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The widespread use of hydrogen as an energy carrier for road transport and industrial applications was indicated as a promising solution for reducing pollutant emissions. The high flammability of this substance and its tendency to permeate and embrittle most structural materials make hydrogen handling and storage inherently challenging. Hence, inspection and maintenance activities are essential to guarantee the components' integrity and fitness for service. However, guidelines for inspecting and maintaining hydrogen refueling stations are still under development. The manufacturer is responsible for indicating the optimal inspection procedures for each facility. The lack of a unified regulatory framework and the limited operational experience with these technologies make human errors a potential cause of undesired events. In this context, the study evaluates the probability of human error during the high-pressure storage system inspection procedures in hydrogen refueling stations. The Petro-HRA methodology has been used to quantify the likelihood of unsafe or inappropriate actions. In addition, a Bayesian Network approach is proposed to investigate the conditional dependencies among human errors and performance shaping factors. The critical analysis of the results allowed the authors to provide recommendations regarding safety procedures that operators can adopt to reduce the likelihood of accidents in the hydrogen industry.

Hydrogen is assuming a pivotal role in the energy sector, intending to lead the decarbonization and overcome the fossil fuel use. In evaluating its key applications, the role of hydrogen in mobility stands out. It could transform one of the most polluting sectors, drastically reducing emissions without changing the drivers’ needs. In this perspective, the focus should be placed on hydrogen refueling infrastructures, which are a key factor, along with fuel cell vehicles, for extending the hydrogen chain in the mobility sector. Given this, the study analyzes the hydrogen refueling station performance, investigating the hydrogen flow features, and estimating the evolution of pressure and temperature within the vehicle tank. An ad-hoc model for hydrogen performance analysis is used by customizing its main blocks. In addition, the main safety aspects of the hydrogen refueling stations are evaluated. The behavior of each component of the refueling infrastructure, such as hydrogen storage tanks, compressors, and cooling systems, is examined and introduced in the model, characterizing the whole system. The model is then validated by comparing its performance with experimental data. The results show the pressure, temperature, and mass flow rate between the dispenser and the vehicle tank. These findings could help boost hydrogen use in mobility since crucial aspects are investigated and important information is provided for promising integrated systems, based on the interconnection between infrastructures and vehicles.

Pancreatitis, in general, is a high-morbidity condition. Genetic conditions and anatomic variants are sometimes seen, especially in children, where biliary etiologies and alcohol are less common than in adults. The decision to intervene, the combined operative-endoscopic strategy, and the timing pose unique challenges. We report the case of a 10-year-old boy with PRSS1 mutation and pancreatic duct duplication, discussing the management and reviewing the recent reports in the Literature.

Aim of the Study: To assess how virtual reality (VR) patient-specific simulations can support decision-making processes and improve care in pediatric urology, ultimately improving patient outcomes. Patients and Methods: Children diagnosed with urological conditions necessitating complex procedures were retrospectively reviewed and enrolled in the study. Patient-specific VR simulations were developed with medical imaging specialists and VR technology experts. Routine CT images were utilized to create a VR environment using advanced software platforms. The accuracy and fidelity of the VR simulations was validated through a multi-step process. This involved comparing the virtual anatomical models to the original medical imaging data and conducting feedback sessions with pediatric urology experts to assess VR simulations’ realism and clinical relevance. Results: A total of six pediatric patients were reviewed. The median age of the participants was 5.5 years (IQR: 3.5–8.5 years), with an equal distribution of males and females across both groups. A minimally invasive laparoscopic approach was performed for adrenal lesions (n = 3), Wilms’ tumor (n = 1), bilateral nephroblastomatosis (n = 1), and abdominal trauma in complex vascular and renal malformation (ptotic and hypoplastic kidney) (n = 1). Key benefits included enhanced visualization of the segmental arteries and the deep vascularization of the kidney and adrenal glands in all cases. The high depth perception and precision in the orientation of the arteries and veins to the parenchyma changed the intraoperative decision-making process in five patients. Preoperative VR patient-specific simulation did not offer accuracy in studying the pelvic and calyceal anatomy. Conclusions: VR patient-specific simulations represent an empowering tool in pediatric urology. By leveraging the immersive capabilities of VR technology, preoperative planning and intraoperative navigation can greatly impact surgical decision-making. As we continue to advance in medical simulation, VR holds promise in educational programs to include even surgical treatment of more complex urogenital malformations.

The issue of global warming imposes a change of paradigm in the energy sector to mitigate the human impact on the environment. In this perspective, hydrogen can be produced through water electrolysis and used in fuel-cell systems with near-zero pollutant emissions. Nevertheless, the distribution system represents one of the main bottlenecks for a future transition to a hydrogen economy. The possibility of transporting hydrogen through the existing pipeline network is economically attractive. Nevertheless, most pipeline steels are prone to hydrogen-induced damage, and their mechanical properties are degraded by hydrogen gas to an extent that could result in sudden component failures. Hydrogen embrittlement can be responsible for undesired releases with potentially catastrophic consequences. This study evaluates the safety of existing European natural gas pipelines for hydrogen transport through machine learning tools. The material susceptibility to hydrogen embrittlement is predicted under different working conditions in order to prevent loss of material integrity and eventual releases. This study aims at bridging the gap between safety and material science, as it can optimize predictive maintenance of hydrogen pipelines, thus promoting the widespread utilization of hydrogen in the forthcoming years.

Hydrogen has the potential to promote sustainable road transport in the forthcoming years, thus significantly reducing the human impact on the environment. This energy carrier can be produced by renewable energy through water electrolysis and used in fuel cell-powered vehicles (FCVs) with elevated efficiency and no pollutant emissions. The number of FCVs being used around the world is rapidly increasing, reaching 34,804 vehicles and 540 refueling stations by the end of 2020. Nevertheless, hydrogen is highly flammable and can permeate and embrittle most metallic materials, making its containment extremely challenging. A leak in a hydrogen refueling station can rapidly escalate to a major disaster if not promptly detected and addressed. In this perspective, gas sensors play a critical role in detecting leakages and undesired hydrogen releases. When selecting a hydrogen gas detector, it is important to consider the environmental conditions in which it is expected to operate, its performance, reliability, and cost, as well as the optimal positioning within the refueling station. This study analyzes several hydrogen releases from a high-pressure storage tank to optimize sensor positioning, given a certain detection probability. This research contributes towards advancing the modelling of safety barriers in hydrogen refueling stations considering accident scenarios. In this vein, this study aims at expanding the current knowledge of facility operators and stakeholders for related risks, thus enabling the widespread utilization of hydrogen in road transport.

Introduction: A trichobezoar is a mass of indigestible hair in the gastrointestinal tract caused by hair ingestion, usually associated with trichotillomania and trichophagia. Although sometimes asymptomatic, it can become a rare cause of intestinal obstruction and require an emergent surgical intervention. The operative approach of choice, laparotomy versus laparoscopy, is still controversial. Case presentation: A 11-year-old girl was admitted to our institution with abdominal pain, vomiting and anorexia for 3 days. On abdominal examination, she had diffused abdominal pain with tenderness in the mesogastrium, with no palpable mass. Abdominal computed tomography (CT) scan and barium meal study shown a large gastric mass. Upper gastrointestinal (GI) endoscopy identified an enormous trichobezoar, which was later removed laparoscopically. An anterior gastrotomy was performed and the bezoar was then transferred en bloc into the endo-bag. The neck of the endobag was then exteriorized through the umbilical incision and removed by gradual fragmentation. The volume and size of the phytobezoars were 1875 cm3 and 25 × 15 × 5 cm. The patient was discharged on the 5th postoperative day without any complications. Conclusion: Successful laparoscopic management of pediatric trichobezoar may be accomplished by a 4-ports approach. It allows a lower intraoperative risk of contaminations, a rapid recovery and good cosmetic results in children.

Hydrogen is widely considered a promising energy carrier capable of mitigating human environmental impact. Nevertheless, safety aspects represent one of the major bottlenecks for the widespread utilization of hydrogen technologies. Industrial equipment operating in hydrogen environments is prone to hydrogen-induced damages, which may manifest through a reduction of mechanical properties, fracture toughness, and fatigue performance. They may cause component failures at stress levels significantly below the design level, therefore determining loss of containment. The occurrence of hydrogen embrittlement (HE) relies on the synergy of several factors, such as hydrogen concentration, operating conditions, level of internal and applied stress, microstructure and chemical composition of the material. However, the interlinked dependence of these factors makes a direct and clear evaluation challenging, subsequently creating serious difficulties in planning inspection and maintenance activities. In this study, a comprehensive review of the experimental data of tensile tests carried out in hydrogen was performed and analyzed through an advanced machine learning approach. This study can provide critical insights into the susceptibility to hydrogen embrittlement for several materials operating under different environmental conditions. In particular, the Embrittlement Index was estimated and used as determining parameter to predict the likelihood of component failures. The model demonstrated accurate and reliable predicting capabilities. The outcome of this study can increase the understanding of hydrogen-induced material damages and facilitate decision-making processes in planning the inspection and maintenance of hydrogen technologies.

Hydrogen is considered a promising energy carrier to achieve the ambitious target of a zero-emission society in the forthcoming years. Despite its environmental advantages, hydrogen-induced material damages represent a serious safety concern. Hence, inspection and maintenance activities must be performed to guarantee the equipment's integrity. The risk-based inspection (RBI) is the most beneficial methodology for inspection planning but has never been adopted for components operating in hydrogen environments. The probability of failure of each piece of equipment is quantified through the definition of the damage factor, a parameter that accounts for the damage mechanism likely to occur. Hydrogen embrittlement (HE) is the main active degrading mechanism in equipment exposed to hydrogenated environments; if not appropriately accounted for, it can cause failures at unexpectedly low stress levels. This study aims to bridge a gap in knowledge by proposing a qualitative methodology to assess the degradation of equipment operating in hydrogenated environments and potentially subjected to HE. The environmental severity is estimated based on the operating conditions, while the material’s susceptibility depends on microstructure, strength, and adoption of post-weld heat treatments. This study could set the basis for the application of the RBI methodology to industrial equipment for producing, handling, and storing hydrogen. Hence, it will facilitate the inspection and maintenance of emerging hydrogen technologies.

Hydrogen has not only the potential of tackling climate-related issues by replacing fossil fuels, but it also plays a main role in the energy transition which will have several geopolitical implications. According to the International Renewable Energy Agency (IRENA), relations between countries and communities will be transformed by “a new energy age” changing the concept of power, security, energy independence and prosperity. For these reasons, the interest in hydrogen recently skyrocketed as shown by the hydrogen strategies developed by many countries in the world. This will result in a considerable increase of hydrogen produced, stored, and consumed worldwide in the near future. Safety aspects must always be considered during the whole hydrogen lifecycle. The aim of this study is to pinpoint the consequences of failure for hydrogen technologies and the most common types of techniques developed and validated to assess them. Different types of models including theoretical and numerical ones were adopted to assess these consequences in the past. The advantages and drawbacks of these types of techniques are highlighted in this work. The intent is to provide critical insights to analysts carrying out the risk assessment in order to improve the overall safety of hydrogen technologies.

Background: In children, laparoscopic cholecystectomy (LC) is now considered the gold standard for gallbladder (GB) removal. In the past, hemolytic disorders associated with cholelithiasis represented the most frequent conditions requiring LC; this is being overtaken by cholelithiasis and biliary conditions in overweight or ex-premature children. Aims: This study aims to describe current indications and timing for LC in pediatric patients. Methods: Retrospective study. Data on previous medical therapy, ultrasound, pre- and intraoperative aspects, and histology were collected for patients treated in 2020–2023. Results: In total, 45 patients were enrolled: 15 who underwent urgent surgery and 30 electives. Groups differed in terms of obesity rate, symptoms, ultrasound features, and intraoperative status. The most relevant risk factors for surgical complexity were age and pubertal stage, elevated cholestasis indexes, and gallbladder wall thickness > 3 mm at ultrasound. GB wall thickening ≥3 mm, US Murphy sign, fluid collections, and gallbladder distention on ultrasound correlated with high surgical scores. Conclusions: Indications for laparoscopic cholecystectomy in children seem to evolve caused by changing characteristics of the pediatric population. Patients with overweight/obesity may develop more complex GB diseases. Asymptomatic patients should be considered for surgery after observation, considering age and/or pubertal maturation when other risk factors are absent.

The adoption of hydrogen has been largely indicated as a feasible solution to support society in achieving its ambitious targets for a low-carbon future. The increased knowledge in liquefaction techniques has encouraged the study of technological solutions based on liquid hydrogen (LH2). Moreover, handling and distribution under cryogenic conditions represent attractive options due to the elevated energy density of LH2. Despite these advantages, the bottleneck for its widespread adoption is represented by safety aspects. Considering that an LH2 tank truck has a probability of suffering a car accident like all other road vehicles, an emergency auto-thermal burner has been designed in this work. This safety system has the purpose to dispose of the content of a tank truck to avoid the loss of containment. The disposal process includes the vaporization and pre-heating of the LH2, the mixing with ambient air, and its combustion. This device is completely self-supporting since the heat required to vaporize the LH2 is entirely provided by the combustion of the fuel itself. Firstly, the equation of energy balance around the burner was numerically solved to estimate the temperature of flue gases. Then, inner and outer heat transfer coefficients were determined for each section of the coiled-tube heat exchanger. Finally, the heat transfer surface was calculated. The spontaneous conversion between two spin isomers of hydrogen was considered. From the perspective of the heating process, the enthalpy of conversion represents an additional energy request. If the decrease of para-hydrogen fraction was neglected, the length of the heat exchanger would be significantly underestimated. Based on the obtained results, it is possible to conclude that the designed device can be transported on-site and started up easily, making it suitable for emergency response.

Introduction: Endoscopic procedures are performed more frequently in children due to technological advances that can be safely performed in an adequate setting with a support of a multidisciplinary team. Pediatric indications for ERCP (endoscopic retrograde cholangiopancreatography) and EUS (endoscopic ultrasound) occur mainly due to congenital malformations. In a pediatric case series, we report the application of EUS combined with duodenoscopy, eventually associated with ERCP and minimally invasive surgery, highlighting the importance of defining a tailored dedicated management pathway for each patient. Patients and methods: A series of 12 patients, managed at our Center in the last three years, were evaluated, and their management was discussed. Results: EUS was performed in eight patients and permitted the differential diagnosis of duplication cysts and the visualization of the biliary tree and pancreatic anatomy. ERCP was attempted in five patients: in one case, it permitted the preservation of pancreatic tissue, postponing surgery and in three patients, it was technically unfeasible. MIS (minimally invasive surgery) was performed in seven patients, two with laparoscopic common bile duct exploration (LCBDE). Precise anatomical definition and the possibility of surgical simulation and team sharing were evaluated under VR HMD (Virtual Reality Head Mounted Display) in four cases. Conclusions: Exploration of the common bile duct in children differs from that of the adult population and combines echo-endoscopy and ERCP. The integrated use of minimally invasive surgery in the pediatric area is necessary for the whole management perspective in complex malformations and small patients. The introduction in the clinical practice of a preoperative study with Virtual Reality allows a better survey of the malformation and a tailored treatment.

The European Green Deal aims to transform the EU into a modern, resource-efficient, and competitive economy. The REPowerEU plan launched in May 2022 as part of the Green Deal reveals the willingness of several countries to become energy independent and tackle the climate crisis. Therefore, the decarbonization of different sectors such as maritime shipping is crucial and may be achieved through sustainable energy. Hydrogen is potentially clean and renewable and might be chosen as fuel to power ships and boats. Hydrogen technologies (e.g., fuel cells for propulsion) have already been implemented on board ships in the last 20 years, mainly during demonstration projects. Pressurized tanks filled with gaseous hydrogen were installed on most of these vessels. However, this type of storage would require enormous volumes for large long-range ships with high energy demands. One of the best options is to store this fuel in the cryogenic liquid phase. This paper initially introduces the hydrogen color codes and the carbon footprints of the different production techniques to effectively estimate the environmental impact when employing hydrogen technologies in any application. Afterward, a review of the implementation of liquid hydrogen (LH2) in the transportation sector including aerospace and aviation industries, automotive, and railways is provided. Then, the focus is placed on the maritime sector. The aim is to highlight the challenges for the adoption of LH2 technologies on board ships. Different aspects were investigated in this study, from LH2 bunkering, onboard utilization, regulations, codes and standards, and safety. Finally, this study offers a broad overview of the bottlenecks that might hamper the adoption of LH2 technologies in the maritime sector and discusses potential solutions.

Objective and design: Following COVID-19 infection, children can develop an hyperinflammatory state termed Multisystem Inflammatory Syndrome in Children (MIS-C). Lung Ultrasound (LUS) features of COVID-19 in children have been described, but data describing the LUS findings of MIS-C are limited. The aim of this retrospective observational study conducted between 1 March and 31 December 2020, at a tertiary pediatric hospital in Milano, is to describe LUS patterns in patients with MIS-C and to verify correlation with illness severity. The secondary objective is to evaluate concordance of LUS with Chest X-ray (CXR). Methodology: Clinical and laboratory data were collected for all patients (age 0–18 years) admitted with MIS-C, as well as LUS and CXR patterns at admission. PICU admission, needed for respiratory support and inotrope administration, hospital, and PICU length of stay, were considered as outcomes and evaluated in the different LUS patterns. An agreement between LUS and CXR evaluation was assessed with Cohen’ k. Results: 24 children, who had a LUS examination upon admission, were enrolled. LUS pattern of subpleural consolidations < or > 1 cm with or without pleural effusion were associated with worse Left Ventricular Ejection Fraction at admission and need for inotropes. Subpleural consolidations < 1 cm were also associated with PICU length of stay. Agreement of CXR with LUS for consolidations and effusion was slight. Conclusion: LUS pattern of subpleural consolidations and consolidations with or without pleural effusion are predictors of disease severity; under this aspect, LUS can be used at admission to stratify risk of severe disease.

Video assisted thoracoscopic surgery (VATS) has been adopted in pediatric age for the treatment of congenital lung malformations (CLM). The success of VATS in pediatrics largely depends on the surgeon’s skill ability to understand the airways, vascular system and lung parenchyma anatomy in CLM. In the last years, virtual reality (VR) and 3-dimensional (3D) printing of organ models and VR head mounted display (HMD) technologies have been introduced for completion of preoperative planning in adult patients. To date no reports about the use of VR HMD technologies in a pediatric setting are available. The aim of this report is to introduce a VR HMD model in VATS procedure to improve the quality of care in children with CLM. VR HMD set-up for planning thoracoscopic surgery was performed in a series of pediatric patients with diagnosis of CLM. The preoperative VR HMD evaluation allowed a navigation into the malformation with the aim to explore, interact, and make the surgeon more confident and skilled to answer to the traps. A development of surgical simulations models and teaching program dedicated to education and training in pediatric VATS is suitable among the pediatric surgery community. Further studies should demonstrate all the benefits of such technology in pediatric patients submitted to VATS procedure.

Colonic volvulus (CV) is a rare but potentially life-threatening condition with unclear etiopathogenesis. To date, less than 80 pediatric cases have been described. Hirschsprung’s disease (HD) is associated with CV in 17% of cases, representing a significant risk factor. Non-HD CV is an even more complex entity. The aim of this study is to describe a series of patients with CV to accentuate some peculiar aspects of this disease. We performed a retrospective study (period: 2012–2021) collecting information of patients with CV. Data analyzed included: demographics, medical history, presenting symptoms and radiological and surgical details. Eleven patients (12.5 ± 2.8 years; 7F/4M) had CV (eight sigmoid, two transverse colon, one total colon). Five patients had associated anomalies and three had HD. A two-step approach with volvulus endoscopic/radiological detorsion followed by intestinal resection was attempted in eight cases (one endoscopic approach failed). Three patients required surgery at admission. At follow-up, two patients developed recurrent intestinal obstruction, one of whom also had anastomotic stenosis. Colonic volvulus is a challenging condition that requires prompt patient care. A missed diagnosis could lead to severe complications. The evaluation of the patient should include a careful histological examination (searching for HD and alpha-actin deficiency), immunologic and metabolic screening, neurological tests and detection of chronic intestinal pseudo-obstruction (CIPO). Lifelong follow-up is mandatory for the early recognition and treatment of progressive diseases involving the proximal gastrointestinal tract.