Search results for "Roca"

Synthesis of cyanoacetic acid by electrocatalytic carboxylation of chloroacetonitrile at a silver cathode

2008

Feasibility of Ultra-Short-Term Analysis of Heart Rate and Systolic Arterial Pressure Variability at Rest and during Stress via Time-Domain and Entro…

2022

Heart Rate Variability (HRV) and Blood Pressure Variability (BPV) are widely employed tools for characterizing the complex behavior of cardiovascular dynamics. Usually, HRV and BPV analyses are carried out through short-term (ST) measurements, which exploit ~five-minute-long recordings. Recent research efforts are focused on reducing the time series length, assessing whether and to what extent Ultra-Short-Term (UST) analysis is capable of extracting information about cardiovascular variability from very short recordings. In this work, we compare ST and UST measures computed on electrocardiographic R-R intervals and systolic arterial pressure time series obtained at rest and during both post…

Causal and Non-Causal Frequency Domain Assessment of Spontaneous Baroreflex Sensitivity after Myocardial Infarction

2020

Acute myocardial infarction (AMI) is thought to alter the baroreflex control of arterial pressure. We tested this hypothesis investigating the changes of the cardiovascular response after AMI in comparison with young and old healthy controls studied at rest and during head-up tilt, using causal and non-causal frequency domain measures of the baroreflex sensitivity. Our results indicate: (i) the importance of using a causal approach that takes into account not only feedback but also feedforward effects in the study of interactions between the heart period and the arterial pressure; (ii) the compromised capacity of baroreceptors to control SAP fluctuations in post-AMI patients, both at rest a…

Synergistic and Redundant Brain-Heart Information in Patients with Focal Epilepsy

2020

In this work, partial information decomposition (PID) was applied to the time series of heart rate and EEG amplitude variability to investigate the dynamical interactions in brain-heart coupling before and after epileptic seizures. From ECG and EEG signals collected on 23 children suffering from focal epilepsy, the RR intervals and the EEG variance at ipsilateral and contralateral temporal electrodes were computed in four different time windows before and after the seizures. Static PID was used to obtain redundant, unique and synergistic components of the total information shared between the series of RR and EEG variance. Results highlight, in the progression from preictal to postictal stat…

A portable multisensor system to assess cardiorespiratory interactions through photoplethysmography

2022

Nowadays, the ever-growing interest to health and quality of life of individuals and the advancements in electronic devices technology are pushing the development of portable and wearable biomedical devices able to pursue a minimally invasive monitoring of physiological parameters in daily-life conditions. Such devices can now carry out a real-time assessment of the subjects’ overall health status and possibly even detect ongoing diseases. In this context, we have designed and implemented a multisensor portable system able to perform synchronous real-time acquisitions of electrocardiographic (ECG), photoplethysmographic (PPG) and airflow breathing signals. We investigated cardiorespiratory …

Low-invasive multisensor real-time acquisition system for the assessment of cardiorespiratory and skin conductance parameters

2022

In recent years, the attention to the health and comfort of the individual, together with the electronic miniaturization progress, have led to an increased interest in the development of biomedical devices that are able to acquire a multitude of biomedical signals. Such devices should be wearable and comfortable during daily use, to be thus suitable for continuously monitoring psychophysical health states. In this context, we have designed and realized a portable biomedical device capable of real-time acquisition of electrocardiographic (ECG), photoplethysmographic (PPG), breathing and galvanic skin response (GSR) signals, for a noninvasive monitoring of multiple physiological parameters. T…

Gas phase behavior of radical cations of perfluoroalkyl-1,2,4-triazines: an experimental and theoretical study

2009

Electron ionization mass spectrometry and low-energy collision-induced decomposition reactions occurring in a tridimensional ion trap, together with density functional theory (DFT) calculations on neutrals, even- and odd-electron cations, have been used to study the gas-phase ion chemistry of a series of perfluoroalkyl-1,2,4-triazines. Loss of oxygen, due to thermal degradation occurring before ionization, likely involving the hydroxylamino group, has been observed. Compounds having a carbonyl group at position 6 of the triazine ring fragment in the source by elimination of NO followed by HF or CO. The decomposition pathways occurring due to CID experiments have shown interesting features d…

Synthesis of phosphine derivatives of [Fe2(CO)6(μ-sdt)] (sdt = SCH2SCH2S) and investigation of their proton reduction capabilities

2023

The reactions of [Fe2(CO)6(μ-sdt)] (1) (sdt = SCH2SCH2S) with phosphine ligands have been investigated. Treatment of 1 with dppm (bis(diphenylphosphino)methane) or dcpm (bis(dicyclohexylphosphino)methane) affords the diphosphine-bridged products [Fe2(CO)4(μ-sdt)(μ-dppm)] (2) and [Fe2(CO)4(μ-sdt)(μ-dcpm)] (3), respectively. The complex [Fe2(CO)4(μ-sdt)(κ2-dppv)] (4) with a chelating diphosphine was obtained by reacting 1 with dppv (cis-1,2-bis(diphenylphosphino)ethene). Reaction of 1 with dppe (1,2-bis(diphenylphosphino)ethane) produces [{Fe2(CO)4(μ-sdt)}2(μ-κ1-dppe)] (5) in which the diphosphine forms an intermolecular bridge between two diiron cluster fragments. Three products were obtaine…

Ostruzione polmonare ed aritmia respiratoria

2019

Il monitoraggio di pazienti tramite segnali fotopletismografici (PhotoPlethysmoGram, PPG) acquisiti sul polso, arteria radiale, piuttosto che sulla punta dell’indice, permette di ottenere un segnale più stabile e con maggiori informazioni, come la gittata cardiaca, la durata della contrazione ventricolare e la chiusura dell’aorta. In questo lavoro è presentata un’attività preliminare per rilevare condizioni come l’ostruzione polmonare e le apnee notturne. Si è indagato l’andamento dell’aritmia respiratoria in relazione ad eventuali difficoltà respiratorie. Per il momento ci si è limitati ad osservare soggetti sani e l’ostruzione è stata simulata facendo respirare i soggetti attraverso una c…

Study of the aryl hydrocarbon receptor mediated effects through in silico modeling and in vitro bioassays

2020

The aryl hydrocarbon receptor (AhR) is a cytoplasmatic sensor of diverse endogenous and exogenous substances. In a toxicological context, the former known as “dioxin receptor” has been investigated as a xenobiotic chemoreceptor and due to its roles in mediating carcinogenesis, endocrine disruption, among other immunological, hepatic, cardiovascular, and dermal toxicity mechanisms. The deep physiological implications of AhR in cellular proliferation, adhesion, division, differentiation, as well as in the reproductive, immunological and cardiovascular homeostasis have opened a new field of research in order to harness AhR’s pharmacological potential. Hence, AhR has become a therapeutic target…