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This study addressed fire‐induced changes in topsoil organic matter (SOM) from a eucalypt plantation in Portugal over 2 years by using three complementary biogeochemical techniques: elemental analysis, analysis of biomarkers from the total extractable lipids (TLE) and solid state 13C nuclear magnetic resonance (NMR) spectroscopy. Direct wildfire effects included a marked decrease in soil total organic...
The goal of this paper is to construct accurate three-dimensional models from atomic structures that can be compared to Electron Microscopy volumes. They, in their turn, can be used to solve fitting and docking problems as well as to generate ground-truth models for the development of image processing algorithms. We use Electron Atomic Scattering Factor (EASF) along with a careful filter design to...
Photodynamic therapy is a type of phototherapy that involves the administration of a photosensitizer drug followed by a local illumination with light of specific wavelength. In the presence of oxygen molecules, the light illumination of photosensitizer can activate the production of reactive oxygen species which yield the death of target cells. In order to obtain the best therapy response, it can...
We report the results of applying several deconvolution methods to estimate fluorescence decay curves and fluorescence lifetimes. The methods are applied to time-resolved fluorescence signals measured with a homemade spectrofluorometer. We measured the fluorescence emitted by three substances with known lifetimes: fluoresceine (4.03 ns), rhodamine 6G (4.08 ns), and rhodamine B (1.68 ns). Also we measured...
Photodynamic therapy is a well know treatment based on the interaction of light with a photosensitizer drug and oxygen. It has been used for the treatment of certain diseases, especially cancer. One of the major problems in the implementation of the therapy is the use of lasers as light sources which increases the cost of the therapy. This is why we propose the development of photodynamic therapy...
This paper presents an adaptive 1.2-V 90-nm CMOS cascade two-stage (2-2) SC ΣΔ modulator with 3-level quantization and unity signal transfer function in both stages. The chip reconfigures its loop filter order (either 2nd or 4th-order), clock frequency (from 40 to 240 MHz) and scales power according to the required specifications for different wireless standards, covering: GSM, Bluetooth, GPS, UMTS,...
This paper analyses the use of folded cascode Low Noise Amplifiers (LNAs) for the implementation of multistandard wireless transceivers. The proposed LNA consists of a two-stage topology made up of a folded cascode and simple-stage amplifiers that use NMOS-varactor based tuning networks to make the operating frequency continuously programmable. The circuit has been designed and implemented in a 90-nm...
This paper presents the development of an irradiation system for photodynamic therapy with temperature control. The system allows the application of an optical radiation whose wavelength is 630nm, using light-emitting high power diodes. The developed system has a power control to irradiate the target tissue with an adequate power density. A temperature sensor is placed in the irradiated sample to...
The Differential Opitcal Absorption Spectroscopy (DOAS) is a technique to measure pollutant emissions like SO2, NO2 from point sources and total fluxes in the atmosphere. Passive DOAS systems use the solar radiation as the light source. Measurements with such systems can be made in situ and in real time. The goal of this work is to report the design and implementation of hardware and software of a...
In this paper we present the development of a portable spectrofluorometer with USB interface for in vivo measurements in biological tissue. The equipment consists of a mini-spectrometer HR4000CG-UV-NIR, with a working range from 200 to 1100 nm with a resolution of 0.5 nm FWHM. As the excitation source a light emitting diode at 365 nm, with maximum radiant power of 200 mW was used. A bifurcated fiber...
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