Search

Acid-induced enamel demineralisation affects many individuals either by exposure to acidic diets, acidic gas pollution (dental erosion) or to dental plaque acids (dental caries). This study aimed to develop in situ X-ray and light imaging methods to determine progression of enamel demineralisation and the dynamic relationship between acid pH and mineral density. Hourly digital microradiograph time-lapse sequences showed the depth of enamel demineralisation in 500 µm thick sections progressed with time from the surface towards the dentine following a power-law function, which was 21% faster than the lateral demineralisation progression after exposure for 85 h to lactic acid (10%, pH 2.2). The minimum greyscale remaining (mineral content) within the induced enamel lesion followed an exponential decay, while the accumulated total greyscale loss with time was linear, which showed a constant anisotropic mineral release within the enamel architecture. This 85 h demineralisation method studied by polarised light microscopy time-lapse sequences showed that once the demineralisation front reached the enamel Hunter-Schreger bands, there was preferential demineralisation along those bands. Mineral density loss was linear with increasing pH acidity between pH 5.2 and pH 4.0 (with 0.4 pH increments) when incubated over a 3-week period exposed to 0.5% lactic acid. At pH 4.0, there was complete mineral loss in the centre of the demineralised area after the 3-week period and the linear function intercepted the x-axis at ~ pH 5.5, near the critical pH for hydroxyapatite (HAp). These observations showed how intrinsic enamel structure and pH affected the progression of demineralisation. Hydroxyapatite crystallites (HAp) in human enamel dissolve when exposed to an acidic environment but little is known about how the intrinsic structures in enamel and pH influence the demineralisation kinetics. We have developed a time-lapse in situ microradiography method to quantify microscopic anisotropic mineral loss dynamics in response to an acid-only caries model. Correlation with polarised light microscopy time-lapse sequences showed that larger structures in enamel also influence demineralisation progression as demineralisation occurred preferentially along the Hunter-Schreger bands (decussating prismatic enamel). The pH-controlled enamel mineral release in a linear manner quantifying the relationship between HAp orientation and acid solubility. These findings should direct the development of improved anti-demineralisation/ remineralisation treatments to retain/ restore the natural intrinsic enamel structure. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Supplemental Digital Content is available in the text Objective: To investigate differences in methylation between patients with nondysplastic Barrett esophagus who progress to invasive adenocarcinoma and those who do not. Background: Identifying patients with nondysplastic Barrett esophagus who progress to invasive adenocarcinoma remains a challenge. Previous studies have demonstrated the potential utility of epigenetic markers for identifying this group. Methods: A whole genome methylation interrogation using the Illumina HumanMethylation 450 array of patients with nondysplastic Barrett esophagus who either develop adenocarcinoma or remain static, with validation of findings by bisulfite pyrosequencing. Results: In all, 12 patients with "progressive" versus 12 with "nonprogressive" nondysplastic Barrett esophagus were analyzed via methylation array. Forty-four methylation markers were identified that may be able to discriminate between nondysplastic Barrett esophagus that either progress to adenocarcinoma or remain static. Hypomethylation of the recently identified tumor suppressor OR3A4 (probe cg09890332) validated in a separate cohort of samples (median methylation in progressors 67.8% vs 96.7% in nonprogressors; P = 0.0001, z = 3.85, Wilcoxon rank-sum test) and was associated with the progression to adenocarcinoma. There were no differences in copy number between the 2 groups, but a global trend towards hypomethylation in the progressor group was observed. Conclusion: Hypomethylation of OR3A4 has the ability to risk stratify the patient with nondysplastic Barrett esophagus and may form the basis of a future surveillance program. [ABSTRACT FROM AUTHOR]

Mixed logit models with normally distributed random coefficients are typically estimated under the extreme assumptions that either the random coefficients are completely independent or fully correlated. A factor structured covariance offers a range of alternatives between these two assumptions. However, because these models are more difficult to estimate they are not frequently used to model preference heterogeneity. This paper develops a simple expectation-maximization algorithm for estimating mixed logit models when preferences are generated from a factor structured covariance. The algorithm is easy to implement for both exploratory and confirmatory factor models. The estimator is applied to stated-preference survey data from residential energy customers (Train, 2007). Comparing the fit across five different models, which differed in their assumptions on the covariance of preferences, the results show that all three factor specifications produced a better fit of the data than the fully correlated model measured by BIC and two out of three performed better in terms of AIC. [ABSTRACT FROM AUTHOR]

Abstract: Radiological investigations of the breast are integral to the assessment of symptomatic breast patients and fundamental to the screening programme. Mammography and ultrasound are the standard imaging modalities, supplemented by magnetic resonance imaging in appropriate situations. Possible pathological findings on mammography include masses, architectural distortion, areas of asymmetry between the right and left breast and microcalcification. Ultrasound is the primary method of imaging the breast in younger women. It provides further information about a clinical or mammographic abnormality and can distinguish between solid, cystic or complex lesions. MRI is used in selected cases, to assist with the diagnosis and local staging of primary or recurrent breast cancer. It is also used to assess implant integrity and to screen for malignancy in high-risk women. Image-guided biopsy enables pre-operative diagnosis in most cases of benign and malignant breast conditions. Larger cores of tissue can be obtained with a vacuum assisted biopsy, which may also be used to excise a biopsy-proven benign lesion. As part of the triple assessment, radiological investigations must be correlated with the clinical examination and with any subsequent histology, to ensure-each member of the team is evaluating the same area of the breast. This enables appropriate reassurance to be given when the findings are normal or benign, and accuracy in the diagnosis and staging of patients with breast cancer. [Copyright &y& Elsevier]

Background: Youper is a widely used, commercially available mobile app that uses artificial intelligence therapy for the treatment of anxiety and depression.Objective: Our study examined the acceptability and effectiveness of Youper. Further, we tested the cumulative regulation hypothesis, which posits that cumulative emotion regulation successes with repeated intervention engagement will predict longer-term anxiety and depression symptom reduction.Methods: We examined data from paying Youper users (N=4517) who allowed their data to be used for research. To characterize the acceptability of Youper, we asked users to rate the app on a 5-star scale and measured retention statistics for users' first 4 weeks of subscription. To examine effectiveness, we examined longitudinal measures of anxiety and depression symptoms. To test the cumulative regulation hypothesis, we used the proportion of successful emotion regulation attempts to predict symptom reduction.Results: Youper users rated the app highly (mean 4.36 stars, SD 0.84), and 42.66% (1927/4517) of users were retained by week 4. Symptoms decreased in the first 2 weeks of app use (anxiety: d=0.57; depression: d=0.46). Anxiety improvements were maintained in the subsequent 2 weeks, but depression symptoms increased slightly with a very small effect size (d=0.05). A higher proportion of successful emotion regulation attempts significantly predicted greater anxiety and depression symptom reduction.Conclusions: Youper is a low-cost, completely self-guided treatment that is accessible to users who may not otherwise access mental health care. Our findings demonstrate the acceptability and effectiveness of Youper as a treatment for anxiety and depression symptoms and support continued study of Youper in a randomized clinical trial. [ABSTRACT FROM AUTHOR]

The Indian Government's open policy on satellite television is attracting a plethora of American-based charismatic television ministries in India. This study, albeit based on preliminary findings from a limited study of church and Hindu community leaders, shows that Charismatic pastors are more positive about Charismatic televangelism than non-Charismatic pastors. Both groups, however, have strong reservations on issues like fundraising, dress code and western dancing. The high-caste Hindus revealed during the research that they were resistant to any form of Christian evangelism including televangelism. Besides caste, class, language and gender, televangelism faces cultural barriers in reaching Indians. The prosperity, success and healing doctrines of Charismatic teaching seem to appeal to Hindus from the middle to lower level economic classes. Concerns have been expressed, however, by Christian leaders that these Hindus who are attracted to Charismatic televangelism may be espousing a form of Christianity (loosely termed "popular Christianity") that focuses on personal fulfillment rather than personal holiness and accountability within the life of the Christian community. [ABSTRACT FROM AUTHOR]