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In this paper a numerical investigation on mixed convection in confined slot jets impinging on a partially filled configuration of porous medium by considering pure water or Al2O3/water based nanofluids is described. A two-dimensional model is developed and different Peclet numbers are considered. Rayleigh numbers is imposed equal to 30000. The particle volume concentration ranges from 0% to 4% and the particle diameter is assumed equal to 20, 30 and 80 nm. The target surface is heated at constant temperature value, calculated according to the value of Rayleigh number. The distance of the target surface is five times greater than the slot jet width. Three different values of the ratio between the total system length and metal foam length are considered. A single-phase model approach is employed in order to describe the nanofluid behaviour while the hypothesis of non-local thermal equilibrium is assumed to simulate the thermal behaviour in the metal foam. The foam is characterized by a number of pores per inch equal to 5, 10, 20 and 40 and a porosity around 0.90. The aim of the paper consists to study the thermal and fluid-dynamic behaviour of the impinging jet system with nanofluids. Results show increasing values of the Nusselt number for increasing values of Peclet number and nanoparticle concentration. In addition, the ratio between the thermal and pumping power is evaluated to find a trade-off between the increase of heat transfer and pressure drop.

Thermal storage system (TES) with phase change material (PCM) is an important device to store thermal energy. It works as a thermal buffer to reconcile the supply energy with the energy demand. It has a wide application field, especially for solar thermal energy storage. The main drawback is the low value of thermal conductivity of the PCM making the system useless for thermal engineering applications. A way to resolve this problem is to combine the PCM with a highly conductive material like metal foam and/or nanoparticles. In this paper a numerical investigation on the metal foam effects in a latent heat thermal energy storage system, based on a phase change material with nanoparticles (nano-PCM), is accomplished. The modelled TES is a typical 70 L water tank filled with nano-PCM with pipes to transfer thermal energy from a fluid to the nano-PCM. The PCM is a pure paraffin wax and the nanoparticles are in aluminum oxide. The metal foam is made of aluminum with assigned values of porosity. The enthalpy-porosity theory is employed to simulate the phase change of the nano-PCM and the metal foam is modelled as a porous media. Numerical simulations are carried out using the Ansys Fluent code. The results are shown in terms of melting time, temperature at varying of time, and total amount of stored energy.

Les mousses métalliques constituent une catégorie relativement récente de matériaux utilisés dans différentes applications, telles que: dissipateurs de chaleur compacts, opérations géothermiques, échangeurs de chaleur et centrales thermiques solaires. L'utilisation de mousses métalliques dans les échangeurs de chaleur leur confère efficacité, compacité et légèreté pour la porosité ouverte, une conductivité thermique élevée et une grande surface accessible par unité de volume. Une étude numérique a été menée pour évaluer les comportements thermiques et hydrodynamiques d'un échangeur de chaleur tubulaire en mousse d’aluminium. La condition d’énergie non thermique d’équilibre est considérée comme ce qui permet d’exécuter des simulations bi-dimensionnelles sur l’échangeur thermique en mousse métallique. Les mousses examinées sont caractérisées par une porosité distincte, de 0,90 à environ 0,97, pour différentes valeurs de pores par pouce égales à 5, 10, 20 et 40. Différents débits d'air et une température de tube de surface assignée sont imposés. Les résultats sont donnés en termes de coefficient de transfert de chaleur et de nombre de Nusselt local évalués sur la surface externe du tube. Les paramètres globaux typiques dans un échangeur de chaleur compact, tels que l'efficacité et le NTU, sont présentés. De plus, les profils de température et de vitesse de l'air local sont présentés dans la section transversale, entre deux tubes consécutifs. Enfin, le Rapport Performance Énergie (RPE) est présenté afin de démontrer l'efficacité des mousses métalliques. Metal foams are a relatively recent category of materials used in different applications, such as: compact heat sinks, geothermal operations, heat exchanger and solar thermal plants. The use of metal foams in heat exchangers gives it efficiency, compact and light for the open porosity, a high thermal conductivity and a large accessible surface area per unit volume. A numerical study has been conducted to evaluate the thermal and fluid dynamic behaviors of a tubular aluminum foam heat exchanger. The thermal non-equilibrium energy condition is considered to execute two-dimensional simulations on metal foam heat exchanger. The examined foams are characterized by distinct porosity, from 0.90 to about 0.97, for different values of pores per inch, equal to 5, 10, 20 and 40. Different air flow rates and an assigned surface tube temperature are imposed. The results are given in terms of heat transfer coefficient and local Nusselt number evaluated on the external surface of the tube. Typical global parameters in a compact heat exchanger, such as effectiveness and NTU, are showed. Moreover, local air temperature and velocity profiles are presented in the cross section, between two consecutive tubes. Finally, the Energy Performance Ratio (EPR) is showed in order to demonstrate the effectiveness of the metal foams.

The autofluorescence of specific fatty acids, retinoids, and bilirubin in crude serum can reflect changes in liver functional engagement in maintaining systemic metabolic homeostasis. The role of these fluorophores as intrinsic biomarkers of pharmacological actions has been investigated here in rats administered with obeticholic acid (OCA), a Farnesoid-X Receptor (FXR) agonist, proven to counteract the increase of serum bilirubin in hepatic ischemia/reperfusion (I/R) injury. Fluorescence spectroscopy has been applied to an assay serum collected from rats submitted to liver I/R (60/60 min ± OCA administration). The I/R group showed changes in the amplitude and profiles of emission spectra excited at 310 or 366 nm, indicating remarkable alterations in the retinoid and fluorescing fatty acid balance, with a particular increase in arachidonic acid. The I/R group also showed an increase in bilirubin AF, detected in the excitation spectra recorded at 570 nm. OCA greatly reversed the effects observed in the I/R group, confirmed by the biochemical analysis of bilirubin and fatty acids. These results are consistent with a relationship between OCA anti-inflammatory effects and the acknowledged roles of fatty acids as precursors of signaling agents mediating damaging responses to harmful stimuli, supporting serum autofluorescence analysis as a possible direct, real-time, cost-effective tool for pharmacological investigations.

(1) Background: Several studies have reported associations between maternal diet in terms of single foods or nutrients and human milk compounds, while the overall role of maternal diet and related dietary patterns has rarely been investigated. (2) Methods: Between 2012 and 2014, we enrolled 300 healthy Italian mothers, who exclusively breastfed their infant. During a hospital visit at 6 weeks postpartum, a sample of freshly expressed foremilk was collected and information on maternal dietary habits in the postpartum period was obtained through an interviewer-administered food frequency questionnaire. We applied principal component factor analysis to selected nutrients in order to identify maternal dietary patterns, and assessed correlations in human milk macronutrients and fatty acids across levels of dietary patterns. (3) Results: Five dietary patterns were identified, named “Vitamins, minerals and fibre”, “Proteins and fatty acids with legs”, “Fatty acids with fins”, “Fatty acids with leaves”, “Starch and vegetable proteins”. These dietary patterns were correlated with some milk components, namely fatty acids, and in particular ω-3 and its subcomponents. (4) Conclusions: This study showed that overall maternal dietary habits during breastfeeding may influence human milk composition, suggesting the importance of adequate maternal nutrition during lactation not only for the mother herself but also to provide the infant with milk containing adequate amount and quality of nutrients for a balanced nutrition.

Autofluorescence (AF) of crude serum was investigated with reference to the potential of its intrinsic AF biomarkers for the noninvasive diagnosis of liver injury. Spectral parameters of pure compounds representing retinol (vitamin A) and fluorescing free fatty acids were characterized by spectrofluorometry, to assess spectral parameters for the subsequent AF analysis of serum, collected from rats undergoing liver ischemia/reperfusion (I/R). Differences in AF spectral profiles detected between control and I/R were due to the increase in the AF components representing fatty acids in I/R serum samples. No significant changes occurred for retinol levels, consistently with the literature reporting that constant retinol levels are commonly observed in the blood, except for malnutrition or chronic severe liver disease. Conversely, fatty acids, in particular arachidonic and linoleic acid and their derivatives, act as modulating agents in inflammation, representing both a protective and damaging response to stress stimuli. The biometabolic and pathophysiological meaning of serum components and the possibility of their direct detection by AF spectrofluorometry open up interesting perspectives for the development of AF serum analysis, as a direct, cost effective, supportive tool to assess liver injury and related systemic metabolic alterations, for applications in experimental biomedicine and foreseen translation to the clinics.

This review examines the pharmacology, efficacy and safety, dosage and administration, and place in therapy of the combination of 5-fluorouracil (5-FU) and calcipotriol for the treatment of actinic keratosis. Currently, 5% 5-FU topical cream is approved for actinic keratosis treatment, while calcipotriol is indicated for plaque psoriasis in adults. The typical administration of 5-FU involves topical application twice daily for up to 4 weeks, whereas calcipotriol is applied in a thin layer once or twice daily as directed by a physician. Adverse effects of 5-FU are primarily localized, including skin irritation, ulceration, pruritus, erythema, crusting, and eczematous reactions due to minimal systemic absorption. Calcipotriol may cause burning, itching, and skin irritation. This review details clinical trials that investigate the innovative approach of combining topical 5-FU with calcipotriol for actinic keratosis treatment, highlighting the significant outcomes. Notably, the clinical trials indicate that all participants experienced either a reduction in lesion size or complete lesion clearance, with minimal adverse effects impacting treatment success. The combination of 5-FU and calcipotriol effectively treats actinic keratosis by enhancing the immune response and targeting cell overgrowth, while reducing local site reactions and the lengthy treatment time often associated with existing therapies.

This study evaluated the protective role of farnesoid-X-receptor (FXR) agonist INT-787 in the control of mitochondrial changes using a metabolic dysfunction-associated steatohepatitis (MASH) model. Lep-ob/ob mice were fed a control diet (CD) for 21 weeks (wks), or a high-fat diet (HFD) for 9 or 21 wks; in the 21 wk HFD groups, INT-787 (30 mg/kg/day) dosed via HFD admixture was added. The hepatic ATP, ROS, GSH and MIC19, which stabilizes the structure of inner mitochondrial membrane (IMM), were quantified. Transmission electron microscopy (TEM) analysis was also performed. INT-787 increased hepatic ATP, which was downregulated after HFD 9 and 21 wks. Hepatic ROS increased and GSH decreased after 21 wks and were recovered by INT-787. MIC19 mRNA level decreased after HFD 21 wks, and it was completely restored after INT-787 administration. TEM analysis showed that INT-787 reverted the mitochondrial alterations as documented by restored mitochondrial length, number of mitochondrial cristae junctions (CJs), and distance between endoplasmic reticulum (ER) and outer mitochondrial membrane (OMM) when compared with HFD groups. These results underline the involvement of the FXR pathway in the control of mitochondrial damage, thus revealing a previously undiscovered mechanism mediated by FXR activation: the upregulation of IMM protein MIC19, which is essential for maintaining cristae integrity and mitochondrial function.

Background Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common cause of steatotic liver disease and has major implications on cardiovascular safety. Study aims As the precise role linking MASLD to cardiovascular diseases is still unclear, the present study aims to investigate the association between liver steatosis and fibrosis and circulating plasminogen activator inhibitor-1 (PAI-1) levels. Methods Eighty-two patients (41.6 ± 12.4 yrs, 34 men, 41%), naïve to medications, who attended the Nutrition Center for the Research and Care of Obesity and Metabolic Diseases at the National Institute of Gastroenterology “Saverio de Bellis” for weight management, were cross-sectionally evaluated. Demographic, anthropometric, clinic, and laboratory data were collected and analyzed. All patients underwent liver ultrasonographic assessment by FibroScan to diagnose liver steatosis (controlled attenuation parameter or CAP > 275 dBm) and fibrosis (liver stiffness > 8.2 kPa). Results Sixty-one individuals (74.4%) had liver steatosis, and 17 (20.7%) had liver fibrosis. PAI-1 mean levels were 3,261 ± 1,270 pg/mL, mean body mass index (BMI) and waist circumference (WC) values were 36.6 ± 7.1 kg/m 2 and 114.1 ± 16.5 cm, respectively. Mild systolic and diastolic arterial pressure elevation and significantly high values of fasting plasma insulin (19.6 ± 12.6 IU/mL) and homeostatic model assessment of insulin resistance or HOMA-IR (4.8 ± 3.5) were also found. CAP values were correlated with several anthropometric, clinical, and laboratory parameters of insulin resistance. We found a significant association between PAI-1 and CAP (β = 1.605; p  = 0.004), and noteworthily, when PAI-1 increased by 100 units, the expected variation of CAP values was by + 1.6 units ( p  = 0.004). Notably, the association was independent of gender, age, and insulin resistance. Discussion Circulating PAI-1 levels are correlated with liver steatosis and, to a lesser extent, fibrosis in apparently healthy patients with a BMI ≥ 25 kg/m 2 . This is the first study to show these results in patients naïve to medications, using FibroScan assessment. The bidirectional relationship between circulating PAI-1 levels and CAP measurement highlights the relevance of our research from a diagnostic and pathophysiological-prognostic viewpoint. Longitudinal trials are needed to clarify the cause-effect association between MASLD and PAI-1 levels.

We compared static preservation (cold storage, CS, 4 °C) with dynamic preservation (machine perfusion, MP, 20 °C) followed by reperfusion using marginal livers: a model of donation after cardiac death (DCD) livers and two models of fatty livers, the methionine-choline deficient (MCD) diet model, and obese Zucker (fa/fa) rats. CS injury in DCD livers was reversed by an oxygenated washout (OW): hepatic damage, bile flow, and the ATP/ADP ratio in the OW + CS group was comparable with the ratio obtained with MP. Using fatty livers, CS preservation induced a marked release in hepatic and biliary enzymes in obese Zucker rats when compared with the MCD group. The same trend occurred for bile flow. No difference was found when comparing MP in MCD and obese Zucker rats. Fatty acid analysis demonstrated that the total saturated (SFA)/polyunsaturated fatty acid (PUFA) ratio was, respectively, 1.5 and 0.71 in obese Zucker and MCD rats. While preservation damage in DCD livers is associated with the ATP/ADP recovered with OW, injury in fatty livers is linked to fatty acid constituents: livers from obese. Zucker rats, with greater content in saturated FA, might be more prone to CS injury. On the contrary, MCD livers with elevated PUFA content might be less susceptible to hypothermia.