SHG microscopic observations of polar state in Li-doped KTaO3 under electric field

Incipient ferroelectric KTaO3 with off-center Li impurity of the critical concentration of 2.8 mol% was investigated in order to clarify the dipole glass state under electric field. Using optical second-harmonic generation (SHG) microscope, we observed a marked history dependence of SHG intensity through zero-field cooling (ZFC), zero-field heating (ZFH), field heating after ZFC (FH/ZFC) and FH after field cooling (FH/FC). These show different paths with respect to temperature: In the ZFC/ZFH process, weak SHG was observed at low temperature, while in the FH/ZFC process, relatively high SHG appears in a limited temperature range below TF depending on the field strength, and in the FC and FH/FC processes, the SHG exhibits ferroelectric-like temperature dependence: it appears at the freezing temperature of 50K, increases with decreasing temperature and has a tendency of saturation. These experimental results strongly suggest that dipole glass state or polar nano-clusters which gradually freezes with decreasing temperature is transformed into semi-macroscopic polar state under the electric field. However at sufficiently low temperature, the freezing is so strong that the electric field cannot enlarge the polar clusters. These experimental results show that the polar nano-cluster model similar to relaxors would be more relevant in KTaO3 doped with the critical concentration of Li. Further experiments on the anisotropy of SHG determine that the average symmetry of the field-induced polar phase is tetragonal 4mm or 4, which is also confirmed by the X-ray diffraction measurement.Comment: 26 pages, 8 figures, 1 tabl

Mucocele-like lesions of the breast: a long-term follow-up study

<p>Abstract</p> <p>Background</p> <p>Mucocele-like lesions (MLL) of the breast were originally described as benign lesions composed of multiple cysts lined by uniform flat to cuboidal epithelium with extravasated mucin, but subsequent reports described the coexistence of columnar cell lesions (CCL), atypical ductal hyperplasia (ADH) and ductal carcinoma in situ (DCIS). Several reports have investigated whether core biopsy can diagnose MLL reliably; however, there is only one report with a long-term follow-up after excision of MLL. We report here 15 surgically excised MLL with a long-term follow-up.</p> <p>Findings</p> <p>Fifteen lesions diagnosed as MLL from 13 patients who had undergone excisional biopsy between January 2001 and December 2006 were retrieved and followed-up for 24-99 months (median 63.8). Two lesions were accompanied with CCL, 5 with ADH and 3 with low grade DCIS. Four lesions (2 ADH, 2 DCIS) were additionally resected and their histology revealed 2 ADH, one DCIS and one MLL with CCL. Of 4 lesions (3 ADH, one DCIS) without additional resection, one lesion (ADH) relapsed accompanied with DCIS at 37 months after excision.</p> <p>Conclusions</p> <p>MLL were frequently accompanied with CCL, ADH or low grade DCIS. Complete resection may be recommended in case of MLL with ADH or DCIS because of intralesional heterogeneity and the probabilities of relapse.</p

Review on understanding of death and life in childhood : Development and factors

This paper reviewed the studies on understanding of death and life in childhood, on the basis of the arrangement, new viewpoints for the course of researches in the future were given. First, the knowledge of development of understanding of death and life was arranged every subject such as the concept of death, concepts of animated beings and living beings, emotions and images about death and life , and attitudes toward death and life. Second, the knowledge of factors in relation to understanding of death and life was put in order every subject such as gender difference, self-esteem and development of ego, personality, individual experience, and cultural adn regionus backgrounds. Finally, the following viewpoints for the furture researches were proposed : (1) to understand death and life as the construction of cognitional, emotional, behavioral sides and of ranging over consciousness to unconsciousness, (2) to turn our attention to \u22inochi\u22 which means life in Japanese, (3) to examine the relations between understandeing of death and life and various factors inclusively (especially for self-esteem, empathy, and agression)