46 research outputs found
Ultrasound Stimulations Induce Prolonged Depolarization and Fast Action Potentials in Leech Neurons
Objective: Ultrasound (US) stimulation carries the promise of a selective, reversible, and non-invasive modulation of neural activity without the need for genetic manipulation of neural structures. However, the mechanisms of US-induced generation of action potentials (APs) are still unclear. Methods: Here we address this issue by analyzing intracellularly recorded responses of leech nociceptive neurons to controlled delivery of US. Results: US induced a depolarization linearly accumulating in time and outlasting the duration of the stimulation. Spiking activity was reliably induced for an optimal US intensity range. Moreover, we found that APs induced by US differ in smaller amplitude and faster repolarization from those induced by electrical stimulation in the same cell but display the same repolarization rate. Conclusions: These results shed light on the mechanism by which spikes are induced by US and pave the way for designing more efficient US stimulation patterns
Coordinated Defects in Hepatic Long Chain Fatty Acid Metabolism and Triglyceride Accumulation Contribute to Insulin Resistance in Non-Human Primates
Non-Alcoholic fatty liver disease (NAFLD) is characterized by accumulation of triglycerides (TG) in hepatocytes, which may also trigger cirrhosis. The mechanisms of NAFLD are not fully understood, but insulin resistance has been proposed as a key determinant
Machine learning in clinical and epidemiological research: isn't it time for biostatisticians to work on it?
In recent years, there has been a widespread cross-fertilization between Medical Statistics and Machine Learning (ML) techniques
Efficacy of a new technique - INtubate-RECruit-SURfactant-Extubate - "IN-REC-SUR-E" - in preterm neonates with respiratory distress syndrome: Study protocol for a randomized controlled trial
Background: Although beneficial in clinical practice, the INtubate-SURfactant-Extubate (IN-SUR-E) method is not successful in all preterm neonates with respiratory distress syndrome, with a reported failure rate ranging from 19 to 69 %. One of the possible mechanisms responsible for the unsuccessful IN-SUR-E method, requiring subsequent re-intubation and mechanical ventilation, is the inability of the preterm lung to achieve and maintain an "optimal" functional residual capacity. The importance of lung recruitment before surfactant administration has been demonstrated in animal studies showing that recruitment leads to a more homogeneous surfactant distribution within the lungs. Therefore, the aim of this study is to compare the application of a recruitment maneuver using the high-frequency oscillatory ventilation (HFOV) modality just before the surfactant administration followed by rapid extubation (INtubate-RECruit-SURfactant-Extubate: IN-REC-SUR-E) with IN-SUR-E alone in spontaneously breathing preterm infants requiring nasal continuous positive airway pressure (nCPAP) as initial respiratory support and reaching pre-defined CPAP failure criteria. Methods/design: In this study, 206 spontaneously breathing infants born at 24+0-27+6 weeks' gestation and failing nCPAP during the first 24 h of life, will be randomized to receive an HFOV recruitment maneuver (IN-REC-SUR-E) or no recruitment maneuver (IN-SUR-E) just prior to surfactant administration followed by prompt extubation. The primary outcome is the need for mechanical ventilation within the first 3 days of life. Infants in both groups will be considered to have reached the primary outcome when they are not extubated within 30 min after surfactant administration or when they meet the nCPAP failure criteria after extubation. Discussion: From all available data no definitive evidence exists about a positive effect of recruitment before surfactant instillation, but a rationale exists for testing the following hypothesis: a lung recruitment maneuver performed with a step-by-step Continuous Distending Pressure increase during High-Frequency Oscillatory Ventilation (and not with a sustained inflation) could have a positive effects in terms of improved surfactant distribution and consequent its major efficacy in preterm newborns with respiratory distress syndrome. This represents our challenge. Trial registration: ClinicalTrials.gov identifier: NCT02482766. Registered on 1 June 2015
Diagnosis, treatment and prevention of pediatric obesity: consensus position statement of the Italian Society for Pediatric Endocrinology and Diabetology and the Italian Society of Pediatrics
The Italian Consensus Position Statement on Diagnosis, Treatment and Prevention of Obesity in Children and Adolescents integrates and updates the previous guidelines to deliver an evidence based approach to the disease. The following areas were reviewed: (1) obesity definition and causes of secondary obesity; (2) physical and psychosocial comorbidities; (3) treatment and care settings; (4) prevention.The main novelties deriving from the Italian experience lie in the definition, screening of the cardiometabolic and hepatic risk factors and the endorsement of a staged approach to treatment. The evidence based efficacy of behavioral intervention versus pharmacological or surgical treatments is reported. Lastly, the prevention by promoting healthful diet, physical activity, sleep pattern, and environment is strongly recommended since the intrauterine phase
Core Physics Studies and TRU Burning Potential of a Thorium-based Fuel Fast Reactor
To overcome the stalemate on nuclear waste management in the US, Westinghouse is proposing a “waste-centric” approach. It consists of setting specifics for the nuclear waste aimed at furthering its acceptability from a societal viewpoint and then pursuing the nuclear system with the best potential to satisfy such requirements [1].
Public acceptability of nuclear waste is viewed to be tied to reducing the required isolation time to a viable minimum. In the U-based cycle, the isolation time is dictated primarily by the protracted radiotoxicity of the transuranic (TRU) isotopes that are generated. Switching to a thorium-based cycle is an appealing option for the potential of reducing the production of TRU [2] while efficiently burning the legacy supply [3].
The focus of this study is to assess the impact of various fuel types (i.e. oxide, nitride and metal) on the transmutation performance of a fast reactor (FR) employing thorium fuel
Transuranic Waste Burning Potential of Thorium Fuel in a Fast Reactor
Westinghouse Electric Company (referred to as “Westinghouse” in the rest of this paper) is
proposing a "back-to-front" approach to overcome the stalemate on nuclear waste management
in the US. In this approach, requirements to further the societal acceptance of nuclear waste are
such that the ultimate health hazard resulting from the waste package is “as low as reasonably
achievable”. Societal acceptability of nuclear waste can be enhanced by reducing the long-term
radiotoxicity of the waste, which is currently driven primarily by the protracted radiotoxicity of the
transuranic (TRU) isotopes. Therefore, a transition to a more benign radioactive waste can be
accomplished by a fuel cycle capable of consuming the stockpile of TRU “legacy” waste
contained in the LWR Used Nuclear Fuel (UNF) while generating waste which is significantly
less radiotoxic than that produced by the current open U-based fuel cycle (once through and
variations thereof).
Investigation of a fast reactor (FR) operating on a thorium-based fuel cycle, as opposed to the
traditional uranium-based is performed. Due to a combination between its neutronic properties
and its low position in the actinide chain, thorium not only burns the legacy TRU waste, but it
does so with a minimal production of “new” TRUs. The effectiveness of a thorium-based fast
reactor to burn legacy TRU and its flexibility to incorporate various fuels and recycle schemes
according to the evolving needs of the transmutation scenario have been investigated.
Specifically, the potential for a high TRU burning rate, high U-233 generation rate if so desired
and low concurrent production of TRU have been used as metrics for the examined cycles.
Core physics simulations of a fast reactor core running on thorium-based fuels and burning an
external TRU feed supply have been carried out over multiple cycles of irradiation, separation
and reprocessing. The TRU burning capability as well as the core isotopic content have been
characterized. Results will be presented showing the potential for thorium to reach a high TRU
transmutation rate over a wide variety of fuel types (oxide, metal, nitride and carbide) and
transmutation schemes (recycle or partition of in-bred U-233). In addition, a sustainable scheme
has been devised to burn the TRU accumulated in the core inventory once the legacy TRU
supply has been exhausted, thereby achieving long-term virtually TRU-free