this journal (1997), in the faceof three standard arguments against it. These arguments are:the argument from hallucination; the argument from the samecause-same effect principle; and the argument from perceptualtime-gap.

Radical neck dissection is a concept that was presented in 1906 by GW Crile and suffered constant improvement ever since. The surgical oncology procedure included the resection of the internal jugular vein, the sternocleidomastoid muscle, and the submandibular gland and the spinal accessory nerve. Deformities and impairment in the functionality of different regions of the neck and scapular regions have great implications on the quality of life of the patients who undergo such a procedure. Modifications to the radical neck dissection were made in the attempt to maintain the efficacy of the surgical oncology therapy. The authors try to assess the functional implications of radical neck dissection and the impact on the quality of life for patients with head and neck neoplasia.

Cervical esophageal cancer and hypopharyngeal cancer represent a major diagnostic issue in early stages, considering the fact that the implication of both cervical esophageal and hypopharyngeal cancers shows a poor prognostic from the very beginning. Positive diagnosis can only be made after histopathological analysis and immunohistochemical analysis in addition. The bioptic material is sampled by rigid endoscopy this being the only viable method of assessing data on the tumor prior to the surgery. As much as 95% of tumors located at this site are epidermoid carcinomas with different staging and characteristics, other types of tumors being adenocarcinomas, lymphomas, etc. Several risk factors influence the biology of this site thus inflicting both cellular and molecular modifications that are the origin of cancer development.

Gallstone ileus represents a rare complication (0,3-0,5%) of a serious, but common disease-gallstones, which affect around 10% of the population in the USA and Western Europe. Associated diseases (usually severe), elderly patients, delayed diagnosis and therapy due to late presentation to the hospital, account for the morbidity and mortality rates described in literature. We present the case of a patient with partial colon obstruction due to a large gallstone that was “lost” during an emergency laparoscopic cholecystectomy. The calculus eroded the intestinal wall, partially occluding the lumen, triggering recurrent Kerwsky-like, subocclusive episodes. The intraperitoneal abscess has spontaneously drained through the subhepatic drain and once the tube has been removed, a persistent intermittent fistula became obvious.