Publications by authors named "C Negri"

165 Publications

Accuracy of CGM Systems During Continuous and Interval Exercise in Adults with Type 1 Diabetes.

J Diabetes Sci Technol 2021 Jun 11:19322968211023522. Epub 2021 Jun 11.

Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University and Hospital of Verona, Verona, Italy.

Background: continuous glucose monitoring systems (CGMs) play an important role in the management of T1D, but their accuracy may reduce during rapid glucose excursions. The aim of study was to assess the accuracy of recent rt-CGMs available in Italy, in subjects with T1D during 2 sessions of physical activity: moderate continuous (CON) and interval exercise (IE).

Method: we recruited 22 patients with T1D, on CSII associated or integrated with a CGM, to which a second different sensor was applied. Data recorded by CGMs were compared with the corresponding plasma glucose (PG) values, measured every 5 minutes with the glucose analyzer. To assess the accuracy of the CGMs, we evaluated the Sensor Bias (SB), the Mean Absolute Relative Difference (MARD) and the Clarke error grid (CEG).

Results: a total of 2355 plasma-sensor glucose paired points were collected. Both average plasma and interstitial glucose concentrations did not significantly differ during CON and IE. During CON: 1. PG change at the end of exercise was greater than during IE ( = .034); 2. all sensors overestimated PG more than during IE, as shown by SB ( < .001) and MARD ( < .001) comparisons. Classifying the performance according to the CEG, significant differences were found between the 2 sessions in distribution of points in A and B zones.

Conclusions: the exercise affects the accuracy of currently available CGMs, especially during CON, suggesting, in this circumstance, the need to maintain blood glucose in a "prudent" range, above that generally recommended. Further studies are needed to investigate additional types of activities.
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http://dx.doi.org/10.1177/19322968211023522DOI Listing
June 2021

Dynamic Voltage Restorer (DVR) with a novel robust control strategy.

ISA Trans 2021 Apr 13. Epub 2021 Apr 13.

Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, TX 79409, USA. Electronic address:

With the advancement of technology, electric equipment and loads have become more sensitive to problems related to power quality, such as voltage sag, swell, imbalances, and harmonics. To detect faults and to protect sensitive loads from these voltage distortions, a Dynamic Voltage Restorer (DVR) series compensator is among the best available cost-effective solutions. One of the main goals of the DVR is to achieve a control structure that is robust, stable, and can handle properly the disturbances (e.g., grid voltage issues, load current, and fluctuations at the DC link voltage) and model uncertainties (e.g., inverters and filter parameters). In this work, a novel framework control strategy based on Uncertainty and Disturbance Estimator (UDE) is proposed to improve the response of the DVR to properly compensate the load voltage under a variety of power quality issues, particularly the ones associated with the grid voltage disturbances. Additionally, the stability of the proposed control system is analyzed and validated using the Lyapunov stability theory. The advantages of the new control system are robustness, simplified design, good harmonic rejection, low tracking error, fast response, and sinusoidal reference tracking without the need for voltage transformations or specific frequency tuning (e.g., abc-dq0 and Proportional-Resonant). This research uses the MATLAB/Simulink software to validate the effectiveness of the proposed scheme under a diverse set of conditions with no control limitations. Moreover, the designed controller is tested under real conditions using Hardware-In-the-Loop (HIL) validation with OPAL-RT real-time simulator coupled with a TI Launchpad microcontroller. The results demonstrate a good performance of the proposed control strategy for a quick transient response and a great harmonic rejection when subject to grid voltage distortions.
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http://dx.doi.org/10.1016/j.isatra.2021.04.010DOI Listing
April 2021

Glomerular filtration rate decline in T2DM following diagnosis. The Verona newly diagnosed diabetes study-12.

Diabetes Res Clin Pract 2021 May 22;175:108778. Epub 2021 Mar 22.

Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University and Hospital Trust of Verona, Verona, Italy.

Aims: Nephropathy is a complication of type 2 diabetes, with increased albuminuria and reduced glomerular filtration rate (GFR) as biomarkers. Rates of progression to end-stage-renal disease are variable among patients. In this study we have examined the GFR decline in newly diagnosed T2DM.

Methods: A cohort of 410 patients with newly diagnosed T2DM and with at least four serum creatinine during the follow-up period were recruited. A linear model was used to calculate the decline in eGFR. A multivariable logistic model was used to identify independent predictors of rapid eGFR decline.

Results: Average follow-up was 12.4 years. The eGFR change was -0.80 ± 2.23 ml/min/1.73 m per year. Patients were arbitrarily stratified into rapid decliners (≤-3.0 ml/min/1.73 m per year), moderate decliners (-2.9/-1 ml/min/1.73 m per year) and slow/no decliners (>-1.0 ml/min/1.73 m per year). Subjects in the 3 categories were 11.4%, 27.3%, and 61.3%, respectively. Albuminuria was the stronger predictor of rapid eGFR decline.

Conclusions: A rapid decline in eGFR occurs in approximately 1 out of 10 newly diagnosed subjects. This rapid decline can be predicted by widely accessible clinical features, such as albuminuria. Identification of rapid decliners may help to reduce progression toward advanced stages of nephropathy.
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http://dx.doi.org/10.1016/j.diabres.2021.108778DOI Listing
May 2021

Prenatal Stress Impairs Spinal Cord Oligodendrocyte Maturation via BDNF Signaling in the Experimental Autoimmune Encephalomyelitis Model of Multiple Sclerosis.

Cell Mol Neurobiol 2020 Dec 1. Epub 2020 Dec 1.

Department of Medical Biotechnology and Translational Medicine, University of Milan, via Vanvitelli 32, 20129, Milan, Italy.

One of the most substantial and established environmental risk factors for neurological and psychiatric disorders is stress exposure, whose detrimental consequences hinge on several variables including time. In this regard the gestational period is known to present an intrinsic vulnerability to environmental insults and thus stressful events during pregnancy can lead to severe consequences on the offspring's brain development with long-term repercussions throughout adulthood. On this basis, we investigated the long-lasting impact of prenatal stress exposure on the susceptibility to the experimental autoimmune encephalomyelitis (EAE), a well-established murine model of multiple sclerosis. Although stress is considered a triggering factor for this chronic, progressive, autoimmune disease, little is known about the underlying mechanisms. To this end, EAE was induced by immunization with MOG35-55/CFA and pertussis toxin administration in adult female C57BL/6 mice born from control or stressed dams exposed to restraint stress during the last days of gestation. Our results demonstrate that gestational stress induces a marked increase in the severity of EAE symptoms in adulthood. Further, we highlight an altered maturation of oligodendrocytes in the spinal cord of prenatally stressed EAE mice, as indicated by the higher levels of GPR17, a marker of immature oligodendrocyte precursor cells. These behavioral and molecular alterations are paralleled by changes in the expression and signaling of the neurotrophin BDNF, an important mediator of neural plasticity that may contribute to stress-induced impaired remyelination. Since several already marketed drugs are able to modulate BDNF levels, these results pave the way to the possibility of repositioning these drugs in multiple sclerosis.
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http://dx.doi.org/10.1007/s10571-020-01014-xDOI Listing
December 2020

Morphology, Surface Structure and Water Adsorption Properties of TiO Nanoparticles: A Comparison of Different Commercial Samples.

Molecules 2020 Oct 10;25(20). Epub 2020 Oct 10.

Department of Chemistry and NIS Centre, University of Torino, via Giuria 7, 10125 Torino, Italy.

Water is a molecule always present in the reaction environment in photocatalytic and biomedical applications of TiO and a better understanding of its interaction with the surface of TiO nanoparticles is crucial to develop materials with improved performance. In this contribution, we first studied the nature and the surface structure of the exposed facets of three commercial TiO samples (i.e., TiO P25, SX001, and PC105) by electron microscopy and IR spectroscopy of adsorbed CO. The morphological information was then correlated with the water adsorption properties, investigated at the molecular level, moving from multilayers of adsorbed HO to the monolayer, combining medium- and near-IR spectroscopies. Finally, we assessed in a quantitative way the surface hydration state at different water equilibrium pressures by microgravimetric measurements.
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http://dx.doi.org/10.3390/molecules25204605DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7587218PMC
October 2020
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