Superior Mesenteric Artery First Approach for Minimally Invasive Pancreaticoduodenectomy: A Step-By-Step Surgical Technique Video.

Introduction: In the past decade, minimally invasive pancreaticoduodenectomy has been gaining interest. However, minimally invasive pancreaticoduodenectomy remains technically challenging and is associated with a steep learning curve. Additionally, the operating surgeon should be cognizant of replicating the same oncological steps as observed in the typical open approach.

Terahertz Characterization of Lead-Free Dielectrics for Different Applications.

In this spotlight on applications, we describe our recent progress on the terahertz (THz) characterization of linear and nonlinear dielectrics for broadening their applications in different electrical devices. We begin with a discussion on the behavior of dielectrics over a broadband of frequencies and describe the main characteristics of ferroelectrics, as they are an important category of nonlinear dielectrics. We then move on to look at the influence of point defects, porosities, and interfaces, including grain boundaries and domain walls, on the dielectric properties at THz frequencies.

Structural Evolution in BiNbO.

The sequence of transitions between different phases of BiNbO has been thoroughly investigated and clarified using thermal analysis, high-resolution neutron diffraction, and Raman spectroscopy. The theoretical optical phonon modes of the α-phase have been calculated. Based on thermoanalytical data supported by density functional theory (DFT) calculations, the β-phase is proposed to be metastable, while the α- and γ-phases are stable below and above 1040 °C, respectively.

Shape and Temperature Expansion of Free Volume Holes in Some Cured Polybutadiene-Polyisoprene Rubber Blends.

The free volume fraction of a macromolecular structure can be assessed theoretically by using a suitable model; however, it can also be evaluated from experimental data obtained from dilatometry and positron annihilation lifetime spectra. In this second case, a regular geometry of the sub-nanometric cavities forming the free volume has to be assumed, although in fact they are irregularly shaped. The most popular approach is to guess spherical holes, which implies an isotropic growth of these last with temperature.

Bioinspired Multiresonant Acoustic Devices Based on Electrospun Piezoelectric Polymeric Nanofibers.

Cochlear hair cells are critical for the conversion of acoustic into electrical signals and their dysfunction is a primary cause of acquired hearing impairments, which worsen with aging. Piezoelectric materials can reproduce the acoustic-electrical transduction properties of the cochlea and represent promising candidates for future cochlear prostheses. The majority of piezoelectric hearing devices so far developed are based on thin films, which have not managed to simultaneously provide the desired flexibility, high sensitivity, wide frequency selectivity, and biocompatibility.

High Thermoelectric Performance in SnTe Nanocomposites with All-Scale Hierarchical Structures.

SnTe has attracted considerable attention as an environmentally friendly thermoelectric material. The thermoelectric figure of merit ZT value is related to low thermal conductivity that can be successfully realized using fabrication of nanostructures. However, the practical realization of SnTe nanostructured composites is often limited by long reaction time, low yield, and aggregation of nanoparticles.

Hypnosis and learning: Pilot study on a group of students.

Background Milton Erickson was the first to introduce hypnosis as a form of therapy during the post-war period. Numerous studies have evaluated the effects of hypnosis on memory, focusing principally on post-hypnotic amnesia, post-hypnotic hypermnesia, faux memories and learning growth. The aim of the present study was to determine if hypnosis can influence visual-spatial memory by increasing its performance and learning; to do this, we chose to utilise the Corsi Test (backward and forward).

Room temperature magnetoelectric coupling in intrinsic multiferroic Aurivillius phase textured ceramics.

Spark plasma sintering was employed in order to obtain textured Aurivillius phase ceramics that simultaneously exhibit ferroelectric and ferromagnetic properties at room temperature. The sintered multiferroics are layer-structured, nearly single-phase materials. Although a small amount of the secondary phase consisting of magnetic Co and Fe was detected by SEM/EDX, a majority of the observed ferromagnetic behaviour was attributed to the Aurivillius phase BiLaTiFeCoO based on the observed magnetic anisotropy.

Tuning the electrocaloric enhancement near the morphotropic phase boundary in lead-free ceramics.

The need for more energy-efficient and environmentally-friendly alternatives in the refrigeration industry to meet global emission targets has driven efforts towards materials with a potential for solid state cooling. Adiabatic depolarisation cooling, based on the electrocaloric effect (ECE), is a significant contender for efficient new solid state refrigeration techniques. Some of the highest ECE performances reported are found in compounds close to the morphotropic phase boundary (MPB).

Unfolding grain size effects in barium titanate ferroelectric ceramics.

Grain size effects on the physical properties of polycrystalline ferroelectrics have been extensively studied for decades; however there are still major controversies regarding the dependence of the piezoelectric and ferroelectric properties on the grain size. Dense BaTiO3 ceramics with different grain sizes were fabricated by either conventional sintering or spark plasma sintering using micro- and nano-sized powders. The results show that the grain size effect on the dielectric permittivity is nearly independent of the sintering method and starting powder used.

Phase stability and rapid consolidation of hydroxyapatite-zirconia nano-coprecipitates made using continuous hydrothermal flow synthesis.

A rapid and continuous hydrothermal route for the synthesis of nano-sized hydroxyapatite rods co-precipitated with calcium-doped zirconia nanoparticles using a superheated water flow at 450°C and 24.1 MPa as a crystallizing medium is described. Hydroxyapatite and calcium-doped zirconia phases in the powder mixtures could be clearly identified based on particle size and morphology under transmission electron microscopy.

High-strength nanograined and translucent hydroxyapatite monoliths via continuous hydrothermal synthesis and optimized spark plasma sintering.

The synthesis of high-strength, completely dense nanograined hydroxyapatite (bioceramic) monoliths is a challenge as high temperatures or long sintering times are often required. In this study, nanorods of hydroxyapatite (HA) and calcium-deficient HA (made using a novel continuous hydrothermal flow synthesis method) were consolidated using spark plasma sintering (SPS) up to full theoretical density in ∼5 min at temperatures up to 1000°C. After significant optimization of the SPS heating and loading cycles, fully dense HA discs were obtained which were translucent, suggesting very high densities.