1,721,059 research outputs found
Semi-empirical Anticoagulation Model (SAM): Dose prediction during warfarin therapy
No full text: Management of oral anticoagulant therapy is essential to ensure a good quality of life for patients. To assist clinicians, several computerized dosing algorithms were developed to determine optimal anticoagulant doses. However, these algorithms have several limitations that can lead to inaccuracies in dosing recommendations. To overcome some of these challenges, this paper proposes a warfarin dose prediction algorithm using individual patient sensitivity analysis. The proposed algorithm is designed to account for factors that influence an individual's response to warfarin, allowing it to more accurately adjust and optimize dosing. It is based on the Semi-empirical Anticoagulation Model (SAM), but has been extended to incorporate stochastic process analysis. This allows the algorithm to assess the probability of events that could change the relationship between the International Normalized Ratio (INR) and the therapy administered. To evaluate the effectiveness of the algorithm, a retrospective observational study of 1796 patients was conducted over one year. The study compared the doses of warfarin administered in clinical practice with those suggested by the algorithm. Percentage Bland-Altman Analysis was used to assess accuracy, which showed that the algorithm had an average accuracy of (3.24±25.80)%. When compared to other algorithms in the literature, which showed an accuracy of (5.73±60.9)%, the proposed algorithm showed significantly better accuracy. The improved accuracy of the proposed algorithm allows for more flexible and precise adjustments to therapy, resulting in an INR closer to the target range with less variability. This ultimately improves patient safety and the overall quality of life for those suffering from venous thromboembolism
Polymer-grafted QCM chemical sensor and application to heavy metal ions real time detection
No full textA flow type quartz crystal microbalance (QCM) chemical sensor was
developed for monitoring heavy metal ions in aqueous solutions (that is suitable
for environmental monitoring). The sensor is based upon surface chelation of the
metal ions at multifunctional polymer modified gold electrodes on 9 MHz AT-cut
quartz resonators, functioning as a QCM. New processes have been developed which
enable to obtain surface-modified gold electrodes with high heavy metal ions
complexing ability. These polymer grafted QCM sensors can selectively adsorb heavy
metal ions, such as copper, lead, chrome and cadmium, from solution over a wide
range from 0.01 to 1000 ppm concentration by complexation with functional groups
in the polymers. Cations typically present in natural water did not interfere with
the detection of heavy metals. X-Ray Reflectivity (XRR) and Total Reflection X-ray
Fluorescence (TXRF) were carried out to characterise the unmodified and modified
gold surfaces as well as to verify the possibility to selectively bond and remove
metal ions
Multi-element analysis of vegetal foodstuff by means of low power total reflection X-ray fluorescence (TXRF) spectrometry
No full textIn this work, an analytical methodology in combination with a low power benchtop total reflection X-ray fluorescence (TXRF) system has been developed for multi-elemental analysis of vegetal materials. An easy and rapid sample preparation consisting in suspending 20 mg of sample in de-ionized water showed to be the most suitable for this kind of samples. However, for comparison purposes, two digestion procedures were also applied. A set of fifteen certified reference materials and three real vegetal samples were employed for the quantitative determination of K, Ca, Mn, Fe, Cu, Zn, Br, Rb, Sr, Pb, As and Sn. All the parameters affecting sample preparation and TXRF measurements conditions were carefully evaluated. Accurate and precise results were obtained for mid-high Z elements (Mn-Sr) using internal standardization as quantification approach, while for light Z elements (K and Ca), due to absorption effects, an improvement of analytical results by external calibration was necessary
Spectrochimica Acta Part B Virtual Special Issue on the 17th International Conference on Total Reflection X-Ray Fluorescence Analysis and Related Methods
No full textThis Virtual Special Issue (VSI) provides an overview of the most
novel and original research presented during the 17th International
Conference on Total Reflection X-Ray Fluorescence Analysis and Related
Methods (TXRF 2017).
The TXRF 2017was held on September 19–22, 2017 in Brescia, Italy.
The aimof the conferencewas to bring together experts, users andmanufacturers
of total reflection X-ray fluorescence (TXRF) spectrometers
to present and discuss recent advances, research results and perspectives.
Emphasis is given to potential applications of TXRF and related
methods for trace and ultra-trace analysis in environmental, semiconductor,
nanomaterials, food, cosmetics, fuels, energy and archaeometry,
biology, synchrotron radiation, instrument and modelling fields.
TXRF2017 was an important and effective opportunity for substantial
discussions, exchange of knowledge and experience.
A total of 89 participants from 22 countries attended TXRF 2017, including
4 plenary lectures, 16 invited speakers, 54 oral presentations
and 49 poster presentations
A green and simple process to develop conductive polyurethane foams for biomedical applications
No full textIn this work, conductive polyurethane (PU) foam is developed to be used as skin electrode for long term use medical devices. Water based polyurethane and other eco-friendly substances are selected to implement a green process, where the composite is produced in the shape of film and foam, by a transfer coating process. Different formulation and process materials are consid- ered to evaluate the effect on surface resistivity and percolation threshold. The time stability, water vapor transmission, elongation and stress-strain properties, are studied. Results show that the realized material is suitable to be used as electrode for biomedical applications
Fabrication and investigation of gas sensing properties of Nb-doped TiO2 nanotubular arrays
No full textSynthesis of Nb-containing titania nanotubular arrays at room temperature by electrochemical anodization is reported. Crystallization of pure and Nb-doped TiO2 nanotubes was carried out by post-growth annealing at 400 °C. The morphology of the tubes obtained was characterized by scanning electron microscopy (SEM). Crystal structure and composition of tubes were investigated by glancing incidence x-ray diffraction (GIXRD) and total reflection x-ray fluorescence (TXRF). For the first time gas sensing characteristics of Nb-doped TiO2 nanotubes were investigated and compared to those of undoped nanotubes. The functional properties of nanotubular arrays towards CO, H2, NO2, ethanol and acetone were tested in a wide range of operating temperature. The introduction of Nb largely improves conductivity and enhances gas sensing performances of TiO2 nanotubes
IN SITU XRD CHARACTERIZATION OF HYDROGEN DESORPTION FROM ELECTROCHEMICALLY DEPOSITED PD COATING
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Laboratory two-dimensional X-ray microdiffraction technique: a support for authentication of an unknown Ghirlandaio painting
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