Determination of Plasma Antioxidant Power in Capillary Blood through the Innovative system PAT (Plasma Antioxidant Test)

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Global assessment of oxidative stress: analysis, causes and effects

Alterazioni dello equilibrio redox fisiologico portano allo sviluppo della condizione denominata stress ossidativo. Tale condizione, legata a vario titolo a svariate patologie, comporta l'ossidazione delle principali macromolecole, con conseguente perdita di funzionalità delle stesse. Di importanza fondamentale risulta la possibilità di conoscere e valutare l'equilibrio redox, mediante appositi test analitici, sviluppati e validati, oltre che alla necessità dia avere un bagaglio culturale adatto alla valutazione dello stress ossidativo.Changes in the physiological redox balance lead to the development of the condition called oxidative stress. This condition, linked to various pathologies, involves the oxidation of the main macromolecules, resulting in a loss of functionality of the same. Of crucial importance is the ability to know and evaluate the redox balance, by means of specific analytical tests, developed and validated, as well as the need to have a cultural baggage suitable for the assessment of oxidative stress

Plasma Oxidative Stress in Patients With Chronic Vascular Cutaneous Ulcers

Oxidative stress is hypothesized to be one of the main causes of the pathophysiologic alterations observed during impaired healing of wounds. In the present study, we aimed to measure systemic levels of free radicals in blood and anti-oxidant (AO) activity in the plasma of patients with chronic ulcers (venous stasis ulcers and arterial insufficiency ulcers) of lower extremities (CULEs). Oxidants and AO activity were measured in eighty-five consecutive patients with CVSUs of the lower extremities as they arrived randomly for routine visits to our ambulatory clinic. Values of oxidant and AO status in patients with CULEs were significantly different from normal. No significant differences in oxidant and AO values were found between patients with arterial ulcers or those with venous ulcers. A significant difference was found in AO values of diabetic patients with chronic venous ulcers compared with non-diabetic patients with chronic venous ulcers. No significant differences were observed when evaluating oxidant/AO values and smoking habits. Precise reasons why the association of diabetes and venous (but not arterial) ulcers was correlated with defective AO status in plasma are not known. Other data were also intriguing: diminished AO activity was observed in female patients, no significant differences in oxidant and values were found between patients with arterial ulcers or those with venous ulcers, no significant correlation was found between age and oxidant, as well as no significant differences were observed when evaluating oxidant/AO values and smoking habits

DSSC anode: tailoring crystal shape/phase stability of anatase nanopowders and their use in paste formulation

Among these, anatase nano-rods are used as photo-anode in the Dye Sensitized Solar Cells (DSSC) which have been demonstrated to be a promising, cost-effective alternative to conventional solid semiconducting solar cells for production of electrical energy [2]. Parameters such as shape, size and phase type of titania nanocrystals, that can be optimized recurring to different synthesis methods [3], influence the surface area of the nanoTiO2 and therefore the amount of sensitizing dye absorbed [4,5] that is strictly connected to the DSSC performance. Anyhow, despite the large number of studies on the anatase-to-rutile transformation (A-R) [6] and ab-initio calculations of the effects of crystal shape on anatase stability relative to rutile [7] the role of nanoparticle shape in DSSC are still to be clarified. The present study reports the synthesis of shape- and size-controlled anatase nanorods, their characterization as a function of thermal treatment and their use for preparation of a photo-anode paste. Anatase nanorods (Figure 1) were synthesized by a procedure encompassing hydrolysis of a TiO2 precursor, dispersion in high boiling organic solvent and suitable workup. By only changing the hydrolysis of titanium dioxide precursor, anatase nanorods with two different aspect ratios were obtained. These samples were then subjected to stepwise heating in the range form RT to 1000°C, and the variation of crystal shape, size and titania phase were monitored by powder X-ray diffraction and Rietveld refinements. A paste was made starting from a sample of anatase powder (labeled “SF”) having a surface area higher than the commercial nanotitania products (e.g. Degussa P25®). Each paste was prepared with an amount of TiO2 content of about 10-20% wt/wt. The starting raw material was obtained from a nanosuspension washed with a controlled pH value aqueous solution dried by spray drying. The powder was then mixed with a solvent (terpineol), a co-solvent (2-ethyl-1-hexanol), a binder and a dispersant, under mechanical stirring at room temperature. Such a prepared material was further added with ethanol and mixed for a time needed to ensure the best homogeneity. The paste so obtained was then dried under vacuum to eliminate the low boiling solvents. A strong milling of the paste by a three roll mill (EXAKT) was performed to ensure the grip of the TiO2 thick layer to the conductive glass (FTO) even after heat treatment in the sintering furnace. The adhesion of the fired paste to the support glass was checked by scanning electron microscopy. The paste applied in DSSC devices has been irradiated with solar lamp to allow the calculation of current values of the closed circuit. The values compared with paste made with the commercial nanotitania powder, show an improvement from 20% to 50% in terms of photo-current generated by the cell. Reference: [1] U. Diebold, Surface Science Reports, 2003, 48, 53-229. [2] B. O’Regan, M. Grätzel, Nature, 1991, 353, 737. [3] M. Fernandez-Garcıa, X. Wang, C. Belver, J.C. Hanson, J.A. Rodriguez, J. Phys. Chem. C, 2007, 111, 674-682. [4] Md. K. Nazeeruddin, S. M. Zakeeruddin, R. Humphry-Baker, M. Jirousek, P. Liska, N. Vlachopoulos, V. Shklover, C.-H. Fischer, and M. Grätzel, Inorg. Chem, 1999, 38, 6298-6305. [5] S. Ito, P. Chen, P. Comte, M. K. Nazeeruddin, P. Liska, P. Péchy, and M. Grätzel, Progress in Photovoltaics, 2007, 15, 603- 612. [6] H. Zhang, J.F. Banfield, Chem. Mater., 2005, 17, 3421-3425. [7] A. S. Barnard, L. A. Curtiss, NanoLetters, 2005, 5, 1261-126

Sensing Optimum in the Raw: Leveraging the Raw-Data Imaging Capabilities of Raspberry Pi for Diagnostics Applications

Single-board computers (SBCs) and microcontroller boards (MCBs) are extensively used nowadays as prototyping platforms to accomplish innovative tasks. Very recently, implementations of these devices for diagnostics applications are rapidly gaining ground for research and educational purposes. Among the available solutions, Raspberry Pi represents one of the most used SBCs. In the present work, two setups based on Raspberry Pi and its CMOS-based camera (a 3D-printed device and an adaptation of a commercial product named We-Lab) were investigated as diagnostic instruments. Different camera elaboration processes were investigated, showing how direct access to the 10-bit raw data acquired from the sensor before downstream imaging processes could be beneficial for photometric applications. The developed solution was successfully applied to the evaluation of the oxidative stress using two commercial kits (d-ROM Fast; PAT). We suggest the analysis of raw data applied to SBC and MCB platforms in order to improve results

Sensing Optimum in the Raw: Leveraging the Raw-Data Imaging Capabilities of Raspberry Pi for Diagnostics Applications

Single-board computers (SBCs) and microcontroller boards (MCBs) are extensively used nowadays as prototyping platforms to accomplish innovative tasks. Very recently, implementations of these devices for diagnostics applications are rapidly gaining ground for research and educational purposes. Among the available solutions, Raspberry Pi represents one of the most used SBCs. In the present work, two setups based on Raspberry Pi and its CMOS-based camera (a 3D-printed device and an adaptation of a commercial product namedWe-Lab) were investigated as diagnostic instruments. Different camera elaboration processes were investigated, showing how direct access to the 10-bit raw data acquired from the sensor before downstream imaging processes could be beneficial for photometric applications. The developed solution was successfully applied to the evaluation of the oxidative stress using two commercial kits (d-ROM Fast; PAT). We suggest the analysis of raw data applied to SBC and MCB platforms in order to improve results

The Prognostic Value of Derivatives-Reactive Oxygen Metabolites (d-ROMs) for Cardiovascular Disease Events and Mortality:A Review

Oxidative stress participates in the development and exacerbation of cardiovascular diseases (CVD). The ability to promptly quantify an imbalance in an individual reductive-oxidative (RedOx) state could improve cardiovascular risk assessment and management. Derivatives-reactive oxygen metabolites (d-ROMs) are an emerging biomarker of oxidative stress quantifiable in minutes through standard biochemical analysers or by a bedside point-of-care test. The current review evaluates available data on the prognostic value of d-ROMs for CVD events and mortality in individuals with known and unknown CVD. Outcome studies involving small and large cohorts were analysed and hazard ratio, risk ratio, odds ratio, and mean differences were used as measures of effect. High d-ROM plasma levels were found to be an independent predictor of CVD events and mortality. Risk begins increasing at d-ROM levels higher than 340 UCARR and rises considerably above 400 UCARR. Conversely, low d-ROM plasma levels are a good negative predictor for CVD events in patients with coronary artery disease and heart failure. Moreover, combining d-ROMs with other relevant biomarkers routinely used in clinical practice might support a more precise cardiovascular risk assessment. We conclude that d-ROMs represent an emerging oxidative-stress-related biomarker with the potential for better risk stratification both in primary and secondary cardiovascular prevention