469 research outputs found
"Test-site operations for the health monitoring of railway ballast using Ground-Penetrating Radar"
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Single prazosin infusion in prelimbic cortex Fosters extinction of amphetamine-induced conditioned place preference
Exposure to drug-associated cues to induce extinction is a useful strategy to contrast cue-induced drug seeking. Norepinephrine (NE) transmission in medial prefrontal cortex has a role in the acquisition and extinction of conditioned place preference induced by amphetamine. We have reported recently that NE in prelimbic cortex delays extinction of amphetamine-induced conditioned place preference (CPP). A potential involvement of α1-adrenergic receptors in the extinction of appetitive conditioned response has been also suggested, although their role in prelimbic cortex has not been yet fully investigated. Here, we investigated the effects of the α1-adrenergic receptor antagonist prazosin infusion in the prelimbic cortex of C57BL/6J mice on expression and extinction of amphetamine-induced CPP. Acute prelimbic prazosin did not affect expression of amphetamine-induced CPP on the day of infusion, while in subsequent days it produced a clear-cut advance of extinction of preference for the compartment previously paired with amphetamine (Conditioned stimulus, CS). Moreover, prazosin-treated mice that had extinguished CS preference showed increased mRNA expression of brain-derived neurotrophic factor (BDNF) and post-synaptic density 95 (PSD-95) in the nucleus accumbens shell or core, respectively, thus suggesting that prelimbic α1-adrenergic receptor blockade triggers neural adaptations in subcortical areas that could contribute to the extinction of cue-induced drug-seeking behavior. These results show that the pharmacological blockade of α1-adrenergic receptors in prelimbic cortex by a single infusion is able to induce extinction of amphetamine-induced CPP long before control (vehicle) animals, an effect depending on contingent exposure to retrieval, since if infused far from or after reactivation it did not affect preference. Moreover, they suggest strongly that the behavioral effects depend on post-treatment neuroplasticity changes in corticolimbic network, triggered by a possible âprimingâ effect of prazosin, and point
to a potential therapeutic power of the antagonist for maladaptive memories
Capsule endoscopy in pediatrics: a 10-years journey.
Video capsule endoscopy (CE) for evaluation the esophagus (ECE), small bowel (SBCE) and the colon (CCE) is particularly useful in pediatrics, because this imaging modality does not require ionizing radiation, deep sedation or general anesthesia. The risk of capsule retention appears to be dependent on indication rather than age and parallels the adult experience by indication, making SBCE a relatively safe procedure with a significant diagnostic yield. The newest indication, assessment of mucosal change, greatly enhances and expands its potential benefit. The diagnostic role of CE extends beyond the SB. The use of ECE also may enhance our knowledge of esophageal disease and assist patient care. Colon CCE is a novel minimally invasive and painless endoscopic technique allowing exploration of the colon without need for sedation, rectal intubation and gas insufflation. The limited data on ECE and CCE in pediatrics does not yet allow the same conclusions regarding efficacy; however, both appear to provide safe methods to assess and monitor mucosal change in their respective areas with little discomfort. Moreover, although experience has been limited, the patency capsule may help lessen the potential of capsule retention; and newly researched protocols for bowel cleaning may further enhance CE's diagnostic yield. However, further research is needed to optimize the use of the various CE procedures in pediatric populations
First Phase Space Portrait of a Hierarchical Stellar Structure in the Milky Way
We present the first detailed observational picture of a possible ongoing
massive cluster hierarchical assembly in the Galactic disk as revealed by the
analysis of the stellar full phase-space (3D positions and kinematics and
spectro-photometric properties) of an extended area ( diameter)
surrounding the well-known and Persei double stellar cluster in
the Perseus Arm. Gaia-EDR3 shows that the area is populated by seven co-moving
clusters, three of which were previously unknown, and by an extended and quite
massive () halo. All stars and clusters define a complex
structure with evidence of possible mutual interactions in the form of
intra-cluster over-densities and/or bridges. They share the same chemical
abundances (half-solar metallicity) and age ( Myr) within a small
confidence interval and the stellar density distribution of the surrounding
diffuse stellar halo resembles that of a cluster-like stellar system. The
combination of these evidences suggests that stars distributed within a few
degrees from and Persei are part of a common, sub-structured
stellar complex that we named LISCA I. Comparison with results obtained through
direct -body simulations suggest that LISCA I may be at an intermediate
stage of an ongoing cluster assembly that can eventually evolve in a relatively
massive (a few ) stellar system. We argue that such cluster
formation mechanism may be quite efficient in the Milky Way and disk-like
galaxies and, as a consequence, it has a relevant impact on our understanding
of cluster formation efficiency as a function of the environment and redshift.Comment: 19 pages, 8 figures, 1 table; accepted for publication in Ap
MoS2/VO2 vdW heterojunction devices: Tunable rectifiers, photodiodes and field effect transistors
In this work we report a new class of ultra-thin film devices based on n-n van der Waals (vdW) heteroj unctions of MoS2 and VO2, which show remarkable tunable characteristics. The favorable band alignment combined with the sharp and clean vdW interface determines a tunable diode-like characteristic with a rectification ratio larger than 103. Moreover, the heterojunction can be turned into a Schottky rectifier with higher on-current by triggering the VO2 insulator to metal transition (IMT), by either applying a sufficiently large voltage or increasing the temperature above 68 °C. The proposed devices are photosensitive with linear photoresponse and temperature tunable photoresponsivity values larger than 1 in the 500/650 nm wavelength range. We finally report the first ever field-effect transistor based on gated MoS2/VO2 heterojunctions, which is a true low power FET exploiting a phase change material where the electrostatic doping effect of the gate on the junction results in a subthreshold slope (SS) of 130 mV/dec at room temperature, ION/IOFF > 103 and IoFF <; 5 pA/Όm at Vd = 1.5V
Outcome of COVID-19 patients with haematological malignancies after the introduction of vaccination and monoclonal antibodies. Results from the HM-COV 2.0 study
Patients with haematological malignancies (HM) and SARS-CoV-2 infection present a higher risk of severe COVID-19 and mortality. The aim of the study was to investigate whether vaccination and monoclonal antibodies (mAbs) have modified the outcomes of HM patients with COVID-19. This is a single-centre retrospective study in HM patients hospitalized due to SARS-CoV-2 infection from March 2020 to April 2022. Patients were divided into PRE-V-mAb group (patients hospitalized before the introduction of vaccination and mAbs) and POST-V-mAb group (patients hospitalized after the use of vaccine and mAbs). A total of 126 patients were included (65 PRE-V-mAb and 61 POST-V-mAb). POST-V-mAb patients showed a significantly lower risk of intensive care unit (ICU) admission (8.2% vs. 27.7%, p = 0.005), shorter viral shedding [17 (IQR 10â28) vs. 24 days (IQR 15â50), p = 0.011] and shorter hospitalization length [13 (IQR 7â23) vs. 20 (IQR 14â41) days, p = 0.0003] compared to the PRE-V-mAb group. Nevertheless, both in-hospital and 30-day mortality rates did not significantly differ between the two groups (29.5% POST-V-mAb vs. 36.9% PRE-V-mAb and 21.3% POST-V-mAb vs. 29.2% PRE-V-mAb, respectively). At the multivariable analysis, an active malignancy (p = 0.042), a critical COVID-19 at admission (p = 0.025) and the need for high-level of oxygen support at respiratory worsening [either HFNC/CPAP (p = 0.022) or mechanical ven- tilation (p = 0.011)] were independently associated with in-hospital mortality. In the subgroup of POST-V-mAb patients, receiving therapy with mAbs was a protective factor (p = 0.033). Despite the new therapeutic and preventive strategies avail- able, HM patients with COVID-19 disease represent an extremely vulnerable group with still high mortality rates
Quality performance measures for small capsule endoscopy: Are the ESGE quality standards met?
Background and study aims The European Society of Gastrointestinal Endoscopy (ESGE) recently issued a quality performance measures document for small bowel capsule endoscopy (SBCE). The aim of this nationwide survey was to explore SBCE practice with ESGE quality measures as a benchmark.
Patients and methods A dedicated per-center semiquantitative questionnaire based on ESGE performance measures for SBCE was created by a group of SBCE experts. One-hundred-eighty-one centers were invited to participate and were asked to calculate performance measures for SBCE performed in 2018. Data were compared with 10 ESGE quality standards for both key and minor performance measures.
Results Ninety-one centers (50.3 %) participated in the data collection. Overall in the last 5 years (2014â2018), 26,615 SBCEs were performed, 5917 of which were done in 2018. Eighty percent or more of the participating centers reached the minimum standard established by the ESGE Small Bowel Working Group (ESBWG) for four performance measures (indications for SBCE, complete small bowel evaluation, diagnostic yield and retention rate). Conversely, compliance with six minimum standards established by ESBWG concerning adequate bowel preparation, patient selection, timing of SBCE in overt bleeding, appropriate reporting,
reading protocols and referral to device-assisted enteroscopy was met by only 15.5%, 10.9%, 31.1%, 67.7%, 53.4%, and 32.2% of centers, respectively.
Conclusions The present survey shows significant variability across SBCE centers; only four (4/10: 40 %) SBCE procedural minimum standards were met by a relevant proportion of the centers ( â„ 80 %). Our data should help in identifying target areas for quality improvement programs in SBCE
Van der Waals MoS2/VO2 heterostructure junction with tunable rectifier behavior and efficient photoresponse
Junctions between n-type semiconductors of different electron affinity show rectification if the junction is abrupt enough. With the advent of 2D materials, we are able to realize thin van der Waals (vdW) heterostructures based on a large diversity of materials. In parallel, strongly correlated functional oxides have emerged, having the ability to show reversible insulator-to-metal (IMT) phase transition by collapsing their electronic bandgap under a certain external stimulus. Here, we report for the first time the electronic and optoelectronic characterization of ultra-thin n-n heterojunctions fabricated using deterministic assembly of multilayer molybdenum disulphide (MoS2) on a phase transition material, vanadium dioxide (VO2). The vdW MoS2/VO2 heterojunction combines the excellent blocking capability of an n-n junction with a high conductivity in on-state, and it can be turned into a Schottky rectifier at high applied voltage or at temperatures higher than 68â°C, exploiting the metal state of VO2. We report tunable diode-like current rectification with a good diode ideality factor of 1.75 and excellent conductance swing of 120âmV/dec. Finally, we demonstrate unique tunable photosensitivity and excellent junction photoresponse in the 500/650ânm wavelength range
Tunable RF phase shifters based on Vanadium Dioxide metal insulator transition
This paper presents the design, fabrication, and electrical characterization of a reconfigurable RF capacitive shunt switch that exploits the electro-thermally triggered vanadium dioxide (VO2) insulator to metal phase transition. The RF switch is further exploited to build wide-band RF true-time delay tunable phase shifters. By triggering the VO2 switch insulator to metal transition (IMT), the total capacitance can be reconfigured from the series of two metal-insulator-metal (MIM) capacitors to a single MIM capacitor. The effect of bias voltage on losses and phase shift is investigated, explained, and compared to the state of the art in the field. We report thermal actuation of the devices by heating the devices above VO2 IMT temperature. By cascading multiple stages a maximum of 40° per dB loss close to 7 GHz were obtained
Near-infrared emission line diagnostics for AGN from the local Universe to redshift 3
Optical rest-frame spectroscopic diagnostics are usually employed to
distinguish between star formation and AGN-powered emission. However, this
method is biased against dusty sources, hampering a complete census of the AGN
population across cosmic epochs. To mitigate this effect, it is crucial to
observe at longer wavelengths in the rest-frame near-infrared (near-IR), which
is less affected by dust attenuation and can thus provide a better description
of the intrinsic properties of galaxies. AGN diagnostics in this regime have
not been fully exploited so far, due to the scarcity of near-IR observations of
both AGNs and star-forming galaxies, especially at redshifts higher than 0.5.
Using Cloudy photoionization models, we identify new AGN - star formation
diagnostics based on the ratio of bright near-infrared emission lines, namely
[SIII] 9530 Angstrom, [CI] 9850 Angstrom, [PII] 1.188 , [FeII] , and [FeII] to Paschen lines (either Pa or
Pa), providing simple, analytical classification criteria. We apply
these diagnostics to a sample of 64 star-forming galaxies and AGNs at 0 < z <
1, and 65 sources at 1 < z < 3 recently observed with JWST-NIRSpec in CEERS. We
find that the classification inferred from the near-infrared is broadly
consistent with the optical one based on the BPT and the [SII]/H ratio.
However, in the near-infrared, we find more AGNs than in the
optical (13 instead of 8), with 5 sources classified as 'hidden' AGNs, showing
a larger AGN contribution at longer wavelengths, possibly due to the presence
of optically thick dust. The diagnostics we present provide a promising tool to
find and characterize AGNs from z=0 to z=3 with low and medium-resolution
near-IR spectrographs in future surveys.Comment: Paper accepted for publication in A&A on 05/09/2023. Three public
Github repositories include: (1) a table with emission line measurements for
the paper sample : https://github.com/Anthony96/Line_measurements_nearIR ,
Cloudy emission line predictions for star-forming galaxies and AGN models :
https://github.com/Anthony96/star-forming_models ,
https://github.com/Anthony96/AGN_model
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