3,658 research outputs found
Segmentation of ultrasound images of thyroid nodule for assisting fine needle aspiration cytology
The incidence of thyroid nodule is very high and generally increases with the
age. Thyroid nodule may presage the emergence of thyroid cancer. The thyroid
nodule can be completely cured if detected early. Fine needle aspiration
cytology is a recognized early diagnosis method of thyroid nodule. There are
still some limitations in the fine needle aspiration cytology, and the
ultrasound diagnosis of thyroid nodule has become the first choice for
auxiliary examination of thyroid nodular disease. If we could combine medical
imaging technology and fine needle aspiration cytology, the diagnostic rate of
thyroid nodule would be improved significantly. The properties of ultrasound
will degrade the image quality, which makes it difficult to recognize the edges
for physicians. Image segmentation technique based on graph theory has become a
research hotspot at present. Normalized cut (Ncut) is a representative one,
which is suitable for segmentation of feature parts of medical image. However,
how to solve the normalized cut has become a problem, which needs large memory
capacity and heavy calculation of weight matrix. It always generates over
segmentation or less segmentation which leads to inaccurate in the
segmentation. The speckle noise in B ultrasound image of thyroid tumor makes
the quality of the image deteriorate. In the light of this characteristic, we
combine the anisotropic diffusion model with the normalized cut in this paper.
After the enhancement of anisotropic diffusion model, it removes the noise in
the B ultrasound image while preserves the important edges and local details.
This reduces the amount of computation in constructing the weight matrix of the
improved normalized cut and improves the accuracy of the final segmentation
results. The feasibility of the method is proved by the experimental results.Comment: 15pages,13figure
Nuclear superfluidity for antimagnetic rotation in Cd and Cd
The effect of nuclear superfluidity on antimagnetic rotation bands in
Cd and Cd are investigated by the cranked shell model with the
pairing correlations and the blocking effects treated by a particle-number
conserving method. The experimental moments of inertia and the reduced
transition values are excellently reproduced. The nuclear superfluidity is
essential to reproduce the experimental moments of inertia. The two-shears-like
mechanism for the antimagnetic rotation is investigated by examining the shears
angle, i.e., the closing of the two proton hole angular momenta, and its
sensitive dependence on the nuclear superfluidity is revealed.Comment: 14 pages, 4 figure
Automated Segmentation of Pulmonary Lobes using Coordination-Guided Deep Neural Networks
The identification of pulmonary lobes is of great importance in disease
diagnosis and treatment. A few lung diseases have regional disorders at lobar
level. Thus, an accurate segmentation of pulmonary lobes is necessary. In this
work, we propose an automated segmentation of pulmonary lobes using
coordination-guided deep neural networks from chest CT images. We first employ
an automated lung segmentation to extract the lung area from CT image, then
exploit volumetric convolutional neural network (V-net) for segmenting the
pulmonary lobes. To reduce the misclassification of different lobes, we
therefore adopt coordination-guided convolutional layers (CoordConvs) that
generate additional feature maps of the positional information of pulmonary
lobes. The proposed model is trained and evaluated on a few publicly available
datasets and has achieved the state-of-the-art accuracy with a mean Dice
coefficient index of 0.947 0.044.Comment: ISBI 2019 (Oral
4-(Diphenylphosphanyl)benzoic acid
In the title compound, C19H15O2P, the dihedral angles between the benzoic acid ring and the phenyl rings are 75.64 (7) and 80.88 (7)°; the dihedral angle between the phenyl rings is 81.35 (7)°. In the crystal, inversion dimers linked by pairs of O—H⋯O hydrogen bonds generate R
2
2(8) loops between the head-to-head carboxylic acid groups
Diphenyl chlorothiophosphonate
The complete molecule of the title compound, C12H10ClO2PS, is generated by crystallographic mirror symmetry, with the P, S and Cl atoms lying on the mirror plane. The resulting PO2SCl tetrahedron is significantly distorted [O—P—O = 96.79 (9)°]. The crystal packing exhibits no directional interactions
Rotational properties of the superheavy nucleus 256Rf and its neighboring even-even nuclei in particle-number conserving cranked shell model
The ground state band was recently observed in the superheavy nucleus 256Rf.
We study the rotational properties of 256Rf and its neighboring even-even
nuclei by using a cranked shell model (CSM) with the pairing correlations
treated by a particle-number conserving (PNC) method in which the blocking
effects are taken into account exactly. The kinematic and dynamic moments of
inertia of the ground state bands in these nuclei are well reproduced by the
theory. The spin of the lowest observed state in 256Rf is determined by
comparing the experimental kinematic moments of inertia with the PNC-CSM
calculations and agrees with previous spin assignment. The effects of the high
order deformation varepsilon6 on the angular momentum alignments and dynamic
moments of inertia in these nuclei are discussed.Comment: 7 pages, 6 figures; References and discussion about the cranking
Nilsson model added, Fig. 3 modified and Figs. 5 and 6 added; Phys. Rev. C,
in pres
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