Search

Abstract Objectives Esophagogastroduodenoscopy (EGD) is a widely used modality for investigating the upper gastrointestinal (GI) tract, similar to endoscopic ultrasonography (EUS) for the pancreaticobiliary system. A recent and novel forward‐viewing radial EUS has potential as an EGD. However, this potential has not yet been evaluated and reported in the literature. We compared the depictability of the upper GI tract on EUS using a standard EGD. Methods This was a prospective study in a single session in an identical patient and it was conducted at a single center. Results Sixty‐nine participants were enrolled in this study. A forward‐viewing radial EUS revealed equivalent visualizing performance compared with the standard EGD, except for the retroflex view of the three angular areas. Depiction scores of the anterior wall, lesser curvature, and posterior wall of the angulus in the retroflex view in the forward‐viewing radial EUS were 1.94 (95% confidence interval [CI], 1.36–2.52), 2.03 (95% CI, 1.48–2.58), and 1.93 (95% CI, 1.35–2.50), respectively. These scores were significantly lower compared with those of standard EGD scores of 2.97 (95% CI, 2.86–3.08), 2.97 (95% CI, 2.86–3.78), and 2.96 (95% CI, 2.83–3.09], respectively; p

Vascular diseases such as atherosclerosis and aneurysms are associated with diet. Perivascular adipose tissue (PVAT) was reportedly involved in the regulation of vascular functions. It is suggested that imbalanced diets can cause PVAT inflammation and dysfunction as well as impaired vascular function. However, the association between diets and PVAT are not clearly understood. Here, we showed that a high-fat and a high-sucrose diet affected PVAT at different sites. A high-fat diet induced increased number of large-sized lipid droplets and increased CD (Cluster of differentiation) 68+ macrophage- and monocyte chemotactic protein (MCP)-1-positive areas in the abdominal aortic PVAT (aPVAT). In addition, a high-fat diet caused decreased collagen fibre-positive area and increased CD68+ macrophage- and MCP-1-positive areas in the abdominal aorta. In contrast, a high-sucrose diet induced increased number of large-sized lipid droplets, increased CD68+ macrophage- and MCP-1-positive areas, and decreased UCP-1 positive area in the thoracic aortic PVAT (tPVAT). A high-sucrose diet caused decreased collagen fibre-positive area and increased CD68+ macrophage- and MCP-1-positive areas in the thoracic aorta. These results could be attributed to the different adipocyte populations in the tPVAT and aPVAT. Our results provide pathological evidence to improve our understanding of the relationship between diet and vascular diseases.

Research interest has been growing in recent years in supersonic transport, particularly supersonic propulsion systems. A key component of a commonly studied propulsion system, ramjets, is the air intake. For supersonic propulsion systems a major factor in the overall efficiency is the intake pressure recovery. This refers to the ratio of the average total pressure after the intake to that of the freestream. One phenomenon that can have a large effect on this performance index is flow separation at the inlet. The aim of this work is to examine how pulsed laser energy deposition can be used to improve pressure recovery performance by reducing flow separation at the inlet. This research examines the effects of pulsed laser energy deposition upstream of an intake with an axisymmetric centrebody in a Mach 1.92 indraft wind tunnel. Laser frequency was varied between 1 and 60 kHz with an energy per pulse of 5.6 mJ. Schlieren photography was used to examine the fundamental fluid dynamics while total and static pressure downstream of the intake diffuser were measured to examine the resulting effect on the performance. Schlieren imaging shows that the interaction between the laser generated thermal bubble and the leading edge shock produced by the centrebody results in a significant reduction in separation along the intake cone. Analysis of the schlieren results and the pressure results in tandem illustrate that the average separation location along the length of the centrebody directly correlates to the pressure recovery observed in the intake. At the optimal laser frequency, found for this Mach number to be 10 kHz, the pressure recovery is found to increase by up to 4.7%. When the laser power added to the system is considered, this results in an overall increase in propulsive power of 2.47%. Keywords: Laser energy deposition, Supersonic, Flow dynamics, Intakes, Flow separation

We evaluate the energy conversion efficiency of an electrical exploding foil accelerator that accelerates a thin dielectric foil (called the flyer) to more than 1 km/s, which is propelled by electrically exploded bridge material. The effective flyer mass ejected from the accelerator is estimated by impulse measurements obtained using a gravity pendulum as well as by time-resolving flyer velocity measurements obtained using a photonic Doppler velocimetry system. For two different bridge sizes (0.2 and 0.4 mm), the flyer velocity and impulse increase with the input energy at the bridge section. The maximum flyer velocity and impulse, that is, 4.0 km/s and 67 µN s, respectively, are obtained by supplying 0.33 J of input energy. Upon increasing the input energy, the effective flyer mass also increases and exceeds the designed-bridge mass for both bridge sizes. The energy conversion efficiency from input electrical energy to flyer kinetic energy is calculated based on the effective flyer mass, velocity, and input energy. Both bridge sizes show comparable efficiencies: 27% and 30% for 0.2 and 0.4 mm bridges, respectively. The efficiency increases with increasing specific input energy at least up to 15 MJ/kg for the 0.4 mm bridge, whereas the efficiency of the 0.2 mm bridge above 30 MJ/kg decreases. This is owing to the excessively high input energy density in the 0.2 mm bridge, which causes the effective flyer mass to increase by including surrounding materials. These results indicate that the specific input energy should be optimized for obtaining maximum efficiency.

This paper discusses that the unsteady aerodynamic forces caused by vehicle motion in road input have a large influence on the vehicle behaviors. In the present coupling analysis, unsteady aerodynamic forces were obtained by using the response functions for vehicle motion derived in our previous study. By attaching a protrusion on the roof which only measures about 3% of the vehicle height, pitch and heave motions are affected significantly by the change of unsteady aerodynamic effects. Due to the coupling of the unsteady aerodynamic forces and vehicle suspension responses, the vehicle behavior depends on the road input frequency. The pitch motion is enhanced in low-frequency road input (1.6 Hz). Meanwhile, the heave motion is suppressed over 1.2 Hz. Such vehicle behaviors were verified in actual running tests, and were consistent to the subjective evaluation of the drivers feeling. Comparing the unsteady aerodynamic coefficients to the equivalent vehicle specification factors, the aerodynamic inertia caused by pitch motion contributes to 39% of the rear vehicle mass inertia effect in pitch motion. This aerodynamic effect is important in designing suspension specifications of vehicles. These results show that the vehicle stability can be affected even by small detail in vehicle shape due to the unsteady aerodynamic forces.