Lesión dermatológica en zona de tatuaje / Dermatological lesion in tattoo area

Los tatuajes representan una situación in vivo única en la que una gran cantidad de sales metálicas y tintes orgánicos permanecen en la piel durante toda la vida. Como resultado de un mayor número de tatuajes realizados, la incidencia de complicaciones cutáneas asociadas a los tatuajes ha aumentado también. En los últimos 30 años se ha evidenciado un aumento de reportes de tumores cutáneos en los tatuajes; sin embargo, muchos autores siguen considerándolo un evento fortuito. Los posibles efectos cancerígenos locales de los tatuajes siguen sin estar claros. Se cree que este efecto podría ser multifactorial y que combina traumatismo de la aguja, inflamación local crónica, factores externos como la exposición a los rayos ultravioleta (UV) y un posible efecto pro-cancerígeno de las tintas. Se necesitan estudios epidemiológicos y clínicos a gran escala para demostrar esta asociación. Se presenta un caso de un hombre de 40 años, conocido sano, quien 2 meses después de tatuarse el hombro derecho, desarrolla una lesión con características clínicas de un queratoacantoma y a quien se le realiza el diagnostico histológico de un carcinoma espinocelular bien diferenciado e invasor.

Tattoos represent a unique in vivo situation where many metallic salts and organic dyes remain on the skin for a lifetime. As a result of a greater number of tattoos performed, the incidence of skin complications associated with tattoos has increased. In addition, in the last 30 years, there has been an increment in reports of skin tumors within tattoos; however, many authors continue to consider it is a coincidental event. The possible local carcinogenic effects of tattoos remain unclear. It is believed that this effect could be multifactorial, combining needle trauma, chronic local inflammation, external factors such as an ultraviolet rays (UV) exposure and a possible pro-cancer effect of the inks. Large-scale epidemiological and clinical studies are needed to demonstrate this association. A case of a known healthy 40-year-old male is presented, in whom 2 months after a tattoo was performed on his right shoulder, he developed a lesion with clinical characteristics of a keratoacanthoma in which the histological diagnosis of a well differentiated and invasive squamous cell carcinoma was made.

Previous Repeated Exposure to Food Limitation Enables Rats to Spare Lipid Stores during Prolonged Starvation.

The risk of food limitation and, ultimately, starvation dates back to the dawn of heterotrophy in animals, yet starvation remains a major factor in the regulation of modern animal populations. Researchers studying starvation more than a century ago suggested that animals subjected to sublethal periods of food limitation are somehow more tolerant of subsequent starvation events. This possibility has received little attention over the past decades, yet it is highly relevant to modern science for two reasons. First, animals in natural populations are likely to be exposed to bouts of food limitation once or more before they face prolonged starvation, during which the risk of mortality becomes imminent. Second, our current approach to studying starvation physiology in the laboratory focuses on nourished animals with no previous exposure to nutritional stress. We examined the relationship between previous exposure to food limitation and potentially adaptive physiological responses to starvation in adult rats and found several significant differences. On two occasions, rats were fasted until they lost 20% of their body mass maintained lower body temperatures, and had presumably lower energy requirements when subjected to prolonged starvation than their naive cohort that never experienced food limitation. These rats that were trained in starvation also had lower plasma glucose set -points and reduced their reliance on endogenous lipid oxidation. These findings underscore (1) the need for biologists to revisit the classic hypothesis that animals can become habituated to starvation, using a modern set of research tools; and (2) the need to design controlled experiments of starvation physiology that more closely resemble the dynamic nature of food availability.

High-temperature piezoelectric sensing.

Piezoelectric sensing is of increasing interest for high-temperature applications in aerospace, automotive, power plants and material processing due to its low cost, compact sensor size and simple signal conditioning, in comparison with other high-temperature sensing techniques. This paper presented an overview of high-temperature piezoelectric sensing techniques. Firstly, different types of high-temperature piezoelectric single crystals, electrode materials, and their pros and cons are discussed. Secondly, recent work on high-temperature piezoelectric sensors including accelerometer, surface acoustic wave sensor, ultrasound transducer, acoustic emission sensor, gas sensor, and pressure sensor for temperatures up to 1,250 °C were reviewed. Finally, discussions of existing challenges and future work for high-temperature piezoelectric sensing are presented.