RESUMO
Emerging intraoperative tumor margin assessment techniques require the development of more complex and reliable organ phantoms to assess the performance of the technique before its translation into the clinic. In this work, electrically conductive tissue-mimicking materials (TMMs) based on fat, water and agar/gelatin were produced with tunable optical properties. The composition of the phantoms allowed for the assessment of tumor margins using diffuse reflectance spectroscopy, as the fat/water ratio served as a discriminating factor between the healthy and malignant tissue. Moreover, the possibility of using polyvinyl alcohol (PVA) or transglutaminase in combination with fat, water and gelatin for developing TMMs was studied. The diffuse spectral response of the developed phantom materials had a good match with the spectral response of porcine muscle and adipose tissue, as well as in vitro human breast tissue. Using the developed recipe, anatomically relevant heterogeneous breast phantoms representing the optical properties of different layers of the human breast were fabricated using 3D-printed molds. These TMMs can be used for further development of phantoms applicable for simulating the realistic breast conserving surgery workflow in order to evaluate the intraoperative optical-based tumor margin assessment techniques during electrosurgery.
RESUMO
Using an intraoperative margin assessment technique during breast-conserving surgery (BCS) helps surgeons to decrease the risk of positive margin occurrence. Diffuse reflectance spectroscopy (DRS) has the potential to discriminate healthy breast tissue from cancerous tissue. We investigated the performance of an electrosurgical knife integrated with a DRS on porcine muscle and adipose tissue. Characterization of the formed debris on the optical fibers after electrosurgery revealed that the contamination is mostly burned tissue. Even with contaminated optical fibers, both tissues could still be discriminated with DRS based on fat/water ratio. Therefore, an electrosurgical knife integrated with DRS may be a promising technology to provide the surgeon with real-time guidance during BCS.
RESUMO
The age at menarche is an indicator of racial, geographical and nutritional patterns of different societies. This cross-sectional study conducted on 1223 girls aged 14-20 in the Markazi (Central) Province, Iran in 2010. In this research, the age at menarche, as the main variable, was determined for each city and compared between different cities. The statistical analyses included c2 test for determining statistically significant differences, variance analysis for determining the difference between groups, and Pearson correlation coefficient for determining the relationship between variables. The average age of first menstruation was 13.21+/-1.33 years in the Markazi Province, with no significant difference among the cities of the province. This age is inversely related to body mass index (BMI), nutritional status and weight. The pattern of distribution of BMI is similar for all the cities in the province. Although, the average age at menarche in the Markazi (central) Province, a cold area, is higher compared to warmer regions in Iran, it may be more influenced by race than by the climate. Considering the lower age at menarche in Markazi Province compared to previous similar studies, it may be stated that social well-being and nutritional standards have improved in the province.
La edad de la menarquia es un indicador de patrones raciales, geográficos y nutricionales de distintas sociedades. Este estudio transversal fue realizado el 2010 en 1223 niñas entre 14 y 20 años en la Provincia Markazi (Central), Irán. En esta investigación, la edad de la menarquia, como la variable principal, se determinaron para cada ciudad y en comparación entre las diferentes ciudades. Los análisis estadísticos incluyeron la prueba c2 para determinar diferencias estadísticamente significativas, el análisis de varianza para determinar la diferencia entre los grupos, y el coeficiente de correlación de Pearson para determinar la relación entre las variables. El promedio de edad de la primera menstruación fue 13,21+/-1,33 años en la provincia de Markazi, sin diferencias significativas entre las ciudades de la provincia. Esta edad es inversamente proporcional al índice de masa corporal (IMC), el estado nutricional y el peso. El patrón de distribución del IMC es similar para todas las ciudades de la provincia. Aunque la edad media de la menarquia en la Provincia Markazi (central), una zona de clima frío, es mayor en comparación con las regiones más cálidas en Irán, puede estar más influenciadas por la raza que por el clima. Teniendo en cuenta la baja edad de menarquia en la Provincia Markazi en comparación con estudios similares anteriores, se puede afirmar que el bienestar social y los niveles de nutrición han mejorado en la provincia.
