102,105 research outputs found
Analysis of daily extreme temperatures observed in Udine-Castello in the period from 1894 to nowaday
No full textNew perspectives in pediatric dialysis technologies: the case for neonates and infants with acute kidney injury
No full textAdvancements in pediatric dialysis generally rely on adaptation of technology originally developed for adults. However, in the last decade, particular attention has been paid to neonatal extracorporeal therapies for acute kidney care, an area in which technology has made giant strides in recent years. Peritoneal dialysis (PD) is the kidney replacement therapy (KRT) of choice in the youngest age group because of its simplicity and effectiveness. However, extracorporeal blood purification provides more rapid clearance of solutes and faster fluid removal. Hemodialysis (HD) and continuous KRT (CKRT) are thus the most used dialysis modalities for pediatric acute kidney injury (AKI) in developed countries. The utilization of extracorporeal dialysis for small children is associated with a series of clinical and technical challenges which have discouraged the use of CKRT in this population. The revolution in the management of AKI in newborns has started recently with the development of new CKRT machines for small infants. These new devices have a small extracorporeal volume that potentially prevents the use of blood to prime lines and dialyzer, allow a better volume control and the use of small-sized catheter without compromising the blood flow amount. Thanks to the development of new dedicated devices, we are currently dealing with a true “scientific revolution” in the management of neonates and infants who require an acute kidney support
Low-Field Current on Thin Oxides After Constant Current or Irradiation Stresses
No full textLow-field leakage current appears as one of the main issues of very thin oxides, which may lead to the failure of single MOS and complex circuits, long before the oxide catastrophic breakdown. A large amount of work is currently dedicated to investigate how electrical stresses can enhance such a current, but few is known on the effects of ionizing radiation. In a previous work [1], we have shown that a stable leakage current at fields lower than those required for Fowler-Nordheim (FN) tunneling can be measured, even after exposure to radiation. This Radiation Induced Leakage Current (RILC) is similar to the usual Stress Induced Leakage Current (SILC) observed after electrical stresses on MOS devices. In the present work we study RILC after exposure to a 8 MeV electron beam, on devices with different oxide thickness. We investigate the kinetics of the RILC growth with the cumulative dose, and we compare it with the kinetics of the SILC growth with the cumulative injected charge. We also address the RILC dependence from the gate bias applied during the radiation stress, in order to analyze the oxide damage distribution that induces RILC
Noise Characteristics of Radiation-Induced Soft Breakdown Current in Ultrathin oxides
No full textWe have investigated new aspects of the gate leakage current due to radiation-induced soft breakdown (RSB) of thin oxides subjected to heavy-ion irradiation. Temperature and noise characteristics of RSB on MOS capacitors with 3- and 4- nm MOS oxides have been experimentally investigated. We have developed an empirical law to describe quantitatively the temperature dependence of the RSB current. A small activation energy has been found by using an Arrhenius relation, in agreement with the RSB tunneling conduction mechanism. The RSB variation at high temperature has been only estimated, as measurements of RSB oxides easily produced catastrophic breakdown. We have studied the RSB noise and identified different contributions to the characteristic random telegraph noise, correlated with the trapping and conduction characteristics of the RSB spots. An original model has been developed that successfully describes the different probability distributions of the current fluctuations that cannot be simulated by using previous models, such as those based on Levy or Gaussian distributions. Finally, a correlation was established between the shape of the fluctuation distribution and the degradation level of the oxide
Technicalities, current evidence, and clinical indications of hemoadsorption in critically ill children
No full textHemoadsorption devices represent a significant advancement in extracorporeal organ support therapies, enabling the targeted removal of molecules that are not cleared by conventional kidney replacement therapies. Several hemoadsorption devices are currently available, each with distinct characteristics, mechanisms of action, and molecular adsorption profiles that enable their targeted use in a broad range of clinical scenarios in critically ill patients. Their application has recently been explored in pediatric patients with conditions such as septic shock, acute liver failure, hyperinflammatory syndromes, rhabdomyolysis, and intoxications. Preliminary findings suggest both clinical and biochemical improvements, including reduction in severity scores and circulating inflammatory mediators. However, the current body of evidence remains limited, primarily consisting of case reports and small case series, and often lacks robust clinical trial data. In the pediatric population, several challenges persist, including concerns about device sizing, the unintended removal of essential substances, such as medications, nutrients, albumin, and fibrinogen, and the procedural invasiveness, particularly for younger children. Future research should focus on patient stratification to identify those most likely to benefit from hemoadsorption, and on conducting large, multicenter studies to validate its effectiveness and utility in the pediatric setting
Expanding the Spectrum of Extracorporeal Strategies in Small Infants with Hyperammonemia
No full textHyperammonemia is a life-threatening condition mainly due to the neurotoxicity of ammonia. Ammonia scavengers may be insufficient, and extracorporeal treatment may be required. Continuous treatments are preferred, and a high-dose continuous renal replacement therapy (CRRT) must be prescribed to ensure a fast ammonia depletion. Many of the children with hyperammonemia are newborns, with lower blood volume than older children. The majority of the CRRT systems are adult-based, with large extracorporeal priming volumes and inadequate UF control. Recent strides have been made in the development of CRRT systems more suitable for young children with smaller sets to use in adult machines and dedicated monitors for neonates and infants. The main advantage of the machines for adults is the higher dialysis fluid flows, however with greater hemodynamic risks. Pediatric monitors have been designed to reduce the extracorporeal volume and to increase the precision of the treatment. However, they have substantial limitation in clearance performances. In this review, we discuss on current strategies to provide CRRT in newborns and small infants with hyperammonemia. We also presented our experience with the use of CARPEDIEMTM implemented in a CVVHDF modality, boosting the diffusive clearance with a post-replacement convective mechanism
Stress Induced Leakage Current dependence on frequency after voltage pulsed stress
No full textStress Induced Leakage Current (SILC) is one of the major problems found in ultra-thin oxides before the onset of soft or catastrophic breakdown during accelerated life tests. Quite often SILC is measured after constant current (CCS) or constant voltage (CVS) stresses, even though during the device life the operating conditions usually involve alternating, non-constant gate bias. Relatively few works are focused on this point [1]; the present contribution is one of the first addressing the problem of SILC produced by Pulsed Voltage Stress (PVS). Results have been compared with those obtained after CVS, as a function of injected charge and pulse frequency. We have also studied Radiation Induced Leakage Current (RILC) with either pulsed or constant bias voltage applied during irradiation
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