Ecotoxicological characteristics and ecological risk assessment of trace elements in the bottom sediments of the Rożnów reservoir (Poland)

Ecotoxicology - The bottom sediments in catchment areas behind dams play a significant role in water ecosystems. On the other hand, the structure of sediments makes them a natural geosorbent, in...     

Prepubertal Unilateral Gynecomastia: Report of 2 Cases

Prepubertal unilateral gynecomastia is an extremely rare condition. At present, its etiology and management strategy are not well known. Two unrelated prepubertal boys of ages 8 and 9 who presented with complaints of unilateral enlargement of breast tissue are reported. Physical examination, biochemical, hormonal and oncologic work-up findings were normal. Both patients were treated with peripheral liposuction successfully. Histopathological and immunohistochemical examinations showed benign fibroglandular gynecomastia and intensive (3+) estrogen receptor expression in 100% of periductal epithelial cells. Although an extremely rare and generally benign condition, patients with prepubertal unilateral gynecomastia should have a full endocrine and oncologic work-up.     

Safety and efficacy of retrograde intrarenal surgery in geriatric patients by age groups

International Urology and Nephrology - To evaluate the effects of aging on the success rate of retrograde intrarenal surgery (RIRS) and the development of medical and surgical complications by...     

Effect of chitosan nanoparticle,QMix, and EDTA on TotalFill BC sealers’ dentinal tubule penetration: a confocal laser scanning microscopy study

Odontology - The aim of the present study was to compare the effect of chitosan nanoparticle, QMix, and 17% EDTA on the penetrability of a calcium silicate-based sealer into dentinal tubules using...     

The Springer Model for Lifetime Prediction of Wind Turbine Blade Leading Edge Protection Systems: A Review and Sensitivity Study

The wind energy sector is growing rapidly. Wind turbines are increasing in size, leading to higher tip velocities. The leading edges of the blades interact with rain droplets, causing erosion damage over time. In order to mitigate the erosion, coating materials are required to protect the blades. To predict the fatigue lifetime of coated substrates, the Springer model is often used. The current work summarizes the research performed using this model in the wind energy sector and studies the sensitivity of the model to its input parameters. It is shown that the Springer model highly depends on the Poisson ratio, the strength values of the coating and the empirically fitted a2 constant. The assumptions made in the Springer model are not physically representative, and we reasoned that more modern methods are required to accurately predict coating lifetimes. The proposed framework is split into three parts—(1) a contact pressure model, (2) a coating stress model and (3) a fatigue strength model—which overall is sufficient to capture the underlying physics during rain erosion of wind turbine blades. Possible improvements to each of the individual aspects of the framework are proposed.