974 research outputs found
Duration of gluten exposure in adult coeliac disease does not correlate with the risk for autoimmune disorders
A multidisciplinary approach to grapevine zoning using GIS technology: An example of thermal data elaboration
Research NoteIn this study we suggest a multidisciplinary approach to zoning based on G.I.S. technology. An example of thermal data elaboration (air temperature) combined with the information derived from the heat requirements of 22 varieties is presented, based on an experiment conducted in an area of the province of Benevento (Campania region, southern Italy). The method combines thermal informations with the Amerine-Winkler bioclimatic index, to obtain a subdivision of the considered territory into five areas, according their thermal suitability. Through the model it was possible to create a map of the optimum thermal suitability of the considered varieties in the various zones of the studied territory.
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Phasor Measurement Units Optimal Placement and Performance Limits for Fault Localization
In this paper, the performance limits of faults localization are investigated using synchrophasor data. The focus is on a non-trivial operating regime where the number of Phasor Measurement Unit (PMU) sensors available is insufficient to have full observability of the grid state. Proposed analysis uses the Kullback Leibler (KL) divergence between the distributions corresponding to different fault location hypotheses associated with the observation model. This analysis shows that the most likely locations are concentrated in clusters of buses more tightly connected to the actual fault site akin to graph communities. Consequently, a PMU placement strategy is derived that achieves a near-optimal resolution for localizing faults for a given number of sensors. The problem is also analyzed from the perspective of sampling a graph signal, and how the placement of the PMUs i.e. the spatial sampling pattern and the topological characteristic of the grid affect the ability to successfully localize faults. To highlight the superior performance of presented fault localization and placement algorithms, the proposed strategy is applied to a modified IEEE 34, IEEE-123 bus test cases and to data from a real distribution grid. Additionally, the detection of cyber-physical attacks is also examined where PMU data and relevant Supervisory Control and Data Acquisition (SCADA) network traffic information are compared to determine if a network breach has affected the integrity of the system information and/or operations
Transseptal or retrograde approach for transcatheter ablation of left sided accessory pathways: a systematic review and meta-analysis
Dead-time impact on the harmonic distortion and conversion efficiency in a three-phase five-level Cascaded H-Bridge inverter: mathematical formulation and experimental analysis
To avoid leg short-circuit in inverters, dead time must be introduced on leg gate signals. Dead time affects the inverter output voltage fundamental harmonic amplitude, voltage harmonic distortion and inverter efficiency by introducing additional voltage drops. In this regard, dead time effects have been widely investigated for traditional two-level three-phase voltage source inverters in the literature but not extensively for multilevel topology structures. This paper provides a detailed analysis of dead time impact on the harmonic distortion and efficiency of Cascaded H-Bridges Multilevel Inverters (CHBMIs). For this purpose, a general mathematical formulation to determine voltage drop due to dead time effects, also taking into account the adopted Multicarrier PWM strategy, has been provided and experimentally validated for a five-level three-phase CHBMI structure. As a comparison tool between expected and ideal inverter output voltage, the percentage voltage error e% is introduced. In most of the cases, e% is lower than 5%, and it starts increasing for very low amplitude modulation index or for specific working points where nonlinearities occur. Furthermore, several experimental investigations have been carried out to evaluate the CHBMI performance in terms of harmonic distortion and efficiency by changing, the values of dead time, modulation index and switching frequency for ten different multi-carried PWM strategies. Experimental results confirm the strong dependency between the dead time impact on the converter performance and the adopted Multi Carrier-PWM (MC-PWM) strategy: as a way of example, converter efficiency can be reduced from 80% to 60% when dead time is increased from 0.5 μs to 1.5 μs and Phase Shifted-PWM (PS-PWM) is adopted
Functionalized nanoporous gold as a new biosensor platform for ultra-low quantitative detection of human serum albumin
Allelic Variants of HLA-C Upstream Region, PSORS1C3, MICA, TNFA and Genes Involved in Epidermal Homeostasis and Barrier Function Influence the Clinical Response to Anti-IL-12/IL-23 Treatment of Patients with Psoriasis
Several biologic therapies have been developed to treat moderate-to-severe psoriasis, with patients exhibiting different clinical benefits, possibly due to the heterogeneity of pathogenic processes underlying their conditions. Ustekinumab targets the IL-12/IL-23-p40 subunit and inhibits type-1 and type-17 T-cell responses. Although ustekinumab is effective as both short- and long-term treatment, therapeutic response varies considerably among patients. Ustekinumab biosimilars will be commercialized in the very next future, likely broadening the use of this drug in the treatment of psoriasis patients. Our pharmacogenomic study evaluated the influence of 417 single-nucleotide polymorphisms (SNPs) in psoriasis-risk alleles on the clinical response to ustekinumab in a cohort of 152 patients affected by moderate-to-severe plaque-type psoriasis. Differences in SNP pattern characterizing HLA-Cw6(+) or HLA-Cw6(-) patients, showing high or low responses to ustekinumab, were also analysed. We identified twelve SNPs in HLA-C upstream region (rs12189871, rs4406273, rs9348862 and rs9368670), PSORS1C3 (rs1265181), MICA (rs2523497), LCE3A-B intergenic region (rs12030223, rs6701730), CDSN (rs1042127, rs4713436), CCHCR1 (rs2073719) and in TNFA (rs1800610) genes associated with excellent response to ustekinumab. We also found that HLA-Cw6(+) and HLA-Cw6(-) patients carried out distinct patterns of SNPs associated with different clinical responses. The assessment of HLA-C alleles, together with other genetic variants, could be helpful for defining patients who better benefit from anti-IL-12/IL-23 therapy
Transforming growth factor β1 T29C gene polymorphism and hypertension: Relationship with cardiovascular and renal damage
Distribution of T29C TGFβ1 gene polymorphism was analysed in 260 hypertensive and 134 normotensive subjects. Circulating TGFβ1 and procollagen type III levels, microalbuminuria, left ventricular geometry and function were evaluated in all the hypertensives subgrouped according to T29C TGFβ1 gene polymorphism. Circulating TGFβ1 by ELISA technique, procollagen type III by a specific radioimmunoassay, microalbuminuria by radioimmunoassay, left ventricular geometry and function by echocardiography were determined. All groups were comparable for gender, age and sex. Regarding T29C TGFβ1 gene polymorphism, prevalence of TC or CC genotypes was significantly (p < 0.05) higher in hypertensives than normotensives. TC and CC hypertensives were characterized by a higher prevalence of subjects with microalbuminuria (p < 0.001 TC vs TT; p < 0.05 CC vs TT), left ventricular hypertrophy (p < 0.01 TC and CC vs TT), and by increased levels of procollagen type III (p < 0.05 TC and CC vs TT). TC hypertensives were also characterized by a significant increase (p < 0.05) of LVM and LVM/h2.7 and of urinary albumin excretion (p < 0.05) values than those detectable in TT hypertensives. Our data suggest that T29C TGFβ1 gene polymorphism was associated to clinical characteristics suitable to recognize hypertensives with a higher severity of hypertension
Latent burnout profiles in a sample of frontline healthcare professionals after the peak of the Italian COVID-19 pandemic
Background: In Italy since February 2020, the unexpected massive afflux of COVID-19 patients exposed healthcare professionals to high work-related stress, high time pressure and increased the risk of being infected. This is the first study that aimed to investigate the psychological impact of COVID-pandemic at the end of the peak, by identifying latent burnout profiles in a sample of front-line healthcare professionals that worked in Italy during the peak of the pandemic. Methods: A total of 589 subjects filled in an online ad-hoc questionnaire and the Italian version of Maslach Burnout Inventory - Human Services Survey. Results: A higher presence of burnout profile in healthcare professionals who worked in frontline during the peak of the COVID-19 pandemic was highlighted. Furthermore, those professionals showed significantly higher perceived stress levels, increase of worries, and sleep problems, they were more likely to underline the importance of team spirit and to consider asking for psychological support. A multiple regression analysis revealed that age, managing COVID-19 patients, perceived stress levels, adequacy of training, and considering to ask for psychological support significantly predicted latent burnout profiles. Moreover, perceived stress levels mediate the relationship between those profiles and managing COVID-19 patients. Conclusions: These findings highlight how stressful and damaging the pandemic has been, especially for people directly involved in the care of patients tested positive for COVID-19. Furthermore, it provides evidence for the importance of investing in wellness for healthcare professionals, in order to avoid shortage due to burnout and to guarantee optimal standards of care to all patient
Switching Frequency Effects on the Efficiency and Harmonic Distortion in a Three-Phase Five-Level CHBMI Prototype with Multicarrier PWM Schemes: Experimental Analysis
The current climatic scenario requires the use of innovative solutions to increase the production of electricity from renewable energy sources. Multilevel Power Inverters are a promising solution to improve the penetration of renewable energy sources into the electrical grid. Moreover, the performance of MPIs is a function of the modulation strategy employed and of its features (modulation index and switching frequency). This paper presents an extended and experimental analysis of three-phase five-level Cascaded H-Bridges Multilevel Inverter performance in terms of efficiency and harmonic content considering several MC PWM modulation strategies. In detail, the CHBMI performance is analyzed by varying the modulation index and the switching frequency. For control purposes, the NI System On Module sbRIO-9651 control board, a dedicated FPGA-based control board for power electronics and drive applications programmable in the LabVIEW environment, is used. The paper describes the modulation strategies implementation, the test bench set-up, and the experimental investigations carried out. The results obtained in terms of Total Harmonic Distorsion (THD) and efficiency are analyzed, compared, and discussed
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