Radiation and Dust Sensor for Mars Environmental Dynamic Analyzer Onboard M2020 Rover.

The Radiation and Dust Sensor is one of six sensors of the Mars Environmental Dynamics Analyzer onboard the Perseverance rover from the Mars 2020 NASA mission. Its primary goal is to characterize the airbone dust in the Mars atmosphere, inferring its concentration, shape and optical properties. Thanks to its geometry, the sensor will be capable of studying dust-lifting processes with a high temporal resolution and high spatial coverage. Thanks to its multiwavelength design, it will characterize the solar spectrum from Mars' surface. The present work describes the sensor design from the scientific and technical requirements, the qualification processes to demonstrate its endurance on Mars' surface, the calibration activities to demonstrate its performance, and its validation campaign in a representative Mars analog. As a result of this process, we obtained a very compact sensor, fully digital, with a mass below 1 kg and exceptional power consumption and data budget features.

Calorimetric and dielectric studies of ferroelectric sodium nitrite confined in a nanoscale porous glass matrix.

Heat-capacity measurements of the sodium nitrite confined in a nanoscale porous glass matrix show that the intermediate incommensurate phase, present in the bulk, has disappeared and that the first-order ferroelectric transition becomes suppressed and gradual. The ferroelectric transition temperature is shifted considerably to lower temperatures. Two noncritical dielectric modes were observed; however, the observed giant growth of the dielectric constant on heating through the transition temperature TC is shown to be mainly due to the electrode polarization effect.

Expression of CD34, alpha-smooth muscle actin, and transforming growth factor beta1 in squamous intraepithelial lesions and squamous cell carcinoma of the larynx and hypopharynx.

AIM OF THE STUDY: There is increasing evidence that stromal reaction in cancer has an important diagnostic and prognostic significance. Recent studies have shown that CD34-positive stromal cells and myofibroblasts may play an important role in host response to invasive cancer. The aim of our study was to analyze the expression of CD34, alpha-smooth muscle actin (SMA), and transforming growth factor beta1 (TGFbeta1) in squamous intraepithelial lesions (SILs) and squamous cell carcinoma (SCC) of the larynx and hypopharynx, to establish their significance, and to elucidate the mechanism of myofibroblast formation. METHODS: Immunohistochemistry was performed on samples of 42 resected larynges and 12 laryngeal biopsies of SILs and SCC using antibodies against SMA, CD34, CD31, TGFbeta1, and TGFbeta1 receptors. The expression of TGFbeta1 mRNA was detected with RNA in situ hybridization using specific oligonucleotides for TGFbeta1. RESULTS: The stroma in normal laryngeal mucosa and SILs contained scattered CD34-positive cells, but there were no SMA-positive myofibroblasts. In contrast, the stroma of SCC contained SMA-positive myofibroblasts, but there were no CD34-positive stromal cells. This pattern of stromal reaction was also observed in the peritumoral zone. In adjacent normal tissue, there were CD34-positive stromal cells and no myofibroblasts. We found more intense TGFbeta1 expression in carcinoma cells than in the normal laryngeal epithelium and positive staining for both TGFbeta1 receptors on stromal cells of the normal mucosa. In SCC, many myofibroblasts expressed TGFbeta1 and both receptors for TGFbeta1. Expression of TGFbeta1 mRNA was similar to expression of TGFbeta1 protein. CONCLUSION: Our study shows that disappearance of CD34-positive stromal cells and appearance of SMA-positive stromal myofibroblasts are associated with transformation of laryngeal SILs to SCC. This pattern of stromal reaction was found not only in the tumor but also in the peritumoral zone, defined as a band of host tissue between the invasive tumor front and adjacent normal tissue. Our findings also support the suggestion that overproduced TGFbeta1 in carcinoma cells mediates one of the mechanisms of transformation of stromal cells to myofibroblasts in laryngeal carcinogenesis.

Colorectal carcinoma in endoscopic biopsies; additional histologic criteria for the diagnosis.

In endoscopic biopsies, desmoplastic stroma and/or tumor invasion of the submucosa are generally regarded as histologic features that allow for the diagnosis of colorectal carcinoma (CRC). They are not present in all endoscopic biopsies of CRC. We investigated tumor necrosis and invasion of adjacent normal mucosa for their usefulness as possible additional histologic criteria for CRC, and evaluated quantitatively the diagnostic reliability of each of the four aforementioned histologic features in routine biopsy practice. We analyzed 440 endoscopic biopsies of lesions endoscopically suspicious of CRC and compared them with 26 colorectal adenomas with malignant change and 344 colorectal adenomas. The slides were stained by H&E and the Kreyberg-Jareg trichrome method. The endoscopic histologic diagnoses were verified by histologic examination of surgically resected specimens. In endoscopic biopsies of CRC, desmoplastic stroma was found in 83.6% of the cases, tumor necrosis in 75.7%, submucosal invasion in 27.0%, and invasion of normal mucosa in 22.7%. When only one of the diagnostic features was present, there was a false positivity of 2.5-13.3%; however, the latter has fallen to 0.8% when two features were present, but disappeared when there were three or four histologic features. Adenomas with malignant change showed necrosis in 69.2% and invasion of adjacent mucosa in 15.3%. In adenomas, necrosis was present in 0.6% of the cases, desmoplastic stroma in 3.2%, and shallow erosions in 27.3%. The presence of tumor necrosis and invasion of normal mucosa were characteristic histologic features of CRC; therefore, they represent useful additional histologic criteria for the diagnosis of CRC in endoscopic biopsies. The reliability of the histologic diagnosis of CRC correlated with the number of the four aforementioned histologic features.