Single and two-particle energy gaps across the disorder-driven superconductor-insulator transition

The competition between superconductivity and localization raises profound questions in condensed matter physics. In spite of decades of research, the mechanism of the superconductor-insulator transition (SIT) and the nature of the insulator are not understood. We use quantum Monte Carlo simulations that treat, on an equal footing, inhomogeneous amplitude variations and phase fluctuations, a major advance over previous theories. We gain new microscopic insights and make testable predictions for local spectroscopic probes. The energy gap in the density of states survives across the transition, but coherence peaks exist only in the superconductor. A characteristic pseudogap persists above the critical disorder and critical temperature, in contrast to conventional theories. Surprisingly, the insulator has a two-particle gap scale that vanishes at the SIT, despite a robust single-particle gap.Comment: 7 pages, 5 figures (plus supplement with 4 pages, 5 figures

Review Article Oral contraceptives and oral health: an insight

ABSTRAC

Applicability of Preoperative Nuclear Morphometry to Evaluating Risk for Cervical Lymph Node Metastasis in Oral Squamous Cell Carcinoma

Background: We previously reported the utility of preoperative nuclear morphometry for evaluating risk for cervical lymph node metastases in tongue squamous cell carcinoma. The risk for lymph node metastasis in oral squamous cell carcinoma, however, is known to differ depending on the anatomical site of the primary tumor, such as the tongue, gingiva, mouth floor, and buccal mucosa. In this study, we evaluated the applicability of this morphometric technique to evaluating the risk for cervical lymph node metastasis in oral squamous cell carcinoma. Methods: A digital image system was used to measure the mean nuclear area, mean nuclear perimeter, nuclear circular rate, ratio of nuclear length to width (aspect ratio), and nuclear area coefficient of variation (NACV). Relationships between these parameters and nodal status were evaluated by t-test and logistic regression analysis. Results: Eighty-eight cases of squamous cell carcinoma (52 of the tongue, 25 of the gingiva, 4 of the buccal mucosa, and 7 of the mouth floor) were included: 46 with positive node classification and 42 with negative node classification. Nuclear area and perimeter were significantly larger in node-positive cases than in nodenegative cases; however, there were no significant differences in circular rate, aspect ratio, or NACV. We derived two risk models based on the results of multivariate analysis: Model 1, which identified age and mean nuclear area and Model 2, which identified age and mean nuclear perimeter. It should be noted that primary tumor site was not associated the pN-positive status. There were no significant differences in pathological nodal status by aspect ratio, NACV, or primary tumor site. Conclusion: Our method of preoperative nuclear morphometry may contribute valuable information to evaluations of the risk for lymph node metastasis in oral squamous cell carcinoma

Nuclear features in oral squamous cell carcinoma: A computer-assisted microscopic study

Background and Objectives : Oral squamous cell carcinoma (OSCC) is one of the most common tobacco-related cancers affecting the Indian population. Various malignancy-grading systems based on different histopathological features have been proposed for OSCC. Due to inherent subjectivity, inter-observer variation and reproducibility of a grading system remains a problem. Grading systems based on nuclear morphometry have been proposed for laryngeal, renal and pharyngeal carcinomas. In this study, an attempt was made to grade oral OSCC based on computer-assisted microscopic evaluation of nuclear features. Our intention was also to evaluate the use of Feulgen stain for studying nuclear features. Materials and Methods: Sections made from buccal mucosa biopsies of normal mucosa as well as different grades OSCC were stained by Feulgen reaction. The nuclear features were evaluated by computer-assisted microscopic image analysis for nuclear area (NA), nuclear perimeter (NP) and nuclear form factor (NF) and correlated with histologic grading of OSCC. Nuclear shape, membrane outline, chromatin clumps, nucleoli, and abnormal mitoses were also evaluated. Results: NA and NP were observed to be significantly increased in OSCC (P < 0.001) when compared with the control group. These values increased in correlation with increasing grades of OSCC. However, NF was found to more in the control group (P < 0.001). Conclusion: It may be concluded from the results that computer-assisted nuclear morphometry is a reliable tool for grading OSCC. A new grading system based on nuclear features for OSCC has been proposed

Candidiasis - A frequently underdiagnosed entity

Abstract Candidiasis is the most common fungal infection of the oral cavity. It often presents as a white lesion mimicking other oral lesions. It frequently goes undiagnosed in the presence of positive tobacco habit history. The present article reports a case of chronic candidiasis with review of literature. How to cite this article Ashwini R, Nandini DB, Madhushankari GS, Rajeshwari A. Candidiasis - A frequently underdiagnosed entity. CODS J Dent 2014 6;117-121 </jats:sec

White sponge nevus: Report of three cases in a single family

White sponge nevus (WSN) is an interesting hereditary oral mucosal disorder that commonly manifests as bilaterally symmetrical, thickened white, corrugated or velvety, diffuse plaques that predominantly affects the buccal mucosa. The lesions may develop at birth or later in childhood or adolescence. Because it is asymptomatic and benign, WSN requires no treatment. Recognition of this disorder is important due to its potential confusion with other lesions that may be found in the oral cavity. Emphasis should be given to the early and correct diagnosis of this disorder to avoid unnecessary treatment. This report presents three affected members of a single family