Thyroid tumors include those that originate from follicular cells and those that arise from parafollicular cells (C cells). Differentiated thyroid cancer, which originates from follicular cells, includes papillary car...Thyroid tumors include those that originate from follicular cells and those that arise from parafollicular cells (C cells). Differentiated thyroid cancer, which originates from follicular cells, includes papillary carcinoma, follicular carcinoma, oncocytic cell carcinoma (Hürthle), poorly differentiated carcinoma, and anaplastic carcinoma. The incidence of thyroid cancer has been increasing significantly, with an estimated incidence in the United States of America of 53,990 cases by the year 2018. This neoplasm is listed as the most common endocrine tumor and represents approximately 3% of all malignant tumors in humans, with 75% of cases occurring in women, and two-thirds of cases occurring in people under 55 years. The increase in the prevalence/incidence of low-risk thyroid cancer over the last 10 to 20 years has required a re-appraisal of the standard one-size-fits-all approach to differentiated thyroid cancer. This adaptation to a more individualized management of the patient with thyroid cancer has led to a much more risk-adapted approach to the diagnosis, initial therapy, adjuvant therapy, and follow-up of patients with differentiated thyroid cancer. This paper with review the current understanding of the clinical presentation, diagnostic workup, and management of thyroid cancer centered on evidence-based and personalized medicine.展开更多
This work investigated the absorbed dose to water rate under reference conditions in a Cyberknife VSI system using radiochromic films EBT3 and MD-V3 and three ionization chambers: an Exradin A12 and two FC65P Welh&...This work investigated the absorbed dose to water rate under reference conditions in a Cyberknife VSI system using radiochromic films EBT3 and MD-V3 and three ionization chambers: an Exradin A12 and two FC65P Welhöfer Scanditronix with different serial numbers. The correction factor,, was studied using a Varian iX linac and the Cyberknife system. The measurements in the Varian iX were performed in a 10 × 10 cm2 field, 10 cm depth in liquid water at 90 cm and 70 cm SSD and in a 5.4 × 5.4 cm2 field, 10 cm depth at 70 cm SSD to simulate the Cyberknife conditions. In the Cyberknife system, measurements were performed using ionization chambers and both film types at 70 cm SSD and 10 cm depth in its 6 cm diameter reference field. The results indicate that ?is independent of the dosimeters and the evaluation methods. Maximum differences of 0.22% - 0.55% (combined uncertainties of 1.22% - 1.98%, k = 1) are obtained on ?using Varian iX, whereas discrepancies of 2.08% - 2.09% (combined uncertainties of 1.87% - 2.13%, k = 1) are observed using the Cyberknife system. Given the agreement between detectors and the combined standard uncertainties, the data from Varian iX could be considered the most accurate and consequently a weighted average factor of 0.902 ± 0.006 could be used for the Cyberknife VSI system reference field. Within measurement uncertainties, the absorbed dose rate measured in the Cyberknife VSI system reference field was found to be independent of the dosimeters used. These results suggest that the absorbed dose measured at a point within a given field size should be the same, regardless the dosimeter used, if their dosimetric characteristics are well known. This highlighted the importance of performing dosimetry by controlling all parameters that could affect the dosimeter response. One can conclude that radiochromic film dosimetry can be considered as an appropriate alternative for measuring absorbed dose to water rate.展开更多
Emerging contaminants constitute a set of substances that are released into the environment for which regulations are currently not established for their environmental monitoring, being antimony one of them. A new met...Emerging contaminants constitute a set of substances that are released into the environment for which regulations are currently not established for their environmental monitoring, being antimony one of them. A new methodology for Sb(III) traces monitoring by solid surface fluorescence is proposed. The metal was complexed with alizarine (Az) as fluorosphore reagent in alcaline medium in presence of the bile salt sodium cholate. To isolate the analyte of matrix constituents, a preconcentration/separation strategy on filter paper was introduced prior to determination step. The solid surface fluorescence was measured λem = 450 nm and λexc = 363 nm using a solid sampler holder. Under optimal conditions, the limits of detection and quantification of proposed methodology were 0.08 and 0.24 μg·L-1, respectively, showing a linear range from 0.24 to 304.4 μg·L-1 with good sensitivity and adequate selectivity. It was applied to the Sb(III) traces determination present in drinking water and beverages samples packaged in polyethylene terephthalate (PET) bottles widely consumed in Argentina. The combination of a preconcentration step on common filter paper and the inherent sensitivity of photoluminescent methods have permitted to achieve sensitivity similar to atomic spectroscopies using a lower price instrument typical in control laboratories. Precision and accuracy were tested with excellent agreement. Results were truenessed by ETAAS with satisfactory concordance.展开更多
Using the transfer matrix method we calculate the frequency dependence of the transmission of longitudinal elastic waves for a layered structure where the specific acoustic impedance of the layers with odd numbering f...Using the transfer matrix method we calculate the frequency dependence of the transmission of longitudinal elastic waves for a layered structure where the specific acoustic impedance of the layers with odd numbering follows a Gaussian distribution, while the inserted even layers have the same impedance as the propagation medium. The structure presents intervals of low-pass, band-stop, and band-pass. The characteristics of the bands depend on the number of layers, on the contrast between the maximum and minimum impedances of the structure, and on the ratio of the width of the inserted layers to the width of the layers with a Gaussian distribution of impedances.展开更多
A case of gouty tophus in the elbow of a 62-year-old male is presented. Fine-needle aspiration (FNA) revealed the presence of acicular crystals, birefringent when viewed under polarized light as is typical for monosod...A case of gouty tophus in the elbow of a 62-year-old male is presented. Fine-needle aspiration (FNA) revealed the presence of acicular crystals, birefringent when viewed under polarized light as is typical for monosodium urate crystals. Histological study of the removed lesion confirmed a typical gouty tophus. We briefly comment the main characteristics of this entity.展开更多
We present morphological findings observed from the study of a myxopapillary ependymoma located in the III ventricle. This tumor, which is a rare occurrence at this level, was observed in a 73-year-old woman with no r...We present morphological findings observed from the study of a myxopapillary ependymoma located in the III ventricle. This tumor, which is a rare occurrence at this level, was observed in a 73-year-old woman with no relevant medical history who presented with obstructive hydrocephalus due to compression and blockage of the foramen of Monro. The good delineation of the lesion allowed its surgical excision, and histological examination of the material obtained after excisional biopsy revealed a glial neoplasm with a low degree of cytological malignancy that was strongly positive for glial fibrillary acidic protein (GFAP) as well as a myxopapillary architecture analogous to that observed in ependymomas of the filum terminale. Subsequent radiological examination allowed us to rule out a metastatic nature of the tumor, confirming its primary origin. We briefly discuss the case and review the main characteristics of this neoplasia, which is quite rare at the site identified in our patient.展开更多
文摘Thyroid tumors include those that originate from follicular cells and those that arise from parafollicular cells (C cells). Differentiated thyroid cancer, which originates from follicular cells, includes papillary carcinoma, follicular carcinoma, oncocytic cell carcinoma (Hürthle), poorly differentiated carcinoma, and anaplastic carcinoma. The incidence of thyroid cancer has been increasing significantly, with an estimated incidence in the United States of America of 53,990 cases by the year 2018. This neoplasm is listed as the most common endocrine tumor and represents approximately 3% of all malignant tumors in humans, with 75% of cases occurring in women, and two-thirds of cases occurring in people under 55 years. The increase in the prevalence/incidence of low-risk thyroid cancer over the last 10 to 20 years has required a re-appraisal of the standard one-size-fits-all approach to differentiated thyroid cancer. This adaptation to a more individualized management of the patient with thyroid cancer has led to a much more risk-adapted approach to the diagnosis, initial therapy, adjuvant therapy, and follow-up of patients with differentiated thyroid cancer. This paper with review the current understanding of the clinical presentation, diagnostic workup, and management of thyroid cancer centered on evidence-based and personalized medicine.
文摘This work investigated the absorbed dose to water rate under reference conditions in a Cyberknife VSI system using radiochromic films EBT3 and MD-V3 and three ionization chambers: an Exradin A12 and two FC65P Welhöfer Scanditronix with different serial numbers. The correction factor,, was studied using a Varian iX linac and the Cyberknife system. The measurements in the Varian iX were performed in a 10 × 10 cm2 field, 10 cm depth in liquid water at 90 cm and 70 cm SSD and in a 5.4 × 5.4 cm2 field, 10 cm depth at 70 cm SSD to simulate the Cyberknife conditions. In the Cyberknife system, measurements were performed using ionization chambers and both film types at 70 cm SSD and 10 cm depth in its 6 cm diameter reference field. The results indicate that ?is independent of the dosimeters and the evaluation methods. Maximum differences of 0.22% - 0.55% (combined uncertainties of 1.22% - 1.98%, k = 1) are obtained on ?using Varian iX, whereas discrepancies of 2.08% - 2.09% (combined uncertainties of 1.87% - 2.13%, k = 1) are observed using the Cyberknife system. Given the agreement between detectors and the combined standard uncertainties, the data from Varian iX could be considered the most accurate and consequently a weighted average factor of 0.902 ± 0.006 could be used for the Cyberknife VSI system reference field. Within measurement uncertainties, the absorbed dose rate measured in the Cyberknife VSI system reference field was found to be independent of the dosimeters used. These results suggest that the absorbed dose measured at a point within a given field size should be the same, regardless the dosimeter used, if their dosimetric characteristics are well known. This highlighted the importance of performing dosimetry by controlling all parameters that could affect the dosimeter response. One can conclude that radiochromic film dosimetry can be considered as an appropriate alternative for measuring absorbed dose to water rate.
文摘Emerging contaminants constitute a set of substances that are released into the environment for which regulations are currently not established for their environmental monitoring, being antimony one of them. A new methodology for Sb(III) traces monitoring by solid surface fluorescence is proposed. The metal was complexed with alizarine (Az) as fluorosphore reagent in alcaline medium in presence of the bile salt sodium cholate. To isolate the analyte of matrix constituents, a preconcentration/separation strategy on filter paper was introduced prior to determination step. The solid surface fluorescence was measured λem = 450 nm and λexc = 363 nm using a solid sampler holder. Under optimal conditions, the limits of detection and quantification of proposed methodology were 0.08 and 0.24 μg·L-1, respectively, showing a linear range from 0.24 to 304.4 μg·L-1 with good sensitivity and adequate selectivity. It was applied to the Sb(III) traces determination present in drinking water and beverages samples packaged in polyethylene terephthalate (PET) bottles widely consumed in Argentina. The combination of a preconcentration step on common filter paper and the inherent sensitivity of photoluminescent methods have permitted to achieve sensitivity similar to atomic spectroscopies using a lower price instrument typical in control laboratories. Precision and accuracy were tested with excellent agreement. Results were truenessed by ETAAS with satisfactory concordance.
文摘Using the transfer matrix method we calculate the frequency dependence of the transmission of longitudinal elastic waves for a layered structure where the specific acoustic impedance of the layers with odd numbering follows a Gaussian distribution, while the inserted even layers have the same impedance as the propagation medium. The structure presents intervals of low-pass, band-stop, and band-pass. The characteristics of the bands depend on the number of layers, on the contrast between the maximum and minimum impedances of the structure, and on the ratio of the width of the inserted layers to the width of the layers with a Gaussian distribution of impedances.
文摘A case of gouty tophus in the elbow of a 62-year-old male is presented. Fine-needle aspiration (FNA) revealed the presence of acicular crystals, birefringent when viewed under polarized light as is typical for monosodium urate crystals. Histological study of the removed lesion confirmed a typical gouty tophus. We briefly comment the main characteristics of this entity.
文摘We present morphological findings observed from the study of a myxopapillary ependymoma located in the III ventricle. This tumor, which is a rare occurrence at this level, was observed in a 73-year-old woman with no relevant medical history who presented with obstructive hydrocephalus due to compression and blockage of the foramen of Monro. The good delineation of the lesion allowed its surgical excision, and histological examination of the material obtained after excisional biopsy revealed a glial neoplasm with a low degree of cytological malignancy that was strongly positive for glial fibrillary acidic protein (GFAP) as well as a myxopapillary architecture analogous to that observed in ependymomas of the filum terminale. Subsequent radiological examination allowed us to rule out a metastatic nature of the tumor, confirming its primary origin. We briefly discuss the case and review the main characteristics of this neoplasia, which is quite rare at the site identified in our patient.
