86,629 research outputs found
Stationary states for a two-dimensional singular Schrödinger equation
No full textIn questo articolo studiamo problemi di Dirichlet singolari, lineari e semilineari, della forma in , su , dove è un dominio in e o con (o nonlinearità più generali). In tali problemi bidimensionali emergono alcune difficoltà a causa della non validità della disuguaglianza di Hardy in e a causa delle invarianze dell'equazione . Pertanto opportune condizioni su e sono necessarie al fine di garantire l'esistenza di una soluzione positiva. Per esempio, se è una curva non costante passante per l'origine e è una curva non limitata, allora la disuguaglianza di Hardy vale su qualunque dominio contenuto in e si possono ottenere alcuni risultati di esistenza
On a variational degenerate elliptic problem
No full textIn this paper we study a class of variational degenerate elliptic problems of the form
-div(a(x) Δu) = f(x,u) in Ω,
u = 0 on ∂Ω,
where Ω is a bounded or unbounded domain in R^n, n ≥ 2
Gut microbiota composition and frailty in elderly patients with Chronic Kidney Disease
No full textBackground Frailty is common in older patients affected by chronic kidney disease (CKD). Since gut microbiota (gMB) may contribute to frailty, we explored possible associations between gMB and frailty in CKD. Methods We studied 64 CKD patients (stage 3b-4), categorized as frail (F, 38) and not frail (NF, 26) according to Fried criteria, and 15 controls (C), all older than 65 years. In CKD we assessed serum C-reactive protein, blood neutrophil/lymphocyte ratio, Malnutrition-inflammation Score (MIS); gMB was studied by denaturing gel gradient electrophoresis (DGGE), high-throughput sequencing (16S r-RNA gene), and quantitative real-time PCR (RT-PCR). Results No differences in alpha diversity between CKD and C and between F and NF patients emerged, but high-throughput sequencing showed significantly higher abundance of potentially noxious bacteria (Citrobacter, Coprobacillus, etc) and lower abundance of saccharolytic and butyrate-producing bacteria (Prevotella spp., Faecalibacterium prausnitzii, Roseburia spp.), in CKD respect to C. Mogibacteriaceae family and Oscillospira genus abundance was positively related to inflammatory indices in the whole CKD cohort, while that of Akkermansia, Ruminococcus and Eubacterium genera was negatively related. Compared with NF, in F there was a higher abundance of some bacteria (Mogibacteriacee, Coriobacteriacee, Eggerthella, etc), many of which have been described as more abundant in other diseases. Conclusions These results suggest that inflammation and frailty could be associated to gMB modifications in CKD
Psychotic versus non-psychotic major depressive disorder : a comparative naturalistic study
No full textOBJECTIVE: Psychotic depressed patients were found to have more severe cognitive deficits, poorer treatment response and higher suicidal risk respect to non-psychotic depressives. Aim of the present research was to compare clinical variables and outcome between psychotic and non-psychotic major depressive patients.
METHOD: A sample of 36 major depressed patients was divided into two groups according to the presence of psychotic symptoms. Structured Clinical Interview for DSM (SCID-I) and Hamilton Depression Rating Scale (HAM-D) were administered to the patients at baseline by trained raters. One-way analysis of variance (ANOVAs) and chi-square tests were performed to compare the two groups. Binary logistic regression was performed to assess the risk of lack of response/remission in patients with psychotic symptoms and the risk of developing psychotic symptoms in major depressives with a family history of schizophrenia or bipolar disorder.
RESULTS: Psychotic major depressives presented more severe illness as showed by HAM-D baseline scores (F=17.20, p<0.001), a longer duration of hospitalization (F=7.64, p=0.009) and they were more frequently treated with clomipramine (χ(2)=16.22, p=0.027). Psychotic symptoms were predictive of lack of remission (OR=4.09, p=0.05) and family history of schizophrenia/psychotic bipolar disorder was associated with psychotic major depression (OR=10.81, p=0.04).
CONCLUSIONS: Patients with psychotic symptoms present a more severe course of illness as showed by long hospitalizations and lower rates of remission. Psychotic depressives show more frequently a family history of "major psychoses" suggesting a continuum in psychotic disorders and a genetic association of major psychotic depression with bipolar disorder and schizophrenia
The timescale of solid-state deformation in the Northern Adamello igneous intrusive suite
No full textThe Late Cenozoic Adamello batholith in the Southern Alps records solid-state deformation structures including, in order of decreasing relative age, cooling joints, mylonitic shear zones and cataclasite-pseudotachylyte faults. We constrained the age and the duration of each phase with 40Ar/ 39Ar geochronology. Host-rocks of the Avio granodiorite, sheared cooling joints, mylonites, pseudotachylytes and cataclasites were sampled and characterized through microstructural, mineralogical, µCT and EPMA analyses. The dated K-bearing phases are: (i) magmatic biotite, (ii) biotite and K-feldspar in joints and mylonites, (iii) pseudotachylytes, (iv) hydrothermal K-feldspar in cataclasites. The wall-rock biotite is 33.2 ± 0.2 Ma old, independently of grainsize, overlapping with the age of cooling joints. Bulk biotite-rich mylonites feature agesbetween 32.4 ± 0.5 and 30.8 ± 0.08 Ma. The K-feldspar cementing cataclasite is 26.4 ± 0.6 Ma old. Four pseudotachylyte matrices cluster between 29.7 ± 0.4 and 32.1 ± 1 Ma, one is 25.3 ± 0.2 Ma old. The resolvable difference in age between magmatic biotite and mylonites indicate that biotite is not a thermochronometer, as its age is mostly controlled by deformation and fluid-rock interactions. 40Ar/39Ar ages mostly confirm the relative ages determined from field relations, with mylonites active within a time window of 1.6 Ma and subsequent seismic faulting protracting for more than 6 Ma
Planetary Parameters, XUV Environments, and Mass-loss Rates for Nearby Gaseous Planets with X-Ray-detected Host Stars
No full textWe leverage Gaia DR2 parallactic distances to deliver new or revised estimates of planetary parameters and X-ray irradiation for a distance-limited (less than or similar to 100 pc) sample of 27 gaseous planets (from super-Earths to hot Jupiters) with publicly available Chandra and/or XMM observations, for which we carry out a homogeneous data reduction. For 20 planets with X-ray-detected host stars we make use of the photoionization hydrodynamics code ATES to derive updated atmospheric mass outflow rates. The newly derived masses/radii are not consistent with the exoplanet.eu values for five systems: HD 149026b and WASP-38, for mass, and Au Mic b, HAT-P-20, and HAT-P-2 for radii. Notably, the lower mass implies a (Saturn-like) density of 0.86 +/- 0.09 g cm(-3) for HD 149026b. This independent estimate is consistent with the lowest values reported in the literature. Separately, we report on the X-ray detection of GJ 9827, HD 219134, and LHS 1140 for the first time. The inferred stellar X-ray luminosity of LHS 1140 (1.34(-0.21)(+0.19)x10(26) erg s(-1)) implies that LHS 1140 b is the least irradiated transiting super-Earth known to orbit within the habitable zone of a nearby M dwarf
A historical geomorphological approach to flood hazard management along the shore of an alpine lake (northern Italy)
No full textA project to develop a flood hazard management plan along the east shore of Lago Maggiore was carried out. Several municipal territories along a coastal stretch have been analysed, identifying the rate of water rise and the limits of the submerged areas. This study discusses the overall methodological approach and presents the results for Porto Valtravaglia, as a significant case study. The first step was a detailed analysis of historical events to locate the most frequently damaged sites. Thousands of historical documents on past floods were collected, selected and validated, to map the most vulnerable sites. The second step was a morphological analysis of the studied coastal stretch. Multi-temporal aerial snap-shots were used and field surveys were conducted to verify the reliability of the historical data and to identify the critical hydraulic conditions along the shore. The third step was a review of the general urban development plans of the 17 studied municipalities. Aerophotogrammetric and cadastral maps were used to evidence and define the eight classes of land use destinations. In addition, the floodable areas were divided into three vulnerability and exposure categories considering different peculiarities of social and working life. Finally, using GIS spatial analysis tools, these data were compiled into risk maps and wielded as the municipal emergency plans’ baseline scenarios. For each studied municipality was hypothesised the alarm thresholds upon which were activated the flood emergency procedures
Motor evoked potentials and bispectral index-guided anaesthesia in image-guided mini-invasive neurosurgery of supratentorial tumors nearby the cortico-spinal tract
No full textAIM: To describe and evaluate the anaesthesiological regimen used in neurophysiologically monitored image-guided mini-invasive neurosurgery. MATERIAL and METHODS: Twenty-four patients underwent elective surgery under general anaesthesia that was administered through Target Controlled Infusion (TCI) for effect-site concentration (Ce) of Propofol and Remifentanil, targeting the Bispectral Index (BIS) in the 40-60 intervals. The stimulating intensity of transcranial motor evoked potentials (tMEP), BIS, Propofol and Remifentanil Ce were collected at MEPs threshold (T) definition (respectively BIS@T, CeProp@T and CeRemi@T). Intraoperative seizure, explicit recall for intraoperative awareness and clinical motor status were assessed. RESULTS: CeProp@T and CeRemi@T ranged respectively between 1.5-2.2 μg/ml (Median 1.6 μg/ml) and 3.5-18 ng/ml (Median 8 ng/ml) that were effective in keeping the BIS@T between 40 and 60 in all surgeries. tMEP thresholds ranged between 45 and 120 mA. There was no correlation between CeProp@T, CeRemi@T and tMEP, as well as between BIS@T and respectively tMEP, CeProp@T, CeRemi@T. None of patients had induced electrical seizure or explicit recalls. Motor scores were equal to preoperative values in 22/24 patients. CONCLUSION: BIS-guided general anaesthesia within a 40-60 interval, with low Ce of Propofol (<2 μ/ml) and high analgesic regime allow reliable tMEP measurements, avoiding postoperative neurological impairment and major adverse outcomes, such as seizure and awareness
Investigating the functional neuroanatomy of concrete and abstract word processing through direct electric stimulation (DES) during awake surgery
No full textNeuropsychological, neuroimaging and electrophysiological studies demonstrate that abstract and concrete word processing relies not only on the activity of a common bilateral network but also on dedicated networks. The neuropsychological literature has shown that a selective sparing of abstract relative to concrete words can be documented in lesions of the left anterior temporal regions. We investigated concrete and abstract word processing in 10 patients undergoing direct electrical stimulation (DES) for brain mapping during awake surgery in the left hemisphere. A lexical decision and a concreteness judgment task were added to the neuropsychological assessment during intra-operative monitoring. On the concreteness judgment, DES delivered over the inferior frontal gyrus significantly decreased abstract word accuracy while accuracy for concrete words decreased when the anterior temporal cortex was stimulated. These results are consistent with a lexical–semantic model that distinguishes between concrete and abstract words related to different neural substrates in the left hemisphere
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