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Background: The ideal timing for tracheostomy in critically ill patients is still debated. This systematic review and meta-analysis examined whether early tracheostomy improves clinical outcomes compared to late tracheostomy or prolonged intubation in critically ill patients on mechanical ventilation. Methods: We conducted a comprehensive search of randomized controlled trials (RCTs) assessing the risk of clinical outcomes in intensive care unit (ICU) patients who underwent early (within 7–10 days of intubation) versus late tracheostomy or prolonged intubation. Databases searched included PubMed, Embase, and the Cochrane Library up to June 2023. The primary outcome evaluated was mortality, while secondary outcomes included the incidence of ventilator-associated pneumonia (VAP), ICU length of stay, and duration of mechanical ventilation. No language restriction was applied. Eligible studies were RCTs comparing early to late tracheostomy or prolonged intubation in critically ill patients that reported on mortality. The risk of bias was evaluated using the Cochrane Risk of Bias Tool for RCTs, and evidence certainty was assessed via the GRADE approach. Results: This systematic review and meta-analysis included 19 RCTs, covering 3586 critically ill patients. Early tracheostomy modestly decreased mortality compared to the control (RR −0.1511 [95% CI: −0.2951 to −0.0070], p = 0.0398). It also reduced ICU length of stay (SMD −0.6237 [95% CI: −0.9526 to −0.2948], p = 0.0002) and the duration of mechanical ventilation compared to late tracheostomy (SMD −0.3887 [95% CI: −0.7726 to −0.0048], p = 0.0472). However, early tracheostomy did not significantly reduce the duration of mechanical ventilation compared to prolonged intubation (SMD −0.1192 [95% CI: −0.2986 to 0.0601], p = 0.1927) or affect VAP incidence (RR −0.0986 [95% CI: −0.2272 to 0.0299], p = 0.1327). Trial sequential analysis (TSA) for each outcome indicated that additional trials are needed for conclusive evidence. Conclusions: Early tracheostomy appears to offer some benefits across all considered clinical outcomes when compared to late tracheostomy and prolonged intubation.

This paper describes the design and characterisation of a novel hybrid pneumatic rotational actuator that aims to overcome the limitations of both rigid and soft actuators while combining their advantages; indeed, the designed actuator consists of a soft air chamber having an auxetic structure constrained between two rigid frames connected by a soft hinge joint inspired by the musculoskeletal structure of a lobster leg. The main goal is to integrate the advantages of soft actuation, such as inherent compliance and safe human–robot interaction, with those of rigid components, i.e., the robustness and structural stability limiting the ineffective expansion of the soft counterpart of the actuator. The air chamber and its auxetic structure are capable of leveraging the hyper-elastic properties of the soft fabrication material, thereby optimising the response and extending the operational range of the rotational actuator. Each component of the hybrid actuator is fabricated using a 3D-printing method based on Fused Deposition Modeling technology; the soft components are made of thermoplastic polyurethane, and the rigid components are made of polylactic acid. The design phases were followed by some experimental tests to characterise the hybrid actuation by reproducing the typical operating conditions of the actuator itself. In particular, the actuator response in unconstrained expansion and isometric and isobaric conditions has been evaluated. The experimental results show linearity, good repeatability, and sensitivity of the actuator response vs. pneumatic pressure input, other than a small percentage hysteresis, which is ten times less than that observed in commercial soft pneumatic actuators.

This study reports the determination of DNOC in the baits and gastric contents of poisoned dogs and wild canids collected in the Abruzzo region between 2014 and 2022. A total of 663 samples of the baits and carcasses of domestic and wild animals were analyzed for the determination of DNOC through GC-MS. DNOC was found to be present in 58 cases from 663 analyzed samples, with 49 poison baits and nine gastric content samples from dogs and red foxes. This study confirms for the first time that the banned pesticide DNOC still poisons both domestic and wild animals in the Abruzzo region. It should be considered that this study was carried out on a population of animals from a regional geographical area, and more detailed country-wide studies need to be carried out to obtain the incidence of poisoning from this herbicide in Italy. Furthermore, these findings emphasize the importance of considering this chemical in differential diagnosis during toxicological investigations of animal poisoning.

Coxiella burnetii is the causative agent of Q fever. The main reservoirs for this bacterium, which can lead to human infection, in our region are typically cattle, goats, and sheep. In animals, C. burnetii infection is often detected due to reproductive problems. European Member States are required to report confirmed cases annually, but the lack of uniform reporting methods makes the data rather inconsistent. The Istituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise is involved in official controls to identify the causes of abortions, monitor suspected or positive herds, evaluate suspected infections in pets and humans, monitor the spread in wildlife, etc. In this paper, we summarize the presence of C. burnetii over the last five years (2019–2023). Additionally, a detailed overview of C. burnetii infection in wild and domestic animals is provided. Five hundred sixty animals—including cattle; goats; sheep; wild animals, such as deer, boars, wolves, roe deer, owls, and otters; buffalo; dogs; horses; cats; and a donkey—and six human samples were tested by real-time PCR on the transposase gene IS1111 to detect C. burnetii. The MST profile was identified in some of the samples. Outbreaks of C. burnetii occurred in four herds. In one of them, it was possible to follow the outbreak from inception to eradication by evaluating the effect of vaccination on real-time PCR Ct values. A total of 116 animals tested positive for C. burnetii, including 73 goats, 42 sheep, and one bovine. None of the other samples tested positive. The strains for which the ST was performed were identified as ST79, a strain that has been present in the area for more than ten years. The effect of vaccination on the reduction of positive samples and the variation of real-time PCR Ct values was evaluated in strict correlation.

The automotive industry is experiencing radical changes under the pressure of institutions that are increasingly reducing the limits on CO2 and pollutant emissions from road vehicles powered by internal combustion engines (ICEs). A way to decarbonize the transport sector without disrupting current automotive production is the adoption of alternative fuels for internal combustion engines (ICEs). Hydrogen is very attractive, thanks to the zero-carbon content and very high laminar flame speed, allowing for extending the lean burn limit. Other alternative fuels are methanol and ethanol. This work deals with the conversion of a small-sized passenger car powered by a three-cylinder spark ignition (SI) engine for the use of alternative fuels. In particular, the spark timing has been optimized to improve the fuel economy under every operating condition. The optimization procedure is based on the MATLAB/Simulink® R2024a-GT-Power co-simulation analysis and minimizes the fuel consumption by varying the spark timing independently for each cylinder. In particular, at full load, the algorithm reduces the spark timing only for the cylinder in which knock is detected, reducing fuel consumption by about 2% compared to the base calibration. This approach will be adopted in future activities to understand how the use of alternative fuels affects the ignition control strategy.

Background: Training is required to achieve proficiency in airway management. Simulators are of utmost importance not only for the purpose of training novices, but also for evaluating newer airway devices and techniques. Growing evidence supports inadequate anatomic airway reproduction in adult and pediatric manikins. Methods: We conducted an observational study comparing 17 radiological anatomic airway measurements obtained via the computed tomography of three commercially available manikins with the same measurements obtained from a population of newborns/infant (range: 0–3 months) undergoing magnetic resonance imaging for diagnostic purposes. According to the reference (mean and standard deviation (SD) of the pediatric population), each manikin measurement was defined as adequate, partially adequate or inadequate (difference between means: ≤±1, 1.0–1.96 or >1.96 SD, respectively). The primary outcome was the number of measurements with an adequate reproduction of airways. Results: We included 27 pediatric patients (21 ± 19 days, 48% males, 46.6 ± 3.5 cm, 2.7 ± 0.5 Kg and 12.6 ± 2.9 kg/m2). All manikins had n = 11/17 measurements with inadequate airway anatomic reproduction. The three measurements with more adequate reproduction were the height of the soft palate, retropalatal airspace volume and tongue volume (adequate in two manikins, and partially adequate in the remaining one). Conclusions: In three manikins commonly used for training in pediatric airways, static dimensions do not seem anatomically correct in relation to those of pediatric patients. Such inaccuracies may introduce biases in airway device development as well as in training.

The pursuit of sustainable and environmentally friendly transportation has led to the exploration of alternative fuel sources, among which hydrogen stands out prominently. This work delves into the potential of hydrogen fuel for internal combustion engines (ICEs), emphasizing its capacity to ensure the required performance levels while concurrently enhancing overall efficiency. The integration of a mild hybrid powertrain in a small size passenger car was considered for obtaining a twofold advantage: mitigating power loss due to low volumetric efficiency and increasing fuel economy. A comprehensive approach combining 0D/1D modeling simulations and experimental validations was employed on a gasoline-powered small size ICE, considering its conversion to hydrogen, and mild hybridization. Vehicle simulations were performed in AVL Cruise M and validated against experimental data. Various electric motors were scrutinized for a small size battery pack typical of mild hybrid vehicles. Furthermore, the paper assesses the potential range achievable with the hydrogen-powered hybrid vehicle and compares it with the range reported by the manufacturer for the original gasoline and pure electric version. In terms of global results, these modifications were found to successfully improve efficiency compared to baseline gasoline and hydrogen fueling. Additionally, performance gains were achieved, surpassing the capabilities of the original gasoline vehicle despite its intrinsic volumetric efficiency limitations when using hydrogen. Along with the conversion to hydrogen and thus zero-carbon tail-pipe emissions, incorporating a Start/Stop system, and the integration of mild hybrid technology with energy recuperation during braking, overall efficiency was enhanced by up to 30% during urban use. Furthermore, the hybridization implemented in the H2 version allows an autonomy comparable to that of the electric vehicle but with evident shorter refilling times. Specific aspects of the 48 V battery management are also scrutinized.

Recent advancements in the automotive field have significantly increased the level of complexity and connectivity of modern vehicles. In this context, the topic of cybersecurity becomes extremely relevant, as a successful attack can have an impact in terms of safety on the car navigation, potentially leading to harmful behavior. Risk assessment is typically performed using discrete input and output scales, which can often lead to an identical output in terms of risk evaluation despite the inputs presenting non-negligible differences. This work presents a novel fuzzy-logic-based methodology to assess cybersecurity risks which takes attack feasibility and safety impact as input factors. This technique allows us explicitly model the uncertainty and ambiguousness of input data, which is typical of the risk assessment process, providing an output on a more detailed scale. The fuzzy inference engine is based on a set of control rules expressed in natural language, which is crucial to maintaining the interpretability and traceability of the risk calculation. The proposed framework was applied to a case study extracted from ISO/SAE 21434. The obtained results are in line with the traditional methodology, with the added benefit of also providing the scatter around the calculated value, indicating the risk trend. The proposed method is general and can be applied in the industry independently from the specific case study.

The SI4CARE project is a transnational project which aims to develop both strategy and action plans to improve health and social care in the Adriatic–Ionian region. Starting from a survey of the status quo, each partner has developed some pilots to support the development and monitoring of the policy actions. In particular, partner number three, the Municipality of Miglierina, designed and developed a pilot related to the use of wearable devices for monitoring elderly patients in rural areas. With the collaboration of the complex unity of primary care (UCCP) of the Reventino area, the pilot is based on the use of smart wearable devices to monitor some parameters of older adults after their vaccinations for flu and covid. This paper focused on the design and implementation of the system. It describes its application in the Municipality of Miglierina. Presentation of the results and a discussion of the strengths and weaknesses will be presented, in detail, in future work. Finally, the possibility of extending the experiment to other Adriatic–Ionian regions is addressed.

The use of peat, the standard substrate used for soilless cultivation of horticultural crops, is becoming of increasing concern as peat is a non-renewable resource and its extraction can degrade wetland ecosystems, creating a strong environmental impact. For this reason, the search for organic materials that can totally or partially replace peat has become increasingly important. In this research, three types of composts (C1, C2, C3), derived from cardoon biomass mixed in different volumes with woody and/or fruit wastes, were utilized as the constituents of growing media, at two dilution rates with peat (60:40 and 30:70 v:v), to assess their effect on the growth and quality of baby leaf lettuce in a greenhouse trial. The two cultivars Imperiale and Verde d’Inverno, belonging to the butterhead and romaine lettuce types, respectively, were employed. Plant performance and yield were unaffected or were positively affected by compost-containing growing medium compared to the control. The cultivars responded differently to the growing medium; the Imperiale showed the highest yield with C1 compost at a 60% rate while the Verde d’Inverno with the C2 was at 30%. The total chlorophyll, carotenoids, and ascorbic acid were found higher in the Verde d’Inverno than in the Imperiale variety while the total polyphenols, flavonoids, and antioxidant activity were lower. Also, the content of chlorophylls as well as of antioxidant compounds and antioxidant activity were differently affected by the growing medium, depending on the lettuce cultivar. The results obtained indicate that cultivated cardoon waste-based compost is a promising constituent of the growing media for baby leaf production. The specific varietal response observed should be considered to optimize both yield and product quality.

The characterization of small-size engines requires dedicated rigs that are usually used for loading the power unit. Adding the possibility of motoring the engine is an important advantage that allows more detailed information on operating characteristics. It can be used for obtaining precious data that contribute to the development of more accurate numerical models and subsequent validation. Cost competitiveness is another essential aspect of small-size engines, given that development efforts need to be contained as much as possible. Within this context, the present work developed and tested a setup capable of cranking and motoring a small-size 50 cc spark ignition engine. Two configurations were considered for coupling an electric motor to the power unit: the first through a pulley-belt transmission and the second via a plastic clutch assembly. The main idea was to ensure the capability of motoring the engine up to a rotational velocity of 6000 rpm. Engine load was applied through a 1 kW electric generator connected directly to the crankshaft. The overall setup was designed in the two configurations and a stress–strain analysis was performed. The belt-driven option was found to be more favorable in terms of mechanical component requirements, showing a safety factor of around 4.0, while the plastic clutch assembly involved a more complex design phase and turned out to be more demanding, with a safety factor of around 2.9.

Hydrogen is seen as a prime choice for complete replacement of gasoline so as to achieve zero-emissions energy and mobility. Combining the use of this alternative fuel with a circular economy approach for giving new life to the existing fleet of passenger cars ensures further benefits in terms of cost competitiveness. Transforming spark ignition (SI) engines to H2 power requires relatively minor changes and limited added components. Within this framework, the conversion of a small-size passenger car to hydrogen fueling was evaluated based on 0D/1D simulation. One of the methods to improve efficiency is to apply exhaust gas recirculation (EGR), which also lowers NOx emissions. Therefore, the previous version of the quasi-dimensional model was modified to include EGR and its effects on combustion. A dedicated laminar flame speed model was implemented for the specific properties of hydrogen, and a purpose-built sub-routine was implemented to correctly model the effects of residual gas at the start of combustion. Simulations were performed in several operating points representative of urban and highway driving. One of the main conclusions was that high-pressure recirculation was severely limited by the minimum flow requirements of the compressor. Low-pressure EGR ensured wider applicability and significant improvement of efficiency, especially during partial-load operation specific to urban use. Another benefit of recirculation was that pressure rise rates were predicted to be more contained and closer to the values expected for gasoline fueling. This was possible due to the high tolerance of H2 to the presence of residual gas.

Cationic antimicrobial peptides (CAMPs) are powerful molecules with antimicrobial, antibiofilm and endotoxin-scavenging activities. These properties make CAMPs very attractive drugs in the face of the rapid increase in multidrug-resistant (MDR) pathogens, but they are limited by their susceptibility to proteolytic degradation. An intriguing solution to this issue could be the development of functional mimics of CAMPs with structures that enable the evasion of proteases. Peptoids (N-substituted glycine oligomers) are an important class of peptidomimetics with interesting benefits: easy synthetic access, intrinsic proteolytic stability and promising bioactivities. Here, we report the characterization of P13#1, a 13-residue peptoid specifically designed to mimic cathelicidins, the best-known and most widespread family of CAMPs. P13#1 showed all the biological activities typically associated with cathelicidins: bactericidal activity over a wide spectrum of strains, including several ESKAPE pathogens; the ability to act in combination with different classes of conventional antibiotics; antibiofilm activity against preformed biofilms of Pseudomonas aeruginosa, comparable to that of human cathelicidin LL-37; limited toxicity; and an ability to inhibit LPS-induced proinflammatory effects which is comparable to that of “the last resource” antibiotic colistin. We further studied the interaction of P13#1 with SDS, LPSs and bacterial cells by using a fluorescent version of P13#1. Finally, in a subcutaneous infection mouse model, it showed antimicrobial and anti-inflammatory activities comparable to ampicillin and gentamicin without apparent toxicity. The collected data indicate that P13#1 is an excellent candidate for the formulation of new antimicrobial therapies.

A minimally-invasive manipulator characterized by hyper-redundant kinematics and embedded sensing modules is presented in this work. The bending angles (tilt and pan) of the robot tip are controlled through tendon-driven actuation; the transmission of the actuation forces to the tip is based on a Bowden-cable solution integrating some channels for optical fibers. The viability of the real-time measurement of the feedback control variables, through optoelectronic acquisition, is evaluated for automated bending of the flexible endoscope and trajectory tracking of the tip angles. Indeed, unlike conventional catheters and cannulae adopted in neurosurgery, the proposed robot can extend the actuation and control of snake-like kinematic chains with embedded sensing solutions, enabling real-time measurement, robust and accurate control of curvature, and tip bending of continuum robots for the manipulation of cannulae and microsurgical instruments in neurosurgical procedures. A prototype of the manipulator with a length of 43 mm and a diameter of 5.5 mm has been realized via 3D printing. Moreover, a multiple regression model has been estimated through a novel experimental setup to predict the tip angles from measured outputs of the optoelectronic modules. The sensing and control performance has also been evaluated during tasks involving tip rotations.

Antimicrobial resistance (AMR) has emerged as a global health crisis, necessitating the search for innovative strategies to combat infectious diseases. The unique biodiversity of Italian flora offers a treasure trove of plant species and their associated phytochemicals, which hold immense potential as a solution to address AMR. By investigating the antimicrobial properties of Italian flora and their phytochemical constituents, this study aims to shed light on the potential of phyto-complexes as a valuable resource for developing novel or supportive antimicrobial agents useful for animal production.

Due to increased powertrain efficiency, electrified propulsion has seen significant diffusion in the automotive sector in recent years. Despite the possible reduction in tailpipe CO2 emissions, the advancements in the technology are not sufficient to tackle the challenge of global greenhouse emissions. An additional action could be the use of second life vehicles to drastically reduce the emissions associated with vehicle manufacturing and recycling/disposal. Urban vehicles are the most suitable to be electrified due to the large start-and-stop cycling and the possibility of using regenerative braking. Therefore, this work considered the hypothesis of hybridizing a small size passenger car with parallel and Series technology. The powertrain is designed for an old vehicle suitable for second life use after refurbishment. A numerical model of the propulsion components was built and applied after previous validation in homologation conditions. Several urban cycles representative of European cities were considered. The final hybrid model is compared with two baselines: non-hybrid and pure electric version already lunched in the market by the manufacturer. The findings indicate that used HEV cars could be a viable option for cutting CO2 emissions from city vehicles without reducing their range. In comparison to non-hybrid vehicles, the series can typically reduce CO2 emissions by 41%, compared to the P2’s 32%.

Mathematical models can improve the understanding of physiological systems behaviour, which is a fundamental topic in the bioengineering field. Having a reliable model enables researchers to carry out in silico experiments, which require less time and resources compared to their in vivo and in vitro counterparts. This work’s objective is to capture the characteristics that a nonlinear dynamical mathematical model should exhibit, in order to describe physiological control systems at different scales. The similarities among various negative feedback physiological systems have been investigated and a unique general framework to describe them has been proposed. Within such a framework, both the existence and stability of equilibrium points are investigated. The model here introduced is based on a closed-loop topology, on which the homeostatic process is based. Finally, to validate the model, three paradigmatic examples of physiological control systems are illustrated and discussed: the ultrasensitivity mechanism for achieving homeostasis in biomolecular circuits, the blood glucose regulation, and the neuromuscular reflex arc (also referred to as muscle stretch reflex). The results show that, by a suitable choice of the modelling functions, the dynamic evolution of the systems under study can be described through the proposed general nonlinear model. Furthermore, the analysis of the equilibrium points and dynamics of the above-mentioned systems are consistent with the literature.

Streptococcus equi sub. zooepidemicus (SEZ) is described as a commensal bacterium of several animal species, including humans. Growing evidence supports the potential role of SEZ in the onset and progression of severe clinical manifestations of diseases in horses and other animals. In the present communication, we describe the diagnostic procedure applied to characterize the streptococcal infections caused by a novel SEZ sequence type (ST525) in donkeys raised on a farm in Abruzzo, Italy. The diagnostic process began with anamnesis and anatomopathological analysis, which revealed a severe bacterial suppurative bronchopneumonia associated with systemic vascular damage and haemorrhages. Then, SEZ infection was confirmed by applying an integrative diagnostic strategy that included standard bacterial isolation techniques, analytical tools for bacteria identification (MALDI-TOF MS), and molecular analysis (qPCR). Furthermore, the application of the whole-genome sequencing approach helped us to identify the bacterial strains and the virulence factors involved in animal diseases. The novel SEZ-ST525 was identified in two cases of the disease. This new sequence type was isolated from the lung, liver, and spleen in Case 1, and from retropharyngeal lymph nodes in Case 2. Moreover, the presence of the virulence gene mf2, a virulence factor carried by prophages in Streptococcus pyogenes, was also found for the first time in an SEZ strain. The results of the present study highlight the need to apply an integrated diagnostic approach for the identification and tracking of pathogenic strains of SEZ, shedding new light on the re-evaluation of these bacteria as a causative agent of disease in animals and humans.

Hydrogen is an effective route for achieving zero carbon dioxide emissions, with a contained cost compared to electric powertrains. When considering the conversion of spark ignition (SI) engines to H2 fueling, relatively minor changes are required in terms of added components. This study looks at the possibility of converting a small-size passenger car powered by a turbocharged SI unit. The initial evaluation of range and peak power showed that overall, the concept is feasible and directly comparable to the electric version of the vehicle in terms of powertrain performance. Injection phasing effects and cylinder imbalance were found to be potential issues. Therefore, the present work applied an 0D/1D simulation for investigating the effects of hydrogen fueling with respect to the likelihood of backfire. A range of engine speeds and load settings were scrutinized for evaluating the possibility of achieving the minimal risk of abnormal combustion due to pre-ignition. Ensuring the correct flow was predicted to be essential, especially at high loads and engine speeds. Fuel delivery phasing with respect to valve intake and closing events was also found to be a major factor that influenced not only backfire occurrence but conversion efficiency as well. Interactions with the electronic control unit were also evaluated, and additional requirements compared to standard conversion kits for LPG or CNG fueling were identified.

The dispersion of uranium in the environment can pose a problem for the health of humans and other living organisms. It is therefore important to monitor the bioavailable and hence toxic fraction of uranium in the environment, but no efficient measurement methods exist for this. Our study aims to fill this gap by developing a genetically encoded FRET-based ratiometric uranium biosensor. This biosensor was constructed by grafting two fluorescent proteins to both ends of calmodulin, a protein that binds four calcium ions. By modifying the metal-binding sites and the fluorescent proteins, several versions of the biosensor were generated and characterized in vitro. The best combination results in a biosensor that is affine and selective for uranium compared to metals such as calcium or other environmental compounds (sodium, magnesium, chlorine). It has a good dynamic range and should be robust to environmental conditions. In addition, its detection limit is below the uranium limit concentration in drinking water defined by the World Health Organization. This genetically encoded biosensor is a promising tool to develop a uranium whole-cell biosensor. This would make it possible to monitor the bioavailable fraction of uranium in the environment, even in calcium-rich waters.

Antimicrobial resistance (AMR) is one of the world’s industrialized nations’ biggest issues. It has a significant influence on the ecosystem and negatively affects human health. The overuse of antibiotics in the healthcare and agri-food industries has historically been defined as a leading factor, although the use of antimicrobial-containing personal care products plays a significant role in the spread of AMR. Lotions, creams, shampoos, soaps, shower gels, toothpaste, fragrances, and other items are used for everyday grooming and hygiene. However, in addition to the primary ingredients, additives are included to help preserve the product by lowering its microbial load and provide disinfection properties. These same substances are released into the environment, escaping traditional wastewater treatment methods and remaining in ecosystems where they contact microbial communities and promote the spread of resistance. The study of antimicrobial compounds, which are often solely researched from a toxicological point of view, must be resumed considering the recent discoveries, to highlight their contribution to AMR. Parabens, triclocarban, and triclosan are among the most worrying chemicals. To investigate this issue, more effective models must be chosen. Among them, zebrafish is a crucial study system because it allows for the assessment of both the risks associated with exposure to these substances as well as environmental monitoring. Furthermore, artificial intelligence-based computer systems are useful in simplifying the handling of antibiotic resistance data and speeding up drug discovery processes.

The intake manifold and its components play a key role in the proper formation of air–fuel mixtures suitable for correct engine operation. In this article, starting from the original intake manifold design fitted to an optically accessible spark-ignited engine, a new solution was developed so as to allow the application of high-speed imaging of the fuel jet located between the runner and intake valves (Port Fuel Injection). To compare the two designs in terms of overall engine performance parameters such as volumetric efficiency, 0D/1D simulations were performed in motored conditions. Measurements at different crankshaft speed values were used for calibrating the intake line parameters and providing boundary conditions. Finite Element Analysis (FEM) was performed in SolidWorks to verify the structural strength of the new design when operating in the most critical conditions, i.e., boosted operation. As an overall conclusion, the results show that the new design guarantees a wider range of intake pressure values during the intake stroke, thus expanding the possible operative points. This can be obtained without compromising structural integrity, given that predicted safety factors were well above acceptable limits even for relatively high boost levels.

In the efforts to achieve zero-emission transportation, hydrogen offers a valid choice as a complete replacement of gasoline. Adapting spark ignition (SI) engines to this alternative fuel can be implemented with relatively minor changes and limited investment in added components. The conversion of a small-size passenger car to hydrogen fueling was evaluated initially from the perspective of achievable range and peak power. Overall, the concept was found to be feasible and comparable to the fully electric version of the vehicle. Cylinder imbalance was found to be one of the possible issues compared to gasoline operation. This study looks in more detail at cycle-to-cycle variability (CCV) and how this could influence vehicle dynamics as well as noise–harshness–vibration (NHV). CCV was simulated with a 0D/1D approach in vehicle-relevant engine speed–load conditions. A dedicated laminar flame speed sub-model was implemented so as to include fuel chemistry effects, while CCV was simulated by inducing perturbations in the initial combustion stages and fuel system characteristics as well as variation of air–fuel ratio throughout flame propagation. Significant improvement of stability was predicted with hydrogen, while cylinder imbalance was found to be one of the main sources of variability. Applying algorithms that compensate for the imbalance through individual injection valve regulation may not be enough to mitigate the identified issue, and more extensive changes of control strategies could be required. The start of injection settings may need to be adapted for each operating condition to maximize the effect of H2 combustion stabilization.

Spark ignition (SI) engines are often used as distributed power generation applications. They ensure quick deployment, cost effective electricity, and are a valid choice for back-up power. An essential aspect for small size engines is to improve control margins without increasing the number of sensors. It is not uncommon to employ fixed ignition timing for such power units, with so called wasted spark systems. These feature two spark events per cycle, one during compression and one during the exhaust stroke. On the other hand, ever more complex control systems are applied for this engine category in the search for better efficiency and lower emissions. Control of actuators that is phased with the working cycle could represent a significant advantage in this context. A method previously developed for identifying top dead center (TDC) phasing offline was applied as an algorithm capable of performing the required task while the engine is running. It is based on current measurements in the secondary ignition circuit of systems that feature wasted spark operation. Validation was performed on a 50 cm3 SI unit connected to a 1 kW power generator. Statistical distribution during sequences of 1000 cycles recorded at five different levels of load was used for testing TDC identification capabilities. Results were also compared to evaluations based on engine speed measurements. The overall TDC identification success rate of the proposed algorithm was found to be over 99.8%.

The release of the cardiac troponin T (cTnT) in patients with acute myocardial infarction (AMI) has been analyzed through a methodology based on nonlinear mixed-effects (NME) models. The aim of this work concerns the investigation of any possible relationship between clinical covariates and the dynamics of the release of cTnT to derive more detailed and useful clinical information for the correct treatment of these patients. An ad-hoc mechanistic model describing the biomarker release process after AMI has been devised, assessed, and exploited to evaluate the impact of the available clinical covariates on the cTnT release dynamic. The following approach was tested on a preliminary dataset composed of a small number of potential clinical covariates: employing an unsupervised approach, and despite the limited sample size, dyslipidemia, a known risk factor for cardiovascular disease, was found to be a statistically significant covariate. By increasing the number of covariates considered in the model, and patient cohort, we envisage that this approach may provide an effective means to automatically classify AMI patients and to investigate the role of interactions between clinical covariates and cTnT release.

Several studies performed in humans have demonstrated that the onset of systemic inflammatory response syndrome (SIRS) represents a high risk condition to develop myocardial damage and arrhythmias. Therefore, we also hypothesized cardiac involment for dogs affected by SIRS. To assess this hypothesis, 24 dogs with a diagnosis of SIRS (13 entire males, 7 entire females, and 4 spayed females) with an age ranging from 4 to 11 years (mean 5.6 years) and an average weight of 24 kg (range from 5 to 47 kg) were enrolled. The dogs were divided into two groups according to their prognosis: Survivors (G1) and not survivors (G2), composed by 13 and 11 dogs, respectively. Moreover, healthy dogs were included as the control group (CTR). All the dogs with a history of cardiac or renal disease were excluded. At the inclusion, each patient underwent a physical examination and a complete cell count, and a biochemistry panel (including electrolyte profile) was performed; moreover, the blood cardiac Troponin I (cTnI) was measured. For each clinical variable indicative of SIRS, a score between 0 (absence) and 1 (presence) was applied. Furthermore, an electrocardiographic examination was recorded. Seventeen out of 24 (70.8%) dogs with SIRS showed arrhythmias, of which n. 6 belonged to the G1, while n. 11 belonged to the G2. Most represented findings were sinus tachycardia (7/17; 41.1%), followed by monomorphic premature ventricular beats (6/17; 35.3%), less common were first-degree atrioventricular block (2/17; 11.7%) and sinus bradycardia 1/17; 5.8%). Notably, in G1 dogs, only sinus tachycardia and premature ventricular beats were observed. G2 dogs presented a number of total and banded leukocytes significantly higher than those of G1 (p = 0.002 and 0.049), in the same manner, the clinical score suggestive of SIRS (3 vs. 2.1) was significantly higher in G2 than in G1 dogs (p = 0.01). Moreover, a significantly higher value of cTnI was observed in the G2 group compared to the G1 group (p = 0.006). Data presented here suggested a cardiac involvement in dogs with SIRS, analogously to humans, that may significantly influence the patient’s prognosis.

The present study investigated the macroscopical and histological features of two spontaneous seminomas developed by zebrafish adults. Two wild-type male zebrafish of AB/TU strain aged 2 and 3 years, respectively, developed gross pathological signs consisting of asymmetrical swollen abdomens. In one fish, named fish 1, the testicular alteration is referred to as one testis (the right one), while in fish 2, both testes were altered in their size and shape. No signs of invasion were reported. The histological analysis revealed an extensive differentiation of germ cells in various developmental stages without any oocyte, and both lesions were compatible with spermatocytic and intratubular seminomas. The etiology and the pathogenesis of the reported lesions could be related to an intricate and interconnected network of intrinsic and extrinsic factors, including the housing condition, diet, genetic background, and operator training.

Lean burn spark ignition (SI) engines represent an effective solution for improving fuel economy and reducing exhaust emissions and can be implemented both in conventional and hybrid powertrains. On the other hand, lean operation increases cyclic variability with negative impact on power output, engine efficiency, roughness, and operating stability. Although this phenomenon has been widely investigated, the effects of flow field on the inception and development of flames in direct injection spark ignition (DISI) engines under lean burn conditions is not yet completely understood. In particular, the effect of spark plug geometry and electrode orientation with respect to tumble motion has been minimally investigated. For these reasons, two different spark-plug geometries (i.e., single- and double-ground electrode) and three different orientations (i.e., cross-, counter-, and uni-flow with respect to the direction of tumble motion) were investigated in an optically accessible DISI engine for understanding their influence on the initial phase of combustion. The relative air–fuel ratio (AFRrel) was changed from stoichiometric to lean burn (1.00 to 1.30) for different spark timings around the maximum brake torque setting at fixed engine speed (2000 rpm). An image processing procedure was developed for evaluating the morphological parameters of flame kernels and studying the effects of spark plug design on engine operating stability. With a focus on the correlation between the position where ignition occurs with the subsequent locations of the flame kernel during the first phases of the combustion process, the analysis allowed the gathering of a better understanding of the influence that the electrodes’ geometries and orientation can have on the first stages of combustion development.

This study aimed to evaluate possible abnormalities in electrocardiographic findings, and changes in cardiac troponin I (cTnI) and inflammatory biomarkers (serum amyloid A (SAA) and C-reactive protein (CRP)) after inactivated herpesvirus vaccine administration. Eighteen healthy horses were included. All animals were vaccinated with Pneumoequine® (Merial, France) according to the protocol provided by the manufacturer. They were evaluated 1 day before the first dose of vaccination (D0), and 7 days (D1) and 14 days (D2) afterwards. At D0, D1, and D2, a blood sample was taken for the evaluation of SAA, cTnI, and CRP. An electrocardiographic examination was also performed. The data obtained suggested the possible involvement of the myocardium following vaccination against herpesvirus 1, mostly related to an inflammatory response.

Acarapis woodi is a pathogen affecting honey bees health worldwide. Its prevalence may be underestimated due to the time-consuming traditional method for its diagnosis and the attitude in focusing the attention only onto Varroa destructor. New PCR techniques have allowed for the verification of the presence of A. woodi in 44 samples of honey bees and 11 samples of hive debris collected from 17 apiaries by the veterinary services of the Latium region (Central Italy). Overall, 9.1% of adult honey bee samples (all belonging to one apiary) and 6.3% of hive debris samples (belonging to 6 apiaries) were positive in an end point PCR and presence of the pathogen was confirmed through Sanger sequencing. Results demonstrated the potential underestimation of A. woodi occurrence in Italian apiaries and reported the first detection of A. woodi in hive debris samples.

The study aimed to evaluate the concentration of reactive oxidative metabolites (R-OOHs), the antioxidant barrier (OXY), and the ratio between R-OOHs and OXY (OSi) and thiol groups of plasma compounds (SHp) in in canine monocytic ehrlichiosis. Thirty dogs affected with monocytic ehrlichiosis (canine monocytic ehrlichiosis group—CME group) and ten healthy dogs (control group—CTR group) were evaluated. CME was diagnosed by the presence of clinical signs and the detection of anti-Ehlichia canis antibodies. Oxidative stress parameters of two groups were compared using the Mann–Whitney test. Significance was set at p < 0.05. Spearman rank correlation was performed to analyze oxidative stress, and hematological and biochemical variables in the CME group. All dogs affected with CME showed a wide spectrum of clinical signs such as lethargy, anorexia, fever, weight loss, lymph adenomegaly, splenomegaly, subcutaneous and mucosal petechial and ecchymosis, and vomiting. Anaemia, leukocytosis, thrombocytopenia, hyperglobulinemia, hypoalbuminemia and an increase of blood urea nitrogen and creatinine are also detected. Results showed significantly lower values of SHp in the CME group than in CTR. A statistically significant difference in the number of white blood cells, platelets, and blood urea nitrogen concentration was assayed comparing to the two groups. A negative correlation between SHp and hemoglobin concentration was recorded. These preliminary results may suggest a possible function of oxidative stress in the onset of clinical signs during the course of CME.

This paper presents the mechatronic design of a biorobotic joint with controllable compliance, for innovative applications of “assist-as-needed” robotic rehabilitation mediated by a wearable and soft exoskeleton. The soft actuation of robotic exoskeletons can provide some relevant advantages in terms of controllable compliance, adaptivity and intrinsic safety of the control performance of the robot during the interaction with the patient. Pneumatic Artificial Muscles (PAMs), which belong to the class of soft actuators, can be arranged in antagonistic configuration in order to exploit the variability of their mechanical compliance for the optimal adaptation of the robot performance during therapy. The coupling of an antagonistic configuration of PAMs with a regulation mechanism can achieve, under a customized control strategy, the optimal tuning of the mechanical compliance of the exoskeleton joint over full ranges of actuation pressure and joint rotation. This work presents a novel mechanism, for the optimal regulation of the compliance of the biorobotic joint, which is characterized by a soft and hybrid actuation exploiting the storage/release of the elastic energy by bistable Von Mises elastic trusses. The contribution from elastic Von Mises structure can improve both the mechanical response of the soft pneumatic bellows actuating the regulation mechanism and the intrinsic safety of the whole mechanism. A comprehensive set of design steps is presented here, including the optimization of the geometry of the pneumatic bellows, the fabrication process through 3D printing of the mechanism and some experimental tests devoted to the characterization of the hybrid soft actuation. The experimental tests replicated the main operating conditions of the regulation mechanism; the advantages arising from the bistable hybrid soft actuation were evaluated in terms of static and dynamic performance, e.g., pressure and force transition thresholds of the bistable mechanism, linearity and hysteresis of the actuator response.

The reaction of palladium(II) acetate with acyclic amino acids in acetone/water yields square planar bis-chelated palladium amino acid complexes that exhibit interesting non-covalent interactions. In all cases, complexes were examined by multiple spectroscopic techniques, especially HRMS (high resolution mass spectrometry), IR (infrared spectroscopy), and 1H NMR (nuclear magnetic resonance) spectroscopy. In some cases, suitable crystals for single crystal X-ray diffraction were able to be grown and the molecular structure was obtained. The molecular geometries of the products are discussed. Except for the alanine complex, all complexes incorporate water molecules into the extended lattice and exhibit N-H···O and/or O···(HOH)···O hydrogen bonding interactions. The non-covalent interactions are discussed in terms of the extended lattice structures exhibited by the structures.

SARS-CoV-2 emerged in 2019 as a devastating viral pathogen with no available preventative or treatment to control what led to the current global pandemic. The continued spread of the virus and increasing death toll necessitate the development of effective antiviral treatments to combat this virus. To this end, we evaluated a new class of organometallic complexes as potential antivirals. Our findings demonstrate that two pentamethylcyclopentadienyl (Cp*) rhodium piano stool complexes, Cp*Rh(1,3-dicyclohexylimidazol-2-ylidene)Cl2 (complex 2) and Cp*Rh(dipivaloylmethanato)Cl (complex 4), have direct virucidal activity against SARS-CoV-2. Subsequent in vitro testing suggests that complex 4 is the more stable and effective complex and demonstrates that both 2 and 4 have low toxicity in Vero E6 and Calu-3 cells. The results presented here highlight the potential application of organometallic complexes as antivirals and support further investigation into their activity.

The objectives of this research were, first, to determine the concentrations of certain heavy metals in the edible tissue of wild brown trout (Salmo trutta trutta) from two different rivers located in the Abruzzi region (Italy), and then, to investigate the levels of variation in vitellogenin (VTG) associated with the presence of metalloestrogens. VTG is an effective indicator for endocrine disturbance, and an increase in the vitellogenin levels in male fish is widely employed as a biomarker of estrogenic contamination in the aquatic environment. The muscles of the trout were analyzed for As, Cd, Co, Cr, Ni, Pb, Al, and Zn using an inductively coupled plasma-mass spectrometer (ICP-MS), and Hg was measured using a direct mercury analyzer (DMA-80). The calculated values of the condition factor confirmed a healthy status for this species, indicating that the aquatic habit in both rivers is suitable for brown trout life. No significant difference in the concentrations of each metal were reported between the trout from the two rivers, and no significant difference for VTG levels were found between male and female fish. It is interesting to note the high concentrations of Al/Zn, while the Pb, Cd, and Hg concentrations in all of the samples were lower than those established by the European Commission.

Bell pepper is the common name of the berry obtained from some varieties of the Capsicum annuum species. This agro-food is appreciated all over the world and represents one of the key ingredients of several traditional dishes. It is used as a fresh product, or dried and ground as a seasoning (e.g., paprika). Specific varieties of sweet pepper present organoleptic peculiarities and they have been awarded by quality marks as a further confirmation of their unicity (e.g., Piment d’Espelette, Pimiento de Herbón, Peperone di Senise). Due to the market value of this aliment, it can be subjected to frauds, such as adulterations and sophistication. The present study lays on these considerations and aims at developing a spectroscopy-based approach for authenticating Senise bell pepper and for detecting its adulteration with common paprika. In order to achieve this goal, 60 pure samples of bell pepper from Senise were analyzed by mid- and near-infrared spectroscopies. Then, in order to mimic the adulteration, 40 mixtures of Senise bell pepper and paprika were prepared and analyzed (by the same spectroscopic techniques). Eventually, two different multi-block classification approaches (sequential and orthogonalized partial least squares linear discriminant analysis and sequential and orthogonalized covariance selection linear discriminant analysis) were used to discriminate between pure and adulterated Senise bell pepper samples. Both proposed procedures achieved extremely successful results in external validation, correctly classifying all the (thirty-five) test samples, indicating that both approaches represent a winning solution for the investigated classification problem.

Diatoms are among the dominant phytoplankters in marine and freshwater habitats, and important biomarkers of water quality, making their identification and classification one of the current challenges for environmental monitoring. To date, taxonomy of the species populating a water column is still conducted by marine biologists on the basis of their own experience. On the other hand, deep learning is recognized as the elective technique for solving image classification problems. However, a large amount of training data is usually needed, thus requiring the synthetic enlargement of the dataset through data augmentation. In the case of microalgae, the large variety of species that populate the marine environments makes it arduous to perform an exhaustive training that considers all the possible classes. However, commercial test slides containing one diatom element per class fixed in between two glasses are available on the market. These are usually prepared by expert diatomists for taxonomy purposes, thus constituting libraries of the populations that can be found in oceans. Here we show that such test slides are very useful for training accurate deep Convolutional Neural Networks (CNNs). We demonstrate the successful classification of diatoms based on a proper CNNs ensemble and a fully augmented dataset, i.e., creation starting from one single image per class available from a commercial glass slide containing 50 fixed species in a dry setting. This approach avoids the time-consuming steps of water sampling and labeling by skilled marine biologists. To accomplish this goal, we exploit the holographic imaging modality, which permits the accessing of a quantitative phase-contrast maps and a posteriori flexible refocusing due to its intrinsic 3D imaging capability. The network model is then validated by using holographic recordings of live diatoms imaged in water samples i.e., in their natural wet environmental condition.

Interaction between medical image platform and external environment is a desirable feature in several clinical, research, and educational scenarios. In this work, the integration between 3D Slicer package and Arduino board is introduced, enabling a simple and useful communication between the two software/hardware platforms. The open source extension, programmed in Python language, manages the connection process and offers a communication layer accessible from any point of the medical image suite infrastructure. Deep integration with 3D Slicer code environment is provided and a basic input–output mechanism accessible via GUI is also made available. To test the proposed extension, two exemplary use cases were implemented: (1) INPUT data to 3D Slicer, to navigate on basis of data detected by a distance sensor connected to the board, and (2) OUTPUT data from 3D Slicer, to control a servomotor on the basis of data computed through image process procedures. Both goals were achieved and quasi-real-time control was obtained without any lag or freeze, thus boosting the integration between 3D Slicer and Arduino. This integration can be easily obtained through the execution of few lines of Python code. In conclusion, SlicerArduino proved to be suitable for fast prototyping, basic input–output interaction, and educational purposes. The extension is not intended for mission-critical clinical tasks.

Objective: To test a new bipolar electrode for electroporation consisting of a single minimally invasive needle. Methods: A theoretical study was performed by using Comsol Multiphysics® software. The prototypes of electrode have been tested on potatoes and pigs, adopting an irreversible electroporation protocol. Different applied voltages and different geometries of bipolar electrode prototype have been evaluated. Results: Simulations and pre-clinical tests have shown that the volume of ablated area is mainly influenced by applied voltage, while the diameter of the electrode had a lesser impact, making the goal of minimal-invasiveness possible. The conductive pole’s length determined an increase of electroporated volume, while the insulated pole length inversely affects the electroporated volume size and shape; when the insulated pole length decreases, a more regular shape of the electric field is obtained. Moreover, the geometry of the electrode determined a different shape of the electroporated volume. A parenchymal damage in the liver of pigs due to irreversible electroporation protocol was observed. Conclusion: The minimally invasive bipolar electrode is able to treat an electroporated volume of about 10 mm in diameter by using a single-needle electrode. Moreover, the geometry and the electric characteristics can be selected to produce ellipsoidal ablation volumes.

In the current clinical practice, the diagnosis of Rheumatoid Arthritis (RA) draws on the qualitative evaluation of pain sensitivity thresholds which is affected by several source of uncertainties, due to an operator-dependent diagnostic protocol. Taking our cue from the diagnostic shortcomings, we have explored the possibility of automating the measurement of mechanical nociceptive thresholds through the adoption of soft pneumatic actuators controlled by an embedded control unit. In this work, we want to show that a purpose-made biomechatronic device actuated by soft and pneumatic actuators is potentially a boon both for rheumatologists and biomedical researchers involved in nociception and physicophysical studies. In the full breadth and scope of the objective diagnosis of RA, the first prototype of a novel biomechatronic device for quantitative and automatic measurement of mechanical nociceptive thresholds has been designed and tested through nociception experiments on 10 subjects. The experimental results show that the designed device can reliably generate the controllable and repeatable nociceptive stimuli needed for the objective diagnosis of RA.

Montenegro is a land of great history which needs attention and care for a deeper knowledge and its making at the disposal of new generations. It is still a territory to be discovered, studied, and disclosed. It is important to understand how much hidden heritage there is still in this area to explore and exploit, but on the other hand, how much known heritage exists to protect and monitor, preventing its destruction and loss. In this context, Montenegro is heavily investing in the management of cultural heritage through initiatives for identification, protection, preservation, enhancement and fruition of them. In the frame of the knowledge, the use of non-destructive geophysical methods can be helpful for a cognitive investigation immediately in the bud of any archaeological verification project, safeguarded through preventive archaeology operations and the exploration of large areas within archaeological parks. In this paper, the results of geophysical prospections at the Hellenistic-Illyrian site of Mjace, the roman towns of Doclea and Municipium S, the medieval city of Svač, and the Stećci medieval tombstones graveyards of Novakovići, Žugića, and Plužine are presented. The study allowed the reconnaissance of new buried structures in the soil and has provided an updated view of the rich archaeological heritage of Montenegro.

Amino acid complexes of transition metals show interesting hydrogen-bonding motifs. In this paper, the syntheses and structures of three β-amino acid complexes of palladium that differ only by the substitution on the β-carbon will be discussed. With only hydrogen on the β-carbon, no additional water is incorporated into the crystal lattice and hydrogen-bonding is all complex-to-complex. With the addition of one and two methyl groups on the amino acid β-carbon, water is incorporated into the crystal lattice giving intricate water networks held together by complex-to-water and water-to-water hydrogen-bonding networks.

These days, biomimetic and compliant actuators have been made available to the main applications of rehabilitation and assistive robotics. In this context, the interaction control of soft robots, mechatronic surgical instruments and robotic prostheses can be improved through the adoption of pneumatic artificial muscles (PAMs), a class of compliant actuators that exhibit some similarities with the structure and function of biological muscles. Together with the advantage of implementing adaptive compliance control laws, the nonlinear and hysteretic force/length characteristics of PAMs pose some challenges in the design and implementation of tracking control strategies. This paper presents a parsimonious and accurate model of the asymmetric hysteresis observed in the force response of PAMs. The model has been validated through the experimental identification of the mechanical response of a small-sized PAM where the asymmetric effects of hysteresis are more evident. Both the experimental results and a comparison with other dynamic friction models show that the proposed model could be useful to implement efficient compensation strategies for the tracking control of soft robots.

To mitigate the increasing concentration of carbon dioxide in the atmosphere, energy production processes must change from fossil to renewable resources. Bioenergy utilization from agricultural residues can be a step towards achieving this goal. Syngas (fuel obtained from biomass gasification) has been proved to have the potential of replacing fossil fuels in stationary internal combustion engines (ICEs). The processes associated with switching from traditional fuels to alternatives have always led to intense research efforts in order to have a broad understanding of the behavior of the engine in all operating conditions. In particular, attention needs to be focused on fuels containing relatively high concentrations of hydrogen, due to its faster propagation speed with respect to traditional fossil energy sources. Therefore, a combustion study was performed in a research optical SI engine, for a comparison between a well-established fuel such as methane (the main component of natural gas) and syngas. The main goal of this work is to study the effect of inert gases in the fuel mixture and that of air dilution during lean fuelling. Thus, two pure syngas blends (mixtures of CO and H2) and their respective diluted mixtures (CO and H2 with 50vol% of inert gases, CO2 and N2) were tested in several air-fuel ratios (stoichiometric to lean burn conditions). Initially, the combustion process was studied in detail by traditional thermodynamic analysis and then optical diagnostics were applied thanks to the optical access through the piston crown. Specifically, images were taken in the UV-visible spectrum of the entire cycle to follow the propagation of the flame front. The results show that hydrogen promotes flame propagation and reduces its distortion, as well as resulting in flames evolving closer to the spark plug. All syngas blends show a stable combustion process, even in conditions of high air and fuel dilution. In the leanest case, real syngas mixtures present a decrease in terms of performance due to significant reduction in volumetric efficiency. However, this condition strongly decreases pollutant emissions, with nitrogen oxide (NOx) concentrations almost negligible.

Direct-injection in spark-ignition engines has long been recognized as a valid option for improving fuel economy, reducing CO2 emissions and avoiding knock occurrence due to higher flexibility in control strategies. However, problems associated with mixture formation are responsible for soot emissions, one of the most limiting factors of this technology. Therefore, the combustion process and soot formation were investigated with different injection strategies on a gasoline direct injection (GDI) engine. The experimental analysis was realized on an optically accessible single cylinder engine when applying single, double and triple injection strategies. Moreover, the effect of fuel delivery phasing was also scrutinized by changing the start of the injection during late intake- and early compression-strokes. The duration of injection was split in different percentages between two or three pulses, so as to obtain close to stoichiometric operation in all conditions. The engine was operated at fixed rotational speed and spark timing, with wide-open throttle. Optical diagnostics based on cycle resolved digital imaging was applied during the early and late stages of the combustion process. Detailed information on the flame front morphology and soot formation were obtained. The optical data were correlated to in-cylinder pressure traces and exhaust gas emission measurements. The results suggest that the split injection of the fuel has advantages in terms of reduction of soot formation and NOx emissions and a similar combustion performance with respect to the single injection timing. Moreover, an early injection resulted in higher rates of heat release and in-cylinder pressure, together with a reduction of soot formation and flame distortion. The double injection strategy with higher percentage of fuel injected in the first pulse and early second injection pulse showed the best results in terms of combustion evolution and pollutant emissions. For the operative condition studied, a higher time for mixture homogenization and split of fuel injected in the intake stroke shows the best results.

Lean fueling of spark ignited (SI) engines is a valid method for increasing efficiency and reducing nitric oxide (NOx) emissions. Gasoline direct injection (GDI) allows better fuel economy with respect to the port-fuel injection configuration, through greater flexibility to load changes, reduced tendency to abnormal combustion, and reduction of pumping and heat losses. During homogenous charge operation with lean mixtures, flame development is prolonged and incomplete combustion can even occur, causing a decrease in stability and engine efficiency. On the other hand, charge stratification results in fuel impingement on the combustion chamber walls and high particle emissions. Therefore, lean operation requires a fundamentally new understanding of in-cylinder processes for developing the next generation of direct-injection (DI) SI engines. In this paper, combustion was investigated in an optically accessible DISI single cylinder research engine fueled with gasoline. Stoichiometric and lean operations were studied in detail through a combined thermodynamic and optical approach. The engine was operated at a fixed rotational speed (1000 rpm), with a wide open throttle, and at the start of the injection during the intake stroke. The excess air ratio was raised from 1 to values close to the flammability limit, and spark timing was adopted according to the maximum brake torque setting for each case. Cycle resolved digital imaging and spectroscopy were applied; the optical data were correlated to in-cylinder pressure traces and exhaust gas emission measurements. Flame front propagation speed, flame morphology parameters, and centroid motion were evaluated through image processing. Chemical kinetics were characterized based on spectroscopy data. Lean burn operation demonstrated increased flame distortion and center movement from the location of the spark plug compared to the stoichiometric case; engine stability decreased as the lean flammability limit was approached.

Within the context of ever wider expansion of direct injection in spark ignition engines, this investigation was aimed at improved understanding of the correlation between fuel injection strategy and emission of nanoparticles. Measurements performed on a wall guided engine allowed identifying the mechanisms involved in the formation of carbonaceous structures during combustion and their evolution in the exhaust line. In-cylinder pressure was recorded in combination with cycle-resolved flame imaging, gaseous emissions and particle size distribution. This complete characterization was performed at three injection phasing settings, with butanol and commercial gasoline. Optical accessibility from below the combustion chamber allowed visualization of diffusive flames induced by fuel deposits; these localized phenomena were correlated to observed changes in engine performance and pollutant species. With gasoline fueling, minor modifications were observed with respect to combustion parameters, when varying the start of injection. The alcohol, on the other hand, featured marked sensitivity to the fuel delivery strategy. Even though the start of injection was varied in a relatively narrow crank angle range during the intake stroke, significant differences were recorded, especially in the values of particle emissions. This was correlated to the fuel jet-wall interactions; the analysis of diffusive flames, their location and size confirmed the importance of liquid film formation in direct injection engines, especially at medium and high load.

In this research, we developed a direct-flow surface plasmon resonance (SPR) immunosensor for ampicillin to perform direct, simple, and fast measurements of this important antibiotic. In order to better evaluate the performance, it was compared with a conventional amperometric immunosensor, working with a competitive format with the aim of finding out experimental real advantages and disadvantages of two respective methods. Results showed that certain analytical features of the new SPR immunodevice, such as the lower limit of detection (LOD) value and the width of the linear range, are poorer than those of a conventional amperometric immunosensor, which adversely affects the application to samples such as natural waters. On the other hand, the SPR immunosensor was more selective to ampicillin, and measurements were more easily and quickly attained compared to those performed with the conventional competitive immunosensor.

This paper deals with the study of the enhancement of the tribological properties of AA2024 through the deposition of a titanium coating. In particular two different coatings were studied: (1) untreated titanium coating; and (2) post-deposition laser-treated titanium coating. Titanium grade 2 powders were deposited onto an aluminium alloy AA2024-T3 sheet through the cold gas dynamic spray process. The selective laser post treatment was carried out by using a 220 W diode laser to further enhance the wear properties of the coating. Tribo-tests were executed to analyse the tribological behaviour of materials in contact with an alternative moving counterpart under a controlled normal load. Four different samples were tested to assess the effectiveness of the treatments: untreated aluminium sheets, titanium grade 2 sheets, as-sprayed titanium powders and the laser-treated coating layer. The results obtained proved the effectiveness of the coating in improving the tribological behaviour of the AA2024. In particular the laser-treated coating showed the best results in terms of both the friction coefficient and mass lost. The laser treatment promotes a change of the wear mechanism, switching from a severe adhesive wear, resulting in galling, to an abrasive wear mechanism.