230 research outputs found
A portable electrochemiluminescence aptasensor for β-lactoglobulin detection
Cow’s milk allergy is one of the most common food allergies in children with a prevalence of around 2.5%. Milk contains several allergens; the main ones are caseins and β-lactoglobulin (β-LG). At regulatory level, β-LG is not explicitly named, but milk is included in the list of substances or products causing allergies or intolerances. Hence, the presence of β-LG can be a useful marker for determining the presence of milk in food. In this work, we present an aptasensor based on electrochemiluminescence (ECL) for the quantification of β-LG in real food matrices displaying integrated advantages consisting of high specificity, good sensitivity, portability, and cost effectiveness. The performance and applicability of this sensor were tested by analyzing a sample of skimmed milk and an oat-based drink proposed as a vegetable substitute for milk of animal origin. We obtained a linear correlation between the intensity of the signal and the concentration of β-LG standard solutions (y = x * 0.00653 + 1.038, R2 = 0.99). The limit of detection (LOD) and the limit of quantification (LOQ) were found to be 1.36 and 4.55 μg L−1, respectively. Graphical abstract: [Figure not available: see fulltext.
Room Temperature Ionic Liquids As Useful Overlayers for Estimating Food Quality from Their Odor Analysis by Quartz Crystal Microbalance Measurements
A Study of Channel Model Parameters for Aerial Base Stations at 2.4 GHz in Different Environments
The 5th generation of cellular networks (5G) will provide high speed and high-availability wireless links for communication between mobile users. The usage of aerial platforms as base stations has been recently proposed to meet the above requirements, especially in densely-packed urban areas. To make an accurate prediction of the performance in such a communication system the availability of suitable channel models is a fundamental requirement. Here, we concentrate on a simple path loss and shadow fading channel model that is commonly used to describe the propagation between an aerial base station and a user on the ground. A commercial 3D ray-tracing simulator is used to extract the main parameters used in the model and the Line of Sight/Non Line of Sight probabilities as a function of the transmitter height and elevation angle. We consider three reference scenarios: Suburban, Urban and Urban High Rise generated according to ITU-R specifications. As a novel contribution, we also show simulation results for the spatial correlation of the received signal in the three considered scenarios
Beneficial impact of levosimendan in critically ill patients with or at risk for acute renal failure: a meta-analysis of randomized clinical trials
INTRODUCTION:
The incidence of Acute Kidney Injury is nowadays high in critically ill patients. Its etiology is multifactorial and a primary role is played by low cardiac output syndrome. Everything targeted to normalize cardiac output should increase the renal perfusion and abolish the secondary vasoconstriction. Levosimendan is a calcium sensitizer drug with inotropic properties that improves cardiac output and seems to increase renal blood flow. The aim of this meta-analysis was to evaluate the role of levosimendan in critically ill patients with or at risk of Acute Kidney Injury.
METHODS:
We performed a meta-analysis of randomized controlled trials searching for trials that compared levosimendan with any comparator. The endpoints were the number of patients receiving Renal Replacement Therapy after randomization and the number of patients developing Acute Kidney Injury.
RESULTS:
Final analysis included 33 trials and 3,879 patients (2,024 levosimendan and 1,855 control). The overall analysis showed that the use of levosimendan was associated with a significant reduction in the risk of Renal Replacement Therapy (17 of 492 [3.5%] in the levosimendan group versus 37 of 427 [8.7%] in the control group, relative risk =0.52 [0.32 to 0.86], p for effect =0.01) and of Acute Kidney Injury (114 of 1,598 [7.1%] in the levosimendan group versus 143 of 1,529 [9.4%] in the control arm, relative risk =0.79 [0.63 to 0.99], p for effect =0.048).
CONCLUSIONS:
This meta-analysis suggests that the use of levosimendan is associated with a significant reduction of Renal Replacement Therapy in critically ill patients
Low-frequency cortical activity is a neuromodulatory target that tracks recovery after stroke.
Recent work has highlighted the importance of transient low-frequency oscillatory (LFO; <4 Hz) activity in the healthy primary motor cortex during skilled upper-limb tasks. These brief bouts of oscillatory activity may establish the timing or sequencing of motor actions. Here, we show that LFOs track motor recovery post-stroke and can be a physiological target for neuromodulation. In rodents, we found that reach-related LFOs, as measured in both the local field potential and the related spiking activity, were diminished after stroke and that spontaneous recovery was closely correlated with their restoration in the perilesional cortex. Sensorimotor LFOs were also diminished in a human subject with chronic disability after stroke in contrast to two non-stroke subjects who demonstrated robust LFOs. Therapeutic delivery of electrical stimulation time-locked to the expected onset of LFOs was found to significantly improve skilled reaching in stroke animals. Together, our results suggest that restoration or modulation of cortical oscillatory dynamics is important for the recovery of upper-limb function and that they may serve as a novel target for clinical neuromodulation
Aberrant survival of hippocampal Cajal-Retzius cells leads to memory deficits, gamma rhythmopathies and susceptibility to seizures in adult mice
Cajal-Retzius cells (CRs) are transient neurons, disappearing almost completely in the postnatal neocortex by programmed cell death (PCD), with a percentage surviving up to adulthood in the hippocampus. Here, we evaluate CR’s role in the establishment of adult neuronal and cognitive function using a mouse model preventing Bax-dependent PCD. CRs abnormal survival resulted in impairment of hippocampus-dependent memory, associated in vivo with attenuated theta oscillations and enhanced gamma activity in the dorsal CA1. At the cellular level, we observed transient changes in the number of NPY cells and altered CA1 pyramidal cell spine density. At the synaptic level, these changes translated into enhanced inhibitory currents in hippocampal pyramidal cells. Finally, adult mutants displayed an increased susceptibility to lethal tonic-clonic seizures in a kainate model of epilepsy. Our data reveal that aberrant survival of a small proportion of postnatal hippocampal CRs results in cognitive deficits and epilepsy-prone phenotypes in adulthood.We thank Dr. P. Billuart for critical reading of the manuscript and suggestions during the course of the study, the NeuroImag platform at the IPNP and SFR Necker Imaging and histology platforms at the Imagine Institute for help with acquisition, the animal house facility (LEAT) and Animalliance for animal care. We are grateful to N. Ramezanidoraki and P. Billuart for initiating the first MEA experiment as well as members of the Pierani’s lab for technical support and helpful discussions.We thank Ann Kennedy for mouse profile (Zenodo, 2020) doi:10.5281/zenodo.3925921and for the mouse scheme in Fig. 3a, French Ministry of Research (BioSPc Doctoral school) (M.R.), Fondation pour la recherche médicale, FDT20201201037 (M.R.), Centre national de la
recherche scientifique (CNRS) (A.P.), Agence Nationale de la Recherche, ANR-15-CE16-0003-01, ANR-19-CE16-0017-03 and ANR20-CE16-0001-01 (A.P.), Fondation pour la recherche médicale, Équipe FRM DEQ20130326521 and EQU201903007836) (A.P.), Agence Nationale de la Recherche under “Investissements d’avenir” program, ANR10-IAHU-01) (Imagine Institute), Fondation pour la recherche médicale (F.O.), AGEMED-INSERM (F.O.), NRJ for Neuroscience (F.O.), European Research Council (Consolidator grant #683154) (N. Rouach), European Research Council (Starting Grant #678250) (N. Rebola), Agence Nationale de la Recherche ANR-21-CE16-0020 and ANR-20-CE16-0009 (N. Rebola), and ANR-21-NEU2-0007-01 Eranet-Neuron ROSSINI project (A.P. and L.M.d.l.P.)
Insight into Elderly ALS Patients in the Emilia Romagna Region: Epidemiological and Clinical Features of Late-Onset ALS in a Prospective, Population-Based Study
Few studies have focused on elderly (>80 years) amyotrophic lateral sclerosis (ALS) patients, who represent a fragile subgroup generally not included in clinical trials and often neglected because they are more difficult to diagnose and manage. We analyzed the clinical and genetic features of very late-onset ALS patients through a prospective, population-based study in the Emilia Romagna Region of Italy. From 2009 to 2019, 222 (13.76%) out of 1613 patients in incident cases were over 80 years old at diagnosis, with a female predominance (F:M = 1.18). Elderly ALS patients represented 12.02% of patients before 2015 and 15.91% from 2015 onwards (p = 0.024). This group presented with bulbar onset in 38.29% of cases and had worse clinical conditions at diagnosis compared to younger patients, with a lower average BMI (23.12 vs. 24.57 Kg/m2), a higher progression rate (1.43 vs. 0.95 points/month), and a shorter length of survival (a median of 20.77 vs. 36 months). For this subgroup, genetic analyses have seldom been carried out (25% vs. 39.11%) and are generally negative. Finally, elderly patients underwent less frequent nutritional- and respiratory-supporting procedures, and multidisciplinary teams were less involved at follow-up, except for specialist palliative care. The genotypic and phenotypic features of elderly ALS patients could help identify the different environmental and genetic risk factors that determine the age at which disease onset occurs. Since multidisciplinary management can improve a patient’s prognosis, it should be more extensively applied to this fragile group of patients
Sexual Transmission of a Plant Pathogenic Bacterium, Candidatus Liberibacter asiaticus, between Conspecific Insect Vectors during Mating
Candidatus Liberibacter asiaticus is a fastidious, phloem-inhabiting, gram-negative bacterium transmitted by Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae). The bacterium is the presumed causal agent of huanglongbing (HLB), one of the most destructive and economically important diseases of citrus. We investigated whether Las is transmitted between infected and uninfected D. citri adults during courtship. Our results indicate that Las was sexually transmitted from Las-infected male D. citri to uninfected females at a low rate (<4%) during mating. Sexual transmission was not observed following mating of infected females and uninfected males or among adult pairs of the same sex. Las was detected in genitalia of both sexes and also in eggs of infected females. A latent period of 7 days or more was required to detect the bacterium in recipient females. Rod shaped as well as spherical structures resembling Las were observed in ovaries of Las-infected females with transmission electron microscopy, but were absent in ovaries from uninfected D. citri females. The size of the rod shaped structures varied from 0.39 to 0.67 µm in length and 0.19 to 0.39 µm in width. The spherical structures measured from 0.61 to 0.80 µm in diameter. This investigation provides convincing evidence that a plant pathogenic bacterium is sexually transmitted from male to female insects during courtship and established evidence that bacteria persist in reproductive organs. Moreover, these findings provide an alternative sexually horizontal mechanism for the spread of Las within populations of D. citri, even in the absence of infected host trees
Light Yield in DarkSide-10: a Prototype Two-phase Liquid Argon TPC for Dark Matter Searches
As part of the DarkSide program of direct dark matter searches using liquid
argon TPCs, a prototype detector with an active volume containing 10 kg of
liquid argon, DarkSide-10, was built and operated underground in the Gran Sasso
National Laboratory in Italy. A critically important parameter for such devices
is the scintillation light yield, as photon statistics limits the rejection of
electron-recoil backgrounds by pulse shape discrimination. We have measured the
light yield of DarkSide-10 using the readily-identifiable full-absorption peaks
from gamma ray sources combined with single-photoelectron calibrations using
low-occupancy laser pulses. For gamma lines of energies in the range 122-1275
keV, we get consistent light yields averaging 8.887+-0.003(stat)+-0.444(sys)
p.e./keVee. With additional purification, the light yield measured at 511 keV
increased to 9.142+-0.006(stat) p.e./keVee.Comment: 10 pages, 7 figures, Accepted for publication in Astroparticle
Physic
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