Study on the oxidation form of adenine in phosphate buffer solution

The oxidation of adenine in phosphate buffer solution is investigated using square-wave voltammetry and in situ UV spectroelectrochemistry. The geometry of adenine and the derivatives optimized at DFTB3LYP-6-31G (d, p)-PCM level is in agreement with the crystal structure, and the imitated UV spectra of adenine and the product at electrode are consistent with the in situ UV spectra. The relationship between the electrochemical property and the molecular structure is also discussed. The experimental and theoretical results show that the adenine oxidation origins from the neutral adenine.     

Analysis and recognition of touching cell images based on morphological structures

Automated analysis and recognition of cell-nuclear phases using fluorescence microscopy images play an important role for high-content screening. A major task of automated imaging based high-content screening is to segment and reconstruct each cell from the touching cell images. In this paper we present new useful method for recognizing morphological structural models of touching cells, detecting segmentation points, determining the number of segmented cells in touching cell image, finding the related data of segmented cell arcs and reconstructing segmented cells. The conceptual frameworks are based on the morphological structures where a series of structural points and their morphological relationships are established. Experiment results have shown the efficient application of the new method for analysis and recognition of touching cell images of high-content screening.     

Ensembled support vector machines for human papillomavirus risk type prediction from protein secondary structures

Infection by the human papillomavirus (HPV) is regarded as the major risk factor in the development of cervical cancer. Detection of high-risk HPV is important for understanding its oncogenic mechanisms and for developing novel clinical tools for its diagnosis, treatment, and prevention. Several methods are available to predict the risk types for HPV protein sequences. Nevertheless, no tools can achieve a universally good performance for all domains, including HPV and nor do they provide confidence levels for their decisions. Here, we describe ensembled support vector machines (SVMs) to classify HPV risk types, which assign given proteins into high-, possibly high-, or low-risk type based on their confidence level. Our approach uses protein secondary structures to obtain the differential contribution of subsequences for the risk type, and SVM classifiers are combined with a simple but efficient string kernel to handle HPV protein sequences. In the experiments, we compare our approach with previous methods in accuracy and F1-score, and present the predictions for unknown HPV types, which provides promising results.     

Medical Student Dermatology Interest Groups

The Dermatology Interest Group (DIG) at the University of Texas Medical Branch (UTMB) blog (digutmb.blogspot.com) was created in 2004 with the aims of increasing communication and collaboration among students, faculty, residents, and alumni, promoting educational opportunities, and fostering the missions for which DIG was created. This blog is unique, because its frequent activity is directed toward the educational and professional needs of medical students and residents. We assessed the use of this blog by evaluating the number of blog views and audience members with relationship to the number of posts and post content over time via a tracking system. We found that there has been an increase in blog posts, views, and subscribers, as well as in areas of post content including dermatology resources/news/articles, residency applications, and resident-related information. Usefulness of such posts expands beyond UTMB students, which increases blog views and widens viewer audience. An international viewer population also was evaluated. Recorded blog viewing time was 1 minute, 57 seconds, which is more time than needed to read a post, suggesting use of additional blog information. This review of the DIG at the UTMB blog demonstrates how the use of web-based tools, in addition to the inherent benefits of medical student interests groups, are valuable resources for students, residents, and faculty.     

Clinical application of SPHARM-PDM to quantify temporomandibular joint osteoarthritis

The severe bone destruction and resorption that can occur in osteoarthritis of the temporomandibular joint (TMJ) is associated with significant pain and limited joint mobility. However, there is no validated method for the quantification of discrete changes in joint morphology in early diagnosis or assessment of disease progression or treatment effects. To achieve this, the objective of this cross-sectional study was to use simulated bone resorption on cone-beam CT (CBCT) to study condylar morphological variation in subjects with temporomandibular joint (TMJ) osteoarthritis (OA). The first part of this study assessed the hypothesis that the agreement between the simulated defects and the shape analysis measurements made of these defects would be within 0.5 mm (the image's spatial resolution). One hundred seventy-nine discrete bony defects measuring 3 mm and 6 mm were simulated on the surfaces of 3D models derived from CBCT images of asymptomatic patients using ITK-Snap software. SPHARM shape correspondence was used to localize and quantify morphological differences of each resorption model with the original asymptomatic control. The size of each simulated defect was analyzed and the values obtained compared to the true defect size. The statistical analysis revealed very high probabilities that mean shape correspondence measured defects within 0.5 mm of the true defect size. 95% confidence intervals (CI) were (2.67, 2.92) and (5.99, 6.36) and 95% prediction intervals (PI) were (2.22, 3.37) and (5.54, 6.82), respectively for 3 mm and 6 mm simulated defects. The second part of this study applied shape correspondence methods to a longitudinal sample of TMJ OA patients. The mapped longitudinal stages of TMJ OA progression identified morphological variants or subtypes, which may explain the heterogeneity of the clinical presentation. This study validated shape correspondence as a method to precisely and predictably quantify 3D condylar resorption.