Inverse scattering of buried inhomogeneous dielectric material coated on a conductor

[[abstract]]In this paper, the inverse scattering for buried complex material is investigated. An efficient algorithm is proposed to reconstruct the permittivity distribution of buried inhomogeneous dielectric cylinders coated on a conductor has been proposed. The moment method has been used to transform a set of integral equations into matrix form. The algorithm is based on the unrelated illumination method. The theoretical formulation for electromagnetic inverse scattering is presented and numerical results for objects of different permittivity distributions are given and good reconstruction has been obtained, even in the presence of Gaussian noise in measured data.[[conferencetype]]國際[[conferencedate]]20040621~20040626[[conferencelocation]]Kharkov, Ukrain

Inverse scattering of an embedded inhomogeneous dielectric cylinders coated on a conductor

[[abstract]]In this paper, the inverse problem of an embedded inhomogeneous dielectric cylinders coated on a conductor by TM wave illumination is investigated. Inhomogeneous dielectric cylinders coated on a conductor embedded in a slab scatters a group of unrelated incident waves from outside. The scattered field is recorded outside the slab. By proper arrangement of the various unrelated incident field, the difficulties of ill-posedness and nonlinearity are circumvented, and the permittivity distribution can be reconstructed through simple matrix operations. The algorithm is based on the moment method and the unrelated illumination method. Numerical results are given to demonstrate the capability of the inverse algorithm. They also show that the permittivity distribution of the cylinders can be successfully reconstructed even when the permittivity is fairly large. Good reconstructed is obtained even in the presence of additive Gaussian noise in measured data. In addition, the effect of noise on the reconstruction result is also investigated.[[notice]]需補地點及國別[[conferencetype]]國際[[conferencedate]]20060903~2006090

Image reconstruction of buried uniaxial dielectric cylinders

[[abstract]]The inverse scattering of buried inhomogeneous uniaxial dielectric cylinders is investigated. Dielectric cylinders of unknown permittivities are buried in one half space and scatter a group of unrelated waves incident from another half space where the scattered field is recorded. By proper arrangement of the various unrelated incident fields, the difficulties of ill-posedness and nonlinearity. are circumvented, and the permittivity distribution can be reconstructed through simple matrix operations. The algorithm is based on the moment method and the unrelated illumination method. Numerical results are given to demonstrate the capability of the inverse algorithm. Good reconstruction is obtained even in the presence of additive random noise in measured data. In addition, the effect of noise on the reconstruction result is also investigated.[[sponsorship]]台灣大學電機資訊學院; 教育部; 國家科學委員會[[conferencetype]]國際[[conferencedate]]20011203~20011206[[conferencelocation]]Taipei, Taiwa

Inverse scattering of buried complex object by TE wave illumination

[[abstract]]The inverse scattering of buried complex object by transverse electric (TE) wave illumination is investigated. Dielectric cylinders coated on a conductor of unknown permittivities are buried in one half space and scatter a group of unrelated TE waves incident from another half space where the scattered field is recorded. By proper arrangement of the various unrelated incident fields, the difficulties of ill-posedness and nonlinearity are circumvented, and the permittivity distribution can be reconstructed through simple matrix operations. The algorithm is based on the moment method and the unrelated illumination method. Good reconstruction is obtained even in the presence of additive Gaussian random noise in measured data. In addition, the effect of noise on the reconstruction result is also investigated.[[notice]]需補地點及國別[[conferencetype]]國際[[conferencedate]]20050808~2005081

Image reconstruction of dielectric objects by genetic algorithm

[[abstract]]In this paper, an efficient optimization algorithm for solving the inverse problem of a two-dimensional homogeneous dielectric object is investigated. A homogeneous dielectric cylinder of unknown permittivity scatters the incident wave in free space and the scattered fields are recorded. Based on the boundary condition and the incident field, a set of nonlinear surface integral equation is derived. The imaging problem is reformulated into optimization problem and the genetic algorithm is employed to reconstruct the shape and the dielectric constant of the object. Numerical results show that the permittivity of the cylinders can be successfully reconstructed even when the permittivity is fairly large. The effect of random noise on imaging reconstruction is also investigated.[[conferencetype]]國際[[conferencedate]]20030511~20030516[[conferencelocation]]Istanbul, Turke

Image reconstruction of buried dielectric cylinders by TE wave illumination

[[abstract]]The inverse scattering of buried dielectric cylinders by transverse electric (TE) wave illumination is investigated. Dielectric cylinders of unknown permittivities are buried in one half space and scatter a group of unrelated TE waves incident from another half space where the scattered field is recorded. By proper arrangement of the various unrelated incident fields, the difficulties of ill-posedness and nonlinearity are circumvented and the permittivity distribution can be reconstructed through simple matrix operations. Good reconstruction is obtained even in the presence of additive random noise in the measured data.[[conferencetype]]國際[[conferencedate]]20010806~20010810[[conferencelocation]]BRAZIL, Belé

Malignant phyllodes tumors display mesenchymal stem cell features and aldehyde dehydrogenase/disialoganglioside identify their tumor stem cells.

IntroductionAlthough breast phyllodes tumors are rare, there is no effective therapy other than surgery. Little is known about their tumor biology. A malignant phyllodes tumor contains heterologous stromal elements, and can transform into rhabdomyosarcoma, liposarcoma and osteosarcoma. These versatile properties prompted us to explore their possible relationship to mesenchymal stem cells (MSCs) and to search for the presence of cancer stem cells (CSCs) in phyllodes tumors.MethodsParaffin sections of malignant phyllodes tumors were examined for various markers by immunohistochemical staining. Xenografts of human primary phyllodes tumors were established by injecting freshly isolated tumor cells into the mammary fat pad of non-obese diabetic-severe combined immunodeficient (NOD-SCID) mice. To search for CSCs, xenografted tumor cells were sorted into various subpopulations by flow cytometry and examined for their in vitro mammosphere forming capacity, in vivo tumorigenicity in NOD-SCID mice and their ability to undergo differentiation.ResultsImmunohistochemical analysis revealed the expression of the following 10 markers: CD44, CD29, CD106, CD166, CD105, CD90, disialoganglioside (GD2), CD117, Aldehyde dehydrogenase 1 (ALDH), and Oct-4, and 7 clinically relevant markers (CD10, CD34, p53, p63, Ki-67, Bcl-2, vimentin, and Globo H) in all 51 malignant phyllodes tumors examined, albeit to different extents. Four xenografts were successfully established from human primary phyllodes tumors. In vitro, ALDH+ cells sorted from xenografts displayed approximately 10-fold greater mammosphere-forming capacity than ALDH- cells. GD2+ cells showed a 3.9-fold greater capacity than GD2- cells. ALDH+/GD2+cells displayed 12.8-fold greater mammosphere forming ability than ALDH-/GD2- cells. In vivo, the tumor-initiating frequency of ALDH+/GD2+ cells were up to 33-fold higher than that of ALDH+ cells, with as few as 50 ALDH+/GD2+ cells being sufficient for engraftment. Moreover, we provided the first evidence for the induction of ALDH+/GD2+ cells to differentiate into neural cells of various lineages, along with the observation of neural differentiation in clinical specimens and xenografts of malignant phyllodes tumors. ALDH+ or ALDH+/GD2+ cells could also be induced to differentiate into adipocytes, osteocytes or chondrocytes.ConclusionsOur findings revealed that malignant phyllodes tumors possessed many characteristics of MSC, and their CSCs were enriched in ALDH+ and ALDH+/GD2+ subpopulations