Performance of CMOS imager as sensing element for a Real-time Active Pixel Dosimeter for Interventional Radiology procedures

Staff members applying Interventional Radiology procedures are exposed to ionizing radiation, which can induce detrimental effects to the human body, and requires an improvement of radiation protection. This paper is focused on the study of the sensor element for a wireless real-time dosimeter to be worn by the medical staff during the interventional radiology procedures, in the framework of the Real-Time Active PIxel Dosimetry (RAPID) INFN project. We characterize a CMOS imager to be used as detection element for the photons scattered by the patient body. The CMOS imager has been first characterized in laboratory using fluorescence X-ray sources, then a PMMA phantom has been used to diffuse the X-ray photons from an angiography system. Different operating conditions have been used to test the detector response in realistic situations, by varying the X-ray tube parameters (continuous/pulsed mode, tube voltage and current, pulse parameters), the sensor parameters (gain, integration time) and the relative distance between sensor and phantom. The sensor response has been compared with measurements performed using passive dosimeters (TLD) and also with a certified beam, in an accredited calibration centre, in order to obtain an absolute calibration. The results are very encouraging, with dose and dose rate measurement uncertainties below the 10% level even for the most demanding Interventional Radiology protocols

Effect of physical properties of granular sustainable-porous materials on water content measurements by using a low-cost sensor

Soil water content has a primary importance in several scientific fields involving the geotechnical, hydrological agronomic, ecological, and biological properties of the soil mass. In recent years, several techniques for the determination of soil water content in the laboratory and in situ have been proposed and developed. The application of these techniques and adopted measurement systems to different soil types is widely discussed in the literature, thus highlighting a nontrivial issue deserving further experimental research. This paper presents the results of the application to granular sustainable materials of a capacitive sensor originally developed for soil water content measurement. In particular, the application regards coffee ground samples with two grain size distributions prepared dry and at increasing water content in the range of 5 –25 %, at different initial voids rations. The effect of initial voids ratio and grain size distribution is also examined

Integrated sensor system for DNA amplification and separation based on thin film technology

This paper presents the development of a lab-on-chip, based on thin-film sensors, suitable for DNA treatments. In particular, the system performs on-chip DNA amplification and separation of double-strand DNA into single-strand DNA, combining a polydimethylsiloxane microfluidic network, thin-film electronic devices, and surface chemistry. Both the analytical procedures rely on the integration on the same glass substrate of thin-film metal heaters and amorphous silicon temperature sensors to achieve a uniform temperature distribution (within ±1 °C) in the heated area and a precise temperature control (within ±0.5 °C). The DNA separation also counts on the binding between biotinylated dsDNA and a layer of streptavidin immobilized into a microfluidic channel through polymer-brushes-based layer. This approach results in a fast and low reagents consumption system. The tested DNA treatments can be applied for carrying out the on-chip systematic evolution of ligands by exponential enrichment process, a chemistry technique for the selection of aptamers

Antifungal Activity of Decyl Gallate against Several Species of Pathogenic Fungi

This work aims to demonstrate that the gallic acid structure modification to the decyl gallate (G14) compound contributed to increase the antifungal activity against several species of pathogenic fungi, mainly, Candida spp., Cryptococcus spp., Paracoccidioides spp., and Histoplasma capsulatum, according to standardized microdilution method described by Clinical Laboratory Standard Institute (CLSI) documents. Moreover this compound has a particularly good selectivity index value, which makes it an excellent candidate for broad-spectrum antifungal prototype and encourages the continuation of subsequent studies for the discovery of its mechanism of action