435 research outputs found
Magmatic Signature in Submarine Hydrothermal Fluids Vented Offshore Ventotene and Zannone Islands (Pontine Archipelago, Central Italy)
Geochemical investigations carried out on submarine hydrothermal fluids vented offshore the Pontine Islands (Tyrrhenian Sea) revealed the existence of gas vents to the W of Zannone Island and SW of Ventotene Island. The geochemical features of the CO2-rich gas samples show a clear mantle-derived signature with3He/4He of 3.72-3.75 Ra and 1.33 Ra at Zannone and Ventotene, respectively. Gas geochemistry denotes how CO2-rich gases undergo fractionation processes due to CO2dissolution to a variable extent favoring enrichment in the less soluble gas species, i.e., CH4, N2, and He. The carbon isotope composition of CO2, expressed asδ13C vs. V-PDB, ranges from -0.71 and -6.16‰ at Zannone to 1.93‰ at Ventotene. Preliminary geothermometric and geobarometric estimations indicate equilibrium temperatures in the range of 150-200°C at Zannone and >200°C at Ventotene besides H2O pressures in the range of 5 bar and 20 bar at Zannone and Ventotene, respectively. Although the latest volcanic activity at the Pontine Archipelago is dated Middle Pleistocene, the combination of the new geochemical information along with geothermometric estimations indicates that cooling magmas are likely releasing enough thermal energy to form an efficient hydrothermal system
Radial neck fractures in children: results when open reduction is indicated
BACKGROUND: Radial neck fractures in children are rare, representing 5% of all elbow pediatric fractures. Most are minimally displaced or nondisplaced. Severely displaced or angulated radial neck fractures often have poor outcomes, even after open reduction, and case series reported in literature are limited. The aim of the study is to analyze the outcomes of patients with a completely displaced and angulated fracture who underwent open reduction when closed reduction failed. METHODS: Between 2000 and 2009, 195 patients with radial neck fractures were treated in our institute. Twenty-four cases satisfied all the inclusion criteria and were evaluated clinically and radiologically at a mean follow-up of 7 years. At follow-up, the carrying angle in full elbow extension and the range of motion of the elbow and forearm were measured bilaterally. We recorded clinical results as good, fair, or poor according to the range of movement and the presence of pain. Radiographic evaluation documented the size of the radial head, the presence of avascular necrosis, premature physeal closure, and cubitus valgus. RESULTS: Statistical analysis showed that fair and poor results are directly correlated with loss of pronation-supination (P=0.001), reduction of elbow flexion-extension (P=0.001), increase of elbow valgus angle (P=0.002), necrosis of the radial head (P=0.001), premature physeal closure (P=0.01), and associated lesions (olecranon fracture with or without dislocation of the elbow) (P=0.002). DISCUSSION: In our cases, residual radial head deformity due to premature closure of the growth plate and avascular necrosis were correlated with a functional deficit. Associated elbow injury was coupled with a negative prognosis. In our series, about 25% of patients had fair and 20% had poor results. Outcomes were good in 55% and felt to represent a better outcome than if the fracture remained nonanatomically reduced with residual angulation and/or displacement of the radial head. This study reports the largest series of these fractures with a combination of significant angulation and displacement of the fracture requiring open reduction. We feel that open reduction is indicated when the head of the radius is completely displaced and without contact with the rim of the metaphysis
Hazard Scenarios Related to Submarine Volcanic-Hydrothermal Activity and Advanced Monitoring Strategies: A Study Case from the Panarea Volcanic Group (Aeolian Islands, Italy)
Geohazards associated to submarine hydrothermal systems still represent a tricky enigma to face and solve for the scientific community. The poor knowledge of a submarine environment, the rare and scarce monitoring activities, and the expensive and sometimes complicated logistics are the main problems to deal with. The submarine low-energy explosion, which occurred last November 3, 2002, off the volcanic island of Panarea, highlighted the absence of any hazard scenario to be used to manage the volcanic crisis. The "unrest" of the volcanic activity was triggered by a sudden input of deep magmatic fluids, which caused boiling water at the sea surface with a massive CO2 release besides changes in the fluids' geochemistry. That event dramatically pushed scientists to develop new methods to monitor the seafloor venting activity. Coupling the information from geochemical investigations and data collected during the unrest of volcanic activity, we were able to (a) develop theoretical models to gain a better insight on the submarine hydrothermal system and its relationships with the local volcanic and tectonic structures and (b) to develop a preliminary submarine volcanic hazard assessment connected to the Panarea system (Aeolian Islands). In order to mitigate the potential submarine volcanic hazard, three different scenarios are described here: (1) ordinary hydrothermal venting, (2) gas burst, and (3) volcanic eruption. The experience carried out at Panarea demonstrates that the best way to face any submarine volcanic-hydrothermal hazard is to improve the collection of data in near real-time mode by multidisciplinary seafloor observatories and to combine it with periodical sampling activity
A Proposed Search for the Detection of Gravitational Waves from Eccentric Binary Black Holes
Most of compact binary systems are expected to circularize before the
frequency of emitted gravitational waves (GWs) enters the sensitivity band of
the ground based interferometric detectors. However, several mechanisms have
been proposed for the formation of binary systems, which retain eccentricity
throughout their lifetimes. Since no matched-filtering algorithm has been
developed to extract continuous GW signals from compact binaries on orbits with
low to moderate values of eccentricity, and available algorithms to detect
binaries on quasi-circular orbits are sub-optimal to recover these events, in
this paper we propose a search method for detection of gravitational waves
produced from the coalescences of eccentric binary black holes (eBBH). We study
the search sensitivity and the false alarm rates on a segment of data from the
second joint science run of LIGO and Virgo detectors, and discuss the
implications of the eccentric binary search for the advanced GW detectors
Transcranial static magnetic field stimulation can modify disease progression in Amyotrophic Lateral Sclerosis
[no abstract available
Cost of illness of advanced ovarian carcinoma in Italy: results of an empirical, single-centre study
AIM: To perform an empirical, single-centre, retrospective and secondary cost of illness (COI) study of advanced ovarian carcinoma (AOC) in Italy. METHODS: Demographic, clinical, health care and non-health care resource consumption data concerning a convenience sample of subsequent patients in 1st line of treatment (100 patients), 2nd line of treatment A (surgery + chemotherapy; 30 patients) and 2nd line of treatment B (chemotherapy only; 20 patients) were obtained from a database created in 2011 by the Obstetrics and Ginecology Unit at Campus Biomedico teaching hospital, Rome. Patients were followed-up for 2 years. Resources were valued according to the above mentioned database and literature, following the societal viewpoint. Costs are expressed in Euro (€) 2014 and reported as mean and standard deviation (SD). RESULTS: One-year COI for 1st line of treatment reaches € 44,999.7 (SD: €28,757.3), € 55,410.8 (SD: € 32,454.6) and €46,895.6 (SD: € 28,407.4) for 2nd line of treatment A and B, respectively. Regardless the line of treatment, COI is mainly driven by cost borne by patient and her family. Due to the high costs of relapse the mean COI per patient after 2 years from the diagnosis of AOC equals € 81,869.4 (SD: € 30,660.9), or 182% of the COI for the 1st line of treatment. CONCLUSIONS: Despite some limitations, our results show that increasing progression-free survival could well reduce the COI for AOC in Italy
Intracortical and interhemispheric excitability changes in arm amputees: A TMS study
Objective: To evaluate cortical circuits and excitability of the motor cortex in the hemisphere contralateral to the affected (AH) and to the unaffected arm (UH), in upper limb amputees. Methods: Motor evoked potentials (MEP) were recorded in 17 subjects who had upper limb amputation: 11 trans-radial (TR) and 6 trans-humeral (TH). Motor thresholds (MT), short interval intracortical inhibition (SICI), and interhemispheric inhibition (IHI) in the available arm muscles of the stump were evaluated. Results: There was no significant difference in MT between hemispheres. SICI was preserved in TR but not in TH group. Additionally, in the TR group, the MEP amplitudes in AH were higher than in UH. A significant IHI was observed in the whole sample but not in each hemisphere or patient group. Conclusions: In our population of TR amputees, we found increased corticospinal excitability in the AH with preserved intracortical inhibition. This finding was not observed in the TH population. Significance: Understanding the changes in intracortical excitability in amputees may enhance knowledge of the functional reorganization of the brain in the post-amputation phase, bringing useful information for prosthetic rehabilitation
A comprehensive review of transcranial magnetic stimulation in secondary dementia
Although primary degenerative diseases are the main cause of dementia, a non-negligible proportion of patients is affected by a secondary and potentially treatable cognitive disorder. Therefore, diagnostic tools able to early identify and monitor them and to predict the response to treatment are needed. Transcranial magnetic stimulation (TMS) is a non-invasive neurophysiological technique capable of evaluating in vivo and in "real time" the motor areas, the cortico-spinal tract, and the neurotransmission pathways in several neurological and neuropsychiatric disorders, including cognitive impairment and dementia. While consistent evidence has been accumulated for Alzheimer's disease, other degenerative cognitive disorders, and vascular dementia, to date a comprehensive review of TMS studies available in other secondary dementias is lacking. These conditions include, among others, normal-pressure hydrocephalus, multiple sclerosis, celiac disease and other immunologically mediated diseases, as well as a number of inflammatory, infective, metabolic, toxic, nutritional, endocrine, sleep-related, and rare genetic disorders. Overall, we observed that, while in degenerative dementia neurophysiological alterations might mirror specific, and possibly primary, neuropathological changes (and hence be used as early biomarkers), this pathogenic link appears to be weaker for most secondary forms of dementia, in which neurotransmitter dysfunction is more likely related to a systemic or diffuse neural damage. In these cases, therefore, an effort toward the understanding of pathological mechanisms of cognitive impairment should be made, also by investigating the relationship between functional alterations of brain circuits and the specific mechanisms of neuronal damage triggered by the causative disease. Neurophysiologically, although no distinctive TMS pattern can be identified that might be used to predict the occurrence or progression of cognitive decline in a specific condition, some TMS-associated measures of cortical function and plasticity (such as the short-latency afferent inhibition, the short-interval intracortical inhibition, and the cortical silent period) might add useful information in most of secondary dementia, especially in combination with suggestive clinical features and other diagnostic tests. The possibility to detect dysfunctional cortical circuits, to monitor the disease course, to probe the response to treatment, and to design novel neuromodulatory interventions in secondary dementia still represents a gap in the literature that needs to be explored
Field reconstruction in large aperture quadrupole magnets
A technique to interpolate complex three-dimensional field distributions such as those produced by large magnets is presented. It is based on a modified charge density method where the elementary sources of the magnetic field are image charges with Gaussian shape placed on a three-dimensional surface. The strengths of the charges are found as the solution of a best-fit problem, whose special features are discussed in detail. The method is tested against the measured field of the MAGNEX large acceptance quadrupole, showing a high level of accuracy together with an effective compensation of the effect of the experimental errors present in the data. In addition the model field is in general analytical and Maxwellian. As a consequence, the reliability of the presented technique to the challenging problem of trajectory reconstruction in modern large acceptance spectrometers is demonstrated
MiRNAs and piRNAs from bone marrow mesenchymal stem cell extracellular vesicles induce cell survival and inhibit cell differentiation of cord blood hematopoietic stem cells: a new insight in transplantation
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