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Flow-induced vibrations of rigid prisms supported elastically were studied experimentally in a free-surface water channel with a high blockage (2/5). The study focused on finding the prism cross-sectional shape that maximizes the efficiency of energy harvesting. Seven cross-sectional shapes were tested: square, circular, 45° tilted square, equilateral triangle, isosceles 120° triangle, D-section, and C-section. All other dimensionless parameters of the problem, mass ratio, damping, blockage ratio, reduced velocity range, and the Reynolds (Re) number (characteristic velocity times characteristic length divided by kinematic viscosity) range (400–1070), were kept unchanged. By doing so, the effect of the cross-sectional shape was isolated. D-section proved to be the geometry with the highest values of energy transfer efficiency. A hysteresis loop was present in its oscillatory response (dimensionless oscillation amplitude vs reduced velocity). This loop was characterized by two branches, (+) and (−), meaning a bi-valued amplitude response for each reduced velocity. Regarding temporal patterns of wake topology and body motion, it was found that synchronization occurs in the (+) branch, but not in the (−). Regarding vortex shedding modes, particle image velocimetry was used for identification purposes, and it was found that the 2P mode is the dominant mode in the (+) branch, while the 2S mode pervades the (−). Finally, a new relative reduced velocity definition was introduced, and, when re-plotting the experimental results, it was found that the hysteresis loop disappears, thereby providing a more compact mathematical description of the observed phenomena. [ABSTRACT FROM AUTHOR]

An experimental study is presented that addresses the problem of a freely decelerating sphere in a still water tank. The diameter of the sphere was 0.04 m. Three different solid-to-fluid density ratios were considered: 0.78, 0.88, and 0.94. The submerged sphere was impulsively started upon being rammed by an actuator-mass system. Six initial velocities were considered: 0.91, 2.03, 2.54, 2.94, 3.29, and 3.78 m/s. The Reynolds number of the initial velocities based on the sphere diameter was 3.6 × 104, 8.1 × 104, 1.01 × 105, 1.17 × 105, 1.31 × 105, and 1.51 × 105 (subcritical). It was observed that both sphere dynamics and associated flow topology (identified via an optical system and a particle image velocimetry system, respectively) differed significantly from the case of an accelerating sphere. In the present case, a large vortex ring structure (both torus diameters of the order of the sphere's diameter) formed and attached to the sphere surface. This vortex ring followed the sphere motion all the way down the falling trajectory. From the data reduction standpoint, it was found that a suitably defined dimensionless acceleration parameter allowed for collapsing the kinematics variables of the sphere trajectory, namely, position, velocity, and acceleration, into a single ordinary differential equation. [ABSTRACT FROM AUTHOR]

This experiment aimed to evaluate the effects of herbal vitamin C at different levels on tilapia (Oreochromis spp.) growth, potential DNA damage, and the metabolomic profile of water effluent. Forty-five tilapias were housed in separate plastic tanks (80 L), and these were randomly assigned to three treatments: (a) a commercial diet (CD) only; (Nutripec Purina®); (b) the commercial diet plus 250 mg of herbal vitamin C (HVC)/kg (CD250); and (c) the commercial diet plus 500 mg of HVC/kg (CD500). Biometric measurements were taken each week, blood samples were collected from the caudal vein on the final day, and water effluent was taken each week and immediately frozen (−80 °C) until further analysis (gas chromatography/mass spectrometry (GC/MS) systems). Data were completely randomized with a 2 × 2 factorial arrangement of treatments. Upon including herbal vitamin C, the final BW (p = 0.05) and BWG (p = 0.06) increased linearly. Herbal vitamin C decreases DNA damage (p ≥ 0.05). PLS-DA showed a 41.6% variation between treatments in the water samples. Fifteen metabolites had the best association between treatments, with a stronger correlation with CD500. Herbal vitamin C could improve fish performance, prevent DNA damage, and influence changes in the metabolomic profile of the water. [ABSTRACT FROM AUTHOR]

This paper explores the feasibility of using the unsteady forces generated by the Karman street around a microprism in the laminar flow regime as a means to generate mechanical work. In particular, the study has the objective of assessing whether this physical effect could be used for practical energy-harvesting purposes. The confined flow, either of a liquid or a gas, around a rectangular microprism, of which different aspect ratios have been studied, is considered at Reynolds 200 so as to make sure that the Karman street is developed and that the flow remains 2-D. The microprism is allowed to move freely in the direction perpendicular to the flow. The equation of motion of the prism includes a term that simulates its coupling with a vibration-driven micropower generator. Two different couplings have been considered: a velocity-damped resonant generator and a Coulomb-damped resonant generator. Different configurations have been studied, and comparisons have been carried out between them so as to draw a first set of design guidelines. Finally, it is shown that this type of energy-harvesting microdevice, which is basically 2-D, would yield a reasonable compromise between power output, manufacturing simplicity, and cost. [2008-0183] Index Terms--Energy harvesting, laminar unsteady flow, MEMS, microresonator, vibration to energy conversion.

A 3D numerical study is used to analyze the flow topology and performance, in terms of heat transfer efficiency and required pumping power, of heat sink devices with different channel aspect-ratio in the presence of tip-clearance. Seven different channel aspect ratios A R , from 0.25 to 1.75, were analyzed. The flow Reynolds numbers R e , based on the average velocity evaluated in the device channels region, were in the range of 200 to 1000. Two different behaviors of the global Nusselt were obtained depending on the flow Reynolds number: for R e < 600 , the heat transfer increased with the channels aspect ratio, e.g., for R e = 400 , the global Nusselt number increased by 14% for configuration A R = 1.75 when compared to configuration A R = 0.25 . For R e > 600 , the maximum Nusselt is obtained for the squared-channel configuration, and, for some configurations, flow destabilization to a unsteady regime appeared. For R e = 700 , Nusselt number reduced when compared with the squared-channel device, 11% and 2% for configurations with A R = 0.25 and 1.75, respectively. Dimensionless pressure drop decreased with the aspect ratio for all cases. In the context of micro-devices, where the Reynolds number is small, these results indicate that the use of channels with high aspect-ratios is more beneficial, both in terms of thermal and dynamic efficiency. [ABSTRACT FROM AUTHOR]

Autophagy is an evolutionary conserved, degradative process from single-cell eukaryotes, such as Saccharomyces cerevisiae, to higher mammals, such as humans. The regulation of autophagy has been elucidated through the combined study of yeast, Caenorhabditis elegans, mice, Drosophila melanogaster, and humans. MTOR, the major negative regulator of autophagy, and activating nutrient kinases, such as 5'-AMP-activated protein kinase (AMPK), interact with the autophagy regulatory complex: ULK1/2, RB1CC1, ATG13, and ATG101. The ULK1/2 complex induces autophagy by phosphorylating downstream autophagy complexes, such as the BECN1 PIK3 signaling complex that leads to the creation of LC3+ autophagosomes. We highlight in this review various reports of autophagy induction that are independent of these regulators. We discuss reports of MTOR-independent, AMPK-independent, ULK1/2-independent, and BECN1-PIK3C3-independent autophagy. We illustrate that autophagy induction and the components required vary by the nature of the induction signal and type of cell and do not always require canonical members of the autophagy signaling pathway. We illustrate that rather than thinking of autophagy as a linear pathway, it is better to think of autophagy induction as an interconnecting web of key regulators, many of which can induce autophagy through different requirements depending on the type and length of induction signals. [ABSTRACT FROM AUTHOR]

Enterovirus D68 (EV-D68) is a medically important respiratory plus-strand RNA virus of children that has been linked to acute flaccid myelitis. We have determined that EV-D68 induces autophagic signaling and membrane formation. Autophagy, a homeostatic degradative process that breaks down protein aggregates and damaged organelles, promotes replication of multiple plus-strand viruses. Induction of autophagic signals promotes EV-D68 replication, but the virus inhibits the downstream degradative steps of autophagy in multiple ways. EV-D68 proteases cleave a major autophagic cargo adaptor and the autophagic SNARE SNAP29, which reportedly regulates fusion between autophagosome to amphisome/autolysosome. Although the virus inhibits autophagic degradation, SNAP29 promotes virus replication early in infection. An orphan SNARE, SNAP47, is shown to have a previously unknown role in autophagy, and SNAP47 promotes the replication of EV-D68. Our study illuminates a mechanism for subversion of autophagic flux and redirection of the autophagic membranes to benefit EV-D68 replication. [ABSTRACT FROM AUTHOR]

In recent years advances in video-assisted thoracoscopic surgery have been aimed at reducing the number of video surgery ports, and especially major lung resections pose the greatest challenge. We describe a new minimally invasive as well as aesthetic approach for thoracoscopic lobectomy. The technique poses no difficulty for the surgeon and has certain advantages over other videothoracoscopic approaches. [ABSTRACT FROM AUTHOR]

Droplet deformation and breakup in the continuously accelerated flowfield generated by an incoming airfoil have been studied. The upper limit of droplet deformation and the minimum distance to the airfoil model at which the breakup onset takes place have been modeled. Three analytical equations have been developed based on the combination of two models: a droplet deformation and trajectory model for droplets in a continuously accelerated flowfield, and a breakup model for droplets in the vicinity of a leading edge of an airfoil model. The verification was made using experimental data obtained for water droplets whose diameters were in the range from 400 to 1800 µm impinging on airfoils of three different chord sizes moving at velocities from 50 to 90 m/s. The rotating arm facility at National Institute of Aerospace Technology was used for this purpose. The analytical equations of the model were in good agreement with the experimental data. The upper limit of droplet deformation was verified by 95.40% of the tested experimental cases, and the minimum distance to the airfoil was verified in 99.65% of the cases. [ABSTRACT FROM AUTHOR]

A new experimental campaign has been conducted in the shoulder region of an incoming airfoil of chord 1050 mm, where droplets are separated enough to neglect interferences between them. Droplets of three sizes (500, 950, and 1250µm of radius) were allowed to fall in the path of an incoming airfoil while shadowgraph images were recorded by a high-speed video camera at 40,000 fps. The airfoil model was placed at the end of a rotating arm and moved at four velocities (30, 40, 50, and 60m/s). Three different regions of the shoulder were tested. Droplet deformation and trajectories are presented. Droplets evolve as a conjunction of two half-oblate spheroids that tilt as the model approaches. The tilting is larger in the higher regions of the shoulder. The trajectory model derived for droplet in the stagnation line of a moving airfoil has been formally derived for the shoulder region and applied to the experimental data, showing very good agreement being the mean discrepancy less than 4% for the trajectory and 10% for the deformation. [ABSTRACT FROM AUTHOR]

A new breakup criterion is proposed in this paper for droplets subject to the flowfield generated by an incoming airfoil (that is, the criterion should be applied only to this type of aerodynamics flow). This criterion is based on the study of the characteristic times involved in the problem. These are the characteristic external flowfield variation time and the characteristic droplet deformation time. The criterion takes the shape of an empirical correlation that relates the Weber number at the onset of the breakup to the external flowfield and droplet characteristics. Experimental data on the droplet deformation and breakup tests conducted in a rotating arm facility are used to generate the data used to develop the correlation. Droplets, with diameters in the range of 0.3-3.6 mm, are allowed to fall in the path of an incoming airfoil attached to the end of a rotating arm. Airfoil velocities vary between 50 and 90 m/s. The airfoil leading-edge radius varies from 0.030 to 0.103 m. Experiments are recorded with a high-speed camera using the shadowgraph illumination technique. The empirical breakup correlation applies to droplets that break in the bag and stamen mode. Some additional limited data on droplets that break in the bag and the shear mode are analyzed to see how they fit into the correlation. [ABSTRACT FROM AUTHOR]

Objective: Thoraco-abdominal normothermic regional perfusion (TA-NRP) has emerged as a strategy for evaluating and recovering the heart in controlled donation after the circulatory determination of death (cDCDD). However, its impact on lung grafts remains largely unknown. We aimed to assess the impact of TA-NRP on the outcomes of recipients of cDCDD lungs., Methods: This is a retrospective, multicenter, nationwide study describing the outcomes of cDCDD lung transplants (LTs) performed in Spain from January 2021 to November 2023. Patients were divided in two groups based on the recovery technique: TA-NRP with the simultaneous recovery of the heart versus abdominal NRP (A-NRP) without simultaneous heart recovery. The primary endpoint was the incidence of Primary Graft Dysfunction (PGD) grade 3 at 72 hours. Secondary endpoints included the overall incidence of PGD, days on mechanical ventilation, ICU and hospital length of stay, early survival rates, and mid-term outcomes., Results: 283 cDCDD LTs were performed during the study period, 28 (10%) using TA-NRP and 255 (90%) using A-NRP. No differences were observed in the incidence of PGD grade 3 at 72 hours between the TA-NRP and the A-NRP group (0% vs. 7.6%; p=0.231), though the overall incidence of PGD was significantly lower with TA-NRP (14.3%% vs. 41.5%; p=0.005). We found no significant differences between the groups regarding other post-transplant outcome variables., Conclusions: TA-NRP allows the simultaneous recovery of both the heart and the lungs in the cDCDD scenario with appropriate LT outcomes comparable to those observed with the A-NRP approach., (Copyright © 2024. Published by Elsevier Inc.)