1,131 research outputs found
The Role of Biomarkers, Metabolomics, and COVID-19 in Venous Thromboembolism—A Review of Literature
In recent years, the field of venous thromboembolism has undergone numerous innovations, starting from the recent discoveries on the role of biomarkers, passing through the role of metabolomics in expanding our knowledge on pathogenic mechanisms, which have opened up new therapeutic targets. A variety of studies have contributed to characterizing the metabolic phenotype that occurs in venous thromboembolism, identifying numerous pathways that are altered in this setting. Among these pathways are the metabolism of carnitine, tryptophan, purine, and fatty acids. Furthermore, new evidence has emerged with the recent COVID-19 pandemic. Hypercoagulability phenomena induced by this viral infection appear to be related to altered von Willebrand factor activity, alteration of the renin-angiotensin-aldosterone system, and dysregulation of both innate and adaptive immunity. This is the first literature review that brings together the most recent evidence regarding biomarkers, metabolomics, and COVID-19 in the field of venous thromboembolism, while also mentioning current therapeutic protocols
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
Treatability of digested piggery/poultry manure by anammox bacteria
The liquid fraction of digested material is rich in ammonium and may require nitrogen removal. The aim of this research was to evaluate the applicability of the anammox process for the biological N removal from a supernatant coming from the anaerobic digestion of a mixture of piggery manure, poultry manure, and of agro-wastes. The supernatant was pre-treated in a partial nitritation pilot-scale reactor located at the farm. A batch procedure for testing the short term effect of high-strength wastewaters on anammox activity is presented. The anammox process was successfully applied for the first time to undiluted digestate, and the average N removal efficiency achieved during 350 days of experimentation in a SBR lab-scale reactor was 91%
A Novel Multi-Objective Finite Control Set Model Predictive Control for IPMSM drive fed by a Five-Level Cascaded H-Bridge Inverter
In this work, a novel multi-objective voltage-vector-based finite control set model predictive control for a permanent magnet synchronous machine drive fed by a three-phase five-level cascaded H-bridge multilevel inverter is proposed. This algorithm aims to overcome the main issues relative to model predictive control implementation detected in the scientific literature for electric drives fed by cascaded H-bridge multilevel inverters. In detail, the goals are the minimization of computational cost by reducing the number of required predictions, the minimization of the switching devices state transitions, i.e. the switching losses minimization, and the common mode voltage reduction. These goals are fulfilled through an offline optimization process, thus, no additional terms and weighting factors to be tuned are required for the cost function. Experimental validations are presented to prove the effectiveness of the proposed approach. In detail, an accurate electric drive performance comparison, both in steady state and dynamic working conditions, is carried out when the proposed voltage-vector-based model predictive control and the cell-by-cell-based model predictive control are adopted. As comparison tools, current and voltage total harmonic distortion, apparent switching frequency, common mode voltage amplitude, and torque ripple are adopted
Optimized Finite Control Set Model Predictive Control for a Three-Phase Five-Level Cascaded H-Bridge Multilevel Inverter fed Interior Permanent Magnet Synchronous Machine With On-Line Candidate Switching State Selection
Model predictive control is a novel control strategy that is attracting the scientific community due to the several advantages it offers, such as the ability to consider system nonlinearities, the possibility to synthesize a control for a MIMO system instead of multiple SISO, and so on. Control feasibility, due to the very high computational cost required to solve the optimal control problem, is a challenge. By considering electric drives fed by multilevel inverters, the control design is more challenging due to the increased number of available output voltage vectors. In this work, a simple algorithm for the voltage candidate reduction is presented: it allows for reducing the control computational cost, minimizing the switching losses, and minimizing dv/dt on phase voltage waveforms
Comparison between Voltage Oriented Control and Synchronous Power Control for Grid-Connected Inverter Applications
With the rising of renewable power generation, there are new challenges to be addressed in order to maintain the electrical system operation stability. So, in literature, new grid-connected inverter control techniques have been studied. This paper focuses on a comparison between a grid-following control technique, called Voltage Oriented Control and a grid-forming control technique, called Synchronous Power Control, to underline the advantages offered by the latter. Through a simulation analysis in Matlab/Simulink environment, the benefits and drawbacks of these control approaches have been analyzed and discussed
Heart involvement in Rheumatoid Arthritis: Systematic review and meta-analysis.
OBJECTIVE:
The aim of our study was to conduct a systematic review with meta-analysis of the current case-control studies about the valvular and pericardial involvement in patients with Rheumatoid Arthritis (RA), asymptomatic for cardiovascular diseases.
METHODS:
Case-control studies were identified by searching PubMed (1975-2010) and the Cochrane Central Register of Controlled Trials (CENTRAL) (1975-2010). Participants were adult patients with RA asymptomatic for cardiovascular diseases, and the outcome measure was the presence of cardiac involvement.
RESULTS:
Quantitative synthesis included 10 relevant studies out of 2326 bibliographic citations that had been found. RA resulted significantly associated to pericardial effusion (OR 10.7; 95% CI 5.0-23.0), valvular nodules (OR 12.5; 95% CI 2.8-55.4), tricuspidal valve insufficiency (OR 5.3; 95% CI 2.4-11.6), aortic valve stenosis (OR 5.2; 95% CI 1.1-24.1), mitral valve insufficiency (OR 3.4; 95% CI 1.7-6.7), aortic valve insufficiency (OR 1.7; 95% CI 1.0-2.7), combined valvular alterations (OR 4.3; 95% CI 2.3-8.0), mitral valve thickening and/or calcification (OR 5.0; 95% CI 2.0-12.7), aortic valve thickening and/or calcification (OR 4.4; 95% CI 1.1-17.4), valvular thickening and/or calcification (OR 4.8; 95% CI 2.2-10.5), and mitral valve prolapse (OR 2.2; 95% CI 1.2-4.0).
CONCLUSIONS:
Our systematic review pointed out the strength and the grade of both pericardial and cardiac valvular involvement in RA patients. Our findings underscore the importance of an echocardiographic assessment at least in clinical research when RA patients are involved. Moreover, further research is needed to understand the possible relationship of our findings and the increased cardiovascular mortality
Effects of moderate Sicilian red wine consumption on inflammatory biomarkers of atherosclerosis.
Objective: The aim of the study is to evaluate the effect of moderate Sicilian red wine consumption on cardiovascular risk factors and, in particular, on some inflammatory biomarkers.
Methods: A total of 48 subjects of both sexes who were nondrinkers or rare drinkers of moderate red wine were selected randomly subdivided into two groups assigned to receive with a crossover design a Sicilian red wine (Nero d\u2019Avola or Torrepalino) during meals: Group A (n 24), in whom the diet was supplemented for 4 weeks with 250 ml/day of red followed by 4 weeks when they returned to their usual wine intake; and Group B (n 24), in whom the usual wine intake maintained for 4 weeks, followed by 4 weeks when the diet was supplemented with 250 ml/day of red wine. The following values measured in all tests: blood glucose, total and HDL-cholesterol and triglycerides, LDL-cholesterol, LDL/HDL apolipoproteins A1 and B, Lp(a), plasma C-reactive protein, TGFb1, D-Dimer, Factor VII , PAI Ag, t-PA Ag, fibrinogen, oxidized LDL Ab, total plasma antioxidant capacity.
Results: At the end of the red wine intake period, LDL/HDL, fibrinogen, factor VII, plasma C-reactive protein and oxidized Ab were significantly decreased, while HDL-C, Apo A1,TGFb1, t-PA, PAI and total plasma antioxidant capacity were significantly increased.
Conclusions: Our results show a positive effect of two Sicilian red wines on many risk factors and on some inflammatory biomarkers, suggesting that a moderate consumption of red wine in the adult population is a positive component of Mediterranean diet
A General Analytical Formulation for LCL Filter Design for Grid-Connected PWM-Driven Cascaded H-Bridge Inverters
This paper proposes a general analytical formulation for LCL filter design for grid-connected PWM-driven cascaded Hbridge inverters. The novelty of this work deals with providing some easy-of-use analytical expressions that allow for properly sizing the filter inductances and capacitance values considering the number of voltage levels, the DC-link voltage, the adopted multicarrier pulse width modulation strategy, and the switching frequency. Although multilevel inverters performance strongly depends on the adopted modulation strategy and switching frequency, a general mathematical formulation that allows for properly sizing the LCL filter by considering such parameters simultaneously is currently missing. The proposed approach is generalized for the most adopted multicarrier pulse width modulation strategies. To validate the proposed approach, an extended investigation analysis is performed by hardware-in-the-loop real-time tests. According to international standards EN50160 and IEEE Std 1547- 2018, the voltage total harmonic distortion and current total rated distortion are adopted to evaluate the LCL filter performance. Tests are carried out in several working conditions, defined in terms of provided apparent power and power factor values. Finally, the proposed analytical formulation is adopted to formulate an optimized LCL filter design algorithm that allows for matching the standard requirements without oversizing the filter parameters
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