| 1. |
|
|
| 2. |
- Correale, Michele, et al.
(author)
-
Circulating biomarkers in pulmonary arterial hypertension : an update
- 2024
-
In: Biomolecules. - : MDPI. - 2218-273X. ; 14:5
-
Research review (peer-reviewed)abstract
- Pulmonary arterial hypertension (PAH) is a rare subtype of group 1 pulmonary hypertension (PH) diseases, characterized by high pulmonary artery pressure leading to right ventricular dysfunction and potential life-threatening consequences. PAH involves complex mechanisms: vasoconstriction, vascular remodeling, endothelial dysfunction, inflammation, oxidative stress, fibrosis, RV remodeling, cellular hypoxia, metabolic imbalance, and thrombosis. These mechanisms are mediated by several pathways, involving molecules like nitric oxide and prostacyclin. PAH diagnosis requires clinical evaluation and right heart catheterization, confirming a value of mPAP ≥ 20 mmHg at rest and often elevated pulmonary vascular resistance (PVR). Even if an early and accurate diagnosis is crucial, PAH still lacks effective biomarkers to assist in its diagnosis and prognosis. Biomarkers could contribute to arousing clinical suspicion and serve for prognosis prediction, risk stratification, and dynamic monitoring in patients with PAH. The aim of the present review is to report the main novelties on new possible biomarkers for the diagnosis, prognosis, and treatment monitoring of PAH.
|
|
| 3. |
- Dini, Francesca, et al.
(author)
-
Chemical sensitivity of self-assembled porphyrin nano-aggregates
- 2009
-
In: NANOTECHNOLOGY. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 20:5, s. 055502-
-
Journal article (peer-reviewed)abstract
- Nanostructured molecular assemblies may provide additional sensing properties not found in other arrangements of the same basic constituents. Among three-dimensional structures, nanotubes are particularly appealing for applications as chemical sensors, because of the potential inclusion of different guests inside the cavity or the induced modification of the skeletal interaction after analyte binding. Porphyrins are a class of compounds characterized by brilliant sensing properties, appearing also in non-ordered solid-state aggregates. In recent years, it was reported that aggregation of oppositely charged porphyrins led to the formation of self-assembled nanotubes and in this paper their sensing properties, both in solution and in the solid state, have been investigated. The interactions of porphyrin nanotubes with guest molecules have been monitored by following the changes in their UV-vis spectra. The results obtained have been exploited to build up a sensing platform based on a computer screen as a light source and a digital camera as detector. Porphyrin nanostructures exhibited an enhanced sensitivity to different compounds with respect to those shown by single porphyrin subunits. The reason for the increased sensitivity may be likely found in an additional sensing mechanism related to the modulation of the strength of the forces that keep the supramolecular ensemble together.
|
|
| 4. |
- Dini, Francesca, et al.
(author)
-
Combining porphyrins and pH indicators for analyte detection
- 2015
-
In: Analytical and Bioanalytical Chemistry. - : Springer. - 1618-2642 .- 1618-2650. ; 407:14, s. 3975-3984
-
Journal article (peer-reviewed)abstract
- High sensitivity and cross-selectivity are mandatory properties for sensor arrays. Although metalloporphyrins and pH indicators are among the most common and appropriate choices for the preparation of optical sensor arrays, the sensitivity spectrum of these dyes is limited to those analytes able to induce an optical response. To extend the receptive field of optical sensors, we explore the design of composite materials, where the molecular interaction among the subunits enriches their sensing working mechanisms. We demonstrate that blends of single metalloporphyrins and pH indicators, tested with a transduction apparatus based on ubiquitous and easily available hardware, can be endowed with sensing properties wider than those of single constituents, enabling the recognition of a broad range of volatiles.
|
|
| 5. |
- Dini, Francesca, et al.
(author)
-
Computer screen assisted digital photography
- 2013
-
In: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 179:SI, s. 46-53
-
Journal article (peer-reviewed)abstract
- The computer screen photo-assisted techniques (CSPT) have been developed during the last 10 years through an extensive collaboration between University of Rome "Tor Vergata" and Linkoping University in Sweden. CSPT has thus evolved into a concept we now call computer screen assisted digital photography, yielding detailed information about the interaction between color indicators and (volatile) analytes. In the present paper, we give a brief summary of the CSPT concept and its connection to digital photography. We concentrate, however, on the most recent results, which were obtained by using most of the degrees of freedom offered by a computer screen as a light source and a digital (web) camera as a detector. Thus, we describe in detail recent experiments on cotton yarns impregnated with color indicators for volatile organic molecules. The interaction between the color indicators and molecules, like trimethylamine, was investigated by CSPT in high dynamic imaging together with a background noise limiting algorithm. It is shown that the simultaneous use of the last two additions to the CSPT concept considerably enhances the chemical sensing ability of CSPT. It is concluded that the collaboration between Rome and Linkoping has generated a useful platform for further developments of chemical analysis with a ubiquitous instrumentation, a (computer) screen and a web camera. This technique is aimed at facilitating the assembly of opto-chemical sensors with evident benefits in the reduction of cost of sensor systems and in an increased integrability with the existent telecommunication infrastructures.
|
|
| 6. |
- Dini, Francesca, et al.
(author)
-
Data processing for image-based chemical sensors: unsupervised region of interest selection and background noise compensation
- 2012
-
In: Analytical and Bioanalytical Chemistry. - : Springer Verlag (Germany). - 1618-2642 .- 1618-2650. ; 402:2, s. 823-832
-
Journal article (peer-reviewed)abstract
- Natural olfaction suggests that numerous replicas of small sensors can achieve large sensitivity. This concept of sensor redundancy can be exploited by use of optical chemical sensors whose use of image sensors enables the simultaneous measurement of several spatially distributed indicators. Digital image sensors split the framed scene into hundreds of thousands of pixels each corresponding to a portion of the sensing layer. The signal from each pixel can be regarded as an independent sensor, which leads to a highly redundant sensor array. Such redundancy can eventually be exploited to increase the signal-to-noise ratio. In this paper we report an algorithm for reduction of the noise of pixel signals. For this purpose, the algorithm processes the output of groups of pixels whose signals share the same time behavior, as is the case for signals related to the same indicator. To define these groups of pixels, unsupervised clustering, based on classification of the indicator colors, is proposed here. This approach to signal processing is tested in experiments on the chemical sensitivity of replicas of eight indicators spotted on to a plastic substrate. Results show that the groups of pixels can be defined independently of the geometrical arrangement of the sensing spots, and substantial improvement of the signal-to-noise ratio is obtained, enabling the detection of volatile compounds at any location on the distributed sensing layer.
|
|
| 7. |
- Dini, Francesca, et al.
(author)
-
Polymer matrices effects on the sensitivity and the selectivity of optical chemical sensors
- 2011
-
In: SENSORS AND ACTUATORS B-CHEMICAL. - : Elsevier Science B.V., Amsterdam.. - 0925-4005. ; 154:2, s. 220-225
-
Journal article (peer-reviewed)abstract
- Polymers are commonly used in optical chemical sensors as inert supports for indicator dyes keeping the molecules apart to allow for exposure to analytes and to maintain the peculiar optical properties of the sensitive dyes. However, the partitioning properties of polymers may play a significant role in determining the sensitivity of the sensors. Herewith, the properties of a single dye blended with different polymers have been studied through optical absorbance changes elicited by the exposure to organic vapors. Results show that the partitioning properties of polymers modulate the response of the dye and confer a combinatorial selectivity to the system, allowing for the recognition of vapors.
|
|
| 8. |
- Dini, Francesca, et al.
(author)
-
Polymers with embedded chemical indicators as an artificial olfactory mucosa
- 2010
-
In: ANALYST. - : Royal Society of Chemistry. - 0003-2654. ; 135:6, s. 1245-1252
-
Journal article (peer-reviewed)abstract
- Physiological investigations suggest that the olfactory mucosa probably plays an ancillary role in the recognition of odours introducing a sort of chromatographic separation that, together with the zonal distribution of olfactory receptors, gives place to selective spatio-temporal response patterns. It has been recently suggested that this behaviour may be simulated by chemical sensors embedded in continuous polymer layers. In this paper, in analogy to the biology of olfaction, a simple and compact platform able to separate and detect gases and vapours on the basis of their diffusion properties is proposed. In such a system, broadly selective colour indicators, such as metalloporphyrins, are embedded in continuous layers of polymers with different sorption properties. The exposure to various alcohols and amines shows that the porphyrins are mainly responsible for the recognition of the molecular family, while the occurring spatio-temporal signal patterns make possible the identification of the individual chemical species.
|
|
| 9. |
- Dini, Francesca, et al.
(author)
-
Volatile Emissions from Compressed Tissue
- 2013
-
In: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 8:7
-
Journal article (peer-reviewed)abstract
- Since almost every fifth patient treated in hospital care develops pressure ulcers, early identification of risk is important. A non-invasive method for the elucidation of endogenous biomarkers related to pressure ulcers could be an excellent tool for this purpose. We therefore found it of interest to determine if there is a difference in the emissions of volatiles from compressed and uncompressed tissue. The ultimate goal is to find a non-invasive method to obtain an early warning for the risk of developing pressure ulcers for bed-ridden persons. Chemical analysis of the emissions, collected in compresses, was made with gas-chromatography – mass spectrometry and with a chemical sensor array, the so called electronic nose. It was found that the emissions from healthy and hospitalized persons differed significantly irrespective of the site. Within each group there was a clear difference between the compressed and uncompressed site. Peaks that could be certainly deemed as markers of the compression were, however, not identified. Nonetheless, different compounds connected to the application of local mechanical pressure were found. The results obtained with GC-MS reveal the complexity of VOC composition, thus an array of non-selective chemical sensors seems to be a suitable choice for the analysis of skin emission from compressed tissues; it may represent a practical instrument for bed side diagnostics. Results show that the adopted electronic noses are likely sensitive to the total amount of the emission rather than to its composition. The development of a gas sensor-based device requires then the design of sensor receptors adequate to detect the VOCs bouquet typical of pressure. This preliminary experiment evidences the necessity of studies where each given person is followed for a long time in a ward in order to detect the insurgence of specific VOCs pattern changes signalling the occurrence of ulcers.
|
|
| 10. |
- Guanais Goncalves, Carla, et al.
(author)
-
Detection of diverse potential threats in water with an array of optical sensors
- 2016
-
In: Sensors and actuators. B, Chemical. - : ELSEVIER SCIENCE SA. - 0925-4005 .- 1873-3077. ; 236, s. 997-1004
-
Journal article (peer-reviewed)abstract
- Optical sensor arrays are widely used for sensing the evolution and the identification of complex patterns of chemicals either in air or in water. This popularity stems from the fact that low-cost, ready-to-use optical devices, made available by the current commercial development of electronics commodities, are complemented by a number of low-cost chemical indicators, suitable for a wide range of applications. Among them, pH indicators, and metalloporphyrins make a solid library of molecules that can be adequately assembled for many different tasks. Here, such an array is used for the identification of toxic compounds of different origin that may be released in water distribution systems as a consequence of either accidents or deliberated contaminations. The compounds considered are intermediate products of chemical industry (dimethyl methylphosphonate and cyclohexanone), drugs (5-Fluorouracil and piperazine) and pesticides (imidacloprid and paraoxon). Results show that the sensors are sensitive, but with low selectivity, in the interval from 10(-7) mol L-1 to 10(-4) mol L-1. The sensor signals show a linear correlation with the logarithm of the concentration. Although the limited selectivity of individual sensors, the different sensitivity patterns allow for a clear identification of the compounds, independent of their concentration.(C) 2016 Elsevier B.V. All rights reserved.
|
|
