Predicting malignancy in thyroid nodules with benign cytology results: The role of Conventional Ultrasound, Shear Wave Elastography and BRAF V600E

BACKGROUND: Ultrasound-guided fine-needle aspiration (US-FNA) is the most accurate method for preoperative diagnosis of thyroid nodules, but how to deal with false negative results. OBJECTIVE: This study aimed to find preoperative diagnosis methods including Conventional Ultrasound (CUS), Shear Wave Elastography (SWE) and BRAF V600E testing to differentiate false negative nodules. METHODS: Forty-nine nodules in 49 patients with benign FNA results and pathological diagnoses were included. CUS and SWE features were evaluated. BRAF V600E analysis was performed after FNA. Diagnostic performances of three methods were analyzed in predicting malignancy in benign FNA results. RESULTS: Twenty-seven of 49 nodules were malignant, and 22 nodules were benign. Hypoechogenicity, taller-than-wider, irregular boundary, microcalcification, SWE max, SWE mean and BRAF V600E mutation were risk factors for malignancy. All 7 malignant nodules with BRAF V600E mutations and 18 of 20 malignant nodules without BRAF V600E mutations have two or more suspicious CUS features. Six of 7 malignant nodules with BRAF V600E mutations and 16 of 20 malignant nodules without BRAF V600E mutations had SWE mean value greater than the cut-off value. CONCLUSIONS: CUS, SWE and BRAF V600E were diagnostic tools for malignancy in FNA benign nodules. Further clinical decisions should be considered for nodules with 2 or more suspicious CUS features and SWE parameters greater than cut-off values whether BRAF V600E is mutational or not.

Calculating Multiple Scattering from a Time-Varying, Undulating Sea Surface Using a Full-Wavefield Multistage Algorithm

The sea surface interface between ocean and air is time varying and can be spatially rough as a result of wind, tides and currents; the shape of this interface changes over time considering the influence of wind, tides, etc. As a result, waves impinging on the sea surface are continuously scattered. In the case of marine seismic, the multiple scattered waves propagate downward into the underwater formation and result in complex seismic responses. To understand the structure of the responses, we propose a multistage algorithm for computing the scattered waves at the sea surface. Specifically, we first extrapolate the upgoing incident waves stepwise using the thin-slab approximation from the scattering theory based on the De Wolf approximation of the Lippmann–Schwinger equation. Then, we implement the air-water boundary condition at the sea surface. Finally, we use the irregular boundary processing technique to compute the time-varying undulating sea-surface scattered waves from different scattering stages. To overcome the angular limitation of the original parabolic approximation, we introduce a multi-directional parabolic approximation based on computational electromagnetics. Numerical tests show that the multistage algorithm presented here can accurately calculate the sea surface scattered waves and should be useful in investigating the structure of marine seismic responses.

Vibration analysis of irregular-shaped plates on simple supports

In this work, we propose a general perturbative approach for modal analysis of irregular-shaped plates of uniform thickness with uniform boundary conditions. Given a plate of irregular boundary, first, a uniform circular plate of identical thickness and area, centred at the centroid, is determined. The irregular boundary is then treated as a perturbation with a suitable smallness parameter, and is expressed as a generalized Fourier series. The frequency parameter, shape function and boundary conditions are then perturbed in terms of the smallness parameter. The homogeneous zeroth-order equation corresponds to the circular plate, which is exactly solvable. We show that the inhomogeneous equations in the higher orders can also be solved exactly using a particular solution structure. We can then construct the exact perturbative solution up to any order. The proposed method is demonstrated through the modal analysis of simply supported super-circular plates. The results are validated using the numerical results obtained from ANSYS ® , which are an excellent match. Interestingly, the supposedly degenerate modes with an even number of nodal diameters of super-circular plates are found to split naturally.

Semiregular and strongly irregular boundary points for p-harmonic functions on unbounded sets in metric spaces

The trichotomy between regular, semiregular, and strongly irregular boundary points for $$p$$ p -harmonic functions is obtained for unbounded open sets in complete metric spaces with a doubling measure supporting a $$p$$ p -Poincaré inequality, $$1<p<\infty $$ 1 < p < ∞ . We show that these are local properties. We also deduce several characterizations of semiregular points and strongly irregular points. In particular, semiregular points are characterized by means of capacity, $$p$$ p -harmonic measures, removability, and semibarriers.

Study on the Shape Optimization of Composite Slope at the End of Irregular Boundary Open-Pit Mine

In order to optimize the shape of the compound slope at the end of the open-pit mine under the condition of non-irregular boundary, the compound slope composed of the stope end and the inner dump in the south of the open-pit mine in Pingshuo is studied. Due to the impact of land acquisition, the space of external dump is seriously insufficient, and with the development and change of mining engineering and the influence of geological structure, the problem of compound form optimization and the release and utilization of internal drain space in the south side is generated. Through field investigation and theoretical analysis and numerical analysis method, on the basis of investigating the ore party production status, to establish a 3 d geological model, select two battery profile typical position, using rigid body limit equilibrium method from the perspective of 2 d, in the full study south help shrink battery limit compound stope side slope and mine safety distance, flat width, and the direction of dump active line and the relationship between the stability design of multiple slope configuration scheme, through the various methods of slope stability, enforceability and comparing some important parameters such as displacement capacity, ultimately determine the technology feasible economic and reasonable boundary zone composite slope space form. Based on the above research results, FLAC3D software was used to study the stress-strain relationship inside the slope, revealing the deformation and failure mechanism and stability of the composite slope in the south bound area. The results show that the landslide mode and stability of the composite slope in the south bound area of pingshuoAndaobao open-pit coal mine are mainly controlled by the safe distance between stope and dump and the weak layer of 11 coal floor. According to the design, the economic and reasonable parameters of the composite slope in the south slope shrinkage boundary area are as follows: the safe distance between the stope end side and the dump site is 50m, the width of the dump flat plate is 60m, and the working line Angle of the dump line with the abandonment height of 255m is 125°, the total discard space was95,934,100 m3.

Dynamic Optimization of Inner Dump in Open-Pit Mining With Irregular Boundary

In order to maximize the profit of open-pit mining with irregular boundary, a dynamic optimization method of internal drainage field is proposed according to the open-pit mining principle. The method according to the site within the space and the relationship between the volume of debris, there will be no rules state within the cross mining row of open pit mining engineering is divided into three periods, namely: site within the space of stage saturated site, inner space, site in excess phase space; By building the stope - inside the mine production model, will work in mine stope and line contact with the three periods established relationship, analyses the various periods stripping engineering problems, and puts forward the corresponding solutions, and for optimal solution. This method is applied to the henan open-pit mine of hollin, a state power investment group. In another mining period, the internal drainage space is fully utilized, which reduces the area of land expropriation by the external drainage and achieves the purpose of reducing cost and increasing efficiency.

MHD flows on irregular boundary over a diverging channel with viscous dissipation effect

Purpose The purpose of this paper is to analyse the force convection laminar boundary layer flow on irregular boundary in diverging channel with the presence of magnetic field effects. Effects of various fluid parameters such as suction/injection, viscous dissipation, magnetic parameter and heat source/sink on velocity and temperature profiles are numerically analyzed. Moreover, numerically investigated on skin-friction and heat transfer coefficients when suction/injection occur. Design/methodology/approach The governing coupled partial differential equations are transformed to dimensionless form using non-similarity transformations. The non-dimensional partial differential equations are linearized by quasi-linearization technique and solved by varga's algorithm with numerical finite difference scheme on a non-uniform mesh. Findings The computation results are presented in terms of temperature, heat transfer and skin friction coefficients; these are useful for determining surface heat requirements. It was found that, in finite difference scheme for non-uniform mesh with quasi-linearization technique method gives smoothness of solution compared to finite difference scheme for uniform mesh, and this evidence is graphically represented in Figure 2. Originality/value The impacts of viscous dissipation (Ec) and magnetic parameter (Ha) on temperature profiles, skin friction and heat transfer are analyzed, which determine the heat generation/absorption to ensure the MHD flow of the laminar boundary layer on irregular boundary over a diverging channel.

Применение модифицированного метода дискретных источников и метода диаграммных уравнений к решению задачи дифракции волн на теле с шероховатой границей

A two-dimensional problem of diffraction on a cylindrical body with a rough boundary is considered. In this work, two aspects of the problem of diffraction on the body with irregular boundary are investigated. First, the problem of diffraction by bodies with random perturbations of the boundary is considered. As an example, diffraction by a rough circular cylinder is considered. The results of calculating the averaged scattering diagram obtained using the modified method of discrete sources are compared with the results obtained using the method of small perturbations. The second goal of this work is to clarify the degree of influence of the small perturbations of the scatterer boundary on the geometry of the set of singularities of the analytical continuation of the diffraction field. As an example, the problem of diffraction by the cylindrical body with a cross-section in the form of a rough multi-leaf, specified in polar and elliptical coordinates, is considered.