Disappearance Of Polarization Research Articles

Specific Smad2/3 Linker Phosphorylation Indicates Esophageal Non-neoplastic and Neoplastic Stem-Like Cells and Neoplastic Development.

There is little known about stem cells in human non-neoplastic and neoplastic esophageal epithelia. We have demonstrated expression of linker threonine-phosphorylated Smad2/3 (pSmad2/3L-Thr), suggesting presence of stem-like cells in mouse esophageal epithelium, and identified presence of pSmad2/3L-Thr-positive cells that might function as cancer stem cells in mouse model of colorectal carcinoma. We explore whether pSmad2/3L-Thr can be used as a biomarker for stem cells of human esophageal epithelia and/or neoplasms. We have used esophageal tissues from inpatients undergoing endoscopic submucosal dissection and performed double immunofluorescent staining of pSmad2/3L-Thr and Ki67, CDK4, p63, Sox2, CK14, p53, ALDH1, CD44 or D2-40 after which the sections were stained with hematoxylin and eosin. pSmad2/3L-Thr-positive cells showed immunohistochemical co-localization with CDK4, p63, CD44 and Sox2 in the basal and parabasal layers of non-neoplastic esophageal epithelia. In esophageal neoplasms, they showed immunohistochemical co-localization with p53, CDK4, ALDH1 and CD44. There was a significant increase in the percentage of pSmad2/3L-Thr-positive cells in the p53-positive neoplastic cell population with development of esophageal neoplasia. pSmad2/3L-Thr-positive cells localized to the lower section of low-grade intraepithelial neoplasia and were observed up to the upper section in carcinoma in situ. In invasive squamous cell carcinoma, they were scattered throughout the tumor with disappearance of polarity and were found in intraepithelial primary lesions and sites of submucosal and vessel invasion. We determined significant expression of pSmad2/3L-Thr in human esophageal non-neoplastic and neoplastic epithelia, indicating that these are epithelial stem-like cells and cancer stem cells, respectively, that correlate with developing esophageal neoplasms.

Successive phase transitions in [C(NH2)3]4Cl2SO4 crystal—dielectric, pyroelectric and optical evidences

Studies of the dielectric and pyroelectric properties of a [C(NH2)3]4Cl2SO4 crystal along the ferroelectric c-axis and the optical observation along the b-axis in the temperature range 330–380K covering the phase transitions region were performed with various heating/cooling rates. At faster heating, a diffused dielectric anomaly in the range of phase transitions was observed. Slow heating (0.01K/min) shows two successive phase transitions: III→II at T2h=354.5K and II→I at T1h=357.5K. Pyroelectric studies showed polar properties of phases III and II. The disappearance of polarization is diffused at the first heating run. The sample kept for 400min in phase II undergoes a direct sharp II→I transition during heating. Optical observations on the heating run at a 0.01K/min rate confirmed successive phase transitions with symmetry changes according to a scheme: orthorhombic (III)→orthorhombic (II)→tetragonal (I). The dielectric, pyroelectric and optical studies revealed a slow III→II transition. On the cooling run, we deal with one transition at T1c equal to 355K between the tetragonal phase (I) and the orthorhombic phase (II).

Appearance and disappearance of polarization and intensity oscillation of secondary electrons emitted from Au/Fe.

Polarization and intensity of secondary electrons emitted from Au(100)/Fe(100) and Au(111)/Fe(110) have been measured for Au thickness from 0 to more than 50 \AA{} with a 0.2-\AA{} thickness resolution. The secondaries emitted from Au(100)/Fe(100) show no periodic oscillations for both intensity and polarization within the sensitivity of our relative intensity and polarization detection of 0.1%. This result shows a significant contrast with that for Au(111)/Fe(110), where the oscillations with amplitudes of a few percent are observed for both the polarization and relative intensity. These results suggest the difference in the nature of interlayer magnetic coupling through Au(100) and Au(111).